U.S. patent application number 11/366369 was filed with the patent office on 2006-09-21 for image projection apparatus having an elevation adjustment mechanism with memory.
Invention is credited to Hirohisa Ishino.
Application Number | 20060209272 11/366369 |
Document ID | / |
Family ID | 29727707 |
Filed Date | 2006-09-21 |
United States Patent
Application |
20060209272 |
Kind Code |
A1 |
Ishino; Hirohisa |
September 21, 2006 |
IMAGE PROJECTION APPARATUS HAVING AN ELEVATION ADJUSTMENT MECHANISM
WITH MEMORY
Abstract
An image projection apparatus having an adjuster mechanism with
a projecting member projecting from a bottom surface of the case to
adjust the elevation angle of a projection lens and an
opening/closing member located at a front surface of said
projection lens for opening or closing the projection opening. The
adjuster mechanism uses an electric motor to move the projecting
member up and down. The opening/closing member is opened/closed
using a linkage mechanism linked to the adjuster mechanism.
Inventors: |
Ishino; Hirohisa; (Kanagawa,
JP) |
Correspondence
Address: |
FROMMER LAWRENCE & HAUG
745 FIFTH AVENUE- 10TH FL.
NEW YORK
NY
10151
US
|
Family ID: |
29727707 |
Appl. No.: |
11/366369 |
Filed: |
March 2, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10486146 |
Feb 6, 2004 |
7021773 |
|
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PCT/JP03/07376 |
Jun 10, 2003 |
|
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11366369 |
Mar 2, 2006 |
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Current U.S.
Class: |
353/119 ;
348/E5.143; 353/70 |
Current CPC
Class: |
H04N 9/3141 20130101;
G03B 21/006 20130101; G03B 21/145 20130101; G03B 23/00
20130101 |
Class at
Publication: |
353/119 ;
353/070 |
International
Class: |
G03B 21/22 20060101
G03B021/22 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 10, 2002 |
JP |
2002-168939 |
Claims
1-15. (canceled)
16. Image projection apparatus comprising: a case having first and
second opposite sides and top and bottom portions, said case having
a projection opening on a first side; a projection lens projecting
an image from the projection opening of said case; an adjuster
having an elevation member, said adjuster being driven to lift said
elevation member and adjust an elevation angle of said projection
lens by using the bottom portion of said case as a fulcrum, said
bottom portion being closer to said second side than the first side
of said case; a driver controller for controllably driving said
adjuster; and a memory for storing the adjusted elevation angle or
the elevation position of said elevation member, wherein said drive
controller drives said adjuster such that the adjuster returns to
the elevation angle or the elevation position of said elevation
member stored in said memory when power to said image projection
apparatus is turned on.
17. The image projection apparatus of claim 16, wherein said driver
controller controls drives said adjuster to return said elevation
member to a non-elevating state when power is turned off.
18. The image projection apparatus of claim 16, further comprising
a position detector for detecting the elevation position of said
elevation member; and wherein said drive controller controls said
adjuster in accordance with a detected value of said position
detector.
19. The image projection apparatus of claim 16, wherein said
adjuster operates to lift said elevation member from a first
position, where a lower end of the elevation member does not
contact a support surface for the bottom of said case, through a
second position where the lower end of said elevation member
contacts said support surface and raises the first side of said
case, thereby generating an elevation angle, to a third position
for further enlarging the elevation angle exceeding the elevation
angle at said second position, whereby the elevation angle of said
projection lens is adjusted in accordance with said elevation.
20. The image projection apparatus of claim 19, wherein said drive
controller drives said adjuster to return said elevation member to
said first position when power is turned off.
21. The image projection apparatus of claim 16, further comprising
elevation instruction buttons provided on a top surface or a side
surface of said case proximate said second side and in the vicinity
of said fulcrum and operable to adjust the elevation of said
elevation member.
Description
[0001] This is a continuation of application Ser. No. 10/486,146,
filed Feb. 6, 2004, which is a 371 of International Application
PCT/JP03/07376, filed Jun. 10, 2003, with a claim of priority to
Japanese Application 2002-168939, filed in Japan on Jun. 10, 2002,
all of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to an image projection
apparatus provided with an adjuster for adjusting a degree of
elevation of a projected image.
BACKGROUND ART
[0003] In liquid crystal projectors and other image projection
apparatuses having video modulating means, an image projection
apparatus provided with an adjuster for adjusting the degree of
elevation of the apparatus in order to adjust the height of the
projected image on the screen has been known. The adjuster is
usually operated manually.
[0004] In an image projection apparatus provided with an adjuster,
however, when adjusting the height of the projected image on the
screen, it is necessary to tilt the image projection apparatus and
view the image on the screen while adjusting the amount of the
height of the adjuster, so there were the disadvantages that the
operation was difficult and fine adjustment was hard.
[0005] Further, there was also the disadvantages that whenever the
position of the screen was changed, adjustment of the degree of
elevation of the image projection apparatus was necessary, a long
time was needed for the settings for projecting the image onto the
screen from the image projection apparatus, and also storage of the
adjuster into the case was troublesome.
[0006] On the other hand, the projection lens of an image
projection apparatus is an optical lens, so care must be taken so
as not to scratch or dirty it. Therefore, many image projection
apparatuses provide lens caps on the projection lenses for
protection. For this reason, in order to project an image onto a
screen from the image projection apparatus, detachment of the lens
cap was necessary every time. On this point as well, there existed
the disadvantages that a long time was needed for the settings and
also storage of the adjuster into the case was troublesome.
DISCLOSURE OF THE INVENTION
[0007] An object of the present invention is to provide an image
projection apparatus having an adjuster able to adjust the degree
of elevation which can easily perform adjustment for projecting an
image onto a screen and can easily return a projecting member or
other elevation member to a return position (first position).
[0008] Another object of the present invention is to provide an
image projection apparatus able to effectively protect the
projection lens.
[0009] According to the first aspect of the present invention,
there is provided an image projection apparatus comprising a case
having a projection opening at a first side; a projection lens
contained in said case and projecting an image through the
projection opening of said case; an adjuster means having an
elevation member, lifting said elevation member from a first
position where a lower end of the elevation member does not contact
a setting surface of the bottom of said case, through a second
position where the lower end of said elevation member contacts the
setting surface of said case and raises a first side of said case
by using a bottom of said case on a second side facing the first
side of said case as a fulcrum and starts generation of an
elevation angle, to a third position for further enlarging the
elevation angle over that of said second position, and adjusting
the elevation angle of said projection lens in accordance with this
elevation; a drive control means for controlling the drive of said
adjuster means; an opening/closing member located at a front
surface of said projection lens for opening or closing said
projection opening; and a linkage means operating linked with said
adjuster means to move said opening/closing member so as to open
said projection opening during a period where said elevation member
is moved from said first position to said third position by said
drive control means to move said opening/closing member so as to
close said projection opening when said elevation member returns
from said third position to said first position.
[0010] According to a second aspect of the present invention, there
is provided an image projection apparatus comprising a case having
a projection opening at a first side; a projection lens contained
in said case and projecting an image through the projection opening
of said case; an adjuster means having an elevation member, lifting
said elevation member from a first position where a lower end of
the elevation member does not contact a setting surface of the
bottom of said case, through a second position where the lower end
of said elevation member contacts the setting surface of said case
and raises a first side of said case by using a bottom of said case
on a second side facing the first side of said case as a fulcrum
and starts generation of an elevation angle, to a third position
for further enlarging the elevation angle exceeding that of the
second position and adjusting the elevation angle of said
projection lens in accordance with this elevation; a drive control
means for controlling the drive of said adjuster means; and
elevation instruction buttons provided on a top surface or a side
surface of said case at a second side of said case in the vicinity
of said fulcrum and instrucing elevation of said elevation
member.
[0011] According to the third aspect of the present invention,
there is provided an image projection apparatus comprising a case
having a projection opening on a first side; a projection lens
contained in said case and projecting an image through the
projection opening of said case; an adjuster means having an
elevation member, lifting said elevation member from a first
position where a lower end of the elevation member does not contact
a setting surface of the bottom of said case, through a second
position where the lower end of said elevation member contacts the
setting surface of said case and raises the first side of said case
by using a bottom of said case on a second side facing the first
side of said case as a fulcrum, and starts generation of an
elevation angle, to a third position for further enlarging the
elevation angle exceeding that of the second position, and
adjusting the elevation angle of said projection lens in accordance
with this elevation; a drive control means for controlling the
drive of said adjuster means; a position detecting means for
detecting the elevation position of said elevation member; and a
storage means for storing the adjusted or set elevation angle or
the elevation position of said elevation member, wherein said drive
control means controls the drive of said adjuster means with
reference to a detected value of said position detecting means so
that it returns to the elevation angle or the elevation position of
said elevation member stored in said storage means.
BRIEF DESCRIPTION OF THE INVENTION
[0012] FIG. 1 is a perspective view of the appearance of an image
projection apparatus according to an embodiment of the present
invention.
[0013] FIG. 2 is a perspective view of a state where the image
projection apparatus projects an image.
[0014] FIG. 3 is a view for explaining an example of adjustment
work of an elevation angle of an image projection apparatus.
[0015] FIG. 4 is a view of a schematic configuration of an inside
of an image projection apparatus.
[0016] FIG. 5 is a perspective view of the structure of a movement
mechanism and a linkage mechanism.
[0017] FIG. 6 is a view for explaining the operation of the linkage
mechanism.
[0018] FIG. 7 is a flow chart of an example of a series of
operations from turning on power of the image projection apparatus
to shutting off the power.
BEST MODE FOR WORKING THE INVENTION
[0019] Below, an explanation will be given of an embodiment of an
image projection apparatus of the present invention with reference
to the drawings.
[0020] FIG. 1 is a perspective view of the appearance of an image
projection apparatus according to an embodiment of the present
invention. FIG. 2 is a perspective view of a state where an image
projection apparatus 1 projects an image.
[0021] As shown in FIG. 1, the image projection apparatus 1 is
placed on a desk or other base BS corresponding to the setting
surface of the present invention. A front surface 2a of a case 2 is
provided with a projection opening 2h. This projection opening 2h
is opened or closed by an opening/closing plate 3.
[0022] A top surface 2b of the case 2 is provided with two
elevation instruction buttons 5a and 5b and a power switch 6. These
elevation instruction buttons 5a and 5b and the power switch 6,
from the viewpoint of operability, are arranged in the vicinity of
a back surface 2c of the case 2 where there is a little position
fluctuation even by the elevation angle control explained
later.
[0023] A bottom surface 2d of the case 2 is provided with two
support members 11 at the front surface 2a side. The back surface
side 2c is provided with support members 12. The case 2 is
supported at 4 points by these support members 11 and 12. A
clearance is formed between the base BS and the bottom surface 2d
of the case 2.
[0024] As shown in FIG. 2, the image projection apparatus 1 has a
projecting member 20 serving as the elevation member of the present
invention. The projecting member 20 can be elevated (moved up and
down) between an accommodation position inside the case 2 as an
example of a first position (return position) of the elevation
member of the present invention and a position where the lower end
of the projecting member 20 abuts against the base BS and the
elevation angle for inclining the case 2 starts to be generated as
a second position of the present invention and further a third
position where the projecting member 20 projectes from the bottom
surface 2d of the case 2 and the elevation angle of the case 2
becomes larger up to the maximum elevation angle. Note that the
accommodation position does not have to be a position where the
entire projecting member 20 is accommodated in the case 2 and may
be a position where the lower end of the projecting member 20 does
not abut against the base BS and does not generate an elevation
angle.
[0025] When the projecting member 20 is located at the
accommodation position inside the case 2, the image projection
apparatus 1 is located in a horizontal direction parallel to the
base BS. By the projection of the projecting member 20 from the
bottom surface 2d of the case 2, the elevation angle of the image
projection apparatus 1 changes in accordance with the projection
amount thereof. The elevation angle of the projected image
projected from the projection opening 2h onto the screen changes in
accordance with the change of this elevation angle.
[0026] The elevation instruction buttons 5a and 5b are instruction
buttons for adjusting the elevation position of the projecting
member 20. For example, when the elevation instruction button 5b is
depressed, during the depression, by the control operation of a
control means 30 mentioned later, for example, the projecting
member 20 moves downward from the accommodation position serving as
the first position toward the second position where the elevation
angle is generated. It projects from the bottom surface 2d of the
case 2 and abuts against the base BS. When the projecting member 20
further continues to move downward, the bottom of the back surface
(rear surface) 2c facing the front surface 2a of the case 2 tilts
about the axis S using the axis S passing through the support
members 12 as a fulcrum, whereby the front surface 2a provided with
the projection opening 2h of the case 2 rises. When continuing to
depress the elevation instruction button 5b, the projecting member
20 moves up to the third position where the maximum elevation angle
is generated and stops.
[0027] On the other hand, when depressing the elevation instruction
button 5a, the projecting member 20 rises toward the accommodation
position. When the projecting member 20 rises from the base BS, the
front surface 2a of the case 2 moves down. Finally, the inclination
of the image projection apparatus 1 disappears. When the projecting
member 20 further rises, it returns to the accommodation
position.
[0028] The opening/closing plate 3 is moved linked with the
elevation of this projecting member 20 to open the projection
opening 2h. Image light L from the projection lens 38 (FIG. 4) is
projected onto the screen through the projection opening 2h. Note
that the opening/closing plate 3 is automatically opened or closed
as will be mentioned later. The opening/closing structure of this
opening/closing plate 3 and the internal structure of the image
projection apparatus 1 will be explained later.
[0029] FIGS. 3A and 3B are views for explaining an example of the
adjustment work of the elevation angle of the image projection
apparatus 1.
[0030] As shown in FIGS. 3A and 3B, the elevation angle e is
defined as an angle formed by for example the base BS and a light
axis L.sub.0 of the projection lens using the base BS as the
reference. Alternatively, it is defined as an angle formed by the
base BS and the lowermost portion of the image light L. Note that
the elevation angle .theta. is substantially equal to the
inclination angle of the case 2 with respect to the base BS.
[0031] The height on the screen SC of the image light L projected
from the image projection apparatus 1 is adjusted by operating the
elevation instruction buttons 5a and 5b to adjust the elevation
angle .theta..
[0032] The elevation instruction buttons 5a and 5b are located
above the axis S passing through the support members 12, therefore
the image projected on the screen SC can be viewed while operating
the elevation instruction buttons 5a and 5b. Further, even if the
image projection apparatus 1 is inclined, as seen from FIG. 3B, the
positions of the elevation instruction buttons 5a and 5b do not
move much at all, so the operability of the elevation instruction
buttons 5a and 5b is very good.
[0033] In the same way as above, the power switch 6 is also located
in the vicinity of the elevation instruction buttons 5a and 5b. The
operability is good for the same reason as that for the elevation
instruction buttons 5a and 5b.
[0034] FIG. 4 is a view of the schematic configuration of the
inside of the image projection apparatus 1.
[0035] As shown in FIG. 4, the image projection apparatus 1 has a
control device 30, an amplifier circuit 33, an electric motor 51, a
drive circuit 34, a lamp power supply 35, a lamp 36, an LCD panel
37, a projection lens 38, an adjuster mechanism 50, a linkage
mechanism 60 linking with the adjuster mechanism 50, and a position
detector 70.
[0036] The drive circuit 34 receives a video signal from an input
terminal 45 and drives the LCD panel 37 based on this video
signal.
[0037] The LCD panel 37 acts as a video signal modulating means for
generating an image to be projected onto the screen SC and making
it incident upon the projection lens 38.
[0038] The lamp 36 outputs light for projecting the image generated
at the LCD panel 37 via the projection lens 38 onto the screen
SC.
[0039] The lamp power supply 35 supplies electric power to the lamp
36 in accordance with the control signal from the control device
30.
[0040] The projection lens 38 magnifies and emits the light from
the lamp 36 modulated by the LCD panel 37 based on the video signal
and focuses it on the screen SC. The opening/closing plate 3
described above is arranged at the projection opening 2h portion of
the front surface of this projection lens 38. When a video image is
not projected from the projection lens 38, the opening/closing
plate 3 closes the projection opening 2ha and covers the front
surface of the projection lens 38 to protect the projection lens 38
from scratches, dirt, etc.
[0041] The position detector 70 detects the position of the
projecting member 20 as will be explained later. As this position
detector 70, use is made of for example a slide type
potentiometer.
[0042] The control device 30 has a processor 31 having a CPU and a
memory 32. The processor 31 performs various operations and the
memory 32 stores various data.
[0043] The control device 30 receives as input a detection signal
70s of the position detector 70, an on/off signal 6s from the power
switch 6, and instruction signals 5as and 5bs of the operation
buttons 5a and 5b and performs the on/off control of the lamp power
supply 35 and the drive control of the electric motor 51 based on
the input signals.
[0044] Concretely, the control device 30 outputs a signal for
operating the lamp power supply 35 to the related lamp power supply
35 where the on/off signal 6s from the power switch 6 is in the on
state, and while outputs a signal for turning off the lamp power
supply 35 to the related lamp power supply 35 where the on/off
signal 6s is in the off state.
[0045] Further, when driving the adjuster mechanism 50 in
accordance with the operation of the elevation instruction buttons
5a and 5b, the control device 30 outputs an instruction 30s1 for
driving the electric motor 51 and an instruction 30s2 for defining
the rotation direction to the amplifier circuit 33. Namely, the
electric motor 51 can rotate forward or reverse and further can
rotate at a rotation speed in accordance with the magnitude of the
drive instruction 30s1. The rotation direction of the electric
motor 51 defines the elevation direction of the projecting member
20, while the rotation speed of the electric motor 51 defines the
elevation speed of the projecting member 20.
[0046] Note that the control device 30, the amplifier circuit 33,
and the electric motor 51 constitute the drive control means of the
present invention. However, the memory in the control device 30
constitutes the storage means of the present invention.
[0047] The amplifier circuit 33 applies a predetermined voltage
having an orientation in accordance with the instruction 30s2 to
the electric motor 51 when for example the instruction 30s1 is at a
low level and does not apply voltage to the electric motor 51 when
the instruction 30s1 is at a high level.
[0048] FIG. 5 is a perspective view of the structure of the
adjuster mechanism 50 and the linkage mechanism 60 linking with the
adjuster mechanism 50.
[0049] As shown in FIG. 5, the adjuster mechanism 50 has a
projecting member 20, a worm gear 52, a gear 53, and a screw shaft
54.
[0050] The worm gear 52 is connected to the output shaft of the
electric motor 51 affixed in the case 2.
[0051] The gear 53 is meshed with the worm gear 52. The center
portion of this gear 53 is inserted in the shaft 54b of the upper
end side of the screw shaft 54, while the gear 53 is fixed to the
shaft 54b.
[0052] The screw shaft 54 is provided with a thread part 54a having
a thread formed on its outer circumference, the front end of the
shaft 54b of this screw shaft 54 is rotatably supported by the
support member 56 fixed in the case 2, and the lower end of the
screw shaft 54 is rotatably supported at the support plate 55 fixed
in the case 2.
[0053] The projecting member 20 has upper and lower ends which are
bent. A screw hole 20h in which the thread part 54a of the screw
shaft 54 is fitted is formed in the upper side bent portion.
[0054] Further, the projecting member 20 is moveably inserted into
a guide hole 55h formed in the support plate 55 and guided in the
elevation direction by this guide hole 55h.
[0055] The projecting member 20 is provided with an arm 20A. The
moveable portion 71 of the position detector 70 is inserted in an
engagement hole 20Ah formed in this arm 20A.
[0056] The position detector 70 is for example a slide type
potentiometer and outputs a voltage signal in accordance with the
position of the moveable portion 71 to the control device 30.
[0057] The linkage mechanism 60 linked with the adjuster mechanism
50 is constituted by a link member 61, an arm 20A of the projecting
member 20, an arm 3b formed at the opening/closing plate 3, and a
resilient member 65.
[0058] The link member 61 is rotatably supported about the support
shaft 69 fixed in the case 2. This link member 61 has an abutment
61a located on one side of the support shaft 69 and abutting
against the tip end of the arm 20A of the projecting member 20 and
a linkage 61b located on the other side of the support shaft 69 and
linked with the arm 3b of the opening/closing plate 3.
[0059] The linkage 61b is formed with a long hole portion 61h into
which a pin 3c provided on the arm 3b of the opening/closing plate
3 is moveably inserted.
[0060] Further, the abutment 61a of the link member 61 abuts
against a stopper 68 fixed in the case 2. The rotation is defined
at the abutment position.
[0061] The resilient member 65 links the linkage 61b of the link
member 61 and the case 2 and biases the link member 61 in the
direction of an arrow shown in FIG. 5. As the resilient member 65,
use is made of for example a coil spring.
[0062] The opening/closing plate 3 has a holder 3a. This holder 3a
is rotatably held about the support shaft 4 fixed in the case
2.
[0063] The holder 3a of the opening/closing plate 3 is formed with
the arm 3b moveably linked with the linkage 61b of the link member
61.
[0064] In the adjuster mechanism 50, when the electric motor 51
rotates, the worm gear 52 rotates, whereby the gear 53 and the
screw shaft 54 rotate.
[0065] When the screw shaft 54 rotates, the projecting member 20
moves in the axial direction of the screw shaft 54 in accordance
with the rotation direction of the screw shaft 54. Accordingly, the
projecting member 20 moves upward or downward by the rotation
operation of the electric motor 51.
[0066] FIG. 6A to FIG. 6C are views for explaining the operation of
the linkage mechanism 60.
[0067] FIG. 6A shows a state where the projecting member 20 is
accommodated in the case 2 and at the predetermined storage
position (the first position of the present invention).
[0068] In this state, the arm 20A of the projecting member 20 abuts
against the abutment 61a of the link member 61. The link member 61
tries to rotate about the support shaft 69 in the direction of an
arrow B1 by a biasing force of the resilient member 65, but the
resilient force of the resilient member 65 is suppressed by the arm
20A, whereby the rotation is limited.
[0069] In the state shown in FIG. 6A, after the power switch 6 is
turned on and power is supplied, when the elevation instruction
button 5b is pushed down to give the instruction "raise the
elevation angle", the control device 30 drives the electric motor
51 and moves the projecting member 20 downward as shown in FIG. 6B.
Along with the downward movement of the arm 20A of the projecting
member 20, the engagement of the arm 20A and the abutment 61a of
the link member 61 is released, and the link member 61 starts the
rotation above the support shaft 69 in the direction of the arrow
B1 by the biasing force of the resilient member 65.
[0070] When the link member 61 rotates, the linkage 61b of the link
member 61 and the arm 3b of the opening/closing plate 3 are
connected, so the opening/closing plate 3 rotates about the support
shaft 4 in the direction of an arrow C1. At this time, the pin 3c
of the arm 3b of the opening/closing plate 3 moves in the long hole
portion 61h of the linkage 61b of the link member 61.
[0071] By the rotation of the opening/closing plate 3 about the
support shaft 4, the projection opening 2h closed by the
opening/closing plate 3 is opened, and the projection lens 38 faces
the projection opening 2h.
[0072] The link member 61 rotates about the support shaft 69 in the
direction of the arrow B1 by the biasing force of the resilient
member 65, but, as shown in FIG. 6B, stops at a position where the
abutment 61a of the link member 61 abuts against the stopper 68.
For this reason, the posture of the link member 61 and the
opening/closing plate 3 is maintained in the state shown in FIG.
6B. In this state, the case 2 is located parallel to the base BS
(elevation angle .theta.=0). Since the projection opening 2h is
opened, the projection image can be projected onto the screen SC in
the state where the elevation angle .theta.=0.
[0073] During the period where the user operates the elevation
instruction button 5a to instruct to move the projecting member 20
upward in the direction enlarging the elevation angle, the control
device 30 drives the electric motor 51 during the period where the
elevation instruction button 5a is depressed. When the projecting
member 20 is further moved downward, the lower end side of the
projecting member 20 projects from an opening 2e formed in the
bottom surface 2d of the case 2. After the lower end of the
projecting member 20 reaches the base BS, when it further continues
to move downward, as shown in FIG. 6C, the front surface 2a side of
the case 2 is pushed up, and the support member 11 moves away from
the base BS.
[0074] By adjusting the position of the projecting member 20 up and
down by the elevation instruction buttons 5a and 5b, the
inclination angle (elevation angle .theta.) of the case 2 can be
adjusted.
[0075] Next, an explanation will be given of an example of the
series of operations from turning on the power of the image
projection apparatus 1 having the above configuration to shutting
off the power supply with reference to FIG. 7.
[0076] FIG. 7 is a flow chart of an example of the series of
operations from turning on the power of the image projection
apparatus 1 to shutting off the power.
[0077] First, the power switch 6 provided on the upper surface 2b
of the case 2 is operated to supply electric power to the image
projection apparatus 1 (step S1).
[0078] The control device 30 activates the lamp power supply 35
when the on signal 6s is input from the power switch 6 (step
S2).
[0079] Further, the processor 31 of the control device 30 reads the
position information of the projecting member 20 stored in the
memory 32 (step S3). Note that the position information of the
projecting member 20 stored in the memory 32 is the position
information of the projecting member 20 detected by the position
detector 70 at the previous shut off of the power.
[0080] The control device 30 outputs the instruction 30s1 for
driving the electric motor 51 and the instruction 30s2 for defining
the rotation direction to the amplifier circuit 33 based on the
read position information of the projecting member 20.
[0081] By this, the projecting member 20 starts downward movement
from the predetermined storage position (step S4).
[0082] Note that the control device 30 acquires the position
information of the projecting member 20 successively changing
according to the downward movement of the projecting member 20.
[0083] By the downward movement of the projecting member 20, the
linkage mechanism 60 operates, whereby the opening/closing plate 3
rotates about the support shaft 4 and the projection opening 2h is
opened (step S5). By this, it becomes possible to project an image
from the projection lens 38 through the projection opening 2h.
[0084] The control device 30 moves the projecting member 20 until
the position information of the projecting member 20 detected by
the position detector 70 and the position of the projecting member
20 stored in the memory 32 match (step S6).
[0085] When the projecting member 20 projected from the bottom
surface 2d of the case 2 at the previous shut off of the power, the
projecting member 20 projects again from the bottom surface 2d of
the case 2, whereby the case 2 is inclined so as to give an
elevation angle .theta. the same as that of the previous time.
[0086] After the movement of the projecting member 20 stops, when a
video signal is applied from the input terminal 45 to the LCD panel
37 via the drive circuit 34, the image modulated and generated by
the LCD panel 37 is projected to the screen SC (step S7).
[0087] In this state, in order to adjust the height of the image
projected on the screen SC, the control device 30 decides if the
elevation instruction buttons 5a and 5b for instructing upward
movement or downward movement of the projecting member 20 (or the
rising or lowering of the elevation angle) were operated (step S8).
When the operation buttons 5a and 5b were operated, and the
instruction signals 5as and 5bs are input to the control device 30.
The control device 30 elevates the projecting member 20 based on
these instruction signals 5as and 5bs to adjust of the elevation
amount of the projecting member 20 (step S9). By this, the height
of the image on the screen SC is adjusted.
[0088] When the power switch 6 is operated and the off signal 6s is
input from the power switch 6, the control device 30 stops the lamp
power supply 35 (step S11).
[0089] Further, the control device 30 acquires the present position
of the projecting member 20 from the position detector 70 and newly
stores this position information in the memory 32 (step S12).
[0090] After storing the position of the projecting member 20 in
the memory 32, the control device 30 reads the information of the
storage position of the projecting member 20 stored in the memory
32 and outputs the instruction 30s1 for driving the electric motor
51 and the instruction 30s2 for defining the rotation direction to
the amplifier circuit 33 based on the read position
information.
[0091] By this, the projecting member 20 moves upward toward the
predetermined storage position (step S13).
[0092] In the middle of movement of the projecting member 20 toward
the predetermined storage position, the arm 20A of the projecting
member 20 abuts against the abutment 61a of the link member 61
again, whereby the linkage mechanism 60 operates. By this, the
opening/closing plate 3 rotates about the support shaft 4 in the
direction closing the projection opening 2h, whereby the projection
opening 2h is closed again (step S14).
[0093] When the projecting member 20 reaches the predetermined
storage position, the storage of the projecting member 20 is
completed (step S15).
[0094] As described above, according to the present embodiment,
when electric power is supplied to the image projection apparatus
1, the projecting member 20 for adjusting the elevation angle
.theta. of the image projection apparatus 1 is automatically
returned to the position where the power was shut off the previous
time and, at the same time, the opening/closing plate 3 covering
the front surface of the projection lens 38 is opened by utilizing
the movement of the projecting member 20. By this, preparatory work
for projecting an image by the image projection apparatus 1 is
automatically carried out, and the time and procedures required for
the preparation work whenever the image projection apparatus 1 is
used are much reduced.
[0095] Further, when shutting off the power to the image projection
apparatus 1, by automatically storing the projecting member 20 at
the predetermined storage position in the case 2 and, at the same
time, automatically closing the opening/closing plate 3, the time
and procedures required for the storage work are again greatly
reduced.
[0096] Note that, the present invention is not limited to the above
embodiment.
[0097] The above embodiment was configured to open or close the
projection opening 2h by rotating the opening/closing plate 3 about
the support shaft 4, but it is also possible to employ a
configuration wherein the opening/closing plate is slidably
provided to open and close the projection opening 2h.
[0098] Further, the case where power is transmitted from the
electric motor 51 to the projecting member 20 by using a
transmission mechanism comprising the worm gear 52, the gear 53,
and the screw shaft 54 was exemplified, but it is also possible not
to use the worm gear 52, but use a gear train comprising spur
gears.
[0099] Further, in the above embodiment, the elevation instruction
buttons 5a and 5b were arranged on the top surface of the case 2,
but it is also possible to employ a constitution wherein they are
arranged on the back surface opposite to the front surface 2a of
the case 2. This is because, the back surface of the case 2 is also
near the shaft S, and the position almost never fluctuates due to
inclination. In this case, by using a so-called seesaw switch able
to change in posture in accordance with the inclination of the case
2 as the elevation instruction buttons 5a and 5b, the operability
is further improved.
[0100] Further, in the above embodiment, when the off signal 6s is
input from the power switch 6, the control device 30 operated to
acquire the present position of the projecting member 20 from the
position detector 70 and newly store this position information in
the memory 32, but it is also possible to employ a constitution,
for example, storing the position information of the projecting
member 20 when operating the elevation instruction buttons 5a and
5b to incline the image projection apparatus 1 to the desired
elevation angle in the memory 32 and storing the present position
information of the projecting member 20 in the memory 32 before the
off signal 6s is input from the power switch 6. Alternatively, it
is also possible to store the information setting the elevation
angle desired by the user or the position of the projecting member
20 in the memory 32.
[0101] Note that a formula or table indicating the relationship
between the elevation angle and the height position of the
projecting member 20 can be stored in the memory of the control
device 30. Accordingly, it is also possible to set it as the
elevation angle or set it as the height position (elevation
position) of the projecting member 20.
[0102] At the time of restart of the image projection apparatus 1,
the control device 30 controls the drive of the adjuster mechanism
50 so as to obtain the elevation angle or the elevation position of
the projecting member 20 held in the memory 32 with reference to
the detected value of the position detector 70.
[0103] The above description was made of the example wherein the
adjuster mechanism 50 and the linkage mechanism 60 for operating
the opening/closing plate for opening or closing the projection
opening were linked as a preferred embodiment of the present
invention, but it is also possible to operate only the adjuster
mechanism 50.
[0104] Note that while an example using an LCD unit as the means
for projecting the image to the projection lens was explained
above, the image projection apparatus of the present invention is
not limited to the case where the LCD unit is used so far as it is
an apparatus of providing an image to the projection lens.
[0105] Further, in the image projection apparatus of the present
invention, as mentioned above, the position where the projecting
member 20 serving as the elevation member was completely contained
in the case 2 was determined as the first position, that is, the
storage position was determined as the first position, but the
first position of the present invention may also be a position
where the projecting member 20 is not contained in the case 2 in
its entirety, but is partially exposed to the outside of the case 2
so long as the lower end of the projecting member 20 does not abut
against the base BS corresponding to the setting surface of the
present invention, and does not generate elevation angle. The
second position of the present invention means the position where
the lower end of the projecting member 20 serving as the elevation
member abuts against the base BS and starts the generation of the
elevation angle, while the third position of the present invention
means the position where the projecting member 20 projects so that
the elevation angle becomes further larger from the second
position.
[0106] According to the present invention, an image projection
apparatus which can easily adjust the position of an image for
projecting the image onto the screen and also can easily return the
elevation member of the present invention (projecting member of the
adjuster mechanism) to the first position (return position) is
provided.
INDUSTRIAL APPLICABILITY
[0107] The present invention can be applied to for example various
image projection apparatuses.
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