Light source device and image projection device

Abstract

To provide a light guide optical device that can compose rays of light from three or more light sources with high efficiency, a light source device, and an image projection device.SOLUTION: A light guide optical device comprises a light path composition unit 100 that composes rays of light incident from three directions different from each other and emits composite light in an emission direction. The light path composition unit 100 has a first deflection unit 101 that deflects, in the emission direction, first light incident from a first direction, a second deflection unit 102 that deflects, in the emission direction, second light incident from a second direction different from the first direction, and a transmission unit 105 that transmits, in the emission direction, third light incident from a third direction different from the first direction and the second direction. The transmission unit 105 is located between the first deflection unit 101 and the second deflection unit 102.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention ,light The present invention relates to an image source device, and an image projection device. [Background technology]

[0002] Projectors (one example of an image projection device) are still mostly full HD even for large models, but 4K is expected to become more widespread in the future. Also, 8K projectors are already being considered as a technical option for the future, and there will be a demand for even larger projector screens and associated higher brightness lighting systems.

[0003] In this situation, in order to further increase the brightness of the projector, a technology is known that combines blue laser light with fluorescent light emitted from a phosphor that uses the laser light as excitation light. Patent Document 2 discloses a light source optical system that uses a laser light source and a phosphor. Patent Document 1 discloses an optical device that is thin and compact by combining light beams from multiple light-emitting elements. Summary of the Invention [Problem to be solved by the invention]

[0004] However, in a technique for combining a plurality of light beams (light paths), when combining light beams from three or more light sources, it is difficult to combine the light beams emitted from the respective light sources with high efficiency.

[0005] The present invention has been made in view of the above, and provides a method for synthesizing light from three or more light sources with high efficiency. Light The present invention aims to provide an image source device and an image projection device. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the object, the present invention provides a light guide optical device including a light path combining section that combines light incident from three different directions and outputs the combined light in an emission direction. and , The illumination device includes a first light source that emits a first light, a second light source that emits a second light, and a third light source that emits a third light,The optical path combining unit receives light from a first direction. The above A first deflection unit that deflects a first light in an exit direction and a second deflection unit that deflects a first light from a second direction different from the first direction. The above a second deflection unit that deflects the second light in the emission direction; and a second deflection unit that deflects the second light from a third direction different from the first direction and the second direction. The above a transmission section that transmits the third light in the emission direction, the transmission section being located between the first deflection section and the second deflection section. The light guiding optical device forms conjugate images of the first light source, the second light source, and the third light source in the optical path combining section, the conjugate images of the first light source, the second light source, and the third light source are arranged in a line when viewed from the emission direction, and the conjugate image of the third light source is smaller than the conjugate image of the first light source and the conjugate image of the second light source. . Effect of the Invention

[0007] The present invention has an advantage that it is possible to combine light from three or more light sources with high efficiency. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram for explaining an example of a light-guiding optical device and an optical path combining unit according to the present embodiment. [Diagram 2] FIG. 2 is a diagram for explaining an example of the light-guiding optical device and the optical path combining unit according to the present embodiment. [Diagram 3] FIG. 3 is a diagram for explaining an example of the light guide optical device and the optical path combining unit according to the present embodiment. [Figure 4] FIG. 4 is a diagram showing an example of the intensity distribution of light irradiated onto the entrance of the light tunnel in the light source device according to the present embodiment. [Diagram 5] FIG. 5 is a diagram showing an example of the intensity distribution of light irradiated onto the entrance of the light tunnel in the light source device according to the present embodiment. [Figure 6] FIG. 6 is a diagram for explaining an example of the configuration of the light guiding optical device according to the present embodiment. [Figure 7] FIG. 7 is a diagram for explaining an example of the configuration of the light guiding optical device according to the present embodiment. [Figure 8] FIG. 8 is a diagram for explaining an example of the configuration of the light guiding optical device according to the present embodiment. [Figure 9]FIG. 9 is a diagram for explaining an example of a light source included in the light-guiding optical device according to the present embodiment. [Figure 10] FIG. 10 is a diagram for explaining another example of the light source included in the light-guiding optical device according to the present embodiment. [Figure 11] FIG. 11 is a diagram for explaining another example of the light source included in the light-guiding optical device according to the present embodiment. [Figure 12] FIG. 12 is a diagram for explaining another example of the light source included in the light-guiding optical device according to the present embodiment. [Figure 13] FIG. 13 is a diagram for explaining another example of the light source included in the light-guiding optical device according to the present embodiment. [Figure 14] FIG. 14 is a diagram showing an example of the configuration of a prism included in the light guide optical device according to the present embodiment. [Figure 15] FIG. 15 is a diagram showing an example of the configuration of a prism included in the light-guiding optical device according to the present embodiment. [Figure 16] FIG. 16 is a diagram showing an example of the configuration of a light guiding optical device according to this embodiment. [Figure 17] FIG. 17 is a diagram showing an example of the configuration of a light guiding optical device according to this embodiment. [Figure 18] FIG. 18 is a diagram showing another example of a prism included in the light guide optical device according to the present embodiment. [Figure 19] FIG. 19 is a diagram showing another example of a prism included in the light guide optical device according to the present embodiment. [Figure 20] FIG. 20 is a diagram showing another example of the optical path combining section included in the light guide optical device according to the present embodiment. [Figure 21] FIG. 21 is a diagram showing another example of the optical path combining section included in the light guide optical device according to the present embodiment. [Figure 22] FIG. 22 is a diagram showing another example of the optical path combining section included in the light guide optical device according to the present embodiment. [Diagram 23] FIG. 23 is a diagram showing another example of the light guiding optical device according to the present embodiment. [Figure 24] FIG. 24 is a diagram showing an example of the configuration of an image projection device according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a light guiding optical device, a light source device, and an image projection device will be described in detail with reference to the accompanying drawings.

[0010] 1 to 3 are diagrams for explaining an example of a light guiding optical device and a light path combining section according to the present embodiment. As shown in Figs. 1 and 2, the light guiding optical device according to the present embodiment has a light path combining section 100. Also, as shown in Fig. 3, the light source device according to the present embodiment has light sources LS1 to LS3, the light path combining section 100, and a light tunnel LT. In the following description, when it is not necessary to distinguish between the light sources LS1 to LS3, they will be referred to as light source LS.

[0011] Light sources LS1 to LS3 are examples of light sources that emit light. Specifically, light source LS1 is an example of a first light source that emits light (an example of a first light) in the positive direction of the z axis. Light source LS2 is an example of a second light source that emits light (an example of a second light) in the negative direction of the z axis.

[0012] The light source LS3 is an example of a third light source that emits light (an example of a third light) in the positive direction of the x axis. In the present embodiment, it is preferable that the light source LS3 emits light that travels straight toward the positive direction of the x axis (an example of an emission direction).

[0013] This reduces the loss due to the deflection of the light emitted from the light source LS3 in the emission direction. Also, since the effective area through which the light emitted from the light source LS3 passes in the optical path combining unit 100 can be reduced, the light guide optical device can be made compact.

[0014] In the present embodiment, the light source LS3 is preferably a laser light source that emits laser light. This allows the light emitted from the light source LS3 to be sharply focused on the optical path combining unit 100, thereby reducing loss of the light.

[0015] The light path combining unit 100 is an example of a light path combining unit that combines light incident from three different directions and emits the combined light in the positive direction of the x-axis (an example of an emission direction). For example, the light path combining unit 100 has reflecting surfaces 101 and 102 and a transmitting unit 105 as shown in FIG.

[0016] The reflecting surface 101 is an example of a first deflecting unit that reflects (an example of deflection) light incident from the light source LS1 (an example of a first light), in other words, light incident from the negative direction of the z axis, in the positive direction of the x axis (an example of an emission direction). The reflecting surface 102 is an example of a second deflecting unit that reflects (an example of deflection) light incident from the light source LS2 (an example of a second light), in other words, light incident from the positive direction of the z axis, in the positive direction of the x axis.

[0017] The transmitting portion 105 is an example of a transmitting portion that transmits light incident from the negative direction of the x-axis to the positive direction of the x-axis. The transmitting portion 105 is located between the reflecting surface 101 and the reflecting surface 102. In other words, the light collecting portions of the light incident from each of the light sources LS1 to LS3 and collected on the reflecting surface 101, the reflecting surface 102, and the transmitting portion 105 do not overlap with each other. This makes it possible to reduce loss caused by the light being vignetted by the reflecting surface 101 and the reflecting surface 102 to be collected on the transmitting portion 105 (light from the light source LS3 being blocked by the reflecting surface 101 and the reflecting surface 102). As a result, it becomes possible to combine the light from three or more light sources LS with high efficiency.

[0018] In this embodiment, the light guide optical device focuses the light emitted from the light sources LS1 to LS3 on the light path synthesis section 100, thereby forming conjugate images of the light sources LS1 to LS3 on the light path synthesis section 100. This makes it possible to reduce the effective area, which is an area in which the light is deflected in the light path synthesis section 100, and to miniaturize the light source device.

[0019] In this case, it is preferable that the conjugate images of the light sources LS1 to LS3 formed in the optical path combining section 100 are arranged in a row when viewed from the positive direction of the x-axis (an example of the emission direction) (see FIG. 4, etc.). This makes it possible to further narrow the effective area of ​​the optical path combining section 100, thereby enabling the light source device to be further miniaturized.

[0020] Here, the conjugate image is a focusing area where the light emitted from the light source LS is focused. In addition, when the light source LS is a laser light source, the conjugate image is a focusing area of ​​the light emitted from the laser light source. In addition, when the light source LS includes an excitation light source and a wavelength conversion unit, the conjugate image is a focusing area of ​​the light emitted from the wavelength conversion unit.

[0021] Moreover, the conjugate image of light source LS3 is preferably formed near the transmitting section 105. The conjugate images of light source LS1 and light source LS2 are preferably formed near the reflecting surfaces 101 and 102, respectively. The conjugate images of light source LS1 and light source LS2 are preferably formed so as to overlap with the reflecting surfaces 101 and 102. This makes it possible to further narrow the effective area of ​​the optical path combining section 100, thereby enabling the light source device to be further miniaturized.

[0022] In addition, it is preferable that a conjugate image of the light source LS3 is formed between the conjugate image of the light source LS1 and the conjugate image of the light source LS2. This makes it possible to arrange the light path combining unit 100 symmetrically when viewed from the emission direction, thereby making it possible to reduce the layout size of the light source device.

[0023] In this embodiment, the light guiding optical device forms all of the conjugate images of the light sources LS1 to LS3 in the light path synthesis section 100, but is not limited to this as long as at least one of the conjugate images of the light sources LS1 to LS3 is formed in the light path synthesis section 100. Also, in this embodiment, the light emitted from the light sources LS1 to LS3 is condensed to the light path synthesis section 100, but is not limited to this and may be parallel or divergent light with respect to the light path synthesis section 100.

[0024] The optical path combining unit 100 shown in Fig. 1 uses the reflecting surfaces 101 and 102 as an example of a deflection unit that deflects the light incident from the light sources LS1 and LS2 in the emission direction, but is not limited to this as long as it deflects the light incident from the light sources LS1 and LS2 in the emission direction. For example, as shown in Fig. 2, the optical path combining unit 100 may have refracting surfaces 103 and 104 as deflection units that deflect the light incident from the light sources LS1 and LS2 in the emission direction.

[0025] 2, the refracting surface 103 is an example of a first deflection unit that refracts (an example of deflection) light incident from light source LS1 (an example of a first light), in other words, light incident from the negative direction of the z axis, in the positive direction of the x axis (an example of an emission direction). The refracting surface 104 is an example of a second deflection unit that refracts (an example of a deflection) light incident from light source LS2 (an example of a second light), in other words, light incident from the positive direction of the z axis, in the positive direction of the x axis.

[0026] In the present embodiment, the reflecting surfaces 101 and 102 or the refracting surfaces 103 and 104 are used as an example of the first deflection unit and the second deflection unit, but the reflecting surfaces and the refracting surfaces may be combined. For example, the reflecting surface 101 may be used as an example of the first deflection unit, and the refracting surface 104 may be used as an example of the second deflection unit.

[0027] 3, the light tunnel LT is provided immediately after the light path combining unit 100 in the optical path of the light emitted from the light sources LS1 to LS3. The light tunnel LT is an example of a light homogenizing element that guides and emits the light emitted from the light path combining unit 100. In the present embodiment, the inside of the light tunnel LT may be a light guide path in which multiple reflective surfaces are bonded together, a glass rod that guides light using total reflection, or the like.

[0028] 4 and 5 are diagrams showing an example of the intensity distribution of light irradiated to the entrance of the light tunnel in the light source device according to this embodiment. In this embodiment, the intensity distribution of the light from the three light sources LS1 to LS3 incident on the entrance of the light tunnel LT is the same as shown in Fig. 4, but the intensity distribution of the light from the three light sources LS1 to LS3 does not have to be the same intensity distribution, size, or shape.

[0029] For example, regarding the light intensity distribution of the three light sources LS1 to LS3 incident on the entrance of the light tunnel LT, the light intensity distribution of the light source LS3 may be smaller than the light intensity distributions of the light sources LS1 and LS2 as shown in Fig. 5. In other words, among the conjugate images of the light sources LS1 to LS3 formed in the optical path combining unit 100, the conjugate image of the light source LS3 may be smaller than the conjugate images of the light sources LS1 and LS2.

[0030] In this embodiment, the conjugate images of the light sources LS1 to LS3 formed in the optical path combining unit 100 have a shape elongated in one direction in the image plane (e.g., a rectangle or an ellipse) as shown in Fig. 4 and Fig. 5. In this embodiment, all the conjugate images of the light sources LS1 to LS3 have a shape elongated in one direction, but it is sufficient that at least one of the conjugate images of the light sources LS1 to LS3 has a shape elongated in one direction.

[0031] 6 to 8 are diagrams for explaining an example of the configuration of the light guide optical device according to the present embodiment. In the present embodiment, as shown in Figs. 6 to 8, at least one light source (here, light source LS3) among light sources LS1 to LS3 may be a semiconductor laser array LDa (an example of a laser light source). As shown in Figs. 6 to 8, the semiconductor laser array LDa has light-emitting sections LDc that emit laser light and lenses LDL provided for each of the light-emitting sections LDc.

[0032] 7 and 8, it is preferable that the longitudinal direction of the light-emitting portion LDc of the semiconductor laser array LDa coincides with the longitudinal direction of the transmission portion 105 of the optical path combining portion 100. In this embodiment, the light-emitting portion LDc has a rectangular shape, and is disposed so that its longitudinal direction coincides with the longitudinal direction of the transmission portion 105 formed between the reflection surfaces 101 and 102.

[0033] In the present embodiment, the light source device has a single semiconductor laser array LDa, but may have a plurality of semiconductor laser arrays LDa. In this case, the wavelengths of the laser beams emitted from the plurality of semiconductor laser arrays LDa may be the same or different from each other.

[0034] 6 to 8, the light source LS3 is configured by a semiconductor laser array LDa, but the present invention is not limited to this as long as at least one of the light sources LS1 to LS3 is a laser light source such as a semiconductor laser array LDa. In this case, it is preferable that the longitudinal direction of the light emitting section LDc of the semiconductor laser array LDa corresponds to the longitudinal direction of any one of the first deflection section, the second deflection section, and the transmission section into which the light from the semiconductor laser array LDa is incident.

[0035] 9 is a diagram for explaining an example of a light source included in the light-guiding optical device according to the present embodiment. In the present embodiment, the light sources LS1 to LS3 have equivalent configurations, so here, an example of the configuration of the light source LS1 will be explained.

[0036] In this embodiment, the light source LS1 includes an excitation light source LD1 and a wavelength conversion unit F1. The excitation light source LD1 is an example of an excitation light source that emits excitation light. The excitation light source LD1 is a light source such as a semiconductor laser, and may be configured as an array. The light source LS1 also includes a light guiding unit that guides the excitation light emitted from the excitation light source LD1 to the wavelength conversion unit F1.

[0037] The wavelength conversion unit F1 is, for example, a phosphor, and is excited by the excitation light emitted from the excitation light source LD1 to emit light (fluorescent light) with a broader band than that of the excitation light source LD1. That is, the wavelength conversion unit F1 is an example of a wavelength conversion unit that converts the excitation light incident from the excitation light source LD1 into light of a different wavelength range and emits the light. Furthermore, the light source LS1 includes a means for collecting the light emitted from the wavelength conversion unit F1 and the light of the excitation light source LD1 reflected by the wavelength conversion unit F1 on the reflection surface 101.

[0038] The light emitted from light source LS1 in a concentrated manner is reflected in the positive direction of the x-axis by reflecting surface 101 and enters light tunnel LT. As described above, light tunnel LT may be a light guide path having multiple reflecting surfaces bonded together inside, or a glass rod that guides light using total reflection.

[0039] The light emitted from light source LS2 is reflected in the positive direction of the x-axis by reflective surface 102 and enters light tunnel LT, while the light emitted from light source LS3 passes through transmission section 105 provided between reflective surfaces 101 and 102 and directly enters light tunnel LT. With the above configuration, the light from light sources LS1 to LS3 in three directions is combined.

[0040] 10 and 11 are diagrams for explaining other examples of the light source included in the light-guiding optical device according to the present embodiment. In the present embodiment, at least one light source LS among the three light sources LS1 to LS3 may be a light source having an excitation light source and a wavelength conversion unit, and the other light source LS may be a light source that emits light in a narrower wavelength range than the light source having the excitation light source and the wavelength conversion unit.

[0041] Here, the light source device according to the present embodiment includes a light source LS1, a light source LS2 equivalent to the light source LS1, and a light source LS3, as shown in FIG. 10. The light source LS1 has a configuration similar to that of the light source LS1 shown in FIG. 9. The light source LS3 is a light source that emits light in a narrower wavelength band than the light source LS1, and may be, for example, a light source having a semiconductor laser, a single light-emitting element, or an array of light-emitting elements. As shown in FIG. 10, the light emitted from the light source LS3 is collected by a collecting lens, passes through a transmission portion 105 between the reflecting surface 101 and the reflecting surface 102, and enters a light tunnel LT, thereby enabling the light emitted from the light sources LS1 to LS3 to be multiplexed.

[0042] 11, the light source LS3 may have a plurality of light sources LS3a and LS3b that emit light having a narrower wavelength range than the light emitted from the light source LS1. The light emitted from the light source LS3a and the light source LS3b may have the same wavelength or different wavelengths, and may be composed of a single light-emitting element or an array of light-emitting elements.

[0043] In this case, the light source device deflects the light emitted from each of the light sources LS3a and LS3b, or combines the optical paths using the light source wavelength characteristics of the light emitted from each of the light sources LS3a and LS3b. The light source device then passes the light emitted from the light sources LS3a and LS3b through the transmission section 105 between the reflecting surface 101 and the reflecting surface 102 using a condenser lens, and enters the light tunnel LT, thereby realizing the combination of the light emitted from the light sources LS1 to LS4. Note that the combination of the light emitted from each of the light sources LS3a and LS3b may be achieved simply by using a half mirror.

[0044] The intensity of the light emitted from the light source LS3 in Fig. 10 and the light sources LS3a and LS3b in Fig. 11 can be made smaller than the intensity of the light emitted from the light sources LS1 and LS2. This is because the light sources LS3, LS3a, and LSab emit light of the wavelengths of the respective light sources LS3, LS3a, and LS3b without including a wavelength conversion unit and emit light of a narrow wavelength band, so that the light emitted from the light sources LS3, LS3a, and LS3b can be combined with high efficiency. By reducing the intensity of the light emitted from the light sources LS3, LS3a, and LS3b, a low-output light source LS can be used, and the entire light source device including the light source LS can be further miniaturized.

[0045] 12 is a diagram for explaining another example of the light source included in the light-guiding optical device according to the present embodiment. In the present embodiment, at least one light source LS among the three light sources LS1 to LS3 may be a light source having an excitation light source and a wavelength conversion unit, and the other light source LS may be a light source that emits light in a narrower wavelength range than the light source having the excitation light source and the wavelength conversion unit.

[0046] In this embodiment, the light source device may include at least one light source LS1 having an excitation light source LD1 and a wavelength conversion unit F1, and light sources LS2 and LS3 that emit light in a narrower wavelength range than the light source LS1, as shown in Fig. 12. The light source device can also combine the light emitted from the three light sources LS1 to LS3 in the optical path combining unit 100.

[0047] Light source LS1 has a configuration similar to that of light source LS1 shown in FIG. 9. On the other hand, light sources LS2 and LS3 are light sources that emit light in a narrower wavelength range than the light emitted by light source LS1. The light emitted from each of light sources LS2 and LS3 may have the same wavelength or different wavelengths. Furthermore, light sources LS2 and LS3 may have a single light-emitting element or an array of light-emitting elements. Furthermore, light sources LS2 and LS3 may be light sources that combine the optical paths of light emitted from multiple light sources.

[0048] Light source LS1 emits light so that it is focused on reflecting surface 101. The light emitted from light source LS1 is reflected by reflecting surface 101 in the positive direction of the x-axis and enters light tunnel LT. The interior of light tunnel LT may be a light guide path made of multiple reflecting surfaces bonded together, or a glass rod that guides light using total reflection.

[0049] Light emitted from light source LS2 is reflected in the positive direction of the x-axis by reflective surface 102 and enters light tunnel LT. Light emitted from light source LS3 passes through transmission section 105 between reflective surface 101 and reflective surface 102 and directly enters light tunnel LT. As in the above configuration, the light source device according to the present embodiment may combine light emitted from one light source LS having a wavelength conversion section F1 and light emitted from at least two light sources LS that emit light in a narrower wavelength range than the light source LS.

[0050] Fig. 13 is a diagram for explaining another example of the light source included in the light guiding optical device according to the present embodiment. In the present embodiment, as shown in Fig. 13, the light source device can use light sources (for example, laser light sources) that emit light in a narrow wavelength range as the light sources LS1 to LS3. In this case, the light emitted from the light sources LS1 to LS3 can have the same wavelength or different wavelengths. Furthermore, the light sources LS1 to LS3 can be a single light emitting element or an array of light emitting elements. Furthermore, the light sources LS1 to LS3 can be a light source that combines the optical paths of the light emitted from a plurality of light sources.

[0051] Light emitted from light source LS1 is collected by a collecting lens, reflected by reflecting surface 101 in the + direction of the x-axis, and enters light tunnel LT. The interior of light tunnel LT may be a light guide path made of multiple reflecting surfaces bonded together, or a glass rod that guides light using total reflection.

[0052] The light emitted from light source LS2 is collected by the collecting lens, reflected by reflecting surface 102 in the + direction of the x-axis, and enters the light tunnel LT. The light emitted from light source LS3 is collected by the collecting lens, passes through transmission section 105 between reflecting surface 101 and reflecting surface 102, and directly enters the light tunnel LT. As configured as described above, the light source device according to this embodiment may combine light emitted from three light sources LS with narrow wavelength ranges in the optical path combining section 100.

[0053] 14 and 15 are diagrams showing an example of the configuration of a prism included in the light-guiding optical device according to the present embodiment. FIG. 16 and FIG. 17 are diagrams showing an example of the configuration of the light-guiding optical device according to the present embodiment. In the present embodiment, the light path synthesis unit 100 may be a prism P (an example of an optical element) having at least two reflecting surfaces 101 and 102 and a transmitting portion 105, as shown in FIG. 14 and FIG. 15. Here, the transmitting portion 105 has a transmitting surface 105a and a transmitting surface 105b, as shown in FIG. 14 and FIG. 15. In the present embodiment, the light path synthesis unit 100 is realized by a single prism P, but may be realized by combining a plurality of prisms.

[0054] When the optical path combining unit 100 is configured with a single prism P, the transmitting surface 105a can be adjacent to the reflecting surface 101 and the reflecting surface 102 without any gap. As a result, there is no optically unnecessary portion between the transmitting surface 105a and the reflecting surface 101 and the reflecting surface 102, and the light can be combined efficiently. In addition, the dimensional accuracy of the angle, width, etc. of the reflecting surface 101, the reflecting surface 102, and the transmitting unit 105 can be improved by the machining accuracy of the single prism P. As a result, the assembly of multiple parts is eliminated, and the optical path combining unit 100 can be configured more simply.

[0055] Even when the light path combining unit 100 is realized by a prism P, the reflecting surfaces 101, 102 of the prism P reflect the light emitted from the light sources LS1, LS2 in the + direction of the x-axis, respectively, and guide the light to the light tunnel LT. Moreover, the light emitted from the light source LS3 is transmitted (passes) through the transmitting surfaces 105a, 105b, and then enters the light tunnel LT. With the above configuration, the light source device according to this embodiment combines the light paths of the light emitted from the three light sources LS1 to LS3 by an optical element (light path combining unit 100) constituted by a prism P having at least two reflecting surfaces 101, 102.

[0056] 18 and 19 are diagrams showing other examples of the prism included in the light-guiding optical device according to the present embodiment. In the present embodiment, the light path synthesis unit 100 may be a prism P having reflecting surfaces 101 and 102 and transmitting surfaces 105a, 105b, 302, and 306, as shown in Fig. 18. The reflecting surface 101 is a reflecting surface provided inside the prism P, and reflects the light emitted from the light source LS1 and transmitted through the transmitting surface 302 in the + direction of the x-axis.

[0057] When the optical path combining unit 100 is configured with a single prism P, the transmitting surface 105a can be adjacent to the reflecting surface 101 and the reflecting surface 102 without any gap. As a result, there is no optically unnecessary portion between the transmitting surface 105a and the reflecting surface 101 and the reflecting surface 102, and the light can be combined efficiently. In addition, the dimensional accuracy of the angle, width, etc. of the reflecting surface 101, the reflecting surface 102, and the transmitting unit 105 can be improved by the machining accuracy of the single prism P. As a result, the assembly of multiple parts is eliminated, and the optical path combining unit 1000 can be configured more simply.

[0058] Furthermore, the reflecting surface 102 is a reflecting surface provided inside the prism P, and reflects the light emitted from the light source LS2 and transmitted through the transmitting surface 306 in the + direction of the x-axis. The transmitting surfaces 105a and 105b transmit the light emitted from the light source LS3 in the + direction of the x-axis and guide the light to the light tunnel LT.

[0059] In this embodiment, the optical path combining unit 100 can also be realized by a prism P in which the reflecting surfaces shown in FIG. 18 are replaced with refracting surfaces 103 and 104, as shown in FIG. 19. The refracting surface 103 refracts the light emitted from the light source LS1 in the + direction of the x-axis. The refracting surface 104 refracts the light emitted from the light source LS2 in the + direction of the x-axis. The transmitting surfaces 105a and 105b transmit the light emitted from the light source LS3 in the + direction of the x-axis and guide it to the light tunnel LT.

[0060] In the prism P shown in Figures 18 and 19, a reflective surface or a refracting surface is used as a deflection section that deflects the light emitted from light sources LS1 and LS2 in the positive direction of the x-axis, but it is also possible to realize the deflection section by combining a reflective surface and a refracting surface.

[0061] 20 to 22 are diagrams showing other examples of the light path combining section of the light guide optical device according to the present embodiment. In the present embodiment, the light path combining section 100 may include an optical element 401 having a reflecting surface 101 and an optical element 402 having a reflecting surface 102, as shown in FIG.

[0062] 21, the optical path combining unit 100 may include an optical element 501 having a reflecting surface 101 therein, and an optical element 502 having a reflecting surface 102 therein. Here, the optical element 501 has a transmitting surface 503 that transmits light emitted from the light source LS1, and a transmitting surface 505 that transmits light reflected by the reflecting surface 101. In addition, the optical element 502 has a transmitting surface 507 that transmits light emitted from the light source LS2, and a transmitting surface 508 that transmits light reflected by the reflecting surface 102.

[0063] 22, the optical path combining unit 100 may include an optical element 701 having a refractive surface 103 and an optical element 702 having a refractive surface 104. Here, the optical element 701 has a transmitting surface 705 that transmits the light refracted by the refractive surface 103. In addition, the optical element 702 has a transmitting surface 706 that transmits the light refracted by the refractive surface 104.

[0064] FIG. 23 is a diagram showing another example of the light guiding optical device according to the present embodiment. As shown in FIG. 23, the light source device according to the present embodiment may have an optical waveguide 2301 (for example, an optical fiber) which is an example of a light guiding means for guiding the light emitted from the light source LS3 in the + direction of the x axis. As shown in FIG. 23, the light guided by the optical waveguide 2301 is emitted in the + direction of the x axis so as to travel straight between the reflecting surface 101 and the reflecting surface 102. As shown in FIGS. 20 to 23, when the optical path combining unit 100 is composed of a plurality of optical elements, no member is arranged in the transmitting unit 105, so that the light emitted from the light source LS3 is not lost. As a result, the light emitted from the light source LS3 can be combined with high efficiency.

[0065] Fig. 24 is a diagram showing an example of the configuration of an image projection device according to this embodiment. The image projection device according to this embodiment is, for example, a projector, and includes an illumination optical system 2401, an optical modulator 2402, and a projection optical system 2403 as shown in Fig. 24.

[0066] The illumination optical system 2401 is an example of an optical device having the above-mentioned light sources LS1 and LS2, the optical path combining unit 100, and the light tunnel LT. The illumination optical system 2401 emits light to the optical modulator 2402 from the exit of the light tunnel LT.

[0067] The optical modulator 2402 is a liquid crystal, a DMD, or the like, and emits light beams spatially modulated by the optical modulator 2402 to the projection optical system 2403. That is, the optical modulator 2402 is an example of a spatial modulation element that receives light emitted from the illumination optical system 2401 and emits image light. The projection optical system 2403 projects the light (image light) emitted from the optical modulator 2402 as a projection image by a projection lens onto a subject such as a screen. This allows the image projection device according to this embodiment to fulfill the function of a projector.

[0068] In this way, the light guide optical device, light source device, and image projection device according to the present embodiment can reduce loss caused by overlapping of the condensed parts (conjugate images) of the light emitted from the light sources LS1 to LS3 on the reflecting surface 101, the reflecting surface 102, and the transmitting part 105. As a result, it becomes possible to combine the light from three or more light sources LS with high efficiency. [Explanation of symbols]

[0069] 100 Optical path combining section 101,102 Reflective surface 103,104 Refractive Surface 105 Transparent part 105a,105b Transparent surface P Prism 2301 Optical waveguide 2401 Illumination optical system 2402 Optical Modulator 2403 Projection optical system F1 Wavelength conversion section LS1, LS2, LS3, LS3a, LS3b light source LT Light Tunnel LDa Semiconductor laser array LDc light emitting part LDL Lens LD1 Excitation Light Source [Prior art documents] [Patent documents]

[0070] [Patent Document 1] JP 2006-010741 A [Patent Document 2] Patent No. 6094866

Claims

1. a light guide optical device including a light path combining unit that combines light incident from three different directions and outputs the combined light in an emission direction; A first light source that emits a first light; A second light source that emits a second light; a third light source that emits a third light, The optical path synthesis unit includes: a first deflection unit that deflects the first light incident from a first direction to an exit direction; a second deflection unit that deflects the second light incident from a second direction different from the first direction toward the emission direction; a transmission portion that transmits the third light incident from a third direction different from the first direction and the second direction, toward the emission direction, the transmission section is located between the first deflection section and the second deflection section, The light guiding optical device includes: forming a conjugate image of the first light source, the second light source, and the third light source on the optical path combining section; the conjugate images of the first light source, the second light source, and the third light source are arranged in a line when viewed from the emission direction; A light source device, wherein the conjugate image of the third light source is smaller than the conjugate image of the first light source and the conjugate image of the second light source.

2. The light source device according to claim 1 , wherein the light-guiding optical device forms the conjugate image of the third light source between the conjugate image of the first light source and the conjugate image of the second light source.

3. The light source device according to claim 1 , wherein the third light travels straight in the emission direction and has an intensity lower than that of the first light and the second light.

4. A light-guiding optical device having a light path synthesis unit that synthesizes light incident from three different directions and outputs the light in an emission direction; A first light source that emits a first light; A second light source that emits a second light; a third light source that emits a third light, The optical path synthesis unit includes: a first deflection unit that deflects the first light incident from a first direction to an exit direction; a second deflection unit that deflects the second light incident from a second direction different from the first direction toward the emission direction; a transmission portion that transmits the third light incident from a third direction different from the first direction and the second direction, toward the emission direction, the transmission section is located between the first deflection section and the second deflection section, The light guiding optical device includes: forming a conjugate image of at least one of the first light source, the second light source, and the third light source on the optical path combining unit; A light source device, wherein the conjugate image of at least one of the first light source, the second light source, and the third light source has a shape that is elongated in one direction within an image plane.

5. 5. The light source device according to claim 1, wherein the first light source, the second light source, and the third light source include an excitation light source that emits excitation light, and a wavelength conversion unit that converts the excitation light incident from the excitation light source into light of a different wavelength range and emits the light.

6. 5. The light source device according to claim 1, wherein at least one of the first light source, the second light source, and the third light source is a light source including an excitation light source that emits excitation light, and a wavelength conversion unit that converts the excitation light incident from the excitation light source into light of a different wavelength range and emits the light, and at least one other light source emits light of a wavelength range narrower than the wavelength range.

7. A light-guiding optical device having a light path synthesis unit that synthesizes light incident from three different directions and outputs the light in an emission direction; A first light source that emits a first light; A second light source that emits a second light; a third light source that emits a third light, The optical path synthesis unit includes: a first deflection unit that deflects the first light incident from a first direction to an exit direction; a second deflection unit that deflects the second light incident from a second direction different from the first direction toward the emission direction; a transmission portion that transmits the third light incident from a third direction different from the first direction and the second direction, toward the emission direction, the transmission section is located between the first deflection section and the second deflection section, the light guide optical device forms a conjugate image of at least one of the first light source, the second light source, and the third light source in the light path combining section; At least one of the first light source, the second light source, and the third light source includes a laser light source; A light source device, wherein a longitudinal direction of a light emitting portion of the laser light source corresponds to a longitudinal direction of any one of the first deflection portion, the second deflection portion, and the transmission portion, into which light from the laser light source is incident.

8. A light source device described in any one of claims 1 to 7, wherein the first deflection portion and the second deflection portion are optical elements having a reflective surface or a refractive surface.

9. A light source device described in any one of claims 1 to 7, wherein the first deflection portion, the second deflection portion, and the transmission portion are a single optical element.

10. A light source device described in any one of claims 1 to 8, having an optical waveguide that guides the third light in the emission direction.

11. The light source device according to claim 1 , further comprising a light uniformizing element that guides and emits the light emitted from the light path combining portion.

12. an illumination optical system having the light source device according to claim 11; a spatial modulation element that receives light emitted from the illumination optical system and emits image light; a projection optical system that projects the image light onto an object; An image projection device comprising:

Images