JP2017151145A - Light source device and projection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light source device that can improve a degree of a design freedom or transmittance of a light beam.SOLUTION: A light source device 1 comprises: a transmission side light emitting unit 10 and reflection side light emitting unit 20 that output a light beam, respectively; a light synthesis unit 30 that makes the light beam to be transmitted or reflected in accordance with a polarization direction the incident light beam, and overlaps a plurality of light beams; and a light output detection unit 50 that detects an output of the incident light beam. The transmission side light emitting unit 10 and reflection side light emitting unit 20 are configured to output the light beam inclining with respect to the polarization direction. The light beam reflected by the light synthesis unit 30 of the light beams output from the transmission side light emitting unit 10, and the light beam transmitting the light synthesis unit 30 of the light beams output from the reflection side light emitting unit 20 are configured to be incident upon the light output detection unit 50.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a light source device and a projection device including a plurality of light emitting units that respectively output light beams.

  2. Description of the Related Art In recent years, semiconductor lasers have been actively used regardless of industrial use or consumer use. For example, a projector that projects an image by scanning laser light is known. Such projectors are mounted on a variety of projectors, and vehicle display devices using a vehicle windshield or the like as a screen have been proposed (see, for example, Patent Document 1).

JP2015-56600A

  A vehicle display device described in Patent Document 1 includes a laser light source, a temperature adjustment element that heats the laser light source, temperature information acquisition means that acquires temperature information of the laser light source, and the laser light source itself to heat the temperature adjustment element. When the laser light source is heated and a predetermined condition is determined to be satisfied, temperature control means for normally driving the laser light source is provided, and an image generated by spatial light modulation of the laser light emitted from the laser light source is displayed. doing. In the vehicle display device described above, the laser light is synthesized using the combining means, and a part of the laser light is reflected using the reflective / transmissive film in the direction of the color sensor that detects the intensity of the light. By the way, in a projector or the like, various optical components are used to reflect or transmit laser light. However, considering the miniaturization of the apparatus and the light utilization efficiency, it is desirable to reduce the number of optical components.

  SUMMARY An advantage of some aspects of the invention is that it provides a light source device and a projection device that can improve the degree of freedom in design and the transmittance of a light beam.

  A light source device according to the present invention includes a plurality of light emitting units that respectively output light beams and a plurality of light beams that are transmitted or reflected according to the polarization direction of the incident light beams. A light combining unit that superimposes the light beams and a light output detection unit that detects the output of the incident light beam, wherein the polarization direction of the light beam transmitted through the light combining unit is a transmission direction, When the polarization direction of the light beam reflected by the light combining unit is the reflection direction, the plurality of light emitting units are inclined with respect to the transmission side light emitting unit that outputs a light beam inclined with respect to the transmission direction and with respect to the reflection direction. A reflection side light emitting unit that outputs the light beam, and the light output detection unit includes the light beam reflected by the light combining unit among the light beams output from the transmission side light emitting unit, Reflection side light emission Of the output light beam from a light beam transmitted through the optical coupling section is characterized in that it is configured to be incident.

  In the light source device according to the present invention, the light emitting unit combines a red light emitting element that outputs a red light beam, a green light emitting element that outputs a green light beam, and a blue light emitting element that outputs a blue light beam. It is good also as a structure.

  In the light source device according to the present invention, the light emitting unit is separated from the red light emitting element, the green light emitting element, and the blue light emitting element by a dichroic mirror that transmits or reflects the light beam according to the wavelength of the incident light beam. The output light beams may be combined, and the light beam output from the green light emitting element may be configured to pass through the dichroic mirror.

  The projection device according to the present invention includes the light source device according to the present invention.

  According to the present invention, by making a light beam whose polarization direction is slightly inclined to the light combining unit, a part of the light beam can be incident on the light output detection unit, and the output of the light beam can be easily grasped. be able to. In other words, since the light combining unit divides the output light beam and the light beam toward the light output detection unit, it can be configured without a half mirror on the optical path of the output light beam. The degree of freedom and the light beam transmittance can be improved.

It is a schematic block diagram which shows the outline of the light source device which concerns on 1st Embodiment of this invention. It is a schematic block diagram of the comparative example which shows the conventional light source device. It is explanatory drawing which shows the relationship between the light synthesis part and the polarization direction of a light beam in a comparative example. It is explanatory drawing which shows the relationship between the photosynthesis part in 1st Embodiment of this invention, and the polarization direction of a light beam. It is a schematic block diagram which shows the outline of the light source device which concerns on 2nd Embodiment of this invention.

(First embodiment)
Hereinafter, a light source device according to a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an outline of a light source device according to a first embodiment of the present invention.

  The light source device 1 includes a plurality of light emitting units (a transmission side light emitting unit 10 and a reflection side light emitting unit 20), a light combining unit 30, a light output detecting unit 50, and a MEMS mirror 40, and each unit is housed in a housing. It is said that.

  The light emitting unit includes three light emitting elements (for example, laser diodes) that output a light beam, and two dichroic mirrors that transmit or reflect the light beam according to the wavelength of the incident light beam.

  Specifically, the transmission side light emitting unit 10 includes a first transmission side light emitting element 11, a second transmission side light emitting element 12, a third transmission side light emitting element 13, a first transmission side dichroic mirror 14a, and a second transmission side dichroic mirror. 14b. The first transmission side light emitting element 11 is a red light emitting element that outputs a red light beam (first transmission side light beam LP1). The second transmission side light emitting element 12 is a green light emitting element that outputs a green light beam (second transmission side light beam LP2). The third transmission side light emitting element 13 is a blue light emitting element that outputs a blue light beam (third transmission side light beam LP3). The first transmission side dichroic mirror 14a is disposed in front of the first transmission side light emitting element 11, transmits a red light beam, and reflects green and blue light beams. The second transmission side dichroic mirror 14b is disposed in front of the second transmission side light emitting element 12, and transmits the blue light beam and reflects the green light beam. The third transmission side light emitting element 13 is disposed at a position facing the first transmission side dichroic mirror 14a via the second transmission side dichroic mirror 14b.

  Next, the path of the light beam in the transmission side light emitting unit 10 will be described. The first transmission side light beam LP1 output from the first transmission side light emitting element 11 passes through the first transmission side dichroic mirror 14a. The second transmission side light beam LP2 output from the second transmission side light emitting element 12 is reflected by the second transmission side dichroic mirror 14b and travels toward the first transmission side dichroic mirror 14a. The third transmission side light beam LP3 output from the third transmission side light emitting element 13 passes through the second transmission side dichroic mirror 14b and travels toward the first transmission side dichroic mirror 14a. The first transmission-side light beam LP1, the second transmission-side light beam LP2, and the third transmission-side light beam LP3 pass through the first transmission-side dichroic mirror 14a to the light combining unit 30 as a combined transmission-side combined light beam MLP. Incident.

  The reflection-side light emitting unit 20 has substantially the same configuration as the transmission-side light emitting unit 10 and is configured to enter the light combining unit 30 from a direction different from that of the transmission-side light emitting unit 10. Specifically, the reflection side light emitting unit 20 includes a first reflection side light emitting element 21, a second reflection side light emitting element 22, a third reflection side light emitting element 23, a first reflection side dichroic mirror 24a, and a second reflection side dichroic mirror. 24b. The first reflection-side light emitting element 21 is a red light-emitting element that outputs a red light beam (first reflection-side light beam LS1). The second reflection-side light emitting element 22 is a green light-emitting element that outputs a green light beam (second reflection-side light beam LS2). The third reflection-side light emitting element 23 is a blue light-emitting element that outputs a blue light beam (third reflection-side light beam LS3). The first reflection-side dichroic mirror 24a is disposed in front of the first reflection-side light emitting element 21, transmits a red light beam, and reflects green and blue light beams. The second reflection side dichroic mirror 24b is disposed in front of the second reflection side light emitting element 22, and transmits the blue light beam and reflects the green light beam. Further, the third reflection side light emitting element 23 is disposed at a position facing the first reflection side dichroic mirror 24a via the second reflection side dichroic mirror 24b.

  Next, the path of the light beam in the reflection side light emitting unit 20 will be described. The first reflection-side light beam LS1 output from the first reflection-side light emitting element 21 is transmitted through the first reflection-side dichroic mirror 24a. The second reflection-side light beam LS2 output from the second reflection-side light emitting element 22 is reflected by the second reflection-side dichroic mirror 24b and travels toward the first reflection-side dichroic mirror 24a. Further, the third reflection-side light beam LS3 output from the third reflection-side light emitting element 23 passes through the second reflection-side dichroic mirror 24b and travels toward the first reflection-side dichroic mirror 24a. The second reflection side light beam LS2 and the third reflection side light beam LS3 are reflected by the first reflection side dichroic mirror 24a. As a result, the first reflection-side light beam LS1, the second reflection-side light beam LS2, and the third reflection-side light beam LS3 pass through the first reflection-side dichroic mirror 24a and are combined as a combined reflection-side combined light beam MLS. Incident on the portion 30.

  The light combining unit 30 is a polarization beam splitter, and transmits or reflects the light beam according to the polarization direction of the incident light beam. The transmission-side combined light beam MLP and the reflection-side combined light beam MLS that have entered the light combining unit 30 are combined into a projection light beam TL that is combined and directed toward the MEMS mirror 40, while a detection light beam that is partially directed toward the light output detection unit 50. KL. The relationship between the polarization direction of the transmission-side combined light beam MLP and the reflection-side combined light beam MLS and the light combining unit 30 will be described in detail with reference to FIG. 4 described later.

  The MEMS mirror 40 is a mirror that is driven to rotate, and reflects the projection light beam TL emitted from the light combining unit 30 to irradiate the outside of the housing. The projection light beam TL can be scanned by changing the direction in which the MEMS mirror 40 is driven and reflected.

  The light output detection unit 50 is a sensor that detects the output of the incident detection light beam KL, and includes a photodiode or the like. The detection result of the light output detection unit 50 is fed back to the control of the light emitting unit, whereby the projection light beam TL can be controlled to an appropriate output.

  Next, the structure of the comparative example showing the conventional light source device and the structure of the light source device 1 according to the first embodiment of the present invention will be compared to describe the problems of the conventional structure.

  FIG. 2 is a schematic configuration diagram of a comparative example showing a conventional light source device.

  The comparative example differs from the first embodiment in the arrangement of the MEMS mirror 40 and the light output detection unit 50. Similarly to the first embodiment, the transmission-side combined light beam MLP and the reflection-side combined light beam MLS are incident on the light combining unit 30, but only the projection light beam TL is emitted. The projection light beam TL is incident on the half mirror 60 disposed in front of the light output detection unit 50. The half mirror 60 transmits a part of the incident projection light beam TL and reflects the rest. The projection light beam TL transmitted through the half mirror 60 is incident on the light output detector 50, and the projection light beam TL reflected by the half mirror 60 is incident on the MEMS mirror 40 and scanned. That is, in the comparative example, the light combining unit 30 only combines the transmission-side combined light beam MLP and the reflection-side combined light beam MLS. Therefore, the half mirror 60 is provided to extract the light beam incident on the light output detection unit 50. There is a need. Conventionally, since the configuration is such that the projection light beam TL is incident on the half mirror 60, there are problems such as restrictions on the arrangement of components and an increase in the number of components.

  By the way, in the first embodiment and the comparative example, the polarization directions of the transmission-side combined light beam MLP and the reflection-side combined light beam MLS are different, and will be described in detail with reference to the drawings.

  FIG. 3 is an explanatory diagram illustrating a relationship between the light combining unit and the polarization direction of the light beam in the comparative example.

  FIG. 3 is an enlarged view of the vicinity of the light combining unit 30 in the comparative example shown in FIG. 2, and schematically shows the path of the light beam. The side of the light combining unit 30 is covered with an antireflection film so as not to prevent the transmission-side combined light beam MLP and the reflection-side combined light beam MLS from entering, and a polarization plane 31 is formed inside. The polarization plane 31 is formed of a dielectric multilayer film, transmits a P-polarized component (transmission direction P) of a light beam that is parallel to the polarization plane 31, and is perpendicular to the polarization plane 31. The S deflection component (reflection direction S) of the directed light beam is reflected. In the comparative example, the transmission-side combined light beam MLP has the polarization direction as the transmission direction P, and the reflection-side combined light beam MLS has the polarization direction as the reflection direction S. In the comparative example, when the transmission side combined light beam MLP and the reflection side combined light beam MLS are incident on the polarization plane 31, the transmission side combined light beam MLP transmitted through the polarization plane 31 and the reflection side combination reflected by the polarization plane 31 are combined. The light beam MLS is combined and the projection light beam TL is emitted from the light combining unit 30.

  FIG. 4 is an explanatory diagram showing the relationship between the light combining unit and the polarization direction of the light beam in the first embodiment of the present invention.

  FIG. 4 is an enlarged view of the vicinity of the light combining unit 30 in the first embodiment shown in FIG. 1, and schematically shows the path of the light beam. In the present embodiment, the transmission-side combined light beam MLP has an inclined transmission direction dP in which the polarization direction is inclined with respect to the transmission direction P, and the reflection-side combined light beam MLS has a polarization direction with respect to the reflection direction S. The inclined reflection direction dS is inclined. The angle at which the inclined transmission direction dP is inclined with respect to the transmission direction P and the angle at which the inclined reflection direction dS is inclined with respect to the reflection direction S are the same angle (inclination angle θ). Also good. That is, the transmission-side combined light beam MLP and the reflection-side combined light beam MLS are light beams including a P deflection component and an S deflection component by tilting the polarization direction. The ratio can be adjusted by the inclination angle θ.

  In the present embodiment, the transmission-side combined light beam MLP incident on the light combining unit 30 transmits the light beam corresponding to the P deflection component to become the projection light beam TL, and the light beam corresponding to the S deflection component is reflected. It becomes the detection light beam KL. Further, the reflection-side combined light beam MLS incident on the light combining unit 30 is reflected by the light beam corresponding to the S deflection component to become the projection light beam TL, and the light beam corresponding to the P deflection component is transmitted and detected light beam KL. It becomes. As a result, most of the transmission-side combined light beam MLP and the reflection-side combined light beam MLS are emitted as the projection light beam TL, and a part is emitted as the detection light beam KL.

  As described above, in the light source device 1 of the present embodiment, the polarization direction of the light beam transmitted through the light combining unit 30 is the transmission direction P, and the polarization direction of the light beam reflected by the light combining unit 30 is the reflection direction S. The plurality of light emitting units include a transmission side light emitting unit 10 that outputs a light beam inclined with respect to the transmission direction P and a reflection side light emitting unit that outputs a light beam inclined with respect to the reflection direction S. ing. The light output detection unit 50 includes the light beam reflected from the light combining unit 30 among the light beams (transmission side combined light beam MLP) output from the transmission side light emitting unit 10 and the light output from the reflection side light emitting unit 20. Of the beam (the reflection-side combined light beam MLS), the light beam that has passed through the light combining unit 30 is incident.

  According to this configuration, by making a light beam whose polarization direction is slightly inclined to the light combining unit 30, a part of the light beam can be incident on the light output detection unit 50, and the output of the light beam can be easily performed. I can grasp it. Conventionally, since the light beam is incident on the light output detection unit 50 via the half mirror 60, the transmittance is reduced and the light beam is lost. In contrast, since the light combining unit 30 divides the output light beam TL to be output and the detection light beam KL toward the light output detection unit 50, a half mirror 60 is provided on the optical path of the output light beam. Thus, the degree of freedom in design and the transmittance of the light beam can be improved. That is, by adjusting the polarization direction, it is possible to consolidate both functions of light beam synthesis and extraction in the light synthesis unit 30, which is an effective configuration for reducing optical components.

  In this embodiment, the light emitting unit is a combination of a red light emitting element, a green light emitting element, and a blue light emitting element. By combining three color light beams, the color of the output light beam can be freely set. Can be set.

(Second Embodiment)
Next, a light source device according to a second embodiment of the invention will be described with reference to the drawings.

  FIG. 5 is a schematic configuration diagram showing an outline of a light source device according to the second embodiment of the present invention. In addition, about the component which a function is substantially equal to 1st Embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The second embodiment differs from the first embodiment in the number of light emitting elements. Specifically, each of the transmission side light emitting unit 10 and the reflection side light emitting unit 20 is composed of one light emitting element. Since there is one light emitting element, the dichroic mirror is not provided, but an optical component such as a mirror may be provided as appropriate. The color of the light beam emitted from the light emitting element is not particularly limited, but it is desirable that the color of the transmission side light emitting unit 10 and the reflection side light emitting unit 20 be the same. That is, a light beam having a high light amount can be output by combining light beams of the same color. The light beam emitted from the light emitting element is not limited to visible light, and may be light outside the visible light region such as infrared rays and ultraviolet rays.

  The transmission side light emitting unit 10 emits a transmission side light beam LP whose polarization direction is an inclined transmission direction dP inclined with respect to the transmission direction P, and the reflection side light emitting unit 20 has a polarization direction with respect to the reflection direction S. A reflection side light beam LS having an inclined inclined reflection direction dS is emitted. That is, the transmission side light beam LP corresponds to the transmission side combined light beam MLP shown in FIG. 4, and the reflection side light beam LS corresponds to the reflection side combined light beam MLS shown in FIG. The transmission-side light beam LP and the reflection-side light beam LS are combined by the light combining unit 30, and most of the light is emitted as the projection light beam TL, and part of it is emitted as the detection light beam KL.

(Third embodiment)
Next, a light source device according to a third embodiment of the invention will be described. The third embodiment has substantially the same configuration as that of the first embodiment shown in FIG.

  3rd Embodiment differs in arrangement | positioning of a red light emitting element, a green light emitting element, and a blue light emitting element with respect to 1st Embodiment. Specifically, in the third embodiment, the transmissive side light emitting unit 10 includes a first transmissive side light emitting element 11 as a green light emitting element, a second transmissive side light emitting element 12 as a blue light emitting element, and a third transmissive side light emitting element. The element 13 is a red light emitting element. In the reflection side light emitting unit 20, the first reflection side light emitting element 21 is a green light emitting element, the second reflection side light emitting element 22 is a blue light emitting element, and the third reflection side light emitting element 23 is a red light emitting element. ing.

  That is, the light beams (the first transmission side light beam LP1 and the first reflection side light beam LS1) output from the first transmission side light emitting element 11 and the first reflection side light emitting element 21 which are green light emitting elements are arranged in front. The light is transmitted through the dichroic mirror (the first transmission side dichroic mirror 14 a and the first reflection side dichroic mirror 24 a), and enters the light combining unit 30.

  According to this configuration, since the green light beam is guided to the light combining unit 30 without being reflected, the light utilization efficiency of the green light beam can be improved. By the way, it is known that when humans receive visible light from their eyes, the way they perceive brightness differs depending on the wavelength (color), and the way perceived brightness is expressed by a numerical value called specific luminous efficiency. . The specific luminous sensitivity of the colors used in the present embodiment is in the order of green> red> blue. That is, it is possible to output a light beam that does not give a sense of incongruity to humans by maintaining a high amount of light beam having high human relative visibility.

  It should be noted that the embodiment disclosed herein is illustrative in all respects and does not serve as a basis for limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiment, but is defined based on the description of the scope of claims. Moreover, all the changes within the meaning and range equivalent to a claim are included.

  The light source device according to the present invention can be suitably applied to a projection device such as a projector.

DESCRIPTION OF SYMBOLS 1 Light source device 10 Transmission side light emission part (an example of light emission part)
DESCRIPTION OF SYMBOLS 11 1st transmission side light emitting element 12 2nd transmission side light emitting element 13 3rd transmission side light emitting element 14a 1st transmission side dichroic mirror 14b 2nd transmission side dichroic mirror 20 Reflection side light emission part (an example of light emission part)
DESCRIPTION OF SYMBOLS 21 1st reflection side light emitting element 22 2nd reflection side light emitting element 23 3rd reflection side light emitting element 24a 1st reflection side dichroic mirror 24b 2nd reflection side dichroic mirror 30 Light composition part 40 MEMS mirror 50 Light output detection part dP Tilt transmission direction dS Inclined reflection direction P Transmission direction S Reflection direction

Claims (4)

A plurality of light emitting units each outputting a light beam;
A light combining unit that transmits or reflects the light beams output from the plurality of light emitting units according to the polarization direction of the incident light beam, and superimposes the plurality of light beams;
A light source device comprising a light output detector for detecting the output of an incident light beam,
When the polarization direction of the light beam transmitted through the light combining unit is the transmission direction, and the polarization direction of the light beam reflected by the light combining unit is the reflection direction,
The plurality of light emitting units include a transmission side light emitting unit that outputs a light beam inclined with respect to the transmission direction, and a reflection side light emitting unit that outputs a light beam inclined with respect to the reflection direction.
The light output detection unit includes: a light beam reflected from the light combining unit among light beams output from the transmission side light emitting unit; and a light combining unit included in the light beam output from the reflection side light emitting unit. A light source device characterized in that a transmitted light beam is incident thereon. The light source device according to claim 1,
The light emitting unit is configured by combining a red light emitting element that outputs a red light beam, a green light emitting element that outputs a green light beam, and a blue light emitting element that outputs a blue light beam. A light source device. The light source device according to claim 2,
The light emitting unit synthesizes the light beams output from the red light emitting element, the green light emitting element, and the blue light emitting element by a dichroic mirror that transmits or reflects the light beam according to the wavelength of the incident light beam. With the configuration,
The light beam output from the green light emitting element is transmitted through the dichroic mirror.   The projection apparatus provided with the light source device as described in any one of Claim 1- Claim 3.

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