JP2008134432A - Projector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a DLP type projector having a degree of freedom in an installation angle of a lamp. <P>SOLUTION: The projector includes the lamp 2, a collimator lens 11, a color wheel 12 separating light into R, G and B, a decentered lens 13, a rod type integrator 14, a doublet lens 15, a mirror 16, a relay lens 17, and an optical engine 5 having an image production element 3 modulating emission light from the relay lens 17 into image light and a projection lens 4 projecting the image light from the image production element 3. The projector inclines an optical axis of the emission light of the lamp 2 to an optical axis of the emission light of the decentered lens 13. The lamp 2 is arranged in a range of height of the optical engine 5 other than the lamp 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a DLP (Digital Light Processing) (registered trademark) projector.

  2. Description of the Related Art Conventionally, there has been known a projector that forms an image by an image generating element using light emitted from a lamp based on image data from a personal computer or a video camera, and projects the image on a screen or the like.

  As one type of projector of this type, a large number of mirror elements are regularly arranged vertically and horizontally, and an image is projected on a screen using a DMD (Digital Mirror Device) (registered trademark) that can individually control each mirror element. There is a DLP method.

  In this DLP projector, each mirror element of the DMD is driven individually in one of two directions, a direction in which illumination light is incident on a projection lens or a direction in which it is not incident, based on an image projected on a screen. As a result, the image is projected on the screen.

  An image by illumination light incident on the projection lens is projected on the screen. As is well known, in the DLP projector, the total number of mirror elements in the DMD is the number of pixels of the image projected on the screen. DMD mirror elements are very small. For example, in an area of 20 mm × 35 mm, 2.3 million elements can be arranged. Therefore, by using a DMD having a larger total number of mirror elements, an increase in the size of the optical system can be suppressed, and a high-definition image having a larger number of pixels can be projected on the screen.

  In a DLP projector, a plurality of optical components such as a color wheel, an integrator, a lens, a mirror, and a DMD are arranged in an optical path from a light source to a projection lens. Various types of optical components and their arrangements have been proposed depending on the purpose.

  For example, Patent Document 1 discloses a reflective display element, a light source system that projects illumination light toward a reflective display element from a direction inclined in one direction with respect to the front direction, and an output from the reflective display element. A projection system for projecting the image light onto the projection surface, and illumination light incident from a surface facing the light source system and the projection system, with respect to the front direction of the reflection display element. The light is corrected to parallel light along the tilted direction and is incident on the reflective display element, and the image light emitted from the reflective display element is incident on the projection system, and among the illumination light from the light source system, the light source system and the projection A projection display device is disclosed that includes a relay lens that emits light reflected from the surface on the surface facing the system in a direction other than the projection direction of image light by the projection system.

For example, Patent Document 2 discloses a light source, a color wheel that separates light emitted from the light source into R, G, and B light in a time-sharing manner, and condenses the light emitted from the color wheel to form parallel light. There is disclosed a DLP projector device that includes a condensing rod, the PS separation / combination element converts light emitted from the condensing rod, and causes the converted light to enter the DLP element.
JP 2005-99669 A JP-A-2005-128120

  Here, in a DLP projector, as in Patent Document 1 and Patent Document 2, the lamp to the mirror are generally arranged on a straight line. Therefore, there is no freedom in the installation angle of those components. Since the lamp occupies a large space in the optical system, the fact that there is no degree of freedom in the installation angle of the lamp means that the space around the lamp cannot be used effectively, and the height of the optical system depends on the size of the lamp. Get higher. Since the height of the optical system affects the height of the projector housing, there is a problem that the height of the product is increased.

  An object of the present invention is to provide a DLP projector having a degree of freedom in lamp installation angle.

In order to achieve the above object, the present invention provides a projector including an optical engine having a lamp, an integrator that emits incident light as planar light, and an image generation element that modulates incident light into image light.
A non-coaxial lens is provided on an optical path between the lamp and the integrator, and the optical axis of the emitted light of the lamp is inclined with respect to the optical axis of the emitted light of the non-coaxial lens. is there.

  In the projector described above, it is preferable that the lamp is arranged so that the height of the optical engine is reduced from the viewpoint of reducing the thickness of the product.

  In the projector described above, from the viewpoint of improving light efficiency, the non-coaxial lens may have a shape for condensing so that a focal point of light emitted from the non-coaxial lens overlaps an incident surface of the integrator. desirable.

  In the projector described above, from the viewpoint of reducing color unevenness, it is desirable to provide a color wheel that separates R, G, and B light in a time division manner on the optical path between the lamp and the non-coaxial lens. .

  In the projector described above, it is desirable to provide a collimator lens on the optical path between the lamp and the color wheel from the viewpoint of improving the light transmittance of the color wheel.

  7. The projector according to claim 6, wherein the incident surface of the non-coaxial lens is a flat surface from the viewpoint of maintaining parallel light that is easy to handle in the lens.

  In the projector described above, a digital mirror device in which a plurality of mirror elements are regularly arranged vertically and horizontally and each mirror element can be individually controlled can be adopted as the image generating element.

In the projector described above, the optical engine may further include a doublet lens that expands light emitted from the integrator, a mirror that reflects light emitted from the doublet lens, and a relay lens that expands light reflected from the mirror. A projection lens for projecting image light from the image generating element,
It is desirable that the lamp is disposed within a height range of the optical engine other than the lamp. This is to make the product thinner.

When the present invention is embodied,
A lamp,
A collimator lens that collimates the light emitted from the lamp;
A color wheel for separating light emitted from the collimator lens into R, G, and B light in a time-sharing manner;
A non-coaxial lens having a flat incident surface that refracts and collects light emitted from the color wheel; and
A rod-type integrator that emits the incident light from the non-coaxial lens as the incident surface and the incident light as a planar light, and
A doublet lens that expands the light emitted from the integrator;
A mirror that reflects light emitted from the doublet lens;
A relay lens that expands the reflected light from the mirror;
A plurality of mirror elements are regularly arranged vertically and horizontally, each mirror element can be individually controlled, and a digital mirror device that modulates light emitted from the relay lens into image light,
A projector comprising an optical engine having a projection lens for projecting image light from the digital mirror device,
Inclining the optical axis of the emitted light of the lamp with respect to the optical axis of the emitted light of the non-coaxial lens,
The lamp is configured to be disposed within a height range of the optical engine other than the lamp.

  According to the present invention, by using a non-coaxial lens, it is possible to give a degree of freedom to the installation angle of the lamp. Therefore, the space around the lamp can be used effectively, and the degree of freedom in design increases if the arrangement of other parts is taken into consideration. If the lamp is tilted upward and the lamp is placed within the height range of the optical engine other than the lamp, the size of the lamp does not affect the height of the optical engine, and the height of the product is kept low. be able to.

  FIG. 1 is a perspective view showing the appearance of the projector, and FIG. 2 is a partially cutaway plan view showing the configuration of the optical engine of the projector shown in FIG. The projector 1 is an apparatus that forms an image by an image generation element 3 using light emitted from a lamp 2 based on image data from a personal computer, a video camera, or the like, and projects the image onto a screen or the like through a projection lens 4. It is. In the figure, the alternate long and short dash line indicates the optical path.

  The projector 1 includes an optical engine 5 including a lamp 2 and an image projection optical system 10 including an image generation element 3 and a projection lens 4. The optical engine 5 is covered with a housing 20.

  The lamp 2 has an ellipsoidal reflector and a light source that emits light for image projection at a first focal point thereof. As the reflector, a parabolic mirror, an elliptical mirror, or the like can be used. For example, a light source that emits white light is used as the light source, and a halogen lamp, a metal halide lamp, a high-pressure mercury lamp, or the like can be used.

  The image projection optical system 10 forms an image using the light from the lamp 2 and projects the image. In addition to the image generation element 3 and the projection lens 4 described above, a collimator lens 11 and a color wheel 12 are used. A non-coaxial lens 13, an integrator 14, a doublet lens 15, a mirror 16, and a relay lens 17.

  The image generating element 3 is an element that forms an image by reflecting light, and thereby modulates incident light into image light. The image generating element 3 is provided on the circuit board 18. As the image generating element 3, it is desirable to use a DMD in which a large number of mirror elements are regularly arranged vertically and horizontally and each mirror element can be controlled individually.

  The projection lens 4 is a lens group that projects light reflected by the image generation element 3, that is, image light from the image generation element 3, and is disposed at a position facing an opening 21 provided in the housing 20. By using the lens group, the unclearness of the projected image due to the chromatic aberration of each color light of RGB is prevented.

  The collimator lens 11 converts the emitted light from the lamp 2 into parallel light, and is disposed near the second focal point of the lamp 2. By providing the collimator lens 11, parallel light is incident on the color wheel 12, so that light can be incident on the coating formed on the surface at a certain angle for the purpose of improving the transmittance of the color wheel 12, The transmittance is improved. The collimator lens 11 is not always necessary. In the case where the collimator lens 11 is not provided, it is desirable from the viewpoint of improving the light efficiency that the incident surface of the non-coaxial lens 13 is positioned near the second focal point of the lamp 2.

  The color wheel 12 has a substantially disk shape in which R, G, and B filters are arranged in the rotation direction thereof, and rotates about the rotation shaft 11a as an axis, and the light emitted from the collimator lens 11 is time-divisionally divided. Separate into R, G, and B light. The color wheel 12 may be provided immediately after the integrator 14.

  The non-coaxial lens 13 is a lens that refracts and emits light emitted from the color wheel 12. The non-coaxial lens 13 can play at least its role if provided on the optical path between the lamp 2 and the integrator 14, but is preferably provided immediately before the integrator 14. If the light emitted from the non-coaxial lens 13 is condensed, the light can be focused on the incident surface of the integrator 14 and the light efficiency is improved.

  Further, the incident surface of the non-coaxial lens 13 is preferably a flat surface. This is because the light collimated by the collimator lens 11 is incident on the non-coaxial lens 13, and by making the incident surface flat, refraction within the lens becomes parallel light and is easy to handle.

  The non-coaxial lens 13 may be integrated with the integrator 14. If it does so, the loss of the light which arises between the non-coaxial lens 13 and the integrator 14 will also be lose | eliminated, and manufacturing cost can also be reduced.

  As a specific shape of the non-coaxial lens 13, for example, a cylinder may be cut obliquely on a plane passing through only its side surface, and the bottom surface of the cylinder may be convex. According to this shape, the non-coaxial lens 13 having a flat incident surface that refracts and collects incident light is formed.

  The integrator 14 makes the incident light uniform and emits it as planar light. The integrator 14 uses the focal point of the emitted light from the non-coaxial lens 13 as the incident surface and emits the incident light as planar light. It is preferable that As the rod, a solid rod such as a glass rod or a hollow rod having an inner surface as a mirror surface can be adopted. According to the solid type rod, the reflectance in the inner surface reflection inside the rod can be almost 100%, so that the light efficiency is better than that of the hollow type.

  The doublet lens 15 is composed of two lenses that expand the light emitted from the integrator 14. Instead of the doublet lens 15, one lens or three or more lens groups may be used. The mirror 16 reflects the light emitted from the doublet lens 15 and makes the image projection optical system 10 compact by bending the optical path. The relay lens 17 is a lens that enlarges reflected light from the mirror 16.

  Here, since the planar light emitted from the integrator 14 is enlarged to cover the image generating element 3 using the doublet lens 15 and the relay lens 17, one of the lenses is eliminated and only the other lens is used. You may make it play the role.

  FIG. 3 is a front view of the optical engine 5 viewed in the direction of arrow A in FIG. The optical axis of the emitted light from the lamp 2 is inclined upward with respect to the optical axis of the emitted light from the non-coaxial lens 13. That is, the lamp 2 and the collimator lens 11 are disposed so as to be inclined upward. As shown in FIG. 3, since the mirror 16 is at the lowest position in the optical engine 5 and the projection lens 4 is at the highest position, the height H1 of the optical engine 5 is the lower end of the mirror 16. To the upper end of the projection lens 4.

  On the other hand, FIG. 4 is a front view of a comparative optical engine 5 ′ having no collimator lens 11 and non-coaxial lens 13, and is an example of a conventional product. 4, parts that are the same as those in FIG. 3 are given the same reference numerals, and detailed descriptions thereof are omitted. As shown in FIG. 4, each component is arranged so that the optical axis from the lamp 2 to the mirror 16 is a straight line. In the optical engine 5 ′, the lamp is at the lowest position and the projection lens 4 is at the highest position. Therefore, the height H 2 of the optical engine 5 ′ is from the lower end of the lamp 2 to the upper end of the projection lens 4. Up to.

  As apparent from a comparison between FIG. 3 and FIG. 4, the height H1 of the optical engine 5 of the present invention is lower than the height H2 of the optical engine 5 'of the comparative example. The difference H3 is the height from the lower end of the lamp 2 to the lower end of the mirror 16, as shown in FIG.

  In this manner, in the optical engines 5 and 5 ′, the lamp 2 occupies a large space. Therefore, the arrangement from the lamp 2 to the mirror 16 on a straight line as in the comparative example means that if the lamp 2 is large, it is optical. That is, the height of the engine 5 'is increased. As the height of the optical engine increases, the height of the projector housing 20 increases accordingly, that is, the height of the product increases accordingly.

  On the other hand, as in the optical engine 5 of the present invention, the lamp 2 can be disposed within the range of the height of the optical engine other than the lamp 2 if the lamp 2 is tilted upward and appropriately disposed. Therefore, the size of the lamp 2 does not affect the height of the optical engine 5 and does not affect the height of the housing 20, and the product height can be kept low.

  Further, the installation angle of the lamp 2 can be freely changed by a simple design change in which the direction of the non-coaxial lens 13 is changed. As a result, the space around the lamp 2 can be used effectively, and the degree of freedom in design can be increased by considering the arrangement of other components. For example, it is conceivable to place the lamp 2 in an empty space in the housing 20, and not only the lamp 2 is inclined upward as described above, but also the horizontal or downward inclination if space permits. Is also possible. If the lamp 2 is arranged so that the height of the optical engine 5 is lowered, it may be inclined not only upward but also obliquely upward.

  The present invention can be used for a DLP projector.

It is a perspective view which shows the external appearance of a projector. It is the partially broken top view which shows the structure of the optical engine of the projector of FIG. It is the front view which looked at the optical engine in the arrow A direction of FIG. It is a front view of the optical engine of the comparative example which does not have a collimator lens and a non-coaxial lens.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Projector 2 Lamp 3 Image generation element 4 Projection lens 5 Optical engine 11 Collimator lens 12 Color wheel 13 Non-coaxial lens 14 Integrator 15 Doublet lens 16 Mirror 17 Relay lens

Claims (9)

A lamp,
A collimator lens that collimates the light emitted from the lamp;
A color wheel for separating light emitted from the collimator lens into R, G, and B light in a time-sharing manner;
A non-coaxial lens having a flat incident surface that refracts and collects light emitted from the color wheel; and
A rod-type integrator that emits the incident light from the non-coaxial lens as the incident surface and the incident light as a planar light, and
A doublet lens that expands the light emitted from the integrator;
A mirror that reflects light emitted from the doublet lens;
A relay lens that expands the reflected light from the mirror;
A plurality of mirror elements are regularly arranged vertically and horizontally, each mirror element can be individually controlled, and a digital mirror device that modulates light emitted from the relay lens into image light,
A projector comprising an optical engine having a projection lens for projecting image light from the digital mirror device,
Inclining the optical axis of the emitted light of the lamp with respect to the optical axis of the emitted light of the non-coaxial lens,
The projector is characterized in that the lamp is disposed within a height range of the optical engine other than the lamp. In a projector including an optical engine having a lamp, an integrator that emits incident light as planar light, and an image generation element that modulates incident light into image light,
A projector comprising: a non-coaxial lens provided on an optical path between the lamp and the integrator, wherein the optical axis of the emitted light of the lamp is inclined with respect to the optical axis of the emitted light of the non-coaxial lens.   The projector according to claim 2, wherein the lamp is arranged so that a height of the optical engine is lowered.   The projector according to claim 2 or 3, wherein the non-coaxial lens has a shape for condensing so that a focal point of light emitted from the non-coaxial lens overlaps an incident surface of the integrator.   The color wheel which isolate | separates into the light of R, G, B by time division was provided on the optical path between the said lamp | ramp and the said non-coaxial lens, The Claim 2 characterized by the above-mentioned. projector.   6. The projector according to claim 5, wherein a collimator lens is provided on an optical path between the lamp and the color wheel.   The projector according to claim 6, wherein an incident surface of the non-coaxial lens is a flat surface.   The projector according to claim 2, wherein the image generation element is a digital mirror device in which a plurality of mirror elements are regularly arranged vertically and horizontally, and each mirror element can be individually controlled. The optical engine further includes a doublet lens that expands the output light from the integrator, a mirror that reflects the output light from the doublet lens, a relay lens that expands the reflected light from the mirror, and the image generation element. A projection lens that projects the image light of
The projector according to claim 2, wherein the lamp is disposed within a height range of the optical engine other than the lamp.

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