U.S. patent application number 15/183556 was filed with the patent office on 2016-11-03 for illumination light source device including a reflecting-transmitting element, projection device including the illumination light source device and method to control the projection device.
The applicant listed for this patent is Kazuhiro FUJITA, lkuo MAEDA, Toshiharu MURAI, Takehiro NISHIMORI, Tatsuya TAKAHASHI. Invention is credited to Kazuhiro FUJITA, lkuo MAEDA, Toshiharu MURAI, Takehiro NISHIMORI, Tatsuya TAKAHASHI.
Application Number | 20160320692 15/183556 |
Document ID | / |
Family ID | 50232975 |
Filed Date | 2016-11-03 |
United States Patent
Application |
20160320692 |
Kind Code |
A1 |
TAKAHASHI; Tatsuya ; et
al. |
November 3, 2016 |
ILLUMINATION LIGHT SOURCE DEVICE INCLUDING A
REFLECTING-TRANSMITTING ELEMENT, PROJECTION DEVICE INCLUDING THE
ILLUMINATION LIGHT SOURCE DEVICE AND METHOD TO CONTROL THE
PROJECTION DEVICE
Abstract
An illumination light source device includes a
reflection-transmission wheel provided on a light-path from an
excitation light source and having a transmission region that
transmits an excitation light and a reflection region reflecting
the excitation light, a fluorescent wheel provided on at least one
of the reflection light-path and the transmission light-path and
having a fluorescent body emitting fluorescence when excited by the
excitation light, and a control section turning-on the excitation
light source while the boundary of the transmission region and the
reflection region traverses the light-path, in order to provide an
illumination light source device capable of preventing a
deterioration of the fluorescent body, whereby improving a color
reproducibility by use of the color mixture occurred at the
boundary region between the transmission light-path and the
reflection light-path effectively and improving the brightness of
image.
Inventors: |
TAKAHASHI; Tatsuya; (Tokyo,
JP) ; FUJITA; Kazuhiro; (Tokyo, JP) ; MURAI;
Toshiharu; (Kanagawa, JP) ; MAEDA; lkuo;
(Kanagawa, JP) ; NISHIMORI; Takehiro; (Kanagawa,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TAKAHASHI; Tatsuya
FUJITA; Kazuhiro
MURAI; Toshiharu
MAEDA; lkuo
NISHIMORI; Takehiro |
Tokyo
Tokyo
Kanagawa
Kanagawa
Kanagawa |
|
JP
JP
JP
JP
JP |
|
|
Family ID: |
50232975 |
Appl. No.: |
15/183556 |
Filed: |
June 15, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
14014976 |
Aug 30, 2013 |
9400416 |
|
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15183556 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F21V 14/08 20130101;
F21K 9/62 20160801; G03B 33/08 20130101; F21V 13/08 20130101; G09G
3/3413 20130101; G03B 21/204 20130101; F21V 7/00 20130101; G03B
21/142 20130101; F21Y 2115/30 20160801 |
International
Class: |
G03B 21/20 20060101
G03B021/20; F21V 7/00 20060101 F21V007/00; G09G 3/34 20060101
G09G003/34; F21V 23/00 20060101 F21V023/00; F21V 14/08 20060101
F21V014/08; G03B 33/08 20060101 G03B033/08; F21V 13/08 20060101
F21V013/08; F21K 9/62 20060101 F21K009/62 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 12, 2012 |
JP |
2012-200234 |
Claims
1. (canceled)
2. An illumination light source device comprising: a
reflection-transmission member provided on an exit light path of an
excitation light from an excitation light source and having a
transmission region transmits an excitation light as an optical
wavelength and a reflection region reflecting the excitation light
from the excitation light source, in which the transmission region
and the reflection region sequentially traverses the exit light
path of the excitation light from the excitation light source; a
fluorescent body member provided on at least one of the reflection
light path formed of the reflection region and the transmission
light path formed of the transmission region and having a
fluorescent body emitting fluorescence when excited by the
excitation light; and a control section turning-on the excitation
light source and leading the excitation light to both the
reflection light path and the transmission light path at one time
while both the boundary of the transmission region and the
reflection region of the reflection-transmission wheel traverses
the light path of the excitation light at one time.
3. The illumination light source device according to claim 2,
further comprising: a first drive part driving the
reflection-transmission member so that the transmission region and
the reflection region traverse the light path from the excitation
light source; a second drive part driving the fluorescent member;
and a position detector for boundary region detecting the boundary
region of the reflection-transmission member.
4. The illumination light source device according to claim 3,
further comprising: a light path junction element forming a
converged light path by converging the transmission light path and
the reflection light path, and converging a light flux led through
the transmission light path and a light flux led through the
reflection light path, and emitting converged light flux from the
illumination optical system.
5. The illumination light source device according to claim 4,
further comprising: an illumination light source emitting
illumination light of a different color from the excitation light
and the fluorescence to the converged light path.
6. The illumination light source device according to claim 5,
wherein: the reflection-transmission member includes the
reflection-transmission wheel, the fluorescent body member includes
the fluorescent wheel, the position detector for boundary region
includes the rotational angle position detector detecting the
rotational angle position of the reflection-transmission member,
the first drive member includes the drive part rotary driving the
reflection-transmission wheel, the second drive member includes the
drive part rotary driving the fluorescent wheel, and the
illumination optical system includes a first illumination optical
system comprising at least the excitation light source, the
reflection-transmission wheel, the light path junction element, and
the fluorescent wheel, and a second illumination optical system
comprising the light source.
7. A projection device comprising: the illumination light source
device according to claim 2, the illumination optical system
leading the illumination light emitted by the light path junction
element of the illumination light source device, and the projection
optical system projecting the images generated by the image
generator, wherein the control section generates the images
corresponding to the image data by use of the persistence of
vision, by dividing a time frame of image data, and controlling
on/off of the excitation light source corresponding to the image
data and controlling the image generator.
8. The projection device according to claim 7, wherein: the light
which have a color mixture of the color of the excitation light
source and the color of the illumination light source by the
principle of the additive color system by turning on the excitation
light source and the illumination light source in one time frame of
the image data is generated.
9. A method for control an illumination light source device
including an excitation light source forming a part of an
illumination optical system and emitting an emission light as an
optical wavelength; a reflection-transmission member forming a part
of an illumination optical system, being provided on a light path
of an excitation light source, and having a transmission region
transmitting the excitation light from the excitation light source
and a reflection region reflecting the excitation light from the
excitation light source; a fluorescent body member forming a part
of the illumination optical system, being provided on at least one
of a reflection light path of the excitation light reflected by the
reflection region and a transmission light path of the excitation
light transmitted the transmission region, and having the
fluorescent body emitting a fluorescence of a different color from
the excitation light when excited by the excitation light; a first
drive part member driving the reflection-transmission member so
that the transmission region and the reflection region periodically
traverse the light path of the excitation light; a second drive
part member driving the fluorescent body member; a rotational angle
position detector detecting a rotational angle position of the
reflection-transmission member; a control section controlling the
drive of the first drive part member and the second drive part
member and lighting-up of the excitation light source by use of a
detection result of the rotational angle position detector while a
boundary of the transmission region and the reflection region of
the reflection-transmission member is traverse the light path; and
a light path junction element forming the converged light path by
converging the transmission light path and the reflection light
path, the method comprising: converging a light flux led to the
light path junction element via the transmission light path and a
light flux led to the light path junction element via the
reflection light path and emitting by the illumination optical
system; detecting the rotational angle position of a
reflection-transmission wheel as the reflection-transmission
member; and controlling turning-on the excitation light source and
leading the excitation light to both the reflection light path and
the transmission light path at one time when both the boundary
region of the reflection region and the transmission region is
traverse by calculating the timing that the reflection-transmission
wheel traverse the light path of the light source at one time by
use of the detected result obtained by detecting.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a continuation of and claims the
benefit of priority under 35 U.S.C. .sctn.120 from U.S. application
Ser. No. 14/014,976, filed Aug. 30, 2013, which is based on and
claims priority under 35 U.S.C. .sctn.119 from Japanese Patent
Application Number 2012-200234, filed on Sep. 12, 2012, the entire
contents of both of which are hereby incorporated by reference
herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Present Invention
[0003] The present invention relates to an illumination light
source device, a projection device including the illumination light
source device and an improved method to control the projection
device.
[0004] 2. Description of the Related Art
[0005] Conventionally, light source devices employing a
high-intensity discharge lamp such as an extra high pressure
mercury lamp, as illumination light source devices for projection
devices (projector) projecting on-screen information of a personal
computer (hereinafter referred to as "PC") at conferences and
meetings have been known.
[0006] However, the discharge lamp takes a necessary time to emit
light stably after start of lighting, while enables high-brightness
at low cost.
[0007] Then, using a solid-state light-emitting element such as a
light-emitting diode or an organic light emitting diode of red (R),
green (G), and blue (B) as an alternate light source in place of
the discharge lamp has been proposed and put into practical
use.
[0008] By using the solid-state light-emitting element as a light
source for a projector, the projector can be started-up quickly and
can be configured to accomplish a care of environment.
[0009] Then, for example, Japanese Patent Application Publication
No. 2011-013316 (Patent Document 1) and Japanese Patent Application
Publication No. 2010-085745 (Patent Document 2) were developed to
solve the problem mentioned above.
[0010] As the illumination light source device employing the
solid-state light-emitting element, for example, it is widely known
that the skill to obtain a colored projection image by irradiating
a fluorescent body with laser light as a excitation light emitted
by a blue laser diode used as a first light source (excitation
light source), producing each light of R, G, and B by exiting the
fluorescent body, and controlling gradation each light of R, G, and
B by use of a light modulation device such as a DMD (Digital
Micromirror Device) (refer to Patent Document 1).
[0011] An illumination light source device according to Patent
Document 1 includes a luminescent plate (fluorescent wheel)
composed of a fluorescent body layer having a plurality of
segmented regions divided in a rotational direction and emitting
fluorescent light by receiving excitation light and a transmission
region transmitting the excitation light directly, a first light
source irradiating the fluorescent body with the excitation light,
a second light source emitting light of a different wavelength from
both of the excitation light and the fluorescence emitted by the
fluorescent body layer, a light collection optical system
collecting light emitted by the luminescent plate (fluorescent
wheel) and the light emitted by the second light source on the same
light-path, and an emission control section controlling the first
light source and the second light source.
[0012] The emission control section turns off the first light
source not to emit a light by the first light source and turn on
the second light source to emit a light by the second light source,
in order to prevent a color mixture at a boundary of adjacent
segmented regions.
[0013] The illumination light source device according to Patent
Document 1 can prevent the color mixture at the boundary of the
adjacent segmented regions by being configured to control to turn
off the first light source at the boundary. However, a time period
that the segmented region is irradiated with the excitation light
per unit time (one second) is constant regardless of its
revolutions of the fluorescent wheel per unit time (one second),
since the illumination light source device is configured so that
the fluorescent body of the fluorescent wheel is directly
irradiated with the excitation light. Therefore, a fluorescence
property of the fluorescent body may be deteriorated if a
mini-region of the segmented region remains irradiated with the
excitation light.
[0014] Now, there are being developed illumination light source
devices capable of keeping the fluorescent property of the
fluorescent body from deteriorating by enabling the fluorescent
body to change the time that being irradiated with the excitation
light in unit time by providing a reflection-transmission wheel as
a reflection-transmission member having a transmission region and
the reflection region on a light-path of the excitation light
emitted by the first light source, providing a fluorescent wheel as
a fluorescent member on at least one of a transmission light-path
made of the transmission region and a reflection light-path made of
the reflection region, and switching the light-path of the
excitation light between the transmission light-path and the
reflection light-path in an unit time (one second) of rotation of
the fluorescent wheel.
[0015] However, a color mixture occurs when the
reflection-transmission wheel is irradiated with the excitation
light while a boundary region between the reflection region and the
transmission region is passing through, even if the illumination
light source device is configured so that the
reflection-transmission wheel is provided on the light-path of the
excitation light emitted by the first light source.
[0016] Moreover, to prevent the color mixture, turning off an
excitation light source while the boundary region between the
reflection region and the transmission region is passing through
the light-path of the excitation light is one idea. But, such a
configuration to turn off the excitation light source decreases the
brightness.
SUMMARY OF THE INVENTION
[0017] The present invention is made in view of the above, and an
object thereof is to provide an illumination light source device
capable of further preventing the deterioration of a fluorescent
body, capable of improving a color reproducibility by obtaining a
lot of colors by use of the color mixture generated at a boundary
region between a transmission light-path and a reflection
light-path effectively and capable of improving brightness of an
image, a projector including the illumination light source device
and a method to control the projector.
[0018] An illumination light source device according to an
embodiment of the present invention includes a
reflection-transmission member provided on a light-path of an
excitation light from an excitation light source having a
transmission region transmits an excitation light as an optical
wavelength and a reflection region reflecting the excitation light
from the excitation light source and the transmission region and
the reflection region sequentially traverse the light-path of the
excitation light from the excitation light source, a fluorescent
body member provided on at least one of the reflection light-path
formed of the reflection region or the transmission light-path
formed of the transmission region having the fluorescent body
emitting fluorescence when excited by the excitation light, and a
control section turning-on the excitation light source while the
boundary of the transmission region and the reflection region of
the reflection-transmission wheel traverses the light-path of the
excitation light.
[0019] The illumination light source device according to the
present invention is configured so that the fluorescent body is
excited by the excitation light led by at least one of the
transmission region and the reflection region of the
reflection-transmission member, and a time that the fluorescent
body is irradiated with the excitation light in unit time can be
shortened, thus a deterioration of the fluorescent body can be
prevented.
[0020] Moreover, the illumination light source device according to
the present invention can improves the color reproducibility by
obtaining a wide variety of colors by use of the color mixture
occurred in the boundary region between the transmission light-path
and the reflection light-path effectively, and improves the
brightness of projection image, because of having a configuration
so that the excitation light source is turned-on while the boundary
between the transmission region and the reflection region on the
reflection-transmission member traverses the light-path of the
excitation light-path.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 illustrates an optical system of an illumination
light source device according to a first embodiment of the present
invention;
[0022] FIG. 2 is an enlarged plan view of a fluorescent wheel in
the illumination light source device shown in FIG. 1;
[0023] FIG. 3 is an enlarged plan view of a reflection-transmission
wheel in the illumination light source device shown in FIG. 1;
[0024] FIG. 4 illustrates a relationship between the
reflection-transmission wheel and a light-path of a first
illumination optical system in the illumination light source device
shown in FIG. 1;
[0025] FIG. 5 illustrates an example of a configuration of a
projection device according to a second embodiment of the present
invention using the illumination light source device shown in FIG.
1;
[0026] FIG. 6 illustrates an example of a relationship among a
color of light irradiating with an image generator shown in FIG. 5,
on/off timing of each light source, and reflection/transmission of
the reflection-transmission wheel, in relationship to a frame of
images;
[0027] FIG. 7 illustrates a relationship between a rotational angle
position of the reflection-transmission wheel shown in FIG. 1 and
the light-path of the first illumination optical system shown in
FIG. 1;
[0028] FIG. 8 is a block diagram illustrating the configuration of
a control section shown in FIG. 5;
[0029] FIG. 9A illustrates a state that one boundary of the
reflection-transmission wheel is overlaps with one of tangent to a
spot region when the boundary traverses the spot region;
[0030] FIG. 9B illustrates a state in that one boundary of the
reflection-transmission wheel overlaps with other tangent to a spot
region when the boundary traverses the spot region;
[0031] FIG. 10 illustrates a relationship among a rotational phase
of the reflection-transmission wheel, a lighting of the second
light source, and intensity of illumination light, wherein (a)
illustrates the rotational phase of the reflection-transmission
wheel, (b) illustrates on-state of the second light source, and (c)
illustrates a relationship between intensity of excitation light at
a wavelength .lamda.A and intensity of fluorescence at a wavelength
.lamda.B corresponding to the rotational phase (a);
[0032] FIGS. 11A-11D illustrate variations of angular range of the
spot region wherein FIGS. 11A and 11B are the same as FIGS. 9A and
9B and reposted for reference, and FIGS. 11C and 11D are FIGS. 11A
and 11B wherein the angular range is doubled;
[0033] FIG. 12 illustrates an example of a relationship of
intensity between the wheel-rotational phase of the
reflection-transmission wheel and the illumination wherein (a) and
(c) are same to FIG. 10(a)(c) and reposted for reference, (b)
illustrates the wheel-rotational phase corresponding to FIGS. 11C,
and 11D, and (d) illustrates a relationship between the intensity
of the excitation light at the wavelength .lamda.A and the
intensity of fluorescence at the wavelength .lamda.B corresponding
to the wheel-rotational phase shown in FIG. 12(b);
[0034] FIGS. 13A-13E illustrate other examples of the
reflection-transmission wheel wherein FIGS. 13A and 13B are the
same as FIGS. 9A and 9B and reposted for reference, and FIGS. 13C,
13D, and 13E illustrate a state that the reflection region is split
into a beam-splitter region and the total reflection region,
wherein FIG. 13C illustrates a state that forward boundary of the
beam-splitter region in rotational direction is overlapped with one
of the tangent, FIG. 13D illustrates a state that the boundary
between the beam-splitter region and the total reflection region is
overlapped with one of the tangent, FIG. 13E illustrates a state
that forward boundary of the total reflection region in rotational
direction is overlapped with other tangent;
[0035] FIG. 14 illustrates an example of a relationship of
intensity between the wheel-rotational phase of the
reflection-transmission wheel and the illumination wherein (a) is
same to FIG. 12(a) and reposted for reference, (b) illustrates the
wheel-rotational phase when the boundary between the transmission
region and the beam-splitter region on the reflection-transmission
wheel shown in FIGS. 13C, 13D, and 13E is passing through the spot
region, (c) illustrates the wheel-rotational phase when the
boundary between the beam-splitter region and the total reflection
region on the reflection-transmission wheel shown in FIGS. 13C,
13D, and 13E is passing through the spot region, (d) is same to
FIG. 12(c) and reposted for reference, (e) illustrates a
relationship between the intensity of excitation light at the
wavelength .lamda.A and the intensity of fluorescence at the
wavelength .lamda.B corresponding to the rotational phase of the
reflection-transmission wheel shown in FIG. 12(b);
[0036] FIGS. 15A and 15B illustrate white-light generation wherein
FIGS. 15A and 15B are the same as FIGS. 9A and 9B and reposted for
reference;
[0037] FIG. 16 illustrates white-light generation wherein (a) is
same to FIG. 10(a) and reposted for reference, (b) illustrates a
driving state of the light source 2, (c) illustrates a driving
state of the light source 3, and (d) illustrates a generated
white-light;
[0038] FIG. 17 is a pattern diagram illustrates an example of a
sensor detecting the rotational angle position of
reflection-transmission wheel;
[0039] FIG. 18 is a pattern diagram illustrates a relationship
between the rotational angle position and the gravity acceleration
of an acceleration sensor;
[0040] FIG. 19 illustrates an optical system of a light source
device according to a third embodiment of the present
invention;
[0041] FIG. 20 illustrates an example of a relationship among a
color of light which irradiates an image generator by use of the
illumination light source shown in FIG. 19, on/off timing of each
light source, and reflection/transmission of the
reflection-transmission wheel, in relationship to a frame of
images;
[0042] FIG. 21 illustrates another example of a relationship among
colors of light irradiating an image generator by use of the
illumination light source shown in FIG. 19, on/off timing of each
light source, and reflection /transmission of the
reflection-transmission wheel, in relationship to a frame of
images;
[0043] FIG. 22 illustrates an optical system of a light source
device according to a fourth embodiment of the present
invention;
[0044] FIG. 23 is a partially enlarged view of the first
illumination optical system shown in FIG. 22;
[0045] FIG. 24 illustrates the spot region generated on the
reflection-transmission wheel by the first illumination optical
system shown in FIG. 22;
[0046] FIG. 25 illustrates an optical system of a light source
device according to a fifth embodiment of the present
invention;
[0047] FIG. 26 is a plan view of the reflection-transmission wheel
shown in FIG. 25;
[0048] FIG. 27 is a plan view of a fluorescent wheel shown in FIG.
25;
[0049] FIG. 28 illustrates an example of a relationship among a
color of light which irradiates the image generator by use of the
illumination light source device shown in FIG. 25, on/off timing of
each light source, and reflection/transmission of the
reflection-transmission wheel, in relationship to a frame of
images;
[0050] FIG. 29A illustrates the rotational angle position of the
reflection-transmission wheel shown in FIG. 26 wherein one boundary
is angled at 45 degrees as a reference position;
[0051] FIG. 29B illustrates the rotational angle position of the
reflection-transmission wheel shown in FIG. 26 wherein one boundary
is angled at 135 degrees;
[0052] FIG. 29C illustrates the rotational angle position of the
reflection-transmission wheel shown in FIG. 26 wherein one boundary
is angled at 150 degrees;
[0053] FIG. 29D illustrates the rotational angle position of the
reflection-transmission wheel shown in FIG. 26 wherein one boundary
is angled at 165 degrees;
[0054] FIG. 29E illustrates the rotational angle position of the
reflection-transmission wheel shown in FIG. 26 wherein one boundary
is angled at 195 degrees;
[0055] FIG. 29F illustrates the rotational angle position of the
reflection-transmission wheel shown in FIG. 26 wherein one boundary
is angled at 210 degrees;
[0056] FIG. 29G illustrates the rotational angle position of the
reflection-transmission wheel shown in FIG. 26 wherein one boundary
is angled at 225 degrees;
[0057] FIG. 30A illustrates the rotational angle position of the
fluorescent wheel shown in FIG. 27 wherein one boundary is angled
at 0 as a reference position;
[0058] FIG. 30B illustrates again the rotational angle position of
the fluorescent wheel shown in FIG. 27 wherein one boundary is
angled at 0 degree;
[0059] FIG. 30C illustrates the rotational angle position of the
fluorescent wheel shown in FIG. 27 wherein one boundary is angled
at 60 degrees;
[0060] FIG. 30D illustrates the rotational angle position of the
fluorescent wheel shown in FIG. 27 wherein one boundary is angled
at 120 degrees;
[0061] FIG. 30E illustrates the rotational angle position of the
fluorescent wheel shown in FIG. 27 wherein one boundary is angled
at 240 degrees;
[0062] FIG. 30F illustrates the rotational angle position of the
fluorescent wheel shown in FIG. 27 wherein one boundary is angled
at 300 degrees;
[0063] FIG. 30G illustrates the rotational angle position of the
fluorescent wheel shown in FIG. 27 wherein one boundary is angled
at 60 degrees;
[0064] FIG. 31 illustrates a relationship among the rotational
angle position of each wheel, the rotational phase of each wheels,
and a color of light which irradiates the image generator when the
light source 2 is turned on, with using the reflection-transmission
wheel shown in FIG. 26 and the fluorescent wheel shown in FIG.
27.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0065] Embodiments of the present invention will be described
hereinafter in detail with reference to the accompanying
drawings.
First Embodiment
[0066] FIG. 1 illustrates an optical system of a light source
device according to a first embodiment of the present invention
wherein numeral 1 shows an illumination optical system.
(Schematic Configuration of the Illumination Optical System 1)
[0067] In this case, the illumination optical system has two
illumination light sources (hereinafter referred to as "light
sources") 2, 3. The light source 2 forms a part of a first
illumination optical system 1A, and the light source 3 forms a part
of a second illumination optical system 1B.
[0068] The first illumination optical system 1A is schematically
composed of a coupling lens 2a as a first optical element, a
reflection-transmission wheel 2b as a reflection-transmission
member, a total reflection mirror 2c, and a fluorescent wheel 2e as
a fluorescent body member.
[0069] The reflection-transmission wheel 2b is arranged on a
light-path of the light source 2. The light-path of the light
source 2 is split into a transmission light-path and a reflection
light-path by a transmission region and a reflection region of the
reflection-transmission wheel 2b (it will be described later).
[0070] The second illumination optical system 1B is schematically
composed of a coupling lens 3a, a dichroic mirror 3b, and a
dichroic mirror 3c. The dichroic mirror 3b and the dichroic mirror
3c are shared by the first illumination optical system 1A.
[0071] The fluorescent wheel 2e is formed of a disk-shaped
substrate 2g and a fluorescent body 2h, and arranged on the
transmission light-path formed by the transmission region of the
reflection-transmission wheel 2b. A collecting element 2i is
provided on a front side of the fluorescent wheel 2a.
(Detailed Configuration of the First Illumination Optical System
1A)
[0072] The light source 2 is a solid-state light-emitting element
emitting an excitation light of a short wavelength. For example, a
blue laser diode emitting a blue laser light as a visible light is
used as the light source 2. Note that, a light-emitting diode
emitting a blue light can be used in place of the blue laser diode.
Here, the light source 2 emits light in a wavelength .lamda.A (400
nm<.lamda.A<450 nm).
[0073] FIG. 2 illustrates the disk-shaped substrate 2g of the
fluorescent wheel 2e viewed from the side where the fluorescent
body 2h is formed. The disk-shaped substrate 2g is formed of a
reflection material, and the fluorescent body 2h is formed into a
ring shape. The disk-shaped substrate 2g is rotationally driven by
a drive part 2f as a second drive member on a rotating shaft
2j.
[0074] The light in the wavelength .lamda.A is reflected by the
total reflection mirror 2c after transmitting the transmission
region of the reflection-transmission wheel 2b, collected by the
collecting element 2j, and irradiates the fluorescent wheel 2e.
[0075] At that time, a mini-region 2hm of the fluorescent body 2h
is irradiated with the light in the wavelength .lamda.A in a spot
as shown in FIG. 2. If the same mini-region 2hm of the fluorescent
body 2h remains irradiated by the light in the wavelength .lamda.A,
the fluorescent body 2h may become so called a "burnt" state, and a
property of the fluorescent body 2h may be deteriorated or
broken.
[0076] However, in the configuration according to the first
embodiment, it is prevented that the same mini-region 2hm of the
fluorescent body 2h continues to be irradiated with the light
energy in the wavelength .lamda.A and the property of the
fluorescent body 2h is deteriorated since the disk-shaped substrate
2g is constantly rotationally driven on a rotating shaft 2j and the
mini-region of the fluorescent body 2hm irradiated with the light
in the wavelength .lamda.A is temporally-shifted. Note that, a
rotating speed of the disk-shaped substrate 2g is not limited in
particular.
[0077] Note that, the first embodiment is configured to prevent
that the same mini-region of a fluorescent body 2hm continues to be
irradiated by the light in the wavelength .lamda.A by rotating the
disk-shaped substrate 2g, but not limited to this configuration.
For example, the mini-region 2hm of the fluorescent body 2h
irradiated with the light in the wavelength .lamda.A can be
temporally-shifted by employing a rectangle-shaped substrate (not
shown) in place of the disk-shaped substrate 2g, forming the
fluorescent body 2h extending in a longitudinal direction of the
rectangle-shaped substrate, and periodically reciprocating the
rectangle-shaped substrate in a longitudinal direction and in a
direction perpendicular to the light in the wavelength
.lamda.A.
[0078] The fluorescent body 2h is excited by the light in the
wavelength .lamda.A and emits fluorescence in a wavelength .lamda.B
longer than the wavelength .lamda.A as shown in FIG. 1. For
example, a range of the wavelength .lamda.B is within 495
nm<.lamda.B<570 nm which is a green fluorescence.
[0079] The fluorescence in the wavelength .lamda.B is reflected by
disk-shaped substrate 2g, collected by a collecting element, and
emitted from the fluorescent wheel 2e.
[0080] The reflection-transmission wheel 2b is rotationally driven
on a rotating shaft 2m by a drive part 2n as a first drive member.
The reflection-transmission wheel 2b has a fan-shaped reflection
region 2p bounded by two radial region boundary 2r.sub.1, 2r.sub.2
and an arc 2r.sub.5 as shown in FIG. 3.
[0081] The reflection region 2p has a function that totally
reflects the light in the wavelength .lamda.A. The rest of the
reflection region 2p of the reflection-transmission wheel 2b is a
transmission region 2q totally transmitting the light in the
wavelength .lamda.A.
[0082] In the first embodiment, the reflection-transmission wheel
2b is formed of a transparent disk with the fan-shaped reflection
region 2p, that is to say the rest of the reflection region 2p is
the transmission region 2q. But, if the reflection-transmission
wheel 2b is formed by the fan-shaped reflection region 2p itself, a
material can be saved, and the production cost for a device can be
reduced.
[0083] Note that, in the first embodiment, an angular range of the
fan-shaped reflection region 2p, a pivot point thereof is the
rotating shaft 2m, is 90 degrees, but a dimension of the reflection
region 2p is not limited to this.
[0084] Moreover, in the first embodiment, the reflection region 2p
and the transmission region 2q are switched by rotating the
reflection-transmission wheel 2b, but the reflection region 2p and
the transmission region 2q can be switched by reciprocating the
rectangle-shaped substrate.
[0085] The reflection-transmission wheel 2b is arranged obliquely
relative to an optical axis O1 of the light-path of the first
illumination optical system 1A. In the first embodiment, the
reflection-transmission wheel 2b is arranged at 45 degrees relative
to the optical axis O1, but it is not limited to this angle if the
light-path of the excitation light in the wavelength .lamda.A can
be switched.
[0086] Furthermore, the incidence of speckle pattern can be
decreased by using the diffuser panel in place of the transmission
region 2q of the reflection-transmission wheel 2b.
[0087] The reflection-transmission wheel 2b is appropriately
rotated in synchronization with the image data, and the
transmission light-path and the reflection light-path are
appropriately selected corresponding to the color of the image data
to be formed. Here, for example, the reflection-transmission wheel
2b rotates 30 times every second, and rotates once or twice every
one frame (e.g., 1/30 seconds).
[0088] Namely, the light in the wavelength .lamda.A emitted from
the light source 2 is led to the reflection-transmission wheel 2b
via the coupling lens 2a. Next, the light in the wavelength
.lamda.A is reflected by the reflection region 2p of the
reflection-transmission wheel 2b and led to the dichroic mirror 3b
when the reflection region 2p is placed at the light-path of the
first illumination optical system 1A, on the other hand, the light
in the wavelength .lamda.A is led to the total reflection mirror 2c
through the transmission region 2q of the reflection-transmission
wheel 2b when the transmission region 2q is placed at the
light-path of the first illumination optical system 1A.
(Detailed Configuration of the Second Illumination Optical System
1B)
[0089] The light source 3 is the solid-state light-emitting element
emitting the light in a wavelength .lamda.C longer than the
wavelength .lamda.B. For example, the range of the wavelength
.lamda.C is within 620 nm<.lamda.C<750 nm which is a red
light. Note that, the numeral O2 refers to the optical axis of the
second illumination optical system 1B.
[0090] The dichroic mirror 3b has a function that reflects the
light in the wavelength .lamda.A and transmits the wavelength
.lamda.C. The dichroic mirror 3c has the function that transmits
the light in the wavelength .lamda.A and a light in the wavelength
.lamda.C and reflects a light in the wavelength .lamda.B.
(Detailed Light-Path Formed of the Reflection-Transmission Wheel
2b, the Dichroic Mirror 3b, and the Dichroic Mirror 3c)
[0091] When the reflection region 2p of the reflection-transmission
wheel 2b is placed at the light-path of the first illumination
optical system 1A, the light in the wavelength .lamda.A is
reflected by the reflection region 2p, lead to and reflected by the
dichroic mirror 3b, and emitted as a blue light from the first
illumination optical system 1 through the dichroic mirror 3c.
[0092] When the transmission region 2q of the
reflection-transmission wheel 2b is placed at the light-path of the
first illumination optical system 1A, the light in the wavelength
.lamda.A transmits the transmission region 2q, and is reflected by
the total reflection mirror 2c, and led to the fluorescent wheel 2e
through the dichroic mirror 3c.
[0093] The light in the wavelength .lamda.A is collected by the
collecting element 2i and irradiates the miniregion of the
fluorescent body 2hm (see FIG. 2) of the fluorescent body 2h, then
the fluorescent body 2hm is excited and emits the light in the
wavelength .lamda.B.
[0094] The light in the wavelength .lamda.A and the light in the
wavelength .lamda.B are reflected by the disk-shaped substrate 2g,
collected by the collecting element 2i, and led to the dichroic
mirror 3c. The light in the wavelength .lamda.A traverses the
dichroic mirror 3c, on the other hand, the light in the wavelength
.lamda.B is reflected by the dichroic mirror 3c and emitted as a
green light from the first illumination optical system 1.
[0095] The light in the wavelength .lamda.C is led to the dichroic
mirror 3b through the coupling lens 3a, and emitted as the red
light from the first illumination optical system 1 through the
dichroic mirror 3b and the dichroic mirror 3c.
[0096] The dichroic mirror 3c functions as a light-path junction
element forming the converged light-path by converging on the
transmission light-path and the reflection light-path which split
by the reflection-transmission wheel 2b.
[0097] According to the first embodiment, the light-path of the
excitation light is split into the transmission light-path and the
reflection light-path by providing the reflection-transmission
wheel 2b, and a time that the fluorescent body is irradiated with
the excitation light in unit time (one second) can be shortened,
thus a deterioration of the fluorescence property of the
fluorescent body can be prevented.
(A Problem of the Color Mixture at the Boundary Between the
Reflection Region 2p and the Transmission Region 2q of the
Reflection-Transmission Wheel 2b)
[0098] The light in the wavelength .lamda.A traverses the
reflection-transmission wheel 2b with given dimension as shown in
FIG. 4. That is to say, the reflection-transmission wheel 2b is
irradiated with the light in the wavelength .lamda.A as a spot. In
FIG. 4, reference numeral 2s refers to the spot region (dimension
of the light-path) that the reflection-transmission wheel 2b is
irradiated with the light in the wavelength .lamda.A.
[0099] When the light in the wavelength .lamda.A irradiates a
boundary region of the reflection-transmission wheel 2b, the light
in the wavelength .lamda.A (blue) reflected by the reflection
region 2p is reflected by the dichroic mirror 3b and emitted from
the first illumination optical system 1. On the other hand, the
light in the wavelength .lamda.A traversed the transmission region
2q is reflected by the total reflection mirror 2c, led to the
fluorescent wheel 2e through the dichroic mirror 3c, excites the
fluorescent body 2h of the fluorescent wheel 2e, and the green
fluorescence (the light in the wavelength .lamda.B) from the
fluorescent body 2h is reflected by the dichroic mirror 3c and
emitted from the first illumination optical system 1.
[0100] Thereby, the light which is a mixture of blue light and
green right is emitted from the first illumination optical system
1. Therefore, color mixture is occurred when region boundary
2r.sub.1, 2r.sub.2 between the reflection region 2p and the
transmission region 2q of the reflection-transmission wheel 2b
traverse the light-path of the first illumination optical system
1A. For example, an image of cyan is periodically produced when an
image of blue or green is demanded, and color purity is
impaired.
[0101] If the light source 2 is turned off in order to prevent the
occurrence of the color mixture when the boundary region of the
reflection-transmission wheel 2b traverses the light-path (spot
region), the brightness is decreased since the illumination light
from the light source 2 is fail to efficiently utilized.
[0102] Then, in the first embodiment, the light source 2 is turned
on positively regardless of the image data and the light source 3
is also turned on in synchronization with the light source 2 when
the region boundary 2r1, 2r2 between the reflection region 2p and
the transmission region 2 of the reflection-transmission wheel 2b
traverse the light-path of the first illumination optical system
1A.
[0103] As the result, decreasing of the brightness can be prevented
and the color reproducibility can be improved when the region
boundary 2r.sub.1, 2r.sub.2 between the reflection region 2p and
the transmission region 2q of the reflection-transmission wheel 2b
traverses the light-path. The controlling of the lighting-up will
hereinafter be described in detail.
Second Embodiment
[0104] FIG. 5 illustrates a second embodiment of the configuration
of a projection device 10 using the illumination optical system 1
according to the first embodiment. In FIG. 5, elements which are
same as in the first embodiment are provided by attaching same
numerals thereto and their detailed descriptions are omitted.
[0105] The projection device 10 has a control section 11
controlling the illumination optical system 1, a collecting element
12, an integrator 13, a collecting element 14, a reflection mirror
15, an image generator 16, and a projection lens 17 provided on the
light-path forward of the illumination optical system 1. The
collecting element 12, the integrator 13, the collecting element
14, the reflection mirror 15, the image generator 16, and the
projection lens 17 forms a projection optical system.
[0106] The light flux in the wavelength .lamda.A, .lamda.B, and
.lamda.,C are collected by the collecting element 12, diffused
uniformly by the integrator 13 to remove an uneven light intensity
and irradiates the image generator 16 through the collecting
element 14 and the reflection mirror 15. Hereinafter, the
configuration and the function of the image generator 16 will be
described. The control section 11 will be described later.
(Configuration and Function of the Image Generator 16)
[0107] In the image generator 16, image generation data are
inputted. The image generator 16 is formed of, for example, a DMD
(Digital Micromirror Device) which is publicly known.
[0108] The DMD has pixel-based micromirrors. The each angle of the
micromirrors is two-position controlled, and the micromirror can
control the gradation by controlling the repeating time interval of
the two-position control.
[0109] Then, the full-color images are generated by use of
persistence of vision by irradiating each color of RGB, R (red:
wavelength .lamda.C), G (green: wavelength .lamda.B), and B (blue:
wavelength .lamda.A) in a time frame of the image by switching,
driving the image generator 16 by micromirror drive signal based on
the pixel-based image generation data in synchronization with the
timing of the irradiating of the each color of RGB.
(Configuration and Function of the Control Section 11)
[0110] The control section 11 has a CPU (Central Processing Unit),
a ROM (Read Only Memory), and a RAM (Random Access Memory).
[0111] The control section 11 totally controls a performance of the
projection device 10 in accordance with the program memorized in
advance by use of the RAM as a working memory.
[0112] Furthermore, the control section 11 has an interface (not
shown) to external information equipment and can road image data
from, for example, a personal computer.
[0113] And the control section 11 processes the loaded image data,
and generates the image generation data adapted to drive the image
generator 16.
[0114] The image generation data is inputted to a drive signal
generator 18, the drive signal generator 18 generates a drive
signal based on the image generation data, and the drive signal
outputted to the image generator 16.
[0115] Moreover, the control section 11 controls the lighting-up of
the light sources 2, 3, and the rotation of the drive parts 2f,
2n.
[0116] Hereinafter, an embodiment of controlling by the control
section 11 will be described with reference to FIG. 6.
[0117] FIG. 6(a) illustrates a formation time T of the Nth frame of
images (e.g., T= 1/30 sec) corresponding to the rotational angle
position of the reflection-transmission wheel 2b, for example, by
dividing the time T into five time period. In FIG. 6, the time
periods are indicated by the numeral a to e, and the light fluxes
irradiates each time periods a to e are supposed to be Rn (red), Gn
(green), Bn (blue), Yn (yellow), Mn (magenta).
[0118] FIG. 6(b) illustrates on/off timing of the light sources 2,
3, and reflection/transmission timing of the
reflection-transmission wheel to each time periods a to e. In the
time period a, i.e. the rotational angle position of the region
boundary 2r.sub.2 is within the range of 0 to 90 degrees, the
light-path of the first illumination optical system 1A is in the
transmission region 2q, when the light source 2 is turned off and
the light source 3 is turned on by the control section 11, the
image generator 16 is irradiated with the red light (Rn) by the
second illumination optical system 1B.
[0119] In the time period b, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 90 to 180
degrees, when the light source 2 is turned on and the light source
3 is turned off by the control section 11, and the control section
11 controls the rotational angle position of the
reflection-transmission wheel 2b is controlled by the control
section 11 so that the transmission region 2q is in the light-path
of the first illumination optical system 1A the image generator 16
is irradiated with the green light (Gn).
[0120] In the time period c, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 180 to 225
degrees, when the light source 2 is turned on and the light source
3 is turned off by the control section 11, and the rotational angle
position of the reflection-transmission wheel 2b is controlled by
the control section 11 so that the reflection region 2p is in the
light-path of the first illumination optical system 1A in
synchronization with the lighting timing of the light sources, the
image generator 16 is irradiated with the blue light (Bn).
[0121] In the time period d, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 225 to 270
degrees, when the light source 2, 3 are turned on at the same time
by the control section 11, and the rotational angle position of the
reflection-transmission wheel 2b is controlled by the control
section 11 so that the reflection region 2p is in the light-path of
the first illumination optical system 1A , the image generator 16
is irradiated with the magenta light (Mn) by the principle of the
additive color system since the blue light (Bn) and the red light
(Rn) are emitted from the illumination optical system 1 at the same
time.
[0122] In the time period e, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 270 to 360
degrees, when the light source 2, 3 are turned on at the same time
by the control section 11, and the rotational angle position of the
reflection-transmission wheel 2b is controlled by the control
section 11 so that the transmission region 2q is in the light-path
of the first illumination optical system 1A, the image generator 16
is irradiated with the yellow light (Yn) by the principle of the
additive color system since the green light (Gn) and the red light
(Rn) are emitted from the illumination optical system 1 at the same
time.
[0123] Thus, according to the second embodiment, the full-color
images can be generated and the gradation control can be achieved
by two-position controlling of the irradiation timing of each light
of red, green, blue, magenta, and yellow and the angle of each DMD
by use of the persistence of vision, since the image generator 16
can be irradiated with the each colored light of red, green, blue,
magenta, and yellow, within each time period, I.e. one of a time
frame divided by five.
[0124] Note that, in this embodiment, the dimension of the
light-path of the first illumination optical system 1A, i.e. the
dimension of the spot region, is ignored, and only the rotational
angle position of the region boundary 2r.sub.2 is described for the
convenience of description. However, it is possible to relate 60
degrees of the rotation angular range of the
reflection-transmission wheel 2b to each color, and to use rest of
60-digree angle where the color mixture is generates, i.e. both
side of 30 degrees straddling the boundary, for white light with
both the light source 2 and 3 turned on.
[0125] Furthermore, on/off timing of the light source 2, 3 and the
color of light irradiating the image generator 16 are illustrated
in FIG. 4 for ease of comprehension.
[0126] According to the second embodiment, the reflection
light-path from the reflection region 2p of the
reflection-transmission wheel 2b returns the same route since the
disk-shaped substrate 2g of the fluorescent wheel 2e is made of a
reflection material. Therefore, the illumination optical system 1
can be downsized.
(Detailed Description of the Controlling of the Rotational Angle
Position of the Reflection-Transmission Wheel 2b by the Control
Section 11)
[0127] The reflection-transmission wheel 2b is rotated on the
rotating shaft 2m so as to traverse the light-path from the first
illumination optical system 1A as shown in FIG. 7.
[0128] Note that, a spot region 2s, which has the same dimension to
the light-path of the illumination optical system, is indicated in
FIG. 7 by dashed line in place of the light-path of the
illumination optical system 1 for the convenience of
description.
[0129] The region boundary 2r.sub.1, 2r.sub.2 between the
reflection region 2p and the transmission region 2q traverses the
spot region 2s once every 1 round.
[0130] Furthermore, the rotational angle positions in every
rotation of the reflection-transmission wheel 2b are indicated in
FIG. 7 with appropriate angles in clockwise direction from
horizontal line (0 degrees) as a reference position, for the
convenience of description.
[0131] In FIG. 7, two tangent lines extending in a radial direction
from the center of the rotating shaft 2m and circumscribing on a
circle of the spot region 2s are indicated as the reference numbers
2r.sub.1', 2r.sub.2'.
[0132] The angle .theta. formed by the two tangent lines 2r.sub.1',
2r.sub.2' is dependent on a radius of the spot region 2s and the
distance from the center of the rotating shaft 2m to the center of
the spot region 2s (the optical axis O1).
[0133] Here, the angle .theta. is, for example, 30 degrees. When
one of the region boundary 2r.sub.1 or the region boundary 2r.sub.2
is in a fun-shaped region a enclosed by the two tangent lines
2r.sub.1', 2r.sub.2' and an arc and the light source 2 is turned
on, the light in the wavelength .lamda.A (blue) transmits the
transmission region 2q and is reflected by the reflection region
2p.
[0134] Thus, the light with the color mixture of the light in the
wavelength .lamda.A (blue) reflected by the reflection region 2p
and the dichroic mirror 3b, and the light in the wavelength
.lamda.B (green) generated by being reflected by total reflection
mirror 2c after passing through the transmission region 2q and led
to the fluorescent wheel 2e, can be obtained.
(Description of a Block Diagram of a Specific Control by the
Control Section 11)
[0135] FIG. 8 is a block diagram illustrating the configuration of
a control section. As noted earlier, the control section 11 has the
CPU, the ROM, and the RAM, and totally controls the performance of
the projection device 10 in accordance with the program memorized
in advance by use of the RAM as the working memory.
[0136] The control section 11 has a wheel phase signal setup
circuit 11a, an LD driver 11b, an LD drive circuit 11c, and an
image generator control circuit 11d besides the circuit elements
described above. The wheel phase signal setup circuit 11a sets up
the wheel phase by obtaining the rotational angle position by the
sensor Se described below.
[0137] The control section 11 switches the wheel phase from "1" to
"0" as shown in FIG. 10 by the wheel phase signal setup circuit 11a
when the region boundary 2r.sub.1 (or region boundary 2r.sub.2)
overlaps with one of a tangent line 2r.sub.2' circumscribed on a
circle of the spot region 2s as shown in FIG. 9A, and switches the
wheel phase from "0" to "1" as shown in FIG. 10 by the wheel phase
signal setup circuit 11a when the region boundary 2r, (or region
boundary 2r.sub.2) overlaps with another tangent line 2r.sub.1'
circumscribed on the circle of the spot region 2s as shown in FIG.
9B.
[0138] The wheel phase signal setup circuit 11a turns on the LD
drive circuit 11c and the image generator control circuit 11d at
least while the time t1, the time from the point that the wheel
phase is changed from "1" to "0" to the point that the wheel phase
is changed from "0" to "1".
[0139] By the LD driver 11b, the LD drive circuit 11c is driven and
at least the light source 2 is turned on while the time t1 from the
point that the wheel phase is changed from "1" to "0" to the point
that the wheel phase is changed from "0" to "1" as shown in FIG.
10.
[0140] Furthermore, the image generator control circuit 11d turns
on the image generator 16 while the wheel phase is in "0". Thereby,
a cyan light generated by mixture of blue light and green light is
projected to the screen.
[0141] For example, as shown in FIG. 10(c) simplistically, when the
light source 2 is turned on, the green fluorescence of constant
intensity is emitted from the projection device 10 until just
before that the region boundary 2r.sub.1 is circumscribed on the
spot region 2s. Then, the green fluorescence is decreased while the
blue excitation light is increased by the region boundary 2r.sub.1
passing through the spot region 2s, and when the time t1 is
elapsed, becomes the blue light of constant intensity.
[0142] Note that, the angle .theta. is described as 30 degrees in
this embodiment, but not limited to the angle .theta.=30, since the
angle .theta. is dependent on the radius of the spot region 2s and
the distance from the center of the rotating shaft 2m to the center
of the spot region 2s (the optical axis O1).
(An Example of the Coordination of a Creation Time of the Cyan
Light)
[0143] FIGS. 11, 12 illustrate the coordination of a creation time
of the cyan light by adjusting the dimension of the spot region
2s.
[0144] FIGS. 11A, B are same to FIG. 9A, B and reposted for
reference, and FIG. 11C,D illustrate the angle .theta. (=30
degrees) formed by the tangent lines 2r.sub.1', 2r.sub.2' on the
spot region 2s are changed to 2.theta. (=60 degrees).
[0145] Thus, when the angle .theta. formed by the tangent lines
2r.sub.1', 2r.sub.2'of the spot region 2s is doubled, and it is
assumed that the number of rotations of the reflection-transmission
wheel 2b is constant, the time t1, where the wheel phase is "0",
can be doubled as shown in FIG. 12(b) compared to FIG. 12(a).
Thereby, the time t1 to emits the cyan light as shown in FIG. 12(d)
compared to FIG. 12(c).
[0146] The dimension of the spot region 2s can be adjusted by
moving the coupling lens 2a back and forth in an optical axis
direction by use of a drive mechanism, or adjusting the rotating
speed of the reflection-transmission wheel 2b. Note that, these
operations can be operated manually by button with watching the
projected images.
(Another Example of the Coordination of a Creation Time of the Cyan
Light)
[0147] FIGS. 13, 14 illustrate another example of the coordination
of a creation time of the cyan light by adjusting the dimension of
the reflection region 2p.
[0148] FIGS. 13A, B are same to FIGS. 9A, B and reposted for
reference, and FIG. 13C to (e) illustrate the
reflection-transmission wheel 2b wherein 1/3 angle region in the
forward part of the reflection region 2p in rotational direction of
the reflection-transmission wheel 2b is a semi-transmissive region
2p.sub.0 (beam splitter region), while 2/3 angle region the
backward part in rotational direction is a total reflection region
2p.sub.1.
[0149] The reflection rate of the total reflection region 2p.sub.1
is 100%, and the reflection rate of the semi-transmissive region is
settable conveniently. In this example, as shown in FIG. 13C, the
cyan light is generated by the green fluorescence generated by the
excitation light transmitted the semi-transmissive region 2p.sub.0
and the blue excitation light reflected by the semi-transmissive
region 2p.sub.0 while the time from the point that the region
boundary 2r.sub.1 of the semi-transmissive region 2p.sub.0 contacts
the tangent line 2r.sub.2' to the point that the region boundary
2pr.sub.1 between the semi-transmissive region 2p.sub.0 and the
total reflection region 2p.sub.1 contacts the tangent line
2r.sub.2'.
[0150] As shown in FIG. 13D, the cyan light is generated by the
green fluorescence generated by the excitation light transmitted
the semi-transmissive region 2p.sub.0 and the blue excitation light
reflected by the total reflection region 2p.sub.1 until the region
boundary 2pr.sub.1 between the semi-transmissive region 2p.sub.0
and the total reflection region 2p.sub.1 contacts the tangent line
2r.sub.1'.
[0151] Next, the blue excitation light is emitted since the
excitation light is reflected by the total reflection region
2p.sub.1 until the region boundary 2r.sub.2 of the total reflection
region 2p.sub.1 (the region boundary of the reflection region 2p)
contacts the tangent line 2r.sub.2'. Then, when the region boundary
2r.sub.2 of the total reflection region 2p.sub.1 (the region
boundary of the reflection region 2p) contacts the tangent line
2r.sub.2', the cyan light is generated by the excitation light
reflected by the reflection region 2p and the green light generated
by the excitation light transmits the transmission region 2q.
[0152] Therefore, as shown in FIG. 14, the creation time t1 of the
cyan C can be adjusted by forming the beam splitter region 2p.sub.0
on the reflection region 2p.sub.1.
(Generation of the White Light by the Light Source 2 and the Light
Source 3)
[0153] In the embodiments described above, it is described that to
generate the cyan light while the region boundary 2r.sub.1, 2r2
traverses the spot region 2s. However, if he light source device is
configured to control to turn on both the light source 2 and the
light source 3 at the same time, the light source device can emits
tricolored light of blue, green, and red at the same time, i.e.
white light, and highly intensity images can be obtained as shown
in FIG. 15, FIG. 16.
[0154] FIGS. 15A, B are same to FIGS. 9A, B and reposted for
reference, and FIG. 16(a) to (d) simplistically illustrate that the
white light W can be obtained in the time between yellow Y and
magenta M.
(An Example of a Sensor Detecting the Rotational Angle Position of
Reflection-Transmission Wheel 2b (a Rotation Angle Detector or a
Boundary Region Detector))
[0155] A ring-shaped rotational angle position detecting pattern Sp
is formed around the rotating shaft 2m on the
reflection-transmission wheel 2b as shown in FIG. 17
simplistically. An image sensor Sx forming a part of an encoder is
provided at the opposed position of the rotational angle position
detecting pattern Sp. And, the rotational angle position detecting
pattern Sp is received by the image sensor Sx when passing through
the spot region 2s. The image sensor Sx and the rotational angle
position detecting pattern Sp configure the sensor Se.
[0156] The image sensor Sx outputs the image signal to the CPU. The
CPU can detect the rotational angle position of the
reflection-transmission wheel 2b since the rotational angle
position detecting pattern Sp correspond one-to-one with the
rotational angle position.
[0157] Note that, a potentiometer that the resistance value varies
in proportion to the rotation angle can be used in place of the
sensor Se formed of the rotational angle position detecting pattern
Sp and the image sensor Sx.
[0158] An acceleration sensor can be used to detect the rotational
angle position of the reflection-transmission wheel 2b. As shown in
FIG. 18 simplistically, acceleration is "0 G" when the acceleration
sensor (not shown) is in a horizontal position, and the
acceleration is "1 G" when the acceleration sensor is in a vertical
position. There is a sinusoidal relationship between the angle
.theta.x and the acceleration.
[0159] Thus, the rotational angle position of the
reflection-transmission wheel 2b can be detected by converting a
gravity acceleration G detected by the acceleration sensor provided
on the rotating shaft 2m of the reflection-transmission wheel 2b
into the rotational angle position by a sine function. Note that,
detection of the rotational angle position is not limited to
this.
[0160] In the second embodiments, the on/off control of the light
source 2 and 3 when the region boundary 2r.sub.1, 2r.sub.2 between
the transmission region 2q and the reflection region 2ptraverses
the spot region is described above, but also the on/off control of
the light source 2 and 3 in the rest of the time is obviously
possible.
Third Embodiment
[0161] In the third embodiment, as shown in FIG. 19, light sources
emitting light in the same wavelength .lamda.A (e.g. a blue laser
diode) are used as both of the light source 2 of the first
illumination optical system 1A and the light source 3 of the second
illumination optical system 1B. The configuration of the coupling
lens 3a, the reflection-transmission wheel 2b, the drive part 2n,
and the rotating shaft 2m provided to the first illumination
optical system 1A and the configuration of the coupling lens 3a of
the second illumination optical system 1B are same to the first
embodiment.
[0162] The fluorescent wheel 2e as the second fluorescent wheel is
provided in the transmission light-path of the first illumination
optical system 1A. A pair of collecting elements 2i are provided on
both side of the disk-shaped substrate 2g of the fluorescent wheel
2e. In this embodiment, the disk-shaped substrate 2g of the
fluorescent wheel 2e is formed of a transmissive material.
[0163] The fluorescence property of the fluorescent body 2h of the
fluorescent wheel 2e is same as the first embodiment, i.e., the
fluorescent body 2h is excited by the light in the wavelength
.lamda.A and emits the light in a wavelength .lamda.B (green). The
light in the wavelength .lamda.B is collected by the collecting
element 2i after transmitting the disk-shaped substrate 2g and
reflected by the total reflection mirror 2c to the dichroic mirror
3c.
[0164] The fluorescent wheel 2e' as the first fluorescent wheel is
provided in the reflection light-path of the first illumination
optical system 1A. The disk-shaped substrate 2g' of the fluorescent
wheel 2e' is formed of the transmissive material as with the
disk-shaped substrate 2g of the fluorescent wheel 2e.
[0165] A pair of collecting elements 2i' are provided on both side
of the disk-shaped substrate 2g'. A ring-shaped fluorescent body
2hn is provided on the disk-shaped substrate 2g', and the
fluorescent body 2hn is excited by the light in the wavelength
.lamda.A and emits the light in a wavelength .lamda.C (red). The
light in the wavelength .lamda.C (red; 620 nm to 750 nm) is
collected by the collecting element 2i' after transmitting the
disk-shaped substrate 2g' and led to the dichroic mirror 3b.
[0166] The dichroic mirror 3b has a function that transmits the
light in the wavelength .lamda.A (blue; 400 nm to 450 nm) and
reflects the wavelength .lamda.C (red; 620 nm to 750 nm). The light
in the wavelength .lamda.C is reflected by the dichroic mirror 3b
and led to the dichroic mirror 3c. The dichroic mirror 3c has a
function that transmits the light in the wavelength .lamda.A and
the light in the wavelength .lamda.C and reflects the light in the
wavelength .lamda.B.
[0167] In this embodiment, the light in the wavelength .lamda.A
from the light source 3 of the second illumination optical system
1B is emitted from the illumination optical system 1 after
transmitting the dichroic mirror 3b and the dichroic mirror 3c.
[0168] When the reflection region 2p of the reflection-transmission
wheel 2b is in the light-path of the first illumination optical
system 1A, the light in the wavelength .lamda.A from the light
source 2 is reflected by the reflection region 2p and led to the
fluorescent wheel 2e' provided in the reflection light-path. Then,
the fluorescence in the wavelength .lamda.C is generated by the
light in the wavelength .lamda.A as the excitation light, reflected
by the dichroic mirror 3b, transmits the dichroic mirror 3c, and
emitted from the illumination optical system 1.
[0169] When the transmission region 2q of the
reflection-transmission wheel 2b is in the light-path of the first
illumination optical system 1A, the light in the wavelength
.lamda.A from the light source 2 transmits the transmission region
2q and led to the fluorescent wheel 2eprovided on the transmission
light-path. The fluorescence in the wavelength .lamda.B is
generated by the light in the wavelength .lamda.A as the excitation
light, reflected by the total reflection mirror 2c and the dichroic
mirror 3c, and emitted from the illumination optical system 1.
(An Example of the Irradiation Timing to the Image Generator
16)
[0170] FIG. 20 simplistically illustrates an example of a
relationship among emission timing of the RGB light, on/off timing
of the light source 2 and 3, and reflection/transmission timing of
the reflection-transmission wheel, of the Nth frame of images.
[0171] Here, the creation time of the frame of images is divided
into 3 time period, and the time periods are referred by the
reference numbers a to c. In the time period a, i.e. the rotational
angle position of the region boundary 2r.sub.2 is within the range
of 0 to 90 degrees, the light source 2 is turned on and the light
source 3 is turned off by the control section 11, and the
transmission region 2q is put in the light-path of the first
illumination optical system 1A. Thereby, the image generator 16 is
irradiated with the green light (Gn) in the wavelength
.lamda.B.
[0172] In the time period b, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 180 to 270
degrees, the light source 2 is turned on and the light source 3 is
turned off by the control section 11, and the reflection region 2p
of the reflection-transmission wheel 2b is put in the light-path of
the first illumination optical system 1A. Thereby, the image
generator 16 is irradiated with the red light (Rn) in the
wavelength .lamda.C.
[0173] In the time period c, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 270 to 360
degrees, the light source 2 is turned off and the light source 3 is
turned on by the control section 11, and the transmission region 2q
of the reflection-transmission wheel 2b is put in the light-path of
the first illumination optical system 1A. Thereby, the image
generator 16 is irradiated with the blue light (Bn) in the
wavelength .lamda.A.
[0174] Thus, according to this embodiment, each color of RGB can
irradiates the image generator 16 in a time frame of the image, and
the projection of the full-color images and the white rite become
available by use of persistence of vision.
[0175] A color tone can be varied by adjusting or changing the
length of the time period a, b, and c. For example, to make the
projection image being tinged with red by lengthening the time
period a in one frame. Furthermore, color temperature can be
changed by adjusting or changing the time periods a, b, and c frame
by frame.
[0176] Also, in this Embodiment, the brightness of projected image
can be improved while the region boundary 2r.sub.1, 2r.sub.2
between the transmission region 2q and the reflection region 2p of
the reflection-transmission wheel 2b traverses the spot region
2s.
(Other Example of the Emission Timing to the Image Generator
16)
[0177] FIG. 21 simplistically illustrates other example of a
relationship among emission timing of the RGB light, on/off timing
of the light source 2 and 3, and reflection/transmission timing of
the reflection-transmission wheel 2b, of the Nth frame of
images.
[0178] In the other example, the Nth time period a is divided into
the time period a1 and the time period a2, while the Nth time
period b is divided into the time period b1 and the time period b2.
In the time period a1, i.e. the rotational angle position of the
region boundary 2r.sub.2 is within the range of 0 to 90 degrees,
the light source 2 is turned on and the light source 3 is turned
off by the control section 11. Furthermore, the transmission region
2q is put in the light-path of the first illumination optical
system 1A. Thereby, the image generator 16 is irradiated with the
green light (Gn) in the wavelength .lamda.B.
[0179] In the time period a2, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 90 to 180
degrees, the light source 2 and the light source 3 is turned on in
the same time, and the transmission region 2q is put in the
light-path of the first illumination optical system 1A. Thereby,
the cyan illumination light is generated by mixture of the green
light in the wavelength .lamda.B and the blue light in the
wavelength .lamda.A, and the image generator 16 is irradiated with
the cyan illumination light.
[0180] In the time period b1, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 180 to 225
degrees, the light source 2 is turned on and the light source 3 is
turned off by the control section 11. Furthermore, the reflection
region 2p of the reflection-transmission wheel 2b is put in the
light-path of the first illumination optical system 1A. Thereby,
the image generator 16 is irradiated with the red light (Rn) in the
wavelength .lamda.C.
[0181] In the time period b2, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 225 to 270
degrees, the light source 2 is turned on and the light source 3 is
turned off by the control section 11. Furthermore, the reflection
region 2p of the reflection-transmission wheel 2b is put in the
light-path of the first illumination optical system 1A. Thereby,
the magenta (Mn) illumination light is generated by mixture of the
red (Rn) light in the wavelength .lamda.C and the blue light (Bn)
in the wavelength .lamda.A, and the image generator 16 is
irradiated with the magenta illumination light.
[0182] In the time period c, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 270 to 360
degrees, the light source 2 is turned off and the light source 3 is
turned on, and the transmission region 2q of the
reflection-transmission wheel 2b is put in the light-path of the
first illumination optical system 1A. Thereby, the image generator
16 is irradiated with the blue light (Bn) in the wavelength
.lamda.A. Also in this case, the occurrence of color mixture is
prevented while the brightness of projected image can be improved.
Therefore, a brighter projected image can be generated.
Fourth Embodiment
[0183] In this fourth embodiment, as shown in FIG. 22, FIG. 23, a
collecting element 2w is provided in the light-path of the first
illumination optical system 1A in addition to the third embodiment,
the coupling lens 2x is provided in the transmission light-path,
and the coupling lens 2x' is provided in the reflection light-path.
The collecting element 2w and the coupling lens 2x, 2x' configure
the second optical element together.
[0184] According to the fourth embodiment, as shown in FIG. 23, the
light in the wavelength .lamda.A emitted from the light source 2 is
collected by the coupling lens 2a, led to the collecting element 2w
as a parallel beam, and converged by the collecting element 2w, and
led to the reflection-transmission wheel 2b.
[0185] When the reflection region 2p is in the light-path of the
first illumination optical system 1A, the converged light in the
wavelength .lamda.A is reflected by the reflection region 2p, led
to the coupling lens 2x', led to the collecting element 2i' by the
coupling lens 2x' as the parallel beam, converged by the collecting
element 2i', and irradiates the fluorescent body 2hn.
[0186] When the transmission region 2q is in the light-path of the
first illumination optical system 1A, the converged light in the
wavelength .lamda.A transmits the transmission region 2q and is led
to the coupling lens 2x, led to the collecting element 2i by the
coupling lens 2x as the parallel beam, converged by the collecting
element 2i, and irradiates the fluorescent body 2h.
[0187] In the fourth embodiment, as shown in FIG. 24, the dimension
of the spot region 2s' can be reduced in size compared to the size
of the spot region 2s of the first illumination optical system 1A
in the third embodiment, since a beam in the wavelength .lamda.A
irradiates the reflection-transmission wheel 2b after being
converged.
[0188] Thus, the time that the region boundary 2r.sub.1, 2r.sub.2
between the transmission region 2q and the reflection region 2p of
the reflection-transmission wheel 2b passing through the spot
region 2s' can be shorten.
[0189] Therefore, according to the fourth embodiment, the color
reproducibility and the brightness of the images can be improved
since the creation time of the mixed color light can be adjusted by
changing the dimension of the spot region 2s.
[0190] Detailed descriptions are omitted since the other of the
configuration and functions are similar to that in the third
embodiment.
Fifth Embodiment
[0191] In this embodiment, the number of the light source of the
illumination optical system 1 is one. For this light source, the
light source emitting the light in the wavelength .lamda.A (blue)
as with the first embodiment is used, and referred to as the same
reference number 2 as shown in FIG. 25.
[0192] As shown in FIG. 26, the reflection-transmission wheel 2b is
formed of the reflection region 2p and the transmission region 2q
being arranged symmetrically with respect to a straight line
passing through the center of the rotating shaft 2m. The rest of
the configuration and the total reflection mirror 2c will be
described with the same reference numbers as shown in FIG. 1, since
they are similar to the first embodiment.
[0193] In FIG. 26, the straight line passing through the center of
the rotating shaft 2m is divided into two lines at the rotating
shaft 2m, and one of them is referred as the radial region boundary
2r.sub.1, and another one is referred as the radial region boundary
2r.sub.2.
[0194] As shown in FIG. 27, the ring-shaped fluorescent body 2h of
the fluorescent wheel 2e is formed of a semicircular fluorescent
body 2h' emitting the fluorescence in the wavelength .lamda.B
(green) and a semicircular fluorescent body 2h'' emitting the
fluorescence in the wavelength .lamda.C (red) different from the
wavelength .lamda.B. In this embodiment, the disk-shaped substrate
2g is divided into two parts, and semicircular fluorescent bodies
2h', 2h'' are formed on the disk-shaped substrate 2g, but the
configuration of the fluorescent body 2h is not limited
thereto.
[0195] In FIG. 27, a straight line passing through the center of
the rotating shaft 2j and forming the boundary between the
semicircular fluorescent body 2h' and the semicircular fluorescent
body 2h'' is divided into two lines at the rotating shaft 2j, one
of the lines is referred to a radial region boundary 2r.sub.3 and
another one of the lines is referred to a radial region boundary
2r.sub.4.
[0196] The dichroic mirror 3b is provided in the reflection
light-path of the reflection-transmission wheel 2b, and the
dichroic mirror 3c is provided in the transmission light-path. The
dichroic mirror 3b has a function that transmits the light in the
wavelength .lamda.A, and reflects the light in the wavelength
.lamda.B, .lamda.C.
[0197] The drive part 2f is formed of, for example, a stepping
motor. The disk-shaped substrate 2g is rotationally driven on the
rotating shaft 2j based on a predetermined rotational angle
position of the semicircular fluorescent body 2h', h''. The blue
light in the wavelength .lamda.A irradiates the
reflection-transmission wheel 2b when the light source 2 is turned
on.
[0198] When the transmission region 2q is in the light-path of the
illumination optical system 1, the blue light in the wavelength
.lamda.A is led to the transmission region 2q by the coupling lens
2a as a parallel beam and transmits the transmission region 2q,
reflected by the total reflection mirror 2c, led to the dichroic
mirror 3c, reflected by the dichroic mirror 3c and emitted from the
illumination optical system 1.
[0199] When the reflection region 2p is in the light-path of the
illumination optical system 1, the blue light in the wavelength
.lamda.A is led to the reflection region 2p by the coupling lens 2a
as a parallel beam, reflected by the reflection region 2p, led to
the collecting element 2i after transmitting the dichroic mirror
3c, converged by the collecting element 2i, and irradiates the
fluorescent wheel 2e.
[0200] When the semicircular fluorescent body 2h' of the
fluorescent body 2h is irradiated with the blue light in the
wavelength .lamda.A converged, the fluorescence in the wavelength
.lamda.B (green) is generated by the blue light as the excitation
light, and when the semicircular fluorescent body 2h'' is
irradiated with the blue light in the wavelength .lamda.A
converged, the fluorescence in the wavelength .lamda.C (red) is
generated by the blue light as the excitation light.
[0201] The fluorescence in the wavelength .lamda.B or .lamda.C is
collected by the collecting element 2i and led to the dichroic
mirror 3b, reflected by the dichroic mirror 3b, and emitted from
the illumination optical system 1 after transmitting the dichroic
mirror 3c.
(An Example of Irradiation Timing to the Image Generator 16)
[0202] FIG. 28 simplistically illustrates an example of a
relationship among the irradiation timing of the RGB light, the
reflection/transmission timing of the reflection-transmission wheel
2b, and the fluorescent wheel 2e of Nth image frame in the fifth
embodiment.
[0203] An Nth time frame of images is divided into four time period
a, b, c and d. In the time period a, i.e. the rotational angle
position of the region boundary 2r.sub.2 is within the range of 45
to 67.5 degrees (the rotational angle position of the region
boundary 2r.sub.3 is within the range of 0 to 90 degrees), the
reflection region 2p is put in the light-path of the first
illumination optical system 1A by the control section 11.
Furthermore, the rotational angle position of the fluorescent wheel
2e is controlled by the control section 11 so that the semicircular
fluorescent body 2h' of the fluorescent wheel 2e is irradiated with
the light in the wavelength .lamda.A.
[0204] Thereby, the green fluorescence (Gn) in the wavelength
.lamda.B is generated and emitted from the illumination optical
system 1 via the dichroic mirror 3b, 3c, and irradiates the image
generator 16.
[0205] In the time period b, i.e. the rotational angle position of
the region boundary 2r.sub.2 is within the range of 67.5 to 90
degrees (the rotational angle position of the region boundary
2r.sub.3 of the fluorescent wheel 2e is within the range of 90 to
180 degrees), the reflection region 2p of the
reflection-transmission wheel 2b is put in the light-path of the
first illumination optical system 1A by the control section 11.
Furthermore, the rotational angle position of the fluorescent wheel
2e is controlled by the control section 11 so that the semicircular
fluorescent body 2h'' of the fluorescent wheel 2e is irradiated
with the light in the wavelength .lamda.A.
[0206] Thereby, the red fluorescence (Rn) in the wavelength
.lamda.C is generated and emitted from the illumination optical
system 1 via the dichroic mirror 3b, 3c, and irradiates the image
generator 16.
[0207] In the time period c, d, i.e. the rotational angle position
of the region boundary 2r.sub.2 is within the range of 90 to 135
degrees (the rotational angle position of the region boundary
2r.sub.3 of the fluorescent wheel 2e is within the range of 180 to
360 degrees), the transmission region 2q of the
reflection-transmission wheel 2b is put in the light-path of the
first illumination optical system 1A by the control section 11. The
blue light (Bn) in the wavelength .lamda.A transmits the
transmission region 2q, and is reflected by the total reflection
mirror 2c and the dichroic mirror 3c, and emitted from the
illumination optical system 1. At that time, the rotational angle
position of the fluorescent wheel 2e is arbitrarily-selected.
[0208] Also, in the fifth embodiment, the full-color images can be
generated and the white light can be projected as is the case in
the first, third and fourth embodiments, since the image generator
16 can be irradiated with the light of the RGB color in a time
frame. Furthermore, as is the case in the third embodiment, the
color tone and the color temperature can be varied. A detailed
description of the projection device is omitted since the
projection device identical to the second embodiment is applicable
except optical components of the illumination optical system 1.
[0209] According to the fifth embodiment, the illumination optical
system 1 can be downsized, and the production cost can be reduced,
since the number of the optical element of the illumination optical
system 1 for the light source can be reduced to be one.
(An Example of Controlling in High-Intensity)
[0210] FIG. 29A to FIG. 29G illustrates a relationship between the
rotational angle position of the reflection-transmission wheel and
the spot region 2s. FIG. 30A to FIG. 30G illustrate a relationship
between the rotational angle position of the fluorescent wheel 2e
and the spot region 2s''.
[0211] Note that, in this embodiment, the rotational angle position
detecting part of the fluorescent wheel 2e is provided.
[0212] In this embodiment, it is assumed that the light source 2 is
turned on when the boundary region 2r.sub.2 traverses the spot
region 2s, whereas the light source 2 is turned on/off when the
boundary region 2r.sub.1, 2r.sub.2 traverses the spot region 2s in
the first embodiment.
[0213] As shown in FIG. 26, when the boundary region 2r.sub.2 of
the reflection-transmission wheel 2b traverses the spot region 2s,
a half of the light in the wavelength .lamda.A transmits the
transmission region 2q, and the other half is reflected by the
reflection region 2p and led to the fluorescent wheel 2e through
the reflection light-path.
[0214] As shown in FIG. 27, when the boundary region 2r.sub.3 of
the fluorescent wheel 2e traverses the spot region 2s'', the light
in the wavelength .lamda.A from the light source 2 as the
excitation light excites the semicircular fluorescent body 2h' and
generates the light in the wavelength .lamda.B, simultaneously
excites the semicircular fluorescent body 2h'' and generates the
light in the wavelength .lamda.C. The fluorescence is emitted from
the illumination optical system 1 via the collecting element 2i,
the dichroic mirror 3b, and 3c. Thus, the mixed colored light can
be generated.
[0215] Thus, the control section 11 judges the rotational angle
position of the reflection-transmission wheel 2b and the rotational
angle position of the fluorescent wheel 2e, and controls the
lighting of the light source 2. The angle .theta. formed by the two
tangent lines 2r.sub.1', 2r.sub.2' extended in the radial direction
from the center of the rotating shaft 2m and that contacts the spot
region 2s is dependent on a radius of the spot region 2s, and the
distance from the center of the rotating shaft 2m to the center of
the spot region 2s (the optical axis O1)
[0216] Here, the angle .theta. is, for example, 90 degrees. When
the region boundary 2r.sub.1, 2r.sub.2 of the
reflection-transmission wheel 2b is in a fun-shaped region .beta.
enclosed by the two tangent lines 2r.sub.1', 2r.sub.2' and an arc,
and the light source 2 is turned on, the light in the wavelength
.lamda.A (blue) transmits the transmission region 2q and is
reflected by the reflection region 2p at the same time.
[0217] The color mixture is also generated when the region boundary
2r.sub.3, 2r.sub.4 traverses the spot region 2s''. Also, as
regarding the fluorescent wheel 2e, the angle .theta.'' formed by
the two tangent lines 2r.sub.1'', 2r.sub.2'' extended in the radial
direction from the center of the rotating shaft 2j and contacts the
spot region 2s'' is dependent on the radius of the spot region 2s''
and the distance from the center of the rotating shaft 2j to the
center of the spot region 2s''.
[0218] Here, it is assumed that the fluorescent wheel 2e rotates in
rotating speed of 4 times of the reflection-transmission wheel 2b,
and the angle .theta.'' is 60 degrees. Note that, the angle
.theta.', .theta.'' is indicated specifically just for convenience
of description, and not limited to the angle .theta.',
.theta.''.
[0219] As shown in FIG. 29A, it is assumed that the
reflection-transmission wheel 2b starts rotation when the
rotational angle position of the region boundary 2r.sub.2 is within
the 45 degrees to the reference angle of 0 degrees, whereas, the
fluorescent wheel 2e starts rotation when the region boundary
2r.sub.3 is in the reference angle i.e. 0 degrees as shown in FIG.
30A.
[0220] FIG. 31 illustrates a relationship among the rotational
angle position of each wheel, the rotational phase of each wheels,
and a color of light irradiating the image generator when the light
source 2 is turned on, when the reflection-transmission wheel shown
in FIG. 26 and the fluorescent wheel shown in FIG. 27 are used.
[0221] That is to say, a relationship among the rotation angle
(rotational phase) of the region boundary 2r.sub.2, 2r.sub.1 of the
reflection-transmission wheel 2b, the rotation angle (rotational
phase) of the region boundary 2r.sub.3, 2r.sub.4 of the fluorescent
wheel 2e, and a color of light emitted by the illumination optical
system 1 and irradiates the image generator 16 when the light
source 2 is turned on is illustrated.
[0222] It is shown in FIG. 31 that the rotation angle of four
revolution of the fluorescent wheel 2e to the rotation angle of one
revolution of the reflection-transmission wheel 2b. The rotational
angle position of the reflection-transmission wheel 2b is shown by
15-degree scale whereas the rotational angle position of the
fluorescent wheel 2e is shown by 60-degree scale.
[0223] It is assumed that the rotational phase of the
reflection-transmission wheel 2b is "0" when the region boundary
2r.sub.2, 2r.sub.1 is in the spot region 2s and "1" when the region
boundary 2r.sub.2, 2r.sub.1 is out of the spot region 2s, on the
other hand, the rotational phase of the fluorescent wheel 2e is "0"
when the region boundary 2r.sub.3, 2r.sub.4 is in the spot region
2s.
[0224] Hereinafter, a relationship between the rotational phases of
the reflection-transmission wheel 2b and the fluorescent wheel 2e,
and the on-state of the light source 2 will be described in detail
with reference to FIG. 29A to 29G, FIG. 30A to 30G, and FIG. 31. It
is assumed that the fluorescent wheel 2e rotates four revolutions
per one revolution of the reflection-transmission wheel 2b.
[0225] The rotational phase of the reflection-transmission wheel 2b
is "0" when the rotational angle position of the region boundary
2r.sub.2 of the reflection-transmission wheel 2b is within the
range of 45 to 135 degrees (see FIG. 29A and FIG. 29B), since the
region boundary 2r.sub.2 traverses the spot region 2s. On the other
hand, the rotational phase of the reflection-transmission wheel 2b
is "1" when the rotational angle position of the region boundary
2r.sub.2 of the reflection-transmission wheel 2b is within the
range of 135 to 225 degrees (see FIG. 29B to FIG. 29G), since
neither of the region boundaries 2r.sub.1 and 2r.sub.2 of the
reflection-transmission wheel 2b traverse the spot region 2s.
[0226] Light intensity of the excitation light (light B) is
increased (see FIG. 31 B1) when the rotational angle position of
the region boundary 2r.sub.2 is within the range of 45 to 135
degrees, since the spot region 2s relatively moves from the
reflection region 2p to the transmission region 2q.
[0227] The light intensity of the excitation light (light B) is
constant (see FIG. 31 B2) when the rotational angle position of the
region boundary 2r.sub.2 is within the range of 135 to 225 degrees,
since the spot region 2s is only in the transmission region 2q.
[0228] the rotational phase of the reflection-transmission wheel 2b
is "0" when the rotational angle position of the region boundary
2r.sub.2 of the reflection-transmission wheel 2b is within the
range of 225 to 315 degrees (not shown), i.e., the rotational angle
position of the region boundary 2r.sub.1 is within the range of 45
to 135 degrees, since the region boundary 2r.sub.1 traverses the
spot region 2s.
[0229] The light intensity of the excitation light (light B)
emitted from illumination optical system 1 and irradiates the image
generator 16 is increased (see the reference number B3 in FIG. 31)
when the rotational angle position of the region boundary 2r.sub.2
is within the range of 225 to 315 degrees, since the spot region 2s
relatively moves from the transmission region 2q to the reflection
region 2p.
[0230] The rotational phase of the reflection-transmission wheel 2b
is "1" when the rotational angle position of the region boundary
2r.sub.2 of the reflection-transmission wheel 2b is within the
range of 315 to 45 degrees (not shown), i.e., the rotational angle
position of the region boundary 2r.sub.1 is within the range of 135
to 225 degrees, since neither of the region boundaries 2r.sub.1 and
2r.sub.2 traverse the spot region 2s.
[0231] When the rotational angle position of the region boundary
2r.sub.2 is within the range of 315 to 45 degrees, the spot region
2s is only in the reflection region 2p. The excitation light (light
B) is not emitted by the illumination optical system 1 and does not
irradiates the image generator 16 (see the reference number B4 in
FIG. 31).
[0232] The rotational phase of the fluorescent wheel 2e is "1" when
the rotational angle position of the region boundary 2r.sub.3 of
the fluorescent wheel 2e is within the range of 0 to 60 degrees
(see FIG. 30B and FIG. 30C), since neither of the region boundaries
2r.sub.3, 2r.sub.4 traverse the spot region 2s''.
[0233] The green fluorescence (G light) is generated and emitted
from the illumination optical system 1 and irradiates the image
generator 16 (see the reference number G1 in FIG. 31) whereas red
fluorescence (R light) is not generated (see the reference number
R1 in FIG. 31) when the rotational angle position of the region
boundary 2r.sub.3 is within the range of 0 to 60 degrees, since the
spot region 2s'' is only in the semicircular fluorescent body
2h'.
[0234] The rotational phase of the fluorescent wheel 2e is "0" when
the rotational angle position of the region boundary 2r.sub.3 of
the fluorescent wheel 2e is within the range of 60 to 120 degrees
(see FIG. 30C and FIG. 30D), since the region boundary 2r.sub.3
traverses the spot region 2s''.
[0235] The light intensity of the G light which is emitted by
illumination optical system 1 and irradiates the image generator 16
is decreased (see FIG. 31 G2), and the R light which is emitted by
illumination optical system 1 and irradiates the image generator 16
is increased (see FIG. 31 R2) when the rotational angle position of
the region boundary 2r.sub.3 is within the range of 60 to 120
degrees, the spot region 2s'' relatively moves from the
semicircular fluorescent body 2h' to the semicircular fluorescent
body 2h''.
[0236] The rotational phase of the fluorescent wheel 2e is "1" when
the rotational angle position of the region boundary 2r.sub.3 of
the fluorescent wheel 2e is within the range of 120 to 240 degrees
(see FIG. 30D and FIG. 30E), since neither of the region boundaries
2r.sub.3, 2r.sub.4 traverse the spot region 2s''.
[0237] The R light which is emitted by the illumination optical
system 1 and irradiates the image generator 16 is constant (see the
reference number R3 in FIG. 31) if the light intensity of the
excitation light reflected by the reflection region 2p is constant
when the rotational angle position of the region boundary 2r.sub.3
is within the range of 120 to 240 degrees, since the spot region
2s'' is only in the semicircular fluorescent body 2h''. On the
other hand, the G light is not emitted by the illumination optical
system 1 and does not irradiates the image generator 16 (see FIG.
31 G3) since the spot region 2s'' is not in the semicircular
fluorescent body 2h'.
[0238] Note that, the light intensity of the R light is not
constant in practice since the light intensity of the reflected
excitation light is increased or decreased while the rotational
phase of the reflection-transmission wheel 2b is "0".
[0239] The rotational phase of the fluorescent wheel 2e is "0" when
the rotational angle position of the region boundary 2r.sub.3 of
the fluorescent wheel 2e is within the range of 245 to 300 degrees
(see FIGS. 30E, 30F), since the region boundary 2r.sub.4 traverses
the spot region 2s''.
[0240] When the rotational angle position of the region boundary
2r.sub.3 is within the range of 240 to 300 degrees, the spot region
2s'' relatively moves from the semicircular fluorescent body 2h''
to the semicircular fluorescent body 2h'. The light intensity of
the R light which is emitted by illumination optical system 1 and
irradiates the image generator 16 is decreased (see the reference
number R4 in FIG. 31), and the B light which is emitted by
illumination optical system 1 and irradiates the image generator 16
is increased (see the reference number G4 in FIG. 31).
[0241] The rotational phase of the fluorescent wheel 2e is "1" when
the rotational angle position of the region boundary 2r.sub.3 of
the fluorescent wheel 2e is within the range of 300 to 60 degrees
(see FIG. 30F and FIG. 30G), since neither of the region boundaries
2r.sub.3 and 2r.sub.4 traverse the spot region 2s''.
[0242] Therefore, the relationship of the rotational phase of the
fluorescent wheel 2e to the reflection-transmission wheel 2b in one
revolution of the reflection-transmission wheel 2b is that
illustrated in FIG. 31.
[0243] The spot region 2s'' is in the semicircular fluorescent body
2h' when the rotational angle position of the region boundary
2r.sub.3 is within the range of 300 to 60 degrees. At the time, the
G light is emitted by the illumination optical system 1 and
irradiates the image generator 16 (see the reference number G5 in
FIG. 31) while the region boundary 2r.sub.3 is within the range of
300 to 0 degrees since the excitation light .lamda.A is led to the
fluorescent wheel 2e by the reflection region 2p.
[0244] Therefore, the colors of light emitted by the illumination
optical system 1 while the fluorescent wheel 2e rotates one
revolution, equal to that the reflection-transmission wheel 2b
rotates from the angle 45 to 135 degrees are cyan (C), white (W),
magenta (M), white (W), and cyan (C).
[0245] Furthermore, the color of light emitted by the illumination
optical system 1 while the fluorescent wheel 2e rotates one
revolution, equal to that the reflection-transmission wheel 2b
rotates from the angle 135 to 225 degrees, is blue (B).
[0246] Similarly, the colors of light emitted by the illumination
optical system 1 while the fluorescent wheel 2e rotates one
revolution, equal to that the reflection-transmission wheel 2b
rotates from the angle 225 to 315 degrees, are cyan (C), white (W),
magenta (M), white (W), and cyan (C).
[0247] Also, the colors of light emitted by the illumination
optical system 1 while the fluorescent wheel 2e rotates one
revolution, equal to that the reflection-transmission wheel 2b
rotates from the angle 315 to 45 degrees, are green (G), yellow
(Y), red (R), yellow (Y), and green (G) since there is no B light
transmitting the transmission region 2p in this angular range.
[0248] In this embodiment, it is assumed that the fluorescent wheel
2e rotates in rotating speed of 4 times of the
reflection-transmission wheel 2b, but the rotating speed is not
limited thereto.
[0249] Since the rotational angle position of the
reflection-transmission wheel 2b and the rotational angle position
of the fluorescent wheel 2e can be detected by the rotational angle
position detector, each colored light of red, green, blue, cyan,
magenta, yellow, and white can be generated by controlling the
timing of the lighting of the light source 2 and the image
generator 16 (DMD), when the dimension of the spot region 2s'' is
detected.
[0250] The dimension of the spot regions 2s, 2s'' can be determined
at the planning phase and memorized in the RAM or the like in the
control section 11, and additionally the varying in the dimension
of the spot regions 2s, 2s'' depending on the driving of the
coupling lens 2a in direction of the optical axis can be obtained
by calculations based on the reference dimension of the spot
regions 2s, 2s'' which are preset in advance.
[0251] Furthermore, the relationship between the rotating speed of
the fluorescent wheel 2e and the rotating speed of
reflection-transmission wheel 2b can be memorized as a table.
[0252] Although the present invention has been described in terms
of exemplary embodiments, it is not limited thereto. It should be
appreciated that variations may be made in the embodiments
described by persons skilled in the art without departing from the
scope of the present invention as defined by the following
claims.
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