JP2007322535A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a projector capable of restraining stray light from being caused by the off-light of a DMD and also preventing the stray light caused by the off-light or the like from being made incident on a projection lens. <P>SOLUTION: The projector includes: a D cut 37 formed from a first surface 34a to a second surface 34b of a light shielding plate 34 which intercepts the off-light of the DMD 30g so that the off-light may not be made incident on the projection lens 30a; and a D cut 38 arranged nearer to the projection lens 30a than the first surface 34a and the second surface 34b and formed on the third surface of the light shielding plate 34 which intercepts the stray light so that the stray light may not be made incident on the incident port of the projection lens 30a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a projector, and more particularly to a DLP (Digital Light Processing) type projector using a DMD (Digital Mirror Device).

  2. Description of the Related Art Conventionally, a projector includes a plurality of micromirrors, and each micromirror is driven in a time-sharing manner based on video data so that a video corresponding to the video data can be projected onto a screen. A so-called DLP projector having a Mirror Device is known.

  In a projector using such a DMD, off-light that reflects light in a direction other than the projection lens when the DMD is off, or light other than light that has reached through a regular route from the light source to the projection lens is incident on the projection lens. There is incident stray light. When these off-light and stray light are incident on the projection lens, the contrast of the image is lowered.

  As a technique for shielding off-light and stray light without reducing the contrast of the image, Patent Document 1 includes a plurality of diaphragms along the optical axis direction, and a diaphragm for adjusting the amount of light passing through the projection optical system. It is provided with a device, and is arranged so that projection light passing through one diaphragm located on the front side in the optical axis direction is not shielded by other diaphragms located on the rear side in the optical axis direction from this diaphragm. A projection lens device and a projector device are disclosed.

Further, Patent Document 2 discloses a projection type in which a light-absorbing element having an opening is arranged on the front surface of a light valve so that reflected light of unnecessary illumination light that is incident outside the effective display area of the light valve is not emitted to the screen side. A display device is disclosed. Patent Document 3 discloses that the DMD cover disposed between the DMD and the projection lens in order to protect the DMD from light heat is heated by the DMD off-light and is not destroyed. An image display projector in which a notch is provided at a position where the light is irradiated is disclosed. Further, Patent Document 4 discloses a projection display device in which the shape of the light-shielding portion of the stop is non-rotationally symmetric with respect to the optical axis in the illumination light path to the reflective light valve.
JP 2006-11313 A JP 2004-126264 A Utility model registration No. 3092509 Republished patent WO2002 / 088841

  In the technique described in Patent Document 1 described above, two diaphragms are arranged in the reflection direction of the off-light from the DMD, but in this arrangement, two pieces of stray light that passes a lot on the side where the off-light is reflected are arranged. The idea is that the two stop plates are used to shield stray light. Patent Documents 2 to 4 do not correspond to DMD off-light, stray light generated by the off-light, or the like.

  The present invention has been made in view of the above problems, and is a projector that can suppress generation of stray light due to off-light of the DMD and prevent incidence of stray light generated by the off-light to the projection lens. For the purpose of provision.

  In order to solve the above problems, in a projector according to the present invention, a light source that generates light, a projection lens that projects incident light having a substantially circular incident port, and incident light that is incident on the projection lens A mirror surface composed of a plurality of micromirrors that can be switched between an on state that reflects toward the light source and an off state that reflects incident light in a direction other than the projection lens. A DMD in which a micromirror is driven in a time-sharing manner, and an optical engine for condensing light from the light source on the mirror surface of the DMD, generating an image based on an input image signal, and displaying the image on a screen In the projector for projecting and displaying, the stray light is formed so as to have an end corresponding to the chord with respect to the substantially circular shape of the entrance and a surface extending from the same end to the inferior arc side with respect to the substantially circular shape. A first black light-shielding plate that shields light so that it does not enter the projection lens, and is arranged closer to the DMD than the first light-shielding plate, and shields and shapes light incident on the DMD from the light source An opening having a possible opening, and an end that is substantially collinear with the end of the first light shielding plate when viewed from the projection lens, and extends in the same direction as the surface from which the first light shielding plate extends. And a surface black second light-shielding plate that allows the DMD on-light to pass therethrough while blocking off the DMD off-light from entering the projection lens.

In order to achieve the above object, the projector according to the present invention includes a light source that generates light, a projection lens that projects incident light having a substantially circular incident port, and a plurality of micromirrors. An input video signal comprising: a DMD having a mirror surface, each micromirror being driven in a time-sharing manner based on a video signal; and an optical engine for condensing light from the light source on the mirror surface of the DMD. In a projector that generates an image based on the image and projects and displays the image on a screen or the like, a first light-shielding plate that shields stray light from entering the projection lens, and the DMD closer to the DMD than the first light-shielding plate And a second light shielding plate that shields the off light of the DMD from entering the projection lens.
That is, the off-light of the DMD is shielded by the second light shielding plate and does not directly enter the projection lens. In addition, stray light reflected / scattered on the surface other than the mirror surface of the DMD, or stray light generated when light shielded by the first shielding plate is reflected / scattered on the surface of the first shielding plate, These are shielded by the first light shielding plate. Therefore, the off-light and stray light can be efficiently blocked, more off-light and stray light can be blocked, the stray light reaching the projection lens is reduced, and the projection lens passes through the regular route from the projection lens. The contrast of the projected image can be improved.

  As described above, according to the present invention, the DMD off-light is shielded by the second light-shielding plate, so that it does not enter the projection lens directly, and the stray light is shielded by the first light-shielding plate. To provide a projector capable of reducing the stray light reaching the projection lens because it can efficiently block light and improving the contrast of the image projected from the projection lens through a regular route. Can do.

According to the invention of claim 3, the light shielded by the second light shielding plate is hardly reflected or scattered, and stray light generated on the surface of the second light shielding plate can be reduced. Therefore, the occurrence of stray light due to the DMD off-light can be suppressed.
According to the fourth aspect of the invention, the emission direction of the DMD off-light and the direction in which stray light generated by the off-light being shielded by the second light-shielding plate generally coincides with each other. By matching the extended surface of the second light shielding plate with the extended surface of the first light shielding plate, the light shielding rate of stray light by the first light shielding plate is increased.
In addition, since the end formed on the second light shielding plate and the end formed on the first light shielding plate are made to be the same straight line when viewed from the projection lens, the first light shielding plate blocks the on-light of the DMD. It will not be done. Therefore, the stray light blocking efficiency by the first light blocking plate is increased, and the on-light blocking can be minimized and the contrast of the image can be improved.
Furthermore, it is needless to say that in a more specific configuration as in claim 1, the same effects as those of the inventions of claims 2 to 4 described above can be obtained.

Hereinafter, embodiments of the present invention will be described in the following order.
(1) Configuration of the projector:
(2) Structure of light shielding plate:
(3) Summary:

(1) Configuration of the projector:
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.
FIG. 1 is an external perspective view of the projector 10 according to the present embodiment as seen from an oblique direction. The projector 10 is a device that generates an image based on image data input from a personal computer, a video camera, or the like, and projects and displays the image on a screen or the like. The projector 10 projects the projection lens 30a for projecting an image on the front surface of the housing 12 and the air used for cooling the optical engine 30 and the light source device 32 provided in the housing 12 from the inside of the housing 12 to the outside. And a blowout port 12a for discharging.

  FIG. 2 is a top view schematically showing the inside of the housing 12 of the projector 10 shown in FIG. In the figure, a light source device 32 capable of generating white light is provided at one front end inside the housing 12 (upper right side in FIG. 2). The white light generated by the light source device 32 is irradiated toward the optical engine 30 installed at the other end (upper left side in FIG. 2). The optical engine 30 includes a DMD (Digital Mirror Device) 30g as an image generating element, a projection lens 30a, and the like. The optical engine 30 generates image light from the light generated by the light source device 32, and outputs the image light to the screen. Perform projection. Behind, an input / output board 18 having input / output terminals for inputting video data and inputting / outputting data signals, and a power source that can supply various commercial voltages by supplying commercial power from the outside. A substrate 20 is provided, and a video signal processing substrate 16 for controlling the DMD and the color foil based on the input video signal is arranged upright in the center.

  Next, the optical engine 30 and the light source device 32 will be described in detail with reference to FIGS. 3 is a top view of the optical engine 30 and the light source device 32 as viewed from above, FIG. 4 is a front view of the optical engine 30 and the light source device 32 as viewed from the front, and FIG. It is the right view which showed the apparatus 32 seeing from the right side.

  The optical engine 30 is roughly composed of a color foil 30b having a disk-shaped color filter, a light tunnel 30c formed by laminating four plate glasses into a cylindrical shape, a doublet lens 30d in which two lenses are combined, A mirror 30e that reflects light, a relay lens 30f that is a convex lens that collects light, a light shielding plate 34 that is disposed between the DMD and the projection lens and adjacent to the DMD, and a plurality of micromirrors. DMD 30g to be projected and a projection lens 30a for projecting light onto an external screen or the like. The light source device 32 roughly removes infrared rays and ultraviolet rays from the lamp 32a that reflects and condenses the light from the same point light source as a point light source such as a short arc lamp in a predetermined direction, and the light emitted from the lamp 32a. It is comprised from the cover glass 32b. The light source device 32 corresponds to a light source.

  The lamp 32a includes a point light source that generates white light and a parabolic reflector that reflects light emitted backward from the same point light source, and the light generated by the point light source is lighted through the color foil 30b. The light is emitted toward the entrance of the tunnel 30c. As the point light source, for example, a halogen lamp, a metal halide lamp, a high-pressure mercury lamp, a xenon lamp, or the like can be used. Moreover, as a reflector, it is possible to use a parabolic mirror, an ellipsoidal mirror, etc., for example.

  The color foil 30b has a substantially disk shape in which three color filters of RGB capable of transmitting light are arranged at equal intervals, and the surface of the disk is located in the optical path from the light source device 32 to the light tunnel 30c. By rotating the color foil 30b, the white light emitted from the light source device 32 is converted into light in which each color of RGB repeats every unit time. Of course, the color foil 30b may use a 4-segment color filter in which white (transparent) is added in addition to RGB in order to improve contrast and white brightness, or yellow (Y) and magenta (in RGB). M) and cyan (C) may be added to obtain six colors.

  The light tunnel 30c is a columnar body having a substantially rectangular shape in cross section, and guides the light separated by the color foil 30b to the mirror 30e in the subsequent stage. The doublet lens 30d is for condensing the light from the light tunnel 30c onto the mirror 30e, and corrects the defocus (axial chromatic aberration) due to the wavelength of visible light with respect to the light from the light tunnel 30c. Condensate. The mirror 30e reflects the light emitted from the doublet lens 30d. The relay lens 30f condenses the light reflected from the mirror 30e on the DMD 25.

  The DMD 30g includes a mirror surface composed of a plurality of micromirrors as modulation elements that modulate each RGB light for each pixel in accordance with image data. Each micromirror is a video signal processing board 16 or the like. It is individually controlled based on a video signal input from the outside. Then, when the angle of the reflecting surface is inclined by a predetermined angle (for example, +12 degrees and −12 degrees), light that is incident from the light source device 32 through the mirror 30e or the like is reflected toward the projection lens 30a, and the light Is switched to an off state in which the light is reflected in a direction other than the projection lens 30a. Specifically, in FIGS. 3 to 4, the mirror surface is turned on when the mirror surface is tilted in the lower right front direction around the axis extending from the upper right direction to the lower left direction on the mirror surface of the DMD 30 g, and the mirror surface is in the upper left rear direction. Turns off when tilted. Hereinafter, light reflected by the on-micromirror is referred to as on-light, and light reflected by the off-micromirror is referred to as off-light.

  As a result, the DMD 30g drives the mirror 30e in a time-sharing manner based on the RGB signals, and changes the brightness of the reflected light. That is, the DMD 30g reflects the projection light toward the projection lens 30a while processing the projection light so as to form a predetermined image. Accordingly, light that is incident from the relay lens 30f is reflected toward the entrance of the projection lens 30a through an opening 35 of the light shielding plate 34, which will be described later, while light that is incident from the relay lens 30f is incident on the projection lens 30a when it is off. Since the light is reflected in the direction away from the mouth, it is not directly incident on the projection lens 30a.

  The projection lens 30a has a substantially circular entrance, and a plurality of condensing elements are arranged along the optical axis direction in order to prevent blurring of the projected image caused by chromatic aberrations of RGB color lights. It is configured as a combined lens. Then, the image light (ON light) modulated by the DMD 30g is incident on the entrance, and the incident light is projected from the exit and enlarged and projected onto the screen.

(2) Structure of light shielding plate:
The structure of the light shielding plate and the optical path of light shielded and shaped by the light shielding plate will be described with reference to FIGS. 6, 7, 8 and 9. FIG. 6 is a perspective view showing the light shielding plate 34 as viewed from an oblique direction, FIG. 7 is a plan view showing the light shielding plate 34 as seen from the projection lens 30a side, and FIG. 8 shows the light shielding plate 34 as seen from the DMD 30g side. FIG. 9 is a cross-sectional view showing a cross section cut in the front-rear direction from AA ′ in FIG. 7 or FIG.

  The following description is on-light emitted from the projection lens 30a through the light source device 32, the color foil 30b, the doublet lens 30d, the mirror 30e, the relay lens 30f, and the DMD 30g in this order, unless otherwise specified. It is about light passing through the so-called regular route. In other words, unless otherwise specified, DMD 30g reflects off-light reflected in a direction different from the entrance of projection lens 30a, and unnecessary light that is unintentionally reflected or scattered on the surface of each member. It is not about (stray light).

  The light shielding plate 34 is obtained by anodizing an aluminum plate material to make the surface black by anodic oxidation, and then blasting to roughen the surface. In general, the light shielding plate 34 emits light from the relay lens 30f to the DMD 30g. A first surface 34a formed as a surface substantially perpendicular to the optical axis of the light, a second surface 34b formed as a surface substantially perpendicular to the optical axis of the projection lens 30a and continuous from the first surface 34a, A third surface 34c formed as a surface substantially parallel to the second surface 34b at a position offset from the second surface 34b toward the projection lens 30a, and a second position at a position off the optical path of the optical engine 30. It comprises an attachment surface 34d for connecting the surface 34b and the third surface 34c and fixing the light shielding plate 34 to the housing 12 by screwing or the like. The first surface 34a and the second surface 34b correspond to the second light shielding plate, and the third surface 34c corresponds to the first light shielding plate.

  The light shielding plate 34 has an opening 35 that can be shaped by shielding light from the first surface 34a to the second surface 34b. The opening 35 roughly reflects the light that is reflected from the relay lens 30f when the micromirror of the DMD 30g is turned on, and a substantially rectangular first region 35a that shapes the light to fit the surface of the DMD 30g. In order to cut off the off-light reflected when the micromirror of the DMD 30g is off and the second area 35b provided to reach the projection lens 30a, the D-cut 37 is matched with the direction in which the light is reflected. And a third region 35c in which is formed.

  The light reaching the light-shielding plate 34 from the relay lens is cut into a linear shape on the lower side and the left and right sides by the first region 35a of the opening 35, and is irradiated onto the mirror surface of the DMD 30g. The lower side of the light and both the left and right sides fit inside the mirror surface. That is, the light shielding plate 34 shields the light emitted from the relay lens 30f so that the upper end and the left and right ends of the light projected on the mirror surface of the DMD 30g substantially coincide with the shape of the substantially rectangular mirror surface, and the DMD 30g. The light reaching the DMD 30g is shaped by making the light projected onto the mirror surface substantially coincide with the shape of the substantially rectangular mirror surface. Here, “within the mirror surface” means that the micromirror located at the end of the mirror surface does not have to be irradiated with light, and even so that the light does not strike a portion where the mirror surface does not exist. The image formed by the micromirror located at the end of the mirror surface may be cut image light. In this way, the light emitted from the light source device 32 to the DMD 30g through the regular route reaches only below the mirror surface and inside the left and right outer ends.

  The light reflected when the micromirror of the DMD 30g is on is cut off from the upper light by the upper end of the second region 35b, and the lower light and the left and right light are separated by the first region 35a. Along with being cut, the top, bottom, left and right are cut and shaped into light having a substantially rectangular cross section.

  Further, a D-cut 38 is formed on the third surface 34c of the light shielding plate 34 so as to cross the upper left portion of the incident surface of the projection lens 30a from the upper right to the lower left as shown in FIG. The D cut is formed so as to have an end corresponding to the chord with respect to the substantially circular shape of the incident port of the projection lens 30a and a surface extending from the same end to the inferior arc side with respect to the substantially circular shape. When any one of the micromirrors of the DMD 30g is off, the off-light reflected by the micro-mirror may hit other member surfaces such as the inner surface of the optical engine 30 and become unnecessary light (stray light). Moreover, the light irradiated to the area | region in which the mirror surface 30g1 of DMD30g is not formed may reflect, and it may become unnecessary light (stray light). In order to prevent the unnecessary light from entering the projection lens 30a, the D cut 38 is formed at a position where the unnecessary light is cut.

  As shown in FIGS. 7 and 8, the D-cut 37 and the D-cut 38 are formed in the same straight line when viewed from the rear of the projection lens 30a. 38 is a position that cannot be seen. Further, even when the entrance of the projection lens 30 a is viewed from behind the light shielding plate 34, the D cut 37 and the D cut 38 are formed in the same straight line, and therefore the D cut 38 overlaps with the D cut 27 and cannot be seen. Position. That is, an end that is substantially collinear with the end of the first light shielding plate when viewed from the projection lens 30a and a surface that extends from the same end in the same direction as the surface of the first light shielding plate are formed. Is done.

  That is, when any of the micromirrors of the DMD 30g is off, the off-light reflected by the micromirror is cut and absorbed by the D-cut 37 because the light shielding plate 34 is black, and is hardly reflected / scattered. Does not generate light. Even if reflection / scattering occurs, the light is reflected / scattered in the back direction of the optical engine 30, so that the amount of unnecessary light reaching the entrance of the projection lens 30 a is very small. Therefore, when any one of the micromirrors of the DMD 30g is off, it can be avoided that the off-light reflected by the micromirror hits other member surfaces such as the inner surface of the optical engine 30. Together with the light shielding effect, it is possible to prevent unnecessary light from entering the projection lens 30a. Furthermore, since the D-cut 37 and the D-cut 38 are formed in the same straight line when viewed from the rear of the projection lens 30a, the ON light reaching the entrance of the projection lens 30a through the regular route is prevented. Absent.

  That is, the white light generated by the light source device 32 is incident on the light tunnel 30c as light in which each color of RGB is repeated per unit time by the color foil 30b, and is guided to the doublet lens 30d. The doublet lens 30d is guided to the mirror 30e while correcting the axial chromatic aberration, and the light reflected by the mirror 30e is condensed toward the DMD 30g by the relay lens 30f.

  The light emitted from the relay lens 30f is linearly cut by the light shielding plate 34 so that the lower end of the light applied to the DMD 30g is inside the lower end of the mirror surface of the DMD 30g. The right end of the light irradiated to the DMD 30g is located inside the right end of the mirror surface of the DMD 30g and the left end of the light irradiated to the DMD 30g is DMD 30g. It is shaped so as to be inside the left end of the mirror surface. That is, the light emitted from the light source device 32 to the DMD 30g reaches only the inner side from the outer end of the mirror surface.

  Then, the ON light reflected on the DMD 30g micromirror is turned on by the light shielding plate 34 so that the light on the upper side surface is cut into a linear shape and is incident on the projection lens 30a. The image is projected on a screen by a projection lens. At this time, the D-cut 37 and the D-cut 38 are formed in the same straight line when viewed from the rear of the projection lens 30a, and prevent the on-light reaching the projection lens 30a from the mirror surface 30g1 of the DMD 30g through the regular route. There is no.

  On the other hand, the on-light reflected by the off-mirrors of the DMD 30g is blocked by the D-cut 37 of the light shielding plate 34, and since the light shielding plate 34 is black, it is absorbed by the surface of the light shielding plate 34 and is reflected / reflected. Little scattering occurs. Even if slight reflection / scattering occurs, the projection lens 30a cuts off the D-cut 38 formed on the third surface 34c.

(3) Summary:
That is, the D-cut 37 formed from the first surface 34a to the second surface 34b of the light shielding plate 34 that shields off light from the DMD 30g so as not to enter the projection lens 30a, the first surface 34a, and the second surface 34b. A D-cut 38 is provided on the third surface of the light shielding plate 34 that is disposed closer to the projection lens 30a than the surface 34b and shields stray light from entering the entrance of the projection lens 30a.

As described above, in the projector corresponding to the present embodiment, a light source that generates light, a projection lens that projects incident light having a substantially circular incident port, and a mirror surface including a plurality of micromirrors A DMD in which each micromirror is driven in a time-sharing manner based on a video signal, and an optical engine that focuses the light from the light source on the mirror surface of the DMD, and based on the input video signal In a projector that generates an image and projects and displays the image on a screen or the like, a first light shielding plate that shields stray light from being incident on the projection lens, and a position closer to the DMD than the first light shielding plate And a second light-shielding plate that shields the DMD off-light from entering the projection lens.
That is, the off-light of the DMD is shielded by the second light shielding plate and does not directly enter the projection lens. In addition, stray light reflected / scattered on the surface other than the mirror surface of the DMD, or stray light generated when light shielded by the first shielding plate is reflected / scattered on the surface of the first shielding plate, These are shielded by the first light shielding plate. Therefore, the off-light and stray light can be efficiently blocked, more off-light and stray light can be blocked, the stray light reaching the projection lens is reduced, and the projection lens passes through the regular route from the projection lens. The contrast of the projected image can be improved.

  The second light shielding plate may be black on the surface. By making the surface black, the light shielded by the second light shielding plate is hardly reflected and scattered, and stray light generated on the surface of the second light shielding plate can be reduced. Therefore, the occurrence of stray light due to the DMD off-light can be suppressed.

Further, the first light shielding plate is formed to have an end corresponding to the chord with respect to the substantially circular shape of the entrance and a surface extending from the same end to the inferior arc side with respect to the substantially circular shape. The plate has an end that is substantially collinear with the end of the first light shielding plate when viewed from the projection lens, and a surface that extends from the same end in the same direction as the surface of the first light shielding plate. It may be formed.
That is, the emission direction of the DMD off-light and the direction in which stray light generated when the off-light is shielded by the second light-shielding plate generally coincide with each other. By matching the projected surface with the surface on which the first light shielding plate extends, the stray light shielding rate by the first light shielding plate is increased. In addition, the end formed on the second light-shielding plate and the end formed on the first light-shielding plate are made to be the same straight line when viewed from the projection lens. The ON light is not shielded. Therefore, the stray light blocking efficiency by the first light blocking plate is increased, and the on-light blocking can be minimized and the contrast of the image can be improved.

  Based on the above configuration, in the projector according to the present embodiment, the light source that generates light, the projection lens that projects the incident light having a substantially circular incident port, and the incident light that Based on video data, which has a mirror surface composed of a plurality of micromirrors that can be switched between an on state reflecting toward the projection lens and an off state reflecting incident light in a direction other than the projection lens. A DMD in which each micromirror is driven in a time-sharing manner, and an optical engine for condensing the light from the light source on the mirror surface of the DMD, and generates an image based on an input video signal. In a projector for projecting and displaying on a screen or the like, the projector is formed to have an end corresponding to a string with respect to the substantially circular shape of the entrance, and a surface extending from the same end to the inferior arc side with respect to the substantially circular shape. Is arranged closer to the DMD than the first light-shielding plate and shields light incident on the DMD from the light source. An opening that can be shaped, an end that is substantially collinear with the end of the first light shielding plate when viewed from the projection lens, and the same direction as the surface from which the first light shielding plate extends. And a surface black second light-shielding plate that allows the DMD on-light to pass through while being shielded so that the off-light of the DMD does not enter the projection lens.

Needless to say, the present invention is not limited to the above embodiments. It goes without saying for those skilled in the art,
・ Applying mutually interchangeable members and configurations disclosed in the above embodiments by appropriately changing the combination thereof.− Although not disclosed in the above embodiments, it is a publicly known technique and the above embodiments. The members and configurations that can be mutually replaced with the members and configurations disclosed in the above are appropriately replaced, and the combination is changed and applied. It is an embodiment of the present invention that a person skilled in the art can appropriately replace the members and configurations that can be assumed as substitutes for the members and configurations disclosed in the above-described embodiments, and change the combinations and apply them. It is disclosed as.

1 is an external perspective view of a projector according to an embodiment. It is a top view which shows typically the housing inside of a projector. It is the top view which looked at the optical engine and the light source device as seen from above. It is the front view which looked and showed the optical engine and the light source device from the front. It is the right view which showed the optical engine and the light source device from the right side. It is a perspective view of a light-shielding plate. It is the top view which showed the light-shielding plate seeing from the projection lens side. It is the top view which looked at the light-shielding plate seeing from the DMD side. FIG. 9 is a cross-sectional view showing a cross section cut in the front-rear direction from A-A ′ in FIG. 7 or FIG. 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Projector 12 ... Case 16 ... Video signal processing board 18 ... Input / output board 20 ... Power supply board 30 ... Optical engine 30a ... Projection lens 30b ... Color foil 30c ... Light tunnel 30d ... Doublet lens 30e ... Mirror 30f ... Relay lens 30g ... DMD
30g1 ... mirror surface 32 ... light source device 32a ... lamp 32b ... cover glass 34 ... light shielding plate 34a ... first surface 34b ... second surface 34c ... third surface 34d ... mounting surface 35 ... opening 35a ... first region 35b ... second region 35c ... third region 37 ... D cut 38 ... D cut

Claims (4)

A light source that generates light;
A projection lens for projecting incident light having a substantially circular entrance;
It has a mirror surface composed of a plurality of micromirrors that can be switched between an on state in which incident light is reflected toward the projection lens and an off state in which incident light is reflected in a direction other than the projection lens. DMD in which each micromirror is driven in a time division manner based on video data;
An optical engine for condensing the light from the light source on the mirror surface of the DMD;
A projector that generates a video based on an input video signal and projects and displays the video on a screen or the like.
The entrance has an end corresponding to the chord with respect to the substantially circular shape, and a surface extending from the same end to the inferior arc side with respect to the substantially circular shape, and has a black surface to shield stray light from entering the projection lens. A first shading plate,
The first light-shielding plate is disposed closer to the DMD than the first light-shielding plate, has an opening that can shield and shape the light incident on the DMD from the light source, and the first light-shielding plate as viewed from the projection lens. An end substantially on the same straight line as the end, and a surface extending from the same end in the same direction as the surface extending from the first light shielding plate are formed, so that the off-light of the DMD does not enter the projection lens. A second black light-shielding plate that transmits the on-light of the DMD while shielding the light,
A projector comprising: A light source that generates light;
A projection lens for projecting incident light having a substantially circular entrance;
A DMD having a mirror surface composed of a plurality of micromirrors, each micromirror being driven in a time-sharing manner based on a video signal;
An optical engine for condensing the light from the light source on the mirror surface of the DMD;
A projector that generates a video based on an input video signal and projects and displays the video on a screen or the like.
A first light shielding plate that shields stray light from entering the projection lens;
A second light-shielding plate disposed closer to the DMD than the first light-shielding plate and shields the DMD off-light from entering the projection lens;
A projector comprising:   The projector according to claim 2, wherein the second light shielding plate has a black surface. The first light shielding plate is formed so as to have an end corresponding to a string with respect to the substantially circular shape of the incident port, and a surface extending from the same end to the inferior arc side with respect to the substantially circular shape,
The second light shielding plate has an end that is substantially collinear with the end of the first light shielding plate when viewed from the projection lens, and in the same direction as the surface from which the first light shielding plate extends. 4. The projector according to claim 2, wherein an extended surface is formed.

Images