JP2024025960A - optical module - Google Patents

Abstract

To provide an optical module which enables facilitation of miniaturization of a device such as a projector and a ranging sensor in which the optical module is mounted, and enables facilitation of improvement of the quality of a projected image and an image obtained through sensing.SOLUTION: An optical module comprises: a base portion including a support plate having a first surface; a first laser diode mounted to the base portion; a reflecting mirror which reflects first light emitted from the first laser diode; a mirror drive mechanism which is mounted to the base portion and includes a scanning mirror scanning the first light reflected by the reflecting mirror; and a reflecting mirror support portion which is mounted to the base portion in such a way as to extend from the base portion and supports the reflecting mirror. The side surface of the reflecting mirror is mounted to a side surface which is the side surface of the reflecting mirror support portion and is perpendicular to the first surface.SELECTED DRAWING: Figure 3

Description

The present disclosure relates to optical modules.

An optical module that multiplexes and outputs laser light has been disclosed (see, for example, Patent Document 1 and Patent Document 2).

JP2021-77711A International Publication No. 2021/166466

An optical module using a laser diode may include a mirror drive mechanism that scans and emits light emitted from the laser diode. Such optical modules are used in projectors that project images by scanning emitted laser light, and in sensing the presence or absence of objects and their distance by scanning laser light and capturing the light reflected from objects with photodetectors. used for distance measurement sensors. The laser diode may emit visible light or infrared light, for example. In recent years, there has also been a demand for high-quality video projection, high-resolution sensing, and miniaturization of devices that have these functions. As a result, there is a demand for smaller optical modules installed in such devices.

Therefore, one of the objects of the present invention is to provide an optical module that facilitates miniaturization of mounted devices such as projectors and distance measurement sensors, and improvement of the quality of projected images and images obtained by sensing.

An optical module according to the present disclosure includes a base portion including a support plate having a first surface, a first laser diode attached to the base portion, and a reflector that reflects first light emitted from the first laser diode. a mirror, a mirror drive mechanism including a scanning mirror attached to the base and scanning the first light reflected by the reflection mirror; and a reflection mirror attached to the base so as to extend from the base and supporting the reflection mirror. A support part. The side surface of the reflective mirror is attached to the side surface of the reflective mirror support part that is perpendicular to the first surface.

According to such an optical module, it becomes easy to reduce the size of a mounted device such as a projector or a distance measurement sensor, and to improve the quality of a projected image or an image obtained by sensing.

FIG. 1 is an external perspective view showing the structure of the optical module according to the first embodiment. FIG. 2 is an external perspective view of the optical module shown in FIG. 1 with a cap, which will be described later, removed. FIG. 3 is a schematic plan view of the optical module shown in FIG. 2. FIG. 4 is a schematic side view of the optical module shown in FIG. 2. FIG. 5 is a schematic side view of the optical module shown in FIG. 2. FIG. 6 is an enlarged view showing a part of the optical module shown in FIG. 4. FIG. FIG. 7 is a schematic plan view of a mirror drive mechanism included in the optical module. FIG. 8 is an external perspective view showing the optical module according to the second embodiment with the cap removed. FIG. 9 is a schematic plan view of the optical module shown in FIG. 8. FIG. 10 is a schematic side view of the optical module shown in FIG. 8. FIG. 11 is a schematic side view showing a cap in cross section in the optical module according to the second embodiment.

[Description of embodiments of the present disclosure]
First, embodiments of the present disclosure will be listed and described. The optical module according to the present disclosure includes:
(1) A base part including a support plate having a first surface, a first laser diode attached to the base part, a reflecting mirror that reflects the first light emitted from the first laser diode, and a base part including a support plate having a first surface; A mirror drive mechanism including a scanning mirror that is attached to the mirror and scans the first light reflected by the reflecting mirror; and a reflecting mirror support that is attached to the base and extends from the base and supports the reflecting mirror. . The side surface of the reflective mirror is attached to the side surface of the reflective mirror support part that is perpendicular to the first surface.

According to such an optical module, the first light emitted from the first laser diode passes through the focusing and combining optical system, is reflected by the reflecting mirror, and enters the scanning mirror included in the mirror drive mechanism. In order to suppress the scanning distortion of the laser beam scanned by the scanning mirror, it is necessary to reduce the angle between the incident light on the scanning mirror surface and the reflected light on the scanning mirror, preferably within 40°. By the way, in the conventional configuration, the first light emitted from the first laser diode passes through the focusing and combining optical system and then directly enters the scanning mirror, so the angle between the incident light and the reflected light on the scanning mirror surface is When the angle is within 40°, the members constituting the condensing/combining optical system and the light reflected by the scanning mirror tend to interfere with each other. Therefore, the distance between the members constituting the converging and multiplexing optical system and the scanning mirror is increased to avoid interference, but in this case the optical module becomes larger. On the other hand, in the optical module according to the present disclosure, it is possible to increase the angle between the incident light and the reflected light on the scanning mirror surface. As a result, even if the distance between the members constituting the converging and multiplexing optical system and the scanning mirror is shortened, it is possible to prevent interference between the members constituting the condensing and multiplexing optical system and the reflected light on the scanning mirror surface. , it is possible to downsize the optical module. Further, when the conventional optical module and the optical module according to the present disclosure have the same size, the optical module according to the present disclosure can easily secure a wide mounting space for the condensing optical system. As a result, it has become easier to use lenses with longer focal lengths that require a longer distance between the laser diode and the lens or can reduce the beam diameter of the collimated light. It is possible to improve the quality of projected images and images obtained by sensing.

Regarding the method of fixing the reflecting mirror, usually, for example, the reflecting mirror support part is formed of a surface parallel to the first surface, and the side surface of the reflecting mirror is attached to that surface. However, during actual manufacturing, the center of the reflecting mirror and the center of the incident light always deviate from the design, so it is necessary to allow some leeway in the size of the reflecting mirror, and as a result, interference between the scanned laser beam and the reflecting mirror must be adjusted. In order to prevent this, it is necessary to increase the size of the optical module. On the other hand, in the optical module according to the present disclosure, it is possible to detect the deviation of the center of the reflecting mirror from the design, and precisely adjust both the position and angle of the reflecting mirror to fix it. As a result, the size of the reflecting mirror can be minimized with respect to the beam diameter of the incident light, and the optical module can be miniaturized.

Here, when trying to downsize the reflecting mirror, it is difficult to adjust the position of the reflecting mirror in order to appropriately enter the first light emitted from the first laser diode and reflect it to the position where the scanning mirror is arranged. becomes. According to the optical module of the present disclosure, since the side surface of the reflective mirror is attached to the side surface of the reflective mirror support and perpendicular to the first surface, the first laser diode emitted from the first laser diode It becomes easy to finely adjust the angle and position of the reflecting mirror in consideration of the optical axis of the light and the scanning direction of the first light scanned by the scanning mirror. Therefore, according to the optical module having such a configuration, it is easy to reduce the size of the mounted device such as a projector or a distance measurement sensor, and to improve the image quality of the projected image or the image obtained by sensing.

(2) In (1) above, the base portion may include an electronic cooling module having a heat sink, a heat absorbing plate, and a plurality of semiconductor pillars connecting the heat sink and the heat absorbing plate. The first laser diode and mirror drive mechanism may be attached to the heat absorption plate. By doing so, the temperatures of the first laser diode and the mirror drive mechanism can be adjusted depending on the temperature of the environment. Therefore, it is possible to stabilize the light output and the deflection angle of the scanning mirror. As a result, projection and sensing can be performed with high reproducibility, making it easier to achieve even higher image quality.

(3) In (1) or (2) above, the device may further include an optical component that adjusts the first light emitted from the first laser diode. The base part includes a pedestal arranged at a distance from the first surface and on which the mirror drive mechanism is placed, a base plate arranged at a distance from the first surface and on which the optical component is placed, and a base plate. and a mount section on which the first laser diode is mounted, which is spaced apart from the mount section. The height from the first surface to the pedestal, the height from the first surface to the support plate, and the height from the first surface to the mount portion may increase in this order. The first laser diode generates heat during operation. By doing so, the first laser diode can be placed at a high position and kept away from the optical components and the mirror drive mechanism, and the optical components and the mirror drive mechanism arranged on the base plate can be placed at a high position. The influence of the heat generated by the first laser diode on the temperature can be reduced as much as possible. Therefore, it is possible to maintain stable operation of the mirror drive mechanism and perform projection and sensing with high reproducibility, making it easier to achieve higher image quality.

(4) In any one of (1) to (3) above, the reflective mirror support portion includes at least a portion of the first region provided in contact with the base portion and the first region provided in contact with the base portion, when viewed in a direction perpendicular to the first surface. and a second region overlapping the mirror drive mechanism. The side surface of the reflective mirror may be attached to the side surface perpendicular to the first surface of the base part in the second region. By doing this, it is possible to make the device configuration more compact, while also making it easier to finely adjust the angle and position of the reflecting mirror, and suppressing the loss of light that deviates from the designed optical path. This makes it easier to improve image quality.

(5) In any one of (1) to (3) above, the reflective mirror support part has a first region and a third region provided in contact with the base part, and the reflection mirror support part when viewed in a direction perpendicular to the first surface. , and a second region at least partially overlapping with the mirror drive mechanism. The second region may be provided so as to straddle the mirror drive mechanism and connect the first region and the third region. The second region may include a cutout. The side surface of the reflective mirror may be attached to the notch. By doing so, it becomes easy to appropriately attach the reflecting mirror using the notch in the second region. In this case, it is possible to reduce the possibility that a portion of the reflective mirror support section other than the portion to which the reflective mirror is attached will block the optical path. Therefore, it is possible to more efficiently downsize the device configuration.

(6) In any one of (1) to (5) above, the mirror drive mechanism may be attached so that the reflective surface of the scanning mirror is parallel to the first surface. By doing so, the mirror drive mechanism can be easily attached, the device configuration can be simplified, and costs can be easily reduced.

(7) In (4) above, the side surface of the second region is the end of the reflective mirror support, and the reflective surface of the scanning mirror is aligned with the optical axis of the first light emitted from the first laser diode. It may also be provided at an angle with respect to the other direction. By doing so, the direction of light emitted by the optical module can be easily and arbitrarily adjusted while making the device configuration more compact.

(8) In any of (3) to (7) above, the optical component may include a lens that converts the spot size of the first light emitted from the first laser diode. By doing so, light having a desired spot size can be emitted from the optical module.

(9) Any one of (3) to (8) above may further include a second laser diode that is attached to the base and emits second light having a different wavelength from the first light. The optical component may include a filter that combines the first light emitted from the first laser diode and the second light emitted from the second laser diode. By doing this, the optical module emits light that is a combination of the first light emitted from the first laser diode and the second light emitted from the second laser diode. be able to.

(10) In any one of (3) to (9) above, the distance between the mirror drive mechanism and the base plate may be 1 mm or less. By doing so, the base plate can be made as wide as possible to promote heat diffusion. Therefore, since the effects of heat generation can be reduced, even if the vibration characteristics of the mirror drive mechanism change due to temperature fluctuations, it is easy to maintain stable operation of the mirror drive mechanism and achieve higher image quality. becomes.

(11) In any one of (3) to (10) above, the optical module includes a second laser that is placed in contact with the mount part and that emits second light of a color different from the first light. a third laser diode disposed in contact with the mount portion and emitting a third light having a color different from both the first light color and the second light color; and the first light color. and a fourth laser diode that emits fourth light of the same color. The optical component includes a first filter that reflects the first light, transmits the first light reflected by the first filter, and reflects the second light to separate the first light and the second light. A second filter for multiplexing, and a first combined light that is a combined light of the first light and second light combined by the second filter is transmitted, and the third light is reflected to produce the first combined light. a third filter that combines the first combined light and the third light, a fourth filter that reflects the fourth light, and a third filter that is the combined light of the first combined light and the third light combined by the third filter. The splitter may include a splitter that transmits the two combined lights and reflects the fourth light reflected by the fourth filter to combine the second combined lights and the fourth light. The base portion may include a block portion disposed in contact with the first surface and on which the mount portion rests. The side surface of the block portion on the mirror drive mechanism side may be closer to the mirror drive mechanism than the position where the second combined light and the fourth light are combined in the splitter. By doing so, the block portion can be positioned close to the mirror drive mechanism, and the heat generated from each laser diode can be transmitted to the wide block portion to promote heat diffusion. Therefore, it is possible to suppress the temperature of the mirror drive mechanism from fluctuating due to the variation in the amount of heat generated by each laser diode due to turning on or off of each laser diode, and to maintain stable operation of the mirror drive mechanism. It becomes easier to achieve higher image quality.

[Details of embodiments 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 or corresponding parts are given the same reference numerals, and the description thereof will not be repeated.

(Embodiment 1)
An optical module in Embodiment 1 of the present disclosure will be described. FIG. 1 is an external perspective view showing the structure of the optical module according to the first embodiment. FIG. 2 is an external perspective view of the optical module shown in FIG. 1 with a cap, which will be described later, removed. FIG. 3 is a schematic plan view of the optical module shown in FIG. 2. 4 and 5 are schematic side views of the optical module shown in FIG. 2. 4 is a side view seen from the direction indicated by arrow Y, and FIG. 5 is a side view seen from the direction opposite to arrow X. FIG. 6 is an enlarged view showing a part of the optical module shown in FIG. 4. FIG.

1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, and FIG. 6, the optical module 10a includes a base portion 11, a cap 12 as a protection member, a plurality of laser diodes, and a plurality of optical components. , a mirror drive mechanism 50 including a scanning mirror 52 that scans light, a reflective mirror 67 that reflects light, and a reflective mirror support portion 70a that supports reflective mirror 67. In this embodiment, the base part 11 includes a flat support plate 13, a flat base plate 14, an electronic cooling module 30, and block parts (first block part 17a, second block part 17b), It includes a plurality of mount parts (a first mount part 18a, a second mount part 18b, a third mount part 18c, a fourth mount part 18d, and a fifth mount part 18e). The cap 12 is a lid part welded to the support plate 13. Components placed on the support plate 13 are surrounded and sealed by the support plate 13 and the cap 12. The support plate 13 has a rectangular shape when viewed from the Z direction, and has four rounded corners. Specifically, the support plate 13 is configured such that the length in the X direction is longer than the length in the Y direction.

The support plate 13 includes a first surface 13a located on one side in the thickness direction and a second surface 13b located on the other side in the thickness direction. That is, the base portion 11 includes the first surface 13a. The first surface 13a and the second surface 13b are each a surface perpendicular to the Z direction, that is, a surface parallel to the XY plane. Cap 12 is placed in contact with first surface 13a. The cap 12 is provided with an exit window 15 that transmits light. The plurality of laser diodes and the plurality of optical components arranged on the support plate 13, the mirror drive mechanism 50, the reflection mirror 67, and the reflection mirror support part 70a are hermetically sealed by the cap 12. The exit window 15 is provided on the upper side of the cap 12, that is, at a position facing the first surface 13a when the cap 12 is attached to the support plate 13. A plurality of lead pins 16 are attached to the support plate 13 so as to penetrate from the second surface 13b side to the first surface 13a side of the support plate 13 and protrude from both the first surface 13a side and the second surface 13b side. It is installed in

The base plate 14 includes a first main surface 14a located on one side in the thickness direction and a second main surface 14b located on the other side in the thickness direction. The first main surface 14a and the second main surface 14b are each a surface perpendicular to the Z direction, that is, a surface parallel to the XY plane.

The electronic cooling module 30 adjusts the temperature of each member on the electronic cooling module 30. The electronic cooling module 30 is also called a TEC (Thermo-Electric Cooler), and includes a heat sink 31, a heat absorbing plate 32, and a plurality of semiconductor pillars 33. The electronic cooling module 30 is arranged on the support plate 13, specifically on the first surface 13a of the support plate 13. The base plate 14 is placed on the electronic cooling module 30. That is, the electronic cooling module 30 is arranged so as to be sandwiched between the support plate 13 and the base plate 14 in the Z direction. In the electronic cooling module 30, the heat sink 31 is arranged so as to be in contact with the first surface 13a of the support plate 13. The heat absorbing plate 32 is arranged so as to be in contact with the second main surface 14b of the base plate 14. The support plate 13 and the heat radiation plate 31, and the base plate 14 and the heat absorption plate 32 are each bonded by 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 heat sink plate 31 and the heat absorption plate 32. The plurality of semiconductor pillars 33 are connected to the heat sink plate 31 and the heat absorption plate 32, respectively. By supplying electricity to the electronic cooling module 30, the temperature of each member on the electronic cooling module 30 can be adjusted. By adjusting the current supplied to the electronic cooling module 30, it becomes easy to maintain each member on the electronic cooling module 30 at a constant temperature over a long period of time, specifically, for example, at 35°C.

The first block portion 17a and the second block portion 17b each have a rectangular parallelepiped shape. The first block portion 17a and the second block portion 17b are arranged on the first main surface 14a of the base plate 14. The first block portion 17a is configured such that the length in the X direction is longer than the length in the Y direction when viewed in the Z direction. The second block portion 17b is configured such that the length in the Y direction is longer than the length in the X direction when viewed in the Z direction. The first mount section 18a, second mount section 18b, and third mount section 18c included in the base section 11 are arranged in contact with the first block section 17a. The first mount part 18a, the second mount part 18b, and the third mount part 18c are arranged on the first block part 17a, as shown in FIG. 2 and the like. The fourth mount section 18d and the fifth mount section 18e included in the base section 11 are arranged in contact with the second block section 17b. The fourth mount part 18d and the fifth mount part 18e are arranged on the second block part 17b, as shown in FIG. 2 and the like. The first mount part 18a, the second mount part 18b, and the third mount part 18c are arranged side by side in the direction opposite to the arrow X with a space therebetween. The fourth mount part 18d and the fifth mount part 18e are arranged in the direction opposite to the arrow Y and spaced apart from each other. Note that the base portion 11 includes a partition plate 19 disposed on the base plate 14 so as to rise from the base plate 14. The partition plate 19 is provided with a through hole 20 that penetrates in the X direction.

The optical module 10a includes a plurality of laser diodes (a first laser diode 41a, a second laser diode 41b, a third laser diode 41c, a fourth laser diode 41d, and a fifth laser diode 41e). In this embodiment, the first laser diode 41a, the second laser diode 41b, the third laser diode 41c, the fourth laser diode 41d, and the fifth laser diode 41e are each composed of a semiconductor light emitting element. The first laser diode 41a emits first light _L1 that is red light. The second laser diode 41b emits second light _L2 that is green light. The third laser diode 41c emits third light _L3 that is blue light. The fourth laser diode 41d emits fourth light _L4 that is red light. The fifth laser diode 41e emits fifth light _L5 that is green light.

The first laser diode 41a is placed on the first mount section 18a. The first laser diode 41a emits the first light _L1 in the Y direction (direction of arrow Y). The second laser diode 41b is placed on the second mount portion 18b. The second laser diode 41b emits second light _L2 in the Y direction (direction of arrow Y). The third laser diode 41c is placed on the third mount section 18c. The third laser diode 41c emits third light _L3 in the Y direction (direction of arrow Y). The fourth laser diode 41d is placed on the fourth mount portion 18d. The fourth laser diode 41d emits fourth light _L4 in the X direction (opposite direction to arrow X). The fifth laser diode 41e is placed on the fifth mount portion 18e. The fifth laser diode 41e emits the fifth light _L5 in the X direction (opposite direction to the arrow X). Here, in particular, the first laser diode 41a and the fourth laser diode 41d that emit red light have relatively high temperature dependence. Further, the second laser diode 41b and the fifth laser diode 41e, which emit green light in particular, generate a large amount of heat during operation. As described above, by adopting the configuration in which the second laser diode 41b is arranged next to the first laser diode 41a and the fifth laser diode 41e is arranged next to the fourth laser diode 41d, the first laser diode 41a and the fourth laser diode 41d can be arranged at the same distance from the second laser diode 41b and the fifth laser diode 41e, which generate a large amount of heat, respectively, thereby suppressing temperature fluctuations of the first laser diode 41a and the fourth laser diode 41d. can do. Therefore, it becomes easier to make the temperature distribution uniform, and it is possible to further stabilize the output from each laser diode.

The optical module 10a includes a plurality of lenses (a first lens 42a, a second lens 42b, a third lens 42c, a fourth lens 42d, and a fifth lens 42e) as optical components. The first lens 42a, the second lens 42b, the third lens 42c, the fourth lens 42d, and the fifth lens 42e are each placed above the heat absorption plate 32, specifically, on the first main surface 14a of the base plate 14. It is placed there. The first lens 42a, the second lens 42b, the third lens 42c, the fourth lens 42d, and the fifth lens 42e are the first laser diode 41a, the second laser diode 41b, the third laser diode 41c, and the fourth laser diode 41d, respectively. and converts the spot size of the light emitted from the fifth laser diode 41e. Specifically, each lens is arranged in the emission direction of the light emitted from each laser diode, and converts the light emitted from each laser diode into collimated light. In this way, each lens adjusts the light emitted from each laser diode.

The optical module 10a includes a plurality of filters (a first filter 43a, a second filter 43b, a third filter 43c, a fourth filter 43d, and a fifth filter 43e) as optical components. The first filter 43a, the second filter 43b, the third filter 43c, the fourth filter 43d, and the fifth filter 43e are each placed above the heat absorption plate 32, specifically, on the first main surface 14a of the base plate 14. It is placed. The first filter 43a, the second filter 43b, the third filter 43c, the fourth filter 43d, and the fifth filter 43e are the first laser diode 41a, the second laser diode 41b, the third laser diode 41c, and the fourth laser diode 41d, respectively. and is arranged in the emission direction of the light emitted from the fifth laser diode 41e. The first filter 43a reflects the first light _L1 in the X direction (opposite direction to arrow X). The second filter 43b transmits the first light _L1 and reflects the second light _L2 in the X direction (opposite direction to the arrow X). In this way, the first light _L1 and the second light _L2 are combined. The third filter 43c transmits the first combined light _LX , which is a combination of the first light _L1 and the second light _L2 , and transmits the third light _L3 in the direction). Thereby, the first combined light _LX and the third light _L3 are combined. The second combined light LY, which is a combination of the first combined light _LX and _the third light _L3 , travels in the X direction (in the opposite direction to the arrow X). The fourth filter 43d reflects the fourth light _L4 in the Y direction (opposite direction to arrow Y). The fifth filter 43e transmits the fourth light _L4 and reflects the fifth light _L5 in the Y direction (opposite direction to the arrow Y). In this way, the fourth light _L4 and the fifth light _L5 are combined.

The optical module 10a includes a half-wave plate (1/2-wave plate) 44 and a beam splitter 45. The half-wave plate 44 and the beam splitter 45 are each placed above the heat absorption plate 32, specifically, on the first main surface 14a of the base plate 14. The half-wave plate 44 is arranged in the traveling direction of the third combined light _LZ , which is a combination of the fourth light _L4 and the fifth light _L5 . The half-wave plate 44 rotates the polarization direction of the third combined light _LZ by 90 degrees. The half-wave plate 44 allows the polarization direction of the first light _L1 of the second combined light _LY to be orthogonal to the polarization direction of the fourth light _L4 of the third combined light _LZ . Become. Further, the polarization direction of the second light L2 of the _{second combined light LY and} the polarization direction of the fifth light _L5 of the third combined light _LZ are orthogonal to each other. Beam splitter 45 is polarization dependent. Beam splitter 45 has a cube shape. The beam splitter 45 transmits the second combined light _LY and reflects the third combined light _LZ . In this way, the second combined light L _Y and the third combined light L _Z are combined to obtain the fourth combined light L _W. The fourth combined light _LW traveling in the X direction (opposite direction to arrow X) is a combination of two red lights, two green lights, and one blue light, and has high output. can be realized. The fourth combined light _LW combined by the beam splitter 45 passes through the through hole 20 provided in the partition plate 19 and travels in the X direction (opposite direction to the arrow X). This fourth combined light _LW is used by the mirror drive mechanism 50 to draw a projected image. Note that the side surface of the first block portion 17a on the mirror drive mechanism 50 side is closer to the mirror drive mechanism 50 than the position where the second combined light L _Y and the fourth light _L4 are combined in the beam splitter 45. It consists of close to.

The optical module 10a includes a first thermistor 21a and a second thermistor 21b. The first thermistor 21a is placed on a base portion 22 placed on the first surface 13a of the support plate 13. The base portion 22 is arranged adjacent to the heat sink 31. The temperature of the support plate 13 can be detected using the first thermistor 21a. The second thermistor 21b is arranged on the first block portion 17a. The second thermistor 21b is placed near the second laser diode 41b. Using the second thermistor 21b, it is possible to detect the temperature of the first block portion 17a and, by extension, the area on the heat absorbing plate 32. The temperature detected by the first thermistor 21a and the second thermistor 21b is used by the electronic cooling module 30 for temperature adjustment.

The mirror drive mechanism 50 included in the optical module 10a is arranged on the electronic cooling module 30, specifically, on the heat absorption plate 32. FIG. 7 is a schematic plan view of the mirror drive mechanism 50 included in the optical module 10a. Note that in figures other than FIG. 7, illustration of the mirror drive mechanism 50 is simplified.

Referring also to FIG. 7, the mirror drive mechanism 50 includes a frame portion 51, a disk-shaped scanning mirror 52 having a reflective surface 55, and a support portion 53 that supports the scanning mirror 52. The scanning mirror 52 is configured to be able to swing around a first swing axis 59a and a second swing axis 59b, respectively indicated by dashed lines. The first swing axis 59a is a virtual axis extending along the _D2 direction in FIG. 7, and the second swing axis 59b is a virtual axis extending along the _D1 direction in FIG. The _D1 direction and the _D2 direction are orthogonal. When assembling the optical module 10a, the mirror drive mechanism 50 should be attached in the direction shown by arrow _D1 as shown in arrow X shown in FIG. 1, etc., and the direction shown by arrow _D2 in FIG. The direction is indicated by arrow Y shown in .

A first through hole 57a is provided in the frame portion 51, and a support portion 53 that supports the scanning mirror 52 is provided within the first through hole 57a. The support portion 53 is provided with a second through hole 57b, and the scanning mirror 52 is moved within the second through hole 57b by a pair of thin rod-shaped shaft portions 54a, 54b. It is supported so that it can swing around the center. When the scanning mirror 52 swings about the second swing axis 59b, four piezoelectric elements 56a, 56b, 56c, and 56d attached to the support portion 53 are used.

The support portion 53 has a plate shape, and includes a plurality of first portions 61a, 61b, 61c, 61d, 61e, 61f, 61g, and 61h extending along the _D1 direction, and adjacent first portions 61a to 61h, respectively. The plurality of second portions 62a, 62b, 62c, 62d, 62e, and 62f to be connected, the connecting portions 63a and 63b that connect the support portion 53 and the frame portion 51, and the scanning mirror 52 are connected via the shaft portions 54a and 54b. It includes an attachment part 58 to be attached, and connection parts 63c and 63d that connect the first parts 61d and 61h and the attachment part 58. The second portions 62a to 62f alternately connect one longitudinal end of the adjacent first portions 61a to 61h and the other longitudinal ends of the adjacent first portions 61a to 61h. When the scanning mirror 52 swings about the first swing axis 59a, the piezoelectric elements 64a, 64b, 64c, 64d, 64e attached to the support portion 53, specifically, the first portions 61a to 61h. , 64f, 64g, and 64h are used. For example, piezoelectric elements are used as the piezoelectric elements 56a to 56d and 64a to 64h. The support portion 53 has a so-called meander structure.

The mirror drive mechanism 50 swings the scanning mirror 52 around a first swing axis 59a and a second swing axis 59b, respectively, while adjusting the voltages supplied to the piezoelectric elements 56a to 56d and 64a to 64h. make it move.

The base portion 11 includes pedestals 65a and 66a. Each of the pedestals 65a and 66a has a rod shape extending in the Y direction. The pedestals 65a and 66a are arranged on the base portion 11, specifically, on the heat absorption plate 32, with an interval in the X direction. The mirror drive mechanism 50 is placed on the pedestals 65a and 66a. In this embodiment, the heights of the pedestals 65a and 66a in the Z direction are the same, and the reflective surface 55 of the scanning mirror 52 is attached parallel to the first surface 13a. Parallel here means parallel when the scanning mirror 52 is not swinging. A gap is formed between the mirror drive mechanism 50 and the heat absorption plate 32.

Here, the height from the first surface 13a to the pedestals 65a and 66a is the height _H1 , the height from the first surface 13a to the base plate 14 is the height _H2 , and the height from the first surface 13a to the first Assuming that the height from the mount part 18a to the fifth mount part 18e is a height _H3 , the height increases in the order of height _H1 , height _H2 , and height _H3 . Further, a gap is formed between the mirror drive mechanism 50 and the base plate 14 in the X direction. In this embodiment, the distance S between the mirror drive mechanism 50 and the base plate 14 is 1 mm or less.

The reflective mirror 67 included in the optical module 10a includes a reflective surface 68 that reflects light, and a side surface 69 that is continuous with the reflective surface 68 and intersects with the reflective surface 68. The reflective surface 68 is a flat surface. The external shape of the reflective mirror 67 is rectangular when viewed in a direction perpendicular to the reflective surface 68.

A reflective mirror support section 70a included in the optical module 10a supports the reflective mirror 67. The reflective mirror support part 70a is arranged on the electronic cooling module 30, specifically, on the heat absorption plate 32. The reflective mirror support portion 70a includes a first region 71a, a second region 72a, and a third region 73. The first region 71a and the third region 73 are provided in contact with the base portion 11, specifically, the heat absorption plate 32. The second region 72a overlaps the mirror drive mechanism 50 when viewed in the direction (Z direction) perpendicular to the first surface 13a. The second region 72a is provided so as to straddle the mirror drive mechanism 50 and connect the first region 71a and the third region 73.

The second region 72a includes a cutout portion 74. The cutout portion 74 is provided such that the height from the first surface 13a on the first region 71a side is higher than the height from the first surface 13a on the third region 73 side. The cutout portion 74 includes a side surface 75a of the reflective mirror support portion 70a. The side surface 75a is a side surface perpendicular to the first surface 13a.

Here, the reflection mirror 67 is attached to the reflection mirror support part 70a. Specifically, the side surface 69 of the reflection mirror 67 is attached to the side surface 75a of the reflection mirror support part 70a. When attaching the reflecting mirror 67, fine adjustments are made using adhesive and taking into consideration the position of the optical axis of the fourth combined light _LW , the center position of the reflecting surface 55 of the scanning mirror 52, and the like.

Next, the projection of an image by the optical module 10a and the irradiation of sensing light onto an object will be explained. As described above, the respective lights emitted from the first laser diode 41a, the second laser diode 41b, the third laser diode 41c, the fourth laser diode 41d, and the fifth laser diode 41e are multiplexed, and then It travels in the X direction (opposite direction to arrow X) as 4-combined light _LW . Thereafter, the fourth combined light _LW passes through the through hole 20 of the partition plate 19 and reaches the reflection mirror 67. The combined light that has reached the reflection mirror 67 is reflected by the reflection surface 68 of the reflection mirror 67, travels along the optical path _LU , and enters the scanning mirror 52 included in the mirror drive mechanism 50. The combined light incident on the scanning mirror 52 is reflected by the reflecting surface 55 of the scanning mirror 52, and is emitted from the exit window 15 of the cap 12 to the outside of the optical module 10a.

Here, the scanning mirror 52 is oscillated at high speed by the mirror drive mechanism 50 about a first oscillation axis 59a and a second oscillation axis 59b that are perpendicular to each other. Therefore, the combined light reflected by the reflective surface 68 of the reflective mirror 67 and incident on the scanning mirror 52 is reflected by the reflective surface 55 of the scanning mirror 52, which is the scanning mirror surface, and is rotated between the first swing axis 59a and the second swing axis. Due to the swinging of the shaft 59b, light is emitted within the range of the optical path L _S and the optical path L _R that are defined by the angle θ ₁ , respectively, with the optical axis L _T as the center, and is used for drawing images and irradiating sensing light outside the optical module 10 a. do.

According to the optical module 10a of the present disclosure, since the combined light including the first light _L1 emitted from the first laser diode 41a is not configured to directly enter the scanning mirror 52, the projection of the image by the scanning mirror 52 is taken into consideration. This increases design latitude and facilitates miniaturization. Furthermore, the position of the scanning mirror 52 can be set relatively far from the emission position of the first laser diode 41a, and the beam diameter can be made small at the condensing position, which is the writing position, and high image quality can be achieved. . In this case, in order to reduce the size of the device, it is also easy to reduce the size of the reflecting mirror 67. This makes it easy to prevent interference between the emitted light and the reflecting mirror 67 even when the deflection angle of the scanning mirror 52 is increased.

Further, according to the optical module 10a of the present disclosure, the side surface 69 of the reflective mirror 67 is attached to the side surface 75a of the reflective mirror support portion 70a and is perpendicular to the first surface 13a. The angle and position of the reflecting mirror 67 are finely adjusted in consideration of the optical axis of the combined light including the first light emitted from the laser diode 41a and the scanning direction of the combined light including the first light scanned by the scanning mirror 52. It becomes easy to adjust. Therefore, according to the optical module 10a having such a configuration, it becomes easy to reduce the size of the mounted device such as a projector or a distance measurement sensor, and to improve the image quality of a projected image or an image obtained by sensing.

In this embodiment, the base portion 11 includes an electronic cooling module 30 having a heat sink 31, a heat absorbing plate 32, and a plurality of semiconductor columns 33 connecting the heat sink 31 and the heat absorbing plate 32. Each laser diode and mirror drive mechanism 50 are attached to the heat absorption plate 32. Therefore, the temperature of each laser diode including the first laser diode 41a and the mirror drive mechanism 50 can be adjusted according to the temperature of the environment. Therefore, it is possible to stabilize the light output and the deflection angle of the scanning mirror 52. As a result, projection and sensing can be performed with high reproducibility, making it easier to achieve even higher image quality.

In this embodiment, the base portion 11 is arranged at a distance from the first surface 13a, and the pedestals 65a and 66a on which the mirror drive mechanism 50 is placed are arranged at a distance from the first surface 13a. , a base plate 14 on which optical components are mounted, and mount parts 18a, 18b, 18c, 18d, which are arranged at intervals from the base plate 14 and on which each laser diode 41a, 41b, 41c, 41d, 41e is mounted. 18e. Height H 1 from the first surface 13a to the pedestals 65a, 66a _, Height H ₂ from the first surface 13a to the base plate 14, Height H from the first surface 13a to each mount part 18a to 18e The numbers are increasing in the order of ₃ . Each laser diode generates heat during operation, but by doing so, each laser diode can be placed at a high position and away from the optical components and the mirror drive mechanism 50, and can be placed on the base plate 14. The influence of the heat generated by each laser diode on the mirror drive mechanism 50 disposed on the optical components and the pedestals 65a and 66a can be reduced as much as possible. Therefore, it is possible to maintain stable operation of the mirror drive mechanism 50 and perform projection and sensing with high reproducibility, making it easier to achieve higher image quality.

In this embodiment, the reflective mirror support portion 70a includes a first region 71a and a third region 73 provided in contact with the heat absorbing plate 32, and a mirror drive mechanism 50 when viewed in a direction perpendicular to the first surface 13a. and a second region 72a overlapping with the second region 72a. The second region 72a is provided so as to straddle the mirror drive mechanism 50 and connect the first region 71a and the third region 73. The second region 72a includes a cutout portion 74. A side surface 69 of the reflective mirror 67 is attached to the notch 74 . Therefore, it becomes easy to properly attach the reflecting mirror 67 using the notch 74 in the second region 72a. In this case, it is possible to reduce the possibility that a portion of the reflective mirror support portion 70a other than the portion to which the reflective mirror 67 is attached will block the optical path. Therefore, while making the device configuration more efficient and compact, it becomes easier to finely adjust the angle and position of the reflecting mirror 67, and it is possible to suppress the loss of light that deviates from the designed optical path, resulting in higher image quality. This makes it easier to promote

In this embodiment, the distance S between the mirror drive mechanism 50 and the base plate 14 is 1 mm or less. Therefore, the base plate 14 can be made as wide as possible to promote heat diffusion. Therefore, since the influence of heat generation can be reduced, even if the vibration characteristics of the mirror drive mechanism 50 fluctuate due to temperature fluctuations, stable operation of the mirror drive mechanism 50 can be maintained and higher image quality can be achieved. becomes easier.

In this embodiment, the side surface of the first block portion 17a on the mirror drive mechanism 50 side is located at a position where the second combined light L _Y and the fourth light _L4 are combined in the beam splitter 45 Close to the mirror drive mechanism 50. Therefore, it is possible to suppress the temperature of the mirror drive mechanism 50 from fluctuating due to the effect of the heat generation amount of each laser diode changing due to turning on or off of each laser diode, and to maintain stable operation of the mirror drive mechanism 50. As a result, higher image quality can be achieved.

(Embodiment 2)
Embodiment 2, which is another embodiment, will be described. FIG. 8 is an external perspective view showing the optical module according to the second embodiment with the cap removed. FIG. 9 is a schematic plan view of the optical module shown in FIG. 8. FIG. 10 is a schematic side view of the optical module shown in FIG. 8. FIG. 10 is a side view seen from the direction indicated by arrow Y. FIG. 11 is a schematic side view showing a cap in cross section in the optical module according to the second embodiment. FIG. 11 is a side view seen from the direction opposite to arrow Y. The optical module in Embodiment 2 basically has the same configuration as Embodiment 1, and produces the same effects. However, the optical module of the second embodiment differs from that of the first embodiment in the configuration for attaching the mirror drive mechanism and the configuration of the reflective mirror support section.

Referring to FIGS. 8 to 11, the reflective mirror support portion 70b included in the optical module 10b of the second embodiment has a first region 71b provided in contact with the base portion 11, specifically, the heat absorption plate 32. and a second region 72b that overlaps with the mirror drive mechanism 50 when viewed in a direction perpendicular to the first surface 13a. A side surface 69 of the reflective mirror 67 is attached to a side surface 75b perpendicular to the first surface 13a in the second region 72b.

Furthermore, the pedestal 65b included in the optical module 10b in the second embodiment is composed of one triangular prism-shaped member. In this case, the mounting surface on which the mirror drive mechanism 50 is mounted is inclined with respect to the first surface 13a. That is, the reflective surface 55 of the scanning mirror 52 is provided to be inclined with respect to the optical axis of the fourth combined light _LW including the first light _L1 emitted from the first laser diode 41a.

According to the optical module 10b, the reflective mirror support portion 70b includes a first region 71b provided in contact with the base portion 11, specifically the heat absorption plate 32, and a direction perpendicular to the first surface 13a. A second region 72b overlapping with the mirror drive mechanism 50 is included. A side surface 69 of the reflective mirror 67 is attached to a side surface 75b perpendicular to the first surface 13a in the second region 72b. Therefore, it becomes easy to achieve high image quality while making the device configuration more compact.

In this embodiment, the side surface 75b of the second region 72b is the end of the reflective mirror support 70b, and the reflective surface 55 of the scanning mirror 52 is the end of the reflective mirror support 70b. It is provided to be inclined with respect to the optical axis of the multiplexed light including the optical axis of _{the first} optical axis. Therefore, the direction of light emitted by the optical module 10b can be easily and arbitrarily adjusted while making the device configuration more compact.

(Other embodiments)
Note that in the above embodiment, the base part includes the electronic cooling module, but the present invention is not limited to this, and the base part may have a configuration that does not include the electronic cooling module. In this case, for example, the first block portion or the like may be placed on the support plate.

Further, in the above embodiment, the optical module includes five laser diodes: a first laser diode, a second laser diode, a third laser diode, a fourth laser diode, and a fifth laser diode. For example, the configuration may include only three laser diodes, the first laser diode, the second laser diode, and the third laser diode.Furthermore, it may include an arbitrary number of laser diodes. It is also possible to have a configuration including one.

It should be understood that the embodiments disclosed herein are illustrative in all respects and are not restrictive in any respect. The scope of the present invention is defined not by the above description but by the claims, and it is intended that all changes within the meaning and scope equivalent to the claims are included.

10a, 10b Optical module 11 Base part 12 Cap 13 Support plate 13a First surface 13b Second surface 14 Base plate 14a First main surface 14b Second main surface 15 Output window 16 Lead pin 17a Block part (first block Department)
17b Block part (second block part)
18a Mount part (first mount part)
18b Mount part (second mount part)
18c Mount part (third mount part)
18d Mount part (4th mount part)
18e Mount part (5th mount part)
19 Partition plate 20 Through hole 21a First thermistor 21b Second thermistor 22 Base part 30 Electronic cooling module 31 Heat sink 32 Heat absorption plate 33 Semiconductor column 41a Laser diode (first laser diode)
41b Laser diode (second laser diode)
41c Laser diode (third laser diode)
41d Laser diode (4th laser diode)
41e Laser diode (5th laser diode)
42a lens (first lens)
42b lens (second lens)
42c lens (third lens)
42d lens (4th lens)
42e lens (5th lens)
43a Filter (first filter)
43b filter (second filter)
43c filter (third filter)
43d filter (4th filter)
43e Filter (5th filter)
44 Half-wave plate 45 Beam splitter 50 Mirror drive mechanism 51 Frame portion 52 Scanning mirror 53 Support portions 54a, 54b Shaft portions 55, 68 Reflective surfaces 56a, 56b, 56c, 56d, 64a, 64b, 64c, 64d, 64e, 64f, 64g, 64h Piezoelectric element 57a First through hole 57b Second through hole 58 Attachment part 59a First swing shaft 59b Second swing shaft 61a, 61b, 61c, 61d, 61e, 61f, 61g, 61h First portion 62a, 62b, 62c, 62d, 62e, 62f Second portion 63a, 63b Connection portion 63c, 63d Connection portion 65a, 65b, 66a Pedestal 67 Reflection mirror 69, 75a, 75b Side surface 70a, 70b Reflection mirror support portion 71a, 71b First area 72a, 72b Second area 73 Third area 74 Notch L ₁ First light L ₂ Second light L ₃ Third light L ₄ Fourth light L ₅ Fifth light L _X First combined light L _Y 2nd combined light L _Z 3rd combined light L _W 4th combined light H ₁ , H ₂ , H ₃ Height S Distance

Claims (11)

a base portion including a support plate having a first surface;
a first laser diode attached to the base;
a reflecting mirror that reflects the first light emitted from the first laser diode;
a mirror drive mechanism including a scanning mirror attached to the base portion and scanning the first light reflected by the reflecting mirror;
a reflective mirror support part that is attached to the base part so as to extend from the base part and supports the reflective mirror,
In the optical module, the side surface of the reflective mirror is attached to a side surface of the reflective mirror support part that is perpendicular to the first surface. The base part includes an electronic cooling module having a heat sink, a heat absorbing plate, and a plurality of semiconductor columns connecting the heat sink and the heat absorbing plate,
The optical module according to claim 1, wherein the first laser diode and the mirror drive mechanism are attached to the heat absorption plate. further comprising an optical component that adjusts the first light emitted from the first laser diode,
The base portion is
a pedestal arranged at a distance from the first surface and on which the mirror drive mechanism is placed;
a base plate arranged at a distance from the first surface and on which the optical component is placed;
a mount portion disposed at a distance from the base plate and on which the first laser diode is placed;
10. The height from the first surface to the pedestal, the height from the first surface to the base plate, and the height from the first surface to the mount portion increase in this order. Item 2. The optical module according to item 2. The reflective mirror support part is
a first region provided in contact with the base portion;
a second region that at least partially overlaps the mirror drive mechanism when viewed in a direction perpendicular to the first surface;
The optical module according to claim 1 or 2, wherein a side surface of the reflective mirror is attached to a side surface perpendicular to the first surface of the base portion in the second region. The reflective mirror support part is
a first region and a third region provided in contact with the base portion;
a second region that at least partially overlaps the mirror drive mechanism when viewed in a direction perpendicular to the first surface;
The second region is provided so as to straddle the mirror drive mechanism and connect the first region and the third region,
The second region includes a notch,
The optical module according to claim 1 or 2, wherein a side surface of the reflective mirror is attached to the notch. The optical module according to claim 1 or 2, wherein the mirror drive mechanism is attached so that a reflective surface of the scanning mirror is parallel to the first surface. The side surface of the second region is an end of the reflective mirror support,
The optical module according to claim 4, wherein the reflective surface of the scanning mirror is provided to be inclined with respect to the optical axis of the first light emitted from the first laser diode. The optical module according to claim 3, wherein the optical component includes a lens that converts a spot size of the first light emitted from the first laser diode. further comprising a second laser diode attached to the base portion and emitting a second light having a different wavelength from the first light;
The optical component according to claim 3, wherein the optical component includes a filter that combines the first light emitted from the first laser diode and the second light emitted from the second laser diode. module. The optical module according to claim 3, wherein a distance between the mirror drive mechanism and the base plate is 1 mm or less. a second laser diode that is disposed in contact with the mount and emits a second light of a color different from the first light;
a third laser diode that is disposed in contact with the mount and emits a third light having a color different from both the first light and the second light;
a fourth laser diode that emits fourth light of the same color as the first light;
The optical component is
a first filter that reflects the first light;
a second filter that transmits the first light reflected by the first filter, reflects the second light, and multiplexes the first light and the second light;
The second filter transmits the first combined light, which is the combined light of the first light and the second light, and reflects the third light, thereby forming the first combined light and the second combined light. a third filter that combines the light of No. 3;
a fourth filter that reflects the fourth light;
transmitting a second combined light that is a combined light of the first combined light and the third light combined by the third filter, and reflecting the fourth light reflected by the fourth filter; a splitter that combines the second combined light and the fourth light,
The base portion includes a block portion disposed in contact with the first surface and on which the mount portion is placed,
4. A side surface of the block portion on the mirror drive mechanism side is closer to the mirror drive mechanism than a position where the second combined light and the fourth light are combined in the splitter. The optical module described.

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