JP4924767B1 - LASER LIGHT SOURCE DEVICE AND IMAGE DISPLAY DEVICE MOUNTING THE SAME - Google Patents

Abstract

When the device is removed from the device to be originally used, the output is reduced at the time of a single operation. On the other hand, when the device is incorporated in the device to be originally used, the green laser light is normally emitted. Provided are a laser light source device configured as described above, and an image display device that is equipped with the laser light source device and can emit green laser light.
A semiconductor laser 31 that outputs an excitation laser beam, a solid-state laser element 34 that is excited by the excitation laser beam and outputs a basic laser beam, and a base 38 that supports the semiconductor laser and the solid-state laser element 34. The solid-state laser element 34 has a substantially rectangular parallelepiped shape, and at least two of the four surfaces excluding the incident surface of the excitation laser beam from the semiconductor laser 31 and the emission surface of the basic laser beam are adjacent to each other. Each of the two surfaces is in contact with the base 38 with a contact area smaller than its surface area.
[Selection] Figure 14

Description

  The present invention relates to a laser light source device using a semiconductor laser, and more particularly to a laser light source device used for a light source of an image display device.

  In recent years, a technique using a semiconductor laser as a light source of an image display device has attracted attention. This semiconductor laser has better color reproducibility, instantaneous lighting, longer life, and higher power consumption compared to mercury lamps that have been widely used in image display devices. It has various advantages, such as being able to be made and being easy to miniaturize.

  In the laser light source device used for such an image display device, since there is no high-power semiconductor laser that directly outputs green laser light, the pumping laser light is output from the semiconductor laser, and this pumping laser light is used. A technique is known in which a solid-state laser element is excited to output infrared laser light, and the wavelength of the infrared laser light is converted by a wavelength conversion element to output green laser light (for example, Patent Document 1). reference).

JP 2008-16833 A

  In the image display device configured as described above, in order to prevent the output light from the laser light source device including the green laser light source device from inadvertently hitting the user's eyes, the output power is limited and the user Disassembly of the device by is prohibited.

  However, the user may be interested in the green laser light source device attached to the image display device and may attempt to use it alone for another application such as a pointer. This situation can occur particularly when a part other than the green laser light source device of the image display device fails and cannot be used, or when the user wants to know the operation of the green laser light source. Of course, it is not assumed that the green laser light source device is used alone for such an application that is not an original image display, which may cause an unexpected situation, which is not preferable.

  Next, as described above, infrared laser light is output inside the green laser light source device by such wavelength conversion. If the user removes only the green laser light source device from the image display device and the user tries to cause the green laser light source device to emit light alone, a part of the members constituting the green laser light source device is accidentally dropped. there's a possibility that. If this happens, the infrared laser light leaks out of the green laser light source device, and even if it hits the user's eyes, the user cannot know it. It ’s very dangerous.

  The present invention has been devised to solve such problems of the prior art. The main object of the present invention is to provide a green laser light source device even if the laser light source device by wavelength conversion is removed. The purpose is to reduce the output during single operation. Next, on the other hand, when it is incorporated in the image display device, a laser light source device configured to emit green laser light and the laser light source device mounted thereon to emit green laser light. An object of the present invention is to provide an image display device that can perform the above-described operation.

The laser light source device of the present invention includes a semiconductor laser that outputs excitation laser light, a solid-state laser element that is excited by the excitation laser light and outputs basic laser light, and is disposed on the semiconductor laser side from the semiconductor laser. The FAC lens for converging the excitation laser beam in the emitter thickness direction, and also arranged on the solid-state laser element side to focus the excitation laser light from the semiconductor laser on the solid-state laser element, from the semiconductor laser And a base that supports the semiconductor laser , the FAC lens, the rod lens, and the solid-state laser element, and the semiconductor laser has an emitter width direction. A high-power semiconductor laser that is larger than the thickness direction of the emitter, and the pumping laser from the semiconductor laser. The spread angle of the light is smaller in the emitter width direction than the emitter thickness direction, and the base excludes the incident surface of the excitation laser light from the semiconductor laser and the emission surface of the basic laser light that the solid-state laser element has Of the four surfaces, a first convex portion formed of three locations facing the first surface parallel to the emitter width direction, and adjacent to the first surface of the solid-state laser element, the emitter thickness direction A second convex portion having two locations provided opposite to a second surface parallel to the second surface, and a third convex portion opposite to the second surface of the solid-state laser element and adjacent to the first surface. A third convex portion provided opposite to the surface of the first projection, wherein the mounting surface of the FAC lens and the rod lens on the base is on the same emitter width direction side as the second convex portion. And in parallel with the optical axis emitted from the semiconductor laser, One said semiconductor optical axis the FAC lens emitted from a laser, is disposed so as to pass through the center of each part of the rod lens and the solid-state laser device, the solid-state laser element is in contact supported by the first convex portion The adhesive is dripped into a space that is in contact with the second convex portion, surrounded by the second convex portion and the second surface, and further, the third convex portion and the third surface It is fixed by dropping an adhesive into a space between them, and has a substantially rectangular parallelepiped shape that is longer in the emitter width direction than in the emitter thickness direction of the semiconductor laser .

According to the present invention, when the laser light source device is removed from the device to be originally used, that is, the image display device, for a purpose different from the original, the laser light source device can operate only at a low output. On the other hand, when this laser light source device is incorporated in a device to be originally used, that is, in an image display device, the basic laser light that is the basis of the green laser light is normally emitted. As a result, even if the green laser light source device is removed from the main body of the image display device and a single operation is attempted without impairing the operation as the image display device, the output of the laser light affects the human body. Its safety is ensured because it is so low. Further, the solid laser element is suppressed from rotating around the height direction axis and the width direction axis. In particular, since the influence of the unbalance of the shrinkage force generated at the time of curing of the adhesive is reduced, such rotation is further suppressed. In addition, when the semiconductor laser is focused on the solid-state laser element, the beam diameter is reduced, the NA is reduced, and the beam becomes longer in the emitter direction, so that the emitter width direction is longer than the emitter thickness direction of the semiconductor laser. Even if a solid-state laser element having a substantially rectangular parallelepiped shape has a mounting error and the output light from the semiconductor laser deviates from the center of the laser light incident surface from the semiconductor laser of the solid-state laser element, The influence on the excitation by the element can be reduced. Therefore, when this laser light source device is to be used originally, that is, in a state where it is incorporated in an image display device, even if the solid laser element and the fixed surface of the base are partially contacted, the entire surface contact in pulse drive It has the same operating characteristics as the case.

The perspective view which shows the example which incorporated the image display apparatus 1 by this invention in the portable information processing apparatus 151 The schematic block diagram of the optical engine unit 156 of the image display apparatus 1 by this invention. The schematic diagram which shows the condition of the laser beam in the green laser light source apparatus 2 Internal perspective view of green laser light source device 2 Sectional view of green laser light source device 2 A perspective view of the wavelength conversion element 35 The figure which shows the change condition of wavelength conversion efficiency (eta) according to inclination-angle (theta) of the wavelength conversion element 35 with respect to an optical axis direction. Functional block diagram of the image display device 1 shown in FIG. The relationship between the lighting sequence during the normal operation in which white display is performed by the first normal lighting sequence for lighting the green laser light source device 2, the red laser light source device 3, and the blue laser light source device 4 and the operation of the spatial light modulator 25. Illustration The figure which shows the output immediately after starting lighting of the green laser light source apparatus 2 by a 1st normal lighting sequence. In the first normal lighting sequence, the green laser light source device 2, the red laser light source device 3, and the blue laser light source device 4 are turned on to perform blue display, and the first warm-up for speeding up the start of the green laser light source device 2 The figure which shows the relationship between a sequence and operation | movement of the spatial light modulation element 25 The figure which shows the output at the time of green laser light source apparatus starting by a 1st warm-up sequence The figure which shows the example of the other normal lighting sequence which lights the green laser light source device 2, the red laser light source device 3, and the blue laser light source device 4 The perspective view which showed centering on the solid laser element 34 among the components which comprise the green laser light source device 2, and the base 38 which supports it. Enlarged perspective view of solid-state laser element 34 and its peripheral part The figure which looked at the green laser light source device 2 from the upper surface The figure which shows the operating characteristic of the green laser light source apparatus 2 of this Embodiment

A first invention made to solve the above-described problems is a semiconductor laser that outputs excitation laser light, a solid-state laser element that is excited by the excitation laser light and outputs basic laser light, and excitation from the semiconductor laser. In order to focus the laser beam for the solid laser element, the FAC lens is arranged on the semiconductor laser side and converges the laser beam for excitation from the semiconductor laser in the emitter thickness direction, and the laser beam for excitation from the semiconductor laser is also solid. In order to focus on the laser element, a rod lens arranged on the solid-state laser element side for converging excitation laser light from the semiconductor laser in the emitter width direction, and a semiconductor laser , an FAC lens, a rod lens, and a solid-state laser element are supported. comprising a base, a semiconductor laser is Ah high-power semiconductor lasers greater emitter width direction as compared to the emitter thickness direction The divergence angle of the excitation laser light from the semiconductor laser is smaller in the emitter width direction than the emitter thickness direction, and the base is the incident surface of the excitation laser light from the semiconductor laser of the solid-state laser element and the emission of the basic laser light Of the four surfaces excluding the surface, a first convex portion comprising three locations provided to face the first surface parallel to the emitter width direction, and the emitter thickness direction adjacent to the first surface of the solid-state laser element And a second surface that is opposite to the second surface of the solid-state laser element and is adjacent to the first surface. A third convex portion provided opposite to the first convex portion, wherein the mounting surface of the FAC lens and the rod lens is on the same emitter width direction side as the second convex portion and from the semiconductor laser. Output from the semiconductor laser in parallel with the output optical axis Axis is disposed so as to pass through the center of each part of the FAC lens, a rod lens and the solid state laser element, solid-state laser element is in contact with the support in the first protrusion abuts a second protrusion, the second The adhesive is dropped into the space surrounded by the convex portion and the second surface, and further, the adhesive is dropped into the space between the third convex portion and the third surface, so that the semiconductor is fixed. The configuration has a substantially rectangular parallelepiped shape that is longer in the emitter width direction than in the laser emitter thickness direction .

According to this, when removed from a device that should be originally used for a different purpose, it should only operate at a low power while it is in a state that is built into the device that is intended to be used. The basic laser beam that is the basis of the green laser beam is emitted normally. In addition, even if a mounting error of the solid-state laser element occurs and the output light from the semiconductor laser deviates from the center of the laser light incident surface from the semiconductor laser of the solid-state laser element, it gives to the excitation by the solid-state laser element. The influence can be reduced. Therefore, when this laser light source device is to be used originally, that is, in a state where it is incorporated in an image display device, even if the solid laser element and the fixed surface of the base are partially contacted, the entire surface contact in pulse drive It has the same operating characteristics as the case.

Further, the second invention is the wavelength conversion element according to the first invention, wherein the wavelength conversion element converts the wavelength of the basic laser light output from the solid-state laser element to generate and outputs a half-wavelength laser light, and is converted by the wavelength conversion element. A mirror that reflects the fundamental laser light that has not been reflected and transmits the half-wavelength laser light, and the wavelength conversion element can be translated in the depth direction of the domain-inverted region, and in the optical axis direction of the fundamental laser light. is held by the tiltable holder for the holder and the mirror is supported by the base, the solid-state laser element has a substantially rectangular parallelepiped shape longer emitter width direction than the emitter thickness direction of the semiconductor laser, an emitter The width direction is set to be the depth direction of the polarization inversion region of the wavelength conversion element .

According to this, the position of the wavelength conversion element with respect to the optical axis of the laser beam is adjusted so that the output of the laser beam becomes maximum with respect to the laser beam that is long in the emitter width direction, and the wavelength conversion element is aligned in the optical axis direction. Since the wavelength conversion efficiency is increased by inclining with respect to, even if the solid-state laser element and the fixed surface of the base are in partial contact, the operation characteristics are comparable to those in the case of full contact in pulse driving.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing an example in which an image display device 1 according to the present invention is built in a portable information processing device 151. In the main body 152 of the portable information processing apparatus 151, a storage space, in which a peripheral device such as an optical disk device is replaceably stored, a so-called drive bay is formed on the back side of the keyboard 153, and an image is displayed on the drive bay. The apparatus 1 is attached so that it can be moved up and down.

  The image display device 1 includes a container 154 and a movable body 155 provided so as to be able to be taken in and out of the container 154. The movable body 155 includes an optical engine unit 156 in which optical components for projecting laser light onto the screen S are accommodated, and a control unit 157 in which a substrate for controlling the optical components in the optical engine unit 156 is accommodated. The optical engine unit 156 is supported by the control unit 157 so as to be rotatable in the vertical direction.

  In the image display device 1, the movable body 155 is stored in the housing body 154 when not in use, and the movable body 155 is pulled out from the housing body 154 when in use, and the optical engine unit 156 is rotated to remove the optical body from the optical engine unit 156. The laser light can be appropriately projected onto the screen S by adjusting the projection angle of the laser light.

  FIG. 2 is a schematic configuration diagram of the optical engine unit 156 of the image display device 1 according to the present invention. The optical engine unit 156 projects and displays a required image on a screen, and outputs a green laser light source device 2 that outputs green laser light, a red laser light source device 3 that outputs red laser light, and a blue laser light. The blue laser light source device 4 to output, the liquid crystal reflection type spatial light modulator 5 that modulates the laser light from each laser light source device 2 to 4 according to the video signal, and the laser from each laser light source device 2 to 4 A polarization beam splitter 6 that reflects light to irradiate the spatial light modulator 5 and transmits the modulated laser light emitted from the spatial light modulator 5, and polarizes the laser light emitted from each of the laser light source devices 2 to 4. A relay optical system 7 that leads to the beam splitter 6 and a projection optical system 8 that projects the modulated laser light transmitted through the polarization beam splitter 6 onto a screen are provided.

  The optical engine unit 156 displays a color image by a so-called field sequential method. Laser beams of each color are sequentially output from the laser light source devices 2 to 4 in a time-sharing manner, and an image by the laser beam of each color is visually displayed. It is recognized as a color image by the afterimage effect.

  The relay optical system 7 includes collimator lenses 11 to 13 that convert the laser beams of the respective colors emitted from the laser light source devices 2 to 4 into parallel beams, and the laser beams of the respective colors that have passed through the collimator lenses 11 to 13 in a predetermined direction. First and second dichroic mirrors 14 and 15, a diffusion plate 16 for diffusing the laser light guided by the dichroic mirrors 14 and 15, and a field lens for converting the laser light that has passed through the diffusion plate 16 into a convergent laser 17.

  Assuming that the side from which the laser light is emitted from the projection optical system 8 toward the screen S is the front side, the blue laser light is emitted backward from the blue laser light source device 4 and is green with respect to the optical axis of the blue laser light. The green laser beam and the red laser beam are emitted from the green laser light source device 2 and the red laser light source device 3 so that the optical axis of the laser beam and the optical axis of the red laser beam are orthogonal to each other. , And green laser light are guided to the same optical path by the two dichroic mirrors 14 and 15. That is, the blue laser light and the green laser light are guided to the same optical path by the first dichroic mirror 14, and the blue laser light, the green laser light, and the red laser light are guided to the same optical path by the second dichroic mirror 15.

  The first and second dichroic mirrors 14 and 15 are formed with a film for transmitting and reflecting laser light having a predetermined wavelength on the surface, and the first dichroic mirror 14 transmits blue laser light. And reflects the green laser light. The second dichroic mirror 15 transmits red laser light and reflects blue laser light and green laser light.

  Each of these optical members is supported by the casing 21. The housing 21 functions as a radiator that dissipates heat generated by the laser light source devices 2 to 4 and is formed of a material having high thermal conductivity such as aluminum or copper.

  The green laser light source device 2 is attached to an attachment portion 22 formed in the housing 21 in a state of protruding toward the side. The mounting portion 22 is provided in a state of projecting in a direction perpendicular to the side wall portion 24 from a corner portion where the front wall portion 23 and the side wall portion 24 located respectively in front and side of the accommodation space of the relay optical system 7 intersect. ing. The red laser light source device 3 is attached to the outer surface side of the side wall portion 24 while being held by the holder 25. The blue laser light source device 4 is attached to the outer surface side of the front wall portion 23 while being held by the holder 26.

  The red laser light source device 3 and the blue laser light source device 4 are configured by a so-called CAN package, and the optical axis is positioned on the central axis of the can-shaped exterior portion with the laser chip that outputs the laser light supported by the stem. The laser beam is emitted from a glass window provided in the opening of the exterior part. The red laser light source device 3 and the blue laser light source device 4 are fixed to the holders 25 and 26 by, for example, press-fitting into mounting holes 27 and 28 provided in the holders 25 and 26. The heat generated by the laser chips of the blue laser light source device 4 and the red laser light source device 3 is transmitted to the housing 21 through the holders 25 and 26 to be dissipated, and each of the holders 25 and 26 has a thermal conductivity such as aluminum or copper. It is made of a high material.

  The green laser light source device 2 includes a semiconductor laser 31 that outputs excitation laser light, a FAC (Fast-Axis Collimator) lens 32 that is a condensing lens that collects the excitation laser light output from the semiconductor laser 31, and a rod. A lens 33, a solid-state laser element 34 that outputs a basic laser beam (infrared laser beam) when excited by an excitation laser beam, and outputs a half-wavelength laser beam (green laser beam) by converting the wavelength of the basic laser beam Wavelength conversion element (optical element) 35, concave mirror 36 that forms a resonator together with solid-state laser element 34, glass cover 37 that prevents leakage of excitation laser light and fundamental wavelength laser light, and a base that supports each part The base 38 and the cover body 39 which covers each part are provided.

  The green laser light source device 2 is fixed by attaching a base 38 to the mounting portion 22 of the housing 21, and a required width (for example, 0.5 mm) between the green laser light source device 2 and the side wall portion 24 of the housing 21. The following gaps are formed. This makes it difficult for the heat of the green laser light source device 2 to be transmitted to the red laser light source device 3, suppresses the temperature rise of the red laser light source device 3, and allows the red laser light source device 3 with poor temperature characteristics to operate stably. Can do. Further, in order to secure a required optical axis adjustment allowance (for example, about 0.3 mm) of the red laser light source device 3, a required width (for example, 0.3 mm or more) is provided between the green laser light source device 2 and the red laser light source device 3. ) Is provided.

  FIG. 3 is a schematic diagram illustrating a state of laser light in the green laser light source device 2. The laser chip 41 of the semiconductor laser 31 outputs excitation laser light having a wavelength of 808 nm. The FAC lens 32 reduces the spread of the first axis of the laser light (the direction orthogonal to the optical axis direction and along the drawing sheet). The rod lens 33 reduces the spread of the slow axis of laser light (in the direction orthogonal to the drawing sheet).

  The solid-state laser element 34 is a so-called solid-state laser crystal, and is excited by excitation laser light having a wavelength of 808 nm that has passed through the rod lens 33 to output a fundamental wavelength laser light (infrared laser light) having a wavelength of 1064 nm. This solid-state laser element 34 is obtained by doping an inorganic optically active substance (crystal) made of Y (yttrium) VO4 (vanadate) with Nd (neodymium), and more specifically, Y of the base material YVO4. It is doped by substitution with Nd + 3 which is an element that emits fluorescence.

  On the side of the solid-state laser element 34 facing the rod lens 33, a film having a function of preventing reflection of excitation laser light having a wavelength of 808 nm and high reflection of half-wavelength laser light having a wavelength of 1064 nm and a wavelength of 532 nm. 42 is formed. On the side of the solid-state laser element 34 facing the wavelength conversion element 35, a film 43 having an antireflection function for the fundamental wavelength laser light having a wavelength of 1064 nm and the half wavelength laser light having a wavelength of 532 nm is formed.

  The wavelength conversion element 35 is a so-called SHG (Second Harmonics Generation) element, which converts the wavelength of a fundamental wavelength laser beam (infrared laser beam) having a wavelength of 1064 nm output from the solid-state laser element 34 to a half-wavelength laser having a wavelength of 532 nm. Light (green laser light) is generated.

  On the side of the wavelength conversion element 35 facing the solid-state laser element 34, a film 44 having functions of preventing reflection with respect to the fundamental wavelength laser beam with a wavelength of 1064 nm and highly reflecting with respect to the half wavelength laser beam with a wavelength of 532 nm is formed. On the side facing the concave mirror 36 in the wavelength conversion element 35, a film 45 having an antireflection function for the fundamental wavelength laser beam having a wavelength of 1064 nm and the half wavelength laser beam having a wavelength of 532 nm is formed.

  The concave mirror 36 has a concave surface on the side facing the wavelength conversion element 35, and this concave surface has a function of high reflection with respect to a fundamental wavelength laser beam with a wavelength of 1064 nm and antireflection with respect to a half wavelength laser beam with a wavelength of 532 nm. A film 46 is formed. Thereby, the fundamental wavelength laser beam having a wavelength of 1064 nm resonates and is amplified between the film 42 of the solid-state laser element 34 and the film 46 of the concave mirror 36.

  In the wavelength conversion element 35, a part of the fundamental wavelength laser light having a wavelength of 1064 nm incident from the solid-state laser element 34 is converted into a half-wavelength laser light having a wavelength of 532 nm, and the fundamental wavelength of 1064 nm that has passed through the wavelength conversion element 35 without being converted is converted. The wavelength laser light is reflected by the concave mirror 36 and is incident on the wavelength conversion element 35 again, and is converted into a half-wavelength laser light having a wavelength of 532 nm. The half-wavelength laser light having a wavelength of 532 nm is reflected by the film 44 of the wavelength conversion element 35 and is emitted from the wavelength conversion element 35.

  Here, the laser beam B1 incident on the wavelength conversion element 35 from the solid-state laser element 34, wavelength-converted by the wavelength conversion element 35, and emitted from the wavelength conversion element 35, and once reflected by the concave mirror 36 are wavelength-converted. In a state where the laser beam B2 incident on the element 35, reflected by the film 44 and emitted from the wavelength conversion element 35 overlaps with each other, the half-wavelength laser light having a wavelength of 532 nm and the fundamental wavelength laser light having a wavelength of 1064 nm interfere with each other. Cause output to drop.

  Therefore, here, the wavelength conversion element 35 is inclined with respect to the optical axis direction so that the laser light beams B1 and B2 do not overlap each other by the refracting action on the incident surface 35a and the exit surface 35b, and the wavelength is 532 nm. Thus, interference between the half-wavelength laser beam and the fundamental wavelength laser beam having a wavelength of 1064 nm is prevented, so that a reduction in output can be avoided.

  The glass cover 37 shown in FIG. 2 is formed with a film that does not transmit these laser beams in order to prevent the excitation laser beam having a wavelength of 808 nm and the fundamental wavelength laser beam having a wavelength of 1064 nm from leaking to the outside. ing. Moreover, the hole 39a is provided in the cover body 39 of the green laser light source apparatus 2 shown in FIG. In the green laser light source device 2, the parts other than the cover body 39 are first assembled, and after adjustment of all optical members such as optical axis adjustment is completed, the cover body 39 is attached. Then, an adhesive is injected from the hole 39a so that the green laser light source device 2 does not cause an adjustment shift, and the respective optical members and the surface of the base 38 facing the hole 39a are firmly fixed. Since the adhesive generates gas during the curing process, the hole 39a provided in the cover body 39 also serves as an outlet for the generated gas. When the adhesive is cured and the gas is sufficiently discharged, the sealing member 39b is attached to the cover body 39 so as to cover the hole 39a provided in the cover body 39. Thereby, mixing of the dust etc. into the inside of the green laser light source device 2 is prevented, and the fall of the luminous efficiency of the green laser light source device 2 is avoided.

  FIG. 4 is an internal perspective view of the green laser light source device 2. FIG. 5 is an internal cross-sectional view of the green laser light source device 2.

  As shown in FIG. 4, the semiconductor laser 31, the FAC lens 32, the rod lens 33, the solid-state laser element 34, the wavelength conversion element 35, and the concave mirror 36 are integrally supported by a base 38. The bottom surface 51 of the base 38 is parallel to the optical axis direction. Here, the direction orthogonal to the bottom surface 51 of the base 38 is defined as the height direction, and the direction orthogonal to the height direction and the optical axis direction is defined as the width direction. In addition, the side close to the bottom surface 51 of the base 38 will be described below, and the side opposite to the bottom surface 51 will be described above, but this does not necessarily coincide with the vertical direction of the actual apparatus.

  The semiconductor laser 31 is obtained by mounting a laser chip 41 that outputs laser light on a mount member 52. The laser chip 41 has a long strip shape in the optical axis direction, and is fixed to a substantially central position in the width direction of one surface of the plate-shaped mount member 52 in a state where the light emission surface faces the FAC lens 32 side. Yes. The semiconductor laser 31 is fixed to the base 38 with solder containing a silver paste having high heat resistance. As a result, the heat generated by the laser chip 41 is transmitted to the base 38 and can be dissipated.

  The FAC lens 32 and the rod lens 33 are held by a condenser lens holder 54. The condensing lens holder 54 is supported on the base 38 by an elastic member 55 which is substantially U-shaped and has a distal end side formed like a diaphragm. More specifically, the elastic member 55 is provided between the side wall portion 51 a erected on one side of the portion where the condenser lens holder 54 is disposed on the base 38 and the bottom portion 51 of the base 38. One side surface 55a is first passed through a rectangular hole (not shown). Next, when the corner portion between the side surface 55a and the bottom surface 55b is in a rectangular hole (not shown), the elastic member 55 is rotated so that the bottom surface 55b can pass through the rectangular hole (not shown). . When the corner portion between the bottom surface 55b and the other side surface 55c comes into a rectangular hole (not shown), the elastic member 55 is rotated again and disposed on the bottom surface 51 of the base 38. In this state, the condensing lens holder 54 on which the FAC lens 32 and the rod lens 33 are mounted in advance is an upper portion in the height direction between the side wall portion 51a of the base 38 and one side surface 55a of the elastic member 55. Inserted. At this time, the other side surface 55 c of the elastic member 55 is disposed on the side surface opposite to the condenser lens holder 54 with the side wall portion 51 a of the base 38 interposed therebetween. As described above, the distal end portions of both side surfaces 55a and 55c of the elastic member 55 are formed so as to be narrower than the bottom surface 55b, so that an inward elastic force is generated at the distal end. Thus, the condensing lens holder 54 is pressed and disposed on the side wall 51 a side of the base 38 by the elastic force of the elastic member 55.

  The condensing lens holder 54 arranged as described above is movable in the optical axis direction, whereby the positions of the condensing lens holder 54, that is, the FAC lens 32 and the rod lens 33 are adjusted in the optical axis direction. The FAC lens 32 and the rod lens 33 are fixed to the condenser lens holder 54 with an adhesive before the position adjustment work, and after the position adjustment work, the condenser lens holder 54, the base 38 and the elastic member 55 are made of an adhesive. Fixed to each other.

  The solid-state laser element 34 is supported by a solid-state laser element support portion 56 formed integrally with the base 38. Further, a solid laser element holding portion 57 for holding the solid laser element 34 is provided so as to protrude laterally in a form continuous with the side wall portion. The structures of the solid-state laser element support 56 and the solid-state laser element holding part 57 and the fixing method of the solid-state laser element 34 will be described in detail later.

  The wavelength conversion element 35 is held by a wavelength conversion element holder 58. The wavelength conversion element holder 58 is movable in the width direction with respect to the base 38 so that the position of the wavelength conversion element 35 in the width direction and the inclination angle with respect to the optical axis direction can be adjusted. It is provided so as to be rotatable around an axis substantially orthogonal to the direction. The wavelength conversion element 35 is fixed to the wavelength conversion element holder 58 with an adhesive before the position adjustment work, and after the position adjustment work, the wavelength conversion element holder 58 and the base 38 are fixed to each other with an adhesive. The concave mirror 36 is supported by a concave mirror support portion 59 formed integrally with the base 38. The adhesive used for fixing each member, for example, the wavelength conversion element holder 58 and the base 38, is preferably a UV curable adhesive, for example.

  FIG. 6 is a perspective view of the wavelength conversion element 35. As shown in FIG. 6, the wavelength conversion element 35 has a substantially rectangular parallelepiped shape and includes a periodic polarization inversion structure in which polarization inversion regions 61 and non-polarization inversion regions 62 are alternately formed in a ferroelectric crystal. Therefore, the fundamental wavelength laser beam is incident in the polarization inversion period direction (the arrangement direction of the polarization inversion regions 61). As a result, it is possible to obtain a laser beam having a double frequency, that is, a half wavelength, by the second harmonic generation of incident light by quasi phase matching. As the ferroelectric crystal, for example, LN (lithium niobate) added with MgO is used.

  In order to form a periodic domain-inverted structure, an electric field in the direction opposite to the polarization direction is applied to a unipolar ferroelectric crystal using the periodic electrode 63 and the counter electrode 64. As a result, the polarization direction of the portion corresponding to the periodic electrode 63 is reversed, and the domain-inverted region 61 is formed in a wedge shape from the periodic electrode 63 toward the counter electrode 64.

  As shown in FIG. 6, the domain-inverted region 61 has a wedge shape that gradually decreases in thickness along the depth direction, and wavelength conversion is performed in the depth direction of the domain-inverted region 61 with respect to incident laser light. By moving the element 35, the ratio between the polarization inversion region 61 and the non-polarization inversion region 62 located on the optical path of the laser light changes, and the wavelength conversion efficiency changes accordingly. Therefore, the position of the wavelength conversion element 35 with respect to the optical axis of the laser beam is adjusted so that the wavelength conversion efficiency is maximized, that is, the output of the laser beam is maximized. The position adjustment of the wavelength conversion element 35 will be described in detail later.

  In FIG. 6, for convenience of explanation, the periodic electrode 63 and the counter electrode 64 are shown on the side surfaces 35c and 35d of the wavelength conversion element 35. However, the periodic electrode 63 and the counter electrode 64 are removed by polishing at the stacking stage. The

  FIG. 7 is a diagram illustrating a change state of the wavelength conversion efficiency η according to the inclination angle θ of the wavelength conversion element 35 with respect to the optical axis direction. The wavelength conversion efficiency η of the wavelength conversion element 35 changes according to the inclination angle θ of the wavelength conversion element 35 with respect to the optical axis direction, and in a state where the wavelength conversion element 35 is not inclined with respect to the optical axis direction (θ = 0), the wavelength conversion efficiency η The wavelength conversion efficiency η can be increased by tilting with respect to the optical axis direction.

  When the tilt angle θ is 0, as shown in FIG. 3, the laser beam beams B1 and B2 overlap each other, so that the half-wavelength laser beam having a wavelength of 532 nm and the fundamental wavelength laser beam having a wavelength of 1064 nm interfere with each other. By tilting the wavelength conversion element 35 with respect to the optical axis direction, the laser beams B1 and B2 are shifted due to refraction at the entrance surface 35a and the exit surface 35b. Can tilt output drop.

  In particular, here, the wavelength conversion element 35 is inclined so as to enter a high-efficiency region within a required range (for example, ± 0.4 degrees) centered on a peak point of wavelength conversion efficiency (here, θ = ± 0.6 degrees). The angle θ is adjusted, and the dimensions of each part are set so that the wavelength conversion element holder 58 can be tilted with respect to the base 38 within an angle range corresponding to the adjustment allowance.

  FIG. 8 is a functional block diagram of the image display apparatus 1 shown in FIG. The control unit 157 includes a laser light source control unit 71 that controls the laser light source devices 2 to 4 for each color, a video signal conversion unit 72 that converts a video signal input from the portable information processing device 151, and an output signal thereof. The image display control unit 74 including the spatial light modulation element control unit 73 that controls the spatial light modulation element 25 and the power supplied from the portable information processing device 151 to the laser light source control unit 71 and the image display control unit 74. The power supply part 75 to supply and the main control part 76 which controls each part collectively are provided.

  Based on the image display signal input from the image display control unit 74, the main control unit 76 permits the lighting of the laser light source devices 2 to 4 as control signals for controlling the lighting of the laser light source devices 2 to 4 of the respective colors. A lighting permission signal (LD ON) and a red lighting signal (LD RON), a green lighting signal (LD GON), and a blue lighting signal (LD BON) for lighting the red, green and blue laser light source devices 2 to 4 respectively. These control signals are generated and output to the laser light source controller 71.

  The laser light source control unit 71 generates drive control signals (Ig, Ir, and Ib) for controlling application of drive current to the laser light source devices 2 to 4 based on the control signal input from the main control unit 76. Output to laser light source devices 2-4.

  The spatial light modulator control unit 73 is configured to control the operation of the spatial light modulator 25 based on the video signal output from the video signal converter 72 as a reference voltage signal (LCOS VCOM) and a pixel voltage signal (LCOS). ΔV) is generated, and these control signals are output to the spatial light modulator 25. In actuality, the pixel voltage signal (LCOS ΔV) has the same number of signals as the number of pixels of the spatial light modulation element 25, but in the present embodiment, for convenience, the nth pixel of the spatial light modulation element 25. The pixel voltage signal is described as “LCOS ΔV”.

  The spatial light modulation element 25 is a reflective liquid crystal display element, so-called LCOS (Liquid Crystal On Silicon), and the laser light transmitted through the liquid crystal layer formed on the silicon substrate is reflected by the reflection layer on the silicon substrate and emitted. It is the thing of the structure to make it. In this spatial light modulation element 25, the output (luminance) of the laser light increases or decreases in accordance with the pixel voltage signal (LCOS ΔV) input from the spatial light modulation element control unit 73, and the time from the laser light source devices 2 to 4 for each color. A desired hue can be displayed by increasing or decreasing the output of the laser light of each color input in the division.

  The spatial light modulator 25 is controlled in polarity (p and n) based on the reference voltage signal (LCOS VCOM) input from the spatial light modulator control unit 73, and the pixel voltage signal (LCOS ΔV) is The sign is inverted according to the reference voltage signal (LCOS VCOM).

  FIG. 9 shows a lighting sequence in a normal operation in which white display is performed by a first normal lighting sequence for lighting the green laser light source device 2, the red laser light source device 3, and the blue laser light source device 4, and the operation of the spatial light modulator 25. It is a figure which shows the relationship.

  In the example shown in FIG. 9, one frame is divided into three lighting sections (subframes), and each frame is displayed to light green, red, and blue once. Red, green, and blue are displayed in one frame. Light up in the order of.

  As described above (see also FIG. 8), the lighting permission signal (LD ON), the red lighting signal (LD RON), the green lighting signal (LD GON), and the blue lighting signal (LD BON) are mainly used. When the lighting permission signal (LD ON) is output from the control unit 76 to the laser light source control unit 71, the red lighting signal (LD RON), the green lighting signal (LD GON), and the blue lighting signal (LD BON) are turned on. Thus, the red, green and blue laser light source devices 2 to 4 are turned on.

  Further, the reference voltage signal (LCOS VCOM) and the pixel voltage signal (LCOS ΔV) are output from the spatial light modulation element control unit 73 to the spatial light modulation element 25, and the spatial light modulation element 25 according to the reference voltage signal (LCOS VCOM). Are switched, the transmittance of the spatial light modulator 25 is changed according to the pixel voltage signal (LCOS ΔV), and the output (luminance) of each color laser beam is adjusted.

  Here, when displaying white, the spatial light modulator 25 may modulate the red, green, and blue lasers, and the absolute value of the pixel voltage signal (LCOS | ΔV |) is the same for all of red, green, and blue. In the lighting sections A1 to A6, B1 to B6, and C1 to C3, the lowest voltage is obtained, and the output (luminance) is the maximum level (255). Here, since the RGB lighting pattern that lights in the order of red, green, and blue is adopted, laser light is output to the spatial light modulator 25 in the order of red, green, and blue.

  However, the green laser light source device 2 has a low oscillation efficiency at low temperatures and takes time to start up. FIG. 10 is a diagram showing an output immediately after the green laser light source device 2 starts to be turned on by the first normal lighting sequence shown in FIG. As shown in FIG. 10, it takes about 90 seconds after the start-up until the green output is stabilized and becomes, for example, a predetermined value of 0.25 W or more. For this reason, green cannot be displayed for a while after the image display device 1 is activated, or the amount of light that can be balanced with the laser light of other colors cannot be obtained, and a desired image display cannot be performed. Problems arise. For example, when a white image is displayed immediately after startup, green cannot be displayed, and a magenta color that is a mixed color of red and blue is obtained. Moreover, the display color changes with time and gradually approaches the display color that should normally be. Such an abnormal display color change state occurs not only in the white image but also in other images and videos. Therefore, since the user sees an image or video having a display color different from what he / she has as a prejudice, the image display device 1 may have failed even though it is not actually a failure. It will be misunderstood.

  In order to improve this, for example, the control shown in FIG. 11 may be performed. FIG. 11 shows a first sequence for activating the green laser light source device 2 while turning on the green laser light source device 2, the red laser light source device 3, and the blue laser light source device 4 in the first normal lighting sequence and performing blue display. FIG. 6 is a diagram illustrating a relationship between a warm-up sequence of 1 and the operation of the spatial light modulation element 25.

  In this embodiment, in addition to the sections A2, A5, B2, B5, C2,... In which the green laser light source device 2 is normally lit, the sections in which the laser light source devices other than green are lit (in FIG. 11, the red light is turned on). In the sections A1, A4, B1, B4, C1,...), The green laser light source device 2 is turned on. That is, originally, the lighting allocation sections A1, A4, B1, B4, C1,... Of the red laser light source device 3 are additionally used for lighting the green laser light source device 2. In addition, the lighting sections A1, A4, B1, B4, C1,... Of the green laser light source device 2 that are additionally allocated are used as the lighting sections A2, A5, B2, B5, By adjoining C2..., The overall lighting section of the green laser light source device 2 is lengthened, thereby promoting the heat generation of the excitation laser and improving the excitation efficiency. As a result, the green laser light source device 2 Startup time can be shortened. Although it takes time to start up the green laser light source device 2 at a low temperature, the start-up time can be shortened by the heat generated by the laser itself by taking this embodiment.

  In the first warm-up sequence shown in FIG. 11, the lighting sections A3, A6, B3, B6, and C3 of the blue laser light source device 4 are not additionally used for lighting the green laser light source device 2. The lighting time of the blue laser light source device 4 is used, for example, to project only blue for a certain time from when the image display device 1 is activated until the output of the green laser light is considered to be stable. That is, so-called blue back display. If the blue background is displayed in this manner, even if the output of the green laser is not stable, no abnormality is seen in the projected image, so there is no problem.

  FIG. 12 is a diagram showing an output when the green laser light source device is activated in the first warm-up sequence. The points represented by white squares are due to the lighting sequence during the normal operation in which white display is performed by the first normal lighting sequence shown in FIG. 9, which is the same as FIG. A point represented by a black square corresponds to the case where the activation is performed by the first warm-up sequence shown in FIG. After the start-up, the green output is shortened to 20 seconds, for example, until it stabilizes to a predetermined value of 0.25 W or more, so that the desired image display time can be shortened from 90 seconds to 20 seconds. As a result, it is possible to quickly switch to displaying a video desired by the user.

  In addition, until the amount of light emitted from the green laser light source device 2 is equal to or greater than a predetermined value, the section in which the green laser light source device 2 is turned on (lighting sections A1, A2, A4, A5, B1, B2, In B4, B5, C1, C2,..., The spatial light modulation element 25 is controlled so that the output light from the green laser light source device 2 is not projected to the outside, and the light source devices other than green are turned on (see FIG. 11, in the blue lighting sections A3, A6, B3, B6, C3...), The spatial light modulation element 25 is controlled so that the output light from the light source device is projected to the outside. The feeling of anxiety given can be resolved.

  In the present embodiment, the blue background is displayed for a certain time immediately after the image display device 1 is activated. However, if any of the lighting sections of the laser light source device other than the green light source is used to turn on the green laser light source and the control is performed so that the green laser light is not projected to the outside when the green laser light source is turned on, the display image is displayed. Does not have to be limited to a blue back. For example, a blue back may be displayed when normal, and a red back may be displayed when abnormal. Or you may make it display the start-up time meter using other than green and display the remaining time until start-up, or display the company logo, device operation method, and notes using other than green , Etc. may be displayed. In this case, while increasing the number of sections in which the green laser light source device 2 is turned on, blue and red are turned on every other frame in a section in which light sources other than green are turned on to perform color expression.

  As described above, the method of accelerating the activation of the green laser light source device 2 has been described using an example in which one frame is divided into three lighting sections and the laser light source devices 2 to 4 are turned on in the order of red, green, and blue. The lighting pattern of the laser light source devices 2 to 4 in the invention is not limited to this. The light emitted from the laser light source devices 2 to 4 of each color may be different from the standard green, red, and blue colors on the CIExy chromaticity diagram. Therefore, the drive duty of the laser light source devices 2 to 4 for each color in one frame is set so that the color shift of the projected image is as small as possible.

  FIG. 13 is a diagram illustrating an example of another normal lighting sequence for lighting the green laser light source device 2, the red laser light source device 3, and the blue laser light source device 4. For example, as in the second normal lighting sequence shown in FIG. 13A, one frame is divided into four lighting sections, and the laser light source devices 2 to 4 are turned on in the order of red, green, blue, and green. Also good. Here, a GR lighting pattern that lights in the order of green and red exists across two adjacent frames. That is, green is lit in the last lighting section of the frame, and red is lit in the first lighting section of the next frame. In addition, there is a GBG lighting pattern that lights in the order of green, blue, and green in one frame. In such a lighting pattern, the number of times green light is turned on in one frame is two times, whereas the number of times red light and blue light are turned on once. The number of green lighting is greater than the number of blue lighting. For this reason, even if the switching speed of the laser light source devices 2, 3 and 4 and the response speed of the spatial light modulator 25 are not high, color braking (rainbow phenomenon) can be efficiently reduced.

  Further, as in the third normal lighting sequence shown in FIG. 13B, one frame is divided into five lighting sections, and the laser light source devices 2 to 4 are turned on in the order of red, green, red, blue, and green. May be. Here, as in the second normal lighting sequence shown in FIG. 13A, a GR lighting pattern that lights in the order of green and red exists across two adjacent frames.

  In this third normal lighting sequence, the number of times red and green are lit twice in one frame, whereas the number of times blue is lit is one, red and green having high visibility in one frame. The number of lighting is greater than the number of blue lighting. For this reason, even if the switching speed of the laser light source devices 2 to 4 and the response speed of the spatial light modulator 25 are not high, the color braking (rainbow phenomenon) can be efficiently reduced.

  Further, in the third normal lighting sequence, since the number of lighting sections constituting one frame is an odd number, the polarity of the spatial light modulation element 25 is reversed for each lighting section of each frame, and in each lighting section. If the polarity of the spatial light modulator 25 is the same in each frame, the last lighting section of the frame and the first lighting section of the next frame have the same polarity, and the residual charge generated in the spatial light modulator 25 is lit. It is not possible to cancel each section reliably.

  Therefore, here, the polarity of the spatial light modulator 25 is reversed for each lighting section, and is switched so that the corresponding lighting sections in the adjacent frames have opposite polarities. As a result, the polarity of the spatial light modulation element 25 is reversed for each lighting section exceeding one frame, so that the residual charge generated in the spatial light modulation element 25 can be reliably canceled for each lighting section. Thus, the burn-in of the spatial light modulator 25 can be prevented.

  FIG. 13C is a diagram illustrating the order in which the red, green, and blue laser light source devices 2 to 4 are turned on and the polarity of the spatial light modulator 25 according to the fourth normal lighting sequence. Here, similarly to the second normal lighting sequence shown in FIG. 13A, the laser light source devices 2 to 4 are lit in the order of red, green, blue, and green, but one frame is divided into four lighting groups. In addition, each lighting group is divided into two lighting sections so that the same color is lit twice in succession.

  When the same color is continuously turned on a plurality of times in this way, the lighting time for one time in each of the laser light source devices 2 to 4 is shortened. The low rise response of the light modulation element 25 can be compensated.

  Further, when the same color is continuously lit multiple times in this way, the lighting pattern indicating the lighting order of the laser light source devices 2 to 4 may be considered in units of lighting groups, and this fourth normal lighting sequence. However, as in the second normal lighting sequence, it has a GR lighting pattern and a GBG lighting pattern. The green output shortage due to the rising response of the spatial light modulator 25 and the green color emitted by the green laser light source device 2 By canceling out the hue shift of the laser light itself, the displayed yellow and cyan hue shifts can be reduced.

  In the second to fourth normal lighting sequences described above, there is no independent RG lighting pattern that does not overlap with the GR lighting pattern, but such an independent RG lighting pattern is a GR lighting. A configuration mixed with a pattern is also possible. As described above, the present invention reduces the hue shift of the intermediate color by generating a green output shortage by the GR lighting pattern and canceling out the hue shift of the green laser light itself. Since the pattern causes a shortage of red output, the effect of the GR lighting pattern is reduced. Therefore, in the configuration in which independent RG lighting patterns are mixed with the GR lighting patterns, it is preferable that the GR lighting patterns exist the same number of times as the independent RG lighting patterns or more times per frame. Thereby, the influence of the independent RG lighting pattern can be suppressed, and the hue shift of the intermediate color can be reduced.

  Further, instead of the second to fourth normal lighting sequences described so far, at the time of startup, a warm-up sequence for accelerating the startup of the green laser light source device is provided as in the first lighting sequence. Also good. For example, in the second normal lighting sequence shown in FIG. 13A, green (G) is turned on instead of red (R) in the first lighting section of each frame. The warm-up sequence of If it does so, green (G) will be continued using three lighting sections ranging from the green (G) which is lit in the fourth lighting section to the first lighting section and the second lighting section in the next frame. Will light up. Thus, the start of the green laser light source device can be accelerated by the second warm-up sequence.

  In the third normal lighting sequence shown in FIG. 13B, green (G) is turned on instead of red (R) in the first and third lighting sections of each frame. Is the third warm-up sequence. If it does so, green (G) will be continuously used using four lighting sections ranging from the green (G) to light in the fifth lighting section to the first to third lighting sections in the next frame. Will light up. Thus, the start of the green laser light source device can be accelerated in the third warm-up sequence.

  Further, in the fourth normal lighting sequence shown in FIG. 13C, in the first lighting group of each frame, green (G) is lit instead of red (R). The warm-up sequence of Then, the green color (G) that is lit in the fourth lighting group and the first and second lighting groups in the next frame are used to indicate the green color using three lighting sections (that is, six lighting sections). (G) lights up continuously. Thus, the start of the green laser light source device can be accelerated in the fourth warm-up sequence.

  The main parts of the present invention in the green laser light source device having the above-described configuration and the image display device on which the green laser light source device is mounted will be described.

  FIG. 14 is a perspective view showing a solid laser element 34 and a base 38 that supports the solid laser element 34 among the components constituting the green laser light source device 2. FIG. 15 is an enlarged perspective view of the solid-state laser element 34 and its peripheral portion in FIG. FIG. 16 is a top view of the green laser light source device shown in FIG.

  In particular, as shown in FIG. 14, the solid-state laser element 34 has a substantially rectangular parallelepiped shape, and is parallel to the optical axis direction of the output light from the semiconductor laser 31, that is, among the four surfaces excluding the entrance surface and the exit surface, The base 38 abuts on two surfaces adjacent to each other. In the present embodiment, the bottom surface (the minus side in the height direction) of the solid-state laser element 34 is the solid-state laser element support portion 56 of the base 38 and one of the side faces (the plus side in the width direction) is the base. The solid-state laser element holding portions 57 of 38 are in contact with each other. Here, as described above, the output light from the semiconductor laser 31 has a direction that spreads at an abrupt angle. In the case of the present embodiment, it is the first axis of the semiconductor laser 31, that is, the height direction in FIG. This is first focused by the FAC lens 32. However, although the output light from the semiconductor laser 31 is not as high as the previous height direction, it is radiated while spreading to the slow axis of the semiconductor laser 31 orthogonal thereto, that is, the width direction in FIG. This is focused by the rod lens 33. Therefore, the fixed position of each component is determined at the design stage so that the output light from the semiconductor laser 31 is focused on the approximate center of the incident surface of the solid-state laser element 34 by the FAC lens 32 and the rod lens 33.

  In particular, as can be further understood in FIG. 16, in the width direction of the FAC lens 32, the rod lens 33, and the solid-state laser element 34, the assumed optical axis of the semiconductor laser 31 is set so that they are attached at predetermined positions. In parallel, the plurality of mounting contact surfaces are arranged. These mounting contact surfaces are arranged so that the optical axis emitted from the semiconductor laser 31 passes through the center of each component of the FAC lens 32, the rod lens 33, and the solid-state laser element 34. In other words, the positions of the FAC lens 32, the rod lens 33, and the solid-state laser element 34 are fixed by the mounting contact surface in the width direction that is the slow axis. The reason for such a configuration will be described below. First, since the FAC lens 32 does not have lens power in the width direction, positioning accuracy in the width direction is not high, and the contact surface can be fixed. On the other hand, the rod lens has a lens power in the width direction, but is a slow axis, so the positional accuracy is not higher than that of the first axis, and the contact surface can be fixed. On the other hand, since the first axis has a larger spread angle than the slow axis, the capture efficiency is increased, and when a small lens is used, that is, when a small lens such as the FAC lens 32 is used, the semiconductor laser 31 and the FAC lens 32 are used. Needs to be close to about 0.1 to 0.3 mm and 1 mm or less. Therefore, the position of the FAC lens 32 needs to be accurately arranged with respect to the semiconductor laser 31. For this reason, the contact surface is fixed at least in the width direction.

  The semiconductor laser 31 used in the present embodiment is a watt class high-power semiconductor laser. A high-power semiconductor laser is a laser whose transverse mode is generally multimode. In other words, compared to a single mode semiconductor laser, the emitter is longer in the width direction, and the spread angle of the laser has a feature that the emitter width direction, that is, the slow axis is smaller.

  For this reason, the semiconductor laser 31 has a larger emitter width direction than the emitter thickness direction. For example, the width of the emitter is 0.05 to 0.3 mm, and the thickness of the emitter is 0.001 to 0.003 mm. When such a semiconductor laser 31 is focused on a solid-state laser element, it is preferable to reduce the beam diameter and the NA. This is because such a configuration can increase the coupling efficiency of the resonator composed of the solid-state laser element and the mirror. In such a case, the beam condensed inside the solid-state laser element becomes a long beam in the emitter width direction. Therefore, the solid-state laser element 34 has a shape that is longer in the width direction than in the height direction. As a result, an attachment error occurs, and even if the output light from the semiconductor laser 31 is slightly deviated from the center of the laser light incident surface from the semiconductor laser 31 of the solid-state laser element 34, it is used for excitation by the solid-state laser element 34. The influence given can be reduced.

  As shown in FIG. 15, the solid-state laser element 34 of the present embodiment is in contact with the base 38 also at the bottom side corner of the incident surface. However, the contact portion on the incident surface is provided at a position where the output light from the semiconductor laser 31 is not blocked. And as shown in FIG. 16, the solid-state laser element 34 is fixed as follows. That is, first, the adhesive is dropped into the space 57a on the side surface that contacts the solid laser element holding portion 57 of the base 38. A convex portion 56 b is provided on the solid laser element support portion 56 on the opposite side of the solid laser element holding portion 57 across the solid laser element 34. Adhesive is also dropped into the space 56a between the convex portion 56b and the central portion of the side surface in the optical axis direction of the solid-state laser element 34 facing the convex portion 56b. In this way, the solid-state laser element 34 is fixed to the base 38. Examples of the adhesive used at this time include a so-called instantaneous adhesive and a photo-curable adhesive. As described above, if the convex portion 56b is provided on the solid laser element support portion 56, the adhesive for fixing the solid laser element 34 can be prevented from flowing out before being cured.

  As shown in the present embodiment, there may be three or more surfaces where the solid-state laser element 34 abuts the base 38, but at least four surfaces excluding the incident surface and the exit surface are adjacent to each other. It is preferable that the two surfaces to be brought into contact with the base 38. Then, the solid laser element 34 is prevented from rotating around the height direction axis and the width direction axis in FIG. In particular, since the influence of the unbalance of the shrinkage force generated at the time of curing of the adhesive is reduced, such rotation is further suppressed. As a result, the solid-state laser element 34 is attached to the base 38 so that the incident surface and the emission surface thereof are orthogonal to the optical axis of the output light from the semiconductor laser 31.

  By the way, in the present embodiment, the contact surface of the solid-state laser element 34 with the base 38 is not in contact with the base 38 over the entire surface. In particular, as shown in FIG. 15, the solid-state laser element 34 is supported by contacting the bottom surface thereof with three convex portions 56 c provided on the solid-state laser element support portion 56 of the base 38 (so-called “three-point support”). "). One side surface adjacent to the bottom surface is in contact with two convex portions 57 b and 57 c provided on the solid laser element holding portion 57 of the base 38 (so-called “two-point contact”). That is, the solid laser element 34 and the base 38 are in contact with each other with a contact area smaller than the surface area of each of the surfaces of the solid laser element 34. The fact that the partial contact is made instead of the full contact is actually a great reason other than the effect of suppressing the rotation of the solid-state laser element 34 around the height direction axis and the width direction axis in FIG. . This will be described below with reference to FIG.

  FIG. 17 is a diagram showing the operating characteristics of the green laser light source device 2 of the present embodiment. (A) is a conventional operating characteristic in which the solid laser element 34 and the fixed surface of the base 38, that is, the solid laser element support part 56 and the solid laser element holding part 57 are in full contact. FIG. 15B shows the operation of the present invention in which the fixed surfaces of the solid-state laser element 34 and the base 38, that is, the solid-state laser element support portion 56 and the solid-state laser element holding portion 57 are partially contacted as shown in FIG. It shows the characteristics. Moreover, in these FIG. 17, a solid line is a thing at the time of carrying out the pulse drive of the green laser light source device 2, and a dotted line is a CW drive (continuous wave (continuous wave) drive), ie, the drive which supplied the constant electric current continuously. It is a thing when it goes.

  In each diagram of FIG. 17, the horizontal axis indicates the current value input to the semiconductor laser 31. In other words, this is proportional to the power of the output light (808 nm) from the semiconductor laser 31. The vertical axis indicates the power of the excitation light (1064 nm) output from the solid-state laser element 34 in response to the output light (808 nm) from the semiconductor laser 31. Note that the current supplied to the semiconductor laser 31 flows from the electrode 53 through the laser chip 41 in FIG. 14 to the bottom of the mount member 52 and the base 38 to which it is bonded.

  Returning to FIG. 17, if the solid-state laser element 34 and the fixed surface of the base 38 are brought into full contact with each other, the green laser light source device 2 having such a configuration as shown in FIG. Whether the drive is performed or the CW drive is performed, the characteristics are substantially the same. That is, in any driving method, the current value input to the semiconductor laser 31 and the power of the excitation light output from the solid-state laser element 34 as a result are in a substantially proportional relationship. This is because the contact area between the solid laser element 34 and the fixed surface of the base 38 is large, and the heat generated from the solid laser element 34 upon receiving the output light from the semiconductor laser 31 is efficiently radiated.

  However, when the solid-state laser element 34 and the fixed surface of the base 38 are in partial contact as in the present embodiment, the green laser light source device 2 having such a configuration has the following effects: Different operation characteristics are exhibited when the CW drive is performed. That is, when pulse driving is performed, the current value input to the semiconductor laser 31 and the power of the excitation light output from the solid-state laser element 34 as a result are substantially proportional to each other as in the case of full contact. . On the other hand, when CW driving is performed, even if the current value input to the semiconductor laser 31 is increased, the power of the pumping light output from the solid-state laser element 34 does not increase so much. Will fall. This is because the contact area between the solid-state laser element 34 and the fixed surface of the base 38 is smaller than in the case of full contact, and the heat radiation efficiency from the solid-state laser element 34 is reduced. However, the heat dissipation efficiency is ensured to the extent that it has the same operating characteristics as the case of full contact in pulse driving.

  As shown in FIGS. 9 and 13, the image display device 1 according to the present embodiment alternately turns on the green laser light source device 2, the red laser light source device 3, and the blue laser light source device 4 in one frame. While displaying the image. That is, all of the green laser light source device 2, the red laser light source device 3, and the blue laser light source device 4 are always pulse-driven. The spatial light modulator of this embodiment operates at 57 Hz (17.5 msec) per frame. The drive duty of the green laser light source device 2 in the normal lighting sequence (see FIGS. 9 and 13) does not exceed 50% of one frame. Incidentally, even when the green laser light source device 2 is driven alone, it is confirmed by experiment that the green laser light source device 2 outputs green laser light until the drive duty becomes 50% of the one frame. did.

  As described above, during normal operation, that is, in a state where the green laser light source device 2 is incorporated in the image display device 1, the green laser light source device 2 is always operated by pulse driving, and green light is output without any problem. There is no loss of operation. And when it is not used in such a normal state, the output of green light becomes small. As a result, even if the green laser light source device 2 is detached from the main body of the image display device 1 and a single operation is attempted, the safety is higher than that in the case of full contact.

  More specifically, it is as follows. At present, there is no high-power green semiconductor laser of course in the world, and the green laser light source device 2 used in this embodiment has a high output and is valuable. Since green light has higher visual sensitivity (degree of feeling brighter) than red and blue, there is a sufficient possibility that such a green laser light source device 2 can be used as a high-intensity laser pointer or ink brush. . As shown in FIG. 2 and the like, the green laser light source device 2 is different from the type in which the green laser light source device 2 is fitted and attached to a holder like the other red and blue semiconductor lasers, and has a protruding mounting portion provided in the optical engine unit 156. It is only screwed to 22. Moreover, there is a gap between the green laser beam exit and the housing 21. From this gap, the emission of green light can be confirmed, and since the green laser light source device has a certain size, it can be easily understood by anyone's eyes that the reference numeral 2 is the green laser light source device. Therefore, the green laser light source device 2 may be removed from the optical engine unit 156 of the image display device 1 and used alone. Of course, it is not assumed that the green laser light source device is used alone for such an application that is not an original image display, which may cause an unexpected situation, which is not preferable.

  Preventing the diversion of components due to disassembly of the image display device itself is one object, but in addition to this, the green laser light source device 2 outputs infrared light therein. That is, the output light (808 nm) of the semiconductor laser 31 and the excitation light (1064 nm) received and converted by the solid-state laser element 34. In the worst case, if such light leaks due to the wavelength conversion element 35 dropping off, the person handling it does not know that infrared light is being output. The infrared light will continue to shine for a long time, which is very dangerous.

  Therefore, in the present embodiment, as shown in FIG. 15 in particular, the solid laser element 34 of the green laser light source device 2 and the fixed surface of the base 38 are not brought into full contact with each other, and the contact area thereof is determined as a solid laser. Each surface of the element 34 is smaller than the surface area. Even in such a partial contact, since the green laser light source device 2 is always operated by pulse driving during normal operation, that is, in a state of being incorporated in the image display device 1, green light is output without any problem. The operation as an image display device is not impaired. A person who removes the green laser light source device 2 and intends to use it for other purposes should first apply a constant current to the green laser light source device 2 to try a single operation. However, in that case, as described with reference to FIG. 17, the output of the excitation light (1064 nm) from the solid-state laser element 34 in the interior does not affect the human body or satisfies the safety standard. It becomes small to the level. As a result, the output of green light is of course not at a level that can be used as the light source of the image display device, and is significantly smaller than the level expected by those who intend to divert it. If the output of the green light is reduced, the person who tries to divert it assumes that the green laser light source device has failed and is less likely to try further operations. Thus, even if the green laser light source device 2 is detached from the main body of the image display device 1 and a single operation is attempted, the safety is further enhanced as compared with the case of full contact.

  Such a configuration of the green laser light source device 2 exhibits its effect even when the image display device 1 is warmed up. In FIG. 11, during the warm-up of the image display device 1, in addition to the section in which the green laser light source device 2 is turned on, the section in which the laser light source devices other than green are lit (in FIG. 11, the red light source is turned on). It has been described that the green laser light source device 2 is turned on. As a result, the overall lighting section of the green laser light source device 2 is lengthened, thereby promoting the heat generation of the excitation laser and improving the excitation efficiency. As a result, the startup time of the green laser light source device 2 can be shortened. it can.

  At this time, as can be seen from FIG. 11, the drive duty of the green laser light source device 2 exceeds 50%, but the solid laser element 34 and the base 38 (see FIG. 15) of the green laser light source device 2 are connected. In the case of conventional full contact, green light is output even in this state. Therefore, the spatial light modulator 25 (see FIG. 2) is controlled by the signals LCOS_VCOM and LCOS_ | ΔV | so that the output light from the green laser light source device 2 is not projected to the outside.

  However, as shown in the present embodiment, when the solid-state laser element 34 and the base 38 of the green laser light source device 2 are in partial contact (see FIG. 15), the drive duty exceeds 50%. The output of 1064 nm infrared light is reduced from the solid-state laser element 34. As a result, the output of green light from the green laser light source device 2 is also reduced. Therefore, leakage of green light during warm-up can be prevented more reliably, and excessive leakage of green light can be avoided even if the spatial light modulator 25 fails. Nevertheless, since a current flows through the semiconductor laser 31, 808 nm light is output from the semiconductor laser 31, and the solid laser element 34 is continuously irradiated with the light. The point that the irradiation energy warms the solid-state laser element 34 is not different from the case of the conventional full contact. Therefore, the first warm-up sequence for accelerating the start-up of the green laser light source device 2 shown in FIG. 11 functions sufficiently even with the partial contact structure (see FIG. 15) employed in the present embodiment. To do. Of course, the same applies to the second to fourth warm-up sequences described above with reference to FIG.

  As described above, according to the present invention, even if the laser light source device by wavelength conversion is removed, the laser light source device can operate only at a low output by itself, while the laser light source device is normally incorporated. In the case where the light is in the green state, green laser light is emitted. Accordingly, even if the green laser light source device is detached from the main body of the image display device and operated alone without impairing the operation as the image display device, the safety is further improved.

  The laser light source device according to the present invention and the image display device on which the laser light source device is mounted do not impair the operation as the image display device. However, the output of the laser light is so low that it does not affect the human body, so that it is useful as a time-division display type image display device equipped with a laser light source device using a semiconductor laser as a light source. .

DESCRIPTION OF SYMBOLS 1 Image display apparatus 2 Green laser light source apparatus 3 Red laser light source apparatus 4 Blue laser light source apparatus 5 Spatial light modulator 6 Polarization beam splitter 7 Relay optical system 8 Projection optical system 11-13 Collimator lenses 14, 15 1st and 2nd Dichroic mirror 16 Diffuser 17 Field lens 21 Housing 22 Mounting portion 23 Front wall portion 24 Side wall portion 25, 26 Holder 27, 28 Mounting hole 31 Semiconductor laser 32 FAC (Fast-Axis Collimator) lens 33 Rod lens 34 Solid laser element 35 Wavelength conversion element (optical element)
35a Incident surface 35b Emission surface 35c, 35d Side surface 36 Concave mirror 37 Glass cover 38 Base 39 Cover body 41 Laser chip 42, 43, 44, 45, 46 Film 51 Bottom surface 51a Side wall portion 52 Mount member 53 Electrode 54 Condensing lens holder 55 Elastic member 56 Solid laser element support part 57 Solid laser element holding part 58 Wavelength conversion element holder 59 Concave mirror support part 61 Polarization inversion area 62 Non-polarization inversion area 63 Periodic electrode 64 Counter electrode 151 Portable information processing apparatus 152 Main body 153 Keyboard 154 Housing 155 Movable body 156 Optical engine unit 157 Control unit

Claims (2)

A semiconductor laser that outputs excitation laser light;
A solid-state laser element that is excited by the excitation laser beam and outputs a basic laser beam; and
An FAC lens that is arranged on the semiconductor laser side and focuses the excitation laser light from the semiconductor laser in the emitter thickness direction in order to focus the excitation laser light from the semiconductor laser on the solid-state laser element;
Similarly, in order to focus the excitation laser light from the semiconductor laser on the solid-state laser element, a rod lens that is disposed on the solid-state laser element side and converges the excitation laser light from the semiconductor laser in the emitter width direction;
A base for supporting the semiconductor laser , the FAC lens, the rod lens, and the solid-state laser element;
The semiconductor laser is a high-power semiconductor laser whose emitter width direction is larger than the emitter thickness direction,
The spread angle of the excitation laser light from the semiconductor laser is smaller in the emitter width direction than in the emitter thickness direction,
The base includes a first surface parallel to the emitter width direction among the four surfaces excluding the incident surface of the excitation laser beam from the semiconductor laser and the emission surface of the basic laser beam included in the solid-state laser element. The first convex portion having three locations provided opposite to each other, and two locations provided to face the second surface adjacent to the first surface of the solid-state laser element and parallel to the emitter thickness direction. A second convex portion, and a third convex portion provided opposite to the second surface of the solid-state laser element and facing the third surface adjacent to the first surface, Have
In the base, the mounting contact surfaces of the FAC lens and the rod lens are on the same emitter width direction side as the second convex portion, in parallel with the optical axis emitted from the semiconductor laser, and from the semiconductor laser. The emission optical axis is disposed so as to pass through the center of each component of the FAC lens, the rod lens, and the solid-state laser element,
The solid-state laser element is in contact with and supported by the first convex portion, is in contact with the second convex portion, and an adhesive is provided in a space surrounded by the second convex portion and the second surface. In addition, the adhesive is fixed by being dropped into a space between the third convex portion and the third surface, and the emitter width direction is longer than the emitter thickness direction of the semiconductor laser. A laser light source device having a substantially rectangular parallelepiped shape. A wavelength conversion element that converts the wavelength of the basic laser light output from the solid-state laser element to generate and output a half-wavelength laser light;
A mirror that reflects the basic laser light that has not been converted by the wavelength conversion element and transmits the half-wavelength laser light; and
The wavelength conversion element can be translated in the depth direction of the domain-inverted region, and is held by a holder that can be tilted with respect to the optical axis direction of the basic laser light,
The holder and the mirror are supported by a base,
The solid-state laser element has a substantially rectangular parallelepiped shape in which the emitter width direction is longer than the emitter thickness direction of the semiconductor laser, and the emitter width direction is the depth direction of the polarization inversion region of the wavelength conversion element. The laser light source device according to claim 1, wherein the laser light source device is arranged as described above.