JP2016218459A - projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a projector that can suppress irregularity of intensity of light of each color.SOLUTION: A projector according to the present technology includes a pair of electrodes. The projector comprises: a solid state light source element that emits excitation light having a polarization surface along an array direction of the pair of electrodes; a support member that supports the solid state light source element so that the pair of electrodes is arrayed in a prescribed direction; a rotation substrate that transmits the excitation light; and a polarization conversion element that includes a plurality of transparent substrates arrayed in a direction different from the prescribed direction and non-orthogonal to the prescribed direction in an in-plane vertical to an incidence direction of transmission light transmitting the rotation substrate, and a ps-separation film provided between the plurality of transparent substrates and the polarization conversion element, and capable of separating a polarization component of the transmission light into a p-polarization component and s-polarization component.SELECTED DRAWING: Figure 2

Description

  The present technology relates to a light source device and a projector using the light source device.

  In recent years, a technique using a laser light source as a light source of a projector has been proposed. Patent Document 1 proposes to use laser light, which is coherent light emitted from a laser light source, by being scattered by a scattering element mixed with a fluorescent material. In this light source device, the speckle noise of the emitted light is reduced by reducing the coherency of the laser light, while the fluorescent light emitted from the scattering element excited by the laser light is combined with the emission colors of the laser light. Color reproduction can be performed (see, for example, paragraph [0018] of Patent Document 1).

  Since the light source device of Patent Document 1 uses fluorescence that is randomly polarized light (natural light, in which the polarization direction is random), light loss is likely to increase, and by aligning the polarization direction of the fluorescence using a polarization conversion element, The use efficiency of light is increased. The polarization conversion element includes a polarization separation element, a reflection mirror, and a polarization rotation element. The light incident on the polarization separation element is separated into a polarization component in the first polarization direction (p-polarization component) and a polarization component in the second polarization direction (s-polarization component) orthogonal thereto, thereby providing two optical paths. Branches to and exits. A polarization rotation element provided in one of the two optical paths rotates the polarization plane of light by 90 °. Two optical paths are directed in parallel to the exit surface of the polarization conversion element by a reflecting mirror or the like. As a result, one light beam incident on the polarization conversion element can be converted into two light beams aligned with one polarization component and emitted.

JP 2012-3042 A

  When fluorescent light, which is randomly polarized light that does not have a specific polarization plane, enters the polarization conversion element, it diverges relatively evenly into two optical paths corresponding to the polarization components and exits. However, when laser light that is polarized light is incident on the polarization conversion element, it may be emitted while being biased to one of the optical paths depending on the direction of the polarization plane. Therefore, on the light source surface of the light source device (the exit surface of the polarization conversion element), the color light beam due to fluorescence is evenly distributed, while the color light beam due to laser light is not uniformly distributed, and the light intensity distribution is colored. Will cause non-uniformity.

  In view of the circumstances as described above, an object of the present technology is to provide a light source device and a projector that can suppress non-uniformity of light intensity of each color.

In order to achieve the above object, a projector according to the present technology provides:
A solid-state light source element that has a pair of electrodes and emits excitation light having a polarization plane along the arrangement direction of the pair of electrodes;
A support member that supports the solid-state light source element so that the pair of electrodes are arranged in a predetermined direction;
A rotating substrate that transmits the excitation light;
A plurality of transparent substrates arranged in a direction different from the predetermined direction and in a non-orthogonal direction with respect to the predetermined direction within a plane perpendicular to the incident direction of transmitted light transmitted through the rotating substrate; A polarization conversion element provided between a plurality of transparent substrates and having a ps separation film capable of separating the polarization component of the transmitted light into a p-polarization component and an s-polarization component.

  The rotating substrate is a phosphor wheel.

The plurality of transparent substrates are composed of a plurality of first substrates and a plurality of second substrates, and the first substrates and the second substrates are alternately arranged,
The first substrate is
An incident side end face on which the transmitted light is incident;
A first surface provided with the ps separation film and inclined at a predetermined angle with respect to the incident side end surface;
An exit-side end face provided parallel to the entrance-side end face;
A second surface provided in parallel to the first surface,
The second substrate is
An incident side end face on which the transmitted light is incident;
A third surface provided to be inclined at the predetermined angle with respect to the incident side end surface;
An exit-side end face provided parallel to the entrance-side end face;
A fourth surface provided in parallel to the third surface,
The first surface of the first substrate and the fourth surface of the second substrate are connected via the ps separation film,
The second surface of the first substrate and the third surface of the second substrate are connected via a total reflection film.

The solid-state light source element generates excitation light from a violet wavelength region to a blue wavelength region,
The phosphor included in the phosphor wheel emits the linearly polarized light in a state where the polarization plane of the excitation light from the violet wavelength region to the blue wavelength region is maintained as the transmitted light.

The light source device includes a polarization conversion element, a phosphor, and a light source element.
The polarization conversion element includes a ps separation film capable of separating a polarization component of incident light into a p-polarization component and an s-polarization component.
The phosphor can emit visible light having a wavelength longer than the wavelength of the excitation light, which is generated by being excited by excitation light, as the incident light incident on the ps separation film.
The light source element emits laser light in a predetermined wavelength region as the excitation light, and irradiates the phosphor with the excitation light, thereby forming a polarization plane between the polarization plane of the p-polarization and the polarization plane of the s-polarization. The laser light emitted from the phosphor can be irradiated as the incident light.

  In the polarization conversion element, when the incident light is incident on the ps separation film in a state where both the p and s polarization components are present, the optical path of the p polarization component and the s are similar to the visible light of other colors that are randomly polarized. The light is branched and emitted to the optical path of the polarization component. Therefore, a light source device that can suppress non-uniformity of the light intensity of each color is obtained.

  The light source device may further include a support member that supports the light source element so that the polarization plane of the incident light is positioned between the polarization plane of the p-polarized light and the polarization plane of the s-polarized light.

  The support member supports the light source element in a state where the polarization plane of the laser light emitted from the light source element is directed in an appropriate direction. Accordingly, the ps separation film can be irradiated with laser light emitted from the phosphor in a state where both p and s polarization components are included.

  When the angle of the reference polarization plane, which is the polarization plane in which the p-polarization component and the s-polarization component are 1: 1, is 0 °, the angle θ of the polarization plane of the incident light is −−. The light source element may be supported so that 20 ° ≦ θ ≦ 20 °. Preferably, the support member supports the light source element so that an angle of a polarization plane of the incident light coincides with the reference plane polarization plane.

  By using the support member described above, the polarization plane of the laser light emitted from the phosphor is positioned in an angular region where the polarization components of p and s are nearly equal, thereby making the light intensity distribution uniform. it can.

Another light source device according to the present technology includes a polarization conversion element, a phosphor, a plurality of light source elements, and a support member.
The polarization conversion element includes a ps separation film capable of separating a polarization component of incident light into a p-polarization component and an s-polarization component.
The phosphor can emit visible light having a wavelength longer than the wavelength of the excitation light, which is generated by being excited by excitation light, as the incident light incident on the ps separation film.
The plurality of light source elements respectively emit laser light in a predetermined wavelength range as the excitation light, and irradiate the phosphor with the excitation light, whereby the plurality of laser lights emitted from the phosphor are separated by the ps. Irradiation is possible as a plurality of incident light incident on the film.
The support member has a combined vector direction obtained by combining vector directions along the polarization planes of the plurality of incident lights when viewed in the optical axis direction, and a polarization plane of the p-polarized light and the s as viewed in the optical axis direction. The plurality of light source elements are supported so as to face the polarization plane of polarized light.

  When the incident light is laser light from a plurality of light source elements, the directions of the polarization planes obtained by combining the directions of the plurality of polarization planes (combined vector directions) are p-polarization plane and s-polarization plane. In between, it is possible to irradiate the ps separation film with both polarization components of p and s as a whole.

  The support member is arranged so that the direction of the combined vector is within ± 20 ° with respect to a polarization plane in which the p-polarized component and the s-polarized component are 1: 1 when viewed in the optical axis direction. A plurality of light source elements may be arranged.

  The direction of the polarization plane obtained by synthesizing the directions of the plurality of polarization planes of the laser light from the plurality of light source elements is directed to an angular region where the polarization components of p and s are approximately equal, so that p and s as a whole are obtained. The polarization component can be emitted uniformly, and the light intensity distribution can be made uniform.

  The plurality of light source elements include a first light source element capable of irradiating laser light having a first polarization plane as first incident light out of the plurality of incident lights, and laser light having a second polarization plane. You may have the 2nd light source element which can be irradiated as 2nd incident light among these incident light. The support member may be arranged with the first light source element and the second light source element so that the first polarization plane and the second polarization plane are perpendicular to each other.

When the directions of the polarization planes of the laser beams from the two light source elements are perpendicular to each other, the ratio of the polarization components of p and s is reversed between the polarization plane of one laser beam and the polarization plane of the other laser beam. By adding these together, the light intensity distribution can be made uniform easily.
A projector according to an embodiment of the present technology includes the above-described light source device and an image generation element that generates an image using light emitted from the light source device.

  By applying the light source device described above to a projector, it is possible to suppress non-uniformity of each display color within the image display surface and contribute to an improvement in image quality.

  As described above, according to the present technology, it is possible to suppress non-uniformity of the light intensity of each color in the light source device.

FIG. 1 is a schematic diagram illustrating a configuration of a light source device according to the first embodiment of the present technology. FIG. 2 is a diagram schematically showing the polarization state of the light in FIG. FIG. 3 is a diagram showing the laser light source in FIG. FIG. 4 is a diagram for explaining the polarization plane of incident laser light. FIG. 5 is a diagram illustrating the light intensity distribution on the exit surface of the polarization conversion element by the light source device. FIG. 6 is a diagram illustrating a light source device according to a first comparative example. FIG. 7 is a diagram showing the light intensity distribution on the exit surface of the polarization conversion element shown in FIG. FIG. 8 is a diagram illustrating a light source device according to a second comparative example. FIG. 9 is a diagram showing the light intensity distribution on the exit surface of the polarization conversion element shown in FIG. FIG. 10 is a diagram illustrating a light source device according to a third comparative example. FIG. 11 is a diagram showing the light intensity distribution on the exit surface of the polarization conversion element shown in FIG. FIG. 12 is a diagram schematically illustrating a light source device according to the second embodiment of the present technology and the polarization state of light thereby. FIG. 13 is a schematic diagram illustrating a configuration of a projector using the light source device.

  Hereinafter, embodiments according to the present technology will be described with reference to the drawings.

<First Embodiment>
FIG. 1 is a schematic diagram illustrating a configuration of a light source device according to the first embodiment of the present technology. The light source device 1 is for a projector of a type that emits white light by combining light in a blue wavelength region and light in a red wavelength region generated from a fluorescent material excited by the laser light and in a green wavelength region. It is a light source device.

The light source device 1 includes a laser light source 2, a condenser lens 22, a phosphor wheel 3, a collimating optical system 4, an integrator element 40, a polarization conversion element 5, and the like.
The laser light source 2 that is a light source element emits laser light in a predetermined wavelength range toward the phosphor wheel 3. The laser light source 2 is a blue laser light source capable of oscillating blue laser light B1 having a peak wavelength of emission intensity within a wavelength range of 400 nm to 500 nm, for example.

  The condenser lens 22 includes one or a plurality of convex lenses, and is disposed between the laser light source 2 and the phosphor wheel 3 on the optical axis of the laser light emitted from the laser light source 2. The condensing lens 22 condenses the blue laser light B <b> 1 emitted from the laser light source 2.

  The phosphor wheel 3 includes a disk-shaped substrate 31 that transmits the blue laser light B <b> 1 and a phosphor layer 32 provided on the substrate 31. The phosphor wheel 3 is arranged so that the main surface of the two main surfaces of the substrate 31 on the side where the phosphor layer 32 is not provided faces the condenser lens 22 side. A motor 35 for driving the phosphor wheel 3 is connected to the center of the substrate 31, and the phosphor wheel 3 has a rotation axis 33 at a normal line passing through the center of the substrate 31, and is rotatable about the rotation axis 33. Is provided. Further, the phosphor wheel 3 is arranged so that the focal position of the blue laser light B <b> 1 condensed by the condenser lens 22 coincides with the position of the phosphor layer 32.

  The phosphor layer 32 contains a fluorescent substance that uses the blue laser light B1 as excitation light and is excited by the excitation light to generate visible light having a wavelength longer than the wavelength of the excitation light. For example, the phosphor layer 32 includes a substance that emits fluorescence when excited by blue laser light having a center wavelength of about 445 nm, and a part of the blue laser light B1 emitted from the laser light source 2 is emitted from the red wavelength region. The light is converted into light in a wavelength region including the green wavelength region (that is, yellow light) and emitted. As such a fluorescent material, for example, a YAG (yttrium, aluminum, garnet) phosphor is used.

  Further, the phosphor layer 32 absorbs a part of the excitation light, and also allows the blue laser light B1 emitted from the laser light source 2 to be emitted by transmitting a part of the excitation light. Thereby, the light emitted from the phosphor layer 32 becomes white light due to the color mixture of the blue excitation light and the yellow fluorescence. Thus, in order to transmit a part of excitation light, the fluorescent substance layer 32 may contain the filler particle | grains which are the particulate substances which have a light transmittance, for example.

  When the substrate 31 is rotated by the motor 35, the laser light source 2 irradiates the phosphor layer 32 with excitation light while relatively moving the irradiation position on the phosphor layer 32. Therefore, in the phosphor wheel 3, the blue laser beam B1 from the laser light source 2 and the fluorescence converted from the blue laser beam 2 can be obtained while avoiding deterioration caused by irradiating the same position with the excitation light for a long time.

  The collimating optical system 4 includes one or a plurality of convex lenses, collimates the light from the phosphor wheel 3 and irradiates the integrator element 40.

  The integrator element 40 includes a first fly-eye lens 41 having a plurality of microlenses arranged two-dimensionally, and a second having a plurality of microlenses arranged to correspond to each of the microlenses. The fly eye lens 42 is included. The parallel light incident on the integrator element 40 from the collimating optical system 4 is divided into a plurality of light beams by the microlens of the first fly-eye lens 41 and imaged on the corresponding microlens in the second fly-eye lens 42, respectively. The Each of the microlenses of the second fly-eye lens 42 functions as a secondary light source and irradiates the polarization conversion element 5 with incident light as a plurality of parallel lights with uniform brightness.

  As a whole, the collimating optical system 4 and the integrator element 40 have a function of adjusting incident light irradiated from the laser light source 2 and the phosphor wheel 3 to the polarization conversion element 5 into a uniform luminance distribution.

  The polarization conversion element 5 has a function of aligning the polarization state of incident light irradiated from the laser light source 2 and the phosphor wheel 3 and incident through the integrator element 40 and the like. The polarization conversion element 5 emits outgoing light including blue laser light B2, green light G2, and red light R2 through, for example, a superimposing lens 150 disposed on the outgoing side of the light source device 1.

  FIG. 2 is a diagram schematically showing the polarization state of the light in FIG. The condensing lens 22, the collimating optical system 4, the integrator element 40, and the like can be configured so as not to have a substantially large influence on the polarization state of light, and illustration and description thereof are omitted below.

  The polarization conversion element 5 typically has a rectangular outer shape when viewed in the optical axis direction. Referring to FIG. 2, the polarization conversion element 5 includes a plurality of strip-shaped substrates 10a and 10b that are long in the direction perpendicular to the paper surface of FIG. These substrates 10 a and 10 b are arranged alternately and are bonded by an adhesive layer 14. A ps separation film 11 is provided between the substrate 10a and the substrate 10b on the left side in the figure. A total reflection film 12 is provided between the substrate 10a and the right substrate 10b in the drawing.

  The substrate 10a and the substrate 10b are transparent substrates made of glass or the like. As shown in FIG. 2, for example, the substrate 10a and the substrate 10b have a parallelogram shape with one diagonal of about 45 ° and the other diagonal of about 135 °. ing. For example, a plurality of glass substrates are prepared. The ps separation film 11 is deposited on the main surface of a part (substrate 10a) of them, and the total reflection film 12 is deposited on the main surface of the remaining substrate (substrate 10b). After bonding these substrates 10a, 10b, 10a, 10b,..., The substrate is cut out at an angle of 45 ° with the main surface, whereby the polarization conversion element 5 is manufactured. The cut-out surfaces are an incident side end surface and an emission side end surface. The thickness of each of these substrates is, for example, 2 to 4 mm.

  A retardation film 13 is provided on each substrate 10b on the light emission side end face of the polarization conversion element 5. In addition, a light shielding film 15 is provided on each substrate 10 b on the light incident side end face of the polarization conversion element 5. The light shielding film 15 is provided on the light incident side of the substrate 10b, and the light shielding film 15 is not provided on the light incident side of the substrate 10a.

  In the polarization conversion element 5, the light shielding film 15 is arranged on the incident side end face of the substrate 10b, so that the incident light from the phosphor 32 enters from the end face of the substrate 10a. Since the ps separation film 11 is disposed obliquely to the incident side end face of the substrate 10a, the incident light is incident on the ps separation film 11 in an oblique direction.

  The ps separation film 11 is a so-called PBS (Polarizing Beam Splitter) and is formed of a dielectric multilayer film. The ps separation film 11 has a function of separating the polarization component of incident light into a p-polarization component and an s-polarization component. The ps separation film 11 transmits a p-polarized component having a polarization plane parallel to the incident plane (a plane including the optical axes of incident light and reflected light), and reflects an s-polarized component having a polarization plane perpendicular to the incident plane. .

  The total reflection film 12 is a mirror formed of a metal film such as aluminum or a dielectric multilayer film. The total reflection film 12 reflects the light (s-polarized light) reflected by the ps separation film 11 and incident on the total reflection film 12, thereby passing the s-polarized light path through the ps separation film 11 (p-polarization). Parallel to the optical path.

  The retardation film 13 has a function of a half-wave plate and has a function of rotating the polarization direction of incident light by 90 °. Therefore, the retardation film 13 converts the p-polarized light that has been transmitted through the ps separation film 11 and entered the retardation film 13 into s-polarized light, and then emitted.

  As a whole, the polarization conversion element 5 converts the p-polarized component contained in the light emitted from the phosphor 32 into s-polarized light and emits it from the substrate 10b, and the s-polarized light contained in the light emitted from the phosphor 32. The component is emitted from the substrate 10a adjacent to the substrate 10b while maintaining the s-polarized light.

Here, the polarization component contained in the light emitted from the phosphor 32 will be described.
As shown in FIG. 2, the light emitted from the phosphor 32 is a part of the red light R1 and green light G1 as fluorescence and the blue laser light B1 that is excitation light from the laser light source 2.

  The red light R1 and the green light G1, which are fluorescent light, are random polarized light that does not have a specific polarization plane, and include both a p-polarized component and an s-polarized component. Can be separated. In the case of random polarization, since the ratio of the polarization components is relatively uniform, the amount of light is halved in the s-polarized light path (optical path Ls on the substrate 10a side) and the p-polarized light path (optical path Lp on the substrate 10b side). The light is branched and emitted (emitted light R2 and G2 in FIG. 2).

  On the other hand, the blue laser light B1 emitted from the phosphor 32 is linearly polarized light in a state where the polarization plane of the blue laser light B1 irradiated as excitation light is maintained. For this reason, the ratio of the polarization component of the blue laser light B 1 incident on the ps separation film 11 is determined by the direction of the polarization plane of the blue laser light B 1 emitted from the laser light source 2.

  As shown in FIG. 2, the light source device 1 is provided with a support substrate 20 as a support member that supports the laser light source 2. The support substrate 20 may be a circuit board, for example. The support substrate 20 supports the laser light source 2 so that the polarization plane of the blue laser light B1 is positioned between the p-polarization plane and the s-polarization plane. Specifically, the direction of the polarization plane of the blue laser light B1 is based on the orientation in which the laser light source 2 is arranged, in particular, the direction of the p polarization plane and the direction of the s polarization plane determined by the ps separation film 11. , Determined by the rotational angle position around the optical axis.

  FIG. 3 is a diagram showing the laser light source 2. 3 is a side view of the laser light source 2 and the support substrate 20 as viewed in the same direction as in FIG. 2, and the lower diagram is a front view of them as viewed in the optical axis direction. The laser light source 2 has a pair of electrodes 21, for example. For example, when the arrangement direction of these electrodes 21 (the direction of the arrow indicated by the alternate long and short dash line) coincides with the linear polarization plane of the laser light emitted from the laser light source 2, the arrangement direction of these electrodes 21 is the p-polarization plane and s The laser light source 2 may be attached to the support substrate 20 so as to be in the direction between the polarization planes.

  For example, the laser light source 2 is oriented so that the polarization plane of the p-polarization component and the s-polarization component is 1: 1, and the polarization plane of the blue laser light B1 is a polarization plane close to the reference polarization plane. Be placed. FIG. 4 is a diagram for explaining the polarization plane of incident laser light. As shown in FIG. 4, when the angle of the reference polarization plane is 0 °, the angles of the s polarization plane and the p polarization plane can be expressed as 45 ° and −45 °.

  Specifically, the support substrate 20 supports the laser light source 2 so that the angle θ of the polarization plane of the blue laser light B1 is −20 ° ≦ θ ≦ 20 °. In such a plane of polarization of the angle θ, the p-polarized component and the s-polarized component are in the range of about 30 to 70%, respectively, so that quantitative deviation between these polarized components is suppressed.

  The most preferable angle θ of the polarization plane is 45 °, which is the median value of the angles that coincide with the reference polarization plane, that is, the right angle between the p-polarized light and the s-polarized light.

  For example, as described above, the blue laser light B1 emitted from the laser light source 2 having a polarization plane that coincides with the reference polarization plane is separated into p-polarized light and s-polarized light by the ps separation film 11. The p-polarized component of the blue laser light B1 passes through the ps separation film 11 as p-polarized light, is converted into s-polarized light by the retardation film 13, and is emitted. The amount of light reflected by the ps separation film 11 and the amount of transmitted light are substantially the same. The s-polarized component of the blue laser light B1 is reflected by the ps separation film 11 and the total reflection film 12, and is emitted as s-polarized light from the region where the emission-side retardation film 13 is not provided.

  As described above, the blue laser light B1 that is polarized light can be branched and emitted into the optical path Lp of the p-polarized component and the optical path Ls of the s-polarized component, similarly to the visible light of other colors that are randomly polarized. . When the polarization plane of the incident light (B1) as the most preferable angle θ coincides with the reference polarization plane, the non-uniformity of the light quantity of the blue laser beam B2 branched into the left and right optical paths is suppressed.

  FIG. 5 is a diagram illustrating an intensity distribution of outgoing light on the outgoing side end face of the polarization conversion element 5 by the light source device 1. As a result of the above, the blue laser light B2 is distributed with substantially the same uniformity in the red light R2 and the green light G2.

<Comparative Example 1>
FIG. 6 schematically shows a light source device according to a first comparative example as a comparison with the light source device 1 according to the first embodiment. The same members as those in the above embodiment are given the same reference numerals.

  Similar to the light source device 1, the light source device 100 according to the first comparative example uses laser light as blue light and uses fluorescence as color light (red light and green light) in a longer wavelength region than blue. It is a light source device. The light source device 100 includes the same polarization conversion element 5 as the light source device 1 shown in FIG. However, unlike the light source device 1, the laser light source 91 is arranged so as to irradiate the polarization conversion element 5 with s-polarized light as incident light. The blue laser light Bs that is s-polarized light is all reflected by the ps separation film 11, enters the total reflection film 12, and is emitted through the optical path Ls on the s-polarization side (right side). In this case, blue laser light is not emitted in the optical path on the p-polarization side (left side).

  FIG. 7 shows the intensity distribution of the outgoing light on the outgoing side end face of the polarization conversion element 5 of the light source device 100. In this light source device 100, since the emitted blue laser light is biased to one optical path, the intensity distribution of the blue light on the emission surface becomes extremely uneven, and uniformity such as red light and green light can be obtained. Can not. Therefore, there arises a problem that the emitted white light becomes uneven.

<Comparative example 2>
FIG. 8 schematically shows a light source device according to a second comparative example. FIG. 9 shows the intensity distribution of the outgoing light on the outgoing side end face of the polarization conversion element 5 in the light source device 200. In the second comparative example, the laser light source 92 is arranged so as to irradiate the polarization conversion element 5 with p-polarized light as incident light. In this case, all the blue laser light Bp, which is p-polarized light, passes through the ps separation film 11, enters the retardation film 13, and is converted to s-polarized light. Accordingly, all the blue laser light is emitted on the left optical path Lp and is not emitted on the s-polarization side (right side). As a result, as shown in FIG. 9, the intensity distribution of blue light is significantly uneven as compared to red light and green light, and white light is uneven.

<Comparative Example 3>
FIG. 10 schematically shows a light source device according to a second comparative example. FIG. 11 shows the intensity distribution of outgoing light on the outgoing side end face of the polarization conversion element 95 in the light source device 310. In this example, as compared with the polarization conversion element 5, the positions of the total reflection film 12 provided on the polarization conversion element 95 and the adhesive layer 14 adjacent thereto are opposite to each other. That is, the total reflection film 12 is formed on the substrate 10c, and the adhesive layer 14 is provided between the total reflection film 12 and the substrate 10d on the right side in the drawing.

  A laser light source 93 is arranged so as to irradiate the polarization conversion element 95 with s-polarized light as incident light. In the light source device 310 according to the third comparative example, as in the first comparative example (see FIG. 6), the entire amount of blue laser light Bs as incident light is reflected by the ps separation film 11 and enters the total reflection film 12. To do.

  Here, as shown in FIG. 6, in the light source device 100, the blue laser light Bs enters the total reflection film 12 through the adhesive layer 14, is reflected by the reflection film 12, and passes through the adhesive layer 14 again. When the amount of blue laser light Bs passing through the adhesive layer 14 increases, the adhesive layer 14 may be deteriorated. In the light source device 310 shown in FIG. 10, the blue laser light Bs is totally reflected by the reflective film 12 without passing through the adhesive layer 14, so that photodegradation of the adhesive layer 14 can be avoided. However, as shown in FIG. 11, the problem remains that the intensity distribution of the blue light on the exit surface of the polarization conversion element 95 is uneven.

  According to the light source device 1 according to the first embodiment, the light amount of the s-polarized component incident on the adhesive layer 14 on the total reflection film 12 is reduced to half of the blue laser light B1 incident on the ps separation film 11. be able to. Thereby, deterioration of the adhesive layer 14 due to light can also be suppressed.

  From the viewpoint of preventing deterioration of the adhesive layer 14 due to such light, in the light source device 1, the polarization conversion element 95 of the light source device 310 may be used instead of the polarization conversion element 5.

  However, in order to manufacture the polarization conversion element 95, it is necessary to form the total reflection film 12 on the surface of the substrate 10c on which the ps separation film 11 is formed, on the side opposite to the ps separation film 11. That is, since it is necessary to form a film on both sides of the substrate, there remains a problem that the number of manufacturing steps increases.

  The light source device 1 can suppress deterioration by reducing the amount of laser light passing through each adhesive layer 14 while using the polarization conversion element 5 that can be manufactured by a relatively simple process. Therefore, a decrease in the reliability of the polarization conversion element can be avoided without increasing the manufacturing cost.

<Second Embodiment>
FIG. 12 is a diagram illustrating a laser light source in the light source device according to the second embodiment of the present technology. In this embodiment, the same members, functions, etc. included in the light source device 1 according to the first embodiment will be described with the simplification or omitted, and the differences will be mainly described.

  This light source device has a plurality of light source elements including laser light sources 201 and 202. The plurality of light source elements may be, for example, a laser array including a large number of laser light sources 201 and 202 including the same number of laser light sources 201 and 202.

  The laser light source 201 (first light source element) is in a predetermined posture so as to irradiate the phosphor layer 32 and the ps separation film 11 with the blue laser light B11 (first incident light) having the first polarization plane. It is attached to the support substrate 20. The laser light source 202 (second light source element) can emit blue laser light B12 (second incident light) having a polarization plane (second polarization plane) in a direction different from the first polarization plane. In such a posture, the laser light source 201 is attached to the support substrate 20 in a pair.

  Specifically, as shown in FIG. 14, the laser light source 201 and the laser light source 202, which are substantially the same elements, are supported on the support substrate 20 so that the rotational angle positions around the optical axis are shifted from each other. Is done. For example, by setting the difference in rotation angle position to 90 °, the first polarization plane and the second polarization plane of the plurality of laser beams incident on the ps separation film 11 can be made perpendicular to each other.

  In FIG. 12, the laser light source 201 is arranged to emit blue laser light B11 having a p-polarized polarization plane, and the laser light source 202 is arranged to emit blue laser light B12 having an s-polarized polarization plane. Has been. The laser light sources 201 and 202 can irradiate the ps separation film 11 with both p and s polarization components. Therefore, it is possible to emit the blue laser light B2 to both the optical path Lp (see FIG. 1) of the p-polarized component and the optical path Ls of the s-polarized component, thereby suppressing the deviation of the emitted light.

<Projector>
FIG. 13 is a schematic diagram illustrating a configuration of the projector 100 in which the light source device illustrated in FIG. 1 or 12 can be mounted. The projector 100 includes an optical engine 50 that uses light emitted from the light source device.

  The optical engine 50 includes dichroic mirrors 210 and 220, mirrors 230, 240 and 250, relay lenses 260 and 270, field lenses 300R, 300G and 300B, liquid crystal light valves 400R, 400G and 400B as image generating elements, dichroic prism 500 and A projection optical system 600 is included.

  The dichroic mirrors 210 and 220 have a property of selectively reflecting color light in a predetermined wavelength range and transmitting light in other wavelength ranges. Referring to FIG. 12, for example, the dichroic mirror 210 selectively reflects the red light R2. The dichroic mirror 220 selectively reflects the green light G2 out of the green light G2 and the blue light B2 transmitted through the dichroic mirror 210. The remaining blue light B2 passes through the dichroic mirror 220. Thereby, the light emitted from the light source device 1 is separated into a plurality of color lights of different colors.

  The separated red light R2 is reflected by the mirror 230, collimated by passing through the field lens 300R, and then enters the liquid crystal light valve 400R for modulating red light. The green light G2 is collimated by passing through the field lens 300G, and then enters the liquid crystal light valve 400G for green light modulation. The blue light B <b> 2 passes through the relay lens 260 and is reflected by the mirror 240, and further passes through the relay lens 270 and is reflected by the mirror 250. The blue light B2 reflected by the mirror 250 is collimated by passing through the field lens 300B, and then enters the liquid crystal light valve 400B for modulating blue light.

  The liquid crystal light valves 400R, 400G, and 400B are electrically connected to a signal source (not shown) (such as a PC) that supplies an image signal containing image information. The liquid crystal light valves 400R, 400G, and 400B modulate incident light for each pixel based on the supplied image signals of each color, and generate a red image, a green image, and a blue image, respectively. The modulated light of each color (formed image) enters the dichroic prism 500 and is synthesized. The dichroic prism 500 superimposes and synthesizes light of each color incident from three directions and emits the light toward the projection optical system 600. The projection optical system 600 irradiates a screen (not shown) with the light synthesized by the dichroic prism 500. Thereby, a full-color image is displayed.

  Since the light source device 1 equalizes the intensity distribution on the emission surface of each color light supplied to the optical engine 50, the projector 100 combines the blue image by the laser light with the red and green images by the fluorescence. In this case, it is possible to suppress variations in hue. Therefore, it is possible to suppress non-uniformity of each display color in the image display surface and contribute to improvement in image quality.

  <Other embodiments>

  When a plurality of laser light sources are provided as in the second embodiment, the directions of two different polarization planes of the blue laser beams B11 and B12 are not limited to the above example. For example, one or both of the polarization planes may be positioned between the p-polarization plane and the s-polarization plane.

  When a plurality of laser light sources are provided, the directions of the polarization planes of the plurality of blue laser beams are not limited to two types. For example, the plurality of laser light sources may be arranged so that the plurality of blue laser beams include three or more blue laser beams having different polarization plane directions. As a result, a plurality of blue laser beams having different polarization planes are incident on the ps separation film 11, so that the p-polarized component and the s-polarized component are surely included in the incident light. Therefore, the same effect as described above can be obtained.

  In this case, when viewed in the optical axis direction of the plurality of laser light sources, a combined vector direction obtained by combining the respective vector directions along the plurality of polarization planes by the laser light sources is a polarization plane of p-polarization and a polarization plane of s-polarization. The plurality of laser light sources may be supported by a support substrate so as to face each other. In particular, it is preferable that the angle θ1 in the combined vector direction is in a range of −20 ° ≦ θ1 ≦ 20 °, where the above-described reference polarization plane is 0 °. The most preferable form is a form in which the angle θ1 coincides with the reference polarization plane 0 °.

  The preferred form of the angle θ (and θ1) was −20 ° ≦ θ ≦ 20 °, but −15 ° ≦ θ ≦ 15 °, −10 ° ≦ θ ≦ 10 °, −5 ° ≦ θ ≦ 5. It may be °.

  In the above embodiment, blue laser light is used as excitation light for exciting the phosphor layer. However, the present invention is not limited to this, and blue-violet to violet laser light may be used as excitation light. In this case, the phosphor material can be appropriately selected according to the wavelength range of blue-violet to violet laser light (for example, the center wavelength of 405 nm, 420 nm, etc.).

  In the above-described embodiment, an example in which the laser light source is installed on the support substrate 20 so that the angle of the polarization plane is set is shown. However, instead of the installation angle of the laser light source, the angle of the polarization plane of the laser light source may be set by an element that aligns the polarization plane at a predetermined angle. For example, the element may include an element that converts light emitted from a laser light source into random polarized light and an element that extracts light of a polarization plane in a predetermined direction from the random polarized light.

  It is also possible to combine at least two feature portions among the feature portions of each embodiment described above.

The present technology can be configured as follows.
(1) a polarization conversion element having a ps separation film capable of separating a polarization component of incident light into a p-polarization component and an s-polarization component;
A phosphor capable of irradiating visible light having a wavelength longer than the wavelength of the excitation light, which is generated by being excited by excitation light, as the incident light incident on the ps separation film;
The phosphor having a polarization plane between the polarization plane of p-polarization and the polarization plane of s-polarization by emitting laser light of a predetermined wavelength region as the excitation light and irradiating the phosphor with the excitation light. A light source device comprising: a light source element capable of emitting laser light emitted from the light as the incident light.
(2) The light source device according to (1),
A light source device further comprising a support member that supports the light source element so that the polarization plane of the incident light is positioned between the polarization plane of the p-polarization and the polarization plane of the s-polarization.
(3) The light source device according to (2),
When the angle of the reference polarization plane, which is the polarization plane in which the p-polarization component and the s-polarization component are 1: 1, is 0 °, the angle θ of the polarization plane of the incident light is −−. A light source device that supports the light source element so that 20 ° ≦ θ ≦ 20 °.
(4) The light source device according to (3),
The support member supports the light source element such that an angle of a polarization plane of the incident light coincides with the reference polarization plane.
(5) a polarization conversion element having a ps separation film capable of separating a polarization component of incident light into a p-polarization component and an s-polarization component;
A phosphor capable of irradiating visible light having a wavelength longer than the wavelength of the excitation light, which is generated by being excited by excitation light, as the incident light incident on the ps separation film;
A plurality of laser beams emitted from the phosphors are incident on the ps separation film by emitting laser light in a predetermined wavelength region as the excitation light and irradiating the phosphors with the excitation light. A plurality of light source elements that can be irradiated as light;
A combined vector direction obtained by combining vector directions along the polarization planes of the plurality of incident lights when viewed in the optical axis direction is a polarization plane of the p-polarized light and a polarization plane of the s-polarized light when viewed in the optical axis direction. And a support member that supports the plurality of light source elements so as to face each other.
(6) The light source device according to (5),
The support member is arranged so that the direction of the combined vector is within ± 20 ° with respect to a polarization plane in which the p-polarized component and the s-polarized component are 1: 1 when viewed in the optical axis direction. A light source device in which a plurality of light source elements are arranged.
(7) The light source device according to (6),
The plurality of light source elements include a first light source element capable of irradiating laser light having a first polarization plane as first incident light out of the plurality of incident lights, and laser light having a second polarization plane. A second light source element capable of being irradiated as second incident light among the plurality of incident light,
The light source device, wherein the support member includes the first light source element and the second light source element such that the first polarization plane and the second polarization plane are perpendicular to each other.
(8) a polarization conversion element having a ps separation film capable of separating a polarization component of incident light into a p-polarization component and an s-polarization component;
A phosphor that is excited by excitation light and is capable of irradiating visible light having a wavelength longer than the wavelength of the excitation light as incident light incident on the ps separation film;
A blue laser beam having a polarization component between the p-polarization plane and the s-polarization plane by emitting a laser beam having a predetermined wavelength below the blue wavelength range and irradiating the phosphor with the excitation light. A light source device capable of irradiating the ps separation film as the incident light,
A projector comprising: an image generating element that generates an image using light emitted from the light source device.
(9) a polarization conversion element having a ps separation film capable of separating a polarization component of incident light into a p-polarization component and an s-polarization component;
A phosphor capable of irradiating visible light having a wavelength longer than the wavelength of the excitation light, which is generated by being excited by excitation light, as the incident light incident on the ps separation film;
A plurality of laser beams emitted from the phosphors are incident on the ps separation film by emitting laser light in a predetermined wavelength region as the excitation light and irradiating the phosphors with the excitation light. A plurality of light source elements that can be irradiated as light;
A combined vector direction obtained by combining vector directions along the polarization planes of the plurality of incident lights when viewed in the optical axis direction is a polarization plane of the p-polarized light and a polarization plane of the s-polarized light when viewed in the optical axis direction. A light source device having a support member that supports the plurality of light source elements,
A projector comprising: an image generating element that generates an image using light emitted from the light source device.

DESCRIPTION OF SYMBOLS 1,101 ... Light source device 2,201,202 ... Laser light source 5,95 ... Polarization conversion element 11 ... ps separation film 20 ... Support substrate 32 ... Phosphor layer 100 ... Projector 400R, 400G and 400B ... Liquid crystal light valve

Claims (4)

A solid-state light source element that has a pair of electrodes and emits excitation light having a polarization plane along the arrangement direction of the pair of electrodes;
A support member that supports the solid-state light source element so that the pair of electrodes are arranged in a predetermined direction;
A rotating substrate that transmits the excitation light;
A plurality of transparent substrates arranged in a direction different from the predetermined direction and in a non-orthogonal direction with respect to the predetermined direction within a plane perpendicular to the incident direction of transmitted light transmitted through the rotating substrate; A projector comprising: a polarization conversion element provided between a plurality of transparent substrates and having a ps separation film capable of separating a polarization component of the transmitted light into a p-polarization component and an s-polarization component. The projector according to claim 1,
The rotating substrate is a phosphor wheel. The projector according to claim 1,
The plurality of transparent substrates are composed of a plurality of first substrates and a plurality of second substrates, and the first substrates and the second substrates are alternately arranged,
The first substrate is
An incident side end face on which the transmitted light is incident;
A first surface provided with the ps separation film and inclined at a predetermined angle with respect to the incident side end surface;
An exit-side end face provided parallel to the entrance-side end face;
A second surface provided in parallel to the first surface,
The second substrate is
An incident side end face on which the transmitted light is incident;
A third surface provided to be inclined at the predetermined angle with respect to the incident side end surface;
An exit-side end face provided parallel to the entrance-side end face;
A fourth surface provided in parallel to the third surface,
The first surface of the first substrate and the fourth surface of the second substrate are connected via the ps separation film,
The projector, wherein the second surface of the first substrate and the third surface of the second substrate are connected via a total reflection film. The projector according to claim 2,
The solid-state light source element generates excitation light from a violet wavelength region to a blue wavelength region,
The phosphor of the phosphor wheel emits linearly polarized light in a state where the polarization plane of the excitation light in the violet wavelength region to the blue wavelength region is maintained as the transmitted light.