JP2015022244A - Solid light source device and image projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid light source device for increasing light utilization efficiency by suppressing the deterioration of the condensed state of light from each solid light source on an object to be irradiated.SOLUTION: The solid light source device includes a plurality of solid light sources, individual lenses corresponding to the solid light sources respectively, and a condenser lens condensing the light emitted from each of the individual lenses. The center axis of the individual lenses is arranged to almost coincide with the position of the light-emitting point of each corresponding solid light source. The condenser lens comprises a first lens and a second lens. The first lens is a lens having positive power and the second lens is a lens having negative power.

Description

The present invention relates to a solid light source device and an image projection apparatus including the solid light source device.

  In various scenes such as conferences and educational sites, an image projection apparatus (hereinafter referred to as “projector”) that enlarges and displays a data image output from a personal computer is used. A light source device is mounted on the projector. In a conventional projector, an ultrahigh pressure mercury lamp with high luminous efficiency or a xenon lamp with good color reproducibility is used as a light source for a light source device.

  Since the brightness of a mercury lamp or the like decreases with the lighting time, when the usage time of about several thousand hours elapses, the brightness decreases to about half that at the start of use and needs to be replaced. On the other hand, light emitting diodes (hereinafter referred to as “LEDs”) and laser diodes (hereinafter referred to as “LDs”), which have a longer life than mercury lamps, are known, and projectors using these for light source devices are also known. Yes.

  Solid-state light sources such as LEDs and LDs have the disadvantage that their brightness is low compared to mercury lamps and the like. Therefore, when an LED or LD is used as the light source of the light source device, a plurality of LDs are arranged on a plane to increase the luminance.

  Since the LED has a large divergence angle, the use of the LED in the light source device tends to deteriorate the light utilization efficiency. Even if a plurality of LEDs are arranged, the LED capture angle that can be captured by the optical system at the subsequent stage is reduced due to optically defined etendue restrictions, resulting in poor light utilization efficiency.

  Also, the LD has a small light emitting area, a small light beam divergence angle, and therefore a high luminance, and the etendue is very small. Therefore, it is possible to obtain a projector light source with high luminance by arranging a large number of LDs in a dense matrix arrangement on a plane.

  When arranging a plurality of LDs as a light source for a projector, a method of arranging a rotating wheel on the optical path of light emitted from a number of LDs, separating the light according to time, and converting the color of each separated light It has been known. The rotating wheel is a member having transmission and reflection segments. The light emitted from the LD is condensed on the rotating wheel, and the light is separated according to the rotation timing of the rotating wheel.

  In this case, the problem is how to condense each light emitted from a large number of LDs onto the rotating wheel. This is because the light utilization efficiency in the optical system arranged at the subsequent stage of the rotating wheel is affected by whether or not the light can be condensed small on the rotating wheel. If the light utilization efficiency deteriorates, the brightness of the image displayed by the projector becomes dark.

  That is, condensing light emitted from a large number of LDs onto the rotating wheel is a very important factor as the performance of the solid-state light source device and the performance of the projector including the solid-state light source device. .

  In order to condense light emitted from each LD onto a rotating wheel, a method of decentering a collimator lens disposed corresponding to each LD is known. The relative misalignment error between the LD and the collimator lens is a factor that greatly deteriorates the light collection state on the rotating wheel. In order to cope with this, it is necessary to increase the accuracy of assembly of the collimator lens. In particular, even when decentering, it is necessary to increase the adjustment accuracy of the arrangement position, which causes a cost increase.

  There is also known a projector in which a condensing lens is arranged downstream of an LD and a collimator lens facing the LD without decentering the relative position of the LD and the collimator lens (see, for example, Patent Document 1).

  In the projector of Patent Document 1, in order to condense the light beam collimated by the collimator lens array by the condensing lens, the incident surface side of the condensing lens has a planar shape, and the exit surface side has a hyperboloid shape. Yes.

  When a plurality of LDs, which are solid light sources, are arranged to increase the brightness, the vicinity of the light source constituted by the LDs becomes very high. Therefore, it is desirable that the condenser lens is a glass lens that can ensure heat resistance. However, in a lens with a hyperboloid shape as in Patent Document 1, a glass mold lens is used to make a glass lens in order to ensure heat resistance. However, the glass mold lens is very expensive and becomes a large-diameter lens.

  Thus, using a large-diameter aspherical lens for the condenser lens leads to an increase in cost. In addition, the idea that the adjustment of the relative position between the solid light source and the collimator lens is not required by the condensing lens at the time of manufacture and the configuration thereof have not been studied so far.

  An object of this invention is to provide the solid light source device which can suppress degradation of the condensing state of the light from each solid light source on a to-be-irradiated body, and can improve light utilization efficiency.

  The present invention relates to a solid-state light source device, and a plurality of solid-state light sources, individual lenses corresponding to each of the solid-state light sources, a condensing lens that condenses light emitted from each of the individual lenses, The center axis of the individual lens is arranged so as to substantially coincide with the position of the light emitting point of each corresponding solid-state light source, and the condenser lens is composed of a first lens and a second lens, The main feature is that the first lens is a lens having positive power, and the second lens is a lens having negative power.

  ADVANTAGE OF THE INVENTION According to this invention, degradation of the condensing state of the light from each solid light source on a to-be-irradiated body can be suppressed, and light utilization efficiency can be improved.

It is a side view which shows the example of the solid light source device which concerns on this invention. It is a perspective view which shows the example of the said solid light source device. It is a top view which shows the example of arrangement | positioning of the solid light source with which the said solid light source device is equipped, and an individual lens. It is a side view which shows the example of arrangement | positioning of the said solid light source and an individual lens. It is a front view which shows the example of the rotation wheel with which the said solid light source is provided. It is a figure which shows the example of the ideal condensing state in the solid light source device which concerns on this invention. It is a figure which shows the example of the condensing state in the said solid light source device. It is a graph which shows the example of distribution of the condensing state in the solid light source device concerning the present invention. It is a graph which shows the example of distribution of the condensing state in the conventional solid light source device. It is an optical arrangement | positioning figure which shows another example of the solid light source device which concerns on this invention. It is a perspective view which shows another example of the solid light source device which concerns on this invention. It is a side view which shows another example of the solid light source device which concerns on this invention. It is an optical arrangement | positioning figure which shows the example of the illumination optical system with which the image projection apparatus which concerns on this invention is provided. It is an optical arrangement | positioning figure which shows the example of the image projection apparatus which concerns on this invention. It is a top view which shows the example of arrangement | positioning of the solid light source with which the conventional solid light source device is equipped, and an individual lens. It is a perspective view which shows the example of the conventional solid light source device.

  Hereinafter, embodiments of a solid-state light source device according to the present invention will be described with reference to the drawings.

First Embodiment of Solid Light Source Device FIG. 1 is a side view showing an example of the configuration of a solid light source device 10 according to the present embodiment. FIG. 1 is a diagram of the solid-state light source device 10 viewed from a direction orthogonal to the light emission direction. As shown in FIG. 1, the solid-state light source device 10 includes an LD 16, a collimator lens 17, a condenser lens 1 including a first condenser lens 11 and a second condenser lens 12, a folding mirror 14, and an irradiated object. And a rotating wheel 15. In FIG. 1, the central axis 13 of the solid state light source device 10 indicates the optical axes of the first condenser lens 11 and the second condenser lens 12. That is, the central axis 13 indicates the optical axis of the condenser lens 1.

  FIG. 2 is a perspective view of the solid-state light source device 10 according to the present embodiment. As shown in FIG. 2, in the solid light source device 10, a corresponding collimator lens 17 is disposed in front of each of the plurality of LDs 16 that are solid light sources. The light emitted from each collimator lens 17 is emitted through the first condenser lens 11 and the second condenser lens 12 in order. Thereafter, the light is reflected by the folding mirror 14 and collected on the rotating wheel 15 that is the irradiated object.

  The LD 16 is a solid light source, and a plurality of LDs 16 are arranged in a substantially annular arrangement on a plane. The collimator lens 17 is an individual lens that is similarly arranged corresponding to each LD 16.

  FIG. 3 is a plan view showing an example of the arrangement of the LD 16 and the collimator lens 17. As shown in FIG. 3, the LDs 16 are arranged on a circumference having a radius of 16 mm with the central axis 13 as the center. Further, the LDs 16 are arranged on a circumference having a radius of 26 mm with the central axis 13 as the center. In this embodiment, ten LDs 16 are arranged on the inner circumference, and eleven LDs 16 are arranged on the outer circumference. That is, in the solid-state light source device 10, a total of 21 LDs 16 are arranged in an annular shape.

  The light emitting area of the LD 16 is, for example, 1 μm × 28 μm. The light divergence angle in the LD 16 is 22 ° × 7 ° as a half-angle value that is 1 / e 2 of the maximum intensity. The wavelength of the emitted light is about 445 nm. That is, the LD 16 emits blue light.

  FIG. 4 is a side view showing an example of the arrangement relationship between the LD 16 and the collimator lens 17. As shown in FIG. 4, the position of the light emitting point of each LD 16 and the individual central axis of each collimator lens 17 are arranged to substantially coincide. The LD 16 is disposed so as to coincide with the front focal position of the collimator lens 17. As a result, the light emitted from the LD 16 passes through the collimator lens 17 and becomes parallel light.

Next, the specifications of the collimator lens 17 are shown in Table 1. The focal length f _CL of the collimator lens 17 is 6.8 mm.

  As shown in FIGS. 1 and 2, the parallel light emitted from each collimator lens 17 is incident on the condenser lens 1 including the first condenser lens 11 and the second condenser lens 12. The condenser lens 1 is arranged in the order of the first condenser lens 11 and the second condenser lens 12 from the LD 16 side (from the solid light source side).

Table 2 shows the specifications of the condenser lens 1, that is, the specifications of the first condenser lens 11 and the second condenser lens 12.

  The 1st condensing lens 11 is a lens provided with positive power, Comprising: Both an entrance surface and an output surface are convex shapes. The 2nd condensing lens 12 is a lens provided with negative power, Comprising: An entrance plane is concave shape, and an output surface is convex shape. The combined focal length f of the condenser lens 1 composed of these two lenses is 115 mm. That is, the combined focal length f of the condenser lens 1 is f ≦ 120 mm.

  The light emitted from the condensing lens 1 is condensed on the rotating wheel 15 that is an object to be irradiated via the folding mirror 14.

  FIG. 5 is a front view of the rotating wheel 15 as seen from the traveling direction of light. As shown in FIG. 5, the rotating wheel 15 is a disk-shaped member having a reflection band 51 and a transmission band 52. By controlling the rotation of the rotating wheel 15, the timing of light transmission and reflection can be controlled. Thereby, the light in the subsequent stage of the solid-state light source device 10 can be divided and colored to each light.

  Here, the solid-state light source device 10 is compared with the conventional example in which the light emitted from each LD 16 is condensed on the rotating wheel 15 without using the condensing lens 1 and the solid-state light source device 10 according to the present embodiment. The effect of will be described. In the conventional example, the collimator lens 17 is decentered with respect to the LD 16 so that the light emitted from each LD 16 is condensed on the rotating wheel 15. For example, as shown in FIG. 15, the individual central axes of the corresponding collimator lenses 17 are shifted toward the array center direction of the LDs 16.

  FIG. 16 is a perspective view showing an example of a solid state light source device 10a which is a conventional example in which the collimator lens 17 is decentered with respect to the LD 16. As shown in FIG. 16, the solid-state light source device 10 a which is the conventional example includes a plurality of LDs 16, a collimator lens 17 corresponding to the LDs 16, a mirror 71, an aperture mirror 72, and a lens 73. The solid-state light source device 10a has a configuration in which an optical path is folded by disposing two reflecting plates, that is, the mirror 71 and the opening mirror 72, between the rotating wheel 15 that is an irradiation object and the LD 16.

  In the solid-state light source device 10 a, the light emitted from the LD 16 is collimated by the collimator lens 17 and then reflected by the reflecting surface of the aperture mirror 72. The light reflected by the aperture mirror 72 is reflected again by the mirror 71 disposed between the collimator lens 17 and the aperture mirror 72. Thereafter, the light passes through an opening (hole) formed in the center of the opening mirror 72 and is condensed on the rotating wheel 15 by the lens 73.

  Each collimator lens 17 has a component tolerance and an assembly tolerance. Therefore, when manufacturing the solid light source device 10a, each collimator lens 17 may actually be assembled in a state deviating from the design value.

  6 and 7 are diagrams illustrating an example of a state where the light emitted from the LD 16 is condensed on the rotating wheel 15 (condensing state). The condensing state shown in FIGS. 6 and 7 is data in which models of the solid state light source device 10 and the conventional solid state light source device 10a are created on a computer program and the illuminance distribution on the rotating wheel 15 is simulated. . 6 and 7, the vertical and horizontal scales indicate coordinates on the rotating wheel 15 that is an object to be irradiated. The coordinates (0, 0) indicate a position that matches the central axis 13 of the solid-state light source device 10 according to the present embodiment. FIG. 6 is an example of a light collection state on the rotating wheel 15 when the LD 16 and the collimator lens 17 are arranged as designed.

  Since the collimator lens 17 has component tolerances and the like, the condensing state is not actually as shown in FIG. 6 due to the influence thereof, but becomes a condensing state as shown in FIG. FIG. 7 shows a condensing state of light emitted from each LD 16 in consideration of component tolerance and the like. As shown in FIG. 7, the actual condensing positions are distributed at positions scattered in each direction from the vicinity of the center (0, 0).

  In a condensing state as shown in FIG. 7, a region 91 that surrounds the condensing position on the rotary wheel 15 up to a position farthest from the center is defined as a combined beam diameter.

  A description will be given of the distribution of the combined beam diameter when assuming the positional deviation of each collimator lens 17 due to the component tolerance and the assembly tolerance of the collimator lens 17 at the time of manufacturing the conventional solid-state light source device 10a. For example, the amount of displacement of each collimator lens 17 is within a range of ± 0.18 mm in the y-axis direction, ± 0.2 mm in the z-axis direction, and a tilt angle in the yz plane of ± 0.14 ° shown in FIG. Are assumed to occur along a distribution of 3σ. Under this assumption, the distribution of the combined beam diameter at the condensing position on the rotating wheel 15 is as shown in FIG. FIG. 9 is a graph showing an example of the distribution of the combined beam diameter in the conventional solid-state light source device 10a. The horizontal axis is the combined beam diameter, and the vertical axis is the frequency.

  On the other hand, in the solid-state light source device 10 according to the present embodiment, when the distribution of the positional deviation of each collimator lens is the same as described above, the distribution of the combined beam diameter at the condensing position on the rotating wheel 15 is shown in FIG. It becomes like this. FIG. 8 is a graph showing an example of the distribution of the combined beam diameter in the solid-state light source device 10. The horizontal axis is the combined beam diameter, and the vertical axis is the frequency.

  In the solid-state light source device 10 according to the present embodiment, the central value of the distribution of the combined beam diameter is about 8 mm. In the conventional solid-state light source device 10a, the central value of the distribution of the combined beam diameter is about 14 mm.

  As is clear from the comparison between the graph of FIG. 8 and the graph of FIG. 9, the configuration of the solid-state light source device 10 that collects light using the first condenser lens 11 and the second condenser lens 12 is reflected by two mirrors. The combined beam diameter is smaller than the condensing configuration.

  In the conventional solid-state light source device 10a, due to an error in the displacement of the collimator lens 17, the variation in the condensing position is increased and the combined beam diameter is increased. As a result, the light utilization efficiency in the subsequent optical system is lowered. In order to correct this, it is necessary to accurately adjust the position of the LD 16 and the position of the collimator lens 17 during the manufacture of the solid light source device 10a, leading to an increase in manufacturing cost.

  In contrast, the solid-state light source device 10 according to the present embodiment includes the positions of the light emitting points of the LDs 16 arranged on the plane with a substantially annular arrangement, the individual central axes of the collimator lenses 17 corresponding to the respective LDs 16, and Are arranged so as to substantially match. Furthermore, a two-lens condensing lens 1 is disposed between the collimator lens 17 and the rotating wheel 15 that is the object to be irradiated. As a result, the variation in the condensing position when the light is condensed on the rotating wheel 15 is suppressed.

  That is, according to the solid-state light source device 10, a position adjustment jig between the LD 16 and the collimator lens 17 at the time of manufacture becomes unnecessary. Therefore, the manufacturing cost can be reduced.

The focal length f _CL of the collimator lens 17 used in the solid-state light source device 10 already described is 6.8 mm, and the combined focal length f of the condenser lens 1 is 115 mm. Consider a positional deviation at the time of arrangement between the position of the light emitting point of each LD 16 fixed at the time of manufacturing the solid-state light source device 10 and the individual central axis of the collimator lens 17 corresponding thereto. If the maximum value of the relative displacement between the LD 16 and the collimator lens 17 is ypos, 10 · f _CL / f is 0.6, so that the conditional expression: ypos <10 · f _CL / f is satisfied. Become. In other words, ypos is an allowable value of relative displacement in the above conditional expression.

  “10” in the above formula represents the radius of the combined beam diameter on the rotating wheel 15. The radius of the combined beam diameter is not limited to “10”.

When the radius of the combined beam diameter increases, the allowable value ypos of the positional deviation increases. Thereby, the diameter of the rotating wheel 15 is increased, and the solid state light source device 100 is increased in size. Therefore, the focal length f _CL of the LD 16 and the collimator lens 17 at the time of manufacture and the combined focal length f of the condenser lens 1 are defined to be 10 · f _CL / f or less. Thereby, according to the solid-state light source device 10, the allowable value ypos of the positional deviation between the LD 16 and the collimator lens 17 can be relaxed.

Further, as described with reference to FIG. 3, the LDs 16 are arranged on a plane with a substantially annular arrangement. The distance to the center of the LD 16 on the outer ring is Φ (26 mm in FIG. 3). The angle θ formed between the principal ray of the light emitted from the LD 16 on the outer ring and the central axis 13 is θ = tan ⁻¹ (Φ / f). In the solid-state light source device 10 according to the present embodiment, θ is 10.2 °.

  In other words, the direction lines of light emitted from the plurality of LDs 16 intersect with the central axis 13 of the condenser lens after being refracted by the condenser lens 1. The angle is within 20 degrees.

  Further, the smaller this value (angle), the easier it is for light to be captured by a subsequent optical system, and the use of the solid-state light source device 100 for the image projection device can improve the light utilization efficiency.

Embodiment of Illumination Optical System Next, another example of the solid state light source device according to the present invention will be shown. FIG. 10 is an optical layout diagram illustrating an example of the solid-state light source device 20 according to the present embodiment.

  In FIG. 10, detailed description of the same configuration as that of the already described solid-state light source device 10 is omitted. The blue light emitted from the LD 16 that is a solid light source is converted into parallel light by the collimator lens 17, and is further condensed by the first condenser lens 11 and the second condenser lens 12 onto the rotating wheel 15 that is the irradiated object. Is done.

  In the rotating wheel 15, the transmission band 52 and the reflection band 51 are temporally switched as described with reference to FIG. 5. The light from the LD 16 incident on the rotating wheel 15 at the timing of the transmission band 52 passes through the first lens 121, the first dichroic mirror 136, the second lens 122, the third lens 123, the fourth lens 124, and the fifth lens 125. It passes through and enters the phosphor 139. Blue light incident on the phosphor 139 is converted into green light.

  The converted green light again passes through the fifth lens 125, the fourth lens 124, the third lens 123, and the second lens 122, and is reflected by the first dichroic mirror 136. The reflected green light passes through the sixth lens lens 126 and the seventh lens 127 and is reflected by the second dichroic mirror 137 and the third dichroic mirror 138. Thereafter, the light passes through the eighth lens 128 and the ninth lens 129 and enters the light tunnel 141.

  On the other hand, the blue light incident on the rotating wheel 15 at the timing of the reflection band 51 passes through the tenth lens 134, the eleventh lens 135, and the third dichroic mirror 138 after being reflected by the rotating wheel 15. Thereafter, the light passes through the eighth lens 128 and the ninth lens 129 and enters the light tunnel 141.

  The red light source 140 is a solid light source that emits red light, and passes through the twelfth lens 130, the thirteenth lens 131, the fourteenth lens 132, the fifteenth lens 133, and the second dichroic mirror 137. Thereafter, the light is reflected by the third dichroic mirror 138, passes through the eighth lens 128 and the ninth lens 129, and enters the light tunnel 141.

  As described above, the solid-state light source device 20 can make light of three colors, red, green, and blue, enter the light tunnel 141. The light tunnel 141 has a structure in which multiple reflections are repeated inside. As a result, the light of each color becomes light with uniform distribution near the exit of the light tunnel 141.

  In order to control the color of the light emitted from the light tunnel 141, the light emission timing of the LD 16 emitting blue light or the red light source 140 emitting red light and the timing of the rotating wheel 15 may be controlled.

  According to the solid-state light source device 20 described above, a high-intensity solid-state light source device using a laser light source as a solid-state light source has high light utilization efficiency, high efficiency, good color reproducibility, and long life. An optical system can be obtained.

Second Embodiment of Solid State Light Source Device Next, still another embodiment of the solid state light source device according to the present invention will be described with reference to the drawings. FIG. 11 is a perspective view illustrating an example of the solid-state light source device 30 according to the present embodiment. As shown in FIG. 11, the solid-state light source device 30 includes an LD 16, a collimator lens 17, a first condenser lens 11, a second condenser lens 12 a, and an aperture mirror 62.

  Since the LD 16, the collimator lens 17, and the first condenser lens 11 are the same as those of the solid-state light source device 10 already described, detailed description thereof is omitted.

  The second condenser lens 12a has a reflection portion 301 formed on the exit surface side. The reflection part 301 is formed by applying a reflection film to a part of the central portion on the lens surface on the emission side of the second condenser lens 12a.

  The aperture mirror 62 has an opening (hole) of a predetermined size at the center. That is, the aperture mirror 62 is a reflecting member having an opening. The reflecting surface of the aperture mirror 62 is directed to the second condenser lens 12a side.

  Part of the light that has passed through the vicinity of the center of the second condenser lens 12 a passes through the opening of the aperture mirror 62 and is collected on the rotating wheel 15. A part of the light that has passed outside the center of the second condenser lens 12 a hits the reflecting member without passing through the opening of the aperture mirror 62. The light hitting the reflecting member is reflected toward the second collector mirror 12a side. The light reflected by the aperture mirror 62 strikes the reflection part 301 of the second condenser mirror 12a. The light reflected by the reflecting portion 301 to the aperture mirror 62 again passes through the aperture of the aperture mirror 62 and is collected on the rotating wheel 15.

  As described above, the light path from the light emitted from the LD 16 to the rotating wheel 15 is folded by the condensing mirror 12 a having the reflecting portion 301 and the aperture mirror 62. Thus, when the distance from the LD 16 to the rotating wheel 15 in the solid-state light source device 10 already described (the sum of a and b shown in FIG. 1) is compared with the distance from the LD 16 to the rotating wheel 15 in the solid-state light source device 30. The solid light source device 30 is shorter. That is, according to the solid light source device 30, a smaller light source device can be obtained.

Third Embodiment of Solid Light Source Device Next, still another embodiment of the solid light source device according to the present invention will be described with reference to the drawings. FIG. 12 is a side view showing an example of the solid state light source device 40 according to the present embodiment. As shown in FIG. 12, the solid-state light source device 40 includes an LED 18 that is an LED light source, a collimator lens 17, and a condenser lens 1 including a first condenser lens 11 and a second condenser lens 12. Become. In FIG. 12, the central axis 13 of the solid light source device 40 indicates the optical axis of the first condenser lens 11 and the second condenser lens 12, that is, the optical axis of the condenser lens 1.

  The solid light source device 40 has a configuration different from that of the solid light source device 10 and uses an LED 18 as a light source instead of the LD 16. Hereinafter, the points different from the above will be described in detail.

  In the solid light source device 40, as in the solid light source device 10, 21 LEDs 18 are arranged on a plane with a substantially annular arrangement. The 21 LEDs 18 are arranged in an appropriate number of three colors of red, green, and blue. Here, the appropriate number is a number capable of obtaining desired white light. In addition, the distribution of the incident angles to the light tunnel 141 is also the number of approximate values in red, green, and blue.

  The solid-state light source device 40 can synthesize desired colors if light emitted from the solid-state light source is incident on the light tunnel 141. Therefore, the light emitted from each LED 18 becomes substantially parallel light in the collimator lens 17 corresponding to each LED 18, and then passes through the first condenser lens 11 and the second condenser lens 12 and is reflected by the folding mirror 14. Reflected. Thereafter, the light enters the light tunnel 141.

  Each light incident on the light tunnel 141 becomes light with uniform illuminance distribution at the exit end of the light tunnel 141 after repeated multiple reflection.

  As described above, according to the solid-state light source device 40, by using the LED 18 as a light source, a light source device that is compact, has good color reproducibility, and has a long life can be obtained.

Embodiment of Image Projection Device Next, an embodiment of an image projection device according to the present invention will be described with reference to the drawings. First, the illumination optical system 142 used in the projector 1000 according to the present embodiment will be described with reference to FIG.

  FIG. 13 is an optical arrangement diagram showing an example of the illumination optical system 142 according to the present embodiment. As shown in FIG. 13, the illumination optical system 142 includes a first illumination lens 143, a second illumination lens 144, a plane mirror 145, and a concave mirror 146.

  The light of each color emitted from the light tunnel 141 already described passes through the first illumination lens 143 and the second illumination lens 144 and is reflected in the order of the plane mirror 145 and the concave mirror 146, and then spatially modulated. The element 147 is irradiated. The spatial modulation element 147 is, for example, a DMD (Digital Micromirror Device). The DMD is an element in which micromirrors are two-dimensionally arranged and an image is formed by controlling the angle of each mirror corresponding to one pixel of the image. The illumination optical system 142 is from the first illumination lens 143 to the concave mirror 146. By this illumination optical system 142, the emission end face of the light tunnel 141 and the spatial modulation element 147 have a conjugate relationship. Therefore, the spatial modulation element 147 is illuminated with the exit end face of the light tunnel 141 as the object plane.

  Here, DMD will be described. In the DMD, square mirrors each having a side of about 10 μm are arranged corresponding to display pixels. For example, 1280 × 800 mirrors are arranged to display an image at the resolution of the WXGA standard.

Each mirror has a square shape and can form an inclination of ± 12 degrees in a diagonal direction. This inclination is switched according to the video signal.
For example, when the +12 degree state is set to the ON state, the light that illuminates the DMD by the illumination optical system 142 is reflected only in the direction of the projection optical system 148 by the mirror part in the ON state. An image is formed by the light reflected to the projection optical system 148.

  In addition, when the -12 degree state is set to the OFF state, the light that illuminates the DMD by the illumination optical system 142 is reflected in a direction different from the projection optical system 148 from the mirror part light in the OFF state. This reflection hole is absorbed by an absorption member or the like disposed in the housing of the illumination optical system 142. Pixels corresponding to the mirror part in the OFF state are expressed in black in the image.

  Next, the projector 1000 according to the present embodiment will be described. FIG. 14 is an optical layout diagram showing an example of a projector 1000 provided with the solid-state light source device according to the present invention described so far.

  As shown in FIG. 14, the projector 1000 includes the solid-state light source device 100, an illumination optical system 142, and a projection optical system 148.

  Green and blue light is generated at the timing of the blue LD 16 and the rotating wheel 15, and the light emission timing of the red LD or red LED is controlled to control the color of the light emitted from the light tunnel 141 in a time-sharing manner. In synchronization with this light color control, the timing of the ON state and OFF state of each mirror of the DMD already described is controlled. By these controls, video of each color can be enlarged and projected onto the screen 149 which is a projection surface through the projection optical system 148 in a time division manner.

  According to the projector 1000 described above, it is possible to obtain an image projection apparatus that has a good color reproducibility and has a long life and a light source device.

DESCRIPTION OF SYMBOLS 1 Condensing lens 10 Solid light source device 11 1st condensing lens 12 2nd condensing lens 13 Central axis 14 Folding mirror 15 Rotating wheel 16 LD
17 Collimator lens

JP 2012-48832 A

Claims (11)

A plurality of solid state light sources;
An individual lens corresponding to each of the solid state light sources;
A condensing lens that condenses the light emitted from each of the individual lenses,
The central axis of the individual lens is disposed so as to substantially coincide with the position of the light emitting point of each corresponding solid-state light source,
The condensing lens is composed of a first lens and a second lens,
The first lens is a lens having positive power;
The second lens is a lens having negative power.
A solid-state light source device.   The solid-state light source device according to claim 1, wherein the second lens has a concave incident surface and a convex emission surface.   The solid light source device according to claim 1, wherein the solid light sources are arranged in a substantially annular arrangement on a plane.   The solid-state light source device according to any one of claims 1 to 3, wherein the condensing lens includes the first lens and the second lens arranged in order from the solid-state light source side.   The solid-state light source device according to claim 1, wherein the second lens includes a reflection unit. A reflective member having an opening;
The light emitted from the second lens is reflected by the reflecting member having the opening and then reflected by the reflecting portion of the second lens, and passes through the opening.
The solid light source device according to claim 5.   7. The solid-state light source device according to claim 1, wherein f <120 mm, where f is a combined focal length of the one lens and the second lens. The focal length of the individual lens is f _CL ,
The combined focal length of the condenser lens is f,
8. The solid according to claim 7, wherein ypos is a maximum value of a relative positional shift between the central axis of the solid-state light source and the central axis of the individual lens at the time of manufacture. Light source device.
Conditional expression: ypos <10 · f _CL / f The chief ray of light emitted from the plurality of solid state light sources intersects with the central axis of the condenser lens after being refracted by the condenser lens, and is within 20 degrees.
The solid light source device according to claim 1.   The solid light source device according to claim 1, wherein the solid light source is a laser light source. A solid state light source device;
An illumination optical system that receives light from the solid-state light source device and emits illumination light; and
A spatial modulation element that is illuminated with illumination light from the illumination optical system to form an image;
A projection optical system that projects an image formed in the spatial modulation element onto a projection surface;
An image projection apparatus comprising:
The solid-state light source device is the solid-state light source device according to any one of claims 1 to 10.
An image projection apparatus characterized by that.