JP2014174442A - Illumination light source device and projection device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination light source device and a projection device in which, when power of excitation light is increased, power of fluorescent light emitted from a phosphor can be increased in accordance with the power of the excitation light.SOLUTION: The illumination light source device includes: laser light emitting diodes 22N1 to 22N3 which emit blue laser light as excitation light at a prescribed wavelength; a phosphor 32 which receives the blue laser light emitted from the laser light emitting diodes 22N1 to 22N3 to emit green light at a wavelength different from that of blue light; and a birefringence member 25 which is arranged between the laser light emitting diodes 22N1 to 22N3 and the phosphor and branches an optical path of the laser light into at least two first and second optical paths. A position in which ordinary rays passing the first optical path branched by the birefringence member 25, out of the laser light emitted from the laser light emitting diodes 22N1 to 22N3 impinge on the phosphor 32 and a position in which extraordinary rays passing the second optical path impinge on the phosphor 32 are different from each other.

Description

  The present invention relates to an illumination light source device having an excitation light source that emits excitation light, and a projection device including the illumination light source device.

  2. Description of the Related Art Conventionally, there has been known a projector that irradiates a fluorescent material with excitation light to emit fluorescent light from the fluorescent material and uses the fluorescent light as projection light for the projector (see Patent Document 1).

  Such a projector includes a first light source that emits blue light, a fluorescent layer that emits green light when irradiated with blue light from the first light source, and a fluorescent layer that diffuses and transmits the blue light. A wheel, a second light source that emits red light, a dichroic mirror that transmits blue light and green light and reflects red light, a motor that rotates a fluorescent wheel, and the like are provided.

  The fluorescent wheel is rotated by a motor, and the blue light emitted from the first light source is irradiated on the fluorescent material layer of the fluorescent wheel to emit green light, and this green light is transmitted through the dichroic mirror and guided. Introduced into the optical device.

  When the irradiation position of the blue light emitted from the first light source moves from the phosphor layer to the diffusion layer due to the rotation of the fluorescent wheel, the blue light passes through the diffusion layer and reaches the dichroic mirror and is transmitted therethrough. To be introduced.

Furthermore, when the irradiation position of the blue light deviates from the diffusion layer due to the rotation of the fluorescent wheel, the first light source is turned off and the second light source is turned on, and red light is emitted from the second light source. Is reflected by the dichroic mirror and introduced into the light guide device.
In this manner, green light, blue light, and red light are sequentially introduced into the light guide device, and a color image is generated on the screen by time-division display of light from the DMD that is the display element of the projector.

  In such a projector, blue light emitted from the first light source is used as excitation light, and high-power green light can be obtained from the phosphor layer by the excitation light.

  However, due to the characteristics of the phosphor, there is a problem that even if the power of the excitation light is increased to a predetermined level or higher, the power of the fluorescent light emitted from the phosphor cannot be increased according to the power.

  An object of the present invention is to provide an illumination light source device capable of increasing the power of fluorescent light emitted from a phosphor according to the power of the excitation light even when the power of the excitation light is increased to a predetermined level or higher, and a projection provided with the illumination light source device. To provide an apparatus.

The invention of claim 1 comprises an excitation light source that emits excitation light of a predetermined wavelength;
A wavelength conversion member that receives excitation light emitted by the excitation light source and emits light having a wavelength different from the predetermined wavelength;
An optical path branching unit that is disposed between the excitation light source and the wavelength conversion member and branches the optical path of the excitation light into at least two first optical paths and a second optical path;
Of the excitation light emitted from the excitation light source, the position where the first excitation light passing through the first optical path branched by the optical path branching unit and the second excitation light passing through the second optical path are incident on the wavelength conversion member Are different.

  According to this invention, even if the power of excitation light is increased to a predetermined level or higher, the power of fluorescent light emitted from the phosphor can be increased according to the power.

It is explanatory drawing which shows the principle of the illumination light source device which concerns on this invention. It is explanatory drawing which shows the principle of the illumination light source device of another example. The graph of the intensity distribution of the spot light formed on a fluorescent substance is shown. The graph of the intensity distribution of the spot light formed on a fluorescent substance at the time of arrange | positioning a birefringent member is shown. It is an optical arrangement | positioning figure which shows the structure of the projection apparatus which concerns on this invention. It is an optical arrangement | positioning figure which shows the structure of the illumination light source device provided in the projection apparatus shown in FIG. It is explanatory drawing which showed the fluorescent substance formed on the board | substrate. (A) is explanatory drawing which showed arrangement | positioning of a laser light emitting diode, (B) is explanatory drawing which showed the polarization direction which behaves as an ordinary ray of a birefringent member, and the polarization direction which acts as an extraordinary ray. It is explanatory drawing which showed the conventional synthetic | combination spot light. It is explanatory drawing which showed the synthetic | combination spot light at the time of using a birefringent member. It is explanatory drawing which showed the sequence direction of the laser light emitting diode of 2nd Example. It is explanatory drawing which showed the polarization direction of the laser light emitting diode of 3rd Example. It is explanatory drawing which showed the arrangement | positioning relationship between a laser light emitting diode and a birefringent member. It is explanatory drawing of 4th Example. It is explanatory drawing which showed rotation of the birefringent member with respect to the polarization direction of a laser light emitting diode. It is explanatory drawing which showed 5th Example. (A) is explanatory drawing which showed the spotlight of the ordinary ray component with respect to a birefringent member, the extraordinary ray component, and the polarization direction of the spotlight, (B) rotated the birefringent member 45 degree | times counterclockwise. (C) Spot light when the birefringent member is rotated 90 degrees counterclockwise, and the polarization direction of the spot light It is explanatory drawing. It is explanatory drawing which showed 6th Example.

  Hereinafter, an illumination light source device according to the present invention and an embodiment that is an embodiment of a projection device including the illumination light source device will be described with reference to the drawings.

[Principle]
FIG. 1 shows the principle of the present invention. In FIG. 1, 1 is a semiconductor laser element (excitation light source), 2 is a coupling lens for condensing laser light emitted from the semiconductor laser element 1, 3 is a birefringent member (optical path branching means), and 4 is a phosphor ( (Wavelength conversion member) 5 is a disk provided with a phosphor 4.
Laser light emitted from the semiconductor laser element 1 is condensed by the coupling lens 2 through the birefringent member 3 and is condensed on the phosphor 4 in the form of spot light.
The laser beam L1 collected by the coupling lens 2 is separated into an ordinary ray L2 and an extraordinary ray L3 that are characteristic of the birefringent member 3, and passes through a parallel plate having a certain thickness due to a difference in refractive index. By doing so, the ordinary ray L2 and the extraordinary ray L3 are shifted by a certain amount.
In other words, the optical path of the laser light can be separated into two, the first optical path and the second optical path. Here, the first optical path is shown as an ordinary ray L2 that does not shift, and the extraordinary ray L3 that shifts the second optical path is shown in FIG.
The ordinary ray L2 and the extraordinary ray L3 form a spot on the phosphor 4 at a position shifted by the distance d.
With such an action of the birefringent member 3, it is possible to obtain two spots although there is only one light source. Naturally, since one spot is separated into two before shifting, the irradiation power is dispersed. Hereinafter, the first optical path will be described as the optical path of the ordinary light beam L2, and the second optical path will be described as the optical path of the extraordinary light beam L3.
The component ratio between the extraordinary ray and the ordinary ray is approximately 50:50 by the birefringent member 3 in the case of an LED or lamp light source that is non-polarized light, but has a polarization dependency like laser light. The light source needs to pay attention to the polarization direction of the light source. In other words, whether the light beam that passes through the birefringent member is treated as an ordinary ray or an extraordinary ray is determined by the relative relationship between the polarization direction of the laser light and the crystal axis of the birefringent member. Accordingly, it is necessary to rotate the birefringent member to obtain an ordinary ray component and an extraordinary ray component.
In FIG. 1, the semiconductor laser element 1 is arranged so that the Y-axis direction is P-polarized light. When the birefringent member 3 is arranged in a direction in which the direction rotated about 45 degrees about the X axis (XY direction) is treated as an ordinary ray, the laser beam is divided into an ordinary ray and an extraordinary ray with an equal intensity ratio. can do.
FIG. 2 shows an example in which a birefringent member 3 is disposed between the semiconductor laser element 1 and the coupling lens 2. Also in this case, the polarization direction of the semiconductor laser element 1 and the direction of the crystal axis of the birefringent member 3 can be arbitrarily changed. As in FIG. Can be divided into two. That is, as shown in FIG. 2, the optical path of the ordinary ray L2 and the extraordinary ray L3 can be shifted to form a spot on the phosphor 4 at a position shifted by the distance d.
FIG. 3A shows a graph G1 of the intensity distribution of spot light formed on the phosphor 4 when the birefringent member 3 is not disposed.
FIG. 3B shows graphs G2 and G3 of the intensity distribution of the spot light formed on the phosphor 4 when the birefringent member 3 is arranged.
As shown in FIG. 3A, assuming that the intensity of the center position of the spot light formed on the phosphor 4 when the birefringent member 3 is not disposed is “1”, in FIG. Is 50:50, the intensity at the center position of the intensity distribution of the spot light separated into two becomes 1/2. The intensity distributions of the two separated spot lights are graphs G2 and G3 that are separated from each other by a distance d.
Since two separate spot lights are irradiated on the phosphor 4, the light having the intensity obtained by synthesizing the two spot lights is irradiated, and a graph G4 indicating the intensity distribution is a graph G2 + G3. The maximum intensity is 1/2. Here, the shifted distance d shows graphs G2 to G4 when the spot light intensity is the same as the spot light diameter at which the intensity of the spot light is ½, but even with a slight shift amount that is 90% of the peak intensity. It has the effect of reducing the maximum strength.
Further, when a point light source such as the semiconductor laser element 1 is used, the diameter of the spot light can be reduced on the phosphor 4, so that the effect of reducing the irradiation power density by the birefringent member 3 is enhanced.
In general, assuming that the refractive index of ordinary light of the birefringent member 3 is no, the refractive index of extraordinary light is ne, and the thickness of the birefringent member 3 is t, the amount of shift of the light of polarized light can be expressed by the following equation: The optical axis is separated by d.

d = (ne ² −no ² ) / (ne ² + no ² ) × t
As the birefringent material, calcite, quartz, sapphire and the like can be raised, and the birefringent material is selected in consideration of the transmittance and the thickness for obtaining a desired shift amount.
For example, taking quartz as an example of a typical birefringent material, since the refractive index no of the ordinary ray is 1.55324 and the refractive index ne of the extraordinary ray is 1.556266 at a wavelength of 442 nm, the shift amount is set to 0.5. In order to obtain about 1 mm, the thickness t of the birefringent member 3 may be t = 17 mm.
Calcite is suitable as a material having high birefringence characteristics. This calcite has the same wavelength around 450 nm, the refractive index of ordinary light no = 1.67, the refractive index of extraordinary light ne = 1.485, and the difference between them is large, and a large shift amount is obtained. In order to obtain such a shift amount, a thickness of the birefringent member 3 of about 0.85 mm is sufficient. If the shift amount is required to be about 0.5 mm, the thickness of the birefringent member 3 may be set to 4.3 mm.
Although the birefringent member has been described as an example of the optical path branching means, a liquid crystal element may be used, and any member may be used as long as it has a function of dividing the optical path into two at the same time.
[First embodiment]
The projection device 10 shown in FIG. 4 includes an illumination light source device 20 that emits green fluorescence, a blue light source device 40 that emits blue light, a red light source device 50 that emits red light, and an image forming element (DMD) 60. The green light of the illumination light source device 20, the blue light of the blue light source device 40, and the red light of the red light source device 50 are collected and reflected by the illumination optical system 70 that illuminates the image forming element 60 and the image forming element 60. A projection optical system 80 that projects the reflected light toward a screen (not shown) and a control device 90 is provided.

  The control device 90 drives each light source of the image forming element 60, the illumination light source device 20, the blue light source device 40, and the red light source device 50 based on the image information input from the image information output device 92 via the image input interface 91. The devices 35, 41 and 51 are controlled.

The image forming element 60 performs on / off control of light in units of pixels according to image information to form a color image for each RGB component in a time-sharing manner, and outputs only light of the color image color to the projection optical system 80. It is designed to reflect.
[Illumination light source device]
As shown in FIG. 5, the illumination light source device 20 includes nine light emitting diodes (semiconductor laser elements) 22N1 to 22N9 which are nine excitation light sources positioned and attached to a holder 21 (see FIG. 6A). ), Coupling lenses 23R1 to 23R9 arranged in front of the respective laser light emitting diodes 22N1 to 22N9, a condenser lens 24, a birefringent member (optical path branching means) 25, and transmits blue light and reflects green light. A dichroic mirror 26 and a fluorescent device 30 are provided.

  In FIG. 5, 27 is a heat sink, and 28 is a lens holder for positioning and holding the coupling lenses 23R1 to 23R9.

  The laser light emitting diodes 22N1 to 22N9 are arranged in a matrix of 3 columns and 3 rows as shown in FIG. 6A, and generate laser light (excitation light) having a blue wavelength in the vicinity of 450 nm. Further, the laser light emitting diodes 22N1 to 22N9 are arranged so that the polarization direction of the laser light emitted from the laser light emitting diodes 22N1 to 22N9 is an arrow direction inclined by 45 degrees with respect to the horizontal direction (X direction).

  In the birefringent member 25, as shown in FIG. 6B, the polarization direction in which the incident light beam is separated and behaves as an ordinary ray is the Y direction, and the polarization direction in which the other separated light beam behaves as an extraordinary ray is the X direction. Thus, the crystal axes are selected and arranged. With respect to the Y direction of the birefringent member 25, the polarization directions of the laser light emitting diodes 22N1 to 22N9 are 45 degrees.

The condensing lens 24 condenses the laser light emitted from the laser light emitting diodes 22N1 to 22N9 on a phosphor 32 described later.
[Fluorescent device]
As shown in FIG. 5, the fluorescent device 30 includes a circular substrate 31 that is rotated by a motor M, and a phosphor (wavelength conversion member) 32 provided on the substrate 31. The motor M is controlled by the control device 90.
The phosphor 32 is formed in a ring shape having a predetermined width W as shown in FIG. 5A, and emits green fluorescence when irradiated with blue light. Further, the phosphor 32 is disposed at a position near the focal length of the condenser lens 24.
[Blue light source device]
As shown in FIG. 4, the blue light source device 40 includes a light emitting diode 42 that emits blue light, a condenser lens 43 that collects the blue light emitted from the light emitting diode 42, and a blue light that reflects blue light and emits green light. A dichroic mirror 44 is provided. A light source driving device 41 drives the light emitting diode 42.
[Red light source device]
The red light source device 50 includes a light emitting diode 52 that emits red light, a condensing lens 53 that collects red light emitted from the light emitting diode 52, and a dichroic mirror that reflects red light and transmits blue light and green light. 54. A light source driving device 51 drives the light emitting diode 42.
[Illumination optics]
The illumination optical system 70 includes a condensing lens 71, a light tunnel 72 that converts green light, blue light, and red light introduced by the condensing lens 71 into uniform illumination light by internal multiple reflection, and the light tunnel 72. It has the condensing lens 73 which condenses the emitted illumination light, and the mirrors 74 and 75 which illuminate the image forming element 60 by reflecting the illumination light condensed by the condensing lens 73.
[Operation]
Next, the operation of the projection apparatus 10 configured as described above will be described.

  The control device 90 drives the motor M of the fluorescent device 30 to rotate the substrate 31. Further, the light source driving device 35 is operated to drive the laser light emitting diodes 22N1 to 22N9 of the illumination light source device 20, and blue laser light as excitation light is emitted from each of the laser light emitting diodes 22N1 to 22N9. The blue laser light is condensed by the coupling lenses 23R1 to 23R9 and the condenser lens 24, and condensed in a spot shape on the phosphor 32 of the substrate 31 of the fluorescent device 30 via the birefringent member 25 and the dichroic mirror 26. Is done.

  FIG. 7 shows spot lights P1 to P9 formed on the phosphor 32 when the birefringent member 25 is not provided. As shown in FIG. 7, the blue laser light emitted from each of the laser light emitting diodes 22N1 to 22N9 is not condensed at one point. This is because spot lights P1 to P9 corresponding to the number of laser light emitting diodes 22N1 to 22N9 are discretely formed due to variations in assembly of laser light emitting diodes 22N1 to 22N9 and coupling lenses 23R1 to 23R9.

  A set of discretely formed spot lights P1 to P9 is defined as a synthesized spot SP, and the size of the synthesized spot SP is a size indicating the maximum area of the area to which each spot light P1 to P9 is discretely irradiated. And

  For the sake of simplicity, if the size of the synthesized spot SP is defined as the smallest circle that is inscribed by each of the spot lights P1 to P9, a non-irradiated region or an irradiated power is irradiated inside this circle, that is, the synthesized spot SP. There is a region where the intensity of the is small. The emission efficiency of the fluorescence can be improved by reducing the area where the intensity of the irradiation power is low or the area where the irradiation power is not irradiated as much as possible.

  By the way, since the FFP of the laser light emitting diodes 22N1 to 22N9 is several μm, it may be regarded as a point light source. The arrangement positions of the laser light emitting diodes 22N1 to 22N9 and the coupling lenses 23R1 to 23R9 are designed so that this point light source is formed on the phosphor 32. Although depending on the design, the size of the point light source is generally about several millimeters to 1 mm on the phosphor 32, and about 3 mm at most.

  However, the nine spot lights P1 to P9 can hardly overlap at one point due to the arrangement accuracy of the nine laser light emitting diodes 22N1 to 22N9 and the variation in the relative positional relationship with the coupling lenses 23R1 to 23R9. When this is actually performed, many adjustments are necessary, and in view of the adjustment time, it is better to avoid the execution.

  Therefore, in this embodiment, it is assumed that no adjustment is performed. As a positional deviation between the laser light emitting diodes 22N1 to 22N9 and the coupling lenses 23R1 to 23R9, the spot light is increased by about 0.05 mm. Further, when the variation of the light emitting point position due to the manufacturing error of the laser light emitting diodes 22N1 to 22N9, the size variation of the coupling lenses 23R1 to 23R9, and other errors are accumulated, the spot light of about 0.1 mm to 0.5 mm is obtained. An error in the size of the diameter can occur.

  In this case, the variation in the diameter of one spot light is as small as about 1 mm or less, but the combined spot diameter is larger than the diameter of one spot light. Although it depends on the optical system, it is about several mm to 5 mm.

  Here, even if the shift amount d is increased by about 0.5 mm, the combined spot diameter is only increased by the shift amount d, so that the size of the fluorescent light emitting portion on the phosphor 32 is increased and the panel (screen) is increased. The decrease in lighting efficiency is hardly affected.

  In the birefringent member 25, as shown in FIG. 6B, the polarization directions of the laser light emitting diodes 22N1 to 22N9 are 45 degrees with respect to the Y direction of the birefringent member 25. ˜P9 are separated into two of an ordinary ray (first optical path) L2 and an extraordinary ray (second optical path) L3 by the birefringent member 25 as shown in FIG. Then, as shown in FIG. 8, spot light (first excitation light) P1a to P9a due to ordinary rays and spot light (second excitation light) P1b to P9b due to extraordinary rays are shifted by a distance d, thereby causing the phosphor 32 to move. Irradiate.

  Since the spot lights P1a to P9a and P1b to P9b that irradiate the phosphor 32 are excitation light of blue light, green light fluorescence is emitted from the irradiated portion of the phosphor 32.

  Incidentally, since the size of the synthesized spot SP shown in FIG. 7 is sufficiently larger than the value of the shift amount d, the size of the synthesized spot SP1 shown in FIG. 8 is almost the same as the size of the synthesized spot SP depending on the shift amount d. Absent.

  That is, without increasing the size of the light source as the secondary light source, the excitation light is irradiated to a region of low irradiation power intensity that was not originally used for light emission or a region that is not irradiated, so that the luminous efficiency of the phosphor 32 is increased. be able to.

  That is, even if the power of the blue laser light, which is the excitation light emitted from the laser light emitting diodes 22N1 to 22N9, is increased to a predetermined level or more, the power of the green fluorescent light emitted from the phosphor 32 does not reach the peak, and the excitation is performed. The power of the fluorescent light emitted from the phosphor can be increased in accordance with the power of the blue laser light that is light.

  Further, since the phosphor 32 provided on the substrate 31 is formed in a band shape along the circumferential direction of the substrate 31, the direction in which the spot lights P1b to P9b are shifted by the birefringent member 25 is shown in FIG. Set in the horizontal direction. By doing in this way, even if the synthetic spot SP1 spreads somewhat, it can be prevented from protruding from the phosphor 32, and a decrease in the luminous efficiency of the phosphor 32 is prevented.

  Further, since the diameter of the synthesized spot SP1 is longer in the shifting direction than in the non-shifting direction, if the shift direction is set to shift in the longitudinal direction of the panel in accordance with the aspect ratio of the panel (screen), the fluorescence The use efficiency of the fluorescence emitted from the body 32 can be improved.

  The green light emitted from the phosphor 32 is reflected by the dichroic mirror 26 as shown in FIG. 5, passes through the dichroic mirrors 44 and 54 shown in FIG. 4, and is introduced from one end of the light tunnel 72 by the condenser lens 71. . The introduced green light is emitted from the other end of the light tunnel 72, collected by the condenser lens 73, reflected by the mirrors 74 and 75, and illuminates the image forming element 60.

  The image forming element 60 is controlled by the control device 90 to form a green image having a green component. When green light is illuminated on the green image, the green light reflected by the green image is applied to the projection optical system 80. Incident. The projection optical system 80 enlarges and projects the incident green light onto a screen (not shown) to form a green component image.

  Thereafter, the control device 90 stops driving the laser light emitting diodes 22N1 to 22N9 of the illumination light source device 20 and operates the light source driving device 41 to drive the light emitting diodes 42. The light emitting diode 42 is driven to emit blue light, and this blue light is collected by the condenser lens 43 and reaches the dichroic mirror 44, where it is reflected and transmitted through the dichroic mirror 54. It is introduced from one end of the tunnel 72.

  On the other hand, the image forming element 60 forms a blue image having a blue component by the control device 90, and this blue image is illuminated in the same manner as described above by the blue light emitted from the other end of the light tunnel 72. The blue light reflected by the blue image is enlarged and projected onto the screen by the projection optical system 80 to form a blue component image.

Thereafter, the control device 90 stops the operation of the light source driving device 41 to stop the driving of the light emitting diode 42, stops the emission of blue light, and operates the light source driving device 51 to drive the light emitting diode 52. . The light emitting diode 52 is driven to emit red light. In the same manner as described above, the red light is condensed on the condenser lens 53 and reaches the dichroic mirror 54, where it is reflected and reflected by the condenser lens 71. It is introduced from one end.
On the other hand, the image forming element 60 forms a red image having a red component by the control device 90, and this red image is illuminated in the same manner as described above by the red light emitted from the other end of the light tunnel 72. The red light reflected from the red image is enlarged and projected onto the screen by the projection optical system 80 to form a red component image.
By repeating these operations in a short time, a full image is formed and displayed on the screen.
Since the projection apparatus 10 of the first embodiment uses only two light emitting diodes 42 and 52 without using three expensive solid-state light sources having large power, the cost can be suppressed. .
Further, since green light having high visibility characteristics is emitted from the phosphor 32, the power of the laser light emitting diodes 22N1 to 22N9 that emit blue laser light as excitation light may be considerably small. For this reason, the cheap illumination light source device 20 and the projection device 10 can be provided.
[Second Embodiment]
FIG. 9 shows the arrangement direction of the laser light emitting diodes 22N1 to 22N9 of the second embodiment. In the second embodiment, the laser light emitting diodes 22N1 to 22N9 are arranged in an annular shape to increase the cooling efficiency of the laser light emitting diodes 22N1 to 22N9. Other configurations are the same as those of the first embodiment.
The polarization directions of the laser light emitting diodes 22N1 to 22N9 are the same as those in the first embodiment, and the same effects as those in the first embodiment can be obtained.
[Third embodiment]
FIG. 10 shows the arrangement direction of the laser light emitting diodes 22N1 to 22N9 of the third embodiment. In the third embodiment, the laser light emitting diodes 22N1 to 22N9 are arranged in an annular shape and the polarization direction (arrow direction) of the laser light is arranged in an annular shape.
The spread angle of the laser light emitted from the laser light emitting diode 22N1 is large in the polarization direction (arrow direction), and small in the direction orthogonal to the polarization direction, and the spot shape of the laser light is elliptical D1 to D9. .
For this reason, when the polarization direction of the laser beam is arranged in an annular shape, the larger spread angle is along the circumferential direction, and the smaller spread angle is located on the outer peripheral side. Thereby, the coupling efficiency of the laser beam by the condensing lens 24 can be improved.
[Fourth embodiment]
11 and 12 show a fourth embodiment. In the fourth embodiment, birefringent members 25F1 to 25F9 are arranged between the laser light emitting diodes 22N1 to 22N9 and the coupling lenses 23R1 to 23R9 corresponding to the laser light emitting diodes 22N1 to 22N9.

  According to the fourth embodiment, by rotating the birefringent members 25F1 to 25F9 in the X and Y planes corresponding to the polarization directions of the laser light emitting diodes 22N1 to 22N9, the intensity ratio between the ordinary ray and the extraordinary ray is obtained. Can be adjusted individually.

  FIG. 13 shows a state in which the birefringent members 25F1 to 25F9 are rotated in the X and Y planes corresponding to the polarization directions of the laser light emitting diodes 22N1 to 22N9. That is, with respect to the polarization direction that acts as an ordinary ray (or extraordinary ray) of the birefringent members 25F1 to 25F9 (the polarization direction in which the X-axis direction acts as an ordinary ray, the polarization direction in which the Y-axis direction acts as an extraordinary ray), The polarization directions of 22N1 to 22N9 are relatively rotated by 45 degrees. By doing in this way, the intensity ratio of an ordinary ray and an extraordinary ray becomes equal.

  According to the fourth embodiment, since the birefringent members 25F1 to 25F9 are individually arranged for the laser light emitting diodes 22N1 to 22N9, the light sources of all the laser light emitting diodes 22N1 to 22N9 are separated by the shift amount d. It can be as if there are two light sources.

Further, by individually adjusting the polarization direction of the laser light emitting diodes 22N1 to 22N9 and the direction of the birefringent members 25F1 to 25F9, the shifting direction can be set to an arbitrary direction of 360 degrees. For example, the shift direction can be determined so as to be divided toward the center line of the laser light emitting diodes 22N1 to 22N9 arranged in an annular shape. This detailed description is described in FIG.
By shifting the spot lights P1b to P9b (see FIG. 8) caused by extraordinary rays toward the center, the irradiation power density of the excitation light can be reduced without changing the synthesized spot size.

  In the fourth embodiment, the laser light emitting diodes 22N1 to 22N9 are arranged in an annular shape. However, when the shift direction is set to the inner side, the same effect can be obtained even when arranged in a matrix.

In the fourth embodiment, the birefringent members 25F1 to 25F9 are arranged corresponding to the laser light emitting diodes 22N1 to 22N9, but it is not always necessary to correspond one-to-one. For example, when it is not necessary to set the intensity ratio of ordinary rays and extraordinary rays to 50:50, three laser light emitting diodes 22N1, 22N9, 22N2 including the laser light emitting diodes 22N9, 22N2 on both sides of the laser light emitting diode 22N1 are set to 1. If the shift direction is adjusted by one birefringent member, three birefringent members are sufficient for the nine laser light emitting diodes 22N1 to 22N9. For this reason, cost reduction and assembly adjustment work can be omitted.
[Fifth embodiment]
FIG. 14 shows a fifth embodiment. In the fifth embodiment, two laser beams emitted from the laser light emitting diodes 22N1 to 22N9 using the half mirrors H1 to H9 and the reflection mirrors E1 to E9 are used without using a birefringent member. It is designed to be branched. The half mirrors H1 to H9 and the reflection mirrors E1 to E9 are arranged substantially in parallel, and the half mirrors E1 to E9 and the reflection mirrors E1 to E9 with respect to the transmitted light (transmission excitation light) transmitted through the half mirrors H1 to H9. The reflected light beam (reflected excitation light) reflected by is shifted by being shifted.

By adjusting the angles of the reflection mirrors E1 to E9, the shift amount of the reflected light beam with respect to the transmitted light beam can be freely set.
In the fifth embodiment, the laser light emitting diodes 22N1 to 22N9 are arranged in a matrix as shown in FIG. 6, and the coupling lenses 23R1 to 23R9, the half mirrors H1 to H9, and the reflection mirrors E1 to E9 are also arranged in the matrix. However, they may be arranged in an annular shape as shown in FIGS.
[Sixth embodiment]
FIG. 15A shows the positions of the spot light Qa and Qb of the ordinary and extraordinary rays separated by the birefringent member 3 with respect to the birefringent member 3, and the polarization directions Ua and Ub of the spot lights Qa and Qb. It is a thing.

FIG. 15B shows the positions of the spot lights Qa and Qb with respect to the birefringent member 3 and the spots when the birefringent member 3 is rotated 45 degrees counterclockwise from the position of FIG. The polarization directions Ua and Ub of the light Qa and Qb are shown.
FIG. 15C shows the positions of the spot lights Qa and Qb with respect to the birefringent member 3 and the spots when the birefringent member 3 is rotated 90 degrees counterclockwise from the position of FIG. The polarization directions Ua and Ub of the light Qa and Qb are shown.

  As can be seen from FIGS. 15A to 15C, even when the birefringent member 3 is rotated, the position of the ordinary light spot light Qa does not change, but the extraordinary light spot light Qb is the same as the spot light Qa. The birefringent member 3 rotates around the position according to the rotation.

That is, it can be seen that when the light beam is split into two light beams, an ordinary light beam and an extraordinary light beam, the direction in which the light beam is divided can be set according to the rotation of the birefringent member 3. That is, the extraordinary light spot light can be shifted in a predetermined direction. For example, it is possible to shift the laser light emitting diodes 22N1 to 22N9 arranged in an annular shape shown in FIG.
If this principle is applied, two spot lights branched into two can be further branched by arranging the birefringent members in multiple stages.
FIG. 16 shows the sixth embodiment. In the sixth embodiment, the birefringent members 25 and 25A are arranged in two stages, and the birefringent member 25 and the birefringent member 25A are rotated so that the directions of the crystal axes are different from each other. Spot light can be obtained.
Note that the polarization directions of the ordinary ray and the extraordinary ray transmitted through the birefringent member 25 are polarized in directions orthogonal to each other. For this reason, when the birefringent member 25A is rotated by 45 degrees with respect to the birefringent member 25, the ratio of the spot light branched by the birefringent member 25A becomes 1: 1, and the branching effect is exhibited. . It is also possible to overlap the birefringent member in three steps and four steps.
In the above embodiment, the illumination light source device 20 emits green fluorescence, but may be provided in place of the blue light source device 40 or the red light source device 50 so as to emit blue fluorescence or red fluorescence. In this case, the illumination light source device 20 is replaced with a light emitting diode that emits green light.

  The present invention is not limited to the above-described embodiments, and design changes and additions are permitted without departing from the scope of the claimed invention.

DESCRIPTION OF SYMBOLS 10 Projection apparatus 20 Illumination light source device 22N1-22N9 Laser light emitting diode (excitation light source: semiconductor laser element)
25 Birefringent member (optical path branching means)
32 phosphor (wavelength conversion member)
H1-H9 half mirror E1-E9 reflection mirror

JP 2011-13316 A

Claims (9)

An excitation light source that emits excitation light of a predetermined wavelength;
A wavelength conversion member that receives excitation light emitted by the excitation light source and emits light having a wavelength different from the predetermined wavelength;
An optical path branching unit that is disposed between the excitation light source and the wavelength conversion member and branches the optical path of the excitation light into at least two first optical paths and a second optical path;
Of the excitation light emitted from the excitation light source, the position where the first excitation light passing through the first optical path branched by the optical path branching unit and the second excitation light passing through the second optical path are incident on the wavelength conversion member The illumination light source device is characterized in that they are different. The illumination light source device according to claim 1, wherein the optical path branching means is a birefringent member. The optical path branching unit divides the excitation light into two parts, transmits one of them and reflects the transmitted excitation light and reflects the other into reflected excitation light, and the reflected excitation light reflected by the half mirror. The illumination light source device according to claim 1, further comprising a reflection mirror that reflects the light and enters the wavelength conversion member.   The illumination light source device according to any one of claims 1 to 3, wherein the excitation light source is a semiconductor laser element.   The illumination light source device according to claim 4, wherein a plurality of the semiconductor laser elements are provided, and the semiconductor laser elements are arranged so that the polarization directions of the laser beams are the same. The light source is a semiconductor laser element;
A plurality of the semiconductor laser elements are provided, and the birefringent member is provided for each semiconductor laser element,
3. The position of each birefringent member is adjusted so that the direction of positional deviation of the second optical path with respect to the first optical path is different according to the polarization direction of the laser light of each semiconductor laser element. The illumination light source device described. The light source is a semiconductor laser element;
A plurality of the semiconductor laser elements are provided,
The illumination light source device according to claim 2, wherein the birefringent member is arranged for each of a plurality of semiconductor laser elements arranged adjacent to each other.   The illumination light source device according to claim 6, wherein the direction of positional deviation of the second optical path is an inner direction of a combined spot of laser beams formed on the wavelength conversion member.   An illumination light source device according to any one of claims 1 to 8, an image forming element illuminated with illumination light obtained by the illumination light source device, and an image formed by the image forming element on a screen A projection optical system for projecting toward the projector.