U.S. patent application number 11/367373 was filed with the patent office on 2006-07-06 for illumination optical system, image display apparatus using same and image display method.
This patent application is currently assigned to SAMSUNG ELECTRONIC CO., LTD.. Invention is credited to Kun-ho Cho, Dae-sik Kim, Sung-ha Kim, Hee-joong Lee.
Application Number | 20060146414 11/367373 |
Document ID | / |
Family ID | 36640079 |
Filed Date | 2006-07-06 |
United States Patent
Application |
20060146414 |
Kind Code |
A1 |
Cho; Kun-ho ; et
al. |
July 6, 2006 |
Illumination optical system, image display apparatus using same and
image display method
Abstract
An illuminating optical system including a lamp light source and
a reflecting mirror device. The lamp light source emits light. The
reflecting mirror device having double reflecting mirror arrays
formed in at least a portion thereof which at least partly adjust a
divergent direction of light emitted from the lamp light
source.
Inventors: |
Cho; Kun-ho; (Gyeonggi-do,
KR) ; Kim; Dae-sik; (Gyeonggi-do, KR) ; Kim;
Sung-ha; (Gyeonggi-do, KR) ; Lee; Hee-joong;
(Gyeonggi-do, KR) |
Correspondence
Address: |
STAAS & HALSEY LLP
SUITE 700
1201 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
SAMSUNG ELECTRONIC CO.,
LTD.
Suwon-si
KR
|
Family ID: |
36640079 |
Appl. No.: |
11/367373 |
Filed: |
March 6, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10654614 |
Sep 4, 2003 |
|
|
|
11367373 |
Mar 6, 2006 |
|
|
|
Current U.S.
Class: |
359/634 ;
348/E9.027 |
Current CPC
Class: |
G02B 27/0977 20130101;
G02B 27/286 20130101; H04N 9/3117 20130101; H04N 9/315
20130101 |
Class at
Publication: |
359/634 |
International
Class: |
G02B 27/14 20060101
G02B027/14 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 4, 2002 |
KR |
2002-53320 |
Claims
1. An illuminating optical system comprising: a lamp light source
which emits light; and a reflecting mirror device having double
reflecting mirror arrays formed in at least a portion thereof which
at least partly adjust a divergent direction of the light emitted
from the lamp light source.
2. The illuminating optical system of claim 1, wherein the
reflecting mirror device includes first through fourth reflecting
regions which are sequentially disposed along a rotational
direction thereof, and the double reflecting mirror arrays are
formed in the first and third reflecting regions or the second and
fourth reflecting regions.
3. The illuminating optical system of claim 2, wherein the
reflecting mirror device adjusts a divergent direction of the light
emitted from the lamp light source so that the light is converted
into elliptical or near-elliptical light.
4. The illuminating optical system of claim 2, wherein an angle of
a mirror surface of the double reflecting mirror arrays is
45.degree..
5. The illuminating optical system of claim 1, wherein the
reflecting mirror device adjusts a divergent direction of the light
emitted from the lamp light source so that the light is converted
into elliptical or near-elliptical light.
6. The illuminating optical system of claim 5, wherein an angle of
a mirror surface of the double reflecting mirror arrays is
45.degree..
7. The illuminating optical system of claim 1, wherein an angle of
a mirror surface of the double reflecting mirror arrays is
45.degree..
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Divisional of U.S. patent application
Ser. No. 10/654,614, filed Sep. 4, 2003, currently pending, and
claims the benefit of priority of Korean Patent Application No.
2002-53320, filed on Sep. 4, 2002, in the Korean Intellectual
Property Office, the disclosures of which are incorporated herein
by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an illuminating optical
system and an image display apparatus using the same, and more
particularly, to highly efficient illuminating optical system with
high optical efficiency, an image display apparatus using the same,
and an image display method.
[0004] 2. Description of the Related Art
[0005] Projection type image display apparatuses focus light
emitted from a light source on a microdisplay, that is, a light
valve such as, for example, a liquid crystal display (LCD) or a
digital microdisplay (DMD) and control the light on a
pixel-by-pixel basis, thereby forming an image. The formed image is
magnified and projected on a screen using a projection optical
device, thereby providing a wide picture.
[0006] In the image display apparatuses, brightness of an image
depends on the intensity of light condensed on the light valve.
[0007] A conventional illuminating optical system typically
includes a fly eye lens or a glass rod for efficiently condensing
light emitted from a lamp light source on a rectangular shaped
light valve.
[0008] The aforementioned conventional illuminating optical system
is not without problems. For example, when using the lamp light
source as a light source, light emitted from the lamp light source
is incident on the fly eye lens or the glass rod without changing
the shape of the light, thereby reducing optical efficiency. More
specifically, while circular light is emitted from the lamp light
source, the fly eye lens or the glass rod has a rectangular shape
corresponding to the rectangular shaped light valve. Thus, when the
circular light emitted from the lamp light source is incident on
the rectangular shaped fly eye lens or the glass rod, light loss is
caused due to a difference in shapes.
[0009] For example, light emitted from the lamp light source passes
through a first fly eye lens, and then is formed as a light spot on
a second fly eye lens. If a size of the light spot is larger than
that of the second fly eye lens, the portion beyond the size of the
second fly eye lens is lost, thereby reducing the optical
efficiency.
[0010] Further, if the light spot formed by the first fly eye lens
is not beyond the second fly eye lens, the power of the first fly
eye lens must increase and a distance between the first fly eye
lens and the second fly eye lens must be short. However, in this
case, an effective area of the light valve is reduced. If the
effective area of the light valve is reduced, condensing light on
the light valve is difficult, thereby reducing the optical
efficiency.
SUMMARY OF THE INVENTION
[0011] The present invention provides an illuminating optical
system with high efficiency by adjusting a divergent direction of
light emitted from a lamp light source and a projection type image
display apparatus using the same.
[0012] Additional aspects and/or advantages of the invention will
be set forth in part in the description which follows and, in part,
will be obvious from the description, or may be learned by practice
of the invention.
[0013] According to an aspect of the present invention, there is
provided an illuminating optical system including a lamp light
source which emits light; and a reflecting mirror device having
double reflecting mirror arrays formed in at least a portion
thereof which at least partly adjust a divergent direction of light
emitted from the lamp light source.
[0014] The reflecting mirror device may include first through
fourth reflecting regions which are sequentially disposed along a
rotational direction thereof, and the double reflecting mirror
arrays are formed in the first and third reflecting regions or the
second and fourth reflecting regions.
[0015] The reflecting mirror device may adjust a divergent
direction of light emitted from the lamp light source so that the
light is converted into elliptical or near-elliptical light.
[0016] An angle of a mirror surface of the double reflecting mirror
arrays may be 45.degree..
[0017] According to another aspect of the present invention, there
is provided an image display apparatus including an illuminating
optical system which includes a lamp light source and a reflecting
mirror device having double reflecting mirror arrays formed in at
least a portion thereof for at least partly adjusting a divergent
direction of light emitted from the lamp light source; and a light
valve which controls light emitted from the lamp light source and
then reflected by the reflecting mirror device on a pixel-by-pixel
basis according to an input image signal and form a color
image.
[0018] The image display apparatus may further comprise a light
mixture device and a relay lens which are disposed between the
reflecting mirror device and the light valve.
[0019] The light mixture device may be a glass rod. The image
display apparatus may further comprise a condensing lens which
condenses light passed through the reflecting mirror device and
inputs the light to the glass rod.
[0020] The light mixture device may include two fly eye lenses.
[0021] The image display apparatus may further comprise a colored
light separator, which separates light emitted from the lamp light
source according to wavelength, to form a color image.
[0022] The colored light separator may include three or more
dichroic filters.
[0023] The image display apparatus may further include a spiral
lens, in which lens cells are formed spirally in order to obtain
the effect of rectilinear motion of a lens cell array due to the
rotation of the spiral lens cell array, so that a scrolling
operation of the light emitted from the lamp light source is
performed.
[0024] According to still another aspect of the present invention,
there is provided an image display apparatus projection system
including an illuminating optical system and a light mixing
section. The illuminating optical system includes a light
generating section which emits a light beam and a light beam shape
adjusting section including a reflecting mirror device which
adjusts the shape of the light beam.
[0025] According to yet another aspect of the present invention,
there is provided an image display apparatus including an
illuminating optical system, a light valve, a scrolling unit, a
colored light separator, and a pair of fly-eye lenses. The
illuminating optical system includes a light source which emits
light disposed at a light emitting end of a light path and a light
shape adjuster disposed on the light path which adjusts the shape
of the light beam emitted by the light source so as to output a
shape adjusted light beam. The light valve forms a color image by
turning pixels one of on and off according to an input image signal
and disposed at an image forming end of the light path. The
scrolling unit is disposed on the light path between the
illuminating optical device and the light valve, receives the shape
adjusted light beam, and scrolls the shape adjusted light beam. The
colored light separator separates the shape adjusted light beam
emitted from the scrolling unit into color beams according to
wavelength. The pair of fly-eye lenses is disposed on the light
path between the colored light separator and the light valve,
receives the scrolling color beams, focuses the color beams onto a
relay lens disposed on the light path between the pair of fly-eye
lenses and the light valve, and transmits to the light valve
received color beams from the pair of fly-eye lenses. The scrolling
causes the color beams to be received by the light valve at
different portions thereof.
[0026] According to still another aspect of the present invention,
there is provided a method of displaying an image, including:
emitting a light beam; adjusting a divergent angle of the light
beam so as to adjust a shape thereof; focusing the shape adjusted
light beam onto a light valve and turning pixels of the light valve
one of on and off according to a received image signal so as to
form a color image; magnifying the color image; and projecting the
magnified color image onto a screen.
[0027] According to yet another aspect of the present invention,
there is provided a method of displaying an image, including:
emitting a light beam; adjusting a divergent angle of the light
beam so as to adjust a shape thereof; separating the shape adjusted
light beam into a plurality of color beams according to wavelength;
focusing the color beams onto a light valve and turning pixels of
the light valve one of on and off according to a received image
signal so as to form a color image; magnifying the color image; and
projecting the magnified color image onto a screen.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] These and/or other aspects and advantages of the invention
will become apparent and more readily appreciated from the
following description of the embodiments taken in conjunction with
the accompanying drawings in which:
[0029] FIG. 1 schematically shows a conventional lamp light source
used as a light source of a projection type image display
apparatus;
[0030] FIG. 2 shows approximate circular light emitted from the
lamp light source of FIG. 1, in which a plurality of luminous
bodies having a divergent angle distribution diverging in an
elliptical shape are distributed in an axis symmetric
direction;
[0031] FIG. 3 shows a divergent angle distribution in the axis
symmetric direction and a light intensity distribution of the
luminous bodies in a case where light emitted from the lamp light
source of FIG. 1 and then passed through a polarization converting
system is incident on a fly eye lens;
[0032] FIG. 4 is a perspective view of portions of an illuminating
optical system showing the operation of a reflecting mirror device
according to an embodiment of the present invention;
[0033] FIG. 5 is a cross-sectional view of the reflecting mirror
device of FIG. 4;
[0034] FIG. 6 shows rotation of elliptical light in a double
reflecting mirror;
[0035] FIG. 7A shows the axis rotation of the axis of a divergent
angle when two cylindrical lens arrays are installed in front of
and behind a reflecting mirror device of FIG. 4;
[0036] FIG. 7B shows a divergent angle distribution of light
emitted from a lamp light source and a divergent angle distribution
of light aligned by a reflecting mirror device of FIG. 4;
[0037] FIG. 8 is a diagram that shows that the reflecting mirror
device of FIG. 4 converts circular light emitted from a lamp light
source into elliptical light or near-elliptical light;
[0038] FIG. 9 shows a projection type image display apparatus using
an illuminating optical system with high efficiency according to a
first embodiment of the present invention;
[0039] FIG. 10 shows a projection type image display apparatus
using an illuminating optical system with high efficiency according
to a second embodiment of the present invention;
[0040] FIG. 11 shows a projection type image display apparatus
using an illuminating optical system with high efficiency according
to a third embodiment of the present invention;
[0041] FIG. 12 schematically shows the structure of a spiral lens
usable in the projection type image display apparatus of FIG.
11;
[0042] FIG. 13 is a cross-sectional view of the spiral lens of FIG.
12 showing the lens cells thereof;
[0043] FIG. 14 is a diagram comparing a width of a beam that is
emitted from a light source and incident on a spiral lens without
passing through a first cylindrical lens with a width of a beam
that has been reduced by passing through the first cylindrical lens
and then is incident on the spiral lens of FIG. 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Reference will now be made in detail to the embodiments of
the present invention, examples of which are illustrated in the
accompanying drawings, wherein like reference numerals refer to the
like elements throughout. The embodiments are described below to
explain the present invention by referring to the figures.
[0045] Referring to FIG. 1 which schematically shows a lamp light
source 1 used as a light source of a projection type image display
apparatus, the lamp light source 1 includes a reflecting mirror 3
for traveling light in only one direction. For example, the lamp
light source 1 produces light by arc discharge. A portion of light
generated in an arc discharge region 5' is incident on the
reflecting mirror 3, and the reflecting mirror 3 reflects the light
incident thereon so that the reflected light travels in only one
direction.
[0046] The lamp light source 1 emits approximate parallel light or
approximate converging light according to the shape of the
reflecting mirror 3. For example, if the reflecting mirror 3 is a
parabolic mirror, the lamp light source 1 emits approximate
parallel light. If the reflecting mirror 3 is an elliptical mirror,
the lamp light source 1 emits approximate converging light.
[0047] The arc discharge region 5' has an approximate elliptical
shape, and light generated in the arc discharge region 5' is spread
in all directions. Thus, the arc discharge region 5' operates as an
elliptical luminous body 5.
[0048] Consequently, the lamp light source 1, as shown in FIGS. 2
and 3, emits approximately or substantially circular light 1a' in
which a plurality of luminous bodies 5 having a divergent angle
distribution diverging in an elliptical shape are radially
distributed in an axis symmetric direction. The disposition of the
luminous bodies 5 in the axis symmetric direction indicates that
the luminous bodies 5 are disposed symmetrically with respect to an
optical axis of the circular light 1a'. A main divergent direction
of the luminous bodies 5 is a major axis direction of the
elliptical shape. The major axes of the luminous bodies 5 are
distributed in the axis symmetric direction. In FIG. 2, an arrow
indicated within the luminous bodies 5 denotes the main divergent
direction, that is, the major axis direction.
[0049] As shown in FIGS. 2 and 3, a divergent angle and light
intensity of the luminous bodies 5 are distributed in the axis
symmetric direction due to arc size generated by arc discharge in
the lamp light source 1. A relatively large portion and a
relatively small portion of the divergent angle of the luminous
bodies 5 are approximately in the ratio of 2.5:1.
[0050] FIG. 3 shows the divergent angle distribution and the light
intensity distribution of the luminous bodies 5 in a case where
light emitted from the lamp light source 1 and then passed through
a polarization converting system (not shown) is incident on a fly
eye lens. In FIG. 3, each of the unit cells corresponds to a region
of a one-polarizing beam splitter of the polarization converting
system, and the two unit cells correspond to each lens cell of the
fly eye lens. Here, the polarization converting system aligns the
polarization direction of the circular light 1a' (shown in FIG. 1)
emitted from the lamp light source 1 (shown in FIG. 1) in one
direction. Since such a polarization converting system is known to
those of ordinary skill in the art, a description thereof will be
omitted.
[0051] In consideration of the fact that the approximate circular
light 1a', in which the plurality of elliptical luminous bodies 5
having the divergent angle distribution diverging in the elliptical
shape are distributed in the axis symmetric direction, is emitted
from the lamp light source 1, the illuminating optical system with
high efficiency according to an embodiment of the present invention
is formed to adjust the divergent direction of the circular light
1a' so that the circular light 1a' is converted into elliptical
light or near-elliptical light 1a (shown in FIG. 4). Consequently,
the elliptical light is efficiently matched with components of an
optical system that uses the illuminating optical system with high
efficiency according to the present invention, thereby increasing
the optical efficiency of the optical system.
[0052] FIG. 4 is a perspective view of portions of the illuminating
optical system showing the operation of a reflecting mirror device
according to an embodiment of the present invention
[0053] Referring to FIG. 4, the illuminating optical system
according to the present invention includes the lamp light source 1
and a reflecting mirror device 10 having double reflecting mirror
arrays 11 which are formed in at least a portion of the reflective
mirror device 10.
[0054] The lamp light source 1, as shown in FIGS. 1 through 3,
emits circular light 1a' in which the plurality of elliptical
luminous bodies 5 having the divergent angle distribution with an
elliptical shape are radially distributed in the axis symmetric
direction.
[0055] The reflecting mirror 3 of the lamp light source 1 is a
parabolic mirror that emits parallel light. However, it is to be
understood that the reflecting mirror may be of other shapes.
[0056] The double reflecting mirror arrays 11 are formed in at
least a portion of the reflecting mirror device 10 in order to
adjust the divergent direction of at least a portion of the
circular light 1a' and thus increase the optical efficiency of the
system.
[0057] The reflecting mirror device 10 includes first through
fourth reflecting regions 10a, 10b, 10c, and 10d which are disposed
in a rotational direction thereof. The double reflecting mirror
arrays 11 are formed in the second and fourth reflecting regions
10b and 10d (or the first and third reflecting regions 10a and
10c). In FIG. 4, the double reflecting mirror arrays 11 are formed
in the second and fourth reflecting regions 10b and 10d, and the
first and third reflecting regions 10a and 10c are flat or
substantially flat mirror surfaces.
[0058] The rotational direction may be the counterclockwise
direction or the clockwise direction. Since the first through
fourth reflecting regions 10a, 10b, 10c, and 10d are disposed in
the rotational direction, the first through fourth reflecting
regions 10a, 10b, 10c, and 10d have a 2.times.2 matrix disposition,
and the disposition order of the first through fourth reflecting
regions 10a, 10b, 10c, and 10d is identified with the rotational
direction.
[0059] The mirror surfaces 11a of the double reflecting mirror
arrays 11, as shown in FIG. 5, make an angle of about 45.degree.
with a plane of the reflecting mirror device 10, for example, a
surface of the first and third reflecting regions 10a and 10c in
which the double reflecting mirror arrays 11 are not formed. Thus,
the mirror surfaces 11a are of a so-called "sawtooth"
configuration. However, it is to be understood that other
configurations are possible.
[0060] When the reflecting mirror device 10 according to an
embodiment of the present invention as above described is used, it
is possible that the major axis direction, that is, the divergent
direction of the luminous bodies 5 having the divergent angle
distribution diverging in the elliptical shape are distributed in
the axis symmetric direction, is somewhat aligned toward one
direction using the reflecting mirror device 10.
[0061] FIG. 6 shows a rotation of elliptical light 21 in a double
reflecting mirror 20.
[0062] As shown in FIG. 6, if an axis direction 23 of the
elliptical light 21 is not identical to the direction of an axis 25
dividing mirror surfaces 22a and 22b of the double reflecting
mirror 20, the elliptical light 21 is incident on the double
reflecting mirror 20 and reflected twice by the double reflecting
mirror 20 so that the axis direction 23 of the elliptical light 21
is rotated two times the angular difference between the axis
direction 23 and the direction of the axis 25.
[0063] Accordingly, when a longitudinal direction 13 of the double
reflecting mirror array 11, which is in the reflecting mirror
device 10 according to an embodiment of the present invention as
shown in FIGS. 7A and 7B, is in the middle between a direction for
aligning an axis of a divergent angle of light and an axis
direction of the elliptical divergent angle of the luminous body 5
having the elliptical divergent angle distribution, then a portion
of the divergent angle distribution in the axis symmetric direction
is aligned in one direction so that a shape of light passing
through the reflecting mirror device 10 may be elliptical or near
to elliptical.
[0064] FIG. 7A shows the rotation of the axes of the divergent
angles of the light when cylindrical lens arrays 17 and 19 are
installed in front of and behind the reflecting mirror device 10
according to the present invention.
[0065] FIG. 7B shows a divergent angle distribution of the light
emitted from the lamp light source 1 (shown in FIG. 4) and a
divergent angle distribution of light aligned by the reflecting
mirror device 10 (shown in FIG. 4) according to an embodiment of
the present invention.
[0066] When the divergent angle of the light 1a' emitted from the
lamp light source 1 is adjusted by the reflecting mirror device 10,
a light spot having a longish elliptical shape can be formed as
shown in FIG. 8. FIG. 8 is a diagram confirming that the reflecting
mirror device 10 according to an embodiment of the present
invention converts the circular light emitted from the lamp light
source 1 into the elliptical light or near-elliptical light 1a. In
FIG. 8, light 1a passing through the reflecting mirror device 10 is
condensed by a predetermined lens 27 and forms a light spot.
[0067] Since the circular light 1a' emitted from the lamp light
source 1 is converted into the elliptical light or near-elliptical
light 1a by the illuminating optical system according to an
embodiment of the present invention, the elliptical light 1a is
efficiently matched with components of a projection type image
display apparatus that have a rectangular shape, for example, a fly
eye lens or a glass rod, thereby increasing the optical
efficiency.
[0068] Thus, the projection type image display apparatus is
disposed such that the major axis direction of the light 1a in
which the divergent direction is adjusted by the reflecting mirror
device 10 and converted into elliptical light or near-elliptical
light is identical to the direction of a wide width of any
component of the illuminating optical system or the projection type
image display apparatus, for example, a rectangular fly eye lens or
a glass rod.
[0069] FIG. 9 shows a projection type image display apparatus using
an illuminating optical system with high efficiency according to a
first embodiment of the present invention.
[0070] Referring to FIG. 9, the projection type image display
apparatus includes an illuminating optical system 30, a glass rod
33 used as a light mixture device, and a light valve 37. The
projection type image display apparatus further includes a
condensing lens 31 and a relay lens 35. As described above, the
illuminating optical system 30 includes a lamp light source 1 and a
reflecting mirror device 10 for adjusting a divergent direction of
light emitted from the lamp light source 1.
[0071] Substantially circular light 1a' emitted from the lamp light
source 1 is incident on the reflecting mirror device 10. The
divergent direction of the incident light is adjusted into
elliptical or substantially elliptical light 1a and reflected
toward a condensing lens. After the condensing lens 31 condenses
light reflected by reflecting mirror device 10, the light is
incident on the glass rod 33.
[0072] At this time, since the illuminating optical system 30
adjusts a divergent direction of the circular light 1a' emitted
from the lamp light source 1 so that the circular light 1a' is
converted into the elliptical or near-elliptical light 1a, the
condensing lens 31 condenses the converted elliptical light 1a and
a long elliptical light spot is formed.
[0073] The illuminating optical system 30 is optically aligned such
that the major axis of the elliptical light spot is formed in line
with the long side (the longitudinal axis) of an incident surface
of the glass rod 33. In this case, the elliptical light 1a emitted
from the illuminating optical system 30 is efficiently matched with
the glass rod 33, thereby increasing the optical efficiency.
However, it is to be understood that other orientations of the
illuminating optical system 30 and the glass rod 33 are
possible.
[0074] The glass rod 33 makes the distribution of the incident
light 1a uniform and then outputs the uniform light. The relay lens
35 transfers the uniform light to the light valve 37.
[0075] The light valve 37 controls the incident light on a
pixel-by-pixel basis according to an input image signal and forms
an image.
[0076] The image formed by the light valve 37 is magnified by a
projection lens unit (not shown) and projected on a screen (not
shown).
[0077] As described above, the structure of the optical system
which forms an image and projects the formed image may be modified
variously. Since an image forming/projecting part used in the
projection type image display apparatus that includes a light
mixture device is known to those of ordinary skill in the art, a
description thereof will be omitted.
[0078] Also, the structure of other optical components except for
the illuminating optical system 30 of the projection type image
display apparatus according to the first embodiment of the present
invention and the light mixture device may be modified
variously.
[0079] FIG. 10 shows a projection type image display apparatus
using a highly efficient illuminating optical system according to a
second embodiment the present invention.
[0080] The projection type image display apparatus according to the
second embodiment of the present invention has the same optical
structure as that of the projection type image display apparatus
according to the first embodiment of the present invention shown in
FIG. 9, except that two fly eye lenses 41 and 43 instead of a glass
rod are used as a light mixture device. In FIG. 10, the same
reference numerals as those in FIG. 9 represent the same elements,
and thus their descriptions will be omitted.
[0081] When the fly eye lenses 41 and 43 are used as a light
mixture device in the second embodiment of the present invention, a
section area of the fly eye lenses 41 and 43 is greater than that
of the glass rod used as a light mixture device in the first
embodiment shown in FIG. 9, and thus a condensing lens 31 (refer to
FIG. 9) can be advantageously omitted.
[0082] In order to efficiently match light emitted from the
illuminating optical system 30 with the fly eye lenses 41 and 43
used as a light mixture device, the illuminating optical system 30
is optically aligned such that the major axis of the elliptical or
near-elliptical light 1a emitted from the illuminating optical
system 30 is formed in a line with a long side of the fly eye
lenses 41 and 43. However, it is to be understood that other
orientations of the illuminating optical system 30 and the fly eye
lenses 41 and 43 are possible.
[0083] The optical structure of the projection type image display
apparatus according to the second embodiment of the present
invention which forms an image on a light valve 37 and projects the
formed image may be variously modified.
[0084] The illuminating optical system according to the present
invention, as shown in FIG. 11, can be applied to a single-panel
color image display apparatus including a colored light separator
having three or more dichroic filters.
[0085] FIG. 11 shows a single-panel color image display apparatus
using a highly efficient illuminating optical system according to a
third the present invention.
[0086] Referring to FIG. 11, the single-panel color image display
apparatus according to the third embodiment of the present
invention includes an illuminating optical system 30, a colored
light separator 120 which separates light emitted from a lamp light
source 1 according to color (i.e., by wavelength A ranges
corresponding to different colors), and a light valve 140 which
controls incident light on a pixel-by-pixel basis according to an
input image signal and forms a color image. That is, the
single-panel color image display apparatus forms a color image
using the single light valve 140.
[0087] As described above, the illuminating optical system 30
adjusts a divergent direction of light 1a' emitted from the lamp
light source 1 by a reflecting mirror device 10 in which double
reflecting mirror arrays 11 are formed in a portion thereof so that
the circular light 1a' is converted into elliptical or
near-elliptical light 1a.
[0088] The colored light separator 120 includes three or more
dichroic filters to separate the light 1a emitted from the
illuminating optical system 30 according to wavelength.
Specifically, the colored light separator 120 includes first,
second, and third dichroic filters 120B, 120G, and 120R of a
reflective type. The dichroic filters 120B, 120G, and 120R reflect
a blue light B, a green light G, and a red light R, respectively,
and transmit other colored light.
[0089] When light emitted from the illuminating optical system 30,
which light is white (i.e., comprising a broad spectrum of
wavelengths), is incident on the colored light separator 120 having
the first, second, and third dichroic filters 120B, 120G, and 120R,
the first dichroic filter 120B reflects a blue light B from the
incident white light and transmits remaining light. The second
dichroic filter 120G reflects a green light G from the light
transmitted by the first dichroic filter 120B and transmits a
remaining beam, that is, a red light R. The third dichroic filter
120R reflects the red light R transmitted by the second dichroic
filter 120G.
[0090] Here, a disposition order of the first, second, and third
dichroic filters 120B, 120G, and 120R can be changed variously.
[0091] The first, second, and third dichroic filters 120B, 120G,
and 120R are disposed such that the blue light B, the green light
G, and the red light R separated by the colored light separator 120
are incident on the same lens cell of a first fly eye lens 131
without color mixture among the B, G, and R colored light.
[0092] In FIG. 11, the first, second, and third dichroic filters
120B, 120G, and 120R of the colored light separator 120 are
disposed in parallel to one another. However, it is to be
understood that other arrangements are possible.
[0093] The single-panel color image display apparatus according to
the third embodiment of the present invention is shown to include
an optional a structure for using a color scrolling technique.
Using the color scrolling technique, the single-panel color image
display apparatus according to the present invention can have the
same optical efficiency as that of a three-panel color image
display apparatus.
[0094] According to the color scrolling technique, white light is
separated into a plurality of colored light beams and the plurality
of colored light beams are simultaneously sent at different
locations on a light valve, thereby forming a plurality of color
bars and the color bars move at a constant speed in a particular
method so that an image is formed after all the plurality of color
bars for each pixel reach the light valve.
[0095] One example of such a scrolling arrangement includes a
spiral lens 110 in order to perform a color scrolling.
[0096] First and second fly eye lenses 131 and 135 are further
provided along the optical path between the spiral lens 110 and the
light valve 140. Also, a relay lens 137 is further provided between
the second fly eye lens 135 and the light valve 140.
[0097] The spiral lens 110, as shown in FIG. 12, has a disc
structure in which the array of lens cells 111 is spirally formed
in order to obtain the effect of a rectilinear motion of the lens
array 111 during the rotation of the spiral lens 110. That is, the
rotation of the spiral lens 110 simulates rectilinear motion of the
scrolling arrangement. As shown in FIG. 12, the lens cells 111 are
formed at regular intervals and have the same cross-section.
However, it is to be understood that other configurations are
possible.
[0098] For example, the lens cells 111 of the spiral lens 110, as
shown in FIG. 13, may be cylindrical lens cells whose cross-section
shapes are arcs. Alternatively, the lens cells 111 of the spiral
lens 110 can be either a diffractive optical element or a hologram
optical element.
[0099] Each of the lens cells 111 of the spiral lens 110 operates
as a condensing lens for condensing the light 1a emitted from the
illuminating optical system 30.
[0100] When the spiral lens 110 having the spiral lens cell array
is rotated, the rotation of the spiral lens cell array makes the
effect of a rectilinear motion of the lens array so that color
scrolling is performed.
[0101] In other words, since the array of lens cells 111 is formed
spirally, when the spiral lens 110 rotates at a constant speed, it
can be seen from the viewpoint of a light beam passing through a
predetermined location of the spiral lens 110 that the effect
generated when a cylindrical lens array continuously moves upward
or downward at a constant speed is obtained from the spiral lens
cell array. Here, when a light beam L passing through the spiral
lens 110 has a narrow width, the effect of the light beam L passing
through the cylindrical lens array that moves rectilinearly can be
obtained from the light beam passing through the spiral lens
110.
[0102] Accordingly, as the spiral lens 110 rotates at a constant
speed, the beams of colored light separated by the colored light
separator 120 are repeatedly scrolled according to the rotation of
the spiral lens 110 so that color bars formed on the light valve
140 are scrolled.
[0103] At this time, in a case where the spiral lens 110 is
provided as described above, since the spiral lens 110 continuously
rotates in one direction without changing the rotational direction
so that the color scrolling is performed, continuity and
consistency of the color scrolling can be guaranteed. In addition,
since color bars are scrolled using the single spiral lens 110, the
scrolling speed of the color bars is advantageously kept
constant.
[0104] Here, the number of spiral lens cells 111 on the spiral lens
110 or the rotation speed of the spiral lens 110 can be adjusted to
synchronize with the operating frequency of the light valve
140.
[0105] For example, if the operating frequency of the light valve
140 is high, more lens cells are included so that the scrolling
speed can be adjusted to be faster while keeping the rotation speed
of the spiral lens 110 constant, or the scrolling speed can be
adjusted to be faster by increasing the rotation frequency of the
spiral lens 110 without changing the number of spiral lens cells
111.
[0106] Although the single-panel color image display apparatus
according to the third embodiment of the present invention shown in
FIG. 11 includes the single spiral lens 110, two spiral lenses may
be provided. In a case where the single-panel color image display
apparatus includes two spiral lenses, the two spiral lenses are
installed on the same driving axis so that color scrolling can be
performed. Thus, the speed of the color scrolling can be kept
constant.
[0107] In a case where the dichroic filters 120B, 120G, and 120R of
the colored light separator 120 are parallel to one another, the
spiral lens 110, as shown in FIG. 11, is disposed between the
illuminating optical system 30 and the colored light separator 120
so that light condensed by the spiral lens 110 is separated by the
colored light separator 120 and then, the separated color beams are
not mixed due to difference in the lengths of optical paths of the
color beams caused by the selective reflection of the dichroic
filters 120B, 120G, and 120R, and are incident on the first fly eye
lens 131. However, it is to be understood that other arrangements
are possible.
[0108] For example, dichroic filters 120B, 120G, and 120R of the
colored light separator 120 may be disposed aslant with respect to
one another and the spiral lens 110 may be disposed between the
colored light separator 120 and the light valve 140.
[0109] Lens cells of each of the first and second fly eye lenses
131 and 135 match with each other in a one-to-one correspondence.
Further, the lens cells of the first and second fly eye lenses 131
and 135 match the lens cells 111 of the spiral lens 110 in a
one-to-one correspondence.
[0110] As illustrated in FIG. 11, the first fly eye lens 131 is
disposed on a focal surface of the spiral lens 110 in order to
condense the colored light which passes through the spiral lens 110
and are separated by the colored light separator 120 without color
mixture among the colored light. However, it is to be understood
that the fly eye lens 131 may be positioned elsewhere.
[0111] In this case, the color beams, which are condensed by the
lens cells 111 of the spiral lens 110 that functions as a
condensing lens and separated by the dichroic filters 120B, 120G,
and 120R of the colored light separator 120, have different lengths
of their optical paths due to the dichroic filters 120B, 120G, and
120R which are separated from one another, thereby focusing at
different locations of the lens cell of the first lens array
131.
[0112] Color beams passing through the first fly eye lens 131 are
converted into divergent light and are incident on the second fly
eye lens 135 in a combined state. The second fly eye lens 135
converts the incident beam into parallel light.
[0113] The parallel color beams passing through the first and
second fly eye lenses 131 and 135 are incident at different
locations on the light valve 140 by the relay lens 137, thereby
forming color bars. The relay lens 137 may be constituted of a
single lens as shown in FIG. 11, or the relay lens 137 may be
constituted of a lens group including two or more lenses.
[0114] In a case where the first and second fly eye lenses 131 and
135 and the relay lens 137 are provided, light condensed by the
spiral lens 110 is transferred by the first and second fly eye
lenses 131 and 135 in a one-to-one correspondence and individual
color bars are formed on the light valve 140 by the relay lens
137.
[0115] The light valve 140 controls the color beams irradiated, for
example, in a form of R, G, and B color bars according to an input
image signal, thereby forming a color image.
[0116] The R, G, and B color bars formed on the light valve 140 are
scrolled according to the rotation of the spiral lens 110. Thus,
the light valve 140 processes image information for each pixel to
synchronize with the movement of the R, G, and B color bars,
thereby forming a color image. The color image formed by the light
valve 140 is magnified by a projecting lens unit (not shown) and
lands on a screen (not shown).
[0117] The single-panel color image display apparatus according to
the third embodiment of the present invention is shown to further
include optional first and second cylindrical lenses 105 and 107
which are disposed in front of and behind the spiral lens 110,
respectively, so as to adjust a width of the light 1a incident on
the spiral lens 110.
[0118] To increase optical efficiency, the major axis direction of
the elliptical or near-elliptical light 1a emitted from the
illuminating optical system 30 is in line with the longitudinal
direction of the first cylindrical lens 105.
[0119] The first cylindrical lens 105 reduces the width of the
light 1a emitted from the illuminating optical system 30 so that
the light 1a with the reduced width is incident on the spiral lens
110. The second cylindrical lens 107 returns the reduced width of
the light 1a passing through the spiral lens 110 to its original
width.
[0120] Referring to FIG. 14, the light 1a which is emitted from the
illuminating optical system 30 and incident on the spiral lens 110
without passing through the first cylindrical lens 105 is compared
to the light 1a which is emitted from the illuminating optical
system 30, has a width reduced by the first cylindrical lens 105
and then is incident on the spiral lens 110.
[0121] As shown in a left portion of FIG. 14, when a width of a
light beam L' which is emitted from the illuminating optical system
30 and incident on the spiral lens 110 without passing through the
first cylindrical lens 105 is relatively wide, the shape of the
light beam L' does not match the shape of the lens cells well due
to the spiral shape of the lens cells 111 of the spiral lens 110,
and thus, light loss is caused.
[0122] As shown in a right portion of FIG. 14, when a width of a
light beam L is reduced using the first cylindrical lens 105, the
light beam L with the reduced width passes through the spiral lens
110 so that the shape of the light beam L nearly matches the spiral
shape of the lens cells 111 of the spiral lens 110, thereby
reducing light loss.
[0123] As described above, since a width of beam can be adjusted
using the two cylindrical lenses 105 and 107, light loss can be
reduced.
[0124] As described above, since a divergent direction of light
emitted from a lamp light source can be adjusted at least partly
using a reflecting mirror device in which reflecting mirror arrays
are formed in at least a portion, an illuminating optical system
can effectively match other optical components of a projection type
image display apparatus using the same, thereby increasing the
optical efficiency of the projection type image display
apparatus.
[0125] Although a few embodiments of the present invention have
been shown and described, the present invention is not limited to
the disclosed embodiments. Rather, it would be appreciated by those
skilled in the art that changes may be made in this embodiment
without departing from the principles and spirit of the invention,
the scope of which is defined by the claims and their
equivalents.
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