Optical Module

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

[Technical Field]

[0001] The present disclosure relates to optical modules. [Background technology]

[0002] Optical modules that combine and output laser beams have been disclosed (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-77711 [Patent Document 2] International Publication No. 2021 / 166466 Summary of the Invention [Problem to be solved by the invention]

[0004] Optical modules using laser diodes may be equipped with a mirror drive mechanism that scans and emits light emitted from the laser diode. Such optical modules are used in projectors that scan emitted laser light to project images, and distance sensors that scan laser light and capture light reflected from an object with a photodetector to sense the presence or distance of an object. The laser diode may emit visible light or infrared light, for example. Recently, there has been a demand for miniaturization of devices that can project high-quality images and perform high-resolution sensing. As a result, there has also been a demand for miniaturization of the optical modules installed in such devices.

[0005] Therefore, one of the objectives is to provide an optical module that makes it easy to miniaturize the devices in which it is installed, such as projectors and distance measuring sensors, and to improve the image quality of projected images and images obtained by sensing. [Means for solving the problem]

[0006] An optical module according to the present disclosure includes a base including a support plate having a first surface, a first laser diode attached to the base, a reflecting mirror that reflects first light emitted from the first laser diode, a mirror drive mechanism that is attached to the base and includes a scanning mirror that scans the first light reflected by the reflecting mirror, and a reflecting mirror support attached to the base so as to extend from the base and support the reflecting mirror. A side surface of the reflecting mirror is attached to a side surface of the reflecting mirror support that is perpendicular to the first surface. [Effects of the Invention]

[0007] Such an optical module makes it easy to miniaturize the device in which it is installed, 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. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an external perspective view showing the structure of an optical module according to a first embodiment. [Figure 2] FIG. 2 is an external perspective view showing a state in which a cap, which will be described later, of the optical module shown in FIG. 1 is removed. [Figure 3] FIG. 3 is a schematic plan view of the optical module shown in FIG. [Figure 4] FIG. 4 is a schematic side view of the optical module shown in FIG. [Figure 5] FIG. 5 is a schematic side view of the optical module shown in FIG. [Figure 6] FIG. 6 is an enlarged view showing a part of the optical module shown in FIG. [Figure 7] FIG. 7 is a schematic plan view of a mirror driving mechanism included in the optical module. [Figure 8] FIG. 8 is an external perspective view showing a state in which the cap of the optical module according to the second embodiment is removed. [Figure 9] FIG. 9 is a schematic plan view of the optical module shown in FIG. [Figure 10] FIG. 10 is a schematic side view of the optical module shown in FIG. [Figure 11] FIG. 11 is a schematic side view showing a cross section of a cap in an optical module according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] [Description of the embodiments of the present disclosure] First, embodiments of the present disclosure will be listed and described. (1) A laser diode includes a base including a support plate having a first surface, a first laser diode attached to the base, a reflecting mirror that reflects first light emitted from the first laser diode, a mirror drive mechanism that includes a scanning mirror attached to the base and that scans the first light reflected by the reflecting mirror, and a reflecting mirror support attached to the base so as to extend from the base and support the reflecting mirror. A side of the reflecting mirror is attached to a side of the reflecting mirror support that is perpendicular to the first surface.

[0010] In this optical module, the first light emitted from the first laser diode passes through the focusing / combining optical system, is reflected by the reflecting mirror, and then enters the scanning mirror included in the mirror drive mechanism. To suppress scanning distortion of the laser light 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 from the scanning mirror, preferably within 40°. In conventional configurations, the first light emitted from the first laser diode passes through the focusing / combining optical system and then directly enters the scanning mirror. Therefore, when the angle between the incident light and the reflected light on the scanning mirror surface is reduced to within 40°, interference easily occurs between the components constituting the focusing / combining optical system and the scanning mirror. Therefore, increasing the distance between the components constituting the focusing / combining optical system and the scanning mirror avoids interference, but this increases the size of the optical module. On the other hand, the optical module according to the present disclosure allows for a larger angle between the incident light and the reflected light on the scanning mirror surface. As a result, even if the distance between the components constituting the focusing / combining optical system and the scanning mirror is shortened, interference between the components constituting the focusing / combining optical system and the reflected light from the scanning mirror surface can be prevented, allowing for a more compact optical module. Furthermore, when a conventional optical module and an optical module according to the present disclosure have the same size, the optical module according to the present disclosure makes it easier to secure a larger mounting space for the focusing optical system. As a result, it is easier to use a lens with a long focal length that requires a longer distance between the laser diode and the lens, or to reduce the beam diameter of collimated light. This allows for higher image quality in projectors and ranging sensors with a beam diameter of one pixel to project and sense images.

[0011] A typical method for fixing a reflecting mirror is to construct a reflecting mirror support member with a surface parallel to the first surface, and attach the side of the reflecting mirror to that surface. However, during actual manufacturing, the center of the reflecting mirror and the center of the incident light inevitably deviate from the design, so a margin must be built into the size of the reflecting mirror. This requires a larger size of the optical module to prevent interference between the scanned laser light and the reflecting mirror. On the other hand, the optical module disclosed herein can detect deviations in the center of the reflecting mirror from the design, and precisely adjust and fix both the position and angle of the reflecting mirror. As a result, the size of the reflecting mirror can be minimized relative to the beam diameter of the incident light, allowing for a more compact optical module.

[0012] However, if the reflecting mirror is made smaller, it becomes difficult to adjust the position of the reflecting mirror so that the first light emitted from the first laser diode is appropriately incident and reflected toward the position of the scanning mirror. According to the optical module of the present disclosure, the side of the reflecting mirror is attached to the side of the reflecting mirror support section, which is perpendicular to the first surface. This makes it easy to finely adjust the angle and position of the reflecting mirror, taking into account the optical axis of the first light emitted from the first laser diode and the scanning direction of the first light scanned by the scanning mirror. Therefore, an optical module with such a configuration facilitates miniaturization of the device in which it is installed, such as a projector or a ranging sensor, and high image quality of projected images and images obtained by sensing.

[0013] (2) In the above (1), the base portion may include an electronic cooling module having a heat sink, a heat absorption plate, and a plurality of semiconductor pillars connecting the heat sink and the heat absorption plate. The first laser diode and the mirror drive mechanism may be attached to the heat absorption plate. This allows the temperature of the first laser diode and the mirror drive mechanism to be adjusted according to the environmental temperature. This allows for stable light output and stable deflection angle of the scanning mirror. As a result, highly reproducible projection and sensing are possible, making it easier to achieve higher image quality.

[0014] (3) In the above (1) or (2), the optical component adjusting the first light emitted from the first laser diode may be further included. The base portion may include a pedestal disposed at a distance from the first surface and on which the mirror drive mechanism is mounted; a base plate disposed at a distance from the first surface and on which the optical component is mounted; and a mount disposed at a distance from the base plate and on which the first laser diode is mounted. 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 may increase in this order. The first laser diode generates heat during operation. This allows the first laser diode to be positioned at a high position and away from the optical component and the mirror drive mechanism, thereby minimizing the effect of heat generated by the first laser diode on the optical component disposed on the base plate and the mirror drive mechanism disposed on the pedestal. This maintains stable operation of the mirror drive mechanism, enabling highly reproducible projection and sensing, thereby facilitating higher image quality.

[0015] (4) In any of (1) to (3) above, the reflecting mirror support may include a first region provided in contact with the base and a second region at least partially overlapping with the mirror drive mechanism when viewed in a direction perpendicular to the first surface. The side of the reflecting mirror may be attached to a side of the second region perpendicular to the first surface of the base. This facilitates fine adjustment of the angle and position of the reflecting mirror while further compactifying the device configuration and reduces loss of light that deviates from the designed optical path, making it easier to achieve higher image quality.

[0016] (5) In any of (1) to (3) above, the reflecting mirror support may include a first region and a third region that are provided in contact with the base, and a second region that at least partially overlaps with the mirror drive mechanism when viewed in a direction perpendicular to the first surface. The second region may be provided so as to connect the first region and the third region across the mirror drive mechanism. The second region may include a cutout. A side surface of the reflecting mirror may be attached to the cutout. This makes it easy to properly attach the reflecting mirror using the cutout in the second region. In this case, it is possible to reduce the risk that portions of the reflecting mirror support other than the portion where the reflecting mirror is attached will block the optical path. Therefore, it is possible to more efficiently achieve a compact device configuration.

[0017] (6) In any of the above (1) to (5), the mirror drive mechanism may be attached so that the reflective surface of the scanning mirror is parallel to the first surface. This facilitates attachment of the mirror drive mechanism and simplifies the device configuration, making it easier to reduce costs.

[0018] (7) In the above (4), the side surface of the second region may be an end portion of the reflecting mirror support portion, and the reflecting surface of the scanning mirror may be inclined with respect to the optical axis of the first light emitted from the first laser diode. This makes it possible to make the device configuration more compact and easily adjust the emission direction of the light emitted by the optical module as desired.

[0019] (8) In any of the above (3) to (7), 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.

[0020] (9) In any of (3) to (8) above, the optical module may further include a second laser diode attached to the base portion and emitting second light having a wavelength different from that of 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 so, light obtained by combining the first light emitted from the first laser diode and the second light emitted from the second laser diode can be emitted from the optical module.

[0021] (10) In any of the above (3) to (9), the distance between the mirror drive mechanism and the base plate may be 1 mm or less. This allows the base plate to be as wide as possible, facilitating heat diffusion. Therefore, the effects of heat generation can be reduced, and even if the vibration characteristics of the mirror drive mechanism fluctuate due to temperature fluctuations, stable operation of the mirror drive mechanism can be maintained, making it easier to achieve higher image quality.

[0022] (11) In any of (3) to (10) above, the optical module may include a second laser diode arranged in contact with the mount portion and emitting a second light of a color different from the color of the first light, a third laser diode arranged in contact with the mount portion and emitting a third light of a color different from both the color of the first light and the color of the second light, and a fourth laser diode emitting a fourth light of the same color as the color of the first light. The optical component may include a first filter that reflects first light, a second filter that transmits the first light reflected by the first filter and reflects the second light to combine the first light and the second light, a third filter that transmits first combined light, which is combined light of the first light and the second light combined by the second filter, and reflects third light to combine the first combined light and the third light, a fourth filter that reflects fourth light, and a splitter that transmits second combined light, which is combined light of the first combined light and the third light combined by the third filter, and reflects the fourth light reflected by the fourth filter to combine the second combined light and the fourth light. The base may include a block that is disposed in contact with the first surface and on which the mount is placed. A side of the block that faces the mirror drive mechanism may be closer to the mirror drive mechanism than a position in the splitter where the second combined light and the fourth light are combined. This allows the block section to be positioned closer to the mirror drive mechanism, and the heat generated by each laser diode can be transferred to the wider block section, facilitating thermal diffusion. This prevents the temperature of the mirror drive mechanism from fluctuating due to the heat generated by each laser diode changing when it is turned on or off, maintaining stable operation of the mirror drive mechanism and facilitating higher image quality.

[0023] [Details of the embodiments of the present disclosure] Next, an embodiment of an optical module according to the present disclosure will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference characters, and the description thereof will not be repeated.

[0024] (Embodiment 1) An optical module according to a first embodiment 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 showing 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. FIGS. 4 and 5 are schematic side views of the optical module shown in FIG. 2. FIG. 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 portion of the optical module shown in FIG. 4.

[0025] 1, 2, 3, 4, 5, and 6, an optical module 10a includes a base portion 11, a cap 12 as a protective member, multiple laser diodes, multiple optical components, a mirror drive mechanism 50 including a scanning mirror 52 that scans light, a reflection mirror 67 that reflects light, and a reflection mirror support portion 70a that supports the reflection mirror 67. In this embodiment, the base portion 11 includes a flat support plate 13, a flat base plate 14, an electronic cooling module 30, block portions (first block portion 17a, second block portion 17b), and multiple mount portions (first mount portion 18a, second mount portion 18b, third mount portion 18c, fourth mount portion 18d, fifth mount portion 18e). The cap 12 is a lid welded to the support plate 13. Components arranged 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, with four rounded corners. Specifically, the support plate 13 is configured so that the length in the X direction is longer than the length in the Y direction.

[0026] 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 perpendicular to the Z direction, i.e., parallel to the XY plane. The cap 12 is disposed in contact with the first surface 13a. The cap 12 is provided with an exit window 15 that transmits light. The multiple laser diodes and multiple optical components, the mirror drive mechanism 50, the reflecting mirror 67, and the reflecting mirror support portion 70a arranged on the support plate 13 are hermetically sealed by the cap 12. The exit window 15 is provided on the upper side of the cap 12, i.e., in 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 installed on 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.

[0027] 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 perpendicular to the Z direction, i.e., parallel to the XY plane.

[0028] The electronic cooling module 30 adjusts the temperature of each component thereon. The electronic cooling module 30 is also called a TEC (Thermo-Electric Cooler) and includes a heat sink 31, a heat absorption plate 32, and a plurality of semiconductor pillars 33. The electronic cooling module 30 is disposed on a support plate 13, specifically on a first surface 13a of the support plate 13. The base plate 14 is disposed on the electronic cooling module 30. That is, the electronic cooling module 30 is disposed 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 disposed so as to be in contact with the first surface 13a of the support plate 13. The heat absorption plate 32 is disposed so as to be in contact with a second main surface 14b of the base plate 14. The support plate 13 and the heat sink 31, and the base plate 14 and the heat absorption plate 32 are each bonded by a bonding material (not shown). The multiple semiconductor pillars 33 are made up of Peltier elements and are arranged between the heat sink 31 and the heat absorption plate 32 at intervals in the X and Y directions. The multiple semiconductor pillars 33 are connected to the heat sink 31 and the heat absorption plate 32, respectively. By applying electricity to the electronic cooling module 30, the temperature of each component on the electronic cooling module 30 can be adjusted. Adjusting the current supplied to the electronic cooling module 30 makes it easy to maintain the temperature of each component on the electronic cooling module 30 constant over the long term, specifically, for example, at 35°C.

[0029] 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 disposed on the first main surface 14a of the base plate 14. When viewed in the Z direction, the first block portion 17a is configured so that its length in the X direction is longer than its length in the Y direction. When viewed in the Z direction, the second block portion 17b is configured so that its length in the Y direction is longer than its length in the X direction. The first mount portion 18a, the second mount portion 18b, and the third mount portion 18c included in the base portion 11 are disposed in contact with the first block portion 17a. The first mount portion 18a, the second mount portion 18b, and the third mount portion 18c are disposed on the first block portion 17a as shown in FIG. 2 and other figures. The fourth mount portion 18d and the fifth mount portion 18e included in the base portion 11 are disposed in contact with the second block portion 17b. The fourth mount portion 18d and the fifth mount portion 18e are arranged on the second block portion 17b as shown in FIG. 2 etc. The first mount portion 18a, the second mount portion 18b, and the third mount portion 18c are arranged side by side at intervals in the direction opposite to the arrow X. The fourth mount portion 18d and the fifth mount portion 18e are arranged at intervals in the direction opposite to the arrow Y. The base portion 11 includes a partition plate 19 arranged 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.

[0030] 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 a first light L1 that is red light. The second laser diode 41b emits a second light L2 that is green light. The third laser diode 41c emits a third light L3 that is blue light. The fourth laser diode 41d emits a fourth light L4 that is red light. The fifth laser diode 41e emits a fifth light L5 that is green light.

[0031] The first laser diode 41a is mounted on the first mount 18a. The first laser diode 41a emits a first light L1 in the Y direction (the direction of the arrow Y). The second laser diode 41b is mounted on the second mount 18b. The second laser diode 41b emits a second light L2 in the Y direction (the direction of the arrow Y). The third laser diode 41c is mounted on the third mount 18c. The third laser diode 41c emits a third light L3 in the Y direction (the direction of the arrow Y). The fourth laser diode 41d is mounted on the fourth mount 18d. The fourth laser diode 41d emits a fourth light L4 in the X direction (the direction opposite to the arrow X). The fifth laser diode 41e is mounted on the fifth mount 18e. The fifth laser diode 41e emits a fifth light L5 in the X direction (the direction opposite to the arrow X). Here, the first laser diode 41a and the fourth laser diode 41d, which emit red light, have relatively high temperature dependence. Furthermore, the second laser diode 41b and the fifth laser diode 41e, which emit green light, generate a large amount of heat during operation. As described above, by placing the second laser diode 41b next to the first laser diode 41a and the fifth laser diode 41e next to the fourth laser diode 41d, the first laser diode 41a and the fourth laser diode 41d can be positioned equidistant from the second laser diode 41b and the fifth laser diode 41e, which generate a large amount of heat, respectively, thereby suppressing temperature fluctuations in the first laser diode 41a and the fourth laser diode 41d. This facilitates uniform temperature distribution and stabilizes the output from each laser diode.

[0032] The optical module 10a includes a plurality of lenses (first lens 42a, second lens 42b, third lens 42c, fourth lens 42d, and fifth lens 42e) as optical components. The first lens 42a, second lens 42b, third lens 42c, fourth lens 42d, and fifth lens 42e are each placed above the heat absorption plate 32, specifically on the first main surface 14a of the base plate 14. The first lens 42a, second lens 42b, third lens 42c, fourth lens 42d, and fifth lens 42e convert the spot sizes of light emitted from the first laser diode 41a, second laser diode 41b, third laser diode 41c, fourth laser diode 41d, and fifth laser diode 41e, respectively. Specifically, each lens is disposed in the direction of emission of light from each laser diode and converts the light emitted from each laser diode into collimated light. In this way, each lens conditions the light emitted from each laser diode.

[0033] 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 placed above the heat absorption plate 32, specifically on the first main surface 14a of the base plate 14. The first filter 43a, the second filter 43b, the third filter 43c, the fourth filter 43d, and the fifth filter 43e are arranged in the emission directions of the 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, respectively. The first filter 43a reflects the first light L1 in the X direction (the direction opposite to the arrow X). The second filter 43b transmits the first light L1 and reflects the second light L2 in the X direction (the direction opposite to the arrow X). In this way, the first light L1 and the second light L2 are multiplexed. The third filter 43c multiplexes the first light L1 and the second light L2 into the first multiplexed light L2. X The first multiplexed light L1 is transmitted through the first multiplexed light L2 and the third multiplexed light L3 is reflected in the X direction (the direction opposite to the arrow X).X The first multiplexed light L1 and the third light L2 are multiplexed. X and the third light L3 are multiplexed to form a second multiplexed light L Y The fourth light L4 travels in the X direction (the opposite direction to the arrow X). The fourth filter 43d reflects the fourth light L4 in the Y direction (the opposite direction to the arrow Y). The fifth filter 43e transmits the fourth light L4 and reflects the fifth light L5 in the Y direction (the opposite direction to the arrow Y). In this way, the fourth light L4 and the fifth light L5 are multiplexed.

[0034] 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 placed above the heat absorption plate 32, specifically on the first main surface 14a of the base plate 14. The half-wave plate 44 splits the fourth light L4 and the fifth light L5 into a third combined light L5. Z The half-wave plate 44 is disposed in the direction of travel of the third multiplexed light L Z The half-wave plate 44 rotates the polarization direction of the second multiplexed light L by 90 degrees. Y The polarization direction of the first light L1 and the third multiplexed light L Z The polarization direction of the fourth light L4 is perpendicular to the polarization direction of the second multiplexed light L5. Y The polarization direction of the second light L2 and the third combined light L Z The polarization direction of the second combined light L1 is perpendicular to the polarization direction of the fifth light L5. The beam splitter 45 is polarization-dependent. The beam splitter 45 has a cube shape. The beam splitter 45 splits the second combined light L2 into Y and the third multiplexed light L Z In this way, the second multiplexed light L Y and the third multiplexed light L Z and the fourth combined light L W The fourth multiplexed light L travelling in the X direction (opposite to the arrow X) is obtained. W The fourth combined light L is a light obtained by combining two red light beams, two green light beams, and one blue light beam, and can achieve high output. W The fourth multiplexed light L passes through a through hole 20 provided in the partition plate 19 and travels in the X direction (the opposite direction to the arrow X).W is used to draw a projected image by the mirror drive mechanism 50. The side surface of the first block portion 17a on the side of the mirror drive mechanism 50 is used to split the second combined light L Y The first light beam L1 and the fourth light beam L2 are configured closer to the mirror drive mechanism 50 than the position where the first light beam L1 and the fourth light beam L2 are combined.

[0035] The optical module 10a includes a first thermistor 21a and a second thermistor 21b. The first thermistor 21a is disposed on a base portion 22 that is disposed on the first surface 13a of the support plate 13. The base portion 22 is disposed adjacent to the heat sink 31. The first thermistor 21a can be used to detect the temperature of the support plate 13. The second thermistor 21b is disposed on the first block portion 17a. The second thermistor 21b is disposed near the second laser diode 41b. The second thermistor 21b can be used to detect the temperature of the first block portion 17a, and therefore the region on the heat absorption plate 32. The temperatures detected by the first thermistor 21a and the second thermistor 21b are used for temperature adjustment by the electronic cooling module 30.

[0036] The mirror drive mechanism 50 included in the optical module 10a is disposed 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 the figures other than Fig. 7, the illustration of the mirror drive mechanism 50 is simplified.

[0037] Referring also to FIG. 7, mirror drive mechanism 50 includes frame 51, disk-shaped scanning mirror 52 having reflecting surface 55, and support 53 that supports scanning mirror 52. Scanning mirror 52 is configured to be able to swing about first and second swing axes 59a and 59b, each indicated by a dashed line. First swing axis 59a is a virtual axis extending along direction D2 in FIG. 7, and second swing axis 59b is a virtual axis extending along direction D1 in FIG. 7. Directions D1 and D2 are orthogonal to each other. Note that, when assembling optical module 10a, the direction in which mirror drive mechanism 50 is attached is the direction indicated by arrow D1, which is the direction indicated by arrow X in FIG. 1, etc., and the direction indicated by arrow D2, which is the direction indicated by arrow Y in FIG. 1, etc.

[0038] A first through-hole 57a is provided in the frame 51, and a support 53 is provided in the first through-hole 57a to support the scan mirror 52. A second through-hole 57b is provided in the support 53, and the scan mirror 52 is supported in the second through-hole 57b by a pair of thin rod-shaped shafts 54a and 54b so as to be able to swing about a second oscillation axis 59b indicated by a dashed line. When the scan mirror 52 swings about the second oscillation axis 59b, four piezoelectric elements 56a, 56b, 56c, and 56d attached to the support 53 are utilized.

[0039] The support portion 53 is plate-shaped and includes a plurality of first portions 61a, 61b, 61c, 61d, 61e, 61f, 61g, and 61h each extending along the D1 direction, a plurality of second portions 62a, 62b, 62c, 62d, 62e, and 62f connecting adjacent first portions 61a to 61h, connecting portions 63a and 63b connecting the support portion 53 to the frame portion 51, an attachment portion 58 to which the scan mirror 52 is attached via shafts 54a and 54b, and connecting portions 63c and 63d connecting the first portions 61d and 61h to the attachment portion 58. The second portions 62a to 62f alternately connect ends on one side and ends on the other side in the longitudinal direction of adjacent first portions 61a to 61h. When the scanning mirror 52 oscillates around the first oscillation axis 59a, the support portion 53, specifically, the piezoelectric elements 64a, 64b, 64c, 64d, 64e, 64f, 64g, and 64h attached to the first portions 61a to 61h, are utilized. The piezoelectric elements 56a to 56d and 64a to 64h may be, for example, piezo elements. The support portion 53 has a so-called meander structure.

[0040] The mirror drive mechanism 50 adjusts the voltages supplied to the piezoelectric elements 56a to 56d and 64a to 64h, and swings the scanning mirror 52 about the first swing shaft 59a and the second swing shaft 59b, respectively.

[0041] The base unit 11 includes pedestals 65a and 66a. The pedestals 65a and 66a are each rod-shaped and extend in the Y direction. The pedestals 65a and 66a are spaced apart in the X direction and arranged on the base unit 11, specifically on the heat absorption plate 32. The mirror drive mechanism 50 is placed on the pedestals 65a and 66a. In this embodiment, the pedestals 65a and 66a have the same height in the Z direction, and the reflecting 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 oscillating. A gap is formed between the mirror drive mechanism 50 and the heat absorption plate 32.

[0042] Here, if the height from the first surface 13a to the pedestals 65a, 66a is defined as height H1, the height from the first surface 13a to the base plate 14 is defined as height H2, and the height from the first surface 13a to the first to fifth mount portions 18a to 18e is defined as height H3, the heights increase in this order from height H1 to height H2 to height H3. Also, 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.

[0043] The reflecting mirror 67 included in the optical module 10a includes a reflecting surface 68 that reflects light and a side surface 69 that is continuous with and intersects with the reflecting surface 68. The reflecting surface 68 is a flat surface. The outer shape of the reflecting mirror 67 is rectangular when viewed in a direction perpendicular to the reflecting surface 68.

[0044] The reflecting mirror support part 70a included in the optical module 10a supports the reflecting mirror 67. The reflecting mirror support part 70a is disposed on the electronic cooling module 30, specifically on the heat absorption plate 32. The reflecting mirror support part 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 part 11, specifically on the heat absorption plate 32. The second region 72a overlaps with the mirror drive mechanism 50 when viewed in the direction perpendicular to the first surface 13a (Z direction). The second region 72a is provided to connect the first region 71a and the third region 73 across the mirror drive mechanism 50.

[0045] The second region 72a includes a cutout portion 74. The cutout portion 74 is provided so that the height from the first surface 13a on the first region 71a side is greater 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 reflecting mirror support portion 70a. The side surface 75a is a side surface perpendicular to the first surface 13a.

[0046] Here, the reflecting mirror 67 is attached to the reflecting mirror support portion 70a. Specifically, a side surface 69 of the reflecting mirror 67 is attached to a side surface 75a of the reflecting mirror support portion 70a. When attaching the reflecting mirror 67, an adhesive is used to fix the fourth multiplexed light L W The position of the optical axis of the scanning mirror 52 and the center position of the reflecting surface 55 of the scanning mirror 52 are taken into consideration, and the adjustment is made minutely.

[0047] Next, the projection of an image by the optical module 10a and the irradiation of sensing light onto an object will be described. 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 output from the beam splitter 45 as the fourth multiplexed light L. W Then, the fourth multiplexed light L W The combined light passes through the through hole 20 of the partition plate 19 and reaches the reflecting mirror 67. The combined light that reaches the reflecting mirror 67 is reflected by the reflecting surface 68 of the reflecting mirror 67 and travels along the optical path L U and is incident on a scanning mirror 52 included in a mirror driving mechanism 50. The combined light incident on the scanning mirror 52 is reflected by a 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.

[0048] Here, the scanning mirror 52 is oscillated at high speed around a first oscillation axis 59a and a second oscillation axis 59b that are orthogonal to each other by the mirror driving mechanism 50. Therefore, the combined light that is reflected by the reflecting surface 68 of the reflecting mirror 67 and incident on the scanning mirror 52 is reflected by the reflecting surface 55 of the scanning mirror 52, which is the scanning mirror surface, and moves along the optical axis L due to the oscillation of the first oscillation axis 59a and the second oscillation axis 59b. T The optical path L is defined by the angle θ1. S and the optical path L R The light is emitted within the range of 10a and is used to draw an image or emit sensing light outside the optical module 10a.

[0049] According to the optical module 10a of the present disclosure, the combined light including the first light L1 emitted from the first laser diode 41a is not directly incident on the scanning mirror 52. This allows for greater design latitude in consideration of the projection of an image by the scanning mirror 52, making it easier to achieve compactness. Furthermore, the scanning mirror 52 can be positioned relatively far from the emission position of the first laser diode 41a, thereby reducing the beam diameter at the focusing position (the imaging position), thereby achieving high image quality. In this case, in order to achieve compactness of the device, it is also easy to achieve a compact 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.

[0050] Furthermore, according to the optical module 10a of the present disclosure, the side surface 69 of the reflecting mirror 67 is configured to be attached to the side surface 75a of the reflecting mirror support portion 70a, which is perpendicular to the first surface 13a, and therefore it is easy to finely adjust the angle and position of the reflecting mirror 67 in consideration of the optical axis of the combined light including the first light emitted from the first laser diode 41a and the scanning direction of the combined light including the first light scanned by the scanning mirror 52. Therefore, according to the optical module 10a configured in this manner, it is easy to miniaturize the device in which it is installed, such as a projector or a distance measuring sensor, and to improve the image quality of the projected image and the image obtained by sensing.

[0051] In this embodiment, the base portion 11 includes an electronic cooling module 30 having a heat sink 31, a heat absorption plate 32, and a plurality of semiconductor pillars 33 connecting the heat sink 31 and the heat absorption plate 32. Each laser diode and mirror drive mechanism 50 is attached to the heat absorption plate 32. This allows the temperature of each laser diode, including the first laser diode 41a, and the mirror drive mechanism 50 to be adjusted according to the ambient temperature. This allows for stable light output and stabilizes the deflection angle of the scanning mirror 52. As a result, highly reproducible projection and sensing are possible, making it easier to achieve higher image quality.

[0052] In this embodiment, the base portion 11 includes pedestals 65a and 66a that are spaced apart from the first surface 13a and that mount the mirror drive mechanism 50, a base plate 14 that is spaced apart from the first surface 13a and that mounts optical components thereon, and mounts 18a, 18b, 18c, 18d, and 18e that are spaced apart from the base plate 14 and that mount the laser diodes 41a, 41b, 41c, 41d, and 41e. The heights increase in order of height H1 from the first surface 13a to the pedestals 65a and 66a, height H2 from the first surface 13a to the base plate 14, and height H3 from the first surface 13a to the mounts 18a to 18e. Each laser diode generates heat during operation, but by doing so, each laser diode can be placed in a high position and away from the optical components and mirror drive mechanism 50, thereby reducing as much as possible the effect of heat generated by each laser diode on the optical components arranged on base plate 14 and mirror drive mechanism 50 arranged on pedestals 65a, 66a. Therefore, stable operation of mirror drive mechanism 50 can be maintained, enabling projection and sensing with high reproducibility, making it easier to achieve higher image quality.

[0053] In this embodiment, the reflecting mirror support portion 70a includes a first region 71a and a third region 73 that are provided in contact with the heat absorption plate 32, and a second region 72a that overlaps with the mirror drive mechanism 50 when viewed in a direction perpendicular to the first surface 13a. The second region 72a is provided to connect the first region 71a and the third region 73 across the mirror drive mechanism 50. The second region 72a includes a notch 74. The side surface 69 of the reflecting mirror 67 is attached to the notch 74. Therefore, the notch 74 in the second region 72a can be used to easily attach the reflecting mirror 67 appropriately. This reduces the risk that portions of the reflecting mirror support portion 70a other than the portion where the reflecting mirror 67 is attached will block the optical path. Therefore, while the device configuration can be made more efficiently compact, it becomes easier to finely adjust the angle and position of the reflecting mirror 67, and the loss of light that deviates from the designed optical path can be reduced, making it easier to achieve higher image quality.

[0054] 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. This reduces the effects of heat generation, and therefore, even if the vibration characteristics of the mirror drive mechanism 50 fluctuate due to temperature fluctuations in the mirror drive mechanism 50, stable operation of the mirror drive mechanism 50 can be maintained, making it easier to achieve higher image quality.

[0055] In this embodiment, the side surface of the first block portion 17a on the side of the mirror driving mechanism 50 is a beam splitter 45 for splitting the second combined light L Y and the fourth light L4 are multiplexed. This makes it possible to suppress fluctuations in the temperature of the mirror drive mechanism 50, which would otherwise be caused by fluctuations in the amount of heat generated by each laser diode depending on whether the laser diode is turned on or off, thereby maintaining stable operation of the mirror drive mechanism 50 and achieving higher image quality.

[0056] (Embodiment 2) Another embodiment, embodiment 2, will now be described. FIG. 8 is an external perspective view showing the optical module according to embodiment 2 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 of the optical module according to embodiment 2, showing the cap in cross section. FIG. 11 is a side view seen from the direction opposite to arrow Y. The optical module according to embodiment 2 basically has the same configuration as embodiment 1, and achieves the same effects. However, the optical module according to embodiment 2 differs from embodiment 1 in the configuration for attaching the mirror drive mechanism and the configuration of the reflecting mirror support section.

[0057] 8 to 11, a reflecting mirror support part 70b included in an optical module 10b according to the second embodiment includes a first region 71b provided in contact with the base part 11, specifically, the heat absorption plate 32, and a second region 72b overlapping with the mirror drive mechanism 50 when viewed in a direction perpendicular to the first surface 13a. A side surface 69 of the reflecting mirror 67 is attached to a side surface 75b of the second region 72b that is perpendicular to the first surface 13a.

[0058] Furthermore, the base 65b included in the optical module 10b in the second embodiment is configured from a single triangular prism-shaped member. In this case, the mounting surface on which the mirror driving mechanism 50 is mounted is inclined with respect to the first surface 13a. That is, the reflecting surface 55 of the scanning mirror 52 reflects the fourth combined light L1, which includes the first light L1 emitted from the first laser diode 41a. W The optical axis of the optical system is inclined.

[0059] In the optical module 10b, the reflecting mirror support portion 70b includes a first region 71b that is 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. The side surface 69 of the reflecting mirror 67 is attached to a side surface 75b in the second region 72b that is perpendicular to the first surface 13a. This makes it easier to achieve high image quality while further reducing the size of the device configuration.

[0060] In this embodiment, the side surface 75b of the second region 72b is an end portion of the reflecting mirror support portion 70b, and the reflecting surface 55 of the scanning mirror 52 is inclined with respect to the optical axis of the combined light including the optical axis of the first light L1 emitted from the first laser diode 41a. Therefore, the emission direction of the light emitted by the optical module 10b can be easily adjusted as desired while making the device configuration more compact.

[0061] (Other embodiments) In the above embodiment, the base unit includes an electronic cooling module, but this is not limiting, and the base unit may be configured not to include an electronic cooling module. In this case, for example, the first block unit or the like may be placed on the support plate.

[0062] Furthermore, 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; however, this is not limited to this, and the optical module may include, for example, only three laser diodes: a first laser diode, a second laser diode, and a third laser diode, or may include any number of laser diodes, or may include only one laser diode.

[0063] It should be understood that the embodiments disclosed herein are illustrative in all respects and are not limiting in any respect. The scope of the present invention is defined not by the above description but by the claims, and it is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0064] 10a, 10b Optical module 11 Base 12 Caps 13 Support plate 13a First Side 13b Second Side 14 Base plate 14a First principal surface 14b Second main surface 15 Exit window 16 lead pin 17a Block section (first block section) 17b Block section (second block section) 18a Mounting section (first mounting section) 18b Mounting section (second mounting section) 18c Mounting section (third mounting section) 18d Mounting section (4th mounting section) 18e Mounting section (5th mounting section) 19 Partition 20 through holes 21a First thermistor 21b Second thermistor 22 Base 30 Electronic Cooling Module 31 Heat sink 32 Heat absorption plate 33 Semiconductor Pillar 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 52 Scanning mirror 53 Support part 54a,54b Shaft part 55,68 reflective surface 56a, 56b, 56c, 56d, 64a, 64b, 64c, 64d, 64e, 64f, 64g, 64h Piezoelectric elements 57a 1st through hole 57b 2nd through hole 58 Mounting part 59a First swing shaft 59b Second swing shaft 61a,61b,61c,61d,61e,61f,61g,61h 1st part 62a,62b,62c,62d,62e,62f 2nd part 63a,63b connection part 63c,63d connection part 65a, 65b, 66a pedestal 67 Reflective mirror 69,75a,75b side 70a, 70b Reflection mirror support portion 71a,71b 1st area 72a,72b 2nd area 73 Third area 74 Notch L1 First Light L2 Second Light L3 Third Light L4 The Fourth Light L5 The Fifth Light L X First combined light L Y Second combined light L Z Third combined light L W 4th combined light H1, H2, H3 height S distance

Claims

1. a base including a support plate having a first surface; a first laser diode attached to the base portion; a reflecting mirror that reflects the first light emitted from the first laser diode; a mirror driving mechanism attached to the base portion and including a scanning mirror that scans the first light reflected by the reflecting mirror; a reflecting mirror support portion attached to the base portion so as to extend from the base portion and supporting the reflecting mirror, An optical module, wherein a side surface of the reflecting mirror is attached to a side surface of the reflecting mirror support part that is perpendicular to the first surface.

2. the base portion includes an electronic cooling module having a heat dissipation plate, a heat absorption plate, and a plurality of semiconductor pillars connecting the heat dissipation plate and the heat absorption plate; The optical module according to claim 1 , wherein the first laser diode and the mirror driving mechanism are attached to the heat absorption plate.

3. an optical component for adjusting the first light emitted from the first laser diode; The base portion is a base disposed at an interval from the first surface and on which the mirror drive mechanism is placed; a base plate disposed at an interval 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 mounted, 3. The optical module according to claim 1, wherein the height from the first surface to the base increases in the order of height from the first surface to the base plate and height from the first surface to the mount portion.

4. The reflecting mirror support portion is a first region provided in contact with the base portion; a second region at least partially overlapping with the mirror drive mechanism when viewed in a direction perpendicular to the first surface; 3. The optical module according to claim 1, wherein a side surface of the reflecting mirror is attached to a side surface of the base portion that is perpendicular to the first surface in the second region.

5. The reflecting mirror support portion is a first region and a third region provided in contact with the base portion; a second region at least partially overlapping with the mirror drive mechanism when viewed in a direction perpendicular to the first surface; the second area is provided so as to connect the first area and the third area across the mirror drive mechanism, the second region includes a cutout portion, 3. The optical module according to claim 1, wherein a side surface of the reflecting mirror is attached to the notch.

6. 3. The optical module according to claim 1, wherein the mirror driving mechanism is attached so that a reflecting surface of the scanning mirror is parallel to the first surface.

7. the side surface of the second region is an end portion of the reflecting mirror support portion, 5. The optical module according to claim 4, wherein the reflecting surface of the scanning mirror is provided at an angle with respect to the optical axis of the first light emitted from the first laser diode.

8. 4. 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.

9. a second laser diode attached to the base portion and emitting a second light beam having a wavelength different from that of the first light beam; 4. The optical module 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.

10. 4. The optical module according to claim 3, wherein the distance between the mirror drive mechanism and the base plate is 1 mm or less.

11. a second laser diode disposed in contact with the mount portion and configured to emit a second light having a color different from the color of 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; a fourth laser diode that emits a fourth light having 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 and reflects the second light to combine the first light and the second light; a third filter that transmits first multiplexed light, which is multiplexed light of the first light and the second light multiplexed by the second filter, and reflects the third light, thereby multiplexing the first multiplexed light and the third light; a fourth filter that reflects the fourth light; a splitter that transmits second multiplexed light that is multiplexed light of the first multiplexed light and the third light multiplexed by the third filter, and reflects the fourth light that is reflected by the fourth filter, thereby multiplexing the second multiplexed light and the fourth light, the base portion includes a block portion that is disposed in contact with the first surface and on which the mount portion is placed; 4. The optical module according to claim 3, wherein a side surface of the block portion facing the mirror drive mechanism is closer to the mirror drive mechanism than a position where the second combined light and the fourth light are combined in the splitter.

Images