JP2014138148A - Semiconductor laser, semiconductor laser array and image display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a semiconductor laser in a sealed structure and improve heat transfer of a stem thereby to maintain an operation temperature of the semiconductor laser within a rated operation temperature.SOLUTION: A semiconductor laser array 1 comprises: a plurality of semiconductor laser chips 2, 3, 4 which is manufactured by a semiconductor process and emits predetermined laser beams; a plurality of stems 8, 9, 10 which are internal heat sink structures for mounting the plurality of semiconductor laser chips, respectively; a common external heat sink structure (substrate 11) for mounting the plurality of stems; and a common sealed structure 14 which is mounted on the external heat sink structure and surrounds the plurality of stems for mounting the plurality of semiconductor laser chips.

Description

  The present invention relates to a semiconductor laser, a semiconductor laser array, and an image display device, and is particularly suitable for application to an image display device using a plurality of laser light sources.

  Conventionally, a light source device and an image display device that emit blue and green light using a blue semiconductor laser and a phosphor wheel including a green phosphor instead of an ultra-high pressure mercury lamp have been proposed. Compared with an ultra-high pressure mercury lamp, a blue semiconductor laser can emit light instantaneously and can be turned off instantaneously, so that the time required for preparation and withdrawal of the image display device can be shortened. In addition, the blue semiconductor laser has a longer life than the ultra-high pressure mercury lamp, and thus has a feature that the number of replacement of the light source device can be reduced.

  Patent Document 1 discloses a configuration using a phosphor wheel that includes a green fluorescent reflection portion that emits blue semiconductor laser light as excitation light and a diffuse transmission portion that diffuses and transmits blue semiconductor laser light. . A plurality of semiconductor lasers constituting the blue semiconductor laser light source device have a configuration of a semiconductor laser array arranged on a plane so as to form rows and columns. The blue semiconductor laser light source device is configured by combining a plurality of blue semiconductor lasers and collimating lenses that convert light emitted from each blue semiconductor laser into parallel light.

Japanese Patent No. 471155

  In the light source device disclosed in Patent Document 1, the blue semiconductor laser is mounted on a metal package called a CAN (can) type (205 in FIG. 9 of Patent Document 1). A blue semiconductor laser that can obtain a light output of 1 W or more per one has been put into practical use, and a laser that can obtain a light output of 3 W or more per piece is expected to be put into practical use. In order to obtain a large light output of 3 W or more per unit, it is necessary to adopt a large CAN package having a diameter of 9 mm in order to ensure heat dissipation. On the other hand, in order to reduce the size of the light source device, it is desirable to adopt a smaller CAN package having a diameter of 3.3 mm or a diameter of 5.6 mm. However, the cross-sectional area of the stem, which is the internal heat sink structure to which the semiconductor laser chip manufactured by the semiconductor process is attached, is limited and reduced by the size of the CAN package, and the heat transfer to the external heat sink structure is deteriorated. It becomes impossible to secure heat dissipation.

  In order to confirm this, the present inventors adopted a CAN package having a diameter of 9 mm as a blue semiconductor laser capable of obtaining a light output of 3 W or more, and a total of 26 laser chips with a pitch of 10 mm or more and 5 rows and 6 columns. A prototype was constructed. A forced cooling means composed of Peltier elements or the like was adopted in order to ensure heat dissipation that can always maintain a stem temperature of 50 ° C. or lower. However, the performance of the prototype could not ensure sufficient heat dissipation, and an optical output with a rating of 3 W or more could be obtained only for a short time. From this, in order to ensure sufficient heat dissipation with a rated light output of 3W or higher and a stem temperature of 50 ° C or less at all times, forced cooling means to increase heat dissipation or adopt a stem cross-sectional area more It can be said that the diameter of the CAN package needs to be larger than 9 mm so as to increase.

  However, there is a problem that the forced cooling means for improving the heat radiation performance is large and expensive. Further, increasing the diameter of the CAN package to more than 9 mm has a problem that the dimensions of the semiconductor laser array in the row direction and the column direction become larger and the light source device becomes larger.

  If the frame package is used instead of the CAN package, the cross-sectional area of the stem is limited by the CAN structure and does not become small. Therefore, since the stem can be made larger, there is a possibility that heat transfer to the heat sink can be improved and heat dissipation can be improved. However, the frame package is not hermetically sealed. A blue semiconductor laser, unlike a red semiconductor laser or the like, deteriorates when emitted in the air, and therefore needs to have a sealed structure. Therefore, a frame package cannot be adopted for the blue semiconductor laser.

  Another problem is the problem of optical axis position adjustment. The semiconductor laser terminal of the CAN package is parallel to the outgoing optical axis direction and extends to the side opposite to the traveling direction of the outgoing light. The external heat sink structure that is in contact with the stem, which is the internal heat sink structure, in a heat transferable manner needs to be disposed on the opposite side of the emitted light. At that time, the external heat sink structure is pierced with a hole so that the semiconductor laser terminal contacts and does not short-circuit. If a hole is made in the external heat sink structure, the contact area between the stem and the external heat sink structure is reduced, heat transfer is deteriorated, and heat dissipation is deteriorated. Therefore, the hole through which the terminal passes cannot be enlarged. As a result, adjusting the two-dimensional position of the semiconductor laser with respect to the external heat sink structure in the direction perpendicular to the optical axis of the collimating lens on which the emitted light is incident causes the semiconductor laser terminal to contact the through hole. Impossible. That is, the CAN package has a problem that the optical axis position adjustment and the heat dissipation cannot be achieved at the same time.

  If a semiconductor laser holder is newly added, the position of the semiconductor laser can be adjusted relative to the external heat sink structure. However, since the holder is added to the heat transfer path, the heat transfer of the structure to the heat sink is deteriorated, and the heat dissipation is deteriorated.

  Yet another problem is wiring problems. In order to simultaneously emit a plurality of semiconductor lasers with a small number of wires, it is necessary to wire the semiconductor laser terminals in series. As described above, the semiconductor laser terminal of the CAN package is parallel to the outgoing optical axis direction and extends on the opposite side to the traveling direction of the outgoing light. Accordingly, it is necessary to provide a space for wiring in series with the external heat sink structure, and as a result, heat transfer of the external heat sink structure deteriorates and heat dissipation deteriorates. That is, there is a problem that series wiring and heat dissipation cannot be achieved at the same time.

  The present invention has been made in consideration of the above-mentioned problems. The object of the present invention is to keep the semiconductor laser at an operating temperature within a rating by making the semiconductor laser a sealed structure and improving the heat transfer of the stem. The present invention provides a semiconductor laser array and an image display device that enable this.

  Furthermore, the present invention provides a semiconductor laser, a semiconductor laser array, and an image display device that can adjust the two-dimensional position of the semiconductor laser in the direction perpendicular to the emission optical axis direction without adding a semiconductor laser holder. is there.

  Furthermore, the present invention provides a semiconductor laser array and an image display device that can reduce the wiring in the external heat sink structure, improve the heat transfer of the external heat sink structure, and keep the semiconductor laser at an operating temperature within a rating. It is to provide.

  In order to solve the above problems, a semiconductor laser array according to the present invention includes a plurality of semiconductor laser chips manufactured by a semiconductor process and emitting a predetermined laser beam, and a plurality of internal heat sink structures each mounting a plurality of semiconductor laser chips. A plurality of stems, a common external heat sink structure for mounting the plurality of stems, and a common sealed structure that is mounted on the external heat sink structure and surrounds the plurality of stems for mounting the plurality of semiconductor laser chips. Configured.

  Further, in the present invention, the plurality of semiconductor laser terminals of the plurality of semiconductor laser chips are configured on the stems so as to extend in a direction substantially perpendicular to the direction of the optical axis emitted from the semiconductor laser chips.

  Furthermore, in this invention, it comprised so that aerial wiring might be connected in series between these semiconductor laser terminals.

  According to the present invention, since a sealed structure surrounding a plurality of semiconductor lasers is used instead of CAN, the cross-sectional area of the stem on which the semiconductor laser chip is mounted can be increased without being restricted by CAN. Therefore, the heat transfer of the stem which is an internal heat sink structure is improved, the heat transfer to the external heat sink structure is improved, and sufficient heat dissipation can be ensured. Accordingly, it is possible to provide a semiconductor laser array and an image display device that can keep the semiconductor laser at an operating temperature within a rating.

  Furthermore, according to the present invention, since the semiconductor laser terminal is configured to extend in a direction substantially perpendicular to the emission optical axis direction, the semiconductor laser terminal does not short-circuit with the external heat sink structure. As a result, the two-dimensional position of the semiconductor laser can be adjusted in the direction perpendicular to the optical axis of the collimator lens of the emitted light.

  Further, according to the present invention, since the semiconductor laser terminals are configured to be aerial wired in series, the wiring in the external heat sink structure is reduced, the heat transfer of the external heat sink structure is improved, and the semiconductor laser is rated. Made it possible to keep the operating temperature within.

1 is a cross-sectional view showing a configuration of a semiconductor laser array according to Example 1. FIG. It is sectional drawing which shows the structural example of the conventional semiconductor laser array. FIG. 6 is a configuration diagram illustrating an image display apparatus according to a second embodiment. 6 is a top view showing a configuration of a semiconductor laser according to Example 3. FIG. FIG. 6 is a front view illustrating a configuration of a semiconductor laser according to Example 3.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a configuration of a semiconductor laser array according to Embodiment 1 of the present invention. The semiconductor laser array 1 includes a plurality of blue semiconductor laser chips 2, 3, and 4 that emit blue laser light. Hereinafter, a blue semiconductor laser is abbreviated as B-LD (or simply LD), and blue is abbreviated as B. The semiconductor laser array is also abbreviated as LD array. In the example of FIG. 1, for simplicity, a configuration in which three LD chips 2, 3, and 4 are mounted is shown. Practically, as described above, for example, a total of 26 LD chips are arranged in 5 rows and 6 columns at a pitch of 10 mm or more.

  Corresponding collimating lenses 5, 6 and 7 are arranged on the emission sides of the B-LD chips 2, 3 and 4, respectively. Each B light emitted from the LD chips 2, 3, 4 is converted into parallel light by the collimating lenses 5, 6, 7.

  Each LD chip 2, 3 and 4 is manufactured by a semiconductor process, and is mounted on each stem 8, 9, 10 which is an internal heat sink structure. The stems 8, 9, and 10 are mounted on a substrate 11 that is a common external heat sink structure. The substrate 11 is bonded to the low temperature surface 12 a of the Peltier element 12. The heat dissipation means 13 is joined to the high temperature surface 12 b of the Peltier element 12.

  The heat generated in each of the LD chips 2, 3, 4 is transferred to the substrate 11 through the stems 8, 9, 10, transferred by the Peltier element 12, and transferred to the heat radiating means 13. The heat radiating means 13 is constituted by a plurality of heat radiating fins 13a, for example. For example, heat is radiated by forced air cooling with a cooling fan (not shown).

  Each stem 8, 9, 10 is provided with LD terminals 8a, 8b, 9a, 9b, 10a, 10b of the LD chips 2, 3, 4, but the emitted light of B light emitted from each LD chip. It was comprised so that it might extend in the substantially perpendicular direction (left-right direction of FIG. 1) with respect to the axial direction (upward direction of FIG. 1, shown by the arrow). Among these, a positive voltage is applied to the LD terminals 8a, 9a and 10a, and a negative voltage is applied to the LD terminals 8b, 9b and 10b. In FIG. 1, the LD terminals 8a, 9a, and 10a are arranged on the upper side, and the LD terminals 8b, 9b, and 10b are arranged on the lower side. However, the arrangement may be reversed.

  Next, a sealing structure 14 is provided so as to surround each LD chip 2, 3, 4, each stem 8, 9, 10 and each LD terminal 8a, 8b, 9a, 9b, 10a, 10b. To be installed. On the upper side of the sealed structure 14, openings 15, 16 and 17 through which the respective B lights emitted from the LD chips 2, 3 and 4 pass are formed. A transparent translucent cover glass 18, 19, 20 is attached to each opening 15, 16, 17. That is, in this embodiment, instead of the conventional CAN that individually seals each LD chip (each stem), these are surrounded by a common sealed structure 14 (sealed space 14a).

  The LD terminal 8b of the LD chip 2 and the LD terminal 9a of the LD chip 3 are wired in the air in the sealed space 14a. Similarly, the LD terminal 9b of the LD chip 3 and the LD terminal 10a of the LD chip 4 are also wired in the air in the sealed space 14a. The LD terminal 8a of the LD chip 2 located on the leftmost side is wired in the air in the sealed space 14a to the substrate terminal 11a of the substrate 11. Similarly, the LD terminal 10b of the LD chip 4 located on the rightmost side is aerial wired to the substrate terminal 11b of the substrate 11 in the sealed space 14a. A positive voltage is applied to the substrate terminal 11a, a negative voltage is applied to the substrate terminal 11b, and direct current is applied between the substrate terminals 11a and 11b, so that the LD chips 2, 3, and 4 connected in series are simultaneously emitted. Can be made.

The configuration of the first embodiment will be compared with a configuration using a conventional CAN package.
FIG. 2 is a cross-sectional view showing a configuration example of a semiconductor laser array when a conventional CAN package is used for comparison. A configuration similar to that of FIG. 1 will be briefly described. The semiconductor laser array (LD array) 51 includes a plurality (three) of B-LD chips 52, 53 and 54. By arranging the collimating lenses 55, 56, and 57 corresponding to the LD chips 52, 53, and 54, the B lights emitted from the LD chips 52, 53, and 54 are converted into parallel lights.

  Each LD chip 52, 53, 54 is manufactured by a semiconductor process, and is mounted on each stem 58, 59, 60 which is an internal heat sink structure. Each stem 58, 59, 60 is mounted on a substrate 61 having a common external heat sink structure via a corresponding flange 58f, 59f, 60f. The substrate 61 is bonded to the low temperature surface 62 a of the Peltier element 62, and the heat dissipation means 63 is bonded to the high temperature surface 62 b of the Peltier element 12.

  The heat generated in the LD chips 52, 53, 54 is transferred to the substrate 61 through the stems 58, 59, 60 and the flanges 58 f, 59 f, 60 f, transferred by the Peltier element 62, and transferred to the heat dissipation means 63. heat. The heat dissipating means 63 is composed of a plurality of heat dissipating fins 63a and dissipates heat by forced air cooling with a cooling fan (not shown).

  Each flange 58f, 59f, 60f is provided with LD terminals 58a, 58b, 59a, 59b, 60a, 60b of the LD chips 52, 53, 54. It is configured to be parallel to the upward direction (indicated by an arrow) and extend to the opposite side of the traveling direction of the emitted light.

  Next, a sealed structure CAN 58c surrounding the LD chip 52 and the stem 58 is mounted on the flange 58f. Similarly, a sealed CAN 59c surrounding the LD chip 53 and the stem 59 is mounted on the flange 59f, and a sealed CAN 60c surrounding the LD chip 54 and the stem 60 is mounted on the flange 60f. An opening 65 through which the B light emitted from the LD chip 52 passes is formed above the CAN 58 c, and a sealing light-transmitting cover glass 68 is attached to the opening 65. Similarly, an opening 66 and a translucent cover glass 69 are provided on the upper side of the CAN 59c, and an opening 67 and a translucent cover glass 70 are provided on the upper side of the CAN 60c.

The LD terminal 58 b of the LD chip 52 and the LD terminal 59 a of the LD chip 53 are wired with a space in the substrate 61. Similarly, the LD terminal 59 b of the LD chip 53 and the LD terminal 60 a of the LD chip 54 are wired with a space in the substrate 61. Further, the LD terminal 58 a of the LD chip 52 is wired to the substrate terminal 61 a with a space in the substrate 61. Similarly, the LD terminal 60 b of the LD chip 54 is wired to the substrate terminal 61 b with a space in the substrate 61.
When a positive voltage is applied to the substrate terminal 61a and a negative voltage is applied to the substrate terminal 61b, and direct current is applied between the substrate terminals 61a and 61b, the LD chips 52, 53, and 54 connected in series emit light simultaneously. .

  When the configuration of the first embodiment (FIG. 1) is compared with the conventional configuration (FIG. 2), there are the following differences.

  Comparing the lateral width w1 of the stem 8 in the first embodiment with the lateral width w2 of the conventional stem 58, it is apparent that the lateral width w1 of the first embodiment is larger than the conventional lateral width w2 (w1> w2). 1 and 2 show the shape only in the horizontal direction, the same applies to the depth direction, and the depth of the stem 8 of the first embodiment is larger than the depth of the conventional stem 58. Therefore, the relationship that the cross-sectional area of the stem 8 is larger than the cross-sectional area of the stem 58 is established.

  That is, in the first embodiment, the stems 8, 9, and 10 which are the internal heat sink structures on which the LD chips 2, 3 and 4 manufactured by the semiconductor process are mounted are mounted on the substrate 11 which is the external heat sink structure and Instead of the CANs 58c, 59c and 60c, a common sealed structure 14 surrounding the plurality of LD chips 2, 3 and 4 is used. As a result, the cross-sectional area of the stems 8, 9, and 10 on which the LD chips 2, 3, and 4 are mounted can be increased without being restricted by the CAN. The heat transfer to the substrate 11 is improved, and the heat dissipation can be greatly improved. As a result, it is possible to realize a semiconductor laser array that can keep the semiconductor laser at an operating temperature within the rated range.

  Further, as is apparent from FIG. 1, if the stem width w1 that can ensure practically sufficient heat dissipation is determined, a margin is generated in the interval between adjacent stems. For this reason, the pitch p1 of the B-LDs 2, 3 and 4 can be reduced to 10 mm or less. Therefore, there is an effect that the LD light source device can be downsized by reducing the size of the LD array in the row direction and the column direction.

  Further, in the conventional configuration, each of the LD terminals 58a, 58b, 59a, 59b, 60a, and 60b is configured to extend in parallel with the outgoing optical axis direction, whereas the LD terminals 8a, 8b, 9a, and 9b in the first embodiment. , 10a, 10b are configured to extend in a direction substantially perpendicular to the outgoing optical axis direction. Therefore, each LD terminal does not short-circuit with the substrate 11 which is an external heat sink structure. This makes it possible to adjust the two-dimensional position of the LD chips 2, 3, 4 in the direction perpendicular to the optical axes of the collimating lenses 5, 6, 7 without impairing heat dissipation from the stem to the substrate. Since the LD chips 2, 3 and 4 can be two-dimensionally adjusted in the direction perpendicular to the optical axis, the collimating lenses 5, 6, and 7 need only be adjusted one-dimensionally in the optical axis direction. Therefore, the LD chips 2, 3, 4 and the collimating lenses 5, 6, 7 can be relatively adjusted in three-dimensional position, and both heat dissipation and a position adjusting function can be achieved.

  Further, in the conventional configuration, in addition to the two wirings of the left terminal 61a and the right terminal 61b in the substrate 61, there are a total of four wirings connecting the terminal 58b and the terminal 59a and wiring connecting the terminal 59b and the terminal 60a. There were two wires. On the other hand, in the first embodiment, since a plurality of LD terminals are connected in series in the air, the board 11 has only two wirings of the left terminal 11a and the right terminal 11b. Can be reduced by two. That is, according to the first embodiment, an LD array is provided that improves the heat transfer of the substrate 11 by reducing the wiring in the substrate 11 which is an external heat sink structure, and can keep the LD at an operating temperature within the rating. it can.

  In the second embodiment, an example in which the semiconductor laser array 1 described in the first embodiment is applied to an image display device will be described.

  FIG. 3 is a configuration diagram illustrating an image display apparatus according to the second embodiment. The image display device includes a B-LD light source unit 35, an integrator 34, an image display element (DMD) 40, a projection lens unit 41, and the like. The B-LD array 1 included in the B-LD light source unit 35 corresponds to the semiconductor laser array 1 in FIG. First, the configuration of the B-LD light source unit 35 will be described.

  The B light beam 21 emitted from the B-LD array 1 and made substantially parallel light enters the dichroic mirror 26 via a convex lens 22, a concave lens 23, and multi-lens arrays (MLAs) 24 and 25. The dichroic mirror 26 has a spectral transmission reflectance characteristic that reflects B light, transmits green (G) light, transmits yellow (Y) light, and transmits red (R) light. Hereinafter, green is abbreviated as G, yellow as Y, and red as R.

  The B light reflected by the dichroic mirror 26 is refracted by the lenses 27 and 28, condensed into a substantially rectangular shape, and enters the phosphor wheel 29. Here, the reason why the light is condensed into a substantially rectangular shape is that each lens opening of the MLA 24 has a rectangular shape and is configured to form an image on the phosphor wheel 29 by the MLA 25 and the lenses 27 and 28. The lenses 27 and 28 have a common lens optical axis, and the B light is configured so as to pass through a substantially half of the lens optical axis on the lower side in the drawing. In other words, the dichroic mirror 26 is disposed so as to be substantially halfway below the lens optical axis (in the depth direction of the drawing sheet).

  The phosphor wheel 29 includes a B light specular reflection part 29B, a G phosphor reflection part 29G, an R phosphor reflection part 29R, and a Y phosphor reflection part 29Y in the circumferential direction. The reflection part where the B light is incident is switched by the division. FIG. 3 illustrates the moment when the B light is incident on the B light mirror reflection portion 29B.

  The B light is specularly reflected by the B light specular reflection unit 29B. The B reflected light travels with the half of the lens optical axis on the upper side of the drawing (frontward in the drawing), refracts the lenses 28 and 27 and returns to substantially parallel light, passes through the sky part without the dichroic mirror 26, The light is condensed into a substantially rectangular shape via the lens 31 and enters the color wheel 32. Here, the reason why the light is focused in a substantially rectangular shape is that the light imaged on the phosphor wheel 29 has a substantially rectangular shape and is formed on the color wheel 32 by the lenses 28, 27, and 31. It is.

  The color wheel 32 is provided with a B light diffusing and transmitting surface 32B and a GRY light transmitting and B light reflecting surface 32A in the circumferential direction. Switch in sync with wheel 29. The B light that has passed through the B light diffusing and transmitting surface 32 </ b> B of the color wheel 32 enters the integrator 34.

  Next, a case where B light is incident on the G phosphor reflecting portion 29G of the phosphor wheel 29 will be described. The G light excited by the G phosphor reflector 29G is diffusely reflected by the B light. The half of the G optical axis on the lower side of the optical axis of the lens (in the depth direction of the drawing paper) is refracted by the lenses 28 and 27 to become substantially parallel light, passes through the dichroic mirror 26, and passes through the lens 31 and the color wheel. Then, the light enters the integrator 34 via 32. About half of the G reflected light on the upper side of the drawing (the front side in the drawing) is refracted by the lenses 28 and 27 to become substantially parallel light, passes through the sky part without the dichroic mirror 26, and passes through the lens 31 and the color wheel 32. The light enters the integrator 34 through the GRY light transmitting and B light reflecting surface 32A.

  Next, a case where the B light is incident on the R phosphor reflecting portion 29R of the phosphor wheel 29 will be described. The R light excited by the R phosphor reflecting portion 29R is diffusely reflected by the B light. Of the R reflected light, the lower half of the optical axis of the lens in the drawing (the depth direction in the drawing paper) is refracted by the lenses 28 and 27 to become substantially parallel light, passes through the dichroic mirror 26, and passes through the lens 31 and the color wheel. 32 enters the integrator 34 through the GRY light transmitting and B light reflecting surface 32A. About half of the R optical axis on the upper side of the optical axis of the lens (front side in the drawing) is refracted by the lenses 28 and 27 to become substantially parallel light, and passes through the sky part where the dichroic mirror 26 is not provided. The color wheel 32 enters the integrator 34 through the GRY light transmitting and B light reflecting surface 32A.

Next, the case where the B light is incident on the Y phosphor reflecting portion 29Y of the phosphor wheel 29 will be described. The Y light excited by the Y phosphor reflector 29Y is diffusely reflected by the B light. Nearly half of the Y optical axis of the lens optical axis in the drawing (in the depth direction of the drawing paper) is refracted by the lenses 28 and 27 to become substantially parallel light, passes through the dichroic mirror 8, and passes through the lens 31 and the color wheel. 32 enters the integrator 34 through the GRY light transmitting and B light reflecting surface 32A. Nearly half of the Y optical axis of the lens optical axis in the drawing (the front side of the drawing) is refracted by the lenses 28 and 27 to become substantially parallel light, passes through the sky part without the dichroic mirror 26, and passes through the lens 31, The color wheel 32 enters the integrator 34 through the GRY light transmitting and B light reflecting surface 32A.
As described above, the B reflected light, the G reflected light, the R reflected light, and the Y reflected light are merged, and are guided from the B-LD light source unit 35 to the integrator 34 as illumination light.

  Next, the configuration after the integrator 34 will be described. The illumination light whose illuminance distribution is made uniform by the integrator 34 enters the DMD 40 via the lenses 36 and 37, the mirror 38, and the lens 39. The DMD 40 is a kind of image display element, and is a digital micromirror device developed by Texas Instruments. The image light modulated and reflected by the DMD 40 according to the image signal is incident on the projection lens unit 41 via the lens 39. The projection lens unit 41 enlarges and projects the modulated image light onto a screen (not shown).

  According to the second embodiment, since the LD array that makes it possible to keep the LD at an operating temperature within the rating is used, an image display device that can always display a bright image is provided.

  In addition, each of the LD chips 2, 3, 4 and the collimating lenses 5, 6, 7 can be relatively adjusted in the B-LD array 1 so that both the optical axis position adjustment and the heat radiation can be performed. The light beam group emitted from the LD array 1 can be made substantially parallel light. Therefore, the rectangular spot condensed on the phosphor wheel 29 via the convex lens 22, the concave lens 23, the multi-lens array (MLA) 24, 25, the dichroic mirror 26, and the lenses 27, 28 is ideal as the optical design. Can be sized.

  Since the optical axis cannot be adjusted in the conventional LD of the CAN package, the optical axis of each light beam group is shifted, the rectangular spot is blurred and enlarged, and the etendue is increased. When the etendue increases, the phosphor wheel 29, lenses 28 and 27, dichroic mirror 26, lens 31, color wheel 32, integrator 34, lenses 36 and 37, mirror 38, lens 39, DMD 40, lens 39, and projection lens unit 41 are reached. The light utilization efficiency was lowered at each aperture of the optical path. On the other hand, the LD according to the second embodiment has an effect that it is possible to provide a bright image display device because the optical axis can be adjusted and the light use efficiency does not decrease.

  In addition, according to the second embodiment, since the plurality of LD terminals are connected in series in the air, the wiring in the substrate 11 that is the external heat sink structure is reduced, and the heat transfer of the substrate 11 is improved. Since an LD array having a configuration capable of keeping the LD within the rated operating temperature can be used, sufficient heat dissipation can be secured and a bright image display device can be provided.

  In the second embodiment, the example in which the LD array according to the first embodiment is applied to the image display device has been described. However, it is needless to say that the present invention is not limited to this and can be applied to other optical devices.

  In the first embodiment, the case of an LD array composed of a plurality of semiconductor lasers (LDs) has been described. However, the present invention is not limited to this and can be applied to the case of a single LD. That is, the configuration in which the LD terminal is arranged so as to extend in a direction substantially perpendicular to the LD emission optical axis direction is also effective in the case of a single LD, and this case will be described in a third embodiment.

  4 and 5 show the configuration of the semiconductor laser according to Example 3. FIG. 4 is a top view thereof, and FIG. 5 is a front view thereof. The semiconductor laser (LD) 81 includes a single semiconductor laser chip (LD chip) 82 serving as a laser emission source.

  The LD chip 82 is manufactured by a semiconductor process and is mounted on a stem 83 having an internal heat sink structure. Furthermore, the stem 83 is mounted on the flange 83f. Note that the stem 83 and the flange 83f may be integrally formed. In the flange 83f, the LD terminals 83a and 83b of the LD chip 82 are configured to extend in a direction substantially perpendicular to the laser beam emission optical axis direction (in-plane direction in FIG. 4 and lateral direction in FIG. 5). .

  A CAN 83c, which is a sealed structure surrounding the LD chip 82 and the stem 83, is mounted on the flange 83f. An opening 84 through which laser light emitted from the LD chip 82 passes is formed on the upper side of the CAN 83 c, and a sealing translucent cover glass 85 is attached to the opening 84.

  As described above, in the semiconductor laser of Example 3, the CAN, which is a sealed structure, is mounted on the flange of the stem on which one LD chip is mounted, and extends in a direction substantially perpendicular to the laser emission optical axis direction in the flange. This constitutes an LD terminal. This structure is obtained by changing the direction of the LD terminal arranged on the flange portion of the conventional CAN package, and can also be applied to the CAN type.

  According to the third embodiment, since there is no LD terminal on the back surface 83d of the flange, it can be easily attached to a substrate which is an external heat sink structure (not shown). Further, heat transfer to the external heat sink structure is improved, and sufficient heat dissipation can be ensured. Furthermore, it is possible to adjust the two-dimensional position of the LD 81 in the direction perpendicular to the direction of the outgoing optical axis without causing the LD terminal to short-circuit with the external heat sink structure.

  The LD terminals 83a and 83b are arranged so as to be inclined by + 45 ° with respect to the mounting direction of the LD chip 82 (the horizontal direction in FIG. 4 and the horizontal direction in FIG. 5). Further, the holding grooves 86 and 87 of the flange 83f are arranged so as to be inclined by −45 ° with respect to the mounting direction of the LD chip 82. By arranging them with an inclination of ± 45 ° in this way, the LD interval can be narrowed when the LDs 81 are arranged in an array in the row and column directions, so that the dimensions in the row and column directions become smaller. The light source device can be downsized.

  The semiconductor laser according to the third embodiment can be widely applied to an optical device such as an optical pickup for a recordable optical disc that requires heat dissipation with a high-power LD and needs to be adjusted relative to a collimating lens. it can.

  DESCRIPTION OF SYMBOLS 1 ... Semiconductor laser array (LD array), 2, 3, 4 ... Blue semiconductor laser chip (B-LD chip), 5, 6, 7 ... Collimating lens, 8, 9, 10 ... Stem, 8a, 8b, 9a, 9b, 10a, 10b ... LD terminal, 11 ... substrate, 11a, 11b ... substrate terminal, 12 ... Peltier element, 12a ... low temperature surface, 12b ... high temperature surface, 13 ... heat dissipation means, 13a ... heat dissipation fin, 14 ... sealed structure , 14a ... sealed space, 15, 16, 17 ... opening, 18, 19, 20 ... translucent cover glass, 21 ... B ray bundle, 22 ... convex lens, 23 ... concave lens, 24, 25 ... MLA, 26 ... dichroic Mirror, 27, 28 ... Lens, 29 ... Phosphor wheel, 29B ... B light reflector, 29G ... G phosphor reflector, 29R ... R phosphor reflector, 29Y ... Y phosphor reflector, 30 ... Motor DESCRIPTION OF SYMBOLS 31 ... Lens, 32 ... Color wheel, 32a ... GRY light transmission and B reflection surface, 32b ... B light diffusion transmission surface, 33 ... Motor, 34 ... Integrator, 35 ... B-LD light source part, 36, 37 ... Lens, 38 Mirror, 39 ... Lens, 40 ... DMD, 41 ... Projection lens unit, 81 ... Semiconductor laser (LD), 82 ... LD chip, 83 ... Stem, 83a, 83b ... LD terminal, 83c ... CAN (sealed structure), 83f ... flange, 83d ... back surface of the flange, 84 ... opening, 85 ... translucent cover glass, 86, 87 ... holding groove, p1 ... pitch, wl ... stem width.

Claims (8)

A plurality of semiconductor laser chips manufactured by a semiconductor process and emitting a predetermined laser beam;
A plurality of stems that are internal heat sink structures each mounting the plurality of semiconductor laser chips;
A common external heat sink structure mounting the plurality of stems;
A common sealed structure that is mounted on the external heat sink structure and surrounds the plurality of stems on which the plurality of semiconductor laser chips are mounted;
A semiconductor laser array comprising: A plurality of semiconductor laser chips manufactured by a semiconductor process and emitting a predetermined laser beam;
A plurality of stems that are internal heat sink structures each mounting the plurality of semiconductor laser chips;
A common external heat sink structure for mounting the plurality of stems,
A plurality of semiconductor laser terminals of the plurality of semiconductor laser chips are configured on each stem so as to extend in a direction substantially perpendicular to the direction of the optical axis emitted from each semiconductor laser chip. array. The semiconductor laser array according to claim 1, wherein
A plurality of semiconductor laser terminals of the plurality of semiconductor laser chips are configured on each stem so as to extend in a direction substantially perpendicular to the direction of the optical axis emitted from each semiconductor laser chip. array. The semiconductor laser array according to claim 2 or 3,
A semiconductor laser array, wherein a plurality of semiconductor laser terminals are connected in series in the air. A semiconductor laser chip manufactured by a semiconductor process and emitting a predetermined laser beam;
A stem that is an internal heat sink structure on which the semiconductor laser chip is mounted;
A flange mounted with the stem and joined to an external heat sink structure;
A sealed structure that is mounted on the flange and surrounds the stem on which the semiconductor laser chip is mounted,
A semiconductor laser characterized in that a semiconductor laser terminal of the semiconductor laser chip is configured in the flange so as to extend in a direction substantially perpendicular to the direction of an optical axis emitted from the semiconductor laser chip. The semiconductor laser according to claim 5, wherein
2. A semiconductor laser according to claim 1, wherein the semiconductor laser terminal is disposed at an angle of approximately 45.degree. With respect to the mounting direction of the semiconductor laser chip. The semiconductor laser according to claim 6, wherein
The semiconductor laser according to claim 1, wherein the holding groove of the flange is disposed at an angle of approximately 45 ° on the side opposite to the semiconductor laser terminal with respect to the mounting direction of the semiconductor laser chip. A light source unit including the semiconductor laser array according to any one of claims 1 to 4,
An image display element that modulates illumination light output from the light source unit according to an image signal;
A projection unit for enlarging and projecting the modulated image light;
An image display device comprising:

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