JP5644142B2 - projector - Google Patents

Description

  The present invention relates to a projector that projects image light.

  An optical device that modulates a light beam emitted from a light source according to image information to form image light and a projector that includes a projection lens that projects the image light are known. In addition to the optical device and the projection lens, the projector includes a plurality of optical components and an optical component casing that places these optical components at predetermined positions on the optical path. Examples of the optical component include a dichroic mirror that separates a light beam emitted from a light source into a plurality of color lights by reflection and transmission, and a reflection mirror that reflects the separated color lights. In order to suppress unevenness in illumination, color unevenness, etc., and obtain a projected image with good image quality, there is a technology that makes it possible to adjust the tilt angle of the reflecting mirror with respect to the optical axis so as to efficiently and uniformly guide the light beam to the optical device. It has been proposed (see, for example, Patent Document 1).

  The technique described in Patent Document 1 has a holding member that holds the back side of the reflecting mirror. The holding member is provided with a spherical bulge that bulges on the opposite side of the reflecting mirror. In addition, the optical component casing is formed with a recess with which the bulging portion is engaged. The reflection mirror held by the holding member is rotated so that the bulging portion slides in the recess, and the inclination angle is adjusted.

JP 2004-205716 A

  However, although the technique described in Patent Document 1 can be applied to the reflection mirror, adjusting the tilt angle of the reflection mirror cannot efficiently guide the light beam to the optical device, and adjustment of the dichroic mirror is not possible. In the case of a required optical system, there is a problem that it cannot be applied to the dichroic mirror because the holding member blocks the transmitted light.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 A projector according to this application example reflects a light source and a predetermined color light beam out of the light beam emitted from the light source, transmits a color light different from the predetermined color light beam, and separates the light beam. An optical component housing that houses the dichroic mirror, and one end of the dichroic mirror that holds the one end of the dichroic mirror and rotates about the rotation axis that extends substantially perpendicular to the optical axis of the light beam. And a holding member that is supported, and an optical device that modulates a light beam separated by the dichroic mirror according to image information to form image light.

  According to this configuration, since the holding member holds one end of the dichroic mirror, the holding member can be configured to hold the outside of the region where the light beam of the dichroic mirror is incident. The holding member is rotatably supported by the optical component casing with a rotation axis extending substantially perpendicular to the optical axis as a center. As a result, the angle of the dichroic mirror with respect to the optical axis is adjusted with a simple configuration and an easy operation of rotating the dichroic mirror, and the colored light reflected and transmitted by the dichroic mirror can be efficiently guided to the optical device. it can. Therefore, the projector can suppress brightness unevenness, color unevenness, and the like, and project image light with good image quality.

  Application Example 2 In the projector according to the application example described above, the rotation axis passes through an intersection of the dichroic mirror and the optical axis when the dichroic mirror is inclined at a predetermined inclination angle with respect to the optical axis. Preferably, it is provided on a virtual plane orthogonal to the dichroic mirror.

  According to this configuration, the tilt angle of the dichroic mirror is changed by being rotated with the state tilted at a predetermined tilt angle set in the design as a reference state. The rotation axis is provided on a virtual plane that passes through the intersection of the dichroic mirror and the optical axis in the reference state and is orthogonal to the dichroic mirror. That is, the dichroic mirror has a symmetrical locus with respect to the virtual plane in the forward and reverse rotation from the reference state. As a result, the light beam reflected by the dichroic mirror is also reflected symmetrically, making it easy to adjust the angle of the dichroic mirror. In addition, the amount of movement of the dichroic mirror due to rotation can be reduced compared to the case where the rotation axis is not provided on this virtual plane, so the structure for fixing the adjusted dichroic mirror can be simplified, and the housing for optical components Can be miniaturized.

1 is a schematic diagram showing a schematic configuration of a projector according to an embodiment. The perspective view which incorporated the G light reflection dichroic mirror of this embodiment in the lower housing | casing. The perspective view which decomposed | disassembled the G light reflection dichroic mirror from the lower housing | casing of this embodiment. The top view which shows the G light reflection dichroic mirror in the reference | standard state of this embodiment. The perspective view which shows the holding member of this embodiment. The enlarged view of the rotating shaft vicinity in FIG. The figure explaining the adjustment method of the inclination with respect to the inclination-angle and the up-down direction of the G light reflection dichroic mirror of this embodiment.

Hereinafter, the projector according to the present embodiment will be described with reference to the drawings.
The projector according to the present embodiment modulates a light beam emitted from a light source according to image information to form image light, and projects the image light on a screen or the like.
FIG. 1 is a schematic diagram illustrating a schematic configuration of a projector 1 according to the present embodiment.
As shown in FIG. 1, the projector 1 includes an exterior housing 2 constituting an exterior, an optical unit 3 having a light source device 31, a control unit, a power supply device that supplies power to the light source device 31 and the control unit, and the interior of the projector 1. A cooling fan or the like for cooling (all not shown) is provided.

  The control unit includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and functions as a computer, and is related to control of the operation of the projector 1, for example, image projection. Control and so on.

The optical unit 3 optically processes the light beam emitted from the light source device 31 under the control of the control unit, and forms and projects image light according to image information.
As shown in FIG. 1, in addition to the light source device 31, the optical unit 3 includes an illumination optical device 32, a color separation optical device 33, an optical device 34, a projection lens 35, and these optical components 31 to 35 in a predetermined path on the optical path. An optical component housing 4 is provided at a position.

  The light source device 31 includes a discharge-type light source 311 including a super-high pressure mercury lamp and a metal halide lamp, a reflector 312 and the like. Then, the light source device 31 aligns the emission direction of the light beam emitted from the light source 311 with the reflector 312 and emits it toward the illumination optical device 32.

The illumination optical device 32 includes a first lens array 321, a second lens array 322, a polarization conversion element 323, and a superimposing lens 324.
The first lens array 321 includes a plurality of small lenses arranged in a matrix, and divides the light beam emitted from the light source device 31 into a plurality of light beams. The second lens array 322 has substantially the same configuration as the first lens array 321, and together with the superimposing lens 324, the light beam is substantially superimposed on the surface of a reflection type light modulation device 342 described later.
The polarization conversion element 323 has a function of aligning randomly polarized light emitted from the second lens array 322 with substantially one type of polarized light that can be used by the light modulation device 342.

  The color separation optical device 33 includes a cross dichroic mirror 331, a G light reflection dichroic mirror 332, and reflection mirrors 333 and 334. The light emitted from the illumination optical device 32 is converted into red light (hereinafter referred to as “R light”), green. It has a function of separating light of three colors, light (hereinafter referred to as “G light”) and blue light (hereinafter referred to as “B light”).

  The cross dichroic mirror 331 is configured by arranging a B light reflecting dichroic mirror 331B and a GR light reflecting dichroic mirror 331GR in an X shape. The cross dichroic mirror 331 reflects B light by the B light reflecting dichroic mirror 331B and reflects G light and R light by the GR light reflecting dichroic mirror 331GR out of the light flux emitted from the illumination optical device 32. Separate incident light flux.

  The B light reflected by the B light reflecting dichroic mirror 331B is reflected by the reflecting mirror 333 and emitted to an electro-optical device 340B described later. On the other hand, the G light and the R light reflected by the GR light reflecting dichroic mirror 331GR are reflected by the reflecting mirror 334 and then enter the G light reflecting dichroic mirror 332.

The G light reflecting dichroic mirror 332 is disposed to be inclined with respect to the optical axis L of the light beam reflected by the reflecting mirror 334. The G light reflecting dichroic mirror 332 reflects the G light out of the G light and R light reflected by the reflecting mirror 334, and separates the incident light beam through the R light.
The G light reflected by the G light reflecting dichroic mirror 332 is emitted to the electro-optical device 340G described later, and the R light transmitted through the G light reflecting dichroic mirror 332 is emitted to the electro-optical device 340R described later. .

  The G light reflecting dichroic mirror 332 is fixed to the optical component casing 4 after the inclination angle with respect to the optical axis L is adjusted in order to efficiently guide the light beam to the electro-optical device 340G. The fixing structure of the G light reflecting dichroic mirror 332 will be described in detail later.

  The optical device 34 includes an electro-optical device 340 provided for each of the three color lights (an electro-optical device for R light 340R, an electro-optical device for G light 340G, and an electro-optical device for B light 340B). ), And a cross dichroic prism 344 as a color synthesizing optical device. Each color light separated by the color separation optical device 33 is modulated according to image information to form image light.

  The electro-optical device 340 includes a reflective polarizing plate 341, a reflective light modulation device 342, and a polarizing plate 343.

  The reflective polarizing plate 341 has a wire grid type configuration in which a number of fine linear ribs made of aluminum or the like are arranged in parallel on a glass substrate. The reflective polarizing plate 341 transmits polarized light having a polarization direction perpendicular to the extending direction of the linear ribs, and reflects polarized light having a polarization direction parallel to the extending direction of the linear ribs.

  The reflective polarizing plate 341 is arranged at an inclination of approximately 45 ° with respect to the optical axis of the incident color light. The reflective polarizing plate 341 transmits polarized light having substantially the same polarization direction as the polarized light aligned by the polarization conversion element 323 out of the incident light beam, and reflects polarized light having a polarization direction orthogonal to the transmitted polarized light. Let In addition, a retardation plate is disposed on the upstream side of the optical path of the reflective polarizing plate 341 so that the reflective polarizing plate 341 transmits polarized light having a polarization direction different from that of the polarized light aligned by the polarization conversion element 323. Also good.

  The light modulation device 342 is disposed so as to be substantially orthogonal to the optical axis of the light beam that has passed through the reflective polarizing plate 341. The light modulation device 342 has a structure in which a liquid crystal layer is sandwiched between opposing substrates, and is configured by so-called LCOS (Liquid Crystal On Silicon). A reflective pixel electrode to which switching elements are connected is formed in a matrix on a silicon substrate, which is one substrate, and a counter electrode is formed on the other substrate (transparent substrate).

  In the light modulation device 342, a voltage is applied between the reflective pixel electrode and the counter electrode in accordance with a drive signal from the control unit, and the alignment state of the liquid crystal is controlled. Then, the light modulation device 342 modulates the polarization direction of the polarized light transmitted through the reflective polarizing plate 341 and reflects it toward the reflective polarizing plate 341. Of the light beam modulated by the light modulation device 342 and reflected toward the reflective polarizing plate 341, only the polarized light having a polarization direction orthogonal to the polarized light aligned by the polarization conversion element 323 is applied to the reflective polarizing plate 341. And reflected.

  The polarizing plate 343 transmits polarized light having the same polarization direction as that of the polarized light reflected by the reflective polarizing plate 341. That is, the polarizing plate 343 removes a polarization component other than the desired polarization component and improves the contrast of the image even when the light beam reflected by the reflective polarization plate 341 includes a polarization component other than the desired polarization light. Contribute to.

  The cross dichroic prism 344 combines the color lights modulated by the electro-optical device 340 to form image light representing a color image. The cross dichroic prism 344 has a substantially square shape in plan view in which four right-angle prisms are bonded together, and two dielectric multilayer films are formed on the interface where the right-angle prisms are bonded together. In the cross dichroic prism 344, the dielectric multilayer film reflects R light and B light modulated by the electro-optical devices 340R and 340B, transmits G light modulated by the electro-optical device 340G, and transmits each color light. Synthesize.

  The projection lens 35 is configured as a combined lens in which a plurality of lenses are combined, and enlarges and projects the image light formed by the optical device 34 on the screen.

  The optical component housing 4 has an opening on one side, a lower housing 5 (a part of which is shown in FIG. 2) that houses the above-described optical component, and an upper housing (not shown) that closes the opening. It is configured with. Optical components such as the G light reflecting dichroic mirror 332 and the reflecting mirrors 333 and 334 are fixed by inserting side end portions into grooves formed in the lower housing 5, and the optical device 34 and the projection lens 35 include a holding member and the like. And is fixed to the lower housing 5 with screws.

Here, the fixing structure of the G light reflecting dichroic mirror 332 will be described in detail.
The G light reflecting dichroic mirror 332 is disposed to be inclined with respect to the optical axis L as described above. The G light reflecting dichroic mirror 332 is configured to change the tilt angle by rotating forward and backward with a state tilted at a predetermined tilt angle set in design as a reference state.

  2 to 4 are views showing a part of the G light reflecting dichroic mirror 332 and the lower housing 5. Specifically, FIG. 2 is a perspective view in which the G light reflecting dichroic mirror 332 is incorporated in the lower housing 5, FIG. 3 is an exploded perspective view of the G light reflecting dichroic mirror 332 from the lower housing 5, and FIG. It is a top view which shows the G light reflection dichroic mirror 332 in a reference | standard state.

  In the following, for convenience of explanation, the traveling direction of the light beam reflected by the reflecting mirror 334 is orthogonal to the + X direction and the X direction, and the upper side in the drawing view of FIG. 2 is the + Z direction (upward direction), the X direction, and the Z direction. The right side in the drawing view of FIG. 2 is described as the + Y direction. That is, the ± X direction is the optical axis L direction.

  The G light reflecting dichroic mirror 332 is an optical component in which a dielectric multilayer film that reflects G light and transmits R light is formed on a transparent substrate. As shown in FIGS. It is formed into a shape. The G light reflecting dichroic mirror 332 is disposed in the lower housing 5 with the lower end center portion held by the holding member 6.

FIG. 5 is a perspective view showing the holding member 6.
The holding member 6 is formed so as to hold outside the region where the light beam of the G light reflecting dichroic mirror 332 is incident. As shown in FIG. 5, the holding member 6 has a rectangular parallelepiped guide portion 61 and a cylindrical shape from the lower surface of the guide portion 61. A protruding shaft portion 62 is provided. An insertion groove 611 that is recessed along the longitudinal direction is formed on the upper surface of the guide portion 61. The end of the G light reflecting dichroic mirror 332 is inserted into the insertion groove 611 and fixed to the holding member 6 with an adhesive.

  As shown in FIGS. 2 and 3, the lower housing 5 has a bottom surface portion 51 formed so as to substantially follow a horizontal plane, and a side surface portion 52 that stands up from an edge of the bottom surface portion 51. And the groove part 521 dented along an up-down direction is provided in the inner surface of the side part 52 which opposes, respectively, and the shaft hole 511 is provided in the bottom face part 51 between the groove parts 521 which oppose. Each of the groove 521 and the shaft hole 511 is formed so that the side end of the G light reflecting dichroic mirror 332 and the shaft 62 of the holding member 6 can be inserted in a loosely fitted state.

  The G light reflecting dichroic mirror 332 to which the holding member 6 is attached is disposed in the lower housing 5 with the side end portion inserted into the groove portion 521 and the shaft portion 62 of the holding member 6 inserted into the shaft hole 511. The G light reflecting dichroic mirror 332 extends in the vertical direction and is supported by the lower housing 5 so as to be rotatable about the rotation shaft 6J that is the center of the shaft portion 62. That is, the G light reflecting dichroic mirror 332 is supported so as to be rotatable about the rotation axis 6J extending substantially perpendicular to the optical axis L.

  As shown in FIG. 4, the G light reflecting dichroic mirror 332 has a side end portion spaced apart from the inner surface of the groove portion 521 with a gap that can be bonded, as shown in FIG. Direction) and counterclockwise (CCW direction in the drawing view of FIG. 4). The G light reflecting dichroic mirror 332 is rotatable about the rotation shaft 6J until the side end portion comes into contact with the inner surface of the groove portion 521.

FIG. 6 is an enlarged view of the vicinity of the rotating shaft 6J in FIG.
As shown in FIG. 6, the rotation axis 6 </ b> J is provided on a virtual plane VS that passes through the intersection K between the G light reflection dichroic mirror 332 and the optical axis L in the reference state and is orthogonal to the G light reflection dichroic mirror 332. .

  As shown in FIG. 6, the G light reflecting dichroic mirror 332 is arranged with an inclination angle θ that is an acute angle with respect to the optical axis L when viewed from the direction of the rotation axis 6J in the reference state. When the G light reflecting dichroic mirror 332 is rotated in the CW direction, the inclination angle θ increases, and when the G light reflecting dichroic mirror 332 is rotated in the CCW direction, the inclination angle θ decreases. The light beam reflected by the G light reflecting dichroic mirror 332 is reflected in a direction corresponding to the tilt angle θ. The G light reflecting dichroic mirror 332 has a symmetrical locus with respect to the virtual plane VS in forward and reverse rotation from the reference state.

  Although illustration is omitted, since the shaft portion 62 of the holding member 6 is inserted into the shaft hole 511 in a loosely fitted state, the G light reflecting dichroic mirror 332 is inclined with respect to the vertical direction within a range where it does not bend. Can also be adjusted.

Here, a procedure for fixing the G light reflecting dichroic mirror 332 will be described.
The G light reflecting dichroic mirror 332 is adhesively fixed to the lower housing 5 after the inclination angle θ and the inclination with respect to the vertical direction are adjusted.
FIG. 7 is a diagram illustrating a method of adjusting the tilt angle θ of the G light reflecting dichroic mirror 332 and the tilt with respect to the vertical direction.

  As shown in FIG. 7, the G light reflecting dichroic mirror 332 is held at the upper end by the jig 10, and the inclination is adjusted by the rotation and movement of the jig 10. Specifically, the G light reflecting dichroic mirror 332 adjusts the inclination angle θ by rotating the jig 10 around the rotation axis 6J while observing the reflected light beam.

  Similarly, the G light reflecting dichroic mirror 332 is inclined with respect to the vertical direction by moving the jig 10 in the forward and reverse directions substantially orthogonal to the G light reflecting dichroic mirror 332 while observing the reflected light beam. Adjustments are made.

The G light reflecting dichroic mirror 332 is fixed to the lower housing 5 by adhering the side end portion to the groove portion 521 after adjusting the inclination angle θ and the inclination with respect to the vertical direction.
In this way, the G light reflecting dichroic mirror 332 is held at the one end of the holding member 6 and is rotatably disposed in the optical component casing 4, and the inclination with respect to the optical axis L is adjusted.

As described above, according to the projector 1 of the present embodiment, the following effects can be obtained.
(1) The inclination angle θ of the G light reflecting dichroic mirror 332 with respect to the optical axis L is adjusted by a simple configuration including the holding member 6 and an easy operation of rotating the G light reflecting dichroic mirror 332 to reflect the G light. The G light reflected by the dichroic mirror 332 and the R light transmitted therethrough can be efficiently guided to the electro-optical device 340. Therefore, the projector 1 can suppress brightness unevenness, color unevenness, and the like, and project image light with good image quality.

  (2) The G light reflection dichroic mirror 332 has a symmetrical locus with respect to the virtual plane VS in forward and reverse rotation from the reference state. As a result, since the light beam reflected by the G light reflecting dichroic mirror 332 is also reflected symmetrically, the inclination angle θ can be easily adjusted. Further, since the amount of movement of the G light reflecting dichroic mirror 332 due to rotation can be made smaller than when the rotation shaft 6J is not provided on the virtual plane VS, a simple structure in which the groove 521 is formed and bonded and fixed. Thus, the adjusted G light reflecting dichroic mirror 332 can be fixed and the optical component housing 4 can be downsized.

  (3) Since the shaft portion 62 is inserted in the shaft hole 511 in a loosely fitted state, the G light reflecting dichroic mirror 332 can be adjusted even in the vertical direction. Therefore, the G light reflected by the G light reflecting dichroic mirror 332 and the transmitted R light can be guided to the electro-optical device 340 more efficiently.

(Modification)
In addition, you may change the said embodiment as follows.
In the above-described embodiment, the shaft portion 62 serving as the convex portion is formed in the holding member 6 and the shaft hole 511 serving as the concave portion is formed in the lower housing 5. However, the concave portion is formed in the holding member 6, and the concave portion is formed in the concave portion. An engaging convex portion may be formed in the lower housing 5 so that the holding member 6 is rotatably supported by the lower housing 5.

  The projector 1 according to the embodiment uses the reflection type light modulation device 342, but may use a transmission type light modulation device.

  Similarly to the holding member 6, a member for holding the reflection mirror 333 may be provided, and this member may be configured to be rotatably supported by the lower housing 5.

  The light source device 31 of the embodiment employs a discharge-type light source 311, but is configured by various solid light emitting elements such as a laser diode, an LED (Light Emitting Diode), an organic EL (Electro Luminescence) element, and a silicon light emitting element. May be.

  DESCRIPTION OF SYMBOLS 1 ... Projector, 3 ... Optical unit, 4 ... Optical component housing | casing, 5 ... Lower housing | casing, 6 ... Holding member, 6J ... Rotating shaft, 34 ... Optical apparatus, 62 ... Shaft part, 311 ... Light source, 332 ... G Light reflecting dichroic mirror, 340, 340R, 340G, 340B ... electro-optical device, 341 ... reflective polarizing plate, 342 ... light modulator, 343 ... polarizing plate, 344 ... cross dichroic prism, 511 ... shaft hole, 521 ... groove, K: intersection, L: optical axis, VS: virtual plane, θ: inclination angle.

Claims (4)

A light source;
A dichroic mirror that reflects a predetermined color light out of the light flux emitted from the light source, transmits a color light different from the predetermined color light, and separates the light flux;
An optical component housing that houses the dichroic mirror;
A holding member that holds one end of the dichroic mirror and is rotatably supported by the optical component casing around a rotation axis extending substantially perpendicular to the optical axis of the light beam;
An optical device that modulates a light beam separated by the dichroic mirror according to image information and forms image light;
With
A projector, wherein a side end portion intersecting with one end side of the dichroic mirror is bonded and fixed to a groove portion provided in the optical component casing. The projector according to claim 1,
The projector is characterized in that the center part of the end of the dichroic mirror is held by the holding member. The projector according to claim 1 or 2 , wherein
The holding member includes a rectangular parallelepiped guide portion, a cylindrical shaft portion protruding from the guide portion, and an insertion groove provided on a surface opposite to the shaft portion of the guide portion,
An end portion of the dichroic mirror is inserted into the insertion groove and fixed by an adhesive member. The projector according to claim 3,
The projector according to claim 1, wherein the shaft portion of the holding member is inserted in a shaft hole provided in the optical component housing in a loosely fitted state and can be adjusted with respect to the inclination in the rotation axis direction.

Images