WO2022244440A1

WO2022244440A1 - Optical module and optical module system

Info

Publication number: WO2022244440A1
Application number: PCT/JP2022/012493
Authority: WO
Inventors: 勇貴中村; 将人古川; 麻子山田; 孝史京野
Original assignee: 住友電気工業株式会社
Priority date: 2021-05-18
Filing date: 2022-03-18
Publication date: 2022-11-24
Also published as: JPWO2022244440A1

Abstract

This optical module comprises a support plate and an electron cooling module. The electron cooling module has a heat dissipation plate placed on a first main surface of the support plate, a heat absorption plate, and a plurality of semiconductor pillars connecting the heat dissipation plate and the heat absorption plate. The optical module comprises at least one laser diode attached to the heat absorption plate, a first thermistor that detects the temperature of the heat dissipation plate, and a second thermistor that detects the temperature of the heat absorption plate.

Description

Optical modules and optical module systems

The present disclosure relates to optical modules and optical module systems. This application claims priority based on Japanese application No. 2021-083621 filed on May 18, 2021, and incorporates all the descriptions described in the Japanese application.

　Optical modules are sometimes used in environments with a wide temperature range from low to high. An electronic cooling module is sometimes used to adjust the temperature of the members that constitute the optical module (see, for example, Patent Document 1).

JP 2016-134416 A

The optical module of the present disclosure includes a support plate and an electronic cooling module. The electronic cooling module has a heat sink disposed on the first main surface of the support plate, a heat absorbing plate, and a plurality of semiconductor columns connecting the heat sink and the heat absorbing plate. The optical module includes at least one laser diode attached to the heat absorbing plate, a first thermistor detecting the temperature of the heat absorbing plate, and a second thermistor detecting the temperature of the heat absorbing plate.

FIG. 1 is an external perspective view showing the structure of an optical module according to Embodiment 1. FIG. FIG. 2 is an external perspective view of the optical module shown in FIG. 1 with a cap described later removed. 3 is a schematic plan view of the optical module shown in FIG. 2. FIG. FIG. 4 is a schematic perspective view of an optical module system according to Embodiment 2. FIG. FIG. 5 is a block diagram schematically showing the system configuration of the optical module system according to the second embodiment. FIG. 6 is an external perspective view showing the structure of an optical module according to Embodiment 3. FIG. 7 is an external perspective view showing a state in which the cap of the optical module shown in FIG. 6 is removed. FIG. 8 is a schematic plan view of the optical module shown in FIG. 7. FIG. FIG. 9 is a schematic plan view of an optical module according to Embodiment 4. FIG. FIG. 10 is a schematic perspective view of an optical module system according to Embodiment 5. FIG. FIG. 11 is a block diagram schematically showing the system configuration of the optical module system according to the fifth embodiment.

[Problems to be Solved by the Present Disclosure]
An optical module is required to stabilize the output of light emitted from a laser diode.
Accordingly, one object of the present disclosure is to provide an optical module capable of stabilizing the output of emitted light.

[Effect of the present disclosure]
According to the above optical module, it is possible to stabilize the output of emitted light.

[Description of Embodiments of the Present Disclosure]
First, the embodiments of the present disclosure are listed and described. An optical module according to the present disclosure includes a support plate and an electronic cooling module. The electronic cooling module has a heat sink disposed on the first main surface of the support plate, a heat absorbing plate, and a plurality of semiconductor columns connecting the heat sink and the heat absorbing plate. The optical module includes at least one laser diode attached to the heat absorbing plate, a first thermistor detecting the temperature of the heat absorbing plate, and a second thermistor detecting the temperature of the heat absorbing plate.

In optical modules, the stability of the output of light emitted from laser diodes is required. In laser diodes, the output of emitted light changes with changes in temperature. Also, the laser diode itself generates heat by emitting light. Therefore, in order to stabilize the output of emitted light, it is preferable to keep the temperature constant in the laser diode. It is conceivable to keep the temperature of the laser diode constant by placing the laser diode on an electronic cooling module whose temperature can be adjusted by controlling the current based on the sensed temperature of the laser diode.

Here, an image may be drawn by projecting an image with light emitted from a laser diode. In such a case, the inventors have found that an electronic cooling module that detects the temperature of the laser diode and adjusts the temperature of the laser diode based on the detected temperature of the laser diode strictly adjusts the temperature of the laser diode. We focused on the fact that it is difficult to In adjusting the temperature by the electronic cooling module, the temperature change of the thermistor arranged near the laser diode is read by the change in electrical resistance. Then, this temperature change is fed back, and the amount of current supplied to the electronic cooling module is adjusted so that the laser diode reaches the target temperature, heat is absorbed, and the temperature is adjusted. However, in such a configuration, the thermal resistance between the laser diode and the thermistor will delay the reading of the temperature change. In addition, due to the thermal resistance between the laser diode and the electronic cooling module, it is difficult to strictly adjust the temperature in accordance with temperature changes. In particular, when an image is projected to draw an image, the current supplied to the laser diode is switched on and off in a short period of time. As a result, the amount of heat generated by the laser diode changes rapidly in a short period of time. Here, if the amount of current supplied to the thermoelectric cooling module is adjusted so that the laser diode reaches the target temperature, the amount of current directly depends on the temperature read, so overshoot and ringing will occur in the laser diode temperature. more likely to occur. The present inventors have focused on the fact that it is difficult to adjust the temperature of the laser diode by the electronic cooling module, and that appropriate drawing is difficult.

Therefore, the present inventors have made intensive studies and have come up with the idea of adjusting the temperature of the laser diode by appropriately following the temperature change of the laser diode. Then, if the exact temperature of the heat absorbing plate and the heat sink in the electronic cooling module can be grasped, the current supplied to the electronic cooling module can be appropriately adjusted, and the temperature of the laser diode can be kept constant. has come to constitute

The optical module according to the present disclosure includes the first thermistor that detects the temperature of the heat sink and the second thermistor that detects the temperature of the heat sink. Then, in the electronic cooling module, the temperature of the radiator plate and the temperature of the heat absorbing plate can be accurately grasped. When drawing with light in the optical module, information on the timing and amount of light emitted from the laser diode (information on light emission from the laser diode) is obtained in advance, so the amount of heat generated by the laser diode is calculated. Then, based on the calculated amount of heat generated, the temperature of the radiator plate, and the temperature of the heat absorption plate, the current supply to the electronic cooling module is controlled. Then, it becomes easy to keep the temperature of the laser diode constant by suppressing overshoot and ringing, and the output of emitted light can be stabilized.

In the above optical module, the first thermistor may be arranged on the first main surface of the support plate. Since the heat sink is bonded to the support plate, the temperature of the heat sink can be detected more accurately by the first thermistor. Therefore, the output of emitted light can be stabilized.

The above optical module may further include a base plate, and the laser diode and the second thermistor may be attached to the heat absorbing plate via the base plate. By doing so, the temperature of the laser diode and the temperature of the radiator plate can be simultaneously detected, and the number of thermistors to be installed can be reduced.

The optical module may further include a third thermistor that detects the temperature of the laser diode. By doing so, the functions can be divided into the second thermistor for detecting the temperature of the heat sink, and the temperature of the heat absorbing plate 32 can be detected more accurately, and furthermore the temperature of the laser diode can be detected and its stability can be improved. can be evaluated. Therefore, it is possible to further stabilize the output of emitted light.

The above optical module may further include a filter that reflects at least part of the light emitted from the laser diode, and the laser diode and the second thermistor may be arranged with the filter interposed therebetween. By doing so, the second thermistor can more accurately detect the temperature of the heat absorbing plate 32 without being affected by the laser diode that is the heat source. Therefore, it is possible to further stabilize the output of emitted light.

In the above optical module, the electronic cooling module may control the supply of current so as to depend on the amount of heat generated by the laser diode calculated from the information for causing the laser diode to emit light. As will be shown later, information on the amount of heat generated can be used to predict the amount of heat absorbed necessary to adjust the laser diode to a constant temperature. Therefore, the electronic cooling module can appropriately adjust the current and stabilize the output of emitted light.

In the above optical module, a plurality of laser diodes may be provided. By doing so, the output of each light emitted from the plurality of laser diodes can be stabilized. In addition, when light emitted from a plurality of laser diodes is combined to emit light of a desired color, since the output of each light is stabilized, color shift can be suppressed.

The above optical module may further include a mirror driving mechanism arranged on the electronic cooling module for scanning the light emitted from the laser diode. The mirror driving mechanism scans the light emitted from the laser diode by periodically swinging a mirror that reflects the light emitted from the laser diode. By including the mirror driving mechanism in the optical module, the light emitted from the laser diode can be scanned and emitted out of the optical module. Then, the optical module can draw using the light emitted from the laser diode. Here, the oscillating motion of the mirror is dependent on temperature, and if the temperature of the mirror drive mechanism is not constant, the swing angle of the mirror will change greatly. Then, the light emitted from the laser diode cannot be properly scanned. According to the above optical module, since the mirror driving mechanism is arranged on the electronic cooling module, it becomes easy to keep the temperature of the mirror driving mechanism constant. By doing so, it is possible to suppress the change in the deflection angle of the mirror depending on the temperature. Therefore, it is possible to emit light that has been scanned with higher accuracy. As a result, drawing by the optical module can be performed appropriately.

The optical module system of the present disclosure includes the optical module described above and a control unit that calculates the amount of heat generated by the laser diode based on information for causing the laser diode to emit light. By doing so, the amount of heat generated by the laser diode, the timing of heat generation, etc. can be grasped in advance, and the amount of heat absorbed corresponding to the amount of heat generated by the laser diode can be predicted to adjust the current supply. be able to. Therefore, it is possible to further stabilize the light output.

In the above optical module system, the control unit controls current supplied to the electronic cooling module based on the calculated amount of heat generated, the temperature detected by the first thermistor, and the temperature detected by the second thermistor. may By doing so, it is possible to use control by the control unit to supply current to the electronic cooling module at appropriate timing and keep the temperature of the laser diode on the electronic cooling module constant. Therefore, it is possible to further stabilize the output of emitted light.

[Details of the embodiment of the present disclosure]
Next, one embodiment of the optical module of the present disclosure will be described with reference to the drawings. In the following drawings, the same reference numerals are given to the same or corresponding parts, and the description thereof will not be repeated.

(Embodiment 1)
An optical module according to Embodiment 1 of the present disclosure will be described. FIG. 1 is an external perspective view showing the structure of an optical module according to Embodiment 1. FIG. FIG. 2 is an external perspective view of the optical module shown in FIG. 1 with a cap described later removed. 3 is a schematic plan view of the optical module shown in FIG. 2. FIG.

1, 2 and 3, an optical module 10a includes a light forming portion 11 that forms light, and a protective member 12 that surrounds the light forming portion 11 and seals the light forming portion 11. . The protective member 12 includes a flat support plate 13 as a base body and a cap 14 as a lid welded to the support plate 13 . The support plate 13 has a rectangular shape when viewed in the thickness direction, and has rounded corners. Specifically, the support plate 13 is configured such that the length in the X-axis direction is longer than the length in the Y-axis direction. The thickness direction of the support plate 13 and the base plate 20, which will be described later, is the direction indicated by the arrow Z. As shown in FIG. The support plate 13 includes a first main surface 13a perpendicular to the Z-axis direction and a second main surface 13b facing the first main surface 13a. The light forming portion 11 is arranged on the first main surface 13a. The cap 14 is arranged in contact with the first main surface 13 a so as to cover the light forming portion 11 . The cap 14 is provided with an emission window 15 made of glass through which the light formed by the light forming section 11 is transmitted. The light forming portion 11 is hermetically sealed with a protective member 12 . A plurality of lead pins 16 penetrate through the support plate 13 from the second main surface 13b side to the first main surface 13a side and protrude to both the first main surface 13a side and the second main surface 13b side. are installed on the support plate 13 .

The light forming portion 11 includes a base plate ₂₀ having a flat plate shape as a base portion, a _first laser diode 41 (red laser diode) emitting red light in the direction indicated by the arrow L1, and an arrow L2. a second laser diode (green laser diode) that emits green light in the direction indicated by arrow L3; a _third laser diode (blue laser diode) that emits blue light in the direction indicated by arrow L3; It includes a second lens 52 , a third lens 53 , a first filter 61 , a second filter 62 and a third filter 63 . That is, in this embodiment, the optical module 10a includes a plurality of laser diodes. Specifically, the optical module 10a includes three laser diodes.

The base plate 20 includes a first principal surface 20a perpendicular to the Z-axis direction and a second principal surface 20b facing the first principal surface 20a. A thick portion 24 on which the first laser diode 41, the second laser diode 42 and the third laser diode 43 are mounted is formed at the end portion of the base plate 20 in the Y-axis direction. A first flat plate submount 26, a second flat plate submount 27, and a third flat plate submount 28 are arranged on the thick portion 24 at intervals in the X direction. . A first laser diode 41 is arranged on the first submount 26 . Thus, the first laser diode 41 is attached to the heat absorbing plate 32 with the base plate 20 and the first submount 26 interposed therebetween. A second laser diode 42 is arranged on the second submount 27 . Thus, the second laser diode 42 is attached to the heat absorbing plate 32 with the base plate 20 and the second submount 27 interposed therebetween. A third laser diode 43 is arranged on the third submount 28 . Thus, the third laser diode 43 is attached to the heat absorbing plate 32 with the base plate 20 and the third submount 28 interposed therebetween. The first laser diode 41, the second laser diode 42, and the third laser diode 43 are arranged to emit light in the Y-axis direction.

A first lens 51, a second lens 52 and a third lens 53 for converting the spot size of light are arranged side by side in the X direction on the first main surface 20a of the base plate 20, respectively. The first lens 51, the second lens 52 and the third lens 53 convert the spot size of the light emitted from the first laser diode 41, the second laser diode 42 and the third laser diode 43 respectively. The light emitted from the first laser diode 41, the second laser diode 42 and the third laser diode 43 are converted into collimated light by the first lens 51, the second lens 52 and the third lens 53, respectively.

A first filter 61, a second filter 62, and a third filter 63 are arranged side by side on the first main surface 20a of the base plate 20 with a gap therebetween in the X direction. The first filter 61, the second filter 62, and the third filter 63 are arranged so that their reflecting surfaces are inclined 45 degrees with respect to the X direction and the Y direction when viewed in the thickness direction of the support plate 13. .
The first filter 61 reflects red light emitted from the first laser diode 41 . The second filter 62 transmits the red light reflected by the first filter 61 and reflects the green light emitted from the second laser diode 42 . The third filter 63 transmits red light reflected by the first filter 61 and transmitted through the second filter 62 , transmits green light reflected by the second filter 62 , and is emitted from the third laser diode 43 . reflect blue light. Thus, the first filter 61, the second filter 62 and the third filter 63 selectively transmit and reflect light of specific wavelengths. As a result, the first filter 61 , the second filter 62 and the third filter 63 combine the lights emitted from the first laser diode 41 , the second laser diode 42 and the third laser diode 43 . The multiplexed light travels along the direction indicated by arrow _L4 and is emitted from the exit window 15 to the outside of the optical module 10a.

The optical module 10 a includes an electronic cooling module 30 . The electronic cooling module 30 adjusts the temperatures of the first laser diode 41 , the second laser diode 42 and the third laser diode 43 . The electronic cooling module 30 is also called a TEC (Thermo-Electric Cooler) and includes a radiator plate 31 , a heat absorption plate 32 and a plurality of semiconductor columns 33 . The electronic cooling module 30 is arranged between the support plate 13 and the base plate 20 . The heat sink 31 is arranged on the first main surface 13 a of the support plate 13 . The heat absorbing plate 32 is arranged on the second main surface 20 b of the base plate 20 . That is, the base plate 20 is arranged on the heat absorbing plate 32 . The support plate 13 and the heat radiation plate 31, and the base plate 20 and the heat absorption plate 32 are respectively bonded with a bonding material (not shown). The plurality of semiconductor pillars 33 are composed of Peltier elements, and are arranged side by side at intervals in the X direction and the Y direction, respectively, between the radiator plate 31 and the heat absorption plate 32 . A plurality of semiconductor columns 33 are connected to the radiator plate 31 and the heat absorbing plate 32 . By energizing the electronic cooling module 30, the temperature of the members attached to the heat absorption plate 32 of the electronic cooling module 30, which is the first laser diode 41, the second laser diode 42 and the third laser diode 43 in this embodiment, is adjusted. can do. By adjusting the current supplied to the electronic cooling module 30, it becomes easy to keep the temperature of the member attached to the heat absorbing plate 32 constant over a long period of time, specifically at 35° C., for example.

The optical module 10 a includes a first thermistor 34 that detects the temperature of the radiator plate 31 . The first thermistor 34 is arranged on the first main surface 13 a of the support plate 13 . The first thermistor 34 may have a pedestal 25 between it and the support plate 13 . The pedestal 25 is preferably made of a material having a high thermal conductivity, such as aluminum nitride (AlN). The first thermistor 34 is arranged adjacent to the radiator plate 31 within a distance of 3 mm when viewed in the Z-axis direction. By arranging in this way, the first thermistor 34 can detect substantially the same temperature as the temperature of the radiator plate 31 . Note that the first thermistor 34 may be arranged on the heat sink 31 .

The optical module 10 a also includes a second thermistor 35 that detects the temperature of the heat absorbing plate 32 . The second thermistor 35 is attached to the heat absorbing plate 32 with the base plate 20 interposed therebetween. The base plate 20 is preferably made of a material with high thermal conductivity, such as aluminum nitride (AlN). Specifically, the second thermistor 35 is arranged on the thick portion 24 . By arranging in this way, the second thermistor 35 can detect substantially the same temperature as the temperature of the heat absorbing plate 32 .

According to the optical module 10a, the first thermistor 34 for detecting the temperature of the heat sink 31 and the second thermistor 35 for detecting the temperature of the heat absorbing plate 32 are provided. Then, in the electronic cooling module 30, the temperatures of the radiator plate 31 and the heat absorbing plate 32 can be accurately grasped. When drawing with light in the optical module 10a, information on the timing and amount of light emitted from the first laser diode 41, the second laser diode 42, and the third laser diode 43 (information on which the laser diodes emit light) is obtained in advance. Therefore, the heat quantity Qh generated by the first laser diode 41, the second laser diode 42 and the third laser diode 43 is calculated. From information on the calculated amount of heat generated Qh, it is possible to predict the amount of heat absorbed Qc required to adjust the temperatures of the first laser diode 41, the second laser diode 42 and the third laser diode 43 to a constant temperature.

The heat absorption amount Qc absorbed by the electronic cooling module 30 is calculated from the current value of the electronic cooling module 30, the temperature of the radiator plate 31, and the temperature of the heat absorption plate 32. For example, Formula 1 below. In Equation 1, Qc is the amount of heat absorbed, α is the Seebeck coefficient, Tc is the temperature of the heat absorbing plate 32, I is the current, R is the internal electrical resistance of the semiconductor pillar 33, Kpp is the thermal conductance inside the semiconductor pillar 33, and Th is the heat dissipation. is the temperature of the plate 31; From this equation, the current value can be obtained by taking the value obtained by adding the inflow heat quantity Qair from the outside to the heat quantity Qh calculated above as the heat absorption quantity Qc. The inflow heat amount Qair is the amount of heat that flows into the heat absorbing plate 32 from the atmosphere in the protective member 12 based on the temperature difference between the heat absorbing plates 32, and is obtained from the temperature Th of the heat absorbing plate 32 and the ambient temperature Ta. If the inflow heat amount Qair is sufficiently smaller than the heat generation amount Qh (for example, 1/10 or less), it may be ignored in the calculation of the current value. As described above, the electronic cooling module 30 controls the current supply so as to depend on the amount of heat generated by the laser diode Qh calculated from the information for causing the laser diode to emit light. Specifically, the current supplied to the electronic cooling module 30 can be adjusted based on the information for causing the laser diode to emit light, the temperature of the radiator plate 31 , and the temperature of the heat absorption plate 32 . This adjustment facilitates keeping the temperatures of the first laser diode 41, the second laser diode 42, and the third laser diode 43 constant, and stabilizes the output of emitted light. Note that the amount of current may be adjusted in consideration of the heat transfer time lag (greater than 0 ms and within 100 ms) obtained based on transient thermal analysis performed in advance and actual measurement results of heat conduction.

In this embodiment, the optical module 10a includes a first laser diode 41 that emits red light, a second laser diode 42 that emits green light, and a third laser diode 43 that emits blue light. Also, the positions of the laser diodes of each color can be exchanged with each other. That is, the optical module 10a includes multiple laser diodes. Therefore, the output of each light emitted from the first laser diode 41, the second laser diode 42 and the third laser diode 43 can be stabilized. In addition, when light emitted from a plurality of laser diodes is combined to emit light of a desired color, since the output of each light is stabilized, color shift can be suppressed.

In the present embodiment, the first thermistor 34 is arranged on the first principal surface 13a of the support plate 13 . Since the heat sink 31 is joined to the support plate 13 , the temperature of the heat sink 31 can be detected more accurately by the first thermistor 34 . Therefore, the output of emitted light can be stabilized.

(Embodiment 2)
Next, Embodiment 2, which is another embodiment, will be described. FIG. 4 is a schematic perspective view of an optical module system 10b according to Embodiment 2. FIG. FIG. 5 is a block diagram schematically showing the system configuration of the optical module system 10b according to the second embodiment. The arrows shown in FIG. 5 indicate the flow of control signals, control and data. Embodiment 2 is an optical module system 10b including the optical module 10a of Embodiment 1 and a controller 17. FIG.

4 and 5, an optical module system 10b according to the second embodiment includes an optical module 10a and a controller 17. FIG. In FIG. 4, the control unit 17 is schematically illustrated by a dashed line. The controller 17 is electrically connected to the first laser diode 41 , the second laser diode 42 , the third laser diode 43 , the electronic cooling module 30 , the first thermistor 34 and the second thermistor 35 . The control unit 17 controls currents supplied to the first laser diode 41 , the second laser diode 42 , the third laser diode 43 and the electronic cooling module 30 . Specifically, it controls the amount of current supplied to the first laser diode 41, the second laser diode 42, the third laser diode 43, and the electronic cooling module 30, the timing of supplying the current, and the like. The control unit 17 is also configured to be able to communicate with external electronic devices and the like via the network 29 .

The control unit 17 calculates the amount of heat generation Qh generated by the first laser diode 41, the second laser diode 42, and the third laser diode 43 from the information on the timing of light emission and the light emission amount (information on the light emission of the laser diode), Predict the required endothermic quantity Qc. Further, the control unit 17 controls the electronic cooling module 30 based on the predicted heat absorption amount Qc, the temperature of the heat sink 31 detected by the first thermistor 34, and the temperature of the heat sink 32 detected by the second thermistor 35. Find the current value to be supplied to The heat absorption amount Qc and the method for calculating the current value are as described in the first embodiment. In this way, the control unit 17 controls the current supplied to the electronic cooling module 30 based on the information for causing the laser diode to emit light, the temperature of the radiator plate 31 and the temperature of the heat absorbing plate 32 . Further, the control unit 17 controls the current supplied to the first laser diode 41, the second laser diode 42 and the third laser diode 43 based on the information for causing the laser diodes to emit light.

By doing so, the control by the control unit 17 is used to supply the electric current to the electronic cooling module 30 at appropriate timing, and the first laser diode 41, the second laser diode 42 and the third laser diode 42 attached to the heat absorption plate 32 The temperature of the laser diode 43 can be kept constant. Therefore, it is possible to further stabilize the output of emitted light.

In this embodiment, the control unit 17 controls the current to be supplied to the electronic cooling module 30 based on the information input to the first laser diode 41, the second laser diode 42, and the third laser diode 43 obtained from the outside. Control. Then, it is possible to grasp in advance the amount of heat generated by the first laser diode 41, the second laser diode 42 and the third laser diode 43, the heat generation timing, and the like, so that the first laser diode 41, the second laser diode 42 and the Current supply can be adjusted by predicting the amount of heat absorbed corresponding to the amount of heat generated by the third laser diode 43 . Therefore, it is possible to further stabilize the light output.

(Embodiment 3)
Next, Embodiment 3, which is another embodiment, will be described. FIG. 6 is an external perspective view showing the structure of the optical module 10c according to the third embodiment. FIG. 7 is an external perspective view showing a state in which the cap 14 of the optical module 10c shown in FIG. 6 is removed. FIG. 8 is a schematic plan view of the optical module 10c shown in FIG. The optical module 10c of the third embodiment differs from that of the first embodiment in that a mirror driving mechanism 70 is further provided.

6, 7 and 8, an optical module 10c of Embodiment 3 includes a first block portion 21, a second block portion 22 and a third block portion 23 each having a rectangular parallelepiped shape. The base plate 20 has a flat plate shape, and a first block portion 21, a second block portion 22, and a third block portion 23 are arranged on a first main surface 20a of the base plate 20 at intervals in the X direction. arranged side by side. A flat first submount 26 is arranged on the first block portion 21 . A planar second submount 27 is arranged on the second block portion 22 . A flat third submount 28 is arranged on the third block portion 23 . The second thermistor 35 is attached to the heat absorbing plate 32 with the base plate 20 and the first block portion 21 interposed therebetween. The first laser diode 41 is attached to the heat absorbing plate 32 with the base plate 20, the first block portion 21 and the first submount 26 interposed therebetween. The second laser diode 42 is attached to the heat absorbing plate 32 with the base plate 20, the second block portion 22 and the second submount 27 interposed therebetween. The third laser diode 43 is attached to the heat absorbing plate 32 with the base plate 20, the third block portion 23 and the third submount 28 interposed therebetween.

The optical module 10 c also includes a mirror driving mechanism 70 that scans the light emitted from the first laser diode 41 , the second laser diode 42 and the third laser diode 43 . The mirror driving mechanism 70 is configured by MEMS (Micro Electro Mechanical System) and includes a mirror 72 capable of rocking motion. The mirror driving mechanism 70 is supported by the electronic cooling module 30 , more specifically, by a triangular prism-shaped stage 71 arranged on the heat absorbing plate 32 . The mirror driving mechanism 70 oscillates the mirror 72 periodically at high speed to reflect the light emitted from the first laser diode 41, the second laser diode 42, and the third laser diode 43 and combined. The beams emitted from the first laser diode 41, the second laser diode 42 and the third laser diode 43 and combined are scanned. By emitting the scanned light from the emission window 18 to the outside of the optical module 10c, an image can be projected and drawn. The exit window 18 is provided above the cap 14 , that is, at a position facing the first main surface 13 a when the cap 14 is attached to the support plate 13 .

The mirror driving mechanism 70 periodically oscillates a mirror 72 that reflects the combined light beams emitted from the first laser diode 41, the second laser diode 42, and the third laser diode 43, so that the first laser diode 41, the The combined light emitted from the second laser diode 42 and the third laser diode 43 is scanned. Since the optical module 10c includes the mirror driving mechanism 70, the combined light emitted from the first laser diode 41, the second laser diode 42 and the third laser diode 43 can be scanned and emitted to the outside of the optical module 10c. can. Then, by the optical module 10c, drawing can be performed using the combined light beams emitted from the first laser diode 41, the second laser diode 42, and the third laser diode 43. FIG. Here, the oscillating motion of the mirror 72 is dependent on temperature, and if the temperature of the mirror drive mechanism 70 is not constant, the deflection angle of the mirror 72 will change greatly. Then, the combined light beams emitted from the first laser diode 41, the second laser diode 42 and the third laser diode 43 cannot be scanned appropriately. According to the optical module 10c, since the mirror driving mechanism 70 is attached to the heat absorbing plate 32, it becomes easy to keep the temperature of the mirror driving mechanism 70 constant. By doing so, it is possible to suppress the change in the deflection angle of the mirror 72 depending on the temperature. Therefore, it is possible to emit light that has been scanned with higher accuracy. As a result, drawing by the optical module 10c can be performed appropriately.

(Embodiment 4)
Embodiment 4, which is another embodiment, will be described. FIG. 9 is a schematic plan view of an optical module 10d according to the fourth embodiment. The optical module 10d of the fourth embodiment further includes a third thermistor 37 that detects the temperature of the laser diode, and differs from the third embodiment in that the second thermistor 35 is arranged on the heat absorbing plate 32. .

Referring to FIG. 9, an optical module 10d according to the fourth embodiment includes a third thermistor 37 that detects temperatures of a first laser diode 41, a second laser diode 42 and a third laser diode 43. FIG. The third thermistor 37 is arranged on the first block portion 21 . A second thermistor 35 for detecting the temperature of the heat absorbing plate 32 is arranged on the heat absorbing plate 32 . The second thermistor 35 may have a pedestal 36 between itself and the heat absorbing plate 32 . The pedestal 36 is preferably made of a material with high thermal conductivity, such as aluminum nitride (AlN). The second thermistor 35 is arranged at a corner of the base plate 20 near the first filter 61 when viewed in the Z-axis direction. That is, the second thermistor 35 is arranged far from each of the first laser diode 41 , the second laser diode 42 and the third laser diode 43 . Specifically, the second thermistor 35 and the first laser diode 41 are arranged with the first lens 51 and the first filter 61 interposed therebetween. By arranging the second thermistor 35 in this way, it becomes less susceptible to the heat generated by the laser, and the temperature of the heat absorbing plate can be read more accurately. The third thermistor 37 may be arranged on the second block portion 22 or the third block portion 23 .

According to such an optical module 10d, the temperature of the heat absorbing plate can be read more accurately. That is, the electric current supplied to the electronic cooling module 30 is adjusted based on the predicted amount of heat absorbed, the temperature of the heat sink 31 detected by the first thermistor 34, and the temperature of the heat sink 32 detected by the second thermistor 35. can do. Therefore, it is possible to further stabilize the output of emitted light.

Since the second thermistor 35 is located far away from the first laser diode 41, the second laser diode 42 and the third laser diode 43, the heat sources of the first laser diode 41, the second laser diode 42 and the second thermistor 35 The temperature of the heat absorbing plate 32 can be accurately detected without being affected by the third laser diode 43 . Therefore, the output of emitted light can be stabilized. A third thermistor 37 is used for monitoring the temperature of the laser diode. It can also be used to adjust the color tone of the laser diode according to temperature changes, making it possible to draw an image with a more adjusted color balance.

(Embodiment 5)
Embodiment 5, which is another embodiment, will be described. FIG. 10 is a schematic perspective view of an optical module system 10e according to Embodiment 5. FIG. FIG. 11 is a block diagram schematically showing the system configuration of the optical module system 10e according to the fifth embodiment. The arrows shown in FIG. 11 indicate the flow of control signals, control and data. The fifth embodiment is an optical module system 10e including the optical module 10c of the third embodiment and a controller 19. FIG.

10 and 11, an optical module system 10e according to the fifth embodiment includes a controller 19. FIG. In FIG. 10, the controller 19 is schematically illustrated by a dashed line. The controller 19 is electrically connected to the first laser diode 41 , the second laser diode 42 , the third laser diode 43 , the electronic cooling module 30 , the first thermistor 34 , the second thermistor 35 and the mirror drive mechanism 70 . . The control unit 19 controls currents supplied to the first laser diode 41 , the second laser diode 42 , the third laser diode 43 , the electronic cooling module 30 and the mirror driving mechanism 70 . Specifically, it controls the amount of current supplied to the first laser diode 41, the second laser diode 42, the third laser diode 43, the electronic cooling module 30, and the mirror driving mechanism 70, the timing of supplying the current, and the like. The control unit 19 is configured to be able to communicate with external electronic devices and the like via the network 29 .

The control unit 19 calculates the amount of heat generated by the first laser diode 41, the second laser diode 42, and the third laser diode 43 from the information on the timing of light emission and the amount of light emission (information on the light emission of the laser diodes). The current supplied to the cooling module 30 is adjusted. Specifically, the amount of heat generated by the first laser diode 41, the second laser diode 42, and the third laser diode 43, the heat generation timing, and the like can be grasped in advance from the information for causing the laser diodes to emit light. Current supply can be adjusted by predicting the amount of heat absorbed corresponding to the amount of heat generated by the laser diode 41, the second laser diode 42, and the third laser diode 43. FIG. Therefore, it is possible to further stabilize the light output. Thus, the control unit 19 controls the electric current supplied to the electronic cooling module 30 based on the information for causing the laser diode to emit light, the temperature of the radiator plate 31 and the temperature of the heat absorbing plate 32 . The control unit 19 also controls the current supplied to the first laser diode 41, the second laser diode 42, and the third laser diode 43 and the current supplied to the mirror driving mechanism 70 based on the information for causing the laser diodes to emit light.

By doing so, by using the control by the control unit 19, current is supplied to the electronic cooling module 30 at appropriate timing to absorb heat, and the first laser diode 41 and the second laser diode on the electronic cooling module 30 are cooled. 42 and the temperature of the third laser diode 43 can be kept constant. Therefore, it is possible to further stabilize the output of emitted light.

In this embodiment, since the mirror driving mechanism 70 is arranged on the electronic cooling module 30, drawing by the optical module system 10e can be performed appropriately.

(Other embodiments)
In addition, in the above embodiment, the laser diodes include one red laser diode, one green laser diode and one blue laser diode, but are not limited to this. The laser diodes may include one or more laser diodes of only one color. The laser diodes may include laser diodes of any two colors, or multiple laser diodes of those colors. Also, the laser diode includes at least one of a red laser diode, a green laser diode, and a blue laser diode, and may include a plurality of laser diodes of these colors.

Further, in the above embodiment, regarding the electronic cooling module, when the ambient environment where the optical module is arranged is, for example, extremely low temperature, the heat absorption plate side releases heat and the heat dissipation plate side absorbs heat. There is also

It should be understood that the embodiments disclosed this time are illustrative in all respects and not restrictive in any aspect. The scope of the present invention is defined by the scope of the claims rather than the above description, and is intended to include all changes within the meaning and scope of equivalence to the scope of the claims.

10a, 10c,

10d Optical modules

10b, 10e Optical module system 11 Light forming unit 12 Protective member 13

Supporting plates

13a, 13b, 20a, 20b Main surface 14

Caps

15, 18 Output window 16 Lead pins 17, 19 Control unit 20 Base plate 21 First block part 22 Second block part 23 Third block part 24

Thick parts

25, 36 Pedestal 26 First submount 27 Second submount 28 Third submount 29 Network 30 Electronic cooling module 31 Radiator plate 32 Heat absorption plate 33 Semiconductor column 34 First thermistor 35 Second thermistor 37 Third thermistor 41 First laser diode 42 Second laser diode 43 Third laser diode 51 First lens 52 Second lens 53 Third lens 61 First filter 62 Second filter 63 Third filter 70 Mirror driving mechanism 71 Stage 72 Mirrors L ₁ , L ₂ , L ₃ , L ₄ , X, Y, Z Arrows

Claims

a support plate;
an electronic cooling module having a radiator plate disposed on a first main surface of the support plate, a heat absorption plate, and a plurality of semiconductor columns connecting the heat radiation plate and the heat absorption plate;
at least one laser diode attached to the heat sink;
a first thermistor that detects the temperature of the radiator plate;
and a second thermistor that detects the temperature of the heat absorbing plate.
The optical module according to claim 1, wherein said first thermistor is arranged on said first main surface.
Equipped with a base plate,
3. The optical module according to claim 1, wherein said laser diode and said second thermistor are attached to said heat absorbing plate through said base plate.
The optical module according to any one of claims 1 and 2, further comprising a third thermistor that detects the temperature of said laser diode.
further comprising a filter that reflects light emitted from the laser diode,
5. The optical module according to claim 4, wherein said laser diode and said second thermistor are arranged with said filter interposed therebetween.
6. The electronic cooling module according to any one of claims 1 to 5, wherein the current supply is controlled so as to depend on the amount of heat generated by the laser diode calculated from information for causing the laser diode to emit light. Optical module as described.
The optical module according to any one of claims 1 to 6, wherein a plurality of said laser diodes are provided.
The optical module according to any one of claims 1 to 7, further comprising a mirror driving mechanism attached to said heat absorbing plate and scanning the light emitted from said laser diode.
an optical module according to any one of claims 1 to 8;
an optical module system, comprising: a control unit that calculates an amount of heat generated by the laser diode based on information for causing the laser diode to emit light.
The controller controls current supplied to the electronic cooling module based on the calculated amount of heat generated, the temperature detected by the first thermistor, and the temperature detected by the second thermistor. 10. The optical module system according to 9.