JP2011180477A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device which prevents the deterioration of beam emission efficiency of semiconductor laser and does not leak non-visible light to the external part of the image display device. <P>SOLUTION: The image display device 100 has a dichroic mirror 10a which separates beam paths of a green color laser beam 51 emitted from a green color laser beam source device 1 and an infrared modulation laser beam 55, wherein a thermostat 20a for detecting the infrared modulation laser beam 55 separated by the dichroic mirror 10a and at least the one dichroic mirror 10a are disposed on the external part of the green color laser beam source device 1, and the thermostat 20a is disposed on the extension line of the optical path of the green color laser beam 51 just before being separated by at least the one dichroic mirror 10a. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image display device equipped with a laser light source device using a semiconductor laser.

  In recent years, a technique using a semiconductor laser that supplies laser light has been developed as a light source of an image display device capable of displaying a large screen. Compared with an ultra-high pressure mercury lamp (UHP lamp) conventionally used as a light source of an image display device, a light source using a semiconductor laser has advantages such as high color reproducibility, instant lighting, and long life.

  A conventional laser light source device will be described below. A conventional laser light source device includes a semiconductor laser that emits infrared laser light, wavelength conversion means that converts infrared laser light emitted from the semiconductor laser into half-wavelength visible laser light, and a laser emitted by the wavelength conversion means. It comprises a prism as an optical path separating means for incident light and a cover for housing these. Since the conversion efficiency of the wavelength conversion means is not 100%, the wavelength conversion means emits infrared laser light as invisible light together with visible laser light. Therefore, the prism is provided in the cover and refracts visible laser light and infrared laser light in different directions. Thereby, the optical paths of the visible laser beam and the infrared laser beam are separated, and the optical path of the visible laser beam is changed so as to go to the opening of the cover. Therefore, the laser light source device can output only visible laser light to the outside. Here, the optical path is changed so that the separated infrared laser light is directed to the invisible light absorbing member provided on the inner wall of the cover. Thereby, an infrared laser beam is irradiated and absorbed by a non-visible light absorption member. Further, infrared laser light that is not guided to the invisible light absorbing member by the prism is gradually absorbed by repeating reflection inside the cover. As described above, the laser light source device can prevent leakage of infrared laser light to the outside (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2008-165995

  However, an image display device equipped with a conventional laser light source device using a semiconductor laser has the following two problems.

  The first is to absorb the infrared laser light that is not desired to leak outside the laser light source device by the invisible light absorbing member or by repeating reflection within the cover of the laser light source device. Infrared laser light is also called heat rays, and heats the irradiated area. For this reason, when infrared laser light is absorbed in the laser light source device, the temperature of the laser light source device naturally rises. In general, a semiconductor laser has poor temperature characteristics as compared with a light source such as an LED or a lamp. Therefore, when the temperature of the semiconductor laser rises as the temperature of the laser light source device rises, the light emission efficiency of the semiconductor laser deteriorates.

  The second is to guide infrared laser light and visible laser light in a predetermined direction by refraction by a prism. For example, if the prism is displaced, tilted, or detached from a predetermined position due to a fall of a laser light source device or an image display device on which the laser light source device is mounted, infrared laser light and visible laser light can be guided in a predetermined direction. Can not. Furthermore, depending on how the prism is tilted, the infrared laser light may face the opening of the cover and continue to leak out of the laser light source device. Therefore, even when this laser light source device is mounted on an image display device, the image display device may leak high-power infrared laser light to the outside, which is very dangerous.

  In order to solve these two problems, it is an object of the present invention to provide an image display device that prevents a decrease in the light emission efficiency of a semiconductor laser and that does not leak infrared laser light that is invisible to the outside. And

  In order to achieve the above object, an image display device of the present invention comprises a semiconductor laser that emits invisible light and wavelength converting means that converts the invisible light emitted by the semiconductor laser into visible light, and this wavelength. An image display device comprising: a laser light source device that emits visible light converted by a conversion unit to the outside; and an optical path separation unit that separates optical paths of visible light and invisible light emitted from the laser light source device. In addition, a non-visible light detecting means for detecting non-visible light separated by the optical path separating means and the at least one optical path separating means are provided outside the laser light source device, and are separated by the at least one optical path separating means. The invisible light detecting means is provided on the extension line of the optical path of visible light immediately before the light.

  Since the present invention is configured as described above, the optical paths of the visible light and the invisible light are separated by the optical path separating means provided outside the laser light source device, and the invisible light is irradiated to the invisible light detecting means. . Thereby, since invisible light is not absorbed inside the laser light source device, it is possible to prevent the temperature of the laser light source device from rising, and thus it is possible to prevent a decrease in the light emission efficiency of the semiconductor laser. Further, the invisible light detecting means is provided on the extension of the optical path of the visible light immediately before being separated by the optical path separating means, so that the visible light is reflected by the optical path separating means and the invisible light is transmitted through the optical path separating means. Thus, the optical path is separated. That is, since the optical path of the invisible light is not changed by the optical path separating means, the invisible light can be reliably irradiated to the invisible light detecting means even if the optical path separating means is shifted, tilted, or detached.

1 is a schematic configuration diagram of an image display device equipped with a laser light source device according to Embodiment 1 of the present invention. 1 is a schematic configuration diagram of a laser light source device according to Embodiment 1 of the present invention. Schematic configuration diagram of an image display device equipped with a laser light source device in Embodiment 2 of the present invention Schematic configuration diagram of an image display device equipped with a laser light source device in Embodiment 3 of the present invention

  The first aspect of the present invention comprises a semiconductor laser that emits invisible light and wavelength conversion means that converts the invisible light emitted by the semiconductor laser into visible light, and the visible light that is converted by the wavelength conversion means. An image display device comprising: a laser light source device that emits light to the outside; and an optical path separation unit that separates an optical path between visible light and invisible light emitted from the laser light source device. An invisible light detecting means for detecting invisible light separated by the optical path separating means and the at least one optical path separating means are provided outside, and an optical path of visible light immediately before being separated by the at least one optical path separating means The present invention relates to an image display device characterized in that the invisible light detection means is provided on an extended line of the above.

  According to the first aspect of the present invention, the optical path between the visible light and the invisible light is separated by the optical path separating means provided outside the laser light source device, and the invisible light is irradiated to the invisible light detecting means. Thus, since the invisible light is not absorbed inside the laser light source device, the temperature rise of the laser light source device can be prevented. Therefore, it is possible to prevent a decrease in the light emission efficiency of the semiconductor laser. Further, the invisible light detecting means is provided on the extension of the optical path of the visible light immediately before being separated by the optical path separating means, so that the visible light is reflected by the optical path separating means and the invisible light is transmitted through the optical path separating means. Thus, the optical path is separated. That is, since the optical path of the invisible light is not changed by the optical path separating means, the invisible light can be reliably irradiated to the invisible light detecting means even if the optical path separating means is shifted, tilted, or detached.

  According to a second aspect of the present invention, the laser light source device, the optical path separation unit, and the invisible light detection unit are arranged in a substantially straight line.

  According to the second aspect of the present invention, the optical path separation means and the invisible light detection means are provided in the output direction of the laser light source device. For this reason, the invisible light passes through the optical path separating means and is irradiated to the invisible light detecting means. Therefore, even if the optical path separating means is displaced, tilted, or detached, the invisible light can be reliably irradiated to the invisible light detecting means.

  According to a third aspect of the present invention, there is provided an optical path changing means for changing an optical path of visible light and invisible light emitted from the laser light source device, and on the optical path of visible light whose optical path has been changed by the optical path changing means. The optical path separating means is provided, and the invisible light detecting means is provided on an extension of the optical path of visible light immediately before being separated by the optical path separating means.

  According to the third aspect of the present invention, since the laser light source device is heated with invisible light, it is possible to prevent a decrease in the light emission efficiency of the semiconductor laser. Further, even if the optical path separating means is shifted, tilted, or detached, the invisible light can be reliably irradiated to the invisible light detecting means.

  According to a fourth aspect of the present invention, a plurality of the optical path separating means are provided, and the invisible light detecting means is provided on an extension line of the optical path of visible light immediately before being separated by each of the optical path separating means. .

  According to the fourth aspect of the present invention, by providing a plurality of optical path separating means and invisible light detecting means, the optical paths of visible light and invisible light can be more reliably separated, and the detection of invisible light is further improved. The safety of the image display device can be further enhanced.

  According to a fifth aspect of the present invention, there is provided a configuration in which stop means for stopping the operation of the semiconductor laser is provided by detection of invisible light by the invisible light detection means.

  According to the fifth aspect of the present invention, when the invisible light is detected to be more than the amount judged to be dangerous by providing the stop means for stopping the operation of the semiconductor laser by detecting the invisible light, the semiconductor Since the operation of the laser is stopped, the safety of the image display device can be ensured.

(Embodiment 1)
Hereinafter, the first embodiment will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of an image display device equipped with a laser light source device according to Embodiment 1 of the present invention. FIG. 2 is a schematic configuration diagram of the laser light source device according to Embodiment 1 of the present invention. First, the outline of the image display apparatus will be described with reference to FIG.

  The image display apparatus 100 is an image display apparatus that uses a laser beam as a light source and projects the enlarged image on a screen. The three light sources of the image display device 100 are a green laser light source device 1, a red laser light source device 2, and a blue laser light source device 3, and an image is displayed by the three color laser light source devices 1 to 3.

  The green laser light source device 1 mainly outputs green laser light 51 by incidentally converting infrared basic laser light which is invisible light into a half wavelength, and incidentally outputs infrared modulated laser light 55 as invisible light. (Details will be described later). The red laser light source device 2 outputs red laser light 52 and the blue laser light source device 3 outputs blue laser light 53.

  The collimator lenses 7 to 9 can change the color laser beams 51 to 53 output from the color laser light source devices 1 to 3 into parallel beams. The dichroic mirror 10a as an optical path separating unit and the dichroic mirror 11a as an optical path changing unit are configured by forming a film for transmitting or reflecting a laser beam having a predetermined wavelength on the surface. The diffusion plate 14 diffuses the passing laser beam, and the field lens 15 converts the diffused laser beam into a convergent laser. A PBS 16 (Polarized Beam Splitter) reflects each color laser beam 51 to 53 and transmits the laser beam reflected by the spatial light modulator 17. The spatial light modulator 17 is a reflective liquid crystal.

  The thermostat 20a as the invisible light detecting means is irradiated with an infrared modulated laser beam 55 which is invisible light separated by the dichroic mirror 10a. Thereby, the thermostat 20a absorbs the infrared modulation laser light 55 and is heated, so that the temperature of the thermostat 20a rises. The leakage of the infrared modulated laser beam 55 of the green laser light source device 1 can be detected by the temperature rise of the thermostat 20a.

  The respective color laser beams 51 to 53 from the respective color laser light source devices 1 to 3 are collimated by collimator lenses 7 to 9, respectively. The collimated color laser beams 51 to 53 are guided to the diffusion plate 14 by the dichroic mirrors 10a and 11a. Then, the light is reflected by the spatial light modulator 17 through the diffusion plate 14, the field lens 15, and the PBS 16 in this order, enlarged by the projection lens 18, and projected onto the screen 30.

  Next, how each color laser beam 51 to 53 from each color laser light source device 1 to 3 is guided in a predetermined direction will be specifically described.

  The green laser light source device 1 outputs green laser light 51 and leaks infrared modulation laser light 55 that is invisible light. Infrared modulated laser light 55 is collimated by collimator lens 7, passes through dichroic mirror 10a, and irradiates thermostat 20a (details will be described later). On the other hand, the green laser beam 51 is collimated by the collimator lens 7 and reflected by the dichroic mirror 10a in the direction of the dichroic mirror 11a, and the reflected green laser beam 51 is further reflected by the dichroic mirror 11a and thereby in the direction of the diffusion plate 14. Led.

  Similarly, the red laser light 52 output from the red laser light source device 2 is collimated by the collimator lens 8 and transmitted through the dichroic mirror 11a to be guided to the diffusion plate 14. Similarly, the blue laser light 53 output from the blue laser light source device 3 is collimated by the collimator lens 9 and transmitted through the dichroic mirror 10a. The transmitted blue laser light 53 is further reflected by the dichroic mirror 11a and diffused. Guided in the direction of the plate 14.

  That is, the dichroic mirror 10 a is coated with a green reflective film that reflects the green laser light 51, a blue transmissive film that transmits the blue laser light 53, and an infrared transmissive film that transmits the infrared modulated laser light 55. Therefore, the dichroic mirror 10a is an optical path separating unit in the present embodiment that separates the optical paths of the green laser beam 51 and the infrared modulated laser beam 55.

  The dichroic mirror 11 a is coated with a green reflection film that reflects the green laser light 51, a red transmission film that transmits the red laser light 52, and a blue reflection film that reflects the blue laser light 53. Therefore, the dichroic mirror 11a is an optical path changing means for guiding each color laser beam 51 to 53 in a predetermined direction. From the above, each color laser beam 51 to 53 other than the infrared modulation laser beam 55 which is invisible light in the configuration of FIG. 1 is guided toward the diffusion plate 14.

  The green laser beam 51, the red laser beam 52, and the blue laser beam 53 are diffused by the diffusion plate 14, the illuminance distribution is made uniform by the field lens 15, reflected by the PBS 16, and irradiated to the spatial light modulator 17. The spatial light modulator 17 is a reflective liquid crystal, and reflects so as to form an image based on the laser beams 51 to 53 guided in the above manner. The formed image is enlarged by the projection lens 18 and projected onto the screen 30. Here, the green laser light 51, the red laser light 52, and the blue laser light 53 are time-division controlled, and the respective color laser light source devices 1 to 3 are sequentially output. Accordingly, since the color laser beams 51 to 53 are sequentially projected from the projection lens 18, an image is formed on the screen 30 by the afterimages of the color laser beams 51 to 53.

  The red laser light source device 2 preferably outputs the red laser light 52 having a wavelength of 640 nm. However, as long as the red laser light source device 2 can be recognized as red, the red laser light source device 2 having a peak wavelength in the range of 610 to 750 nm may be used. Good. Similarly, the blue laser light source device 3 preferably outputs a blue laser beam 53 having a wavelength of 450 nm. However, if the blue laser light source device 3 can be recognized as blue, the peak wavelength is in the range of 435 to 480 nm and in a different wavelength region. Also good.

  Next, the green laser light source device 1 will be described with reference to FIG. The green laser light source device 1 outputs laser light having a wavelength twice that of a desired color to a half wavelength, and outputs the laser light as green laser light 51. This will be specifically described below.

  The cover 40 is a housing that houses each member. The cover 40 is preferably made of aluminum or copper having a high thermal conductivity, but may be formed by combining a metal having a high thermal conductivity and a resin. The semiconductor laser 41 arranged in contact with the cover 40 outputs an infrared basic laser beam 50 which is invisible light having a wavelength of 808 nm. The infrared basic laser beam 50 is changed into a parallel beam by a collimator lens 42 and is converted by a focusing lens 43. Focused on the laser medium 45. The laser medium 45 absorbs the infrared basic laser beam 50 to excite the invisible infrared modulation laser beam 55 having a wavelength of 1064 nm. The infrared modulation laser light 55 is converted into a half wavelength by an SHG (Second Harmonics Generation) element 48 which is a wavelength conversion element, and becomes green laser light 51 as visible light having a wavelength of 532 nm. The green laser light 51 is an opening portion of the cover 40. And is output to the outside of the green laser light source device 1. The glass cover 49 is formed with a film that does not transmit the infrared basic laser light 50 and the infrared modulated laser light 55 that are invisible light. This prevents the infrared basic laser beam 50 and the infrared modulated laser beam 55 from leaking to the outside.

Here, in the present embodiment, the laser medium 45 is obtained by doping 1% of Nd (neodymium) into a 2 mm thick inorganic optically active substance (crystal) made of Y (yttrium) VO ₄ (vanadate). More specifically, the laser medium 45 is doped with Nd ⁺³ which is a fluorescent element in Y of the base material YVO ₄ .

  Further, the end face 45a of the laser medium 45 is provided with a non-reflective coating (AR coating) for the infrared basic laser light 50 and a highly reflective coating (for the infrared modulation laser light 55 and the green laser light 51). HR coating). The end surface 48 a of the SHG element 48 is applied with a non-reflective coating to the green laser light 51 and a highly reflective coating with respect to the infrared modulation laser light 55.

  In other words, the infrared basic laser light 50 passes through the end face 45 a of the laser medium 45, and the infrared basic laser light 50 is excited by the laser medium 45 to the infrared modulated laser light 55. The infrared modulated laser beam 55 is repeatedly reflected by the end face 45a and the end face 48a of the SHG element 48 and resonates to become a laser beam with high light intensity, converted into a half wavelength by the SHG element 48, and external to the green laser light source device 1. Is output. That is, the end face 45a and the end face 48a constitute a resonator, and in this embodiment, the resonator length is 3 mm. If dust adheres to the end face 45a and the end face 48a, high reflectance cannot be maintained. For this reason, the light intensity of the infrared modulation laser light 55 is also lowered, and it is impossible to convert the infrared laser light 55 into the green laser light 51 having a high light intensity. Therefore, in order to prevent dust from entering the green laser light source device 1, the cover 40 covers these elements, and the opening from which the green laser light 51 is emitted is covered with a transparent glass cover 49.

  By configuring as described above, the green laser light source device 1 can output the green laser light 51 with high light intensity. However, since the SHG element 48 can only convert the infrared modulated laser light 55 into the green laser light 51 by about 40 to 50%, the infrared modulated laser light 55 is output from the SHG element 48 together with the green laser light 51. For this reason, the green laser light source device 1 is provided with a glass cover 49, and the glass cover 49 prevents leakage of the infrared modulated laser light 55 as invisible light.

  However, in the following cases, there is a possibility that the infrared modulated laser light 55 or the infrared basic laser light 50 as invisible light leaks to the outside of the green laser light source device 1. For example, when the laser medium 45 and the SHG element 48 are detached from the optical axis of the semiconductor laser 41 due to the fall of the image display device 100 or the like, there is a risk that the infrared basic laser light 50 leaks directly to the outside of the green laser light source device 1 at this time. There is. However, in this case, the infrared basic laser beam 50 passes through the dichroic mirror 10a and is absorbed by irradiating the thermostat 20a.

  Further, when only the SHG element 48 is deviated from the optical axis of the semiconductor laser 41, there is a risk that the infrared modulated laser beam 55 excited by the laser medium 45 at this time leaks directly to the outside of the green laser light source device 1. However, in this case, the infrared modulated laser beam 55 is absorbed by being transmitted through the dichroic mirror 10a and irradiating the thermostat 20a.

  Further, the infrared basic laser beam 50 and the infrared modulation laser beam 55 are slightly shifted from the designed optical axes, so that the conversion efficiency of the SHG element 48 is deteriorated. Accordingly, it is conceivable that the infrared basic laser light 50 or the infrared modulated laser light 55 leaks, which cannot be prevented by the glass cover 49 alone. However, even in this case, both the infrared basic laser beam 50 and the infrared modulated laser beam 55 pass through the dichroic mirror 10a and are absorbed by irradiating the thermostat 20a.

  Therefore, the dichroic mirror 10 a can transmit both the infrared basic laser beam 50 and the infrared modulated laser beam 55. The dichroic mirror 10a is coated with an infrared transmission film, and can transmit light when the wavelength of incident light is in the infrared light region. In other words, the laser beam that allows the dichroic mirror 10a to separate the optical path from the green laser beam 51 is not limited to the infrared basic laser beam 50 having a wavelength of 808 nm and the infrared modulated laser beam 55 having a wavelength of 1064 nm.

  The thermostat 20 a is electrically connected to the power supply unit of the semiconductor laser 41, and also serves as a non-visible light detection unit and a stopping unit that stops the operation of the semiconductor laser 41.

  With the above configuration, the dichroic mirror 10 a separates the optical path between the green laser light 51 and the infrared modulated laser light 55 output from the green laser light source device 1 outside the green laser light source device 1, and the infrared modulated laser light 55. Is absorbed by the thermostat 20a.

  For this reason, since the infrared modulation laser light 55 is not reflected and absorbed by the cover 40 or the like, the green laser light source device 1 is not heated. Therefore, since the semiconductor laser 41 built in the green laser light source device 1 is not similarly heated and does not reach a high temperature, the emission efficiency of the semiconductor laser 41 can be prevented from being lowered. Therefore, even if the semiconductor laser 41 operates continuously for a long time, the emission efficiency is prevented from decreasing. Therefore, the life of the semiconductor laser 41 can be extended. Furthermore, since the semiconductor laser 41 is disposed in contact with the cover 40, the heat of the semiconductor laser 41 can be radiated to the outside through the cover 40.

  Further, the dichroic mirror 10a and the thermostat 20a are arranged on the straight line in the output direction of the green laser light source device 1 in FIG. For this reason, even if the dichroic mirror 10a is removed, the infrared modulated laser beam 55 is reliably irradiated to the thermostat 20a. Alternatively, even if the incident position of the infrared modulated laser beam 55 changes due to the displacement of the dichroic mirror 10a, or the incident angle of the infrared modulated laser beam 55 changes due to the tilt of the dichroic mirror 10a, the infrared modulated laser beam. 55 is irradiated to the thermostat 20a. That is, since the infrared modulated laser beam 55 is transmitted without being reflected by the dichroic mirror 10a, the thermostat 20a is irradiated. Therefore, even if the dichroic mirror 10a is displaced, tilted, or detached, the infrared modulated laser light 55 does not travel to the optical paths of the respective color laser lights 51 to 53. Therefore, it is possible to prevent the infrared modulated laser light 55 and the infrared basic laser light 50 from leaking outside the image display apparatus 100.

  Further, the thermostat 20a in the present embodiment is also a non-visible light detecting unit, and the thermostat 20a also has a function as a stopping unit by being electrically connected to the power supply unit of the semiconductor laser 41. As described above, as the invisible light detection means, the leakage of the infrared modulated laser beam 55 is detected by the temperature rise of the thermostat 20a. That is, when the infrared modulation laser beam 55 or the infrared basic laser beam 50 of a predetermined amount or more leaks and the thermostat 20a is heated too much, the thermostat switch is switched from on to off, and at the same time, power is supplied to the semiconductor laser 41. Can be cut off. Therefore, the safety of the image display apparatus 100 is further improved.

  Here, the thermostat is set so as to operate when the infrared modulated laser beam 55 or the infrared basic laser beam 50 is output at 100 mW or more.

  Further, for example, by using a photodiode instead of a thermostat, when the infrared modulation laser light 55 is irradiated more than a certain output, it is detected, and a lamp notifying the outside of the image display device 100 is flashed. With this configuration, an abnormality of the image display apparatus 100 can be communicated to the user. As a result, the user can know the failure of the image display device 100 and can take appropriate measures such as repairing, so that the safety of the image display device 100 is further improved.

  The thermostat 20a has at least the portion irradiated from the laser light black so that the laser light can be easily absorbed, and the infrared basic laser light 50 and the infrared modulated laser light 55 are more reliably leaked. The thermostat 20a can be operated. Further, the thermostat 20a is preferably as small as possible and has a low heat capacity. In that case, the thermostat 20a is heated at the time of abnormality, but the time from the occurrence of the abnormality to the operation can be made earlier. In addition, you may substitute with a fuse, a thermistor, etc. not only the thermostat 20a. It is only necessary that the power supply of the green laser light source device 1 or the semiconductor laser 41 can be cut off at the time of abnormality.

  In the present embodiment, the dichroic mirrors 10a and 11a are used. However, the present invention is not limited to this, and other mirrors or prisms may be used.

(Embodiment 2)
The second embodiment will be described below with reference to FIG. FIG. 3 is a schematic configuration diagram of an image display device on which the laser light source device according to Embodiment 2 of the present invention is mounted. Here, members having the same configurations and functions as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the present embodiment, not only the thermostat 20a but also the thermostat 20b is provided in the image display device 100, so that the safety is further improved as compared with the first embodiment. The thermostat 20b has the same function as the thermostat 20a and is electrically connected to the power supply unit of the semiconductor laser 41. 55a and 55b are both infrared modulation laser light 55 as invisible light, and the infrared modulation laser light 55a is the infrared modulation laser light 55 transmitted through the dichroic mirror 10b, and the infrared modulation laser light 55b. Is the infrared modulated laser beam 55 reflected from the dichroic mirror 10b.

  Hereinafter, the optical paths of the respective color laser beams 51 to 53 and the infrared modulated laser beam 55 output from the respective color laser light source devices 1 to 3 in the present embodiment will be described.

  When the green laser light 51 is output from the green laser light source device 1, it is collimated by the collimator lens 7 and reflected by the dichroic mirror 10b as the optical path separating means in the direction of the dichroic mirror 11b as the optical path separating means. By being reflected in the direction of the diffusion plate 14, the light is guided in a predetermined direction.

  When the red laser light 52 is output by the red laser light source device 2, it is collimated by the collimator lens 8 and is transmitted to the dichroic mirror 11 b and guided to the diffusion plate 14.

  When the blue laser light 53 is output by the blue laser light source device 3, it is collimated by the collimator lens 9, passes through the dichroic mirror 10b, and is reflected by the dichroic mirror 11b in the direction of the diffuser plate 14, thereby causing a predetermined direction. Led.

  Further, accompanying the output of the green laser light 51 from the green laser light source device 1, the infrared modulated laser light 55 that is incidentally leaking invisible light is collimated by the collimator lens 7 and passes through the dichroic mirror 10b. Thereby, the infrared modulation laser beam 55a irradiates the thermostat 20a. On the other hand, the infrared modulated laser beam 55b that cannot be transmitted by the dichroic mirror 10b but is reflected by mistake passes through the dichroic mirror 11b. Thereby, the infrared modulation laser beam 55b irradiates the thermostat 20b.

  Therefore, the dichroic mirror 10b is coated with a green reflective film that reflects the green laser light 51, a blue transmissive film that transmits the blue laser light 53, and an infrared transmissive film that transmits the infrared modulated laser light 55.

  Further, the dichroic mirror 11b is a green reflective film that reflects green laser light, a red transmissive film that transmits red laser light 52, a blue reflective film that reflects blue laser light 53, and red that transmits infrared modulated laser light 55. An outer permeable membrane is applied. Therefore, both the dichroic mirrors 10b and 11b are optical path separation means in the present embodiment. For this reason, in the configuration of FIG. 3, the respective color laser beams 51 to 53 other than the infrared modulation laser beam 55 are guided toward the diffusion plate 14.

  With the above configuration, the dichroic mirrors 10b and 11b separate the optical paths of the green laser light 51 and the infrared modulated laser light 55 output from the green laser light source device 1 by the outside of the green laser light source device 1 and are invisible light. The infrared modulated laser beam 55 is absorbed by the thermostats 20a and 20b.

  For this reason, since the infrared modulation laser light 55 is not reflected and absorbed by the cover 40 or the like, the green laser light source device 1 is not heated. Therefore, since the semiconductor laser 41 built in the green laser light source device 1 is not similarly heated and does not reach a high temperature, the emission efficiency of the semiconductor laser 41 can be prevented from being lowered. Therefore, even if the semiconductor laser 41 operates continuously for a long time, the emission efficiency is prevented from decreasing. Therefore, the life of the semiconductor laser 41 can be extended.

  Furthermore, the dichroic mirror 10b and the thermostat 20a are arranged substantially linearly in the output direction of the green laser light source device 1 in FIG. For this reason, even if the dichroic mirror 10b is displaced, tilted, or detached, the infrared modulated laser light 55 can reliably irradiate the thermostat 20a. Accordingly, it is possible to prevent the infrared modulated laser light 55 from leaking outside the image display device 100.

  That is, this embodiment obtains the same effect as that of the first embodiment.

  Further, even if a part of the infrared modulation laser beam 55 is reflected without being transmitted through the dichroic mirror 10b, that is, even when the infrared modulation laser beam 55b exists, the infrared modulation laser beam 55b is transmitted by the dichroic mirror 11b. Since the optical paths are separated from the respective color laser beams 51 to 53, the infrared modulated laser beam 55b can be prevented from leaking outside the image display device 100. Therefore, the dichroic mirrors 10 b and 11 b are both optical path separating means for separating the optical paths of the respective color laser beams 51 to 53 and the infrared modulated laser beam 55. Since the thermostats 20a and 20b are provided corresponding to the dichroic mirrors 10b and 11b, the infrared modulated laser light 55 that continues to be reflected without being irradiated anywhere in the image display apparatus 100 can be further reduced. Therefore, the image display apparatus 100 according to the present embodiment is less likely to leak the infrared modulation laser light 55 that is more invisible, and thus high safety can be ensured.

  Furthermore, even if the infrared basic laser beam 50 or the infrared modulated laser beam 55 leaks more than necessary, the thermostat 20a or 20b senses it and shuts off the green laser light source device 1.

  Similarly, in the present embodiment, the dichroic mirrors 10b and 11b are not limited to the infrared modulated laser light 55 or the infrared basic laser light 50 but are infrared light.

(Embodiment 3)
Hereinafter, Embodiment 3 will be described with reference to FIG. FIG. 4 is a schematic configuration diagram of an image display device on which the laser light source device according to Embodiment 3 of the present invention is mounted. Here, members having the same configurations and functions as those of the first and second embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  An optical path of each color laser beam 51 to 53 output from each color laser light source device 1 to 3 in this embodiment and infrared modulation laser beam 55 which is invisible light will be described.

  When the green laser light 51 is output from the green laser light source device 1, it is collimated by the collimator lens 7, reflected by the dichroic mirror 10c as the optical path changing means in the direction of the dichroic mirror 11c, and the dichroic mirror 11c as the optical path separating means. By being reflected in the direction of the diffusion plate 14, the light is guided in a predetermined direction.

  When the red laser light 52 is output by the red laser light source device 2, it is collimated by the collimator lens 8 and is transmitted to the dichroic mirror 11 c and guided to the diffusion plate 14.

  When the blue laser light 53 is output from the blue laser light source device 3, it is collimated by the collimator lens 9, passes through the dichroic mirror 10 c, and is reflected by the dichroic mirror 11 c toward the diffusion plate 14. Led.

  Further, accompanying the output of the green laser light 51 from the green laser light source device 1, the infrared modulation laser light 55 that is incidentally leaking invisible light is collimated by the collimator lens 7 and is reflected by the dichroic mirror 10c to the dichroic mirror 11c. Reflected in the direction and transmitted through the dichroic mirror 11c. Thereby, the infrared modulation laser beam 55 is separated from the optical paths of the respective color laser beams 51 to 53 and irradiates the thermostat 20b.

  That is, the dichroic mirror 10 c is coated with a green reflective film that reflects the green laser light 51, a blue transmission film that transmits the blue laser light 53, and an infrared reflective film that reflects the infrared modulated laser light 55.

  The dichroic mirror 11c receives a green reflective film that reflects green laser light, a red transmissive film that transmits red laser light 52, a blue reflective film that reflects blue laser light 53, and infrared modulated laser light 55 as invisible light. An infrared transmission film that allows transmission is applied. Therefore, the dichroic mirror 11c is an optical path separating unit in the present embodiment. For this reason, in the configuration of FIG. 4, each color laser beam 51 to 53 other than the infrared modulation laser beam 55 is guided toward the diffusion plate 14. Similarly, in the present embodiment, not only the infrared modulated laser beam 55 or the infrared basic laser beam 50 but also infrared light is transmitted through the dichroic mirror 11c.

  With the above configuration, the dichroic mirror 11c separates the optical path of the green laser light 51 and the infrared modulated laser light 55 output from the green laser light source device 1 by the outside of the green laser light source device 1 and performs infrared modulation of invisible light. The laser beam 55 is absorbed by the thermostat 20b.

  Therefore, it is possible to prevent the light emission efficiency of the semiconductor laser 41 from being lowered. Even if the dichroic mirror 11c is displaced, tilted, or detached, the infrared modulated laser light 55 can irradiate the thermostat 20b and does not travel to the optical path of each color laser light 51-53. Furthermore, even if the infrared modulation laser light 55 leaks excessively, the operation of the semiconductor laser 41 can be stopped by the characteristics of the thermostat 20b.

  Thereby, the safety of the image display apparatus 100 can be ensured.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to prevent a decrease in light emission efficiency of a semiconductor laser, and it can be used for a highly safe image display device that does not leak invisible light to the outside.

DESCRIPTION OF SYMBOLS 1 Green laser light source device 2 Red laser light source device 3 Blue laser light source device 7, 8, 9 Collimator lens 10a, 10b, 10c, 11a, 11b, 11c Dichroic mirror 14 Diffusion plate 15 Field lens 16 PBS
17 Spatial Light Modulating Element 18 Projection Lens 20a, 20b Thermostat 30 Screen 40 Cover 41 Semiconductor Laser 42 Collimating Lens 43 Focusing Lens 45 Laser Medium 45a End Face 48 SHG Element 48a End Face 49 Glass Cover 50 Infrared Basic Laser Light 51 Green Laser Light 52 Red Laser beam 53 Blue laser beam 55 Infrared modulated laser beam 100 Image display device

Claims (5)

A laser light source device comprising: a semiconductor laser that emits invisible light; and a wavelength converter that converts the invisible light emitted by the semiconductor laser into visible light, and emits visible light converted by the wavelength converter to the outside. When,
An image display device comprising optical path separating means for separating optical paths of visible light and invisible light emitted from the laser light source device,
An invisible light detecting means for detecting invisible light separated by an optical path separating means and the at least one optical path separating means are provided outside the laser light source device, and immediately before being separated by the at least one optical path separating means. An invisible light detecting means is provided on an extended line of the visible light optical path. 2. The image display device according to claim 1, wherein the laser light source device, the optical path separating unit, and the invisible light detecting unit are arranged in a substantially linear shape. An optical path changing means for changing the optical paths of visible light and invisible light emitted from the laser light source device is provided, and the optical path separating means is provided on the optical path of visible light whose optical path is changed by the optical path changing means. 2. The image display device according to claim 1, wherein the invisible light detecting means is provided on an extension line of the optical path of visible light immediately before being separated by the separating means. 2. The image display device according to claim 1, wherein a plurality of the optical path separating means are provided, and the invisible light detecting means is provided on an extension of the optical path of visible light immediately before being separated by each of the optical path separating means. . The image display apparatus according to claim 1, further comprising a stopping unit that stops the operation of the semiconductor laser by detecting the invisible light by the invisible light detecting unit.

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