JP2005172959A - Projection type video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projection type video display device capable of preventing dust from getting into a housing even in the case of securing large void between a projection lens and the aperture of a front cover. <P>SOLUTION: In the video display device, a dust-proof plate 8 is externally fit to the body part of the projection lens 6, and is constituted of a 1st member 81 and a 2nd member 82. The member 81 moves to follow the up-and-down movement and the right-and-left movement of the lens 6, while the member 82 does not move with the up-and-down movement of the lens 6 but moves to follow only the right-and-left movement thereof. A flexible projecting part 81a respectively projecting to either side and the other side in the moving direction is formed on the member 81. The video display device is constituted so that the flexible projecting part 81a on either side is curved and guided to the inner side of the device by the movement of the lens 6, and also the flexible projecting part 81a on the other side is pulled out from the inner side of the device, and a circular insertion hole (projection lens inserting hole) of the front cover is always set in a partitioned state with respect to the inner part of the housing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a projection image display apparatus provided with a lens shift mechanism.

  FIG. 7 is a diagram illustrating an optical system of a three-plate color liquid crystal projector. The light emitting part of the light source 101 is composed of an ultra-high pressure mercury lamp, a metal halide lamp, a xenon lamp or the like, and the irradiated light is emitted as parallel light by a parabolic reflector and guided to the integrator lens 102.

  The integrator lens 102 is composed of a pair of lens groups, and each pair of lenses guides light emitted from the light source 101 to the entire surface of the liquid crystal light valves 111, 112, 113. The light that has passed through the integrator lens 102 is guided to the first dichroic mirror 103.

  The first dichroic mirror 103 transmits light in the red wavelength band and reflects light in the cyan (green + blue) wavelength band. The light in the red wavelength band that has passed through the first dichroic mirror 103 is reflected by the total reflection mirror 104 to change the optical path. The red light reflected by the total reflection mirror 104 is light-modulated by passing through the condenser lens 108 and the transmissive liquid crystal light valve 111 for red light. On the other hand, the light in the cyan wavelength band reflected by the first dichroic mirror 103 is guided to the second dichroic mirror 105.

  The second dichroic mirror 105 transmits light in the blue wavelength band and reflects light in the green wavelength band. The light in the green wavelength band reflected by the second dichroic mirror 105 is guided through the condenser lens 109 to the transmissive liquid crystal light valve 112 for green light, and is modulated by being transmitted therethrough. Further, the light in the blue wavelength band that has passed through the second dichroic mirror 105 is guided to the blue-light transmissive liquid crystal light valve 113 through the total reflection mirrors 106 and 107 and the condenser lens 110 and is transmitted therethrough. Is modulated by light.

  Each of the liquid crystal light valves 111, 112, and 113 includes an incident-side polarizing plate, a panel portion in which liquid crystal is sealed between a pair of glass substrates (pixel electrodes and alignment films are formed), an outgoing-side polarizing plate, Comprising. The modulated light (each color video light) modulated by passing through the liquid crystal light valves 111, 112, 113 is synthesized by the dichroic prism 114 to become color video light. The color image light is enlarged and projected by the projection lens unit 115 and projected and displayed on the screen.

In such a liquid crystal projector, there is known a projector provided with a lens shift mechanism that moves the projected image up and down without changing the main body and reduces the trapezoidal shape of the projected image (see Patent Document 1).
JP-A-9-138377

  In the lens shift mechanism, it is possible to secure a relatively large lens shift width in the vertical direction and the horizontal direction. For this purpose, the projection lens and the opening of the front cover in the liquid crystal projector correspond to the lens shift width. A large gap must be secured between the two. However, the large gap in the opening in the front cover not only deteriorates the appearance, but also causes inconvenience that dust easily enters the projector housing.

  In view of the above circumstances, the present invention provides a projection display apparatus that can prevent dust from entering the housing even when a large gap is secured between the projection lens and the opening of the front cover. With the goal.

  In order to solve the above problems, a projection display apparatus according to the present invention is a projection display apparatus provided with a lens shift mechanism that shifts a projection lens that performs image projection in a direction orthogonal to the optical axis thereof. A dust-proof plate is externally fitted to the body of the projection lens, and the dust-proof plate is formed with flexible convex portions projecting on one side and the other side in the moving direction thereof. By the movement, the flexible convex portion on one side is curved and guided to the back side of the apparatus, and the flexible convex portion on the other side is pulled out from the back side of the apparatus.

  With the above configuration, since the dustproof plate is provided on the projection lens, it is possible to prevent dust from entering the housing even when a large gap is secured between the projection lens and the opening. Here, it is conceivable to use a bellows plate or a sponge-like member in place of the flexible convex portion. However, as the apparatus becomes higher, the repulsive force increases as it shrinks, and the projection lens becomes difficult to move. On the other hand, in the above configuration, since the flexible convex portion is guided to the back side of the apparatus, such a drawback is eliminated, and the apparatus can be thinned and the projection lens can be moved smoothly.

  The dust-proof plate has a first member in which a hole having substantially the same diameter as the body of the projection lens and the flexible convex portion are formed, a hole through which the projection lens is inserted, and the first member. It is good to comprise the 2nd member slidably supported in the moving direction. The dust-proof plate follows the entire first member and the second member with respect to the horizontal movement of the projection lens, and only the first member slides on the second member with respect to the vertical movement. It is good to move and follow.

  In these configurations, it is preferable that a restricting member for restricting the dustproof plate from moving in the depth direction is provided.

  According to the present invention, even when a large gap is secured between the projection lens and the opening of the front cover, dust can be prevented from entering the housing, and further, the apparatus can be made thinner and the projection lens can be moved. There is an effect that smoothness can be achieved.

  Hereinafter, a projection display apparatus according to an embodiment of the present invention will be described with reference to FIGS. Note that the projection display apparatus of the embodiment shown below is a liquid crystal projector using three transmissive liquid crystal display panels, and the image light generation optical system is the liquid crystal shown in FIG. 7 used in the description of the conventional example. Since it is the same as the projector, the description of the optical system will be omitted, and the lens shift mechanism and the dustproof structure will be mainly described.

[Fixed base 1]
As shown in FIGS. 5 and 6, a vertical drive mechanism 2 and a horizontal drive mechanism 3 are provided on the fixed base 1. The fixed base 1 is fixed to the front side of a body chassis (not shown), and the dial 24 in the vertical drive mechanism 2 and the dial 34 in the horizontal drive mechanism 3 are exposed from the hole of the front cover 7 (see FIG. 1) of the liquid crystal projector. To do. In addition, a projection lens 6 (see FIG. 1) is attached to the vertical movable base 5, and the projection lens 6 projects from a circular hole 7a of the front cover. Horizontal elongate holes 1a are formed in the upper two places and the lower one place of the fixed base 1. The length of the horizontal elongated hole 1a corresponds to the movable range of the horizontal movable base 4 described later. In addition, the fixed base 1 is formed with an opening 1b for passing the projection video light. The opening 1b is not a quadrilateral shape, but is formed in an octagonal shape having a 45 ° oblique side 1c without forming corners at the four corners.

[Vertical drive mechanism 2]
The drive mechanism chassis 21 is provided with a rotating body 22 that rotates about a horizontal axis. A dial 24 is fitted to the rotating body 22, and when the dial 24 is rotated in a rotatable state of the rotating body 22, the rotating body 22 is rotated by frictional force, but the dial 24 is rotated in a non-rotatable state of the rotating body 22. However, the rotating body 22 does not rotate, and the dial 24 only slips. A bevel gear 22a is fixed to the right end side of the rotating body 22 in the figure, and the bevel gear 22a meshes with the bevel gear 23a. The bevel gear 23 a is formed on the front end side of the first driving force transmission body 23. The first driving force transmission body 23 is provided such that the axial direction is set in the front-rear direction and the shaft can be rotated around the axis. Further, a worm portion 23 b is formed on the back end side of the first driving force transmission body 23. The worm portion 23b meshes with a worm gear portion 25a formed on the right end side of the second driving force transmission body 25 in the drawing. The second driving force transmission body 25 has an axial direction set to a horizontal direction, and a gear portion 25b is formed on the left end side in the drawing. The gear portion 25b has a wide width corresponding to the horizontal movement range of the vertical movable base 5 (that is, the horizontal movable range of the horizontal movable base 4).

[Horizontal drive mechanism 3]
The drive mechanism chassis 31 is provided with a rotating body (not shown in order to be hidden in FIG. 3) that rotates about a vertical axis. A dial 34 is fitted to the rotating body, and when the dial 34 is rotated in a rotatable state of the rotating body, the rotating body rotates by frictional force, but even if the dial 34 is rotated in a non-rotatable state of the rotating body, the rotating body is rotated. Does not rotate, and only the dial 34 slips. A worm portion 32 is formed on the lower end side of the rotating body, and the worm portion 32 meshes with the worm gear portion 33a. The worm gear portion 33 a is formed on the front end side of the driving force transmission body 33. The driving force transmission body 33 is provided such that the axial direction is set in the front-rear direction and the shaft can be rotated around the axis. A gear portion 33 b is formed on the back end side of the driving force transmission body 33.

[Horizontal movable base 4]
The horizontal movable base 4 is indicated by a thick solid line in FIG. Projecting portions 4a are formed at two upper and one lower side of the back surface (back side surface) of the horizontal movable base 4 in correspondence with the positions where the three horizontal elongated holes 1a of the fixed base 1 are formed. The protruding portion 4 a protrudes from the back surface side of the fixed base 1 through the horizontal elongated hole 1 a. And the washer which has a larger diameter than the width | variety of the horizontal long hole 1a is externally fitted by the protrusion part 4a, and also the spring holding process is performed after the coil spring is externally fitted by the protrusion part 4a. As a result, the horizontal movable base 4 moves in the horizontal direction while being guided by the horizontal elongated hole 1a while being pressed against the fixed base 1 by the bias of the coil spring. On the right end side of the horizontal movable base 4 in the figure, a horizontal gear portion 4b is formed. The gear portion 33b of the driving force transmission body 33 is engaged with the horizontal gear portion 4b, and the horizontal movable base 4 moves horizontally by obtaining the rotational force of the gear 33b. Further, projection video light passage openings 4c are formed in the central portion of the horizontal movable base 4, and entrance portions 4d communicating with the openings 4c are formed at the four corners of the passage openings 4c. . The insertion portion 4d is formed to avoid interference with a boss portion (a screw hole for mounting the projection lens 6 is formed) formed in the vertical movable base 5. Further, vertical elongated holes 4e are formed at two positions on the right side of the passage opening 4c in the horizontal movable base 4, and vertical elongated holes 4e are formed at one position on the left side.

[Vertical movable base 5]
The vertical movable base 5 is mounted on the horizontal movable base 4. On the back surface of the vertical movable base 5, a boss portion with a screw hole is formed corresponding to the position where the vertical elongated hole 4e is formed. Then, a leaf spring body 51 wider than the vertical elongated hole 4e is disposed on the back side of the horizontal movable base 4, and the leaf spring body 51 is attached to the boss portion by a screw. Accordingly, the vertical movable base 5 moves in the vertical direction while the boss portion is guided by the vertical elongated hole 4e while being pressed against the horizontal movable base 4 by the urging force of the leaf spring body 51. At the lower right position of the vertical movable base 5, a rack portion 52 is formed in the vertical direction where the gear portion 25 b of the second driving force transmission body 25 is engaged. The vertical movable base 5 is driven in the vertical direction by receiving the driving force of the gear portion 25b in the rack portion 52. In addition, a circular opening 53 for passing the projected image light is formed at the center of the vertical movable base 5. Four movement restricting convex portions 54 are formed on the back surface side of the vertical movable base 5. The movement restricting convex portion 54 is on a line perpendicular to the central portion of the 45 ° oblique side portion 1c of the fixed base 1 in a state where the vertical movable base 5 and the horizontal movable base 4 are both located in the center (projection lens central arrangement state). It is formed at a position in the vicinity of the circular opening 53. Further, the amount of protrusion of the movement restricting convex portion 54 is set to a degree slightly exceeding the back side of the fixed base 1.

  When the vertical movable base 5 and the horizontal movable base 4 are both located at the center (projection lens central arrangement state), when the finger is applied to the dial 24 and applied with a force upward from below, the vertical movable base 5 is moved. When driven, the projection lens 6 moves upward. Similarly, when a finger is applied to the dial 24 and a force is applied from above to rotate it, the horizontal movable base 4 is driven and the projection lens 6 moves downward. Further, when the vertical movable base 5 and the horizontal movable base 4 are both located in the center (projection lens central arrangement state), when the finger is applied to the dial 34 and applied with a force from the left to the right, the horizontal movable base is rotated. 4 is driven and the projection lens 6 moves to the right. Similarly, when a finger is put on the dial 34 and a force is applied from the right to the left to rotate it, the horizontal movable base 4 is driven and the projection lens 6 moves to the left.

[Dust-proof structure]
As shown in FIG. 1, a dustproof plate 8 is fitted on the body of the projection lens 6. As shown in FIG. 2, the dustproof plate 8 includes a first member 81 and a second member 82. The first member 81 moves following the vertical and horizontal movements of the projection lens 6, while the second member 82 does not move when the projection lens 6 moves up and down, and moves only following the horizontal movement.

  The first member 81 includes flexible convex portions 81a and 81a and a circular central body portion 81b. The flexible convex portion 81a has a length corresponding to the vertically movable range of the projection lens 6, and is formed to project from the upper side and the lower side of the central body portion 81b. The flexible convex portion 81 a is passed through a sliding gap portion 82 d formed in the second member 82. The horizontal width of the central body 81b of the first member 81 is formed larger than the circular insertion hole 7a for inserting the projection lens 6 formed in the front cover 7, and the projection lens is located at the center of the central body 81b. A hole portion 81c having a diameter approximately the same as the diameter of the body portion 6 is formed. The body portion of the projection lens 6 is inserted through the hole 81c. Furthermore, a slide wall 81d is formed on the back side of the central body 81b.

  The second member 82 is made of a plastic that is not easily deformed, has arcuate protrusions 82c on both sides of the rectangular frame 82a, and slide walls 82b that engage both sides of the slide wall 81d. Is made. The arcuate protrusion 82c is somewhat larger than the circular insertion hole 7a. On the upper end and the lower end of the second member 82, guide gap portions 82d for guiding the flexible convex portion 81a to the back side of the apparatus are formed. The vertical length of the rectangular frame portion 82a has a length corresponding to the vertically movable range of the projection lens 6, and the horizontal width of the rectangular frame portion 82a is equal to the diameter of the body portion of the projection lens 6 by the projection 82e. The width is about the same.

  FIG. 3 is a view showing the projection lens 6 when it is moved upward, when it is centered, and when it is moved downward. FIG. 3A is a front view showing a state in which a front cover is present, and FIG. Is a front view with the front cover removed, and FIG. As can be seen from these drawings, when the projection lens 6 moves up and down, the second member 82 does not move, and only the first member 81 guided in the vertical direction by the slide wall 82b of the second member 82 is the projection lens. It moves following 6 movement. In this movement, one flexible convex portion 81a is curved and guided to the back of the apparatus, and the other flexible convex portion 81a is pulled out from the back of the apparatus. The insertion hole 7a is always partitioned from the inside of the housing. Here, it is conceivable to apply a bellows plate or a sponge-like member in place of the flexible convex portion 81a. However, even if the bellows plate or the sponge-like member shrinks, some thickness remains. The device becomes higher by the amount, and the repulsive force increases as the device shrinks, and the projection lens 6 becomes difficult to move. On the other hand, since the flexible convex portion 81a is guided to the back side of the apparatus in the above configuration, such a drawback is eliminated, and the apparatus can be thinned and the projection lens can be moved smoothly.

  FIG. 4 is a view showing the projection lens 6 when it moves to the right, when it moves to the center, and when it moves to the left. FIG. 4 (a) is a front view of the state where the front cover is present, and FIG. Is a front view with the front cover removed, and FIG. As can be seen from these drawings, when the projection lens 6 moves left and right, the first member 81 and the second member 82 integrally move following the movement of the projection lens 6, and the circular insertion hole of the front cover 7. 7a is always partitioned from the inside of the housing.

  A regulating member 11 that regulates the movement of the dustproof plate 8 in the depth direction is provided on the back side of the dustproof plate 8 (see FIG. 1). The gap between the regulating surface of the regulating member 11 and the front cover 7 is slightly wider than the thickness of the dustproof plate 8. The regulating member 11 is screwed to the side wall of the drive mechanism chassis 31 described above.

  As described above, in such a liquid crystal projector, since the dust-proof plate 8 is provided on the projection lens 6, even when a large gap is secured between the projection lens 6 and the circular insertion hole 7 a of the front cover 7, dust is not contained. Can prevent entry into the body. Since the dust-proof plate 8 is only fitted on the body of the projection lens 6, the assembling work is very easy. In addition, the apparatus can be made thinner and the movement of the projection lens can be made smoother. In addition, since the restricting member 11 that restricts the movement of the dustproof plate 8 in the depth direction is provided, even if the projection lens 6 has a structure that can move a little in the optical axis direction, the dustproof plate 8 moves in the depth direction following that. It is possible to prevent a large gap from being formed between the front cover 7 and the front cover 7.

  In the above-described embodiment, an image generation optical system using three transmissive liquid crystal display panels is shown. However, another image generation optical system may be provided. Further, by arranging the above-described lens shift mechanism by being rotated by 90 °, the vertical movable base 5 can be moved horizontally and the horizontal movable base 4 can be moved vertically.

It is the perspective view which showed the dust-proof structure part in the liquid crystal projector of this invention. It is the disassembled perspective view which showed the dustproof board in the said dustproof structure part. FIG. 4A is a diagram illustrating the time when the projection lens is moved upward, the center time, and the time when the projection lens is moved downward. FIG. 5A is a front view showing a state in which a front cover is present, and FIG. It is the front view of the state removed, and the figure (c) is a longitudinal section. FIG. 4A is a diagram illustrating a time when the projection lens is moved to the right, a center time, and a time when the projection lens is moved to the left. FIG. 5A is a front view showing a state in which a front cover is present, and FIG. It is the front view of the state which removed, The figure (c) is a cross-sectional view. It is the perspective view which illustrated the lens shift mechanism. FIGS. 2A and 2B are diagrams illustrating the lens shift mechanism, in which FIG. 1A is a plan view in a state where a vertical movement base is omitted, and FIG. It is explanatory drawing which showed the optical system of the general liquid crystal projector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed base 2 Vertical drive mechanism part 3 Horizontal drive mechanism part 4 Horizontal movable base 5 Vertical movable base 6 Projection lens 7 Front cover 8 Dust-proof board 81 1st member 82 2nd member 11 Control member

Claims (4)

In a projection display apparatus having a lens shift mechanism that shifts a projection lens that performs image projection in a direction orthogonal to the optical axis, a dust-proof plate is externally fitted to the body of the projection lens, and the dust-proof plate Is formed with a flexible convex portion that protrudes on one side and the other side in the moving direction, and the flexible convex portion on one side is curved by the movement of the projection lens and moves toward the back of the apparatus. And a flexible convex part on the other side is pulled out from the back of the apparatus. The projection type image display device according to claim 1, wherein the dustproof plate includes a first member in which a hole portion having substantially the same diameter as a body portion of the projection lens and the flexible convex portion are formed, and the projection lens. And a second member for slidingly supporting the first member in the moving direction thereof. 3. The projection display apparatus according to claim 2, wherein the dustproof plate follows the whole of the first member and the second member with respect to the movement of the projection lens in the horizontal direction and the movement of the projection lens in the vertical direction. Only the first member slides on the second member to follow the projection-type image display device. 4. The projection display apparatus according to claim 1, further comprising a restricting member for restricting the dustproof plate from moving in the depth direction. .

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