JP5926621B2 - Lens shift mechanism and projection display device - Google Patents

Description

The present invention belongs to the technical field of a lens shift mechanism of a lens unit used for a liquid crystal projector or the like and a projection display apparatus using the same.

In general, a projection display apparatus such as a liquid crystal projector has three primary colors R using a light source such as a halogen lamp or a metal halide lamp, a liquid crystal light valve through which light projected from the light source is transmitted, and a signal output from a signal generator. The liquid crystal light valve dots arranged in a large number on each of the three liquid crystal light valves for each of the colors (red), G (green), and B (blue) are electrically switched to generate each image of the three primary colors RGB. A signal unit and a projection lens and a projection lens unit are provided for enlarging and projecting light that has passed through these liquid crystal light valves onto a screen.

Specifically, a projection display apparatus such as a liquid crystal projector includes an integrator lens for a light beam emitted as a parallel light from a light emitting unit of a light source, each dichroic mirror that selectively transmits or reflects light in different wavelength bands, Each liquid crystal light valve is guided through each total reflection mirror and each condenser lens. The light that has passed through the integrator lens is light-modulated by the liquid crystal light valve to become modulated light, and the modulated light synthesized through the dichroic prism is enlarged and projected by the projection lens unit, and is projected and displayed on the screen.

The projection display apparatus further includes a lens shift mechanism for moving the projection lens unit in the vertical direction or further in the horizontal direction. With this lens shift mechanism, the projection image can be displayed with the main body of the projection display apparatus being left as it is. Can be moved vertically or further to the left and right to adjust the position of the image relative to the screen, and the projection image can be reduced from becoming trapezoidal.

In Patent Document 1, the projection light from the light source is separated into three primary color lights by a plurality of dichroic mirrors for separation, and each color liquid crystal panel (liquid crystal light valve) is transmitted through different optical paths, and then combined. A technique relating to the position adjustment of each color light liquid crystal panel in a liquid crystal projector which is synthesized through a dichroic prism and projected through a projection lens (projection lens) is disclosed. The technique of Patent Document 1 is a technique for acquiring a signal for controlling and detecting the position of each color liquid crystal panel in parallel, and performing a liquid crystal panel adjustment assembly for adjusting the position of each color light liquid crystal panel in parallel based on the acquired signal. is there. In this technology, an image receiver for projected images, a gripping means for each liquid crystal panel, an operation means for operating the gripped liquid crystal panel on a plurality of axes, a drive control means, and information from the receiver are detected. Including a liquid crystal panel adjusting and assembling apparatus for a liquid crystal projector having an information detecting means, a calculating means for calculating an operation, and a time division control means for obtaining a detection signal of each color light in a time division manner, and maintaining high adjustment accuracy. However, this is a technique for adjusting the liquid crystal panel at high speed. This is a technique related to an optical system of a liquid crystal projector in which an image is emitted to a receiver through a projection lens.

Patent Document 2 discloses an optical system of a three-plate color liquid crystal projector in a projection-type image display apparatus that modulates light emitted from a light source with a light valve and projects an image with a projection lens unit, and a lens shift of the projection lens unit. Techniques related to the mechanism are disclosed. The optical system basically has the same configuration as the example of the liquid crystal projector disclosed in Patent Document 1. The color image light synthesized by the dichroic prism in the optical system is enlarged and projected as a color image by the projection lens unit, and is projected and displayed on the screen.

The lens shift mechanism of the projection lens unit in Patent Document 2 is configured to shift in a direction orthogonal to the optical axis thereof. The lens mounting member, the contact surface portion in contact with the lens mounting member, and the lens mounting member as the contact surface portion. It is disclosed as a technique comprising pressing means that is set so that the projection lens unit can hold the position and move its position.
The user shifts by placing a finger on the cylindrical protrusion of the cover member having a gap corresponding to the shift width of the projection lens unit and the lens barrel of the projection lens unit. By this shift operation, the lens unit is moved and held in position.

The optical system of the liquid crystal projector shown in FIG. 7 shows the configuration of the optical system of the liquid crystal projector disclosed in Patent Document 1, and exemplifies the optical system of a three-plate color liquid crystal projector.

In FIG. 7, the optical system of the liquid crystal projector includes a light source 1 such as a halogen lamp or a metal halide lamp, liquid crystal panels (liquid crystal light valves) 9, 10, 11 through which light projected from the light source 1 passes, and these liquid crystals. A projection lens 13 is provided for enlarging and projecting light that has passed through the panels 9, 10, and 11. This liquid crystal projector is a color liquid crystal projector, and is a three-plate type in which liquid crystal panels are provided for light of the three primary colors of R (red), G (green), and B (blue). The modulated light is synthesized by the dichroic prism 12. In order to guide the light from the light source 1 to the projection lens 13, the housing 14 includes a dichroic mirror 4, 6, a dichroic prism 12, a total reflection mirror, various lenses, which split the light from the light source into R, G, B colors. Etc. are deployed.

The light from the light source 1 is reflected by the total reflection mirror 3, the dichroic mirror 4 transmits one of the three primary colors (red (R)), and the remaining two colors of light are reflected. The transmitted red light is reflected by the total reflection mirror 5 and enters the liquid crystal panel 10. On the other hand, the remaining two colors of light reflected by the dichroic mirror 6 reflect one color (green (G)) and transmit the other color (blue (B)). The reflected green light is incident on the liquid crystal panel 9. The transmitted blue light is reflected by the total reflection mirrors 7 and 8 and enters the liquid crystal panel 11. The light of each color that has passed through each liquid crystal panel 9, 10, 11 is combined in the dichroic prism 12, and this combined light is irradiated by the projection lens 13 and projected onto the screen 15. Although the projection lens 13 is represented as a single lens in FIG. 4, it is generally composed of a plurality of lens groups as a projection lens unit.

FIG. 6 is a diagram showing a lens shift mechanism of the projection lens unit 115 exemplified as the prior art in Patent Document 2, and a perspective view showing the lens shift mechanism for moving the projection lens unit 115 in the vertical direction. It is. 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 becoming trapezoidal.

  Sliding bearings 121 a are provided at the four corners of the moving base 121 to which the projection lens unit 115 is fixed. A guide shaft 122 is inserted into the sliding bearings 121 a, and the moving base 121 is guided along the guide shaft 122 in the vertical direction. Is done. A plate member 121 b is fixed to the side portion of the moving base 121. The plate member 121b is formed with a screw hole, 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 shaft 122 is fixed to the fixed base 129 by a bearing 124 so that vertical movement or the like does not occur. 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.

JP 2004-347803 A JP 2003-315917 A

In the lens shift mechanism shown in FIG. 6, in order to smoothly move the moving base 121 up and down, the guide shaft 122 is made of a metal that is not easily rusted and is ground smoothly. 121a uses a wear-resistant resin or an oilless bearing. 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, and if these tolerances are reduced, they move due to component variations and cumulative errors. There arises a problem that the base 121 cannot be raised and lowered smoothly.

As described above, the lens shift mechanism of the projection lens unit used in the liquid crystal projector has a projection lens in a direction perpendicular to the optical axis of the color image light with respect to the dichroic prism that emits the color image light in the position adjustment of the projection image. Although it was a mechanism to shift the unit in parallel, the lens shift operation becomes unstable due to backlash between parts in the lens shift mechanism, causing a problem that the lens shift operation becomes oblique or swings to the left and right. There was a problem. The shift dial of the lens shift mechanism is not located at the center of the lens shift mechanism, but is provided at the end, so that the guide shaft on the access point side of the lens shift operation moves first, and the access point Since the guide shaft on the opposite side moves later, there is a problem in that it does not move smoothly on the screen at the time of projection, making it difficult to fine-tune the image position.

In view of the above-described circumstances, the present invention provides a lens shift mechanism that is less likely to be complicated in structure even when the projection lens unit is moved (shifted) in the vertical direction (up and down direction), and that can be easily shifted. An object of the present invention is to provide a projection display apparatus provided with a shift mechanism.

In order to achieve the above object, according to the present invention, a projection lens unit that shifts a projection lens unit that performs image projection in a direction orthogonal to the optical axis is provided. A fixed lens mounting member, a position movement holding member equipped with the lens mounting member and having a position movement holding mechanism capable of moving and holding the position of the lens mounting member; and the position movement holding member in the direction to the fixed flange portion for holding shiftably, and a shaft which rotates movably holding the position the movable holding member with respect to the fixed flange part, the position movement holding mechanism, the respect to the stationary flange portion characterized by comprising a vertical position moving the holding mechanism as a rotation about the axis to enable the position movement and position holding of the projection lens unit.

A feature of the present invention is that it is provided on the other end side of the position movement holding member, with one end of the position movement holding member to which the lens mounting member is attached and a shaft provided at a position facing the fixed flange portion as a rotation center. By the position movement holding mechanism, the projection lens unit is moved together with the lens mounting member in an arcuate substantially linear direction by rotation about the axis , and held, whereby the projected image is positioned on the projection screen with a simple mechanism. The A lens suitable for moving substantially parallel to a plane perpendicular to the lens optical axis with a maximum lens shift movement amount of ± 0.4 mm in the arcuate substantially linear direction at the center position of the lens optical axis and maintaining the position Shift mechanism.

Further, a vertical position movement holding mechanism for moving the position holding the vertical direction in a straight angle plane to the optical axis of the projection lens unit, the relative horizontal movement and position holding of the position movement retaining member and the lens mounting member It is the lens shift mechanism provided with the horizontal position movement holding mechanism to perform.

According to the present invention, the number of parts of the lens shift mechanism of the projection lens unit is reduced, the projection lens unit can be translated in the direction of the plane orthogonal to the optical axis of the emitted light from the dichroic prism, and the lens shift operation can be performed. An easy lens shift mechanism can be provided.

It is a perspective view which shows the liquid crystal projector of the Example of this invention. It is a perspective view which shows the structure of the mounting part of the projection lens unit of the Example of this invention. It is sectional drawing which shows the position movement holding mechanism of the projection lens unit of the Example of this invention. It is a perspective view which shows the pivot part of the projection lens unit of the Example of this invention. It is a figure which shows the relationship between the shift amount of the perpendicular direction (Y direction) by the vertical position movement holding | maintenance mechanism of the lens shift mechanism of the Example of this invention, and the deviation | shift amount of a horizontal direction (X direction). It is a figure which shows the optical system of the liquid crystal projector which concerns on a prior art and this invention. It is a figure which shows the lens shift mechanism of the projection lens unit which concerns on a prior art.

  The projection lens unit according to the present invention is configured such that, in the configuration of the optical system of the liquid crystal projector illustrated in FIG. 7, the projection lens unit can be translated in the direction of the plane orthogonal to the optical axis of the projection light from the dichroic prism and the lens shift can be performed. A lens shift mechanism that is easy to operate is provided.

An embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, FIG. 3, FIG. FIG. 1 is a perspective view showing a liquid crystal projector according to an embodiment of the present invention. In FIG. 1, a position movement holding unit including a liquid crystal projector 30, a projection lens unit 31, a projection lens unit barrel part 32, a fixing flange part 22, a lens mounting member 23, a horizontal position movement holding mechanism 24a, and a vertical position movement holding mechanism 24b. The member 24 is shown. The basic configuration of the optical system in the liquid crystal projector 30 of the present embodiment is the same as that of the liquid crystal projector shown in FIG. In the present invention, vertical means up and down directions, and horizontal means both left and right directions.

2, 3, and 4 are diagrams illustrating a mounting portion of the projection lens unit 31 according to the embodiment of the present invention. In FIG. 2, a fixed flange portion 22, a lens mounting member 23, a position movement holding member 24, a horizontal position movement holding mechanism 24 a and a vertical position movement holding mechanism 24 b provided on the position movement holding member 24, and a guide constituting the holding portion 25. The pin 25a and the guide pin fixing plate 25b are shown. The projection lens unit barrel portion 32 shown in FIG. 1 is attached to the lens mounting member 23 by screwing.

In FIG. 3, a position movement holding unit provided with a projection optical path opening 21, a fixed flange part 22, a lens mounting member 23, a horizontal position movement holding mechanism 24a and a vertical position movement holding mechanism 24b of a liquid crystal projector 30 (shown in FIG. 1). The holding part 25 for attaching the member 24 and the lens mounting member 23 (shown in FIG. 2) to the position movement holding member 24 is shown. The projection optical path opening 21 is an opening through which projection light passes. The fixed flange portion 22 is a part of the main body housing of the liquid crystal projector 30, and moves so as to hold the lens mounting member 23 to which the projection lens unit 31 is mounted so as to be parallel to a plane perpendicular to the optical axis of the projection lens unit 31. The holding member 24 is configured as a member that is held and fixed via a pivot 26.

A horizontal position movement holding mechanism 24 a including a rotation shaft 24 d and a rotation gear 24 e is attached to the other end side of the position movement holding member 24. A vertical position movement holding mechanism 24b is provided in the vicinity of the horizontal position movement holding mechanism 24a. In the present invention, the end portion of the position movement holding member 24 provided with the pivot 26 is defined as one end side, and the end portion of the position movement holding member 24 on the opposite side is defined as the other end side. The horizontal position movement holding mechanism 24a includes a rotating shaft 24d and a rotating gear 24e attached to the tip of the rotating shaft 24d, and meshes at right angles with the rotating gear 24e at an intermediate portion of a horizontal shaft 24g orthogonal to the rotating shaft 24d. The lateral gear 24f and a nut 24h are provided at the tip of the lateral shaft 24g. The nut 24h is inserted into a corresponding portion (not shown) of the lens mounting member 23. When the rotating shaft 24d rotates, the rotating gear 24e rotates, the horizontal gear 24f and the horizontal shaft 24g rotate, and the nut 24h moves in the axial direction of the horizontal shaft 24g. When the nut 24h moves in the axial direction of the horizontal shaft 24g, the lens mounting member 23 to which the nut 24h is attached and connected is shifted in the axial direction of the horizontal shaft 24g. As a result, the horizontal position movement holding mechanism 24a enables the horizontal movement of the projection lens unit 31 mounted on the lens mounting member 23 on a plane perpendicular to the optical axis. The lens mounting member 23 is slidably held by the holding member 25 with respect to the position movement holding member 24. By selecting the gear pitch of the rotary gear 24e attached to the tip of the rotary shaft 24d and the horizontal gear 24f attached to the horizontal shaft 24g and meshing with the rotary gear 24e, if it is a minute gear pitch, the rotary shaft 24d The rotation by the external force is limited, and the horizontal position movement holding member 24 can be held in the horizontal direction by the horizontal position movement holding mechanism 24a. The horizontal position movement holding mechanism 24a has a configuration provided with a position movement function and a position holding function in the horizontal direction. With this configuration, the projection lens unit 31 can be shifted in a horizontal direction parallel to a plane perpendicular to the lens optical axis.

The vertical position movement holding mechanism 24b includes a rotation shaft 24k integrated with the collar portion 24i and a nut portion 24j attached to the position movement holding member 24, and a part of the collar portion 24i of the rotation shaft 24k slides. The configuration is such that the fixed flange portion 22 and the position movement holding member 24 are moved and held by a flange sliding portion 22a provided on the fixed flange portion 22 so as to be insertable. The collar part 24i of the rotating shaft 24k is inserted into the collar part sliding part 22a. Along with the rotation of the rotation shaft 24k, the nut portion 24j attached to the position movement holding member 24 is moved in the axial direction of the rotation shaft 24k, whereby the position movement holding member 24 is rotated in an arc shape around the pivot 26. It is configured to enable vertical movement that is substantially linear movement. By selecting the thread portion pitch of the rotating shaft 24k and the nut portion 24j that is screwed into the threaded portion of the rotating shaft 24k, it is possible to set the amount of vertical movement per rotation of the rotating shaft 24k. If the pitch is small, rotation by the external force of the rotating shaft 24k is limited, and the position of the position movement holding member 24 can be held. The vertical position movement holding mechanism 24b has a configuration including a position movement function and a position holding function in the vertical direction. With this configuration, the projection lens unit 31 is perpendicular to the lens optical axis by the vertical position movement holding mechanism 24b of the position movement holding member 24 provided on the other end side with the pivot 26 provided on the one end side as the rotation center. It is possible to shift in the vertical direction in a substantially straight line that is parallel to the flat surface and arcuate.

  The holding portion 25 is a member having a function of holding the lens mounting member 23 slidably and detachably attached to the position movement holding member 24. It is provided at a plurality of locations where the fixed flange portion 22 is opposed, and is provided at three corners in this embodiment. The holding portion 25 includes a guide pin 25a and a guide pin fixing plate 25b, and is mounted so that the end portion of the lens mounting member 23 is fitted into the gap between the guide pin 25a and the mounting surface of the position movement holding member 24.

As shown in FIG. 4, the position movement holding member 24 is disposed on one end portion side where the position movement holding member 24 and the fixed flange portion 22 face each other, and the optical axis of the projection lens unit 31 of the fixed flange portion 22 is disposed. A pivot 26 is provided which is rotatably held on a plane parallel to a plane perpendicular to the plane. In the pivot 26, the shaft hole 26c provided in the fixed flange portion 22, the pivot shaft 26a press-fitted into the shaft hole 26c, and the position movement holding member 24 are separated by the thickness of the collar portion provided in the shaft 26a. A possible flange portion 26 d and a pivot shaft 26 a are rotatably fitted, and a bearing hole 26 b provided on one end portion side of the position movement holding member 24 is a basic configuration. The shaft hole 26 c and the bearing hole 26 b of the pivot 26 are not limited to the embodiment shown in FIG. 4, and can be provided on the fixed flange portion 22 and the position movement holding member 24 as having opposite configurations. As to have the opposite configuration, it is appropriately selected whether to provide a shaft hole for rotatably fitting the pivot shaft 26a in the fixed flange portion 22 and a bearing hole for press-fitting the pivot shaft 26a in the position movement holding member 24. Can do. Further, the collar portion 26d may be a rod-shaped pivot shaft 26a, and instead of providing the collar portion, a spacer having a shape such as a washer may be used.

FIG. 5 is a diagram showing an example of the shift state of the image range before and after the lens shift in the vertical direction (shown as an oblique direction in FIG. 5) by the vertical position movement holding mechanism 24b of the projection lens unit 31. It is. FIG. 5 is a diagram illustrating a relationship between a shift amount in the vertical direction (Y direction) and a shift amount in the horizontal direction (X direction) in the projection lens unit 31. The vertical direction indicates a substantially vertical movement direction that is an arcuate rotation about the pivot 26 and is substantially linear. The horizontal direction in this case is a direction perpendicular to the vertical direction, which is a substantially linear movement direction, and in the vertical movement, the horizontal direction is substantially a very small amount of movement. It becomes. In FIG. 5, the shift amount of the optical axis center portion of the projection optical path opening 21 in the fixed flange portion 22 of the projection lens unit 31 and the image before Y shift (shown by a solid line) and the image after Y shift (shown by a dotted line). Shows the relationship. The shift amount in the vertical direction of the projection lens unit 31 is required to be about ± 0.4 mm at the center of the optical axis of the projection optical path opening 21. In the case of corresponding to the shift movement amount required in the vertical direction, the movement amount in the horizontal direction (X direction) around the pivot 26 depends on the arrangement size of the pivot 26 and the vertical position movement holding mechanism 24b. However, the value is as small as ± 0.0025 mm at the center of the optical axis of the projection optical path opening 21.

Strictly speaking, since the lens mounting member 23 moves in an arc shape around the pivot 26, a movement amount (deviation) of ± 0.0025 mm in the horizontal direction is generated with respect to the movement amount of ± 0.4 mm in the vertical direction. However, in the image position adjustment, the horizontal movement amount is a numerical value that can be ignored in practice. That is, a linear shift is performed in the vertical direction, and fine position adjustment is possible. Thus, the lens shift with the pivot 26 as the rotation center in the present invention is an arc-shaped shift movement at the operating point of the vertical position movement holding mechanism 24b with the pivot 26 as the rotation center. The vertical image position adjustment in the vertical direction according to the present invention is sufficiently possible within the numerical range of the movement in the vertical direction and the amount of movement. Positional movement adjustment and position holding by movement shift of the lens unit can be reliably performed with a simple configuration.

In addition, in a projection display apparatus that modulates light emitted from a light source with a light valve and projects an image with a projection lens unit, the projection lens display unit includes the lens shift mechanism according to the present invention. A lens shift operation can be performed.

DESCRIPTION OF SYMBOLS 21 ... Projection optical-path opening part 22 ... Fixed flange part 23 ... Lens mounting member 24 ... Position movement holding member 25 ... Holding part 26 ... Pivot 30 ... Liquid crystal projector 31 ... Projection lens unit 32 ... Projection lens barrel part

Claims (4)

In a lens shift mechanism that shifts a projection lens unit that performs image projection in a direction orthogonal to the optical axis,
A lens mounting member to which the projection lens unit is fixed;
And position the movable holding member with a position moving holding mechanism, wherein the lens mounting member to allow the position holding and positional movement of the mounted and the lens mount member,
A fixed flange portion that holds the position movement holding member in a shiftable manner in the direction ;
And a shaft which rotates movably holding the position the movable holding member with respect to the fixed flange part,
The position movement holding mechanism, characterized by comprising a position movement and position holding the vertical position moving the holding mechanism to allow the projection lens unit as a rotation about the axis relative to the stationary flange portion Lens shift mechanism. The lens shift mechanism according to claim 1,
Shift amount of the projection lens unit by the vertical position moving the holding mechanism, as the center of rotation of the shaft, in a direction perpendicular to the optical axis to the optical axis on the straight corner surfaces of the projection lens unit, and the optical axis The lens shift mechanism is characterized in that the range is ± 0.4 mm. The lens shift mechanism according to claim 1 or 2,
The position movement holding mechanism, a lens shift mechanism, characterized in that it comprises a horizontal position moving the holding mechanism for the relative horizontal position movement and position holding of the lens mounting member and the position moving the holding member . In a projection display apparatus that modulates light emitted from a light source with a light valve and projects an image with a projection lens unit,
A projection image display apparatus comprising the lens shift mechanism according to claim 1.

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