JP2006010741A - Light source device including light emitting element and image display device using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light source device using a light emitting element, which is easily attached to a projector main body and which is made small in size and light in weight. <P>SOLUTION: The light source device 1 comprises a plurality of light emitting elements 20R, 20G and 20B, a cross dichroic prism 40 for outputting light beams from a plurality of light emitting elements in a 1st direction, a condenser lens 50 for condensing the output light from the prism 40, a light tunnel 60 for uniformizing the output light from the condenser lens 50, and a case main body 10 for holding a plurality of light emitting elements, the cross dichroic prism 40, the condenser lens 50 and the light tunnel 60. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a projection-type image display device used in a projection-type high-definition television (HDTV) system, a video projector, and the like, and in particular, a plurality of light-emitting elements capable of emitting red, green, and blue in the image display device. The present invention relates to a light source device or a light source module thereof.

  Projectors represented by projection-type image display devices use spatial modulation devices such as liquid crystal and DMD (Digital Micro-mirror Device), which modulates the light from the light source and displays a color image on the screen. ing. The present applicant has previously disclosed an image display device disclosed in Patent Document 1. FIG. 8 shows this image display apparatus. As shown in the figure, the light from the white light source 51 is reflected by an elliptical mirror 52 and the reflected light is incident on a rotatable color wheel 53. The color wheel 53 is a transmissive filter in which R (red), G (green), and B (blue) color filters are arranged in the circumferential direction. The light transmitted through the color wheel is reflected by the condenser lens 1 and the spherical mirror 2 serving as a folding mirror, and enters the DMD 56 at a high angle. Of the light incident on the DMD, the light reflected by the on-state pixels is displayed on the screen 58 via the projection lens 57. R, G, and B light are sequentially transmitted from the color wheel 53, and the DMD pixel is driven at a timing synchronized therewith, so that a time-division color image is displayed.

  Here, as described in Non-Patent Document 1, the DMD 56 includes two-dimensionally arranged pixels composed of minute mirrors, and each pixel has an electrostatic field generated by a memory element disposed immediately below the mirror. This is a reflective display element that controls the tilt of a micromirror by action and changes the reflection angle of reflected light to create an on / off state. When the pixel is off, the reflected light from the micro mirror of the pixel does not enter the projection lens. When the pixel is on, the reflected light from the micro mirror of the pixel enters the projection lens and the image is displayed on the screen. Optical components are arranged to form. The tilt angle of each pixel when the micromirror is on is determined to be about 10 to 12 degrees with respect to the incident surface of the DMD ray.

  The projector uses a halogen lamp, a xenon lamp, or the like as a light source. However, these lamps have a problem that power consumption is large and heat generation is large. In order to avoid this, Patent Document 2 discloses a technique of using light emitting diode (LED) arrays 1R, 1G, and 1B as light sources as shown in FIG. The illumination optical system includes red, green, and blue LEDs, first fly-eye lenses 2R, 2G, and 2B adjacent to each LED, second fly-eye lenses 3R, 3G, and 3B spaced from the first fly-eye lenses 2R, 2G, and 2B, 2 includes a cross dichroic prism 4 that receives light from the fly-eye lens and emits combined illumination light of red, green, and blue from the exit surface. Further, Patent Document 3 discloses a similar technique using a light emitting element array 2 of red, blue, and green LEDs or laser elements as a light source, as shown in FIG.

JP 2002-268010 A JP 2003-186110 A JP-A-10-333599 “Optics”, Vol. 25, no. 6, p313-314, 1996

  However, the conventional projector has the following problems. As disclosed in Patent Document 1, light emitted from a light source is configured to enter a color wheel. For example, when outputting red light, other colors are reflected by the color wheel. Therefore, it cannot be said that the light from the light source is effectively used. One solution to this problem is to use light emitting elements of three colors, red, green and blue, as shown in Patent Document 2 and Patent Document 3, and switch these light emitting elements to light. is there. As a result, it is possible to eliminate waste of light use efficiency due to the use of the color wheel. However, the light sources disclosed in Patent Documents 2 and 3 are not yet commercialized, and the ease of handling in manufacturing as an actual product and the cost are not considered.

  In particular, in the illumination optical system shown in Patent Document 2 (see FIG. 9), the light emitted from the cross dichroic prism 4 passes through the illumination lens 5, the reflecting mirror 6, the illumination lens 7, and the DMD illumination prism 8. Therefore, it is difficult to reduce the size and weight of the light source unit.

  In the illumination optical system shown in Patent Document 3 (see FIG. 10), the light emitted from the light emitting element array 2 passes through the shaping optical system 3 including the microlens array 30 and the reduction optical system 4 including the dichroic mirror 4. In order to illuminate the light modulation device 5 via the light source device, it is necessary to design the light emission direction from the light emitting element and the light incidence direction to the modulation device to be at different angles. Difficult to make.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a light source device using a light emitting element that solves the above-described conventional problems and can be easily attached to a projector main body and can be reduced in size and weight.

  The light source device according to the present invention includes a plurality of light emitting elements, a first optical component that outputs light rays from the plurality of light emitting elements in a first direction, and a first light that condenses output light from the first optical component. The second optical component, a third optical component that uniformizes the output light from the second optical component, a plurality of light emitting elements, and a case body that holds the first, second, and third optical components. . Preferably, a thin light source device is provided by arranging a plurality of light emitting elements and first to third optical components in the case body.

  Preferably, the electrode terminals of the plurality of light emitting elements are provided on the same surface of the case body. A plurality of light emitting elements are provided on the same surface side, and the light source device further includes a mirror component that guides light from the plurality of light emitting elements to the first optical component.

  Further, the plurality of light emitting elements each emit light having different wavelengths in the first direction, and the first optical component includes a cross dichroic prism that outputs the light emitted from the plurality of light emitting elements in the first direction. It may be a thing.

  The third optical component includes, for example, a light tunnel or an optical integrator. For example, the light tunnel may have an integrated configuration including a reflective surface formed on the inner surface of a space formed in the case body.

  Preferably, the light source device further includes a drive control device that controls drive timings of the plurality of light emitting elements, and the plurality of light emitting elements emit red, green, and blue light in response to the drive timing of the drive control device. To do. As the light emitting element, a semiconductor light emitting diode or a semiconductor laser diode can be used. In addition, the light emitting elements may be arranged in an array to improve the light intensity.

  An image display apparatus according to the present invention includes a light source device having the above characteristics, a spatial modulation unit that modulates light from the light source device, and a projection unit that projects the spatially modulated light. As the spatial modulation means, for example, a DMD or a liquid crystal element can be used.

  According to the light source device of the present invention, since the plurality of light emitting elements and the first to third optical components are all housed and modularized in the case body, the handling is easy and the light source device can be downsized. Weight reduction can be achieved. Furthermore, it is possible to contribute to the reduction in size and weight of an image display device such as a projector incorporating such a light source device.

  The image display apparatus according to the present invention is implemented in a projection type projector using DMD. Details will be described below with reference to the drawings.

  1 is a perspective view of a light source device according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view seen from above when cut along the XX plane of FIG. 1, and FIG. It is sectional drawing seen from the side when cut | disconnecting at a YY surface. In these drawings, the light source device 1 includes a rectangular case body 10, a plurality of light emitting elements 20R, 20G, and 20B held in the case body 10, a pair of mirrors 30 and 32, and a cross dichroic prism 40. The condenser lens 50 and the light tunnel 60 are provided.

  FIG. 4 shows the light emitting element 20R as a representative, but the other light emitting elements 20G and 20B have the same configuration as the light emitting element 20R. The light emitting element 20 </ b> R includes an LED element 24 </ b> R on the substrate 22, and the LED element 24 </ b> R is sealed with a transparent sealing member 26. Furthermore, an electrode terminal 28R is attached to the back side of the substrate 22, and the electrode terminal 28R is electrically connected to the LED element 24R by a bonding wire or the like (not shown). The LED element 24 </ b> R emits light in a red wavelength band in a direction substantially perpendicular to the substrate 22. The LED element 24G of the light emitting element 20G emits light in the green wavelength band, and the LED element 24B of the light emitting element 20B emits light in the blue wavelength band. Preferably, each LED element can be an edge-emitting diode or a surface-emitting diode.

  Three openings 14R, 14G, and 14B are formed in the side surface 12 of the case body 10 at substantially equal intervals. Reflecting surfaces 16R, 16G, and 16B having curved curved surfaces are formed in the case body 10, and these reflecting surfaces are connected to the openings 14R, 14G, and 14B. The planar shape when the reflecting surfaces 16R, 16G, and 16B are cut in the X direction is a circle, and the planar shape when cut in the Y direction is an ellipse. The reflective surfaces 16R, 16G, and 16B may have an integrated structure in which a reflective film such as a metal is vapor-deposited or welded on the inner wall surface of the case body, or a structure in which individual reflectors are attached to the inner wall surface. Also good.

  The light emitting elements 20R, 20B, and 20B are inserted into the case body 10 from the openings 14R, 14G, and 14B in the Y1 direction. Then, the electrode terminal 28 is fixed in a state protruding from the one side surface 12. LED elements 24R, 24G, and 24B are positioned in the vicinity of the focal positions of the reflecting surfaces 16R, 16G, and 16B, and the light emitted from the LED elements 24R, 24B, and 24B at a certain spread angle in the Y1 direction is reflected on the reflecting surfaces 16R, Reflected so as to converge in the optical axis direction by 16G and 16B.

  Further, the case body 10 is formed with a space 18 communicating with the reflecting surfaces 16R, 16G, and 16B. In the space 18, a mirror 30 is attached at a position facing the reflecting surface 16R. The mirror 30 is arranged so as to be orthogonal to the X and Y directions and inclined 45 degrees clockwise from the Y1 direction. Preferably, the mirror 30 has the same size as the opening of the reflecting surface 16R, reflects all of the light reflected from the reflecting surface 16R in the X2 direction without leaking, and enters the incident surface of the cross dichroic prism 40. 42 is incident. The mirror 30 may be an integrated structure in which a reflective film such as a metal is vapor-deposited or adhered to the inner wall surface of the case body 10, or an individual mirror may be attached to the inner wall surface.

  Similarly, in the space 18, a mirror 32 inclined by 45 degrees is attached at a position facing the reflecting surface 16B. The mirror 32 reflects the light from the reflecting surface 16B substantially at right angles to the X1 direction, and causes almost all of the reflected light to enter the incident surface 44 of the dichroic prism.

  In the space 18, a cross dichroic prism 40 is provided in a direction that coincides with the optical axis of the reflecting surface 16G. The reflected light from the reflecting surface 16G is directly incident on the incident surface 46 of the cross dichroic prism 40. The cross dichroic prism 40 outputs the light of the light emitting element 20R incident from the incident surface 42 in the Y1 direction from the emission surface 48, and emits the light of the light emitting element 20B incident from the incident surface 44 in the Y1 direction from the emission surface 48. Then, the light of the light emitting element 20G incident from the incident surface 46 is output from the emission surface 48 in the Y1 direction.

  A condenser lens 50 is disposed at a position close to the emission surface 48. The space 18 includes a rectangular space 18a extending from the emission surface 48 in the Y1 direction by a certain distance, and the condenser lens 50 is mounted in the space 18a. Preferably, the optical axis of the condenser lens 50 substantially coincides with the optical axis of the reflecting surface 16G. The condenser lens 50 condenses the light from the emission surface 48 of the cross dichroic prism 40 and makes it incident on the incident surface of the light tunnel 60 arranged in the Y1 direction.

  The incident surface 62 of the light tunnel 60 is located in the rectangular space 18a. The optical axis of the light tunnel 60 is substantially equal to the optical axis of the condenser lens 50, and the focal position of the condenser lens 50 is adjusted in the vicinity of the incident surface 62. As shown in FIG. 5, the light tunnel 60 has an internal space 66 surrounded by four mirrors 64 on its four sides, and repeatedly reflects the light incident from the incident surface 62 in the internal space 66. A substantially uniform beam is output from the exit surface 68. Since the shape of the light beam depends on the cross-sectional shape of the light tunnel 60, it is desirable that the aspect ratio of the cross-sectional shape of the light tunnel 60 corresponds to the illumination area of the DMD micromirror.

  As described above, in the present embodiment, the light emitting elements 20R, 20G, and 20B, the mirrors 30 and 32, the cross dichroic prism 40, the condenser lens 50, and the light tunnel 60 are accommodated in the case body 10 and handled as a module. And the manufacturing efficiency of the projector is improved. Furthermore, as shown in FIG. 2, since these light emitting elements and optical members are juxtaposed in the thin case body 10, the light source device 1 can be made thinner and smaller.

  Next, FIG. 6 shows a configuration of a light source device according to the second embodiment of the present invention. The light source device of the second embodiment is obtained by improving the configuration of the light tunnel, and the other configuration is the same as that of the first embodiment. As shown in FIG. 6, the case body 10 is formed with a rectangular space 70 for a light tunnel. One end portion 72 of the space 70 communicates with the rectangular space 18a, and this becomes the incident surface of the light tunnel. The other end portion 74 extends to the other side surface 12a of the case main body, and that becomes an emission surface. A reflective surface such as metal is formed on the inner wall surface forming the space 70, and the space 70 functions as a light tunnel integrated with the case body.

  According to the second embodiment, the number of parts can be reduced as compared with the first embodiment, and a low-cost light source device can be provided.

  In the light source device of the above embodiment, a semiconductor light emitting diode is used as a light emitting element, but a semiconductor laser diode can also be used in addition to this. Furthermore, although the light emitting elements 20R, 20G, and 20B are single elements, the present invention is not limited to this, and the light intensity may be increased by arranging the light emitting elements in a two-dimensional array. In this case, it is desirable that the center of the two-dimensional array is located on the focal position of the reflecting surface.

  Further, in the above embodiment, the light tunnel 60 is used to make the light intensity uniform. However, the light tunnel 60 may be made uniform using an optical integrator made of a glass member such as a rectangular parallelepiped.

  Next, FIG. 7 shows a configuration of a projector to which the light source device of this embodiment is applied. The projector includes a light source device 1 according to the first embodiment, two reflection mirrors 100 and 110 that irradiate the DMD with light from the light source device 1, a DMD 120 in which a plurality of micromirrors are arranged in a two-dimensional array, The projection lens 130 that projects the reflected light from the DMD 120, the light emitting element driving device 140 that drives the light source device 1, and the DMD control device 150 that controls the light emitting element driving device 140.

  The light emitting element driving device 140 outputs drive pulse signals R-EN, G-EN, and B-EN for driving the light emitting elements 20R, 20G, and 20B to the light source device 1. The drive pulse signal is output at different timings in a time division manner, and the light emitting elements 20R, 20G, and 20B emit red (R), green (G), and blue (B) light in response to the pulse period. The R, G, and B lights illuminate the DMD 120 in a time-sharing manner through the reflecting mirrors 100 and 1110, and the reflected light of the micromirrors that are in the ON state is incident on the projection lens 130, and a color image is displayed on the screen. Is displayed.

  The DMD control device 150 controls the timing of the driving signal of the light emitting element driving device 140 and provides image signal data to the DMD 120. The DMD 120 drives the minute mirror based on the image signal data in synchronization with the timing at which the R, G, and B light is emitted from the light source device 1.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the gist of the present invention described in the claims. Modifications and changes are possible. In the above embodiment, the DMD is used as the spatial modulation element. However, the present invention is not limited to this, and a liquid crystal or the like may be used.

  The image display apparatus according to the present invention can be used in a projection type projector that projects and displays television images, video images, and the like. For example, the image display device can be used in a front projection type projector, a rear projection type projector, and the like.

It is a perspective view of the light source device which concerns on the 1st Example of this invention. It is the YY sectional view taken on the line of FIG. It is the XX sectional view taken on the line of FIG. It is a figure which shows the structure of a light emitting element. It is a figure which shows the cross section of a light tunnel. It is a longitudinal cross-sectional view which shows the structure of the light source device which concerns on the 2nd Example of this invention. It is a block diagram when the light source device of a 1st Example is applied to a projector. It is a figure which shows the structure of the conventional projector. It is a figure which shows the structure of the conventional projector. It is a figure which shows the structure of the conventional projector.

Explanation of symbols

1: Light source device 10: Case main body 12: Side surface 14R, 14G, 14B: Opening 16R, 16G, 16B: Reflecting surface 18: Space 18a: Rectangular space 20R, 20G, 20B: Light emitting element 24R, 24G, 24B: LED element 30 32: Mirror 40 Cross dichroic prism 42, 44, 46: Entrance surface 48: Output surface 50: Condenser lens 60, 70: Light tunnel

Claims (9)

A plurality of light emitting elements;
A first optical component that outputs light rays from a plurality of light emitting elements in a first direction;
A second optical component for condensing output light from the first optical component;
A third optical component for equalizing output light from the second optical component;
A light source device comprising a plurality of light emitting elements and a case main body for holding first, second and third optical components. The light source device according to claim 1, wherein electrode terminals of the plurality of light emitting elements are provided on the same surface of the case main body. The light source device according to claim 1, wherein the plurality of light emitting elements are provided on the same surface side, and the light source device further includes a mirror component that guides light from the plurality of light emitting elements to the first optical component. The plurality of light emitting elements each emit light of different wavelengths in a first direction, and the first optical component includes a cross dichroic prism that outputs light emitted from the plurality of light emitting elements in the first direction. The light source device according to claim 1. The light source device according to claim 1, wherein the third optical component includes a light tunnel or an optical integrator. The light source device according to claim 1, wherein the light tunnel includes a reflective surface formed on an inner surface of a space formed in the case main body. The light source device further includes a drive control device that controls drive timing of the plurality of light emitting elements, and the plurality of light emitting elements emit red, green, and blue light in response to the drive timing of the drive control device. Item 7. The light source device according to any one of Items 1 to 6. The light source device according to claim 1, wherein the plurality of light emitting elements, the first optical component, the second optical component, and the third optical component are juxtaposed in the case main body. A light source device according to any one of claims 1 to 8,
Spatial modulation means for modulating light from the light source device;
An image display device comprising: a projecting unit that projects spatially modulated light.

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