Optical element, light source device and projector

Abstract

The purpose of the present invention is to provide: an optical element that can increase the color gamut of images and improve the brightness of images; a light source device comprising said optical element; and a projector comprising said light source device.　Provided are: an optical element that comprises a first color conversion layer, a second color conversion layer, and a heat-insulating layer, the heat-insulating layer being disposed between the first color conversion layer and the second color conversion layer; a light source device comprising said optical element; and a projector comprising said light source device.

Description

[Technical field]

[0001] The present technology relates to an optical element, a light source device, and a projector. [Background technology]

[0002] In recent years, there has been an increasing demand for projectors for movie viewing and presentations at meetings, etc., and there is currently a demand for bright images with a wide color gamut.

[0003] For example, a technique has been proposed relating to a wavelength conversion element having a two-layer structure using two phosphors, as well as a light source device and a projector including the wavelength conversion element (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-36457 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technique proposed in Patent Document 1 may not be able to obtain bright images with a wide color gamut.

[0006] Therefore, the present technology has been developed in consideration of such circumstances, and has as its main objective to provide an optical element that can realize a wider color gamut and improved brightness of an image, as well as a light source device including the optical element and a projector including the light source device. [Means for solving the problem]

[0007] The inventors of the present invention have conducted intensive research to achieve the above-mentioned object, and as a result, have surprisingly succeeded in realizing a wider color gamut and improved brightness of images, thereby completing the present technology.

[0008] That is, as a first aspect of the present technology, An optical element is provided, comprising a first color conversion layer, a second color conversion layer, and a heat insulating layer, the heat insulating layer being disposed between the first color conversion layer and the second color conversion layer.

[0009] In the optical element according to the present technology, The heat insulating layer may be optically transparent.

[0010] In the optical element according to the present technology, The heat insulating layer may include a material having optical transparency.

[0011] In the optical element according to the present technology, At least one of the first color conversion layer and the second color conversion layer may have an uneven portion, The first color conversion layer and the second color conversion layer may be joined via the protrusion to form the heat insulating layer.

[0012] In the optical element according to the present technology, At least one of the first color conversion layer and the second color conversion layer may have a recess, The first color conversion layer and the second color conversion layer may be joined via the recess to form the heat insulating layer.

[0013] In the optical element according to the present technology, The first color conversion layer and the second color conversion layer may be bonded to each other via a bonding layer.

[0014] In the optical element according to the present technology, The bonding layer may have heat insulating properties.

[0015] In the optical element according to the present technology, The attachment layer may include beads.

[0016] The optical element according to the present technology may further include a first substrate, The first substrate may be thermally conductive; The heat insulating layer and the first substrate may be disposed opposite each other with the first color conversion layer interposed therebetween.

[0017] In the optical element according to the present technology, The first substrate may be light reflective.

[0018] In the optical element according to the present technology, The first substrate may be optically transparent.

[0019] In the optical element according to the present technology, The first substrate may include a light-transmitting region and a light-reflective region.

[0020] In the optical element according to the present technology, The second color conversion layer and the first substrate may be bonded via a first bonding member, The first joint member may be thermally conductive.

[0021] In the optical element according to the present technology, The first bonding member and the first substrate may be bonded via a second bonding member, The second bonding member may have thermal insulation properties.

[0022] In the optical element according to the present technology, The first substrate may have a recess on the heat insulating layer side, The first color conversion layer may be embedded in the recess.

[0023] The optical element according to the present technology may further include a second substrate, The second substrate may be thermally conductive; The heat insulating layer and the second substrate may be disposed opposite each other with the second color conversion layer interposed therebetween.

[0024] In the optical element according to the present technology, The second substrate may be optically transparent.

[0025] In the optical element according to the present technology, The second substrate may include a light-transmitting region and a light-reflective region.

[0026] The second aspect of this technology is as follows: An optical element according to a first aspect of the present technology; A light source that emits excitation light; and a moving mechanism for moving the irradiation position of the excitation light on the optical element over time.

[0027] Furthermore, the third aspect of this technology is as follows: A light source device according to a second aspect of the present technology; The present invention provides a projector including: an image projection device that generates a predetermined image light by using the light emitted from the light source device, and projects the generated image light to the outside.

[0028] According to the present technology, it is possible to provide an optical element capable of realizing a wider color gamut of an image and an improved brightness of the image, as well as a light source device including the optical element and a projector including the light source device. Note that the effects described here are not necessarily limited to those described in the present disclosure, and may be any of the effects described in the present disclosure. [Brief description of the drawings]

[0029] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of an optical element according to a first embodiment to which the present technology is applied. [Diagram 2] FIG. 2 is a diagram showing a configuration example of an optical element according to a second embodiment to which the present technology is applied. [Diagram 3] FIG. 3 is a diagram showing a configuration example of an optical element according to a third embodiment to which the present technology is applied. [Figure 4] FIG. 4 is a diagram showing a configuration example of an optical element according to a third embodiment to which the present technology is applied. [Diagram 5]FIG. 5 is a diagram showing a configuration example of an optical element according to a fourth embodiment to which the present technology is applied. [Figure 6] FIG. 6 is a diagram showing a configuration example of an optical element according to a fifth embodiment to which the present technology is applied. [Figure 7] FIG. 7 is a diagram showing a configuration example of an optical element according to a fifth embodiment to which the present technology is applied. [Figure 8] FIG. 8 is a diagram showing a configuration example of an optical element according to a sixth embodiment to which the present technology is applied. [Figure 9] FIG. 9 is a diagram showing an example of the configuration of a light source device according to the seventh embodiment to which the present technology is applied. [Figure 10] FIG. 10 is a diagram showing an example of the configuration of a light source device according to an eighth embodiment to which the present technology is applied. [Figure 11] FIG. 11 is a diagram showing an example of the configuration of a projector according to the ninth embodiment to which the present technology is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] A preferred embodiment for implementing the present technology will be described below. The embodiment described below shows an example of a typical embodiment of the present technology, and the scope of the present technology will not be narrowly interpreted by this. Unless otherwise specified, in the drawings, "upper" means the upper direction or upper side in the drawing, "lower" means the lower direction or lower side in the drawing, "left" means the left direction or left side in the drawing, and "right" means the right direction or right side in the drawing. In addition, in the drawings, the same or equivalent elements or members are given the same reference numerals, and duplicated explanations are omitted.

[0031] The explanation will be given in the following order. 1. Overview of this technology 2. First embodiment (optical element example 1) 3. Second embodiment (optical element example 2) 4. Third embodiment (optical element example 3) 5. Fourth embodiment (optical element example 4) 6. Fifth embodiment (optical element example 5) 7. Sixth embodiment (optical element example 6) 8. Seventh embodiment (example 1 of light source device) 9. Eighth embodiment (example 2 of light source device) 10. Ninth embodiment (example of projector)

[0032] 1. Overview of this technology First, an overview of the present technology will be described. The present technology relates to an optical element, a light source device, and a projector.

[0033] In light sources that use color conversion by phosphors or the like, one method of compensating for colors that are lacking in the emission spectrum of a single material is to use a technology that makes the color conversion layer have a two-layer structure.

[0034] In the two-layer structure of this technology, the two color conversion layers are in direct contact with each other. However, in this case, since the heat of each layer is transferred between them, the effect of heat transfer is large, especially for materials with high sensitivity to efficiency changes with temperature, and there is a risk of a significant decrease in conversion efficiency. Examples of materials with high efficiency conversion sensitivity with temperature include quantum dots. This technology is a two-layer structure having a layer using quantum dots and a layer using a phosphor, and has a heat insulating layer between the two layers. Furthermore, in this technology, each layer of the two-layer structure may be formed with a substrate that transports heat and dissipates heat. By using a two-layer structure, heat transfer between the layers can be suppressed, and each layer can be effectively cooled. As a result, this technology can improve the light emission efficiency of the optical element, and can also realize a miniaturized light source and high brightness, and can further realize a wide color gamut of the image and an improvement in the brightness of the image.

[0035] Hereinafter, preferred embodiments for carrying out the present technology will be described with reference to the drawings. The embodiments described below are examples of typical embodiments of the present technology, and the scope of the present technology is not to be interpreted narrowly by these embodiments.

[0036] 2. First embodiment (example 1 of optical element) An optical element according to a first embodiment (example 1 of optical element) of the present technology will be described with reference to Fig. 1. Fig. 1 is a diagram showing a configuration example of the optical element according to the first embodiment of the present technology, and more specifically, Fig. 1 is a cross-sectional view of an optical element 100 of the first embodiment.

[0037] The optical element 100 shown in FIG. 1 includes a first color conversion layer 5, a second color conversion layer 2, and a heat insulating layer 3, and the heat insulating layer 3 is disposed between the first color conversion layer 5 and the second color conversion layer 2. That is, the first color conversion layer 5 and the second color conversion layer 2 are made to face each other, and the heat insulating layer 3 is provided between the first color conversion layer 5 and the second color conversion layer 2. The first color conversion layer 5 uses a light emitting material with a small excitation density and a large temperature dependency. The first color conversion layer 5 is, for example, a layer in which red quantum dot (QD) powder is mixed into a resin. Examples of red quantum dots include CdSe / ZnS and InP / ZnS. The second color conversion layer 2 is, for example, a layer in which YAG (Yttrium Aluminum Garnet) phosphor powder is mixed into a resin.

[0038] The heat insulating layer 3 is preferably optically transparent in order to excite the first color conversion layer 5. The heat insulating layer 3 is, for example, an air layer, and the height of the heat insulating layer 3 (also called a gap; the length in the vertical direction in FIG. 1) may be arbitrary, for example, 1 to 500 μm, and about 10 μm may be appropriate. By having the heat insulating layer 3, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by disposing the heat insulating layer 3, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, and to separate the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2 (X mark F in FIG. 1).

[0039] The optical element 100 shown in Fig. 1 further includes a first substrate 6. The first substrate 6 is a base substrate and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in Fig. 1, the heat insulating layer 3 and the first substrate 6 are disposed opposite each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat P2 generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 100 as shown by the arrow S12, thereby suppressing the temperature rise of the first color conversion layer 5.

[0040] The optical element 100 shown in Fig. 1 further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in Fig. 1, the heat insulating layer 3 and the second substrate 1 are disposed opposite to each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat P1 generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 100 as shown by the arrow S11, thereby suppressing a temperature rise in the second color conversion layer 2.

[0041] As shown in FIG. 1, the first color conversion layer 5 and the second color conversion layer 2 are bonded via a bonding layer 4. The bonding layer 4 is formed in substantially the same layer as the heat insulating layer 3. The bonding layer 4 may or may not have heat insulating properties, but it is preferable that the bonding layer 4 has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other. The bonding layer 4 having heat insulating properties may be referred to as a heat insulating bonding layer 4 (hereinafter the same).

[0042] The following describes examples of the effects and operations of the optical element 100. Unless there is any particular technical contradiction, the examples of the effects and operations of the optical element 100 (the optical element of the first embodiment) can be applied to the optical elements of the second to fourth and sixth embodiments of the present technology described below.

[0043] The excitation light Bs passes through the second substrate 1 and excites the second color conversion layer 2. The second substrate 1 is, for example, a heat transport substrate, which may be transparent, and may have a structure with holes in the excitation area.

[0044] The excited second color conversion layer 2 emits light. A part of this emitted light passes through the second substrate 1 (heat transport substrate) and is output to the outside of the optical element 100 (two-layer structure device) (Y: yellow light).

[0045] A part of the fluorescence emitted from the second color conversion layer 2 and / or a part of the excitation light Bs transmitted through the second color conversion layer 2 passes through the heat insulating layer 3 and excites the first color conversion layer 5. The heat insulating layer must be a transparent medium.

[0046] The excited first color conversion layer 5 emits light. A part of this emitted light passes through the heat insulating layer 3, the second color conversion layer 2, and the first substrate 1 (heat transport substrate), and is output to the outside of the optical element 100 (two-layer structure device) (R: red light). The remaining emitted light is reflected by the first substrate 6 (for example, a base substrate), passes through the first color conversion layer 5, the heat insulating layer 3, the second color conversion layer 2, and the second substrate 1 (heat transport substrate), and is output to the outside of the optical element 100 (R: red light). A reflective film may be added to the surface (surface on the first color conversion layer 5 side) of the first substrate 6 (base substrate), which further improves the light utilization efficiency.

[0047] The light output from the optical element 100 is extracted by a lens to the outside of the light source and is incident on an optical system such as an illumination system for use.

[0048] According to the first embodiment (optical element example 1) of the present technology, the thermal insulation between the two layers (between the first color conversion layer 5 and the second color conversion layer 2) can suppress the temperature rise between the first color conversion layer 5 and the second color conversion layer 2, and in particular, it is possible to suppress temperature quenching of the light emission of the first color conversion layer 5, achieve high light emission efficiency, realize the miniaturization of the light source by improving the light emission efficiency, and suppress quantum dot (QD) degradation during manufacturing.

[0049] The above description of the optical element of the first embodiment (example 1 of optical element) of the present technology can be applied to the optical elements of the second to sixth embodiments of the present technology described below, unless there is any particular technical contradiction.

[0050] 3. Second embodiment (optical element example 2) An optical element according to a second embodiment (example 2 of optical element) of the present technology will be described with reference to Fig. 2. Fig. 2 is a diagram showing a configuration example of an optical element according to a second embodiment of the present technology, and more specifically, Fig. 2(a) is a cross-sectional view of an optical element 200a of the second embodiment, and Fig. 2(b) is a cross-sectional view of an optical element 200b of the second embodiment.

[0051] The optical element 200a shown in Figure 2(a) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-2a, with the thermal insulation layer 3-2a being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0052] The heat insulating layer 3-2a is formed by bonding the first color conversion layer 5 and the second color conversion layer 2 via a plurality of convex portions 5t of the first color conversion layer 5 and convex portions 2t of the second color conversion layer 2. To form the heat insulating layer 3-2a, either the first color conversion layer 5 or the second color conversion layer 2 may have convex portions, and the bonding surface of at least either the first color conversion layer 5 or the second color conversion layer 2 may be a rough surface (e.g., Ra of 100 nm or more).

[0053] The heat insulating layer 3-2a is preferably light-transmitting so as to excite the first color conversion layer 5. The heat insulating layer 3-2a is, for example, an air layer, and the height of the heat insulating layer 3-2a (also called a gap; the length in the vertical direction in FIG. 2(a)) may be arbitrary, for example, 1 to 500 μm, and may be about 10 μm. By providing the heat insulating layer 3-2a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by providing the heat insulating layer 3-2a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, thereby separating the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0054] The optical element 200a shown in FIG. 2(a) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 2(a), the heat insulating layer 3-2a and the first substrate 6 are disposed opposite each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 200a, thereby suppressing a temperature rise in the first color conversion layer 5.

[0055] The optical element 200a shown in FIG. 2(a) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 2(a), the heat insulating layer 3-2a and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 200a, thereby suppressing the temperature rise of the second color conversion layer 2.

[0056] The optical element 200a does not have a bonding layer for bonding the first color conversion layer 5 and the second color conversion layer 2, but may have the bonding layer 4 shown in the first embodiment section above.

[0057] The optical element 200b shown in Figure 2(b) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-2b, with the thermal insulation layer 3-2b being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0058] The heat insulating layer 3-2b is formed by bonding the first color conversion layer 5 and the second color conversion layer 2 via a recess 5-2b in the first color conversion layer 5. The recess 5-2b is preferably formed in a region where the first color conversion layer 5 and the second color conversion layer 2 generate heat by light emission. Although not shown, in order to form the heat insulating layer 3-2b, the second color conversion layer 2 may have a recess, or both the first color conversion layer 5 and the second color conversion layer 2 may have a protrusion.

[0059] The heat insulating layer 3-2b is preferably light-transmitting so as to excite the first color conversion layer 5. The heat insulating layer 3-2b is, for example, an air layer, and the height of the heat insulating layer 3-2b (also called a gap; the length in the vertical direction in FIG. 2(b)) may be arbitrary, for example, 1 to 500 μm, and may be about 10 μm. By providing the heat insulating layer 3-2b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by providing the heat insulating layer 3-2b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, thereby separating the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0060] The optical element 200b shown in FIG. 2(b) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 2(b), the heat insulating layer 3-2b and the first substrate 6 are disposed opposite each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 200b, thereby suppressing a temperature rise in the first color conversion layer 5.

[0061] The optical element 200b shown in FIG. 2(b) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 2(b), the heat insulating layer 3-2b and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 200b, thereby suppressing the temperature rise of the second color conversion layer 2.

[0062] According to the second embodiment (optical element example 2) of the present technology, the thermal insulation between the two layers (between the first color conversion layer 5 and the second color conversion layer 2) can suppress the temperature rise between the first color conversion layer 5 and the second color conversion layer 2, and in particular, it is possible to suppress temperature quenching of the light emission of the first color conversion layer 5, achieve high light emission efficiency, realize the miniaturization of the light source by improving the light emission efficiency, and suppress quantum dot (QD) degradation during manufacturing.

[0063] What has been described above about the optical element of the second embodiment (optical element example 2) of the present technology can be applied to the optical element of the first embodiment of the present technology described above and the optical elements of the third to sixth embodiments of the present technology described below, unless there is any particular technical contradiction.

[0064] 4. Third embodiment (optical element example 3) An optical element according to a third embodiment (example 3 of optical element) of the present technology will be described with reference to Fig. 3 and Fig. 4. Fig. 3 is a diagram showing a configuration example of an optical element according to a third embodiment of the present technology, more specifically, Fig. 3(a) is a cross-sectional view of an optical element 300a of the third embodiment, and Fig. 3(b) is a cross-sectional view of an optical element 300b of the third embodiment. Fig. 4 is a diagram showing a configuration example of an optical element according to a third embodiment of the present technology, more specifically, Fig. 4(a) is a cross-sectional view of an optical element 400a of the third embodiment, and Fig. 4(b) is a cross-sectional view of an optical element 400b of the third embodiment.

[0065] The optical element 300a shown in Figure 3(a) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-3a, with the thermal insulation layer 3-3a being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0066] The heat insulating layer 3-3a is preferably light-transmitting so as to excite the first color conversion layer 5. The heat insulating layer 3-3a is, for example, an air layer, and the height of the heat insulating layer 3-3a (also called a gap; the length in the vertical direction in FIG. 3(a)) may be arbitrary, for example, 1 to 500 μm, and may be about 10 μm. By providing the heat insulating layer 3-3a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by providing the heat insulating layer 3-3a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, thereby separating the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0067] The optical element 300a shown in FIG. 3(a) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 3(a), the heat insulating layer 3-3a and the first substrate 6 are disposed opposite each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 300a, thereby suppressing a temperature rise in the first color conversion layer 5.

[0068] The optical element 300a shown in FIG. 3(a) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 3(a), the heat insulating layer 3-3a and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 300a, thereby suppressing a temperature rise in the second color conversion layer 2.

[0069] As shown in Fig. 3(a), the first color conversion layer 5 and the second color conversion layer 2 are bonded via a bonding layer 4. The bonding layer 4 is formed in substantially the same layer as the heat insulating layer 3-3a. The bonding layer 4 may or may not have heat insulating properties, but it is preferable that the bonding layer 4 has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other.

[0070] The bonding layer 4 contains beads 21. The beads 21 may or may not have thermal insulation properties, but preferably have thermal insulation properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other. The height (length in the vertical direction in FIG. 3(a)) of the thermal insulation layer 3-3a (e.g., air layer or gap) can be adjusted by the bead diameter, so that the height of the thermal insulation layer 3-3a (e.g., air layer or gap) can be accurately adjusted and the thermal insulation layer 3-3a (e.g., air layer or gap) can be easily manufactured.

[0071] The optical element 300b shown in Figure 3(b) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-3b, with the thermal insulation layer 3-3b being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0072] The heat insulating layer 3-3b is preferably light transmissive in order to excite the first color conversion layer 5. The heat insulating layer 3-3b is, for example, an air layer, and the height of the heat insulating layer 3-3b (also called a gap; the length in the vertical direction in FIG. 3(b)) may be arbitrary, for example, 1 to 500 μm, and may be about 10 μm. By providing the heat insulating layer 3-3b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by providing the heat insulating layer 3-3b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, thereby separating the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0073] The optical element 300b shown in FIG. 3(b) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 3(b), the heat insulating layer 3-3b and the first substrate 6 are disposed opposite each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 300b, thereby suppressing a temperature rise in the first color conversion layer 5.

[0074] The optical element 300b shown in FIG. 3(b) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 3(b), the heat insulating layer 3-3b and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 300b, thereby suppressing a temperature rise in the second color conversion layer 2.

[0075] As shown in FIG. 3(b), the first color conversion layer 5 and the second color conversion layer 2 are bonded via a bonding layer 4-3b. The bonding layer 4-3b is formed in substantially the same layer (substantially the same layer) as the heat insulating layer 3-3b. The bonding layer 4-3b may or may not have heat insulating properties, but it is preferable that the bonding layer 4-3b has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other. The bonding layer 4-3b contains a thermally expandable material, and the bonding layer 4-3b expands in the vertical direction in FIG. 3(b) due to heat, forming the heat insulating layer 3-3b consisting of an air layer.

[0076] The optical element 400a shown in Figure 4(a) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-4a, with the thermal insulation layer 3-4a being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0077] The heat insulating layer 3-4a is preferably optically transparent in order to excite the first color conversion layer 5. The heat insulating layer 3-4a is, for example, an air layer. The height of the heat insulating layer 3-4a (also called the gap, which is the length in the vertical direction in FIG. 4(a)), i.e., the length from the lower side of the second color conversion layer 2 to the upper side of the first color conversion layer 5 in the heat insulating layer 3-4a, may be arbitrary, but may be, for example, 1 to 500 μm, and may be about 10 μm. By having the heat insulating layer 3-4a, it is possible to prevent the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 from moving to each other. In other words, by providing the insulating layer 3-4a, the heat generated in the first color conversion layer 5 is prevented from transferring to the second color conversion layer 2, and the heat generated in the second color conversion layer 2 is prevented from transferring to the first color conversion layer 5, thereby separating the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0078] 4(a), the heat insulating layer 3-4a is formed on the outside of the left side, upper side, and right side of the first color conversion layer 5. In other words, the first color conversion layer 5 is disposed so as to be buried in the heat insulating layer 304a. This arrangement of the heat insulating layer 3-4a further suppresses the transfer of heat generated in the first color conversion layer 5 to the second color conversion layer 2.

[0079] The optical element 400a shown in FIG. 4(a) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 4(a), the heat insulating layer 3-4a and the first substrate 6 are disposed opposite each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 400a, thereby suppressing the temperature rise of the first color conversion layer 5.

[0080] The optical element 400a shown in FIG. 4(a) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 4(a), the heat insulating layer 3-4a and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 400a, thereby suppressing the temperature rise of the second color conversion layer 2.

[0081] In the optical element 400a, the second color conversion layer 2 and the first bonding member 6-4a-1 are bonded, the first bonding member 6-4a-1 and the second bonding member 4-4a are bonded, and the second bonding member 4-4a and the first substrate 6 are bonded. The first bonding member 6-4a-1 has thermal conductivity, and the heat generated in the second color conversion layer 2 simultaneously with light emission is also transmitted to the first bonding member 6-4a-1 and released to the outside of the optical element 400a, so that the temperature rise of the second color conversion layer 2 can be further suppressed. The second bonding member 4-4a has thermal insulation properties, and the second bonding member 4-4a can block the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 from passing back and forth between them. In addition, the second color conversion layer 2 and the first bonding member 6-4a-1 may be directly bonded together without using the second bonding member 4-4a (i.e., the second color conversion layer 2 and the first substrate 6 may be bonded together via the first bonding member 6-4a-1 without using the second bonding member 4-4a), thereby merging the heat exhaust path of the first color conversion layer 5 and the heat exhaust path of the second color conversion layer 2.

[0082] The optical element 400b shown in Figure 4(b) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-4b, with the thermal insulation layer 3-4b being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0083] The heat insulating layer 3-4b is preferably light-transmitting so as to excite the first color conversion layer 5. The heat insulating layer 3-4b is, for example, an air layer, and the height of the heat insulating layer 3-4b (also called a gap; the length in the vertical direction in FIG. 4(b)) may be arbitrary, for example, 1 to 500 μm, and may be about 10 μm. By providing the heat insulating layer 3-4b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by providing the heat insulating layer 3-4b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, thereby separating the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0084] The heat insulating layer 3-4b contains beads 22. The beads 22 may be made of a material having optical transparency, such as glass. By using optically transparent beads, light scattering increases, improving light utilization efficiency. The beads 22 may be hollow beads having optical transparency, and by using hollow beads, heat insulation is further improved. Note that the heat insulating layer 3-4b is not limited to containing the beads 22, and may contain any material having optical transparency, such as a layer filled with glass.

[0085] The optical element 400b shown in FIG. 4(b) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 4(b), the heat insulating layer 3-4b and the first substrate 6 are disposed opposite to each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 400b, thereby suppressing a temperature rise in the first color conversion layer 5.

[0086] The optical element 400b shown in FIG. 4(b) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 4(b), the heat insulating layer 3-4b and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 400b, thereby suppressing the temperature rise of the second color conversion layer 2.

[0087] As shown in FIG. 4(b), the first color conversion layer 5 and the second color conversion layer 2 are bonded via a bonding layer 4-4b. The first substrate 6 and the second substrate 1 are bonded via a bonding layer 4-4b. That is, the first color conversion layer 5 and the second color conversion layer 2 are formed surrounded by the first substrate 6, the second substrate 1, and the bonding layer 4-4b. The bonding layer 4-4b may or may not have thermal insulation properties, but it is preferable that the bonding layer 4-4b has thermal insulation properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other.

[0088] According to the third embodiment (optical element example 3) of the present technology, the thermal insulation between the two layers (between the first color conversion layer 5 and the second color conversion layer 2) can suppress the temperature rise between the first color conversion layer 5 and the second color conversion layer 2, and in particular, it is possible to suppress temperature quenching of the light emission of the first color conversion layer 5, achieve high light emission efficiency, realize the miniaturization of the light source by improving the light emission efficiency, and suppress quantum dot (QD) degradation during manufacturing.

[0089] What has been described above about the optical element of the third embodiment (optical element example 3) of the present technology can be applied to the optical elements of the first and second embodiments of the present technology described above and the optical elements of the fourth to sixth embodiments of the present technology described below, unless there is any particular technical contradiction.

[0090] 5. Fourth embodiment (optical element example 4) An optical element according to a fourth embodiment (optical element example 4) of the present technology will be described with reference to Fig. 5. Fig. 5 is a diagram showing a configuration example of an optical element according to a fourth embodiment of the present technology, and more specifically, Fig. 5(a) is a cross-sectional view of an optical element 500a of the fourth embodiment, Fig. 5(b) is a cross-sectional view of an optical element 500b of the fourth embodiment, and Fig. 5(c) is a cross-sectional view of an optical element 500c of the fourth embodiment.

[0091] The optical element 500a shown in Figure 5(a) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-5a, with the thermal insulation layer 3-5a being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0092] The heat insulating layer 3-5a is preferably light-transmitting so as to excite the first color conversion layer 5. The heat insulating layer 3-5a is, for example, an air layer, and the height of the heat insulating layer 3-5a (also called a gap; the length in the vertical direction in FIG. 5(a)) may be arbitrary, for example, 1 to 500 μm, and may be about 10 μm. By providing the heat insulating layer 3-5a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by providing the heat insulating layer 3-5a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, thereby separating the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0093] The optical element 500a shown in FIG. 5(a) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 5(a), the first substrate 6 has a recess 6-5a, and the first color conversion layer 5 is formed so as to be embedded in the recess 6-5a, and the heat insulating layer 3-5a and the first substrate 6 are disposed opposite to each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 at the same time as light emission is propagated through the first substrate 6 and released to the outside of the optical element 500a, thereby suppressing the temperature rise of the first color conversion layer 5. Furthermore, since the first color conversion layer 5 is embedded in the first substrate 6, not only heat from below the first color conversion layer 5 (the bottom edge of the first color conversion layer 5) but also heat from the left (the left edge of the first color conversion layer 5) and the right (the right edge of the first color conversion layer 5) propagates through the first substrate 6 and is released outside the optical element 500a, further suppressing the temperature rise of the first color conversion layer 5.

[0094] The optical element 500a shown in FIG. 5(a) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 5(a), the heat insulating layer 3-5a and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 500a, thereby suppressing the temperature rise of the second color conversion layer 2.

[0095] As shown in Fig. 5(a), a first substrate (e.g., a base substrate) 6 and a second color conversion layer 2 are bonded via a bonding layer 4. The bonding layer 4 is formed in substantially the same layer as the heat insulating layer 3-5a. The bonding layer 4 may or may not have heat insulating properties, but it is preferable that the bonding layer 4 has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other.

[0096] The optical element 500b shown in Figure 5(b) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-5b, with the thermal insulation layer 3-5b being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0097] The heat insulating layer 3-5b is preferably light-transmitting so as to excite the first color conversion layer 5. The heat insulating layer 3-5b is, for example, an air layer, and the height of the heat insulating layer 3-5b (also called a gap; the length in the vertical direction in FIG. 5(b)) may be arbitrary, for example, 1 to 500 μm, and may be about 10 μm. By providing the heat insulating layer 3-5b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by providing the heat insulating layer 3-5b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, thereby separating the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0098] The optical element 500b shown in FIG. 5(b) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 5(b), the heat insulating layer 3-5b and the first substrate 6 are disposed opposite to each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 500b as shown by the arrows S53b and 54b, thereby suppressing the temperature rise of the first color conversion layer 5.

[0099] The optical element 500b shown in FIG. 5(b) further includes a second substrate 1 (1-5). The second substrate 1 (1-5) is composed of a light-transmitting region 1-5b, a light-reflective region 1-50b-1, and a light-reflective region 1-50b-2. A heat transport substrate is formed in the light-transmitting region 1-5b, a base substrate is formed in the light-reflective region 1-50b-1, and a base substrate is formed in the light-reflective region 1-50b-2. The heat transport substrate formed in the light-transmitting region 1-5b is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the heat transport substrate. As shown in FIG. 5(b), the heat insulating layer 3-5b and the second substrate 1 are arranged opposite to each other with a second color conversion layer 2 interposed therebetween. The second substrate 1 has thermal conductivity, and the heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the light-transmitting region 1-5b and the light-reflective region 1-50b-2 of the second substrate 1 as shown by the arrows S51b and S52b, and is released to the outside of the optical element 500b, thereby suppressing the temperature rise of the second color conversion layer 2. The second substrate 1 in FIG. 5(b) has a light-transmitting region and a light-reflective region, and can further improve the heat transport property (heat dissipation property) while transmitting light to the second color conversion layer. Note that the first substrate 6 may also have a light-transmitting region and a light-reflective region, as long as the optical element 500b can ensure the function of a reflective optical element.

[0100] As shown in Fig. 5(b), the first color conversion layer 5 and the second color conversion layer 2 are bonded via a bonding layer 4. The bonding layer 4 is formed in substantially the same layer as the heat insulating layer 3-5b. The bonding layer 4 may or may not have heat insulating properties, but it is preferable that the bonding layer 4 has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other.

[0101] The optical element 500c shown in Figure 5(c) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-5c, with the thermal insulation layer 3-5c being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0102] The heat insulating layer 3-5c is preferably light-transmitting in order to excite the first color conversion layer 5. The heat insulating layer 3-5c is, for example, an air layer, and the height of the heat insulating layer 3-5c (also called a gap; the length in the vertical direction in FIG. 5(c)) may be arbitrary, for example, 1 to 500 μm, and about 10 μm may be appropriate. By having the heat insulating layer 3-5c, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by disposing the heat insulating layer 3-5c, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, and to separate the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0103] The optical element 500c shown in FIG. 5(c) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 5(c), the heat insulating layer 3-5c and the first substrate 6 are disposed opposite to each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 500c, thereby suppressing a temperature rise in the first color conversion layer 5.

[0104] The optical element 500c shown in FIG. 5(c) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 5(c), the heat insulating layer 3-5c and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 500c, thereby suppressing the temperature rise of the second color conversion layer 2.

[0105] 5(c), an opening K5c-1 is formed penetrating the first substrate 6 and the first color conversion layer 5 to reach the heat insulating layer 3-5c, and an opening K5c-2 is formed penetrating the second substrate 1 and the second color conversion layer 2 to reach the heat insulating layer 3-5c. By forming the openings K5c-1 and K5c-2, outside air flows through the heat insulating layer 3-5c, and if the heat insulating layer 3-5c is an air layer, the air in the heat insulating layer 3-5c is refreshed, improving the heat insulating properties.

[0106] As shown in Fig. 5(c), the first color conversion layer 5 and the second color conversion layer 2 are bonded via a bonding layer 4. The bonding layer 4 is formed in substantially the same layer as the heat insulating layer 3-5c. The bonding layer 4 may or may not have heat insulating properties, but it is preferable that the bonding layer 4 has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other.

[0107] According to the fourth embodiment (optical element example 4) of the present technology, the thermal insulation between the two layers (between the first color conversion layer 5 and the second color conversion layer 2) can suppress the temperature rise between the first color conversion layer 5 and the second color conversion layer 2, and in particular, it is possible to suppress temperature quenching of the light emission of the first color conversion layer 5, achieve high light emission efficiency, realize the miniaturization of the light source by improving the light emission efficiency, and suppress quantum dot (QD) degradation during manufacturing.

[0108] What has been described above about the optical element of the fourth embodiment (optical element example 4) of the present technology can be applied to the optical elements of the first to third embodiments of the present technology described above and the optical elements of the fifth and sixth embodiments of the present technology described below, unless there is any particular technical contradiction.

[0109] 6. Fifth embodiment (optical element example 5) The optical element according to the fifth embodiment (example 5 of the optical element) of the present technology is a transmissive optical element. Details will be described with reference to Figs. 6 and 7. Fig. 6 is a diagram showing a configuration example of the optical element according to the fifth embodiment of the present technology, more specifically, Fig. 6(a) is a cross-sectional view of the optical element 600a of the fifth embodiment, and Fig. 6(b) is a cross-sectional view of the optical element 600b of the fifth embodiment. Fig. 7 is a diagram showing a configuration example of the optical element according to the fifth embodiment of the present technology, more specifically, Fig. 7(a) is a cross-sectional view of the optical element 700a of the fifth embodiment, and Fig. 7(b) is a cross-sectional view of the optical element 700b of the fifth embodiment.

[0110] The optical element 600a shown in Figure 6(a) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-6a, with the thermal insulation layer 3-6a being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0111] The heat insulating layer 3-6a is preferably light-transmitting so as to excite the first color conversion layer 5. The heat insulating layer 3-6a is, for example, an air layer, and the height of the heat insulating layer 3-6a (also called a gap; the length in the vertical direction in FIG. 6(a)) may be arbitrary, for example, 1 to 500 μm, and may be about 10 μm. By providing the heat insulating layer 3-6a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by providing the heat insulating layer 3-6a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, thereby separating the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0112] The optical element 600a shown in Fig. 6(a) further includes a first substrate 11. The first substrate 11 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the first substrate 11. As shown in Fig. 6(a), the heat insulating layer 3-6a and the first substrate 11 are disposed opposite to each other via the first color conversion layer 5. The first substrate 11 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 11 and released to the outside of the optical element 600a, thereby suppressing a temperature rise in the first color conversion layer 5.

[0113] The optical element 600a shown in FIG. 6(a) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 6(a), the heat insulating layer 3-6a and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 600a, thereby suppressing the temperature rise of the second color conversion layer 2.

[0114] As shown in Fig. 6(a), the first color conversion layer 5 and the second color conversion layer 2 are bonded via a bonding layer 4. The bonding layer 4 is formed in substantially the same layer as the heat insulating layer 3-6a. The bonding layer 4 may or may not have heat insulating properties, but it is preferable that the bonding layer 4 has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other.

[0115] An example of the function and operation of the optical element 600a will be described. Note that unless there is any particular technical contradiction, the example of the function and operation of the optical element 600a can be applied to the optical elements 600b, 700a, and 700b described later.

[0116] The excitation light Bs passes through the second substrate 1 and excites the second color conversion layer 2. The second substrate 1 is, for example, a heat transport substrate, and may be transparent or may have a structure with holes in the excitation area. The first substrate 11 is also, for example, a heat transport substrate, and may be transparent or may have a structure with holes in the excitation area.

[0117] The excited second color conversion layer 2 emits light. A part of this light passes through the heat insulating layer 3-6a, the first color conversion layer 5, and the first substrate 11 (heat transport substrate), and is output to the outside of the optical element 600a (two-layer structure device) (Y: yellow light).

[0118] A part of the fluorescence emitted from the second color conversion layer 2 and / or a part of the excitation light Bs transmitted through the second color conversion layer 2 passes through the heat insulating layer 3 and excites the first color conversion layer 5. The heat insulating layer must be a transparent medium.

[0119] The excited first color conversion layer 5 emits light. At least a portion of this emitted light passes through the first substrate 11 (heat transport substrate) and is output to the outside of the optical element 600a (two-layer structure device) (R: red light).

[0120] The light output from the optical element 600a is extracted by a lens to the outside of the light source and is incident on an optical system such as an illumination system for use.

[0121] The optical element 600b shown in Figure 6(b) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-6b, with the thermal insulation layer 3-6b being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0122] The heat insulating layer 3-6b is preferably light transmissive in order to excite the first color conversion layer 5. The heat insulating layer 3-6b is, for example, an air layer, and the height of the heat insulating layer 3-6b (also called a gap; the length in the vertical direction in FIG. 6(b)) may be arbitrary, for example, 1 to 500 μm, and about 10 μm may be appropriate. By having the heat insulating layer 3-6b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by disposing the heat insulating layer 3-6b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, and to separate the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0123] The optical element 600b shown in FIG. 6(b) further includes a first substrate 12-6b. The first substrate 12-6b is a heat transport substrate, and has optical transparency. For example, the first substrate 12-6b is made of a sapphire substrate coated with an anti-reflection film (AR film) on both sides. The first substrate 12-6b has a recess K6b-2. The thickness of the first substrate 12-6b in the region where the recess K6b-2 is formed is thinner than the thickness of the first substrate 12-6b in the region where the recess K6b-2 is not formed. Therefore, the light emitted from the first color conversion layer 5 containing red quantum dots (red light (R light)) and the light emitted from the second color conversion layer containing a YAG phosphor (yellow light (Y light)) can be transmitted through the recess K6b-2, thereby improving the light utilization efficiency.

[0124] 6(b), the heat insulating layer 3-6b and the first substrate 12-6b are disposed opposite to each other with the first color conversion layer 5 interposed therebetween. The first substrate 12-6b has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 12-6 and released to the outside of the optical element 600b, thereby suppressing a rise in temperature of the first color conversion layer 5.

[0125] The optical element 600b shown in FIG. 6(b) further includes a second substrate 1-6b. The second substrate 1-6b is a heat transport substrate, has light transmission properties, and is, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1-6b. The first substrate 1-6b has a recess K6b-1. The thickness of the second substrate 1-6b in the region where the recess K6b-1 is formed is thinner than the thickness of the first substrate 1-6b in the region where the recess K6b-1 is not formed, so that the excitation light (blue light (Bs light)) is transmitted through the recess K6b-1, thereby improving the light utilization efficiency.

[0126] 6(b), the heat insulating layer 3-6b and the second substrate 1-6b are disposed opposite to each other via the second color conversion layer 2. The second substrate 1-6b has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1-6b and released to the outside of the optical element 600b, thereby suppressing a rise in temperature of the second color conversion layer 2.

[0127] As shown in Fig. 6(b), the first color conversion layer 5 and the second color conversion layer 2 are bonded via a bonding layer 4. The bonding layer 4 is formed in substantially the same layer as the heat insulating layer 3-6b. The bonding layer 4 may or may not have heat insulating properties, but it is preferable that the bonding layer 4 has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other.

[0128] The optical element 700a shown in Figure 7(a) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-7a, with the thermal insulation layer 3-7a being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0129] The heat insulating layer 3-7a is preferably light transmissive in order to excite the first color conversion layer 5. The heat insulating layer 3-7a is, for example, an air layer, and the height of the heat insulating layer 3-7a (also called a gap; the length in the vertical direction in FIG. 7(a)) may be arbitrary, for example, 1 to 500 μm, and about 10 μm may be appropriate. By having the heat insulating layer 3-7a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by disposing the heat insulating layer 3-7a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, and to separate the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0130] The optical element 700a shown in FIG. 7(a) further includes a first substrate 13. The first substrate 13 is a heat transport substrate and has optical transparency. For example, the first substrate 13 is made of a sapphire substrate coated with an anti-reflection film (AR film) on both sides. As shown in FIG. 7(a), the heat insulating layer 3-7a and the first color conversion layer 5 are arranged opposite each other via the first substrate 13. That is, the heat insulating layer 3-6a, the first substrate 13, and the first color conversion layer 5 are formed in this order from the incident side of the excitation light (the upper side of FIG. 7(a)). The first substrate 13 has thermal conductivity, and the heat generated in the first color conversion layer 5 at the same time as light emission is propagated through the first substrate 13 and released to the outside of the optical element 700a, thereby suppressing the temperature rise of the first color conversion layer 5. The first substrate 13 is arranged between the heat insulating layer 3-7a and the first color conversion layer 5, thereby enabling efficient heat diffusion.

[0131] The optical element 700a shown in FIG. 7(a) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 7(a), the heat insulating layer 3-7a and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 700a, thereby suppressing a temperature rise in the second color conversion layer 2.

[0132] As shown in Fig. 7(a), the first substrate 13 and the second color conversion layer 2 are bonded via a bonding layer 4. The bonding layer 4 is formed in substantially the same layer as the heat insulating layer 3-7a. The bonding layer 4 may or may not have heat insulating properties, but it is preferable that the bonding layer 4 has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other.

[0133] The optical element 700b shown in Figure 7(b) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-7b, with the thermal insulation layer 3-7b being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0134] The heat insulating layer 3-7b is preferably light transmissive in order to excite the first color conversion layer 5. The heat insulating layer 3-7b is, for example, an air layer, and the height of the heat insulating layer 3-7b (also called a gap; the length in the vertical direction in FIG. 7(b)) may be arbitrary, for example, 1 to 500 μm, and may be about 10 μm. By having the heat insulating layer 3-7b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by disposing the heat insulating layer 3-7b, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, thereby separating the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0135] The optical element 700b shown in FIG. 7(b) further includes a first substrate 14. The first substrate 14 is a heat transport substrate and has optical transparency. For example, the first substrate 14 is made of a sapphire substrate coated with an anti-reflection film (AR film) on both sides. As shown in FIG. 7(b), the heat insulating layer 3-7b and the first color conversion layer 5 are arranged opposite each other via the first substrate 14. That is, the heat insulating layer 3-7a, the first substrate 14, and the first color conversion layer 5 are formed in this order from the incident side of the excitation light (the upper side in FIG. 7(b)). The first substrate 14 has thermal conductivity, and the heat generated in the first color conversion layer 5 at the same time as light emission is propagated through the first substrate 14 and released to the outside of the optical element 700b, thereby suppressing the temperature rise of the first color conversion layer 5. The first substrate 13 is arranged between the heat insulating layer 3-7b and the first color conversion layer 5, thereby enabling efficient heat diffusion.

[0136] A lens 15 made of, for example, glass is bonded to the area opposite to the area where the heat insulating layer 3-7b is disposed of the first color conversion layer 5. By bonding the lens 15, the amount of emitted light (Y light and R light) extracted increases, and the light utilization efficiency increases.

[0137] The optical element 700b shown in FIG. 7(b) further includes a second substrate 1-7b. The second substrate 1-6b is a heat transport substrate, has light transmission properties, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1-7b. The first substrate 1-7b has a recess K7b. The thickness of the second substrate 1-7b in the region where the recess K7b is formed is thinner than the thickness of the first substrate 1-7b in the region where the recess K7b-1 is not formed, so that the excitation light (blue light (Bs light)) can be transmitted to the recess K6b-1, thereby improving the light utilization efficiency.

[0138] 7(b), the heat insulating layer 3-7b and the second substrate 1-7b are disposed opposite each other via the second color conversion layer 2. The second substrate 1-7b has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1-7b and released to the outside of the optical element 700b, thereby suppressing a rise in temperature of the second color conversion layer 2.

[0139] As shown in Fig. 7(b), the first substrate 14 and the second color conversion layer 2 are bonded via a bonding layer 4. The bonding layer 4 is formed in substantially the same layer as the heat insulating layer 3-7b. The bonding layer 4 may or may not have heat insulating properties, but it is preferable that the bonding layer 4 has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other.

[0140] According to the fifth embodiment (optical element example 5) of the present technology, the thermal insulation between the two layers (between the first color conversion layer 5 and the second color conversion layer 2) can suppress the temperature rise between the first color conversion layer 5 and the second color conversion layer 2, and in particular, it is possible to suppress temperature quenching of the light emission of the first color conversion layer 5, achieve high light emission efficiency, realize the miniaturization of the light source by improving the light emission efficiency, and suppress quantum dot (QD) degradation during manufacturing.

[0141] The contents described above regarding the optical element of the fifth embodiment (optical element example 5) of the present technology can be applied to the optical elements of the first to fourth embodiments of the present technology described above and the optical element of the sixth embodiment of the present technology described below, unless there is any particular technical contradiction.

[0142] 7. Sixth embodiment (sixth example of optical element) An optical element according to a sixth embodiment (example 6 of optical element) of the present technology will be described with reference to Fig. 8. Fig. 8 is a diagram showing a configuration example of an optical element according to the sixth embodiment of the present technology, and more specifically, Fig. 8(a) is a cross-sectional view of an optical element 800a of the sixth embodiment, Fig. 8(b) is a top view of a rotating wheel part 800b having an optical element 800c of the sixth embodiment, and Fig. 8(c) is a cross-sectional view of the optical element 800c when cutting from the front side of the paper surface of the P8 region shown in Fig. 8(b) toward the back side of the paper surface.

[0143] The optical element 800a shown in Figure 8(a) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-8a, with the thermal insulation layer 3-8a being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0144] The heat insulating layer 3-8a is preferably light-transmitting so as to excite the first color conversion layer 5. The heat insulating layer 3-8a is, for example, an air layer, and the height of the heat insulating layer 3-8a (also called a gap; the length in the vertical direction in FIG. 8(a)) may be arbitrary, for example, 1 to 500 μm, and about 10 μm may be appropriate. By having the heat insulating layer 3-8a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by disposing the heat insulating layer 3-8a, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, and to separate the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0145] The optical element 800a shown in FIG. 8(a) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 8(a), the heat insulating layer 3-8a and the first substrate 6 are disposed opposite each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 800a, thereby suppressing a rise in temperature of the first color conversion layer 5.

[0146] The first substrate 6 can be connected to a rotating wheel unit, for example, to rotate the first color conversion layer 5 in the direction from the front side of the paper to the back side of the paper to the front side of the paper. The first color conversion layer includes, for example, red quantum dots, and the luminous efficiency of the red quantum dots is highly temperature dependent. Therefore, by rotating the first color conversion layer 5, the air is refreshed and the first color conversion layer 5 can be efficiently cooled. This can improve the luminous efficiency of the red quantum dots.

[0147] The optical element 800a shown in FIG. 8(a) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 8(a), the heat insulating layer 3-8a and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 800a, thereby suppressing the temperature rise of the second color conversion layer 2.

[0148] In optical element 800a, first color conversion layer 5 and first substrate 6, and second color conversion layer 2 and second substrate 1 are each fixed by a fixing member separately.

[0149] The optical element 800c shown in Figure 8(c) comprises a first color conversion layer 5, a second color conversion layer 2, and a thermal insulation layer 3-8c, with the thermal insulation layer 3-8c being disposed between the first color conversion layer 5 and the second color conversion layer 2.

[0150] The heat insulating layer 3-8c is preferably light-transmitting so as to excite the first color conversion layer 5. The heat insulating layer 3-8c is, for example, an air layer, and the height of the heat insulating layer 3-8a (also called a gap; the length in the vertical direction in FIG. 8(c)) may be arbitrary, for example, 1 to 500 μm, and about 10 μm may be appropriate. By having the heat insulating layer 3-8c, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 to each other. That is, by disposing the heat insulating layer 3-8c, it is possible to suppress the transfer of the heat generated in the first color conversion layer 5 to the second color conversion layer 2, and to suppress the transfer of the heat generated in the second color conversion layer 2 to the first color conversion layer 5, and to separate the heat exhaust path of the first color conversion layer 5 from the heat exhaust path of the second color conversion layer 2.

[0151] The optical element 800c shown in FIG. 8(c) further includes a first substrate 6. The first substrate 6 is a base substrate, and has light reflectivity, and is composed of, for example, an aluminum substrate including a light reflecting film. As shown in FIG. 8(c), the heat insulating layer 3-8c and the first substrate 6 are disposed opposite each other via the first color conversion layer 5. The first substrate 6 has thermal conductivity, and heat generated in the first color conversion layer 5 simultaneously with light emission is propagated through the first substrate 6 and released to the outside of the optical element 800a, thereby suppressing a temperature rise in the first color conversion layer 5.

[0152] The optical element 800c shown in FIG. 8(a) further includes a second substrate 1. The second substrate 1 is a heat transport substrate and has optical transparency, and is composed of, for example, a sapphire substrate coated with an anti-reflection film (AR film) on both sides of the second substrate 1. As shown in FIG. 8(c), the heat insulating layer 3-8c and the second substrate 1 are disposed opposite each other via the second color conversion layer 2. The second substrate 1 has thermal conductivity, and heat generated in the second color conversion layer 2 simultaneously with light emission is propagated through the second substrate 1 and released to the outside of the optical element 800c, thereby suppressing the temperature rise of the second color conversion layer 2.

[0153] As shown in FIG. 8(c), the first color conversion layer 5 and the second color conversion layer 2 are bonded via a bonding layer 4-8. As shown in FIG. 8(b), the bonding layer 4-8 is pattern bonded. The bonding layer 4-8 is formed in substantially the same layer (substantially the same layer) as the heat insulating layer 3-8c. The bonding layer 4-8 may or may not have heat insulating properties, but it is preferable that the bonding layer 4-8 has heat insulating properties so that the heat generated in the first color conversion layer 5 and the heat generated in the second color conversion layer 2 do not move to each other.

[0154] As shown in FIG. 8(b), the optical element 800c is connected to the rotating wheel unit 801b, and the optical element 800c rotates. The rotating internal fins of the rotating wheel unit 801b allow air to continuously flow outward as shown by the arrow T81c in FIG. 8(c), improving the refreshing of the air. This improves the cooling performance and improves the luminous efficiency of the first color conversion layer 5 and the second color conversion layer 2. In particular, when the first color conversion layer includes red quantum dots, the luminous efficiency of the red quantum dots is highly temperature-dependent, so that by rotating the optical element 800c, the air is refreshed and the first color conversion layer 5 can be efficiently cooled. This improves the luminous efficiency of the red quantum dots (red luminous efficiency).

[0155] According to the sixth embodiment (optical element example 6) of the present technology, the thermal insulation between the two layers (between the first color conversion layer 5 and the second color conversion layer 2) can suppress the temperature rise between the first color conversion layer 5 and the second color conversion layer 2, and in particular, it is possible to suppress temperature quenching of the light emission of the first color conversion layer 5, achieve high light emission efficiency, realize the miniaturization of the light source by improving the light emission efficiency, and suppress quantum dot (QD) degradation during manufacturing.

[0156] The above description of the optical element of the sixth embodiment (example 6 of optical element) of the present technology can be applied to the optical elements of the first to fifth embodiments of the present technology described above, unless there is any particular technical contradiction.

[0157] 8. Seventh embodiment (example 1 of light source device) A light source device of a seventh embodiment (an example of a light source device) of the present technology is a light source device including an optical element of at least one embodiment of the optical elements of the first to fourth embodiments and the sixth embodiment of the present technology, a light source that emits excitation light, and a moving mechanism that moves the irradiation position of the excitation light on the optical element over time.

[0158] A light source device according to a seventh embodiment (example 1 of light source device) of the present technology will be described with reference to Fig. 9. Fig. 9 is a diagram showing a configuration example of a light source device according to the seventh embodiment of the present technology, and more specifically, Fig. 9 is a diagram showing a configuration example of a light source device (reflective light source device) 9000 of the seventh embodiment.

[0159] The light source device 9000 includes an excitation light source 11M, a polarizing beam splitter 12M, a quarter-wave plate 13M, a light-collecting optical system 14M (optical system), an optical element 900, and a moving mechanism (drive unit) (not shown in FIG. 9).

[0160] In the light source device 9000, a focusing optical system 14M, a quarter wave plate 13M, and a polarizing beam splitter 12M are arranged in this order on the optical path of the light emitted from the optical element 900. In addition, an excitation light source 11M is arranged in a direction substantially perpendicular to the optical path of the light emitted from the optical element 900.

[0161] As the excitation light source 11M, for example, a blue laser that emits blue light (excitation light Bs) with a wavelength of 445 nm is used. Furthermore, the excitation light source 11M emits linearly polarized (S-polarized) excitation light Bs.

[0162] In addition, when the excitation light source 11M is configured with a blue laser, it may be configured to obtain a predetermined output of excitation light Bs from one blue laser, or it may be configured to obtain a predetermined output of excitation light Bs by combining the emitted light from multiple blue lasers. Furthermore, the wavelength of the blue light (excitation light Bs) is not limited to 445 nm, and any wavelength within the wavelength band of light called blue light can be used.

[0163] The polarizing beam splitter 12M separates the excitation light Bs incident from the excitation light source 11M and the outgoing light (combined light) incident from the optical element 900. Specifically, the polarizing beam splitter 12M reflects the excitation light Bs (S-polarized light) incident from the excitation light source 11M, and emits the reflected light to the optical element 900 via the focusing optical system 14M. The polarizing beam splitter 12M also transmits the light emitted from the optical element 900, and emits the transmitted light outside the light source device 9000 (for example, an image projection device, etc.).

[0164] The spectral characteristics of the polarizing beam splitter 12M are designed so that the polarizing beam splitter 12M can perform the above-mentioned light separation operation. The configuration of the optical system that separates the excitation light Bs incident from the excitation light source 11M and the output light from the optical element 900 is not limited to the polarizing beam splitter 12M, and any optical system can be used as long as it has a configuration that enables the above-mentioned light separation operation.

[0165] The quarter-wave plate 13M is a phase element that generates a phase difference of π / 2 for the incident light, and converts the linearly polarized light into circularly polarized light when the incident light is linearly polarized, and converts the circularly polarized light into linearly polarized light when the incident light is circularly polarized. The quarter-wave plate 13M converts the linearly polarized excitation light output from the polarizing beam splitter 12M into circularly polarized excitation light, and converts the circularly polarized excitation light component included in the combined light output from the optical element 900 into linearly polarized light.

[0166] The focusing optical system 14M focuses the excitation light emitted from the quarter-wave plate 13M to a predetermined spot diameter, and emits the focused excitation light (hereinafter referred to as focused light) to the optical element 900. The focusing optical system 14M also converts the combined light emitted from the optical element 900 into parallel light, and emits the parallel light to the quarter-wave plate 13M. The focusing optical system 14M may be configured, for example, with a single collimating lens, or may be configured to convert the incident light into parallel light using multiple lenses.

[0167] The optical element 900 includes, in order from the incident side of the excitation light Bs, a second substrate 100 (e.g., a heat transport substrate having optical transparency) including a dichroic film, a second color conversion layer 200, a heat insulating layer 300-9, a first color conversion layer 500, and a first substrate 600 (e.g., a base substrate having optical reflectivity). The first color conversion layer 500 and the second color conversion layer 200 are bonded together via a bonding layer 400. The bonding layer 400 is formed in substantially the same layer (substantially the same layer) as the heat insulating layer 300-9.

[0168] The optical element 900 absorbs a part of the excitation light (blue light) incident via the light collecting optical system 14M, emits light in a predetermined wavelength band, and reflects the remaining excitation light. That is, the first color conversion layer 500 absorbs a part of the excitation light (blue light) and emits red light (for example, light in a wavelength band of 590 to 680 nm), and the second color conversion layer 200 absorbs a part of the excitation light (blue light) and emits yellow light (for example, light in a wavelength band of 480 to 680 nm), and reflects the remaining excitation light (blue light) by a dichroic film included in the second substrate (heat transport substrate). Note that a part of the remaining excitation light (blue light) may be reflected by the first substrate 600 (base substrate). The optical element 900 then combines the emitted light composed of red light and yellow light with a portion of the excitation light (blue light) reflected by the dichroic film (and the first substrate 600 (base substrate)), and emits the combined light to the focusing optical system 14.

[0169] The light (arrow P9) emitted outside the light source device 9000 (for example, an image projection device or the like) is white light (W). In the optical element 900, the first color conversion layer 500 emits red light (for example, light in a wavelength band of 590 to 680 nm) and the second color conversion layer 200 emits yellow light (for example, light in a wavelength band of 480 to 680 nm) due to the excitation light Bs (S-polarized light). Then, these red light (R) and yellow light (Y) pass through the polarizing beam splitter 12M regardless of their polarization direction, and a portion (P-polarized light and unpolarized light) of the excitation light (blue light (B)) reflected by the optical element 900 passes through the polarizing beam splitter 12M, and the red light (R), yellow light (Y), and blue light (B) that pass through the polarizing beam splitter 12M are combined to generate white light (W), which is then emitted outside the light source device 9000 (for example, to an image projection device, etc.) (arrow P9).

[0170] 9. Eighth embodiment (example 2 of light source device) A light source device of an eighth embodiment (an example of a light source device) of the present technology is a light source device including an optical element of the fifth embodiment of the present technology, a light source that emits excitation light, and a moving mechanism that moves the irradiation position of the excitation light on the optical element over time.

[0171] A light source device according to an eighth embodiment (example 2 of light source device) of the present technology will be described with reference to Fig. 10. Fig. 10 is a diagram showing a configuration example of a light source device according to an eighth embodiment of the present technology, and more specifically, Fig. 10 is a diagram showing a configuration example of a light source device (transmissive light source device) 10000 of the eighth embodiment.

[0172] The light source device 10000 includes an excitation light source 11M, a light collecting optical system 14 (optical system) M, an optical element 1000, and a moving mechanism (drive unit) (not shown in FIG. 10).

[0173] In the light source device 10000, an excitation light source 11M, a focusing optical system 14M, and an optical element 1000 are arranged in this order.

[0174] As the excitation light source 11M, for example, a blue laser that emits blue light (excitation light Bs) with a wavelength of 445 nm is used.

[0175] In addition, when the excitation light source 11M is configured with a blue laser, it may be configured to obtain a predetermined output of excitation light Bs from one blue laser, or it may be configured to obtain a predetermined output of excitation light Bs by combining the emitted light from multiple blue lasers. Furthermore, the wavelength of the blue light (excitation light Bs) is not limited to 445 nm, and any wavelength within the wavelength band of light called blue light can be used.

[0176] The focusing optical system 14M focuses the excitation light emitted from the excitation light source 11M to a predetermined spot diameter, and emits the focused excitation light (hereinafter referred to as focused light) to the optical element 1000. The focusing optical system 14M may be configured, for example, with a single collimating lens, or may be configured to convert the incident light into parallel light using multiple lenses.

[0177] The optical element 1000 includes, in order from the incident side of the excitation light Bs, a second substrate (e.g., a heat transport substrate having optical transparency) 100 including a dichroic film, a second color conversion layer 200, a heat insulating layer 300-10, a first color conversion layer 500, and a first substrate (e.g., a heat transport substrate having optical transparency) 100-1. The first color conversion layer 500 and the second color conversion layer 200 are bonded via a bonding layer 400. The bonding layer 400 is formed in substantially the same layer (substantially the same layer) as the heat insulating layer 300-10.

[0178] The optical element 1000 passes through the second substrate 100, which includes a dichroic film that transmits the excitation light (blue light) incident through the focusing optical system 14M, absorbs a portion of the excitation light (blue light), emits light in a predetermined wavelength band, and emits it outside the light source device 10000 (e.g., an image projection device, etc.), while transmitting the remaining excitation light (blue light) through the first substrate 100-1 and emitting it outside the light source device 10000 (e.g., an image projection device, etc.). That is, the first color conversion layer 500 absorbs a part of the excitation light (blue light) and emits red light (for example, light in a wavelength band of 590 to 680 nm), the second color conversion layer 200 absorbs a part of the excitation light (blue light) and emits yellow light (for example, light in a wavelength band of 480 to 680 nm), and the emitted light consisting of the red light and the yellow light passes through the first substrate (heat transport substrate), and further, a part of the emitted light is reflected by a dichroic film included in the second substrate and then passes through the first substrate, and the remaining excitation light (blue light) passes through the first substrate (heat transport substrate). Then, the optical element 1000 combines the emitted light consisting of the red light and the yellow light with a part of the excitation light (blue light), and emits the combined light outside the light source device 10000 (for example, an image projection device, etc.).

[0179] The light (arrow P10) emitted outside the light source device 10000 (for example, an image projection device or the like) is, for example, white light (W), and the optical element 1000 emits red light (for example, light in a wavelength band of 590 to 680 nm) from the first color conversion layer 500 and yellow light (for example, light in a wavelength band of 480 to 680 nm) from the second color conversion layer 200 due to the excitation light Bs. Then, the red light (R) and yellow light (Y) are combined with a portion of the excitation light (blue light (B)) that has passed through the optical element 1000 to generate white light (W).

[0180] <10. Ninth embodiment (example of projector)> A projector according to a ninth embodiment (an example of a projector) of the present technology is a projector including a light source device (a reflective light source device) according to a seventh embodiment of the present technology or a light source device (a transmissive light source device) according to an eighth embodiment of the present technology, and an image projection device that generates a predetermined image light using light emitted from the light source device and projects the generated image light to the outside.

[0181] A projector according to a ninth embodiment (example of a projector) of the present technology will be described with reference to Fig. 11. Fig. 11 is a diagram showing a configuration example of a projector according to the ninth embodiment of the present technology, and more specifically, Fig. 11 is a diagram showing a configuration example of a projector 10M according to the ninth embodiment.

[0182] The projector 10M includes a light source device (reflective light source device) 9000M and an image projection device 2M.

[0183] The light source device 9000M includes an excitation light source 11M, a polarizing beam splitter 12M, a quarter-wave plate 13M, a focusing optical system 14M (optical system), an optical element 100, and a moving mechanism (drive unit) 16M. Note that the optical element 100 (the optical element of the first embodiment), the excitation light source 11M, the polarizing beam splitter 12M, the quarter-wave plate 13M, and the focusing optical system 14M (optical system) are as described above, and therefore detailed description thereof will be omitted here.

[0184] 11, the moving mechanism (drive unit) 16M is a motor, which rotates the optical element 100 at a predetermined number of rotations. At this time, the drive unit 16M drives the optical element 100 so that the optical element 100 rotates within a plane (excitation light irradiation surface of the optical element 100) perpendicular to the irradiation direction of the excitation light. As a result, the irradiation position of the excitation light within the optical element 100 changes (moves) over time at a speed corresponding to the number of rotations within the plane perpendicular to the irradiation direction of the excitation light.

[0185] As described above, by rotating the optical element 100 with the driving unit 16M and changing the irradiation position of the excitation light in the optical element 15 over time, it is possible to suppress the temperature rise at the irradiation position and prevent the reduction in the luminous efficiency of the first color conversion layer 5 and the second color conversion layer 2. In addition, it takes some time (for example, about several nsec) for the phosphor atoms and / or quantum dots to absorb the excitation light and emit light, and even if the next excitation light is irradiated to the phosphor atoms during that excitation period, they will not emit light in response to that excitation light. However, by changing the irradiation position of the excitation light in the optical element 100 over time, non-excited phosphor atoms and / or quantum dots are successively arranged at the irradiation position of the excitation light, and the first color conversion layer 5 and the second color conversion layer 2 can emit light more efficiently.

[0186] Although an example is shown in which the optical element 100 is rotationally driven by the driving unit 16M, the present embodiment is not limited thereto, and any configuration may be used as long as the irradiation position of the excitation light in the optical element 100 changes over time. For example, the irradiation position of the excitation light may be changed over time by linearly reciprocating the optical element 100 in a predetermined direction in a plane perpendicular to the irradiation direction of the excitation light. Alternatively, the irradiation position of the excitation light may be changed over time by fixing the optical element 100 and moving the excitation light source 11M and various optical systems relative to the optical element 100.

[0187] 11, a disk-shaped substrate 30M is attached to the first substrate (base substrate) 6 of the optical element 100, and a rotating shaft 16aM connected to a driving unit 16M passes through the center of the substrate 30M and is connected to a fixed hub 16bM. As a result, the optical element 100 is rotationally driven by the driving unit 16M.

[0188] The image projection device 2M optically processes light (white light LW in this example) emitted from the light source device 9000M to generate image light LI, and enlarges and projects the image light LI onto an external screen, for example. The image projection device 2M has, for example, a spectroscopic optical system 20M, three LCD light modulation elements (hereinafter, referred to as a first LCD panel 21M to a third LCD panel 23M, respectively), a prism 24M, and a projection optical system 25M. Note that the configuration of the image projection device 2M is not limited to the example shown in FIG. 1, and can be appropriately changed depending on, for example, the application. For example, various optical elements required may be appropriately arranged on the optical path between each component in the image projection device 2M.

[0189] In the image projection device 2M of this example, the first LCD panel 21M and the third LCD panel 23M are arranged so that their light exit surfaces face each other, and the second LCD panel 22M is arranged in a direction perpendicular to the facing direction of the first LCD panel 21M to the third LCD panel 23M. A prism 24M is arranged in an area surrounded by the light exit surfaces of the first LCD panel 21M to the third LCD panel 23M. In this example, a projection optical system 25M is arranged at a position facing the light exit surface of the second LCD panel 22M, sandwiching the prism 24M. The spectroscopic optical system 20M is provided on the light entrance side of the first LCD panel 21M to the third LCD panel 23M.

[0190] The spectroscopic optical system 20M is composed of, for example, a dichroic mirror, a reflecting mirror, etc., and separates the white light LW incident from the light source device 9000M into blue light LB, green light LG, and red light LR, and emits the light of each wavelength component to the corresponding LCD panel. In this example, the spectroscopic optical system 20M emits the separated blue light LB, green light LG, and red light LR to the first LCD panel 21M, the second LCD panel 22M, and the third LCD panel 23M, respectively. In this embodiment, the polarization direction of each wavelength component is also adjusted to a predetermined direction in the spectroscopic optical system 20M.

[0191] Each of the first LCD panel 21M to the third LCD panel 23M is composed of a transmissive LCD panel. Each LCD panel transmits or blocks (modulates) incident light on a liquid crystal cell basis by changing the arrangement of liquid crystal molecules sealed in the liquid crystal cell (not shown) based on a drive signal from a panel drive unit (not shown). Then, each LCD panel emits modulated light of a predetermined wavelength (modulated light) to the prism 24M.

[0192] The prism 24M combines the modulated light of each wavelength component incident from the first LCD panel 21M to the third LCD panel 23M, respectively, and emits the combined light, that is, image light LI, to the projection optical system 25M.

[0193] The projection optical system 25M enlarges and projects the image light incident from the prism 24M onto a display surface such as an external screen.

[0194] Note that the embodiments according to the present technology are not limited to the above-described embodiments, and various modifications are possible without departing from the gist of the present technology.

[0195] Furthermore, the effects described in this specification are merely examples and are not limiting, and other effects may also be obtained.

[0196] The present technology can also be configured as follows. [1] A first color conversion layer, a second color conversion layer, and a heat insulating layer, The heat insulating layer is disposed between the first color conversion layer and the second color conversion layer. [2] The optical element according to [1], wherein the heat insulating layer has optical transparency. [3] The optical element according to [1] or [2], wherein the heat insulating layer contains a material having optical transparency. [4] At least one of the first color conversion layer and the second color conversion layer has an uneven portion, The optical element according to any one of [1] to [3], wherein the heat insulating layer is formed by bonding the first color conversion layer and the second color conversion layer via the convex portion. [5] At least one of the first color conversion layer and the second color conversion layer has a recess; The optical element according to any one of [1] to [4], wherein the heat insulating layer is formed by bonding the first color conversion layer and the second color conversion layer via the recess. [6] The optical element according to any one of [1] to [5], wherein the first color conversion layer and the second color conversion layer are bonded via a bonding layer. [7] The optical element according to [6], wherein the bonding layer has heat insulation properties. [8] The optical element according to [6] or [7], wherein the bonding layer contains beads. [9] Further comprising a first substrate, the first substrate is thermally conductive; The optical element according to any one of [1] to [8], wherein the heat insulating layer and the first substrate are disposed opposite each other with the first color conversion layer interposed therebetween.

[10] The optical element according to [9], wherein the first substrate has optical reflectivity.

[11] The optical element according to [9] or

[10] , wherein the first substrate is optically transparent.

[12] The optical element according to any one of [9] to

[11] , wherein the first substrate includes a region having optical transparency and a region having optical reflectivity.

[13] the second color conversion layer and the first substrate are bonded via a first bonding member, The optical element according to any one of [9] to

[12] , wherein the first bonding member has thermal conductivity.

[14] the first bonding member and the first substrate are bonded via a second bonding member, The optical element according to

[13] , wherein the second bonding member has heat insulation properties.

[15] the first substrate has a recess on the heat insulating layer side, The optical element according to any one of [9] to

[14] , wherein the first color conversion layer is embedded in the recess.

[16] Further comprising a second substrate, the second substrate is thermally conductive; The optical element according to any one of [1] to

[15] , wherein the heat insulating layer and the second substrate are disposed opposite each other with the second color conversion layer interposed therebetween.

[17] The optical element according to

[16] , wherein the second substrate is optically transparent.

[18] The optical element according to

[16] or

[17] , wherein the second substrate includes a region having optical transparency and a region having optical reflectivity.

[19]

[18] An optical element according to any one of [1] to

[18] ; A light source that emits excitation light; a moving mechanism that moves the irradiation position of the excitation light on the optical element over time.

[20]

[19] A light source device according to the present invention; a projection device that generates a predetermined image light by using the light emitted from the light source device and projects the generated image light to the outside; [Explanation of symbols]

[0197] 1, 1-5...Second substrate (heat transport substrate), 2...second color conversion layer, 3…insulation layer, 4...bonding layer, 5...first color conversion layer, 6...First substrate (base substrate), 11, 12-6b, 13, 14...first substrate (heat transport substrate), 100, 200a, 200b, 300a, 300b, 400a, 400b, 500a, 500b, 500c, 600a, 600b, 700a, 700b, 800a, 800b, 900, 1000...optical elements, 9000, 9000M, 10000...Optical equipment, 10M...Projector.

Claims

1. A first color conversion layer, a second color conversion layer, and a heat insulating layer, the heat insulating layer is disposed between the first color conversion layer and the second color conversion layer; Further comprising a first substrate, the first substrate is thermally conductive; the heat insulating layer and the first substrate are disposed opposite to each other via the first color conversion layer; An optical element, wherein the first substrate includes a region having optical transparency and a region having optical reflectivity.

2. The optical element according to claim 1 , wherein the heat insulating layer is optically transparent.

3. The optical element according to claim 1 , wherein the heat insulating layer comprises a material having optical transparency.

4. At least one of the first color conversion layer and the second color conversion layer has a convex portion, The optical element according to claim 1 , wherein the first color conversion layer and the second color conversion layer are bonded together via the convex portion to form the heat insulating layer.

5. At least one of the first color conversion layer and the second color conversion layer has a recess, The optical element described in claim 1, wherein the first color conversion layer and the second color conversion layer are bonded through an area where the recess is not formed, and the insulating layer is formed between the first color conversion layer and the second color conversion layer in the area where the recess is formed.

6. The optical element according to claim 1 , wherein the first color conversion layer and the second color conversion layer are bonded via a bonding layer.

7. The optical element according to claim 6 , wherein the bonding layer has a heat insulating property.

8. The optical element of claim 6 , wherein the bonding layer comprises beads.

9. The optical element according to claim 1 , wherein the first substrate is optically reflective.

10. The optical element according to claim 1 , wherein the first substrate is optically transparent.

11. the second color conversion layer and the first substrate are bonded via a first bonding member; The optical element according to claim 1 , wherein the first bonding member has thermal conductivity.

12. the first bonding member and the first substrate are bonded via a second bonding member, The optical element according to claim 11 , wherein the second bonding member has a heat insulating property.

13. the first substrate has a recess on the heat insulating layer side, The optical element according to claim 1 , wherein the first color conversion layer is embedded in the recess.

14. Further comprising a second substrate, the second substrate is thermally conductive; The optical element according to claim 1 , wherein the heat insulating layer and the second substrate are disposed opposite each other with the second color conversion layer interposed therebetween.

15. The optical element according to claim 14 , wherein the second substrate is optically transparent.

16. The optical element according to claim 14 , wherein the second substrate includes an area having optical transparency and an area having optical reflectivity.

17. The optical element according to claim 1 ; A light source that emits excitation light; a moving mechanism that moves the irradiation position of the excitation light on the optical element over time.

18. The light source device according to claim 17 ; a projection device that generates a predetermined image light by using the light emitted from the light source device and projects the generated image light to the outside;

Images