JP2019101200A - Light source device and projection type video display device - Google Patents

Abstract

To provide a light source device which can be miniaturized without decreasing the use efficiency of light.SOLUTION: The light source device includes a first light source unit which comprises a plurality of laser light sources arranged so as to emit light in a first direction, a first condenser lens which is arranged on the emission side of the light emitted from the first light source unit, a second light source unit which comprises a plurality of laser light sources arranged so as to emit the light in a second direction orthogonal to the direction of the light emitted from the first light source unit, a second condenser lens which is arranged on the emission side of the light emitted from the second light source unit, and a light synthesis member which has a light reflection part and a slit-like light transmission part. The light synthesis member is arranged so that the light emitted while converging from the first condenser lens is transmitted through the light transmission part and the light emitted while converging from the second condenser lens is reflected by the light reflection part in the same direction as the emission direction of the light transmitted through the light transmission part.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a light source device using a laser light source, and a projection type video display using the same.

  In Patent Document 1, a first light source unit including a plurality of laser elements for emitting excitation light for exciting a phosphor, and a second light source unit for emitting excitation light from a position different from the first light source unit And a projector having a light combining unit that combines the light source and the light source.

JP, 2013-114980, A

  The present disclosure provides a light source device and a projection-type image display device that suppress an increase in the size of the light source unit without reducing the utilization efficiency of light when a plurality of light source units in which a plurality of laser light sources are bundled are used.

  The light source device in the present disclosure includes a first light source unit including a plurality of laser light sources arranged so as to emit light in a first direction, and a light emitting device disposed on the light emitting side of light emitted from the first light source unit. A second light source unit comprising a first condenser lens and a plurality of laser light sources arranged to emit light in a second direction orthogonal to the direction of light emitted from the first light source unit And a light combining member having a second condenser lens disposed on the light emission side of the light emitted from the second light source unit, a light reflecting portion, and a slit-like light transmitting portion, The light emitted from the first condensing lens is transmitted through the light transmitting portion while the light emitted from the second condensing lens is transmitted through the light transmitting portion. The light reflecting portion is arranged to reflect in the same direction.

  Even when a plurality of laser light sources are used, the light source device in the present disclosure is effective for suppressing the enlargement without reducing the light utilization efficiency of the light source device.

A diagram showing a configuration of a light source device according to an embodiment Image of phosphor wheel used in light source device in the embodiment The figure which shows the relationship of the wavelength of the dichroic mirror used with the light source device in embodiment, and the transmittance | permeability The figure which shows the structure of the projection type video display apparatus which mounts the light source device in embodiment. The figure which shows the photosynthesis member in embodiment

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

  It should be noted that the attached drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and they are not intended to limit the claimed subject matter.

Embodiment
Hereinafter, an embodiment will be described using FIGS. 1 to 5.

[1. Configuration of light source device]
FIG. 1 is a view for explaining the configuration of an optical system of a light source device 1 using a phosphor wheel device 60. As shown in FIG. For convenience of the following description, an XYZ orthogonal coordinate system shown in FIG. 1 is used in FIG.

  First, the light source device 1 will be described. The light source device 1 includes a first light source unit 10 and a second light source unit 20. The first light source unit 10 includes a plurality of laser light sources 11 as excitation light sources, and a collimator lens 12 disposed on the emission side of the laser light sources 11. Similar to the first light source unit 10, the second light source unit 20 also includes a plurality of laser light sources 21 as excitation light sources, and a collimating lens 22 disposed on the emission side of the laser light sources 21. The laser light sources 21 and 22 are blue semiconductor lasers that emit blue colored light with a wavelength width of 447 nm to 462 nm and emit linearly polarized light, and are configured by a plurality of semiconductor lasers to realize a high-intensity illumination device. It is done. In FIG. 1, although the first light source unit 10 and the second light source unit 20 are illustrated by exemplarily juxtaposing four blue semiconductor lasers, a plurality of blue semiconductor lasers are perpendicular to the paper in the form of a matrix. Placed on a flat surface. In FIG. 1, each blue semiconductor laser is exemplarily arranged so as to be S-polarized light in which the polarization direction of the emitted light is the Y-axis direction.

  The laser light which is the excitation light emitted from the laser light source 11 of the first light source unit 10 is collimated by the corresponding collimating lens 12. The light emitted from the collimating lens 12 is substantially parallel light.

  The first condensing lens 100 is disposed on the emission side of the laser light emitted from the first light source unit 10, and the collimated light emitted from the collimating lens 12 is entirely obtained by the first condensing lens 100. The luminous flux is collected.

  On the other hand, laser light which is excitation light emitted from the laser light source 21 of the second light source unit 20 is collimated by the corresponding collimating lens 22. The light emitted from the collimating lens 22 is substantially parallel light.

  The second condensing lens 200 is disposed on the emission side of the laser light emitted from the second light source unit 20, and the collimated light emitted from the collimating lens 22 is entirely obtained by the second condensing lens 200. The luminous flux is collected.

  The light combining member 30 is disposed to be inclined with respect to the optical axis of the emitted light of both the first light source unit 10 and the second light source unit 20. FIG. 5 is a view for explaining the structure of the light combining member 30. The light combining member 30 is a light reflecting portion 35 formed by forming a reflective film on one surface of a transparent glass plate (hatched area). The first to fourth light transmitting portions 31 to 34 having rectangular slits are formed, and in these light transmitting portions, in place of the reflective film, anti-reflection films are formed on both sides of the glass plate Become. The slit width of the first light transmitting portion 31 in the lateral direction is a1, the slit width of the second light transmitting portion 32 in the lateral direction is a2, and the slit width of the third light transmitting portion 33 in the lateral direction is a3. The slit width in the short direction of the fourth light transmitting portion 34 is a3. The first to fourth light transmitting portions are disposed in the order of the first to fourth light transmitting portions in the direction from the position close to the first light collecting lens or the second light collecting lens, The size of the slit width has a relationship of a1> a2> a3> a4. In this embodiment, the number N of light transmission parts is N = 4, but may be more than that, for example, five. In that case, the size of each slit width is a1> a2> It becomes the relationship of a3> a4> a5.

  As shown in FIG. 1, the light of each of the laser light sources 11 travels toward the light combining member 30 while being condensed by the first condensing lens 100. The laser light of each of the laser light sources emitted from the first condenser lens 100 passes through the first to fourth light transmitting portions 31 to 34 of the light combining member 30 while being condensed, and enters the lens 40. The lens 40 substantially collimates the collected light.

  The light of each laser light source 21 travels toward the light combining member 30 while being condensed by the second condenser lens 200. The laser light of each of the laser light sources 21 emitted from the second condenser lens 200 is reflected by the light reflecting portion 35 of the light combining member 30 on the way of condensing and is incident on the lens 40. The lens 40 substantially collimates the collected light.

  As described above, the light combining member 30 transmits all the light (light flux) emitted while being converged so as to be condensed from the first condensing lens 100 through the first to fourth light transmitting portions 31 to 34, In order to collect light from the second condenser lens 200, the light reflecting portion 35 is in the same direction as the light emitting direction of light (light flux) emitted while being converged and transmitted through the first to fourth light transmitting portions. It is arranged to reflect.

  The light collected by the first condensing lens 100 is the light transmitted through the first light transmitting part 31 near the first condensing lens 100 among the light transmitting parts of the light combining member 30 disposed at an angle. Since the diameter of the light flux of the collected light is large, the slit width of the light transmitting portion is increased. On the other hand, the light transmitted through the fourth light transmitting portion 34 located at a position far from the first condenser lens 100 has a smaller diameter of the light flux of the collected light, so the fourth light transmitting portion 34 It can be made smaller.

  Also in the light reflecting portion 35, the same consideration is made, and the width of the reflecting portion between the first light transmitting portion 31 and the second light transmitting portion 32, the second light transmitting portion 32 and the third light The width of the reflecting portion between the transmitting portions 33, the width of the reflecting portion between the third light transmitting portion 33 and the fourth light transmitting portion 34, and the end portions of the fourth light transmitting portion 34 and the light combining member 30 The width between the two is set to be large enough to reflect all the advancing light flux while converging with the second condenser lens.

  As described above, in the first light source unit 10, the plurality of laser light sources 11 are disposed such that laser light is emitted in the -X direction which is the first direction, and the second light source unit 20 is the first direction. The plurality of laser light sources 21 are disposed such that laser light is emitted in the Z direction, which is a second direction orthogonal to the first direction.

  The light emitted from the first laser light source 11 and the second laser light source 21 and combined by the light combining member 30 and made approximately collimated by the lens 40 passes through the diffusion plate 41 and is made to a predetermined value with respect to the X axis. The light is irradiated to the quarter-wave plate 42 disposed at an angle of rotation.

  Thus, the quarter-wave plate 42 emits incident light as elliptically polarized light by adjusting the angular arrangement of the optical axis which is the X-axis. In other words, the quarter-wave plate 42 converts the polarization state so that the incident light has a predetermined ratio (for example, the intensity of the S polarization component is 80% and the intensity of the P polarization component is 20%). To emit.

  The diffusion plate 105 is flat glass, and a diffusion surface to which fine asperities are formed is formed on one side. The light transmitted through the quarter-wave plate 42 is incident on the dichroic mirror 50 disposed at an angle of approximately 45 degrees with respect to the optical axis.

  The spectral transmittance of the dichroic mirror 50 is shown in FIG. The dichroic mirror 50 is characterized in that the wavelength at which the transmittance is 50% is 465 nm for S-polarized light and 442 nm for P-polarized light, and blue light is polarized by transmitting or reflecting the dichroic mirror 50 according to this characteristic. It is separated. Specifically, the S-polarization component of blue light is reflected by the dichroic mirror, and the P-polarization component is transmitted through the dichroic mirror. The dichroic mirror 50 has a characteristic of transmitting color light containing green and red components at 96% or more.

  Of the laser light incident on the dichroic mirror 50 in the -X direction in the figure, the S-polarized light component which is one of the linearly polarized light is reflected by the dichroic mirror 50 and emitted in the -Z direction in the figure, and the other linearly polarized light The P-polarization component which is the light is transmitted through the dichroic mirror 50 and is emitted in the -X direction in the drawing. The laser beam emitted in the −Z direction is condensed by the lens 70 and the lens 71, and excites the phosphor formed in the phosphor wheel device 60.

  As shown in the side view (a) of FIG. 2, the phosphor wheel device 60 is composed of a motor 61 and a rotating base 62 made of a disk-shaped plate that is rotationally driven about the rotation axis of the motor 61. Be done.

  As shown in the front view (b) of FIG. 2, the rotary base 62 is yellow with a predetermined width W inside and outside of the circumference on a circumference separated by a distance R1 from the rotation axis A of the phosphor wheel as shown in FIG. A phosphor portion 63 is formed. The surface of the rotary base 62 on which the yellow phosphor portion 63 is formed is processed to have a reflective surface.

  When the laser light from the first and second laser light source units 10 and 21 is condensed on the yellow phosphor portion 63 of the phosphor wheel device 60, the yellow phosphor portion 63 is excited and contains green and red color light Emit yellow light.

  Returning to FIG. 1, the yellow light obtained by the phosphor wheel device 60 is emitted from the phosphor wheel device 15 in the + Z direction. The fluorescent light emitted in the −Z direction by the yellow phosphor portion 63 is reflected by the reflection surface of the rotating base 62 and emitted in the + Z direction. The yellow light is non-polarized light and is collimated by the lenses 70 and 71 and transmitted through the dichroic mirror 50.

  On the other hand, the P polarization of the blue light of the blue semiconductor laser that has passed through the dichroic mirror 50 is collected by the lens 80 and transmitted through the quarter wavelength plate 91 to become circularly polarized light. The light is reflected by the reflecting mirror 92 and transmitted through the quarter-wave plate 91 again to become S-polarized light, condensed by the lens 80 to become substantially parallel light, reflected by the dichroic mirror 50, and emitted in the Z direction Ru.

  Thus, the yellow light (light of green and red components) from the phosphor wheel device 60 and the blue light are combined by the dichroic mirror 50 and emitted as white light.

[2. Configuration of Projection Display Device]
FIG. 4 shows a projection type video display using white light emitted from the light source device 1. White light emitted from the light source device 1 is incident on a first lens array plate 301 composed of a plurality of lens elements. The luminous flux incident on the first lens array plate 301 is divided into a large number of luminous fluxes. The divided multiple light fluxes converge on a second lens array plate 302 composed of a plurality of lenses. The lens elements of the first lens array plate 301 have an opening shape similar to that of the liquid crystal panels 311, 312, and 313. The focal lengths of the lens elements of the second lens array plate 302 are determined such that the first lens array plate 301 and the liquid crystal panels 311, 312, and 313 have a substantially conjugate relationship. The light emitted from the second lens array plate 302 enters the polarization conversion element 303. The polarization conversion element 303 is composed of a polarization separation prism and a half wave plate, and converts natural light from a light source into light of one polarization direction (S polarization). Since fluorescent light is natural light, natural light is polarization-converted in one polarization direction, but blue light is s-polarized and thus polarization is not converted. The light from the polarization conversion element 303 is incident on the superimposing lens 304. The superimposing lens 304 is a lens for superposing and illuminating the light emitted from each lens element of the second lens array plate 302 on the liquid crystal panels 311, 312, and 313. The first lens array plate 301, the second lens array plate 302, the polarization conversion element 303, and the superimposing lens 304 form an illumination optical system that condenses the light from the light source and illuminates the area to be illuminated.

  The light from the superposing lens 304 is separated into blue, green, and red light by the blue reflecting dichroic mirror 305 and the green reflecting dichroic mirror 306, which are color separation means. The green light passes through the field lens 307 and the incident side polarizing plate 308, and enters the liquid crystal panel 311. The blue light is reflected by the reflection mirror 318, passes through the field lens 319 and the incident side polarizing plate 310, and enters the liquid crystal panel 313. The red color light is transmitted, refracted and reflected by the relay lenses 320 and 322 and the reflection mirrors 321 and 323, transmitted through the field lens 324 and the incident side polarizing plate 309, and enters the liquid crystal panel 312.

  The three liquid crystal panels 311, 312, 313 change the polarization state of the incident light by controlling the voltage applied to the pixels according to the video signal, and the transmission axes are orthogonal to both sides of the respective liquid crystal panels 311, 312, 313 The respective incident side polarizers 308, 309, 310 and the emission side polarizers 314, 315, 316 arranged as described above are combined to modulate light to form a green, blue, red image. Each color light transmitted through the output side polarizing plates 314, 315, and 316 is reflected by the color combining prism 317, and each color light of red and blue is reflected by the dichroic mirror of red reflection and the dichroic mirror of blue reflection, respectively. It enters the projection lens 325 as image light which is an image formed by the liquid crystal panel. The light incident on the projection lens 325 is enlarged and projected onto a screen (not shown).

[3. Effect etc]
As described above, in the present embodiment, the size of the transmission portion is between the first condensing lens 100 for condensing light and the second condensing lens 200 and the lens 40 for approximately collimating light. By arranging the light combining member 30 different from each other, the enlargement of the light source device can be suppressed without reducing the light utilization efficiency.

(Other embodiments)
As described above, the embodiment has been described as an example of the technology disclosed in the present application. However, the technology in the present disclosure is not limited to this, and can be applied to embodiments in which changes, replacements, additions, omissions, and the like have been made. Moreover, it is also possible to combine each component demonstrated by the said embodiment, and to set it as a new embodiment.

  For example, the material of the base forming the light combining member 30 is not limited to a glass plate, and for example, a hole may be opened in an aluminum plate to open a light transmitting portion, and a reflective film may be formed on one surface.

  The present disclosure is applicable to a projection type video display device such as a light source device or a projector.

DESCRIPTION OF SYMBOLS 1 light source device 10 1st light source unit 11, 21 laser light source 12, 22 collimate lens 20 2nd light source unit 30 light combining member 31 1st light transmission part 32 2nd light transmission part 33 3rd light transmission part 34 Fourth light transmitting portion 35 Light reflecting portion 40 Lens 41 Diffusion plate 42, 91 Quarter wave plate 50 Dichroic mirror 61 Motor 62 Rotation base material 63 Yellow phosphor portion 70, 71, 80 Lens 92 Reflection mirror 100 First Condenser lens 105 Diffusion plate 200 Second condenser lens 301 First lens array plate 302 Second lens array plate 303 Polarization conversion element 304 Superposing lens 305, 306 Dichroic mirror 307, 319, 324 Field lens 308, 309, 310 Incident side polarizing plates 311, 312, 313 Liquid crystal panels 314, 315, 316 Morphism side polarization plate 317 color combining prism 318,321,323 reflecting mirror 320, 322 relay lens 325 a projection lens

Claims (4)

A first light source unit comprising a plurality of laser light sources arranged to emit light in a first direction;
A first condenser lens disposed on an emission side of light emitted from the first light source unit;
A second light source unit comprising a plurality of laser light sources arranged to emit light in a second direction orthogonal to the direction of light emitted from the first light source unit;
A second condenser lens disposed on an emission side of the light emitted from the second light source unit;
A light combining member having a light reflecting portion and a slit-like light transmitting portion;
The light combining member is configured such that light emitted while converging from the first condensing lens is transmitted through the light transmitting portion, and light emitted while converging from the second condensing lens is the light transmitting portion The light source device is disposed so as to be reflected by the light reflecting portion in the same direction as the emitting direction of light passing through the light source.   The light source device according to claim 1, wherein the light combining member is disposed to be inclined with respect to both the first light source unit and the second light source unit.   The slit width of the light transmitting portion of the light combining member is a1, a2 toward a position farther from a position closer to the first focusing lens or the second focusing lens in which the light combining member is disposed. The light source device according to claim 1, wherein the size of the slit width of the light transmitting portion is a1> a2> a3> a4> a... AN, where a3, a4,.   The projection type video display apparatus provided with the light source device in any one of Claims 1-3.

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