JP2008164674A - Light source device, image display device, monitor device, lighting device - Google Patents

Abstract

[PROBLEMS] To improve safety during use of a laser light source device. A part of infrared laser light (infrared laser light 311) is not converted by a second harmonic generation element 110, and the resonance mirror 120 The light enters the reflective film 121. The reflective film 121 of the resonant mirror 120 reflects a part of the incident infrared laser light 311 and transmits the remaining part (transmitted infrared laser light 311a). Part of the transmitted infrared laser light 311 a is reflected by the reflective film 250 formed on the exit surface of the reflective film 121 (reflected infrared laser light 311 b), and the remaining part is transmitted through the reflective film 250. At least a part of the transmitted infrared laser beam 311a is reflected by the reflection films 251 to 254 formed on the incident surface and the emission surface of each member while passing through the invisible light absorbing member 230 and the optical path changing optical element 240. Is done. Therefore, since the amount of the infrared laser light is gradually reduced every time it passes through the optical element, leakage to the outside is suppressed.
[Selection] Figure 2

Description

  The present invention relates to a light source device, an image display device including the light source device, a monitor device, and an illumination device.

  2. Description of the Related Art Image display devices that display images by irradiating spatial light modulation devices such as light valves and digital mirror devices (DMDs) with illumination light from a light source device are used. A laser light source device that emits laser light may be used as the light source device. Some laser light source devices have an opening for laser light emission formed in a direction substantially perpendicular to or substantially parallel to a base plate to which a light source is attached.

  The laser light source device includes a light source that outputs infrared light having a wavelength twice that of visible light (red laser light, green laser light, and blue laser light), and 2 that converts incident light to ½ wavelength. Some have second harmonic generation elements. Infrared light output from the light source can be converted into light having a half wavelength of infrared light through the second harmonic generation element, and visible light can be obtained. By doing so, visible light having a high light intensity can be emitted.

JP 2002-76476 A

  However, the conversion efficiency of the second harmonic generation element is about 40 to 50%, and not all infrared light incident on the second harmonic generation element is converted into visible light having a ½ wavelength. Therefore, infrared light that has passed through the second harmonic generation element without being converted may be emitted to the outside of the laser light source device together with visible light via various optical elements arranged on the optical axis. . From the viewpoint of safety, reduction of infrared light output to the outside of the laser light source device is desired.

  The above-mentioned problem is not limited to an image display device using a laser light source device, but may also occur in a monitor device or a lighting device using a laser light source device.

  The present invention has been made in view of the above-described problems, and aims to improve safety when using a laser light source device.

In order to solve at least a part of the problems described above, a first aspect of the present invention provides a light source device. The light source device of the first aspect is
A light source;
A cover that covers the light source, formed of a material that does not transmit the laser light output from the light source, and formed with an opening for emitting at least part of visible light out of the light included in the laser light;
At least one optical element disposed on the optical axis of the light source device and guiding at least part of the light output from the light source to the opening;
And a non-visible light reflecting member that is disposed on at least one of the incident surface and the emission surface of the optical element and reflects at least part of the non-visible light included in the light output from the light source. .

  Since the light source device of the above aspect includes the invisible light reflecting member, at least a part of the invisible light included in the laser light passing on the optical axis is different from the direction in which the opening is formed. Can be reflected. Therefore, the invisible light contained in the laser light is reduced when passing through the optical element. Therefore, leakage of invisible light to the outside can be suppressed, and safety can be improved.

In the light source device of the first aspect,
The optical element may include a non-visible light absorbing member formed of a material that absorbs at least part of the non-visible light.

  According to the above aspect, since at least a part of the invisible light included in the laser light passing on the optical axis can be absorbed, it is possible to improve the suppression of leakage of the invisible light to the outside of the light source device.

In the light source device of the first aspect,
The direction connecting the light source and the opening is a direction that is substantially perpendicular to or substantially parallel to the base plate to which the light source is attached, and the optical element is substantially perpendicular to the base plate or An optical path changing optical element that changes the traveling direction of the output light traveling in a substantially parallel direction and guides it to the opening may be included.

  According to the above-described aspect, the opening is formed in a direction different from the traveling direction of light substantially parallel or substantially perpendicular to the base plate. Therefore, even when the wavelength dispersion element is damaged or dropped, the opening is formed. The leakage of invisible light from can be suppressed.

In the light source device of the first aspect,
The direction connecting the light source and the opening is a direction different from a substantially vertical direction or a substantially parallel direction with respect to a base plate to which the light source is attached,
The light output from the light source is arranged based on the target traveling direction of the light to travel, has wavelength dispersion, and at least a part of visible light out of the wavelength dispersed light is emitted from the opening to the outside of the light source device. It may include at least one wavelength dispersion optical element configured as described above.

  Since the light source device of the above-described aspect includes the wavelength dispersion optical element, it can separate light of various wavelengths included in the laser light output from the light source by wavelength. Therefore, according to the light source device described above, only visible light separated by the wavelength dispersion element can be guided out of the opening, and invisible light can be kept inside the cover. Furthermore, according to the light source device of the above aspect, since the direction connecting the opening and the light source is different from the target output direction of the light source, even if the wavelength dispersion element is damaged or dropped, Invisible light leakage can be suppressed.

In the light source device of the first aspect,
The wavelength dispersion optical element may include a prism.

  The prism can separate light of various wavelengths included in the light output from the light source at a refraction angle corresponding to the wavelength. Therefore, according to the light source device of the above-mentioned aspect, since visible light and invisible light can be advanced in different directions, leakage of invisible light can be suppressed with high accuracy.

  According to a second aspect of the present invention, there is provided an illumination device including the light source device according to the first aspect. According to the 2nd aspect, the illuminating device by which the leakage of invisible light was suppressed can be comprised, and safety | security can be improved.

  A third aspect of the present invention provides a monitor device including the light source device of the first aspect. According to the 3rd aspect, the monitor apparatus with which leakage of invisible light was suppressed can be constituted, and safety can be improved.

  According to a fourth aspect of the present invention, there is provided an image display device comprising the light source device according to the first aspect. According to the 3rd aspect, the image display apparatus with which leakage of invisible light was suppressed can be constituted, and safety can be improved.

  In the present invention, the various aspects described above can be appropriately combined or partially omitted.

A. First embodiment:
A1. System configuration:
In the first embodiment, a projector as an image display device will be described with reference to FIGS. FIG. 1 is an explanatory diagram illustrating the schematic configuration of the projector in the first embodiment. FIG. 2 is an explanatory diagram illustrating the detailed configuration of the light source device according to the first embodiment.

  As shown in FIG. 1, the projector 1000 includes light source devices 10, 20, 30, a uniformizing optical element 50, a light valve 60, a dichroic prism 70, and a projection lens 80.

  The light source devices 10 to 30 are used as light sources for the projector 1000. The light source device 10 outputs red laser light having a wavelength of about 650 nm, the light source device 20 outputs green laser light having a wavelength of about 540 nm, and the light source device 30 outputs blue laser light having a wavelength of about 430 nm. To do. Since laser light is absorbed by various devices, the amount of light output from the semiconductor laser device and the amount of light used for image projection are slightly different. The detailed configuration of the light source devices 10 to 30 will be described in detail later.

  The uniformizing optical element 50 superimposes incident irradiation light to average out luminance unevenness, and reduces the light amount difference between the end portion and the center portion of the screen. By arranging the uniformizing optical element 50, a bright image can be projected on the entire screen. In this embodiment, a diffractive optical element is used as the uniformizing optical element 50.

  The light valve 60 is formed using high temperature polysilicon (HTPS: High Temperature Poly-Silicon), and is an active matrix drive type transmissive liquid crystal panel. The light valve 60 draws an image by controlling incident light.

  The dichroic prism 70 has a configuration in which four triangular prisms are combined to form a rectangular parallelepiped. The dichroic prism 70 combines the red laser light, the green laser light, and the blue laser light that have passed through the light valve 60 to form an image, and project the image. Project to the lens 80.

  The projection lens 80 projects the image projected from the dichroic prism 70 onto the screen 90.

  As described above, the projector 1000 causes the light emitted from the light source devices 10 to 30 to enter the corresponding light valves 60 to form an image, and then synthesizes the light and projects it onto the screen 90. The viewer visually recognizes the image projected on the screen 90.

A2. Detailed configuration of light source device:
With reference to FIG. 2, the detailed structure of the light source device of the first embodiment will be described. Since the light source devices 10 to 30 are configured similarly except for the wavelength of the emitted laser light, the light source device 10 will be described as an example in the first embodiment.

  As shown in FIG. 2, the light source device 10 includes a semiconductor laser device 100a as a laser light source, a second harmonic generation element 110, a resonator 120, a cover 200, a tubular member 210, an invisible light absorbing member 230, and an optical path changing optical. An element 240 and reflective films 250 to 254 are provided.

  The semiconductor laser device 100a of the light source device 10 outputs laser light having a wavelength of about 1300 nm, which is twice the peak wavelength of red laser light of about 650 nm. The semiconductor laser device of the light source device 20 outputs laser light having a wavelength of about 1080 nm, which is twice the peak wavelength of green laser light, which is about 540 nm, and the semiconductor laser device of the light source device 30 has a peak wavelength of blue laser light. The laser beam of about 860 nm, which is twice the value of about 430 nm, is output. That is, each of the semiconductor laser devices of the light source devices 10 to 30 outputs infrared laser light. In the present specification, hereinafter, visible light (including red light, green light, and blue light) or visible laser light (including red laser light, green laser light, and blue laser light) is about 360 nm to about 830 nm. Light having a wavelength of less than about 360 nm (for example, ultraviolet light) or light having a wavelength of greater than about 830 nm (for example, infrared light) is included in invisible light.

  The second harmonic generation element 110 is a non-linear optical element that converts incident light into a substantially half wavelength. Light that is output from the semiconductor laser device 100 a and travels toward the resonator 120 passes through the second harmonic generation element 110, and is converted into light having a half wavelength. The wavelength conversion efficiency by the second harmonic generation element 110 has a non-linear characteristic. For example, the higher the intensity of the laser light incident on the second harmonic generation element 110, the higher the conversion efficiency. The conversion efficiency of the second harmonic generation element 110 is about 40 to 50%. The infrared laser light output from each of the semiconductor laser devices of the light source devices 10 to 30 is converted into visible light by passing through the second harmonic generation element 110.

  The resonator 120 is a resonator composed of deposition type reflection films 121 and 122 formed by laminating dielectric multilayer films. VBG is a deposition hologram mirror and is used only for the external resonator. The dielectric multilayer film includes a plurality of inorganic films having different refractive indexes, such as titanium dioxide, silicon dioxide, zinc sulfide, and magnesium fluoride. Hereinafter, in this specification, the deposition-type resonator 120b is referred to as a resonance mirror 120. The resonant mirror 120 has a property of selectively reflecting light in a predetermined wavelength range, and the reflected wavelength range is adjusted by changing the film structure (material or film thickness of each laminated inorganic film). be able to. In this embodiment, the resonant mirror 120 reflects light in a predetermined wavelength region including the peak wavelength (650 nm) of red laser light with a high reflectance of about 98%. A reflective film 250 is formed on the exit surface of the resonant mirror 120.

  In addition, a reflection film 250 as an infrared laser light reflecting member is formed on the exit surface of the resonance mirror 120.

The reflection films 250 to 254 are multilayer thin films formed of a material that reflects wavelength selective film infrared laser light that reflects infrared light of 680 nanometers or more. The reflective films 250 to 254 are formed so that the reflectance is 98% or more. The reflection films 250 to 254 are formed of a multilayer film using, for example, silicon dioxide (SiO ₂ ), titanium oxide (TiO ₂ ), or zirconia (ZrO ₂ ). Since infrared laser light has a wavelength that resonates in the resonator, the power of the laser can be increased by returning it to the resonator using a reflective film, while stray light and absorption light in each optical element increases as the distance from the resonator increases. There is a possibility of heat. Therefore, it is preferable to arrange the reflective film at least at a position closest to the resonator. In this embodiment, it is preferable to include at least the reflective film 250.

  The invisible light absorbing member 230 is formed of a material that absorbs infrared light. The non-visible light absorbing member 230 uses, for example, Schott KG3 or BG38 as an infrared light absorbing material. The non-visible light absorbing member 230 is further formed with reflecting films 251 and 252 as infrared laser light reflecting members on the incident surface and the exit surface.

  The optical path changing optical element 240 is a columnar optical element configured to guide incident light to the opening 201. In the optical path changing optical element 240, reflection films 253 and 254 are formed on the entrance surface and the exit surface as infrared laser light reflecting members.

  The cover 200b is a casing formed so as to cover the optical element installed in the light source device 10, and is formed of a material that does not transmit infrared light. The opening 201 of the cover 200b is formed at a position where the direction A connecting the opening 201 and the semiconductor laser device 100b is different from the direction perpendicular to the base plate 101 of the semiconductor laser device 100a.

  The tubular member 210 is a tubular member that is formed of a material that absorbs infrared light and has a cross section that has substantially the same shape as the opening 201. The tubular member 210 is attached so as to face the outside of the cover from the opening 201.

A3. How laser light travels:
A method of traveling the laser beam of the light source device 10 will be described. The laser beam 310 output from the semiconductor laser device 100 a and output almost parallel to the optical axis via the second harmonic generation element 110 and the resonant mirror 120 is an optical path changing optical element 240 via the invisible light absorbing member 230. Is guided to the opening 201 and is emitted to the outside of the light source device 10.

  On the other hand, since the conversion efficiency of the second harmonic generation element 110 is about 40 to 50%, a part of the infrared laser light (infrared laser light 311) is incident on the reflection film 121 of the resonant mirror 120. The reflection film 121 of the resonance mirror 120 reflects a part of the incident infrared laser light 311 and transmits a part thereof (transmission infrared laser light 311a). Part of the transmitted infrared laser light 311 a is reflected by the reflective film 250 formed on the exit surface of the resonant mirror 120 (reflected infrared laser light 311 b), and the remaining part is transmitted through the reflective film 250.

  At least part of the transmitted infrared laser light 311a that has passed through the reflective film 250 passes through the invisible light absorbing member 230 and the optical path changing optical element 240, and is formed on the incident surface and the exit surface of each member. Reflected by the films 251 to 254. Therefore, since the transmitted infrared laser beam 311a passes through the optical element, the amount of light is gradually reduced.

  On the other hand, in the laser light that is output from the semiconductor laser device 100a and travels without entering the second harmonic generation element 110, visible light that is reflected by the side surface of the cover 200b and is emitted from the opening 201 to the outside. There is also laser light incident with a deviation from the target emission direction (infrared laser light 312). At least a part of the infrared laser light 312 is absorbed by the tubular member 210 when it hits the side surface of the tubular member 210.

  According to the first embodiment described above, the reflective film that reflects the infrared light is formed on the optical element included in the light source device, thereby suppressing the enlargement of the light source device, and the infrared light source device outside. Leakage can be suppressed.

  In the light source device of the first embodiment, the opening of the cover is different from the light traveling in a direction substantially horizontal or substantially perpendicular to the base plate of the semiconductor laser device in the direction connecting the opening and the semiconductor laser device. It is formed to be in the direction. As a result, when an optical element installed inside the light source device is damaged or dropped out, it strikes the side of the cover as in the case of the infrared laser beam 314 shown in FIG. Can be suppressed.

B. Second embodiment:
B1. Light source device schematic configuration:
In the second embodiment, a wavelength dispersion optical element is used as a means for preventing leakage of invisible light. A light source device according to a second embodiment will be described with reference to FIGS. FIG. 3 is an explanatory diagram illustrating the schematic configuration of the light source device according to the second embodiment. FIG. 4 is an explanatory diagram for explaining wavelength dispersion of light of a prism as a wavelength dispersion optical element in the second embodiment. FIG. 5 is an explanatory diagram illustrating an aperture in the second embodiment.

  The light source device 10a of the second embodiment includes a semiconductor laser device 100a, a second harmonic generation element 110, a resonant mirror 120, an aperture 130, a cover 200, a tubular member 210, a reflective film 250, a wavelength dispersion optical element 260, and invisible light. An absorbent member 270. Since the semiconductor laser device 100a, the second harmonic generation element 110, the resonant mirror 120, the tubular member 210, and the reflective film 250 have the same functions and configurations as in the first embodiment, description thereof is omitted.

  The wavelength dispersion optical element 260 is an optical element having wavelength dispersion, and emits incident light dispersed by wavelength. Since the refractive index of the material differs depending on the wavelength of the light, light including a plurality of types of light having different wavelengths is refracted at a refractive index corresponding to each wavelength when entering the material having wavelength dispersion. As a result, the direction of the emitted light varies depending on the wavelength. Such a property of dispersing light by using a different refractive index for each wavelength is called wavelength dispersion. In this embodiment, the wavelength dispersion optical element 260 is a prism. Hereinafter, in this specification, the wavelength dispersion optical element 260 is referred to as a prism 260.

  The prism 260 is in a target traveling direction that is a direction in which light output from the semiconductor laser device 100 should travel (in this embodiment, the traveling direction of light traveling in a direction substantially perpendicular to the surface direction of the base plate of the semiconductor laser device). Based on this, the refractive index of light different for each wavelength is taken into consideration, and light having a desired wavelength is arranged to be guided to the opening. That is, the position and angle at which the prism 260 is disposed are appropriately determined according to the size and shape of the prism, the target traveling direction, the position of the opening of the cover, and the desired wavelength of light.

  The invisible light absorbing member 270 is a member formed of a material that absorbs infrared light, and is disposed at least on a portion of the side surface of the cover 200b where the infrared light hits the light dispersed by the prism. . The non-visible light absorbing member 270 is, for example, a metal having heat resistance, high thermal conductivity, and optical infrared light absorption, and is preferably black. The invisible light absorbing member 270 can be formed using, for example, aluminum.

  The aperture 130 is made of a metal member that is a material that absorbs laser light, such as a black anodized aluminum plate, a molded magnesium die-cast structure, a titanium frame, or a heat-resistant resin such as an ABS resin, 5 is a member formed using a polycarbonate material or the like, and passes light traveling along an optical axis connecting the semiconductor laser device 100a and the resonator 120 out of light output from the semiconductor laser device, as shown in FIG. An opening 131 is formed to be formed. In this embodiment, the diameter of the opening 131 is about 1 mm.

B2. How laser light travels:
With reference to FIG. 3 and FIG. 4, how the laser light travels in the light source device 10a will be described. Laser light 320 output from the semiconductor laser device 100 a and output along the optical axis via the second harmonic generation element 110 and the resonant mirror 120 is incident on the prism 260. The laser beam 320 includes an infrared laser beam that is invisible light and a red laser beam that is visible light.

  Here, in this embodiment, as shown in FIG. 4, the incident angle of the laser beam 320 incident on the prism 260 is the incident angle α, the refraction angle of the wavelength of the red laser beam (for example, about 650 nm) is the refraction angle β1, The refraction angle of the wavelength of infrared laser light (for example, about 1300 nm) is expressed as a refraction angle β2.

  As shown in FIG. 4, the red laser beam 321 included in the laser beam 320 incident on the prism 260 at the incident angle α is refracted at the refraction angle β1 and travels through the prism 260 and is output. On the other hand, the infrared laser light 322 included in the laser light 320 is refracted at the refraction angle β2 and travels through the prism 260, and is output in a direction different from the red laser light 321.

  As shown in FIG. 3, the red laser beam 321 passes through the inside of the tubular member 210 through the opening 201 and is output to the outside of the light source device 10a. On the other hand, the infrared laser light 322 is absorbed by the non-visible light absorbing member 270.

  Also, infrared laser light 323 output from the semiconductor laser device 100a and traveling without entering the second harmonic generation element 110 or infrared light output without being converted into a half wavelength by the second harmonic generation element 110 As shown in FIG. 3, light that is not desired to be emitted to the outside, such as 324, is reflected on the side surface of the cover 200 b and is repeatedly reflected on the side surface of the tubular member 210 to be absorbed by the tubular member 210. The light is reflected inside the cover 220b and becomes stray light, which is absorbed by the aperture 130.

  According to the light source device of the second embodiment described above, by arranging the prism in the light source device, light of a plurality of wavelengths can be refracted with different refractive indexes and dispersed by wavelength using wavelength dependency. Accordingly, visible light that is light having a desired wavelength is guided to the opening of the cover, and leakage of invisible light (infrared light) that is light having a wavelength that is not desired to be leaked to the outside can be suppressed, thereby improving safety. .

  In addition, the light source device of the second embodiment includes a non-visible light absorbing member in the emission direction of non-visible light (infrared light) from the prism. Thereby, invisible light can be absorbed and leakage of invisible light to the outside can be suppressed.

  The aperture 130 is preferably shorter than the length of the semiconductor laser device 100a in the vertical direction. Although not shown in the figure, since the semiconductor laser device 100a also outputs the light radially, a part of the light output radially can be absorbed and the generation of stray light can be suppressed.

C. Third Example C1. Light source device schematic configuration:
In the third embodiment, a prism is used as the leakage preventing means for infrared laser light as in the second embodiment. However, in the third embodiment, a plurality of prisms are arranged on the optical axis. About the light source device of the third embodiment. This will be described with reference to FIG. FIG. 6 is an explanatory diagram illustrating the schematic configuration of the light source device according to the third embodiment.

  The light source device 10b of the third embodiment includes a semiconductor laser device 100a, a second harmonic generation element 110, a resonant mirror 120, an aperture 130, a cover 200b, a tubular member 210, reflection films 250, 253, 254, and a wavelength dispersion optical element 260. , 261 and an optical path changing optical element 241. The semiconductor laser device 100a, the second harmonic generation element 110, the resonant mirror 120, the aperture 130, the tubular member 210, the reflection films 250, 253, 254, and the cover 200b are the same as those described in the first to third embodiments. Since the functions and configurations are the same as those of the devices having the same reference numerals among the devices, description thereof will be omitted. In the cover 200b, side surfaces 202 and 203 adjacent to the tubular member 210 are formed of an infrared light absorbing material. Hereinafter, in the present embodiment, the side surfaces 202 and 203 are referred to as absorbers 202 and 203.

C2. How laser light travels:
With reference to FIG. 6, how the laser beam travels in the light source device 10b will be described. Laser light 340 output from the semiconductor laser device 100 a and output substantially parallel to the optical axis via the second harmonic generation element 110 and the resonant mirror 120 is incident on the prism 260. The laser light 320 includes infrared light that is invisible light and visible light.

  The red laser beam 341 included in the laser beam 340 incident on the prism 260 is refracted, travels through the prism 260, and is emitted. On the other hand, the infrared laser light 342 included in the laser light 340 is refracted at a refraction angle different from that of the red laser light 341, travels in the prism 260, and is emitted in a direction different from that of the red laser light 321.

  The red laser beam 341 and the infrared laser beam 342 output from the prism 260 and incident on the prism 261 are refracted at a refraction angle corresponding to the wavelength of each light, and are emitted in different directions.

  The red laser beam 341 output from the prism 261 enters the optical path changing optical element 241 to change the optical path, passes through the inside of the tubular member 210, and is emitted to the outside of the light source device 10b. On the other hand, the infrared laser beam 342 output from the prism 261 is incident on the optical path changing optical element 241 to change the optical path, and is absorbed by the absorber 202.

  Further, infrared laser light output from the semiconductor laser device 100a and traveling without entering the second harmonic generation element 110 or infrared laser light output without being converted into a half wavelength by the second harmonic generation element 110 Is absorbed by the side surfaces of the absorbers 202 and 203 and the tubular member 210 or by the aperture 130.

  According to the third embodiment described above, by arranging a plurality of prisms, the refraction angle of light caused by wavelength dispersion can be expanded. Therefore, the traveling direction of visible light and invisible light can be controlled based on the arrangement and quantity of the prisms. Accordingly, only light with a desired wavelength (visible light in the third embodiment) can be emitted outside the light source device with high accuracy.

  Moreover, since invisible light (infrared light in the third embodiment) can be absorbed by an absorber or an aperture, the invisible light can be prevented from staying in the light source device, and the temperature rise of the light source device can be suppressed.

D. Fourth embodiment:
D1. Light source device schematic configuration:
In the fourth embodiment, a monitor device including a light source device will be described. FIG. 7 is an explanatory diagram illustrating a monitor device 400 according to the fourth embodiment. The monitor device 400 includes a device main body 410 and an optical transmission unit 420. The apparatus main body 410 includes the light source apparatus 10 of the first embodiment described above. As described in the first embodiment, the light source device 10 includes the semiconductor laser device 100a, the second harmonic generation element 110, and the resonance mirror 120.

  The light transmission unit 420 includes two light guides 421 and 422 on the light transmitting side and the light receiving side, respectively. Each light guide 421 and 422 is a bundle of a large number of optical fibers, and can transmit laser light from one end to the other end. The light source device 10 is disposed at one end of the light guide 421 on the light transmitting side, and the diffusion plate 423 is disposed at the other end. The laser light emitted from the light source device 10 is transmitted to the diffusion plate 423 provided at the tip of the light transmission unit 420 through the light guide 421 and is diffused by the diffusion plate 423 to irradiate the subject.

  An imaging lens 424 is also provided at the tip of the light transmission unit 420, and reflected light from the subject can be received by the imaging lens 424. The received reflected light is transmitted to the light guide 422 on the receiving side, and sent to the camera 411 as the imaging means provided in the apparatus main body 410. As a result, the camera 411 can capture an image based on the reflected light obtained by irradiating the subject with the laser light emitted from the light source device 10.

  According to the monitor device 400 configured as described above, the subject can be irradiated by the light source device 10 that suppresses leakage of infrared light. Since the monitor device 400 often uses a human as an imaging target, it is possible to improve the safety of the imaging target and the human who performs the imaging.

E. Modified example

(1) In each of the above-described embodiments, the stray light preventing aperture 130 is disposed between the semiconductor laser device and the second harmonic generation element. The aperture is used for emitting laser light from the semiconductor laser device in the light source device. If it is arranged at any position between the opening and the opening, stray light can be prevented. If it is arranged between the semiconductor laser device and the second harmonic generation element, part of the infrared light emitted radially from the semiconductor laser device can be absorbed with high accuracy, and safety can be improved.

(2) In the fifth embodiment described above, the monitor device 400 uses the light source device 10 of the first embodiment as a light source device. However, various light source devices exemplified in this specification are used instead of the light source device 10. It may be used.

(3) In the first embodiment described above, only the tubular member is formed of a member that absorbs infrared light. For example, you may form the whole side surface of a cover with an infrared-light absorption member.

  As mentioned above, although the various Example of this invention was described, this invention is not limited to these Examples, A various structure can be taken in the range which does not deviate from the meaning.

It is explanatory drawing which illustrates about schematic structure of the projector as an image display apparatus in 1st Example. It is explanatory drawing which illustrates about the detailed structure of the light source device in 1st Example. It is explanatory drawing which illustrates schematic structure of the light source device in 2nd Example. It is explanatory drawing explaining the wavelength dispersion of the light of the prism as a wavelength dispersion optical element in 2nd Example. It is explanatory drawing which illustrates the aperture as a stray light prevention means in 2nd Example. It is explanatory drawing which illustrates schematic structure of the light source device in 3rd Example. It is explanatory drawing which illustrates the monitor apparatus in 4th Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10-30 ... Light source device 10a, 10b ... Light source device 50 ... Uniformation optical element 60 ... Light valve 70 ... Dichroic prism 80 ... Projection lens 90 ... Screen 100, 100a. DESCRIPTION OF SYMBOLS 100b ... Semiconductor laser apparatus 101 ... Base plate 110 ... Second harmonic generation element 120 ... Resonator 121, 122 ... Reflective film 130 ... Aperture 131 ... Opening 200, 200b ... Cover 201 ... Opening 202, 203 ... Absorber 210 ... Tubular Member 230 ... Invisible light absorbing member 240, 241 ... Optical path changing optical element 250-254 ... Reflective film 260, 261 ... Prism 270 ... Invisible light absorbing member 310 ... Laser light 311 ... Infrared laser light 311a ... Transmission infrared laser Light 311b ... Reflected infrared laser light 312, 314 ... Infrared laser light 320, 340 ... Laser light 321-324 ... Red laser light 341 ... Red laser light 342 ... Infrared laser light 400 ... Monitor device 410 ... Device body 411 ... Camera 420 ... Optical transmission part 421, 422 ... Light guy 423 ... the diffusion plate 424 ... imaging lens 1000 ... projector

Claims (8)

A light source device,
A light source;
A cover that covers the light source, formed of a material that does not transmit the laser light output from the light source, and has an opening for emitting at least part of the laser light;
At least one optical element disposed on the optical axis of the light source device and guiding at least part of the light output from the light source to the opening;
It is disposed on at least one of the incident surface and the exit surface of the optical element and reflects at least a part of the invisible light included in the light output from the light source in a direction different from the direction in which the opening is formed. And a non-visible light reflecting member. The light source device according to claim 1,
The optical element includes a non-visible light absorbing member formed of a material that absorbs at least part of non-visible light. The light source device according to claim 1,
The direction connecting the light source and the opening is a direction different from a substantially vertical direction or a substantially parallel direction with respect to a base plate to which the light source is attached,
The optical element includes a light path changing optical element that changes a traveling direction of the output light traveling in a substantially vertical direction or a substantially parallel direction with respect to the base plate and guides it to the opening. The light source device according to claim 1,
The optical element is arranged based on a target traveling direction of light output from the light source, has wavelength dispersion, and at least part of visible light out of the wavelength dispersed light is emitted from the opening to the light source. Including at least one wavelength-dispersing optical element configured to be emitted outside the apparatus;
The target traveling direction is a substantially vertical direction or a substantially horizontal direction with respect to a base plate to which the light source is attached,
The light source device, wherein a direction connecting the light source and the opening is a direction different from the target traveling direction. The light source device according to claim 4,
The wavelength dispersion optical element is a light source device including a prism. An illuminating device provided with the light source device in any one of Claims 1 thru | or 5. A monitor device comprising the light source device according to claim 1. An image display device comprising the light source device according to claim 1.

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