JP2010176055A - Projection display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent illuminance from being degraded by light absorption due to an adhesive member when a taper rod integrator is bonded to a holding member, in a projection display device using a plurality of light sources. <P>SOLUTION: The projection display device includes: the plurality of light sources; a display device part; a light-synthesizing part for synthesizing lights each output from the plurality of light source; a light-collecting and color-processing part for carrying out color processings by transmitting the lights output from the light-synthesizing part to the display device part; and a projection part for projecting a video image by using the light output from the display device. The light-synthesizing part includes the taper rod integrator 14, the four surfaces of which are tapered surfaces 145 and 146 and parallel surfaces 143 and 144, respectively, wherein the four surfaces connect an incident end surface 141 and an emission end surface 142, both having a square shape. The taper rod integrator 14 is bonded to a holding pedestal 43 at either the parallel surface 143 or the parallel surface 144. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a projection display device such as a projector provided with a light source as a light emitter and a taper rod integrator, and particularly relates to a technology for holding a taper rod integrator.

  Conventionally, as an apparatus for obtaining a large screen image, an image display device such as a DMD (Digital Micromirror Device) or a liquid crystal is used to modulate light from a light source lamp with a video signal to form an optical image and irradiate it. 2. Description of the Related Art Projection display devices such as projectors that perform enlarged projection on a screen using a projection lens are known.

In a two-lamp type, one-chip DLP (Digital Light Processing) (registered trademark) type projection display device, color sequential illumination using a color wheel is necessary. Therefore, it is necessary to suppress the time during which a plurality of colors are mixed and illuminated. On the other hand, a method of using a tapered rod integrator (hereinafter also simply referred to as “integrator”) has been proposed for the purpose of suppressing illuminance unevenness, color unevenness, and illumination loss. The taper rod integrator has a taper structure in the central axis direction (longitudinal direction) of the rod, and can narrow down the emitted light and reduce the illumination loss. As for the method of holding the taper rod integrator, a method of adhering to the holding member has been conventionally performed. In this case, since the refractive index of the integrator changes at the place where the adhesive member is adhered, the loss of total reflection increases and the illuminance of the projection display device decreases, so a method of providing a mirror reflective surface or a reflective layer at the adhesive location is available. (For example, refer to Patent Documents 1 and 2).
JP-A-11-326727 JP 2006-23473 A

  However, with the expansion of applications of projection display devices having a plurality of light sources, in recent years, demands for high brightness, high efficiency, power saving, and cost reduction are increasing. In order to cope with this, it is necessary to improve the utilization efficiency of the light emitted from the light source and to simplify the structure of the optical system. In particular, when an integrator is bonded and held to a holding member, the conventional method of providing a mirror reflecting surface or a reflecting layer at the bonding location complicates the holding structure of the integrator, so that improvement in quality, manufacturing and cost is an issue It has become.

  The present invention solves such problems and relates to holding an integrator in a projection display device using a plurality of light sources, and the illuminance of the light emitted from the integrator without providing a special additional structure in the bonding portion. An object of the present invention is to realize a projection display device that suppresses the deterioration of the image quality, and has high quality, low cost, and excellent productivity.

  In order to achieve the above object, a projection display apparatus according to the present invention includes a plurality of light sources, a display device, a light combining unit that combines output lights from the plurality of light sources, and a light output from the light combining unit to the display device. A projection display device comprising: a light condensing means; and a projection means for projecting an image on a screen by output light of the display device, wherein the light combining means has a four-sided tapered surface connecting the rectangular incident end face and the outgoing end face. And a taper rod integrator which is a parallel surface, and the taper rod integrator is bonded to the holding member on the parallel surface.

  With such a configuration, the taper rod integrator can be bonded to the holding member in a parallel plane. On the optical system, the parallel surface has a smaller number of reflections of light than the tapered surface. Therefore, by providing the bonding portion on the parallel surface, it is possible to reduce the amount of light flux absorbed at the bonding portion as compared to the tapered surface. Thereby, the fall of the illumination intensity resulting from adhesion | attachment to the holding member of a taper rod integrator can be suppressed. Moreover, when implementing this method, it is not necessary to take special measures in terms of structure. As a result, the holding structure of the taper rod integrator can be simplified, and a projection display device with high quality, low cost and excellent productivity can be realized.

  Further, in the projection display device of the present invention, in the parallel surface of the tapered rod integrator where a part of the region is a high temperature part higher than the softening point of the adhesive member during operation of the projection display device, the adhesion is made to the region excluding the high temperature part. Provide a place. With such a configuration, even if a part of the taper rod integrator reaches a temperature higher than the softening point of the adhesive member, the adhesive member does not soften, and the reliability of the adhesion can be improved. The allowable temperature concerned can be raised. As a result, the holding structure of the taper rod integrator can be simplified, and a projection display device with high quality, low cost and excellent productivity can be realized.

  In the projection display device of the present invention, a part of the area is projected onto the screen during operation of the projection display apparatus, and is adhered to the area excluding the reflection part on the parallel surface of the taper rod integrator. Provide a place. With such a configuration, even if there is an area where the adhesion point is reflected on the screen on the parallel surface of the taper rod integrator, the taper rod integrator can project a high-quality image with reduced decrease in illuminance without being affected by it. Can do. As a result, the holding structure of the taper rod integrator can be simplified, and a projection display device with high quality, low cost and excellent productivity can be realized.

  Further, the projection display device of the present invention includes two bonding portions on the parallel plane. With such a configuration, it is possible to increase the holding strength of the taper rod integrator, and it is possible to realize a projection display device with high durability, high quality, low cost, and excellent productivity with respect to impact or the like.

  In the projection display device of the present invention, the holding member has a heat dissipation structure. With such a configuration, the heat dissipation function of the taper rod integrator can be enhanced. Therefore, the installation temperature of the projection display device can be increased, and a projection display device that is versatile, high quality, low cost, and excellent in productivity can be realized.

  In the projection display device of the present invention, the holding member includes a pressing member that presses the taper rod integrator against the holding member. With such a configuration, the taper rod integrator can be pressed and fixed to the holding member by the pressing member. Therefore, it is possible to realize a projection display device having high mechanical strength, high quality, low cost and excellent productivity.

  According to the configuration of the present invention, in a projection display device having a structure in which a taper rod integrator is bonded and held to a holding member, the absorption of light at the bonded portion can be reduced without providing a special additional structure. Accordingly, it is possible to suppress a decrease in illuminance of the rod integrator due to light absorption by the adhesive member, and to realize a projection display device with high quality, low cost and excellent productivity.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

(Embodiment)
First, the outline of the optical system in the projection display apparatus according to the embodiment of the present invention will be briefly described with reference to FIG. FIG. 1 is a perspective view showing a schematic configuration of an optical system 2 of a projection display apparatus (hereinafter abbreviated as “present apparatus 1”) in an embodiment of the present invention.

  The optical system 2 in the apparatus 1 includes a light combining unit 30 as a light combining unit that combines output lights from the two lamps 11 and 12, and a display device unit 50 including an image display element such as a DMD (Digital Micromirror Device). A condensing / color processing unit 40 that performs condensing and color processing for propagating output light from the light combining unit 30 to the display device unit 50, and a projection unit as a projection unit that projects an image using output light from the display device unit 50 60.

  The optical system 2 includes a pair of two opposed lamps 11 and 12 sharing an optical axis, and the lamp 11 is provided with an arc tube 11b as a light source inside a concave mirror 11a having an elliptical cross section. ing. The same applies to the lamp 12. An ultra high pressure mercury lamp is used for the arc tube 11b, and a dielectric optical multilayer film for transmitting infrared light and reflecting visible light is formed on the inner surface of the glass-made material on the concave mirror 11a.

  Hereinafter, main configurations and functions of the optical system 2 will be described.

  An optical system 2 is an optical system of a two-lamp one-chip DLP projector.

  The white light from the arc tube 11b is collected by the concave mirror 11a, is then folded back by the combining mirror 13, and enters the tapered rod integrator 14 as convergent light that does not overlap each other. The light beam incident on the taper rod integrator 14 is split and superimposed into partial light beams by multiple reflection inside and is made uniform on the exit surface. The configuration and function of the taper rod integrator 14 will be described later.

  The color wheel 15 includes red, blue, and green filters. The light flux from the taper rod integrator 14 is separated into red, blue, and green color lights by passing through the color wheel 15 and becomes color sequential illumination in which the colors are sequentially switched. Each filter angle of the color wheel 15 is determined in accordance with the light emission characteristics of the lamps 11 and 12.

  The light beam that has passed through the color wheel 15 is incident on a TIR (Total Internal Reflection) prism 21 through a relay lens 16, reflection mirrors 17 and 18, and a field lens 19, and illuminates the DMD element 20. Only the light of the ON pixel modulated by the DMD element 20 enters the projection lens 22, and the image on the DMD element 20 is enlarged and projected on a screen (not shown).

  In the 1-chip DLP method, color sequential illumination by the color wheel 15 is necessary, and in order to increase the light utilization efficiency, the luminous flux is converged on the color wheel 15 to suppress the time for which a plurality of colors are mixedly illuminated. There is a need. As a measure against this, the apparatus 1 uses a tapered rod integrator 14 in the optical system 2 to reduce the diameter of the light beam on the color wheel 15 and suppress the mixing time.

  FIG. 2 is an explanatory diagram showing the function of the taper rod integrator 14 of the apparatus 1.

When two light beams are combined by a rod integrator without a taper, sufficient light flux does not enter within the taking-in angle of the optical system on the exit side of the rod. On the other hand, as shown in FIG. 2, when the taper rod integrator 14 having a taper structure is used only in the direction in which the combined angle θ _{1 of the} light emitted from the lamps 11 and 12 increases, the taper rod integrator 14 is tapered. By converting the angle of the illumination light by the surface, it is possible to take in the luminous flux of the combined angle θ ₁ of the two lamps from the incident end face 23 and to match the take-in angle θ ₂ at the exit end face 24. As a result, all the light beams emitted from the two lamps can be captured and advanced from the light collection / color processing unit 40 (FIG. 1) to the display device unit 50 (FIG. 1).

  3A and 3B are main layout diagrams relating to main mechanical components constituting the optical system 2 mounted on the apparatus 1, wherein FIG. 3A is a front view, FIG. 3B is a plan view, and FIG. 3C is a side view. . In the apparatus 1, a light synthesizing unit 30 and a projection unit 60, which are main mechanical components constituting the optical system 2, are arranged in a housing 70 as shown in FIG. 3.

  Next, a configuration relating to holding of the taper rod integrator 14, which is a configuration feature of the present invention, will be described with reference to FIGS. FIG. 4 is a partially enlarged perspective view of the photosynthesis unit 30 of the apparatus 1, and FIGS. 5 and 6 are an enlarged perspective view and a cross-sectional view showing a configuration related to holding the taper rod integrator 14 of the apparatus 1. 7 is a perspective view, a side view, and a cross-sectional view schematically showing a method of holding the taper rod integrator 14 of the apparatus 1.

  First, as shown in FIG. 4, an integrator unit 41 is disposed in the light combining unit 30 of the optical system 2. FIG. 5 is an enlarged perspective view showing a detailed configuration of the integrator unit 41, and FIG. 6 is a cross-sectional view taken along arrow A in FIG.

  As shown in FIGS. 5 and 6, the integrator unit 41 includes a unit substrate 42, a holding base 43, and a mounting plate 44. The holding table 43 is fixed to the unit substrate 42 by screws or the like (not shown), and the taper rod integrator 14 is fixed to the holding table 43 by screws 45 and 46 by a mounting plate 44. The mounting plate 44 has a spring property, and the taper rod integrator 14 is urged toward the holding base 43 by the projections 44a and 44b as pressing members. Further, an adhesive member (not shown) is inserted between the taper rod integrator 14 and the holding base 43 at two adhesion points P1 and P2 (the part indicated by arrow C in FIG. 6). Are mechanically pressed and bonded by an adhesive member and a pressing member 44. The holding table 43 includes a holding unit 47 and a heat radiating unit 48 and has a cooling function when the temperature of the taper rod integrator 14 rises.

  Next, a detailed holding method of the taper rod integrator 14 will be described with reference to FIG. FIG. 7A shows the shape of the taper rod integrator 14, and FIG. 7B is a schematic side view showing a method of holding the taper rod integrator 14 in the direction of arrow B in FIG. c) is a sectional view taken along line XX of FIG.

  As shown in FIG. 7A, the taper rod integrator 14 includes a rectangular incident end surface 141 and an output end surface 142, and four side surfaces 143, 144, 145, and 146 that couple the incident end surface 141 and the output end surface 142. Is done. Of these, the side surface 143 and the side surface 144 constitute parallel surfaces that face each other, and the side surface 145 and the side surface 146 constitute taper surfaces that face each other in a tapered shape. In other words, the taper rod integrator 14 includes two surfaces corresponding to the short side of the incident end surface 141 and the output end surface 142 among the four surfaces connecting the rectangular incident end surface 141 and the output end surface 142, and forms a long side. The two surfaces corresponding to the sides constitute parallel surfaces.

  Further, in the present apparatus 1, the taper rod integrator 14 and the holding base 43 are bonded to one surface, for example, the side surface 144, of the parallel surfaces 143 and 144 of the taper rod integrator 14. As shown in FIG. 7B and FIG. 7C, the taper rod integrator 14 is bonded by the bonding members 49a and 49b, and two bonding points with the holding base 43 are provided.

  Compared to the parallel surfaces 143 and 144, the tapered surfaces 145 and 146 can synthesize a wide range of light beams, so that the number of reflections of light within the taper rod integrator 14 is large. Therefore, when bonding is performed on the taper surfaces 145 and 146, the amount of light beam that is affected (absorbed) at the bonding portion where the refractive index changes and the reflection characteristic of the light beam changes is larger than that of the parallel surfaces 143 and 144. Become. On the other hand, the holding structure of the taper rod integrator 14 in the present apparatus 1 is bonded to the holding table 43 using an adhesive member at two locations on the long side surface, for example, the side surface 144 with a small number of reflections. Since the integrator 14 is held, it is possible to reduce the amount of absorption of the light beam at the bonded portion as compared with the tapered surfaces 145 and 146. Therefore, a decrease in illuminance due to adhesion of the taper rod integrator 14 to the holding table 43 can be suppressed. Moreover, when implementing this method, it is not necessary to take special measures in terms of structure. Thereby, the holding structure of the taper rod integrator 14 can be simplified, and a projection display device with high quality, low cost and excellent productivity can be realized.

  Further, as shown in FIG. 7 (b), in the present apparatus 1, a part of the region from the incident end surface 141 of the taper rod integrator 14 to the distance L1 during operation has a high temperature portion 14a higher than the softening point of the adhesive members 49a and 49b. Therefore, a bonding location P1 is also provided in which the bonding member 49a is disposed in a region excluding the high temperature portion 14a on the parallel surface of the taper rod integrator 14, for example, the side surface 144. Thereby, even if a part of the region of the taper rod integrator 14 becomes higher than the softening point of the adhesive member 49a, the adhesive member 49a is not softened, so that the reliability of the adhesion can be improved. In addition, the taper rod integrator 14 can be improved. It is possible to increase the allowable temperature related to the adhesion of. Thereby, the holding structure of the taper rod integrator 14 can be simplified, and a projection display device with high quality, low cost and excellent productivity can be realized.

  Further, in the present apparatus 1, if there is an adhesion portion in a part of the region extending from the emission end face 142 of the taper rod integrator 14 to the distance L2 during operation, that part is projected onto the screen to become the reflection part 14b. On the parallel surface 144 of the rod integrator 14, an adhesion point P2 is provided in a region excluding the reflection portion 14b. As a result, even if there is a reflection portion 14b of the adhesion portion on the parallel surface 144 of the taper rod integrator 14, it is possible to project a good quality image with reduced decrease in illuminance by the taper rod integrator 14 without being affected by it. it can. Thereby, the holding structure of the taper rod integrator 14 can be simplified, and a projection display device with high quality, low cost and excellent productivity can be realized.

  When the length of the taper rod integrator 14 is, for example, 74 mm, as an example of the high temperature portion 14 a and the reflection portion 14 b, for example, a region of about 5 mm from the incident end surface 141 becomes a high temperature portion and a region of about 15 mm from the emission end surface. It becomes the reflection part 14b.

  As described above, according to the apparatus 1 according to the present embodiment, since the taper rod integrator 14 is bonded to the holding base 43 on the parallel surface 144, the amount of light flux absorbed at the bonding points P1 and P2 is smaller than that of the taper surface. be able to. Thereby, the fall of the illumination intensity resulting from adhesion | attachment to the holding stand 43 of the taper rod integrator 14 can be suppressed. Moreover, when implementing this method, it is not necessary to take special measures in terms of structure. As a result, the holding structure of the taper rod integrator can be simplified, and a projection display device with high quality, low cost and excellent productivity can be realized.

  In the present embodiment, the taper rod integrator 14 and the holding base 43 are bonded to each other on one surface 144 of the parallel surface, but the present invention is not limited to this. It goes without saying that a method of bonding on the other surface 143 of the parallel surface or both surfaces 143 and 144 of the parallel surface is also possible.

  In this embodiment, a pair of two opposing light sources sharing the optical axis is used. However, two or more sets of two opposing light sources are provided, or the number of light sources is three or more. Needless to say, a projection display device can be configured based on the same concept.

  The present invention can be widely used in a projection display device including a taper rod integrator.

The perspective view which shows the outline of the principal part of the projection type display apparatus in embodiment of this invention. Explanatory drawing showing the function of the taper rod integrator Main layout of the optical system of the device Partially enlarged perspective view of the photosynthesis unit of the apparatus An enlarged perspective view showing a configuration related to holding of the taper rod integrator of the same device Sectional drawing which shows the structure regarding the holding | maintenance of the taper rod integrator of the apparatus A perspective view, a side view, and a sectional view schematically showing a method of holding the taper rod integrator of the same device

1 Projection display device (this device)
2 Two-lamp optical system (optical system)
DESCRIPTION OF SYMBOLS 11, 12 Lamp 11a Concave mirror 11b Arc tube 13 Composite mirror 14 Tapered rod integrator 14a High temperature part 14b Reflection part 15 Color wheel 16 Relay lens 17, 18 Reflection mirror 19 Field lens 20 DMD element 21 TIR prism 22 Projection lens 23, 141 Incident End face 24, 142 Emission end face 30 Photosynthesis part 40 Condensing / color processing part 41 Integrator unit 42 Unit substrate 43 Holding stand (holding member)
44 Mounting plate 44a, 44b Projection part 45, 46 Screw 47 Holding part 48 Heat radiation part 49a, 49b Adhesive member 50 Display device part 60 Projection part 70 Housing 70a, 70b, 70c Leg part 143, 144 Parallel surface (side surface)
145, 146 Tapered surface (side surface)
θ ₁ , θ ₂ Angle of light flux P1, P2

Claims (6)

A plurality of light sources, a display device, light combining means for combining the output lights of the plurality of light sources, a light collecting means for propagating the output light of the light combining means to the display device, and an image by the output light of the display device A projection display device including a projection unit configured to project on a screen, wherein the light combining unit includes a taper rod integrator in which four surfaces connecting a rectangular incident end surface and an output end surface are a tapered surface and a parallel surface; A projection display device, wherein a rod integrator is bonded to a holding member on the parallel plane. In the parallel surface of the taper rod integrator, in which a part of the region becomes a high temperature part higher than the softening point of the adhesive member during operation of the projection display device, a bonding portion is provided in a region excluding the high temperature part. The projection display device according to claim 1. In the parallel surface of the tapered rod integrator, which is projected onto a screen when a part of the projection type display device is operated, becomes a reflection part, and an adhesive spot is provided in an area excluding the reflection part. The projection display device according to claim 1 or 2. The projection display device according to any one of claims 1 to 3, wherein two of the bonding portions are provided on the parallel plane. The projection display device according to claim 1, wherein the holding member has a heat dissipation structure. The projection display device according to claim 1, wherein the holding member includes a pressing member that presses the taper rod integrator against the holding member.