JP4033890B2 - Projection display device - Google Patents

Description

  The present invention relates to a projection display apparatus having a lens shift mechanism.

  FIG. 8 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.

  FIG. 9 is a perspective view showing a lens shift mechanism for moving the projection lens unit 115 in the vertical direction. With this lens shift mechanism, the projected image can be moved up and down without changing the liquid crystal projector main body, and the projection image can be reduced from being trapezoidal.

Sliding bearings 121a are provided at the four corners of the moving base 121 to which the projection lens unit 115 is fixed. Is done. A plate member 121 b is fixed to the side portion of the moving base 121. A screw hole is formed in the plate member 121b, and the male screw portion 123a of the elevating shaft 123 is screwed into the screw hole. The screw shaft 123 is only allowed to rotate, and the upper and lower portions are supported by bearings 124 so as not to move up and down. The bearing 124 and the guide shaft 122 are fixed to a fixed base 129. A worm gear 125 is fixed to the lower end portion of the screw shaft 123, and a worm screw 126 fixed to the rotating shaft of the motor 127 is screwed to the worm gear 125. As the rotation shaft of the motor 127 rotates, the screw shaft 123 rotates and the plate member 121b moves up and down, and the moving base 121 connected to the plate member 121b moves up and down.

  In the lens shift mechanism, in order to smoothly move the moving base 121 up and down, the guide shaft 122 is made of a metal such as stainless steel and is smoothly ground, and the bearing 121a is polyacetal (POM) or the like. Resin and oilless bearings are used. However, in order to reduce the shaft runout when the moving base 121 moves up and down, it is necessary to reduce the gap between the guide shaft 122 and the bearing 121a, and the dimension from the reference surface of the moving base 121 to the four bearings 121a. High accuracy is required for the parallelism, and the dimension and parallelism from the reference surface of the fixed base 129 to the guide shaft 122. If these tolerances are reduced, they move due to component variations and cumulative errors. The base 121 may not be lifted and lowered smoothly.

  If the conventional lens shift mechanism is used to move the projection lens unit 115 up and down and left and right, the components such as the moving base 121, the guide shaft 122, the sliding bearing 121a, and the screw shaft 123 are moved up and down. Two sets for shifting are required, which causes problems such as an increase in the number of parts, an increase in weight, and a decrease in assembly workability.

  In view of the above circumstances, the present invention is provided with a lens shift mechanism and a lens shift mechanism that are less likely to be complicated in structure even when the projection lens unit is shifted up, down, left, and right, and that can be easily operated. Another object of the present invention is to provide a projection display apparatus.

  Means for solving the above-mentioned problems is a projection-type image display device having a lens shift mechanism for shifting a projection lens unit for projecting an image in a direction orthogonal to the optical axis thereof, wherein the lens shift mechanism is a chassis. A substantially rectangular second fixed side plate material fixed to the first fixed side plate material, a substantially rectangular plate-shaped first fixed side plate material arranged opposite to the second fixed side plate material, a first fixed side plate material and a second fixed side A substantially rectangular plate-shaped lens mounting member slidably disposed between the plate material, a projection lens unit fixed to the lens mounting member through an insertion hole formed in the first fixed-side plate material, and a lens mounting A pressing means for pressing the member against the first fixed side plate or the second fixed side plate, a rotation member having a rotation center parallel to the optical axis, and a position eccentric from the rotation center of the rotation member. Provided on the projection and lens mounting member Is characterized in that it comprises an engaging portion which engages with the protrusion, and a driving mechanism for rotationally driving the rotating member.

  According to the present invention, since the guide shaft and the sliding bearing in the lens shift mechanism having the conventional configuration are unnecessary, the structure is hardly complicated even when the projection lens unit is shifted up and down and left and right. In addition, if the projection lens unit is to be shifted to the right, it is only necessary to apply an operating force in the right direction to the dial. If the projection lens unit is to be shifted in the upward direction, an upward operating force is applied to the dial. In other words, the user can perform the lens shift operation without a sense of incongruity.

  A lens shift mechanism and a projection display apparatus according to the present invention will be described below with reference to FIGS. The projection display apparatus of the embodiment shown below is a liquid crystal projector using three transmissive liquid crystal display panels, and the liquid crystal projector of FIG. 8 used in the description of the conventional example is used for the image generation optical system. Therefore, the description of the optical system is omitted, and the lens shift mechanism will be mainly described.

  FIG. 1 is a perspective view showing a lens shift mechanism of this embodiment. This lens shift mechanism includes a first fixed side plate member 1, a second fixed side plate member 2, a lens holder 3, drive mechanism portions 4A and 4B, and guide members 5A and 5B. The second fixed side plate 2 is fixed to the chassis in the liquid crystal projector. A lens unit (not shown) is fixed to the lens holder 3.

  2A and 2B are views showing the first fixed side plate 1, wherein FIG. 2A is a plan view thereof, and FIG. 2B is a side view thereof. The central circular through hole is a lens unit insertion hole 1a (not shown), and the right and lower rectangular through holes 1b and 1c communicating with the insertion hole 1a are for the guide members 5A and 5B. This is a mounting hole.

  In the standing portion 1d, two round holes 1e and 1e are formed in the direction perpendicular to the paper surface of FIG. 1A (parallel to the optical axis direction of the lens unit). A moving member 41 is rotatably inserted. Moreover, the hole 1f is formed in the lower surface of the 1st fixed side board | plate material 1, and the sliding contact body 11 is inserted in each hole 1f. The sliding contact body 11 is formed using, for example, polyacetal (POM), polyamide (PA), polytetrafluoroethylene (PTFE), or the like.

  A coil spring 12 is provided in each hole 1 f, and the sliding contact body 11 presses the lens holder 3 toward the second fixed side plate member 2 by the coil spring 12. The pressing force at this time is set so that the lens holder 3 (lens unit) can be held and moved. That is, when a force for movement is applied to the lens holder 3, the lens holder 3 moves, and when the force is stopped, the pressing force is set so that the position of the lens holder 3 is held at that position.

  FIGS. 3A and 3B are views showing the second fixed side plate 2, in which FIG. 3A is a plan view and FIG. 3B is a side view thereof. Upright portions 2 a are formed at two locations on the edge side of the second fixed side plate member 2. The first fixed side plate material 1 and the second fixed side plate material 2 are fixed by placing the first fixed side plate material 1 on the upright portion 2a and screwing, and a space between them. The lens holder 3 can be positioned in this space.

  Further, the second fixed side plate member 2 is formed with sliding contact projections 2b, and the lens holder 3 is placed on the sliding contact projections 2b.

  4A and 4B are views showing the lens holder 3, in which FIG. 4A is a plan view and FIG. 4B is a side view thereof. The central through hole 3a is a light introducing hole for a lens unit (not shown). In FIG. 6A, the groove 3b that is long in the left-right direction is a hole in which the protrusion 41a (see FIGS. 5 and 6) of the rotating member 41 that moves the lens holder 3 in the up-down direction in FIG. In the drawing, the concave groove 3c that is long in the vertical direction is a hole in which the protrusion 41a of the rotating member 41 that moves the lens holder 3 in the horizontal direction in the drawing is engaged.

  Note that a friction reducing member is preferably provided in the concave groove 3b and the concave groove 3c. The cut portions 3d and 3d and the cut portions 3e and 3e are fitted with L-shaped metal fittings (not shown) to form concave grooves, and the guide protrusions 51 of the guide members 5A and 5B are engaged with the cut portions 3d and 3d. ing.

  FIG. 5 is a perspective view showing an engagement state between the protrusion 41a of the rotating member 41 and the groove 3c in the driving mechanism 4A, and FIG. 6 is a side view of the rotating member 41. As shown in FIG. A projecting portion 41b projecting sideways is formed at the lower portion of the rotating member 41, and the projecting portion 41a is formed on the lower surface of the distal end of the projecting portion 41b.

  That is, the protrusion 41 a is eccentric with respect to the rotation center of the rotation member 41. In addition, a protruding portion 41 c protruding sideways is formed on the upper portion of the rotating member 41. The protruding direction of the protruding portion 41c is shifted by 90 ° with respect to the protruding direction of the protruding portion 41b. And the protrusion part 41d is formed in the front-end | tip upper surface of the said protrusion part 41c. That is, the protrusion 41 d is also eccentric with respect to the rotation center of the rotation member 41. The protrusion 41 d is engaged with a hole formed in the lower surface of the moving member 42.

  The moving member 42 is screwed into a screw portion 44 fixed to the dial 43. The dial 43 and the screw part 44 are only allowed to rotate and are restricted from moving in the axial direction. In FIG. 5, when the dial 43 is operated in the A direction, the moving member 42 moves in the B direction. When the moving member 42 moves in the B direction, the rotating member 41 rotates in the C direction. As the rotating member 41 rotates in the C direction, the protrusion 41a pushes the lens holder 3 in the D direction.

  That is, when the dial 43 is turned in the A direction, the lens holder 3 (lens unit) moves in the D direction, which is the same direction as the A direction. As shown in FIG. 7A, the drive mechanism unit 4B includes the same mechanism as the drive mechanism unit 4A, but the positional relationship is shifted by 90 ° with respect to the drive mechanism unit 4A. Yes.

  As shown in FIG. 7B, the guide member 5A has guide projections 51 at the lower ends of both ends in the longitudinal direction. Further, the guide member 5A has shafts 52 at both upper ends in the longitudinal direction, and the axial direction is made to coincide with the shift direction (vertical direction) of the lens holder 3. The guide member 5B has guide protrusions 51 at both lower ends in the longitudinal direction and shafts 52 at both upper ends in the longitudinal direction, and the axial direction coincides with the shift direction (left-right direction) of the lens holder 3. I am letting.

  The guide member 5A ensures linearity of movement when the lens holder 3 is moved by operating the dial 43 of the drive mechanism section 4A, and when the lens holder 3 is moved by operating the dial 43 of the drive mechanism section 4B. In addition, by swinging about the shaft 52, the lens holder 3 is followed and the engaged state with the lens holder 3 is maintained.

  Further, the guide member 5B ensures the linearity of movement when the dial 43 of the drive mechanism unit 4B is operated to move the lens holder 3, and the lens holder 3 is moved by operating the dial 43 of the drive mechanism unit 4A. At this time, by swinging about the shaft 52, the lens holder 3 is followed to maintain the engaged state with the lens holder 3.

  In the embodiment described above, the coil spring 12 is used as means for pressing the lens holder 3 against the second fixed-side plate member 2, but other springs such as a plate spring may be used instead of the coil spring 12. Alternatively, not only a spring but also an elastic body such as rubber may be used. In addition, the lens holder 3 is not limited to being pressed against the second fixed side plate member 2, but the lens holder 3 may be pressed against the first fixed side plate member 1.

  It is also possible to employ a worm gear mechanism configuration by fixing a gear to the upper end portion of the rotating member 41 instead of the moving member 42. In addition, the image generation optical system using three transmissive liquid crystal display panels is shown. However, the image generation optical system is not limited to such an image generation optical system, and may be applied to the case of using another image generation optical system. it can.

It is the perspective view which showed the lens shift mechanism of this invention. It is the figure which showed the 1st fixed side board | plate material, Comprising: The figure (a) is the top view, The figure (b) is the side view. It is the figure which showed the 2nd stationary side board | plate material, Comprising: The figure (a) is the top view, The figure (b) is the side view. It is the figure which showed the lens holder, Comprising: The figure (a) is the top view, The figure (b) is the side view. It is the perspective view which showed the engagement state of the projection part of the rotation member in a drive mechanism part, and a ditch | groove. It is a side view of a rotation member. FIG. 4A is a plan view of the lens shift mechanism, and FIG. 4B is a side view thereof. It is explanatory drawing which showed the optical system of the general liquid crystal projector. It is the perspective view which showed the conventional lens shift mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st fixed side board | plate material 2 2nd fixed side board | plate material 3 Lens holder 4A Drive mechanism part 4B Drive mechanism part 5A Guide member 5B Guide member 41 Rotating member 42 Moving member 43 Dial 44 Screw part 115 Projection lens unit

Claims (1)

In the projection display apparatus including a lens shift mechanism that shifts a projection lens unit that performs image projection in a direction orthogonal to the optical axis, the lens shift mechanism is a second substantially rectangular second shape fixed to the chassis. A fixed-side plate, a substantially rectangular plate-like first fixed-side plate arranged opposite to the second fixed-side plate, and a slidable arrangement between the first fixed-side plate and the second fixed-side plate A substantially rectangular plate-shaped lens mounting member, a projection lens unit fixed to the lens mounting member through an insertion hole formed in the first fixed-side plate material, and the lens mounting member as the first fixed-side plate material or the second A pressing means for pressing the fixed side plate member, a rotating member having a rotation center parallel to the optical axis, a protrusion provided at a position eccentric from the rotation center of the rotation member, and a lens mounting member The engaging portion that engages with the protruding portion , The projection display device, characterized in that a drive mechanism for rotationally driving the rotating member.