JP6303608B2 - Light source device and projector - Google Patents

Description

  The present invention relates to a light source device and a projector.

  In order to reduce the size of the optical system, a light source device is known in which two semiconductor lasers having different emission colors are mounted in one package to shorten the interval between the light emitting units (for example, Patent Document 1). reference).

  In this specification, the ratio of the amount of light incident on the subsequent optical system to the amount of light emitted from the light source device may be referred to as “optical efficiency”. For example, a large amount of light incident on a subsequent optical system out of light emitted from the light source device may be referred to as “high optical efficiency”. On the contrary, when the light emitted from the light source device is small in the light incident on the subsequent optical system, it may be referred to as “low optical efficiency”.

JP 2010-40443 A

  Since the light emitted from the semiconductor laser is diffused light, a collimating lens that converts the diffused light into parallel light is required to efficiently enter the light into the subsequent optical system. Therefore, in Patent Document 1, when a collimating lens is provided in each of the two light emitting units having a short interval, the light emitted from the collimating lens is affected by the alignment deviation because the focal length of the collimating lens is short. Cheap. For this reason, the optical efficiency of the light source device as a whole may be reduced. On the other hand, it is conceivable to provide one collimating lens for the two light emitting units. In this case, the light emitted from each light source is emitted in different directions after passing through the collimating lens. Therefore, in this case as well, the optical efficiency of the light source device as a whole may be reduced.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a light source device capable of obtaining high optical efficiency even when the interval between the light emitting portions is shortened. It is another object of the present invention to provide a projector capable of displaying an image with high brightness using such a light source device.

In order to solve the above problems, according to one embodiment of the present invention, a first light-emitting device that emits a plurality of light beams including a first light beam and a second light beam, and the plurality of light beams are incident And a first photorefractive element on which the first light beam transmitted through the first collimator lens is incident. The second light beam is the first light. Providing a light source device that passes through a region outside the refraction element, and wherein the first light refraction element is configured to reduce an angle formed by the first light beam and the second light beam. .
In order to solve the above problems, according to one embodiment of the present invention, a first light-emitting device that emits a plurality of light beams including a first light beam and a second light beam, and the plurality of light beams are incident And a first photorefractive element on which the first light beam transmitted through the first collimator lens is incident. The second light beam is the first light. The first light refracting element passes through a region outside the refracting element, and the first light refracting element is configured to reduce an angle formed by the first light beam and the second light beam. A second light-emitting device that emits a beam and a fourth light beam, a second collimator lens on which the third light beam and the fourth light beam are incident, and the second collimator lens. A second photorefractive element on which the third light beam is incident; And a connecting portion that connects the second photorefractive element to the second photorefractive element, wherein the fourth light beam passes through a region outside the second photorefractive element, and The photorefractive element provides a light source device configured to reduce an angle formed by the third light beam and the fourth light beam.

  According to this configuration, an angle between the second light beam and the first light beam emitted from the first light refracting element is reduced, and the optical system disposed at the subsequent stage of the first light refracting element is used. The first light beam and the second light beam are likely to enter. Therefore, an optical device with high optical efficiency can be obtained.

  In the present specification, “the angle formed by the first light beam and the second light beam” is any of the principal ray axis of the first light beam and the principal ray axis of the second light beam. When the projection onto a virtual plane parallel to one principal ray axis is considered, it means the maximum angle formed by the principal ray axis of the first light beam and the principal ray axis of the second light beam. Specifically, there are an infinite number of virtual surfaces parallel to one principal ray axis, and the angle formed by the two light beams changes if the setting of the virtual surface changes. Therefore, the virtual plane is set so that the angle formed by the two light beams is maximized.

In one aspect of the present invention, if the angle formed by the first light beam immediately after passing through the first collimator lens and the second light beam immediately after passing through the first collimator lens is θ. The first photorefractive element may be configured such that an angle formed by the first light beam and the second light beam is larger than 0 and smaller than θ.
According to this configuration, by using the first photorefractive element, the angle formed between the first light beam and the second light beam is such that the first light beam and the second light beam immediately after the collimator lens. Smaller than the angle between Therefore, the first light beam and the second light beam are easily incident on the optical system disposed at the subsequent stage of the first photorefractive element, and an optical device with high optical efficiency can be obtained.

In one aspect of the present invention, the first light emitting device includes a first light emitting surface that emits the first light beam, and a second light emitting surface that emits the second light beam. A plurality of light emitting surfaces may be provided, the plurality of light emitting surfaces may be disposed on a predetermined plane, and a focal point of the first collimator lens may be positioned on the predetermined plane.
According to this configuration, since the first light beam and the second light beam emitted from the collimator lens are collimated, the light source device can be easily incident on the subsequent optical system and has high optical efficiency. .

In one aspect of the present invention, the optical axis of the first collimator lens may be perpendicular to the predetermined plane.
According to this configuration, a light source device with high optical efficiency can be obtained in the subsequent optical system.

In one aspect of the present invention, an integrator is provided that uniformizes the intensity distribution of the light flux emitted from the first collimator lens, and the first photorefractive element includes the first collimator lens and the integrator. It is good also as a structure arrange | positioned on the optical path between.
According to this structure, it can be set as the light source device which can perform uniform light irradiation in a to-be-irradiated surface.

In one aspect of the present invention, a light diffusing element may be provided between the integrator and the first photorefractive element.
According to this configuration, since the illuminance distribution in the exit pupil can be widened, it is possible to provide a light source device capable of reducing speckle when the light beam has coherence.

In one aspect of the present invention, the optical axis of the first collimator lens may be configured to coincide with the principal ray axis of the second light beam.
According to this configuration, since the principal ray axis of the second light beam emitted from the collimator lens is parallel to the optical axis of the collimator lens, the emission direction of the first light beam and the second light beam can be reduced. Control becomes easy.

In one embodiment of the present invention, the first light beam and the second light beam may have the same wavelength.
According to this configuration, a light source device that emits strong light of a single color and has high optical efficiency can be obtained.

In one embodiment of the present invention, a second light-emitting device that emits a third light beam and a fourth light beam, and a second light-emitting device on which the third light beam and the fourth light beam are incident A collimator lens, a second photorefractive element on which the third light beam transmitted through the second collimator lens is incident, and a connection for connecting the first photorefractive element and the second photorefractive element The fourth light beam passes through a region outside the second photorefractive element, and the second photorefractive element includes the third light beam and the fourth light beam. The angle formed with the light beam may be reduced.
According to this configuration, the first photorefractive element and the second photorefractive element form an array structure that is connected to each other by the connecting portion. Therefore, compared with the case where each photorefractive element is provided individually, a light source device with a reduced number of parts and a simplified configuration can be obtained.

In one embodiment of the present invention, a third light-emitting device that emits a fifth light beam and a sixth light beam, and a third light-emitting device on which the fifth light beam and the sixth light beam are incident A collimator lens, the fifth light beam transmitted through the third collimator lens is incident on the first light refraction element, and the sixth light beam is the first light refraction element. The first photorefractive element may be configured to reduce an angle formed by the fifth light beam and the sixth light beam.
According to this configuration, the emission direction of the light beam of the first light emitting device and the third light emitting device can be adjusted by one first photorefractive element, thereby reducing the number of components and simplifying the configuration. The light source device can be made.

In one embodiment of the present invention, the light emitting device may be a laser light source.
According to this configuration, a light source device using a laser light source and high optical efficiency can be realized.

One aspect of the present invention is a projector including the light source device described above, a light modulation element that modulates light emitted from the light source device, and a projection optical system that projects light modulated by the light modulation element. provide.
According to this configuration, a projector capable of displaying an image with high luminance can be obtained.

It is a schematic diagram which shows the projector of this embodiment. It is a schematic diagram which shows the light source part which the light source device of this embodiment has. It is a schematic explanatory drawing of a polarization conversion element. It is a schematic diagram of the calculation result which shows the angle distribution of a 1st light beam and a 2nd light beam. It is explanatory drawing which shows the modification of a light source part.

  Hereinafter, the light source device and the projector according to the present embodiment will be described with reference to FIGS. In all the drawings below, the dimensions and ratios of the constituent elements are appropriately changed in order to make the drawings easy to see.

  FIG. 1 is a schematic diagram showing a projector PJ of this embodiment. As shown in the figure, the projector PJ includes a light source device 100, a field lens 300R, a field lens 300G, a field lens 300B, a liquid crystal light valve (light modulation element) 400R, a liquid crystal light valve (light modulation element) 400G, and a liquid crystal. A light valve (light modulation element) 400B, a color composition element 500, and a projection optical system 600 are included.

  The light source device 100 includes a light source unit 110, a lens array 120, a lens array 130, a polarization conversion element 140, and a superimposing lens 150. The projector PJ includes, as the light source device 100, a light source device 100R that emits red light, a light source device 100G that emits green light, and a light source device 100B that emits blue light.

The projector PJ generally operates as follows. The color light emitted from the light source device 100R enters the liquid crystal light valve 400R via the field lens 300R and is modulated. Similarly, the color light emitted from the light source device 100G enters the liquid crystal light valve 400G and is modulated, and the color light emitted from the light source device 100B enters the liquid crystal light valve 400B and is modulated. A plurality of color lights modulated by the liquid crystal light valve 400R, the liquid crystal light valve 400G, and the liquid crystal light valve 400B are incident on the color synthesis element 500 and synthesized. The light synthesized by the color synthesizing element 500 is enlarged and projected by a projection optical system 600 onto a screen SCR such as a wall or a screen, and a full-color projection image is displayed.
Hereinafter, each component of the projector PJ will be described.

  FIG. 2 is a schematic diagram illustrating the light source unit 110 included in the light source device 100. The light source unit 110 includes a light emitting device (first light emitting device) 10, a collimator lens (first collimator lens) 20, and a photorefractive element (first photorefractive element) 30.

  The light emitting device 10 includes a first light source 11 that emits a first light beam LB1 and a second light source 12 that emits a second light beam LB2. The light emitting device 10 of the present embodiment is a laser light source. The light emitting surface of the first light source 11 is the first light emitting surface 11s, and the light emitting surface of the second light source 12 is the second light emitting surface 12s. The first light emitting surface 11s and the second light emitting surface 12s are arranged on a predetermined plane.

  In the present embodiment, the light emitting device 10 emits light having the same wavelength as the first light beam LB1 and the second light beam LB2. Thereby, it is possible to obtain the light source device 100 that emits strong light of a single color and has high optical efficiency.

  In FIG. 2, the principal ray axis of the first light beam LB1 is denoted by reference symbol RA1, and the principal ray axis of the second light beam LB2 is denoted by reference symbol RA2. Further, the first light beam LB1 and the second light beam LB2 are illustrated as being both diffused light.

  The collimator lens 20 is a lens that collimates the first light beam LB1 and the second light beam LB2 emitted from the light emitting device 10. In the collimator lens 20, the focal point 20 p on the light emitting device 10 side (incident side) is located on the second light emitting surface 12 s of the second light source 12. The optical axis 20ax of the collimator lens 20 is coincident with the principal ray axis RA2 of the second light beam LB2. Further, the optical axis 20ax of the collimator lens 20 is perpendicular to the first light emitting surface 11s and the second light emitting surface 12s (predetermined plane).

  Therefore, the second light beam LB2 emitted from the collimator lens 20 is collimated and emitted in the same direction as the optical axis 20ax of the collimator lens 20.

  On the other hand, the first light beam LB1 has the principal ray axis RA1 oriented in the same direction as the optical axis 20ax of the collimator lens 20, but is shifted in position. Therefore, the first light beam LB1 emitted from the collimator lens 20 is collimated but emitted in a direction different from that of the second light beam LB2.

  In FIG. 2, an angle formed by the first light beam LB1 and the second light beam LB2 emitted from the collimator lens 20 is indicated as θ.

  The first light beam LB1 transmitted through the collimator lens 20 enters the photorefractive element 30, and refracts the first light beam LB1. The photorefractive element 30 is arranged so as to pass through the region outside the photorefractive element 30 without the second light beam LB2 being incident.

  The photorefractive element 30 is configured to reduce the angle formed by the first light beam LB1 and the second light beam LB2. Specifically, the light refraction element 30 makes the angle formed by the first light beam LB1 and the second light beam LB2 smaller than before the first light beam LB1 enters the light refraction element 30. More specifically, the photorefractive element 30 is configured such that the angle formed by the second light beam LB2 and the first light beam LB1 immediately after passing through the photorefractive element 30 is 0 or more and smaller than θ. Yes. In FIG. 2, the first light beam LB1 emitted from the photorefractive element 30 and the second light beam LB2 emitted from the collimator lens 20 are shown as having the principal ray axes parallel to each other. The refraction angle of the first light beam LB1 incident on the photorefractive element 30 can be obtained by Snell's law.

  The lens array 120 and the lens array 130 are integrators that uniformize the intensity distribution of the light emitted from the light emitting device 10. For this reason, the photorefractive element 30 is disposed on the optical path between the collimator lens 20 and the integrator.

  The lens array 120 includes a plurality of first small lenses 122, and the lens array 130 includes a plurality of second small lenses 132. The plurality of first small lenses 122 correspond to the plurality of second small lenses 132 on a one-to-one basis. The light emitted from the light emitting device 10 is spatially divided and incident on the plurality of first small lenses 122. The first small lens 122 causes the incident light to form an image on the corresponding second small lens 132. Thereby, a secondary light source image is formed on each of the plurality of second small lenses 132. Note that the outer shapes of the first small lens 122 and the second small lens 132 are substantially similar to the outer shapes of the image forming regions of the liquid crystal light valve 400R, the liquid crystal light valve 400G, and the liquid crystal light valve 400B.

  The polarization conversion element 140 aligns the polarization state of the light L emitted from the lens array 120 and the lens array 130. FIG. 3 is a schematic explanatory diagram of the polarization conversion element.

  As shown in the figure, the polarization conversion element 140 includes a plurality of polarization conversion cells 141. The plurality of polarization conversion cells 141 correspond to the plurality of second small lenses 132 on a one-to-one basis. The light L from the secondary light source image formed on the second small lens 132 enters the incident region 142 of the polarization conversion cell 141 corresponding to the second small lens 132.

  Each polarization conversion cell 141 is provided with a polarization beam splitter film 143 (hereinafter referred to as a PBS film 143) and a phase difference plate 145 corresponding to the incident region 142. The light L incident on the incident region 142 is separated by the PBS film 143 into P-polarized light L1 and S-polarized light L2 with respect to the PBS film 143. One of the P-polarized light L1 and the S-polarized light L2 (here, S-polarized light L2) is reflected by the reflecting member 144 and then enters the phase difference plate 145. The S-polarized light L2 that has entered the phase difference plate 145 is converted into the polarization state of the other polarization (here, P-polarized light L1) by the phase difference plate 145, becomes P-polarized light L3, and is emitted together with the P-polarized light L1. .

  The superimposing lens 150 superimposes the light emitted from the polarization conversion element 140 in the illuminated area. The light emitted from the light emitting device 10 is spatially divided and then superposed, whereby the intensity distribution is made uniform and the axial symmetry around the light axis is enhanced.

  The red light R emitted from the light source device 100R enters the field lens 300R. The red light R is collimated by the field lens 300R and then enters the liquid crystal light valve 400R. Similarly, the green light G emitted from the light source device 100G is collimated by the field lens 300G and then enters the liquid crystal light valve 400G. The blue light B emitted from the light source device 100B is collimated by the field lens 300B and then enters the liquid crystal light valve 400B.

  The liquid crystal light valve 400R, the liquid crystal light valve 400G, and the liquid crystal light valve 400B are configured by a light modulation device such as a transmissive liquid crystal light valve. The liquid crystal light valve 400R, the liquid crystal light valve 400G, and the liquid crystal light valve 400B are electrically connected to a signal source (not shown) such as a PC that supplies an image signal including image information. The liquid crystal light valve 400R, the liquid crystal light valve 400G, and the liquid crystal light valve 400B modulate the incident light for each pixel based on the supplied image signal to form an image. The liquid crystal light valve 400R, the liquid crystal light valve 400G, and the liquid crystal light valve 400B form a red image, a green image, and a blue image, respectively. Light (formed image) modulated by the liquid crystal light valve 400R, the liquid crystal light valve 400G, and the liquid crystal light valve 400B is incident on the color composition element 500.

The color composition element 500 is configured by a dichroic prism or the like. The dichroic prism has a structure in which four triangular prisms are bonded to each other. The surface to be bonded in the triangular prism becomes the inner surface of the dichroic prism. On the inner surface of the dichroic prism, a mirror surface that reflects red light and transmits green light and a mirror surface that reflects blue light and transmits green light are formed orthogonal to each other. The green light incident on the dichroic prism is emitted as it is through the mirror surface. The red light and blue light incident on the dichroic prism are selectively reflected or transmitted by the mirror surface and emitted in the same direction as the emission direction of the green light. In this way, the three color lights (images) are superimposed and combined, and the combined color light is enlarged and projected onto the screen SCR by the projection optical system 600.
The projector PJ of this embodiment has the above configuration.

  FIG. 4 shows angular distributions of the first light beam LB1 and the second light beam LB2 on a plane orthogonal to the principal ray axis of the second light beam LB2 when entering the lens array 120 shown in FIG. It is a schematic diagram of the calculation result shown. In FIG. 4, the intersection of the a axis and the b axis is the origin.

  4A and 4B show the case where the photorefractive element 30 shown in FIG. 2 is not used, and FIGS. 4C to 4F show the case where the photorefractive element 30 is used.

  Further, FIGS. 4C and 4D show a case where the principal ray axes of the first light beam and the second light beam are made parallel by the photorefractive element 30. 4E and 4F show the case where the angle formed by the principal ray axes of the first light beam and the second light beam is smaller than that in the case where the photorefractive element 30 is not used. Show.

  FIGS. 4A, 4C, and 4E show the angular distributions of the first light beam and the second light beam when the principal ray axis of the second light beam is the origin. In FIG. 4, the irradiation angle distribution of the first light beam in a plane orthogonal to the principal ray axis of the second light beam is denoted by reference numeral S1, and the irradiation angle distribution of the second light beam is denoted by reference numeral S2. . In FIG. 4, the angle distribution and the amount of light to be irradiated are displayed in correspondence with each other so that the angle with a larger amount of light component is brighter and the portion with a smaller amount of light component is darker.

  FIGS. 4B, 4D, and 4F are schematic diagrams showing the relationship between the amount of light and the incident angle in the direction along the a-axis through the origin in the corresponding FIGS. 4A, 4C, and 4E. It is. 4B, 4D, and 4F, the horizontal axis represents the position (angle) on the a-axis in FIGS. 4A, 4C, and 4E, and the vertical axis represents the amount of light.

  As shown in FIGS. 4A and 4B, when the photorefractive element 30 is not used, the first light beam and the second light beam have discrete angular distributions. On the other hand, as shown in FIGS. 4C to 4F, by using the photorefractive element 30, the angular distributions of the first light beam and the second light beam are the same (FIG. 4C). d)) or partially different but substantially the same state (FIGS. 4E and 4F).

  By adjusting the refraction angle by the photorefractive element 30, it is possible to control the angle distribution shown in FIGS. 4C and 4D and the angle distribution shown in FIGS. 4E and 4F. Controlling the angular distribution of the first light beam and the second light beam as shown in FIGS. 4C to 4F has the following advantages.

  First, when the angular distribution of the first light beam and the second light beam is controlled as shown in FIGS. 4C and 4D, the angular distribution of the light incident on the lens array 120 and the lens array 130 shown in FIG. Therefore, the amount of light emitted in a direction not entering the subsequent optical system is reduced, and the optical efficiency is increased.

  Further, when the angular distribution of the first light beam and the second light beam is controlled as shown in FIGS. 4E and 4F, the optical efficiency is lower than the states shown in FIGS. 4C and 4D. The optical efficiency can be increased as compared with the states shown in FIGS.

  Further, when the first light beam and the second light beam are coherent, the state shown in FIGS. 4C and 4D is obtained by controlling the state as shown in FIGS. In comparison, the generation of speckle can be suppressed.

  In general, in a projector using a light source that emits coherent light such as laser light, a speckle pattern called speckle noise generated by interference of coherent light may be visually recognized on a screen. Thereby, the display quality of the projected image is greatly reduced. Therefore, in a projector using a light source that emits coherent light, it is preferable to take measures to suppress a decrease in display quality due to speckle noise.

  The inventor has found that speckle noise is less likely to occur when the illuminance distribution at the exit pupil of the projection optical system of the projector is uniform over a wide range, through separate studies. Further, the illuminance distribution at the exit pupil of the projection optical system of the projector has a correlation with the illuminance distribution of the secondary light source image of the light emitting device 10 formed at the position of the lens array 130, and the illuminance distribution of the secondary light source image. Found that there is a correlation with the angular distribution of the light flux incident on the lens array 120.

  That is, according to the inventor's knowledge, the angular distribution of the light beam incident on the lens array 120 has a correlation with the illuminance distribution in the exit pupil of the projection optical system of the projector. Specifically, the illuminance distribution in the exit pupil can be widened by widening the angular distribution of the light flux incident on the lens array 120. Therefore, speckle noise is reduced by controlling the angular distribution of the first light beam and the second light beam incident on the lens array 120 to be widened as shown in FIGS. be able to.

  From the viewpoint of widening the angular distribution of the light flux incident on the lens array 120 as described above, the first light path is formed between the light refraction element 30 and the integrator, that is, between the light source unit 110 and the lens array 120. A light diffusing element that diffuses the light beam and the second light beam may be disposed. Examples of the light diffusing element include a diffusing plate such as a ground glass and a diffusing film, a diffractive optical element such as a holographic diffuser, and a lens component such as a microlens array. By arranging the light diffusing element, speckle can be further reduced.

  According to the light source device having the above configuration, a light source device with high optical efficiency can be provided. Further, it is possible to provide a projector that can display an image with high brightness using such a light source device.

  In the present embodiment, only the first light beam LB1 is refracted by the photorefractive element 30, but another photorefractive element is arranged on the optical path of the second light beam LB2. The emission directions of the light beam LB1 and the second light beam LB2 may be controlled.

  In the present embodiment, the light emitting device 10 emits the first light beam LB1 and the second light beam LB2, but in addition to this, the third light beam may be emitted. Good. In this case, another light refracting element may be arranged on the optical path of the third light beam to control the emission direction of the third light beam.

  In the present embodiment, the first light emitting surface 11s and the second light emitting surface 12s are arranged on a predetermined plane, and the focal point 20p of the collimator lens 20 is located on the second light emitting surface 12s. However, it is not limited to this. If the focal point 20p of the collimator lens 20 is not positioned on the second light emitting surface, the light beam transmitted through the collimator lens 20 is not completely parallel, but the optical system at the latter stage can be obtained by using a photorefractive element. It is possible to obtain the effect of the present invention to improve the optical efficiency in

  In the present embodiment, the optical axis 20ax of the collimator lens 20 is perpendicular to the light emitting surface, but may be inclined.

  In this embodiment, the fly-eye integrator composed of the lens array 120 and the lens array 130 is used. However, the present invention is not limited to this, and a rod integrator or an integrator having a diffractive structure may be used. . A configuration that does not use an integrator can also be employed.

  In the present embodiment, the first light beam LB1 and the second light beam LB2 have the same wavelength. However, the present invention is not limited to this. For example, the first light beam LB1 has different wavelengths. It is red light, and the second light beam LB2 may be green light. In this case, by applying to a projector employing a color separation optical system, it is possible to provide a projector capable of displaying an image with high optical efficiency and high luminance.

  In this embodiment, the laser light source is used for the light emitting device, but a light source having another configuration may be used.

(Modification)
FIG. 5 is an explanatory diagram showing a modification of the light source unit. 5A is a schematic perspective view of the light source unit 111, and FIG. 5B is a schematic plan view of the vicinity of the photorefractive element included in the light source unit 111. FIG.

  As shown in FIG. 5, the light source unit 111 includes a light emitting device (first light emitting device) 10A, a collimator lens (first collimator lens) 20A on which a plurality of light beams emitted from the light emitting device 10A are incident, A light emitting device (second light emitting device) 10B, a collimator lens (second collimator lens) 20B on which a plurality of light beams emitted from the light emitting device 10B are incident, a light emitting device (third light emitting device) 10C, A collimator lens (third collimator lens) 20C on which a plurality of light beams emitted from the light emitting device 10C are incident. In FIG. 5, a plurality of light emitting devices 10 are arranged in a matrix (3 × 3). A plurality of collimator lenses 20 corresponding to each light emitting device 10 are arranged in a matrix (3 × 3).

  The light emitting device 10A emits a first light beam and a second light beam. In FIG. 5, the principal ray axis of the first light beam emitted from the light emitting device (first light emitting device) 10A is denoted by reference symbol RA1, and the principal ray axis of the second light beam is denoted by reference symbol RA2.

  The light emitting device 10B emits a third light beam and a fourth light beam. The principal ray axis of the third light beam emitted from the light emitting device 10B is indicated by a symbol RA3, and the principal ray axis of the fourth light beam is indicated by a symbol RA4.

  The light emitting device 10C emits a fifth light beam and a sixth light beam. The principal ray axis of the fifth light beam emitted from the light emitting device 10C is indicated by a symbol RA5, and the principal ray axis of the sixth light beam is indicated by a symbol RA5.

  The light emitting device 10A, the light emitting device 10B, and the light emitting device 10C have the same configuration as the light emitting device 10 shown in the above-described embodiment. The first light beam emitted from the light emitting device 10A, the third light beam emitted from the light emitting device 10B, and the fifth light beam emitted from the light emitting device 10C are the first light emitted from the light emitting device 10 in the above-described embodiment. Corresponds to the light beam LB1. Similarly, the second light beam emitted from the light emitting device 10A, the fourth light beam emitted from the light emitting device 10B, and the sixth light beam emitted from the light emitting device 10C are emitted from the light emitting device 10 in the above-described embodiment. Corresponds to the second light beam LB2.

  Further, the collimator lens 20A, the collimator lens 20B, and the collimator lens 20C have the same configuration as the collimator lens 20 shown in the above-described embodiment.

  Furthermore, the relationship between the light emitting device 10A and the collimator lens 20A, the relationship between the light emitting device 10B and the collimator lens 20B, and the relationship between the light emitting device 10C and the collimator lens 20C are as follows. The same configuration as that in the relationship with 20 can be adopted.

  In FIG. 5, an xyz coordinate system is adopted, the matrix directions in which the plurality of light emitting devices 10 are arranged are the x direction and the y direction, respectively, and the normal direction of the light emitting surface of the light emitting device 10 is the z direction.

  The light refracting unit 300 included in the light source unit 111 has an array structure including a plurality of light refracting elements 310 and a connection unit 320 connecting the plurality of light refracting elements 310 to each other. Specifically, the first light beam emitted from the light emitting device 10A and the fifth light beam emitted from the light emitting device 10C are incident, and the light refracting element (first light refracting element) 310A and the light emitting device 10B emit the light. A light refracting element (second light refracting element) 310B on which the third light beam is incident, and a connection portion 320AB that connects the light refracting element 310A and the light refracting element 310B.

  The connection portion 320 is formed using a light-transmitting forming material. As a material for forming the connection part 320, for example, the same material as that of the photorefractive element 310 can be used. By forming the photorefractive element 310 and the connection portion 320 with the same forming material, the formation of the photorefractive portion 300 is facilitated. Of course, the photorefractive element 310 and the connecting portion 320 may be formed of different forming materials.

  As shown in FIG. 5B using the principal ray axis, the second light beam, the fourth light beam, and the sixth light beam emitted from each light emitting device 10 are transmitted through the connection portion 320. Ejected from the light refraction unit 300. Therefore, the light incident surface and the light exit surface of the connection part 320 are preferably parallel to each other so that the second light beam, the fourth light beam, and the sixth light beam are not refracted.

  The photorefractive element 310A is provided across the light emitting device 10A and the light emitting device 10C. The photorefractive element 310A refracts the first light beam emitted from the light emitting device 10A, and forms an angle between the first light beam and the second light beam (the principal ray axis RA1 and the principal ray axis RA2 form each other). The angle θ1) is decreased, and the fifth light beam emitted from the light emitting device 10C is refracted to form angles formed by the fifth light beam and the sixth light beam (the principal ray axis RA5 and the principal ray axis RA6). Is reduced.

  In addition, the photorefractive element 310B refracts the third light beam emitted from the light emitting device 10B, and makes an angle between the third light beam and the fourth light beam (the principal ray axis RA3 and the principal ray axis RA4). Is reduced.

  For example, as illustrated in FIG. 5B, the light refraction unit 300 includes a first light beam, a second light beam, a third light beam, a fourth light beam, a fifth light beam, and a sixth light beam. Are emitted in the same direction.

  In the light source device having the light source unit 111 having such a configuration, the number of components that refract the first light beams emitted from the plurality of light emitting devices 10 can be reduced. Therefore, a light source device with a simplified configuration can be obtained.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such examples. Various shapes, combinations, and the like of the constituent members shown in the above-described examples are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

  In this embodiment, the angle θ formed between the first light beam and the second light beam after passing through the photorefractive element and the speckle are obtained by simulation using illumination design analysis software (LightTools, manufactured by Synopsys). The relationship with the reduction effect was examined.

  In the simulation, a model using 30 light source units 110 shown in FIG. 2 was assumed. Further, assuming that the light emitted from the light source unit 110 enters the projection optical system 600 via the lens array 120, the lens array 130, and the superimposing lens 150 shown in FIG. 1, the illuminance distribution at the exit pupil of the projection optical system 600 is evaluated. did.

  The simulation results are shown in Table 1. In Table 1, “overlapping state” indicates how the angular distribution of the first light beam and the angular distribution of the second light beam overlap. “Overlapping”, “partially overlapping”, and “non-overlapping” correspond to the overlapping states of FIGS. 4C, 4E, and 4A, respectively. The angle θ is reflected in the “overlapping state”. “Uniformity” is relative to the illuminance distribution at the exit pupil when the angular distribution of the first light beam and the angular distribution of the second light beam overlap with each other without using a diffusion plate. Value. The higher the uniformity, the less likely that speckle noise will occur.

  From the above results, it has been found that the uniformity of the first light beam and the second light beam after passing through the photorefractive element is improved and speckle reduction is effective. Further, it has been found that providing a light diffusing element between the integrator and the first photorefractive element can broaden the illuminance distribution in the exit pupil, and thus can enhance the speckle reduction effect.

  DESCRIPTION OF SYMBOLS 10,10A ... Light-emitting device (1st light-emitting device) 10B ... Light-emitting device (2nd light-emitting device), 10C ... Light-emitting device (3rd light-emitting device), 11s ... 1st light emission surface, 12s ... 2nd 20, 20A ... collimator lens (first collimator lens), 20B ... collimator lens (second collimator lens), 20C ... collimator lens (third collimator lens), 20ax ... optical axis, 20p ... focus. , 30, 310A ... Photorefractive element (first photorefractive element), 100, 100B, 100G, 100R ... Light source device, 300 ... Light refracting unit, 310B ... Photorefractive element (second photorefractive element), 310 ... Photorefractive element 320... Connection part, 400R, 400G, 400B... Liquid crystal light valve (light modulation element), 600... Projection optical system, L .. light, LB1 ... first light beam, LB2. PJ ... projector, RA1 ... principal ray axis of first light beam, RA2 ... principal ray axis of second light beam, RA3 ... principal ray axis of third light beam, RA4 ... fourth light Principal ray axis of beam, RA5 ... Principal ray axis of fifth light beam, RA6 ... Principal ray axis of sixth light beam

Claims (11)

A first light emitting device that emits a plurality of light beams including a first light beam and a second light beam;
A first collimator lens on which the plurality of light beams are incident;
A first photorefractive element on which the first light beam transmitted through the first collimator lens is incident,
The second light beam passes through a region outside the first photorefractive element;
The first photorefractive element is configured to reduce an angle formed by the first light beam and the second light beam ;
A second light emitting device for emitting a third light beam and a fourth light beam;
A second collimator lens on which the third light beam and the fourth light beam are incident;
A second photorefractive element on which the third light beam transmitted through the second collimator lens is incident;
A connection portion for connecting the first photorefractive element and the second photorefractive element;
The fourth light beam passes through a region outside the second photorefractive element;
The second photorefractive element is a light source device configured to reduce an angle formed by the third light beam and the fourth light beam .   If the angle formed by the first light beam immediately after passing through the first collimator lens and the second light beam immediately after passing through the first collimator lens is θ, the first photorefractive element The light source device according to claim 1, wherein an angle formed by the first light beam and the second light beam is larger than 0 and smaller than θ. The first light emitting device has a plurality of light emitting surfaces including a first light emitting surface that emits the first light beam and a second light emitting surface that emits the second light beam,
The plurality of light emitting surfaces are arranged on a predetermined plane,
The light source device according to claim 1, wherein a focal point of the first collimator lens is located on the predetermined plane.   The light source device according to claim 3, wherein an optical axis of the first collimator lens is perpendicular to the predetermined plane. An integrator for making the intensity distribution of the light bundle emitted from the first collimator lens uniform;
5. The light source device according to claim 1, wherein the first photorefractive element is disposed on an optical path between the first collimator lens and the integrator. 6.   The light source device according to claim 5, further comprising a light diffusing element between the integrator and the first photorefractive element.   7. The light source device according to claim 1, wherein an optical axis of the first collimator lens coincides with a principal ray axis of the second light beam.   The light source device according to claim 1, wherein the first light beam and the second light beam have the same wavelength. A third light emitting device for emitting a fifth light beam and a sixth light beam;
A third collimator lens on which the fifth light beam and the sixth light beam are incident; and
The fifth light beam transmitted through the third collimator lens is incident on the first photorefractive element,
The sixth light beam passes through a region outside the first photorefractive element;
Said first optical refractive element, the fifth light beam and the sixth light source device according to claim 1, which is configured to reduce the angle in any one of 8 of the light beam . The light emitting device includes a light source device according to any one of claims 1 9 is a laser light source. A light source device according to any one of claims 1 to 10 ,
A light modulation element for modulating light emitted from the light source device;
And a projection optical system that projects the light modulated by the light modulation element.

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