JP2023022126A - Illumination device and projection-type video display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination device capable of freely changing a light flux aspect ratio without being limited to arrangement intervals of light source units and without increasing the number of optical members and complexifying a retention mechanism.

SOLUTION: The illumination device comprises: a light source unit including a plurality of two-dimensionally arranged semiconductor laser elements; a collimator lens arranged on the front surface of the light source unit and converting a travelling direction of light flux of emission light from each semiconductor laser into substantially parallel light; and at least one optical element arranged on the front surface of the collimator lens, and changing the travelling direction of the substantially parallel light only in a predetermined uni-axial direction. The optical element includes a first surface that has light permeability and is perpendicular to the substantially parallel light, and a second surface inclined to the first surface. When the substantially parallel light enters the first surface, the optical element refracts the light on the second surface, thereby changing the travelling direction of the substantially parallel light only in the uni-axial direction to thus emit light flux inclined to the substantially parallel light.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to an illumination device using a plurality of semiconductor lasers as an illumination light source and a projection image display device using the illumination device.

2. Description of the Related Art In recent years, technology has been developed to use a semiconductor laser instead of a conventional discharge lamp using mercury as an illumination light source for an illumination device and a projection type image device.

A collimating lens placed in front of the semiconductor laser light can shape the light into a substantially parallel beam, so it is possible to collect light more efficiently than conventional discharge lamps. Since the light output of each unit cannot be said to be sufficiently high, in order to increase the light output of the illumination device and the projection type image display device, a light source unit in which a plurality of semiconductor lasers and collimator lenses are arranged is configured to increase the light output. be done.

A reduction optical system is placed behind the light source unit, and by reducing the light beam of nearly parallel light emitted from the light source unit into spot light, for example, it is possible to excite the phosphor and focus the light on the rod end surface of the integrator optical system. becomes.

A light source unit generally consists of a plurality of individual semiconductor lasers arranged regularly, and it is difficult to arrange them closely due to the physical size restrictions of the semiconductor laser package and the collimating lens placed in front. As a result, the ray bundle of the light source unit becomes a ray bundle with a gap.

In addition, the aspect ratio of the arrangement of the light source units (corresponding to the aspect ratio of the screen with multiple spotlights) may not be the desired size due to product restrictions on the arrangement of the light source units, such as thinning of the device and light intensity balance. There is In this case, the size of the lens system of the reduction optical system in the subsequent stage is constrained by the size of the large aspect ratio, resulting in an increase in the size of the equipment.

In addition, when used in a projection-type image display device, if the ray bundle is reduced by the reduction optical system in the latter stage while the aspect ratio is large, the outermost edge of the ray bundle is reduced when condensed on the integrator optical system. Since the ray angle is determined by the image height incident on the lens, if the aspect ratio of the ray emitted from the illumination device differs for each color, the angle of the ray entering or exiting the integrator optical system, that is, the angle of the ray The F value will be different. As a result, when all the light is used as projection light, the optical system becomes large.

Conversely, if the F-number of the optical system is set small so as to limit light rays with different F-numbers, the light rays are blocked in the middle of the optical system. Not only does this decrease the light output reaching the screen, but also the vertical and horizontal F-numbers for each color are different. The color of the light will also change, making it difficult to obtain a stable light output.

In order to improve this, a configuration for correcting the entire optical system, such as tapering the rod in the integrator optical system and correcting the vertical and horizontal ray angles by the cylindrical lens, is required.

In Patent Document 1, a plurality of optical elements having reflecting surfaces with different directions are arranged on the front surface of the light source unit, part of the light beam emitted from the light source unit is reflected, and the semiconductor lasers in the same axial direction in the light source unit are arranged. A light source device has been devised in which the light beam of the light source unit is reduced in one direction by reflecting the light again between the array pitches.

Furthermore, in Patent Document 2, a plurality of optical elements having reflecting surfaces with different directions are arranged in all optical axis rows other than the central axis, and in addition, the length of the optical elements is changed for each row, thereby producing a semiconductor laser. A light source device has been devised in which the light beam of the light source unit is reduced in one direction regardless of the arrangement interval of the light source unit.

JP 2016-186585 A JP 2016-186909 A

However, in the technique described in Patent Document 1, a plurality of optical elements are used to reflect light between the arrangement pitches of the semiconductor lasers in the light source unit. Therefore, the reduction interval is limited by the arrangement interval of the semiconductor lasers, and there is a problem that separate optical correction is required to arrange the semiconductor lasers with the optimum aspect ratio.

In addition, in the technique described in Patent Document 2, in order to overcome the problem of Patent Document 1, a plurality of optical elements having different lengths are used so that the arrangement pitch of the semiconductor lasers in the light source unit is not limited to the arrangement interval of the semiconductor lasers. However, there is a problem that an optical element having a different size is required for each row, which causes an increase in the number of optical members and complication of the holding mechanism.

In addition, in the techniques described in Patent Documents 1 and 2, the reflecting surfaces of the two optical elements are configured so that the light beams incident on the optical elements and the light beams emitted from the optical elements are directed in the same direction. There is a problem that the arrangement is limited so that the light beam is perpendicular to the surface of the light source unit.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems, and to provide a lighting system and a projector capable of freely changing the aspect ratio without being restricted by the arrangement interval of the semiconductor lasers without increasing the number of optical members and complicating the holding mechanism. To provide a type image display device.

A lighting device according to the present invention includes:
a light source unit including a plurality of semiconductor laser elements arranged in a two-dimensional direction;
a collimating lens arranged in front of the light source unit and configured to convert the traveling direction of the light beam emitted from each of the semiconductor lasers into substantially parallel light;
at least one optical element arranged in front of the collimating lens and configured to change the traveling direction of the substantially parallel light only in a predetermined one-axis direction;
A lighting device comprising
The optical element has optical transparency and has a first surface perpendicular to the substantially parallel light and a second surface inclined with respect to the first surface,
When the substantially parallel light is incident on the first surface, the optical element refracts the substantially parallel light at the second surface, thereby changing the traveling direction of the substantially parallel light only in the uniaxial direction, emitting an oblique luminous flux that is inclined with respect to the substantially parallel light, thereby obtaining a predetermined aspect ratio from the aspect ratio of the screen of the plurality of spot lights from the light source unit in a cross section at a predetermined position in the traveling direction of the oblique luminous flux; It is characterized by being configured to be changed to

Therefore, according to the illumination device of the present invention, the aspect ratio can be freely changed without being restricted by the arrangement interval of the semiconductor lasers without increasing the number of optical members and complicating the holding mechanism. etc. can be provided.

1 is a schematic plan view showing a configuration example of a projection display apparatus 1 according to Embodiment 1. FIG. FIG. 2 is a schematic plan view showing an internal configuration example of the illumination device 101 of FIG. 1; FIG. 3 is a schematic plan view showing a configuration example and an optical path of a green light source unit 201G in FIG. 2; FIG. 3 is a schematic side view showing a configuration example and an optical path of a green light source section 201G in FIG. 2; FIG. 3B is a front view showing a screen composed of a plurality of spotlights in the cross section L250 of FIGS. 3A and 3B; FIG. 3B is a front view showing a screen composed of a plurality of spotlights in the section L251 of FIGS. 3A and 3B; 3 is a schematic plan view showing a configuration example and an optical path of a red light source unit 201R of FIG. 2; FIG. 3 is a schematic side view showing a configuration example and an optical path of a red light source section 201R in FIG. 2; FIG. FIG. 5 is a front view showing a screen composed of a plurality of spotlights in cross section L260 of FIGS. 4A and 4B; FIG. 4C is a front view showing a screen composed of a plurality of spotlights in the section L261 of FIGS. 4A and 4B; FIG. 5 is a front view showing a screen composed of a plurality of spotlights in cross section L262 of FIGS. 4A and 4B; 3 is a schematic plan view showing an arrangement application example 1 of the optical element 204R of FIG. 2. FIG. FIG. 3 is a schematic plan view showing an arrangement application example 2 of the optical element 204R of FIG. 2; FIG. 11 is a schematic plan view showing an arrangement application example 3 of the optical element 204R of FIG. 2; FIG. 11 is a schematic plan view showing an arrangement application example 4 of the optical element 204R of FIG. 2; FIG. 11 is a schematic plan view showing a configuration example of a projection display apparatus 2 according to Embodiment 2; FIG. 7 is a schematic front view showing a configuration example of a phosphor wheel 305 of FIG. 6; FIG. 7 is a schematic side view showing a configuration example of a phosphor wheel 305 of FIG. 6; FIG. 7 is a schematic plan view showing an example of the internal configuration of the illumination device 301 of FIG. 6; FIG. 9 is a front view showing a configuration example of a partially reflecting mirror 501 of FIG. 8; FIG. 9 is a front view showing a configuration example of a partially reflecting mirror 502 of FIG. 8; FIG. 7 is a schematic front view showing an arrangement example of respective spot lights B1, B2, and B3 emitted from the illumination device 301 of FIG. 6 and proceeding to a phosphor excitation afocal optical system 310; FIG. 7 is a schematic front view showing spot light B1 emitted from the illumination device 301 of FIG. 6 and proceeding to the blue afocal optical system 320;

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid unnecessary verbosity in the following description and to facilitate understanding by those skilled in the art.

It should be noted that the accompanying drawings and the following description are provided for a thorough understanding of the present disclosure by those skilled in the art and are not intended to limit the claimed subject matter.

(Embodiment 1)
Embodiment 1 will be described below with reference to FIGS. 1 to 5. FIG. As a specific embodiment of the projection display apparatus according to the present disclosure, a projection display apparatus having a digital micromirror device (hereinafter referred to as "DMD") that performs optical deflection control will be described below.

[1-1. composition]
FIG. 1 is a schematic plan view showing a configuration example of a projection display apparatus 1 according to Embodiment 1. FIG.

In FIG. 1, the projection-type image display apparatus 1 includes an illumination device 101, an afocal optical system 110, a reflecting mirror 102, a diffuser wheel 103, a condensing optical system 104, a rod integrator 105, a relay optical system 120, and an internal total reflection prism. (hereinafter referred to as “TIR prism”) 130 , an optical deflection control section 106 and a projection optical system 140 . Here, the afocal optical system 110 includes, for example, a single-convex lens 111 and a double-concave lens 112 . The relay optical system 120 includes, for example, single-convex lenses 121 and 123 and a bi-convex lens 122 . The TIR prism 130 is configured with prisms 131 and 132, for example.

A beam of parallel laser light output from the lighting device 101 passes through the afocal optical system 110 , is reflected by the reflecting mirror 102 , and then passes through the diffuser wheel 103 . The passing laser light is condensed by the condensing optical system 104 after its coherence is reduced by the diffuser wheel 103 . The condensed laser light enters a rod integrator 105 which is a reduction optical system, is converted into a uniform light quantity distribution, and is guided to the light deflection control section 106 via the relay optical system 120 and the TIR prism 130 . Image light is generated by deflecting light according to the light modulation signal by the DMD of the light deflection control unit 106 . The generated image light is projected onto the screen 400 via the projection optical system 140, and an image corresponding to the image light is displayed.

[1-1-1. Configuration of lighting device]
FIG. 2 is a schematic plan view showing an internal configuration example of the illumination device 101 of FIG.

In FIG. 2, the illumination device 101 is configured with three-color light source units 201B, 201G, and 201R and color synthesizing mirrors 210 and 211 .

The red light source unit 201R includes a red light source unit 202R having a plurality of red light sources, a plurality of collimating lenses 203R provided corresponding to each red light source, and a plurality of optical elements provided corresponding to each red light source, for example. 204 R and a triangular prism 205 . The green light source unit 201G includes a green light source unit 202G having a plurality of green light sources, a plurality of collimating lenses 203G provided corresponding to each green light source, and a plurality of optical elements provided corresponding to each green light source, for example. 204G. The blue light source section 201B includes a blue light source unit 202B having a plurality of blue light sources and a plurality of collimating lenses 203B provided corresponding to each blue light source. The optical elements 204G and 204R for each color are composed of triangular prisms, for example.

The light source units 202B, 202G, and 202R are light sources of blue, green, and red, respectively. 2 to 5 are used. The reason why the number of light source units is different for each luminescent color is to balance the light output and luminosity of each color. In the configuration example of FIG. 2, the blue light source unit 202B is composed of two light source blocks BB, the green light source unit 202G is composed of three light source blocks BG, and the red light source unit 202R is composed of five light source blocks BR. It is As a result, the aspect ratios of the light source units 202B, 202G, and 202R for each color (corresponding to the aspect ratio of the screen by a plurality of spotlights from the light sources, hereinafter referred to as "aspect ratio") are different from each other as follows.
(1) The blue light source unit 202B is composed of light source blocks BB arranged in a 4×4 array, and the aspect ratio thereof is 1:1.
(2) The green light source unit 202G is composed of light source blocks BG arranged in a 4×6 array, and its aspect ratio is 2:3.
(3) The red light source unit 202R is composed of light source blocks BR arranged in a 4×10 array and has an aspect ratio of 2:5.

3A is a schematic plan view showing a configuration example and optical paths of the green light source unit 201G in FIG. 2, and FIG. 3B is a schematic side view showing a configuration example and optical paths of the green light source unit 201G in FIG. 3C is a front view showing a screen composed of a plurality of spotlights on the cross section L250 of FIGS. 3A and 3B, and FIG. 3D is a screen composed of a plurality of spotlights on the cross section L251 of FIGS. 3A and 3B. It is a front view showing. In FIG. 3A, the direction of laser light emission is the X-axis direction, the direction perpendicular to the X-axis direction on the plane of FIG. 3A is the Y-axis direction, and the direction perpendicular to the XY plane is the Z-axis direction.

In FIGS. 3A and 3B, the light emitted from each light source of the green light source unit 202G is shaped by the collimator lens 203G into substantially parallel light substantially parallel to the X-axis direction, and then sent to the plurality of optical elements 204G. Incident. Here, each optical element 204G has an incident plane 204P that is perpendicular to the substantially parallel light and is inclined at a predetermined inclination angle θ with respect to the incident plane 204P (that is, 204Q is a light-transmitting optical element composed of an output plane 204Q inclined at an angle θ. ing. For example, the material of the optical element 204G used in this configuration example is borosilicate glass (BK7), the inclination angle θ is 37 degrees, and the refraction angle θd of incident substantially flat light is about 29 degrees. .

The light emitted from the collimating lens 203G is incident through the incident plane 204P of the optical element 204G, and then refracted by an angle θd by the inclined outgoing plane 204Q. Only one axis direction is changed, and is emitted from the emission plane 204Q of the optical element 204G at an angle of, for example, about 29 degrees with respect to the light rays (X-axis direction) emitted from the collimator lens 203G via the optical element 204G. As shown in FIG. 3A, each of the plurality of optical elements 204G is displaced from the optical element 204G with respect to the traveling direction (X-axis direction) of substantially parallel light from the collimator lens 203G. It is possible to change the compression rate of the emitted light flux. In the configuration example of FIG. 3A, the aspect ratio of the screen by the plurality of spot lights from the blue light source unit 201B is 1:1 at the cross section L251, and the phases of the plurality of lights emitted from the collimating lenses 203G are at the cross section L251. The positions of the plurality of optical elements 204G are adjusted in the X-axis direction so that they are in phase with each other. In the example using the configuration example of FIG. 3A, since the distance between the plurality of light sources of the light source unit 201G is 11 mm, the adjacent optical elements 204G are arranged to be shifted by about 4.7 mm in the X-axis direction.

As a result, as shown in FIG. 3C, the aspect ratio of the screen composed of the plurality of spot lights from the green light source unit 202G is 2:3 in the cross section L250 after being emitted from each collimating lens 203G. On the other hand, in the cross section L251 after passing through the plurality of optical elements 204G, as shown in FIG. 3D, the plurality of A screen composed of spotlights is shaped. The aspect ratio can be arbitrarily changed by changing the inclination angle θ (angle with respect to the X-axis direction) and/or the spacing of each optical element 204G. Although the spot light emitted from each collimating lens 203G is actually an elliptical light, it is illustrated as a circular light so that the shape change state during shaping can be easily understood.

Similar to the green light source unit 202G described above, the red light source unit 202R also performs aspect conversion using a plurality of optical elements 204R. This will be explained below.

4A is a schematic plan view showing a configuration example and optical paths of the red light source unit 201R in FIG. 2, and FIG. 4B is a schematic side view showing a configuration example and optical paths of the red light source unit 201R in FIG. 4C is a front view showing a screen composed of a plurality of spotlights on the cross section L260 of FIGS. 4A and 4B, and FIG. 4D is a screen composed of a plurality of spotlights on the cross section L261 of FIGS. 4A and 4B. FIG. 4E is a front view showing a screen, and FIG. 4E is a front view showing a screen composed of a plurality of spotlights in cross section L262 of FIGS. 4A and 4B.

In FIGS. 4A and 4B, the light output from the red light source unit 202R is shaped into substantially parallel light by the collimator lens 203R, and then enters through the incident plane 204P of the plurality of optical elements 204R. Here, each optical element 204R is an optical element having a light transmission property composed of an incident plane 204P perpendicular to the substantially parallel light and an output plane 204Q inclined with respect to the incident plane 204P, The tilt angle θ of the tilted output plane 204Q is set to an angle at which incident light is not totally reflected within the optical element 204R. The light incident on the plurality of optical elements 204R is refracted by the inclined emission plane 204Q of the optical element 204R, and the traveling direction of the light from the red light source unit 202R is changed, for example, only in one axial direction on the XY plane, and the optical element 204R It is emitted from the emission plane 204Q. In the configuration example of FIG. 4A, the material of the optical element 204R is borosilicate glass (BK7) like the optical element 204G, the tilt angle θ is 37 degrees, and the light refraction angle θd is about 29 degrees. . Also, the light source interval of the light source unit 201R is 11 mm as in the light source unit 201G, and the adjacent optical elements 204R are arranged with a shift of about 2.0 mm.

The aspect ratio of the screen composed of a plurality of spotlights output from the red light source unit 202R is 2:5, which is much larger than the aspect ratio (1:1) of the blue light source unit 201B. It is difficult to compress to an aspect ratio of 1:1 with only a more emitted luminous flux. The light emitted from the optical element 204R re-enters the triangular prism 205 arranged after that, and is refracted to correct the traveling direction of the light to be substantially parallel to the substantially parallel light from the collimating lens 203R, and to convert the light flux. It can be compressed to an aspect ratio of 1:1 and emitted from the red light source section 201R. In this configuration example, the triangular prism 205 is also made of borosilicate glass (BK7) like the optical element 204R, and has an inclination angle θ of 37 degrees and a light refraction angle θd of about 29 degrees.

As a result, as shown in FIG. 4C, the aspect ratio of the red light source unit 202R is 2:5 in the cross section L260 after the light is emitted from the collimating lens 203R. On the other hand, on the section L261 after passing through the optical element 204R, as shown in FIG. 4D, the aspect ratio similar to that of the blue light source unit 202B is changed to approximately 2:3.5. After that, on the cross section L262 after passing through the triangular prism 205, as shown in FIG. 4E, the aspect ratio is changed to 1:1 similar to that of the blue light source unit 202B and the green light source unit 202G.

As shown in FIG. 2, the light beams emitted from the light source units 201B, 201G, and 201R are synthesized by color synthesizing mirrors 210 and 211 having different transmission and reflection characteristics for each wavelength. It is emitted from the illumination device 101 . Specifically, the color combining mirror 210 is formed with a dichroic film that transmits the red wavelength band and reflects the green wavelength band, and the color combining mirror 211 transmits the red and green wavelength bands and reflects the blue wavelength band. A dichroic film is formed to reflect the

[1-1-2. Configuration of Projection Display Unit]
As shown in FIG. 1, the parallel light flux output from the illumination device 101 enters the afocal optical system 110 and is shaped into converged parallel light. In the afocal optical system 110, the single-convex lens 111 is a condenser lens that collects parallel light from the illumination device 101, and the biconcave lens 112 is a lens that converts the light from the lens 111 into parallel light. A light beam emitted from the afocal optical system 110 is reflected by the reflecting mirror 102 and then passes through the diffuser wheel 103 . The diffusion plate wheel 103 has a disk-shaped rotating body with a diffusion plate attached thereto. When the wheel is rotated by a drive motor, the heat generation of the diffusion plate is suppressed and the coherence of the light source of the illumination device 101 is maintained. And it becomes possible to disturb the polarization characteristic state, and suppress the speckle of the image projected on the screen 400 . The light emitted from the diffuser wheel 103 is condensed by the condensing optical system 104 and then incident on the end face of the rod integrator 105 .

The light incident on the rod integrator 105 repeats total internal reflection within the rod integrator 105, and is output from the opposite end surface as surface emission with a uniform luminance distribution. The rod integrator 105 is a solid rod made of transparent material such as glass. The rod integrator 105 internally reflects incident light multiple times to generate light with a uniform light intensity distribution. It should be noted that the rod integrator 105 may be a hollow rod whose inner wall is composed of a mirror surface. The luminous flux emitted from the illumination device 101 is changed to have an aspect ratio of 1:1. are equal.

A light beam emitted from the rod integrator 105 enters a relay optical system 120, passes through a single-convex lens 121, a double-convex lens 122, and a single-convex lens 123, which are relay lenses, so as to obtain a desired paraxial magnification and angular magnification (F value). After being reshaped, it enters TIR prism 130 . The TIR prism 130 is composed of two prisms 131 and 132, and a thin air layer (not shown) is formed between adjacent surfaces of the prisms 131 and 132. FIG. The air layer totally reflects light incident at an angle equal to or greater than the critical angle. The light incident on the TIR prism 130 from the lens relay lens optical system 120 is totally reflected by this air layer, and substantially forms an image on the light deflection control section 106 .

The optical deflection control unit 106 has a DMD, and modulates the DMD based on various control signals such as video signals to generate video light with different light intensities in a time division manner. Specifically, the DMD has a plurality of movable micromirrors. Each micromirror basically corresponds to one pixel. The DMD changes the angle of each micromirror based on the modulation signal from the optical deflection control section, thereby switching whether to direct the reflected light to the projection optical system 140 or not. After the light reflected by the DMD passes through both prisms 132 and 131 of the TIR prism 130, the light to be projected as an image (DMD-ON light) is incident on the projection optical system 140 and then emitted to the screen 400. Other light (DMD-OFF light) does not enter the projection optical system 140 and is not displayed as an image.

Here, the light beam incident on the optical deflection control unit 106 is changed to a desired F value both in the vertical direction and the horizontal direction due to the effect of changing the aspect ratio when emitted from the illumination device 101, and the DMD-ON light is It is possible to efficiently pass through the diaphragm in the projection optical system 140 and project onto the screen 400 .

Further, when the projection optical system 140 has a zoom function, the F-number of the projection optical system may change during the zoom operation. At that time, if the F-number of each color is not the same, the ratio of the colors passing through the diaphragm in the projection optical system 140 changes, and this may be perceived as a chromaticity change on the screen 400. However, the present technology is used. If it is, it is possible to suppress the occurrence of this chromaticity change.

The operations of the light source units 201B, 201G, and 201R in the illumination device 101 are time-divided, and the image projected by the light deflection control unit 106 with colored lights of red, green, and blue regions having different light intensities is projected onto the screen 400. It arrives and is perceived as a full-color image. At this time, if the time-division cycle is long, the human eye may perceive color flicker. is driven at triple speed (180 fps) of video information, color flickering can be suppressed.

[1-2. effects, etc.]
As described above, the projection display apparatus 1 including the illumination device 101 according to this embodiment includes the light source units 201B, 201G, and 201R in which a plurality of semiconductor laser elements are arranged two-dimensionally, and the light source units 201B, 201B, and 201R. a collimating lens 203 arranged in front of 201G and 201R for converting the traveling direction of the light beam emitted from the semiconductor laser into substantially parallel light; and one or more optical elements 204 having optical transparency. In addition, after the parallel light is in the above plane of the optical element 204, the throwing image display device 1 is refracted by the inclined fire plane of the light academic element 204, and is arranged in the two -dimensional direction 202B, The traveling direction of the substantially parallel light from 202G and 202R is changed only in one axial direction, and in a state in which the traveling direction is obliquely changed, an oblique light beam of substantially parallel light is emitted, and the light source unit 202B is emitted in the traveling direction of the oblique light beam. , 202G, and 202R are configured to emit converted light beams having a uniform aspect ratio. Therefore, it is possible to increase the luminous efficiency and eliminate the chromaticity change even when the F-number of the projection optical system changes.

In addition, since the vertical and horizontal aspect ratios can be freely set by adjusting the inclination angle θ of the optical elements 204B, 204G, and 204R and the method of arranging the optical elements 204B, 204G, and 204R, the degree of freedom in arranging the semiconductor lasers is increased, and the illuminating device 101 and the projection display device 1 are thin. It is possible to suppress the increase in the number of optical members and the complication of the holding mechanism in designing the optical system.

In this embodiment, the optical elements 204G and 204R are composed of different triangular prisms for each row, but the present invention is not limited to this. .

5A is a schematic plan view showing an arrangement application example 1 of the optical element 204R of FIG. 2, and FIG. 5B is a schematic plan view showing an arrangement application example 2 of the optical element 204R of FIG. 5C is a schematic plan view showing an arrangement application example 3 of the optical element 204R of FIG. 2, and FIG. 5D is a schematic plan view showing an arrangement application example 4 of the optical element 204R of FIG.

In FIG. 5A, the tilted output planes 204Q of the plurality of optical elements 204R are arranged on a straight line. Further, in the case of such a configuration, as shown in FIG. 5B, triangular prisms extending over a plurality of rows such as the plurality of optical elements 204RA may be arranged. In this case, it is possible to reduce the number of parts and simplify assembly. When the optical element 204R is arranged so that the output plane 204Q of the optical element 204R is positioned on a straight line as shown in FIG. 5A, the shift amount Δd of each pair of adjacent optical elements 204R is , and the luminous flux width W after passing through the optical element 204R becomes narrower.

As shown in FIG. 5C, when the shift amount .DELTA.d is zero, the luminous flux width W widens compared to FIGS. 5A and 5B. Furthermore, as shown in FIG. 5D, by making the shift amount Δd negative and shifting in the −X-axis direction, contrary to FIG. 5C, the beam width W can be further widened. Thus, by changing the shift amount Δd or the tilt angle θ of the plurality of optical elements 204R, which are triangular prisms, the aspect ratio can be changed arbitrarily.

According to the present embodiment, the illumination device constituted by the light source units 202B, 202G, and 202R and the projection type image display device using the same can be provided without increasing the number of optical members and complicating the holding mechanism. The aspect ratio can be freely changed without being restricted by the arrangement interval of the .

Further, according to the present embodiment, by guiding the light beam with the changed aspect ratio to the reduction optical system, the light beam angle of the aspect ratio can be freely changed at the exit portion of the reduction optical system, thereby obtaining the F of the projection optical system. It is possible to provide a projection-type image display device or the like that does not change chromaticity even when the value changes.

Furthermore, according to this embodiment, by selectively changing the direction of only a portion of the light beams emitted from the light source units 202B, 202G, and 202R and guiding the light beams to different optical systems, the size of the device can be reduced and the cooling mechanism can be simplified. can be made.

As described above, the embodiments have been described as examples of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can also be applied to embodiments in which modifications, replacements, additions, omissions, etc. are made as appropriate. Further, it is also possible to combine the constituent elements described in the above embodiment to form a new embodiment.

(Embodiment 2)
In the first embodiment, the light source units 201B, 201G, and 201R are configured independently for each color in the illumination device 101, but the light source units of the light source units may be shared for different colors. The projection display apparatus 2 according to the embodiment configured as described above will be described below.

FIG. 6 is a schematic plan view showing a configuration example of the projection display device 2 according to the second embodiment.

In FIG. 6, the projection display apparatus 2 according to the second embodiment mainly differs from the projection display apparatus 1 according to the first embodiment in the following points.
(1) DMDs 106R, 106G, and 106B driven by the optical deflection control unit 106 and used for the three primary colors of red, green, and blue, respectively.
(2) In the first embodiment, light sources with different emission colors from the light source units 201B, 201G, and 201R are used. On the other hand, in Embodiment 2, the illumination device 301 includes three light source units 202BA, 202BB, and 202BC for only blue light, and green and red light emit yellow fluorescent light obtained by exciting phosphors with a blue light source. take advantage of

[1-1. composition]
6, the projection display apparatus 2 includes an illumination device 301, a phosphor excitation afocal optical system 310, a blue afocal optical system 320, reflection mirrors 302, 303, 304, a diffuser wheel 103, and a dichroic mirror 306. , phosphor condensing lens 330 , phosphor wheel 305 , condensing optical system 104 , rod integrator 105 , relay optical system 120 , TIR prism 130 , color prism 340 , light deflection controller 106 , and projection optical system 140 . Configured. Here, the phosphor excitation afocal optical system 310 includes, for example, a single-convex lens 311 and a double-concave lens 312 . The blue afocal optical system 320 includes, for example, a single convex lens 321 and a biconcave lens 322 . Phosphor condenser lens 330 includes, for example, single-convex lenses 331 and 332 . The relay optical system 120 includes, for example, a single-convex lens 121, a double-convex lens 122, and a single-convex lens 123.

In FIG. 6, the illumination device 301 outputs two blue parallel light beams. One of the blue parallel light beams output from the illumination device 301 is incident on the blue afocal optical system 320 , reflected by the reflecting mirrors 302 and 303 , and then passes through the diffuser wheel 103 . Here, after the coherence of the laser light is reduced by the diffusion plate wheel 103 , the laser light passes through the dichroic mirror 306 , is condensed by the condensing optical system 104 , and enters the rod integrator 105 . The dichroic mirror 306 is configured to transmit blue-range light and reflect yellow-range light (green-range light and red-range light).

The other blue parallel light beam output from the illumination device 301 is incident on the phosphor excitation afocal optical system 310, passes through the dichroic mirror 306, passes through the phosphor condenser lens 330, and reaches the phosphor. A focused spot is formed near the wheel 305 . Here, the phosphor condensing lens 330 is composed of, for example, single-convex lenses 331 and 332, which are condenser lenses, and efficiently collects parallel light from the afocal optical system 310 for phosphor excitation to the vicinity of the phosphor wheel 305. In addition, the high NA fluorescence emitted from the phosphor wheel is also configured to be corrected to parallel light.

7A is a schematic front view showing a configuration example of the phosphor wheel 305 of FIG. 6, and FIG. 7B is a schematic side view showing a configuration example of the phosphor wheel 305 of FIG.

7A and 7B, the phosphor wheel 305 comprises an aluminum substrate 361 and a drive motor 360 at its center, and constitutes a circular substrate whose rotation is controllable about a central axis 360X. A reflective film (not shown) and a phosphor layer 362 are further formed on the surface of the aluminum substrate 361 . A reflective film is a metal layer or dielectric film that reflects visible light. In the phosphor layer 362, a Ce-activated YAG-based yellow phosphor that emits yellow light containing green and red wavelength components when excited by blue light is formed. A representative chemical structure of the crystal matrix of this phosphor is Y ₃ Al ₅ O ₁₂ . The phosphor layer 362 is formed in an annular shape.

The phosphor layer 362 excited by the spot light emits yellow light containing green light and red light. The phosphor wheel 305 is made of an aluminum substrate 361, and is rotated about a central axis 360X to suppress the temperature rise of the phosphor layer 362 due to blue excitation light, thereby stably maintaining the fluorescence conversion efficiency. . The light incident on the phosphor layer 362 fluoresces green component and red component color light, and is emitted from the phosphor wheel 305 . Also, the light emitted to the reflective film side is reflected by the reflective film and emitted from the phosphor wheel 305 . The green component and red component color light emitted from the phosphor layer 362 is emitted as natural light with a random polarization state, condensed again by the single-convex lenses 332 and 331, which are condenser lenses, and converted into substantially parallel light. After that, it enters the dichroic mirror 306 . Dichroic mirror 306 is configured to reflect yellow light, which is reflected and travels toward condensing optics 104 .

The blue light not excited by the phosphor layer 362 is reflected by the reflective film, converted again into substantially parallel light by the single-convex lenses 332 and 331 as condenser lenses, and then enters the dichroic mirror 306 . Since the dichroic mirror 306 transmits the light in the blue region, the light returns toward the phosphor excitation afocal optical system 310 and does not travel toward the condensing optical system 104 .

In this way, the green and red colored light emitted from the phosphor layer 362 and the blue colored light that has passed through the blue afocal optical system 320 are emitted from the dichroic mirror 306 toward the condensing optical system 104 side. be done. These colored lights are color-combined and visually recognized as white light. The light transmitted through the dichroic mirror 306 is incident on the condensing optical system 104 and condensed on the rod integrator 105 .

The rod integrator 105 is a solid rod made of transparent material such as glass. The rod integrator 105 internally reflects incident light multiple times to generate light with a uniform light intensity distribution. It should be noted that the rod integrator 105 may be a hollow rod whose inner wall is composed of a mirror surface.

Relay lenses 121 , 122 , and 123 substantially image the light emitted from rod integrator 105 onto DMD 106 . Light emitted from the rod integrator 105 passes through the relay lenses 121 and 122 , passes through the relay lens 123 after being deflected by the reflecting mirror 304 , and enters the TIR prism 130 . The TIR prism 130 is composed of two prisms 131 and 132, and a thin air layer (not shown) is formed between adjacent surfaces of the prisms 131 and 132 to each other. The air layer totally reflects light incident at an angle equal to or greater than the critical angle. The light incident on the TIR prism 132 from the relay lens 123 is totally reflected by this air layer and enters the color prism 340 .

The color prism 340 is composed of three prisms 340G, 340B, and 340R, each of which has a blue-reflecting dichroic mirror (not shown) and a red-reflecting dichroic mirror (not shown) formed on the adjacent surface. By each dichroic mirror, the color prism 340B receives only the blue color gamut light, the color prism 340R receives only the red color gamut light, and the color prism 340G receives only the green color gamut light. The light is dispersed and approximately images are formed on the DMDs 106B, 106R, and 106G of the optical deflection control unit 106 corresponding to the respective colors.

The optical deflection control unit 106 has three DMDs 106B, 106R and 106G, and modulates the DMDs 106B, 106R and 106G according to various control signals such as video signals to generate video light with different light intensities. Specifically, each DMD 106B, 106R, 106G has a plurality of movable micromirrors. Each micromirror basically corresponds to one pixel. The DMDs 106B, 106R, and 106G change the tilt angle of each micromirror based on the modulation signal, thereby switching whether to direct the reflected light to the projection optical system 140 or not. Light reflected by DMDs 106B, 106R, and 106G passes through both color prism 340 and TIR prism . Of the transmitted light, light projected as an image (DMD-ON light) enters the projection optical system 140 and is projected as an image on the screen 400 to display the image. Other light (DMD-OFF light) does not enter the projection optical system 140 and is not displayed on the screen 400 .

FIG. 8 is a schematic plan view showing an internal configuration example of the illumination device 301 of FIG.

In FIG. 8, the illumination device 301 is configured with blue-only light source units 202BA, 202BB, 202BC, a plurality of collimator lenses 203B, a plurality of optical elements 204B, and partial reflection mirrors 501, 502. In FIG. Here, each of the blue-only light source units 202BA, 202BB, and 202BC includes three light source blocks BB in which blue semiconductor lasers are arranged in a two-dimensional 4×2 array in the vertical and horizontal directions. As a result, the total light sources of the light source units 202BA, 202BB, and 202BC are configured in a 4×6 array with an aspect ratio of 2:3.

Of the spot light B1 output from the blue-only light source unit 202BA, the spot light B1 that passes through the plurality of optical elements 204B is incident on the single convex lens 321, while the spot light B1 that does not pass through the plurality of optical elements 204B is partially reflected by the mirror. After being reflected by 502 , it enters a single-convex lens 311 in an afocal optical system 310 for phosphor excitation. Also, the spot light B2 output from the blue-only light source unit 202BB is reflected by the partial reflection mirror 501, passes through the partial reflection mirror 502, and enters the single-convex lens 311 of the afocal optical system 310 for phosphor excitation. Further, the spot light B3 output from the blue-only light source unit 202BC passes through the partially reflecting mirrors 501 and 502, and then enters the single-convex lens 311 of the afocal optical system 310 for phosphor excitation. A configuration example for realizing the above operations will be described below.

9A is a front view showing a configuration example of the partially reflecting mirror 501 in FIG. 8, and FIG. 9B is a front view showing a configuration example of the partially reflecting mirror 502 in FIG.

9A and 9B, partially reflective mirrors 501 and 502 are constructed by forming a dielectric reflective film (not shown) on the surface of a glass plate. In the partially reflecting mirror 501, as shown in FIG. 9A, a plurality of rectangular slits 501s (passing through in the thickness direction) that pass only a predetermined spot light B3 and have a vertical longitudinal direction are arranged in the semiconductor element. formed at intervals. Further, in the partially reflecting mirror 502, as shown in FIG. 9B, a plurality of rectangular slits 501s (passing through in the thickness direction) having a horizontal longitudinal direction are formed to allow passage of only predetermined spot light beams B2 and B3. It is formed at the arrangement intervals of the semiconductor elements.

In FIG. 8, the blue-only light source units 202BB and 202BC are arranged such that the light beam traveling position is laterally shifted by half the distance between the semiconductor elements. Therefore, the spot light B3 emitted from the light source unit 202BC passes through the plurality of slits 501s of the partially reflecting mirror 501 and advances to the partially reflecting mirror 502. FIG. On the other hand, the spot light B2 emitted from the light source unit 202BB is reflected by the dielectric reflection film of the partial reflection mirror 501 and travels to the partial reflection mirror 502 .

The blue-only light source unit 202BA is arranged such that the positions along which light rays from the blue-only light source units 202BB and 202BC travel are shifted in the vertical direction by half the distance between the semiconductor elements. Therefore, the spot light B3 that has passed through the partially reflecting mirror 501 passes through the plurality of slits 502s of the partially reflecting mirror 502 and advances to the single convex lens 311 of the afocal optical system 310 for phosphor excitation. Further, of the spot light B1 output from the blue-only light source unit 202BA, after passing through the collimating lens 203B, the spot light B1 of the portion where the optical element 204B is not attached to the front proceeds without changing the direction of travel. After reaching the reflecting mirror 502 , the light is reflected by the dielectric reflecting film in the partially reflecting mirror 502 and proceeds to the single convex lens 311 of the afocal optical system 310 for phosphor excitation. On the other hand, the spot light B1 of the portion where the optical element 204 is attached to the front surface of the blue-only light source unit 202BA is refracted within the optical element 204, does not reach the partial reflection mirror 502, and does not reach the blue afocal optical system 320. Proceed to the single-convex lens 321 .

10A is a schematic front view showing an arrangement example of the spot lights B1, B2, and B3 emitted from the illumination device 301 of FIG. 6 and proceeding to the phosphor excitation afocal optical system 310, and FIG. 3 is a schematic front view showing spot light B1 emitted from the device 301 and proceeding to the blue afocal optical system 320. FIG.

As shown in FIG. 10A, the light spots B1, B2 and B3 that have passed through or are reflected by the partially reflecting mirrors 501 and 502 are aligned at half the spacing of the semiconductor elements. The aspect ratio of this light source arrangement is 2:3, which is the same as the aspect ratio of the blue-only light source units 202BA, 202BB, and 202BC in FIG. After being incident on the phosphor excitation afocal optical system 310 , the light beam passes through the dichroic mirror 306 , passes through the phosphor condenser lens 330 , and forms a focused spot light in the vicinity of the phosphor wheel 305 . The condensed spot light excites the phosphor layer 362 to emit yellow light containing green and red color components. The phosphor spotlight is a very small spotlight with a diameter of about 2 mm, and spreads even when the phosphor emits light. Even if it is 2:3, the aspect ratio of the screen due to the spot light reflected by the phosphor layer 362 is corrected to approximately 1:1, so efficiency is not greatly affected.

On the other hand, FIG. 10B shows the arrangement of the spot light B1 that passes through the three optical elements 204, does not reach the partially reflecting mirror 502, and proceeds to the afocal optical system 320 for blue. Since the three optical elements 204 are attached to the light sources on one side of the three light source blocks BB of the blue-only light source unit 202BA, the aspect of the screen by the spot light B1 traveling from the blue-only light source unit 202BA to the three optical elements 204 Although the ratio is 2:3, when it is refracted by the plurality of optical elements 204 as shown in the first embodiment, it is compressed in the horizontal direction and deformed from the screen 401 to the screen 402, and the blue afocal optical system The output light whose aspect ratio is changed to 1:1 is incident on 320 .

The luminous flux incident on the afocal optical system 320 for blue passes through the diffuser wheel 103 after being reflected by the intermediate reflection mirrors 302 and 303 . After the coherence of the laser light is reduced by the diffuser wheel 103 , the transmitted light is transmitted through the dichroic mirror 306 , condensed by the condensing optical system 104 , and incident on the rod integrator 105 . In this way, since the blue-range light is directly incident on the rod integrator 105, by setting the aspect ratio to 1:1, it becomes possible to match the aspect ratio of the reflected light from the phosphor layer 362 to 1:1. Efficiency reduction in the optical system 140 does not occur. In addition, since all of the blue, green, and red regions of light are present, it is possible to project a good image without losing the white balance even if the F-number of the projection lens changes.

[1-2. effects, etc.]
As described above, according to the illumination device 301 and the projection display device 2 according to this embodiment, the plurality of optical elements 204 are used to separate the light fluxes output from the blue light source units 202BA, 202BB, and 202BC. Moreover, by changing the aspect ratio, it is possible to simplify the optical system and downsize the projection display apparatus 2 . In addition, since the blue-only light source units 202BA, 202BB, and 202BC can have an integral structure, the cooling mechanism of the light source units 202BA, 202BB, and 202BC can be streamlined to reduce costs.

As described above, the embodiment has been described as an illustration of the technology in the present disclosure. To that end, the accompanying drawings and detailed description have been provided. Therefore, among the components described in the attached drawings and detailed description, there are not only components essential for solving the problem, but also components not essential for solving the problem in order to illustrate the above technology. can also be included. Therefore, it should not be determined that those non-essential components are essential just because they are described in the attached drawings and detailed description.

In addition, the above-described embodiments are intended to illustrate the technology of the present disclosure, and various modifications, replacements, additions, omissions, etc. can be made within the scope of the claims or equivalents thereof.

The present disclosure makes it possible to freely change the luminous flux aspect ratio without being restricted by the arrangement interval of the light source units, without increasing the number of optical members and complicating the holding mechanism in a lighting device and a projection type image display device. Therefore, it is possible to realize an illumination device and a projection type image display device.

1, 2 ... projection type image display device,
101... Lighting device,
102... Reflecting mirror,
103... diffuser wheel,
104 ... condensing optical system,
105 ... rod integrator,
106... Optical deflection control unit,
106R... red light deflection control section,
106G... Green light deflection control section,
106B... Blue light deflection control section,
110... afocal optical system,
111...Single-convex lens,
112... biconcave lens,
120... relay optical system,
121...Single-convex lens,
122... biconvex lens,
123...Single-convex lens,
130... internal total reflection prism (TIR prism),
131, 132 Prisms,
140... Projection optical system,
201B, 201G, 201R...light source section,
202B, 202G, 202R...light source units,
202BA, 202BB, 202BC... blue light source unit,
203B, 202G, 202R... Collimating lens,
204G, 204R optical elements,
204P... plane of incidence,
204Q... exit plane,
205 ... triangular prism,
210, 211...color synthesis mirror,
301... Lighting device,
302, 303, 304... reflecting mirrors,
305... Phosphor wheel,
306... dichroic mirror,
310... Afocal optical system for phosphor excitation,
311...Single-convex lens,
312... biconcave lens,
320... blue afocal optical system,
321...Single-convex lens,
322... biconcave lens,
330... Phosphor condensing lens,
331, 332...Single-convex lens,
340... color prism,
340B, 340G, 340R... Prisms,
360... drive motor,
360X... central axis,
361... Aluminum substrate,
362... Phosphor layer,
400 screen,
501, 502 ... partially reflective mirrors,
501s, 502s... slits,
L250, L251, L260, L261, L262... cross section,
B1, B2, B3...spot lights,
BB, BG, BR... light source blocks.

Claims (5)

A projection image display device comprising a first lighting device that outputs blue light, a second lighting device that outputs red light, and a third lighting device that outputs green light,
each of the second lighting device and the third lighting device includes: a light source unit including a plurality of semiconductor laser elements arranged in a two-dimensional direction;
a collimating lens arranged in front of the light source unit and configured to convert the traveling direction of the light beam emitted from each of the semiconductor lasers into substantially parallel light;
and at least one optical element arranged in front of the collimating lens and configured to change the traveling direction of the substantially parallel light only in a predetermined direction of one axis,
The optical element has optical transparency and has a first surface perpendicular to the substantially parallel light and a second surface inclined with respect to the first surface,
When the substantially parallel light is incident on the first surface, the optical element refracts the substantially parallel light at the second surface, thereby changing the traveling direction of the substantially parallel light only in the uniaxial direction, emitting an oblique luminous flux that is inclined with respect to the substantially parallel light, thereby forming an aspect of a screen composed of a plurality of spot lights output from the light source unit in a cross section at a predetermined position in the traveling direction of the oblique luminous flux; configured to change from a ratio to a predetermined aspect ratio;
The at least one optical element is composed of a plurality of triangular prisms,
A projection-type image display apparatus, wherein each of said triangular prisms is shifted by at least one semiconductor laser element of said light source unit with respect to the traveling direction of said substantially parallel light from said collimating lens. . 2. A projection image display apparatus according to claim 1, wherein said at least one optical element is composed of a triangular prism. 3. The projection image display apparatus according to claim 1, further comprising a reduction optical system for condensing the light flux that has passed through said optical element and for changing the light beam angle in the vertical and horizontal directions of the condensed light flux. . 4. The projection apparatus according to any one of claims 1 to 3, further comprising a triangular prism provided at a predetermined position in the direction of travel of said oblique light beam and further changing the direction of travel of said oblique light beam. type video display. Of claims 1 to 4, wherein screens composed of a plurality of spotlights output from light source units of the first lighting device, the second lighting device, and the third lighting device have different aspect ratios. The projection type image display device according to any one of .

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