JP2023028729A - Distance measuring device - Google Patents

Abstract

To provide a distance measuring device with which it is possible to efficiently dissipate the heat of a light source board.SOLUTION: A distance measuring device 101 comprises: a light emission unit 10 for emitting light, which includes a light source element 13 that emits light; a scan unit 20 for scanning the light emitted from the light emission unit; a light reception unit 30 for receiving reflected light from an object; a housing 50 for accommodating the light emission unit, the scan unit and the light reception unit in the inside and having a window 51 that passes light through; and a holding member 60 for holding the light emission unit by being contacted with the light emission unit, which is fixed to the housing by being contacted with the housing and dissipates the heat of the light emission unit to the outside of the housing.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to ranging devices.

For example, an optical measuring device for vehicles as described in Patent Document 1 is known. An optical measurement device emits pulsed light such as laser light from a light emitting part, detects reflected light from an object with a light receiving part, and measures the time of flight (TOF: Time Of Flight) from irradiation to light reception. By doing so, the presence or absence of the object can be detected and the distance to the object can be measured.

2. Description of the Related Art As an optical measuring device for detecting the existence or non-existence of an object and measuring the distance to the object, for example, an optical measuring device for vehicles as described in Patent Document 1 is known. 2. Description of the Related Art In an optical measurement device, a light source element that emits laser light is fixed to a housing and used. For example, a light emitting section including a light source element is used by being fixed to a housing by a supporting member called an optical frame together with a light scanning section and a light receiving section.

Japanese Patent Application Publication No. 2014-522984

In general, various members (hereinafter simply referred to as “plurality of members”) such as a projection lens holder and holder driving mechanism are provided between the optical frame and the light emitting section. That is, the light emitting section is connected to the optical frame through the plurality of members. The heat generated in the light emitting section is radiated to the housing through these members and the optical frame.

However, since multiple members are interposed between the light emitting unit and the housing, the contact thermal resistance between the members is large, and the micron-scale gaps between the members act as heat insulating layers, so the light emitting unit cannot Since the heat conductivity to the housing is lowered, it is difficult to sufficiently dissipate the heat generated from the light emitting section. If the heat of the light-emitting portion cannot be dissipated sufficiently, the temperature of the light source element rises, resulting in a decrease in the light output of the light source element or deterioration of the light source element. Therefore, there is a demand for a technique capable of efficiently dissipating the heat of the light-emitting portion and exhibiting high heat dissipation performance.

The present disclosure can be implemented as the following forms.

According to one aspect of the present disclosure, a ranging device is provided. This distance measuring device is a distance measuring device using light, and includes a light source element (13) for emitting light, a light emitting section (10) for emitting light, and scanning light emitted from the light emitting section (10). a scanning unit (20) for scanning, a light receiving unit (30) for receiving reflected light from an object, and a window (51) for accommodating the light emitting unit, the scanning unit, and the light receiving unit inside and transmitting the light. and a member that holds the light-emitting unit in contact with the light-emitting unit, the member is fixed to the housing while in contact with the housing, and dissipates the heat of the light-emitting unit to the housing. and a holding member (60, 70, 80).

According to this configuration, the holding member is a member that holds the light-emitting unit in contact with the light-emitting unit, and is fixed to the housing while making contact with the housing. Therefore, the heat generated in the light emitting section is dissipated to the housing via the holding member, which is a single member fixed inside the housing. The holding member is fixed inside the housing, and the heat dissipation path from the light emitting unit to the housing does not involve a plurality of members. For this reason, compared to the case where a plurality of members are interposed between the light emitting unit and the housing, there is no contact thermal resistance or gap between the members, and the heat generated from the light emitting unit can be efficiently dissipated into the housing. And heat can be dissipated to the outside of the housing.

1 is a side sectional view schematically showing a distance measuring device according to a first embodiment of the present disclosure; FIG. 1 is a plan view schematically showing a distance measuring device according to a first embodiment; FIG. Fig. 10 is a side cross-sectional view schematically showing a distance measuring device according to a second embodiment of the present disclosure; FIG. 11 is a side cross-sectional view schematically showing a distance measuring device according to a third embodiment of the present disclosure; FIG. 11 is a side cross-sectional view schematically showing a distance measuring device according to a fourth embodiment of the present disclosure; FIG. 11 is a side cross-sectional view schematically showing a distance measuring device according to another embodiment; FIG. 11 is a side cross-sectional view schematically showing a distance measuring device according to another embodiment;

A plurality of embodiments of the present disclosure will be described below with reference to the drawings.
A. First embodiment:
A1. Range finder configuration:
The configuration of the first embodiment will be described with reference to FIGS. 1 and 2. FIG. The distance measuring device 101 of the first embodiment measures the distance to an object by irradiating light and detecting reflected light from the object irradiated with light. A range finder is, for example, an in-vehicle LiDAR mounted on a vehicle such as an automobile, and is used to detect various objects present in the surroundings such as in front of the vehicle.

As shown in FIGS. 1 and 2, the distance measuring device 101 includes a light emitting section 10, a scanning section 20, a light receiving section 30 (see FIG. 2), a control section 40, a housing 50, and a holding member 60. In FIG. 1, the upper side of the drawing is the scanning direction. In this embodiment, it is assumed that the vertical direction shown in FIG. is referred to as "right" and the left is referred to as "left". In the following description, the upper side in FIG. 2 is defined as "front" and the lower side is defined as "rear". However, there are various installation modes of the distance measuring device 101 in practice, and the installation state is not limited to that shown in FIG.

The light emitting unit 10 is a component that emits a pulsed laser beam L (hereinafter simply referred to as “laser beam L”), and includes a light source substrate 11 and a projection lens 12 . The light source substrate 11 has a light source element 13 (see FIG. 2) that emits laser light L, and a drive circuit 14 (see FIG. 2) that is electrically connected to the light source element 13 and drives the light source element 13 . A semiconductor laser element is, for example, a laser diode. The light source substrate 11 is fixed to the upper surface 68 of the holding member 60 . Details of the holding member 60 will be described later. The distance from the light source element 13 and the angle of rotation of the projection lens 12 can be adjusted by driving the lens position adjustment unit 16 .

The scanning unit 20 has a deflection mirror 21 and a swing shaft 22 . The deflecting mirror 21 is a plate-like member having a reflecting surface that reflects light. The deflection mirror 21 is fixed to a swing shaft 22 extending in the horizontal front-rear direction, and can be rotated vertically together with the swing shaft 22 by driving a mirror rotation drive section 23 . The mirror rotation drive unit 23 is, for example, a rotary solenoid, and receives a control signal from the control unit 40 to repeat forward and reverse rotation within a predetermined angular range.

The scanning unit 20 reflects the laser light L output from the light emitting unit 10 by the deflecting mirror 21 and emits the laser light L in a direction corresponding to the rotational position of the deflecting mirror 21, thereby scanning within a preset scanning range. Scanning of the laser light L to .

The light receiving unit 30 receives the reflected light from the object irradiated with the laser light L and converts it into an electric signal. As shown in FIG. 2 , the light receiving section 30 has a light receiving lens 31 and a light receiving array 32 . Although not shown in FIGS. 1 and 2, the distance measuring device 101 has a position adjusting mechanism for adjusting the position of the light receiving lens 31. As shown in FIG.

The control unit 40 controls the positions of the lenses 12 and 31, the rotation of the deflection mirror 21, control signals sent to the drive circuit 14, and the like. Further, the control unit 40 calculates the distance to the object that reflected the laser light L. FIG. Specifically, the control unit 40 identifies the timing at which the reflected light is received based on the waveform of the electrical signal output from the light receiving unit 30, and determines the distance from the object based on the difference from the timing at which the laser beam L is output. Ask for In addition to the distance, the control unit 40 can obtain information related to the object such as the orientation of the object.

The housing 50 is a box made of resin or an aluminum alloy having a rectangular parallelepiped outer shape and one surface (the upper surface in FIG. 1) being open. A transparent optical window 51 that transmits light is provided in the opening of the housing 50 so as to cover the entire opening. Inside the housing 50, the light emitting section 10, the scanning section 20, the light receiving section 30, and the control section 40 are accommodated. Hereinafter, various optical system members constituting the light emitting unit 10, the scanning unit 20, and the light receiving unit 30 will be collectively referred to simply as "various optical system members".

The control unit 40 is provided at a lower position in the housing 50 than various optical system members. Also, the light emitting unit 10 , the scanning unit 20 , and the light receiving unit 30 are provided at upper positions within the housing 50 . In the upper space within the housing 50, the path from projection to reception of the laser light L is not blocked by other members.

The holding member 60 is a holding member that contacts the light source substrate 11 and holds various optical system members including the light source substrate 11 at prescribed positions inside the housing 50 . The holding member 60 is fixed to the housing 50 in contact with the bottom portion 52 of the housing 50 , and radiates the heat of the light source substrate 11 to the housing 50 and the outside of the housing 50 . That is, it functions as a positioning member for regulating the positions of various optical system members and also as a heat dissipation member for the light emitting section 10 . The holding member 60 is a solid rectangular parallelepiped member, that is, a columnar member, and is made of an aluminum alloy. The material of the holding member 60 is not limited to the aluminum alloy, and may be metal such as copper as long as the heat dissipation performance is ensured.

The holding member 60 has a fastening member such as a screw (not shown) attached to the other portion of the housing 50 facing the optical window 51 (lower portion in FIG. 1, hereinafter referred to as "bottom portion 52"). is fixed by The holding member 60 has a body portion 61 and an outward projecting portion 62 . The main body portion 61 and the outward projecting portion 62 are coaxially and integrally formed. The body portion 61 occupies most of about 80% or more of the entire holding member 60 other than the outward protrusion 62 and is housed inside the housing 50 .

The outward projecting portion 62 is a part of the housing 50 protruding to the outside of the housing 50 . The outer projecting portion 62 has a rectangular parallelepiped shape with a larger horizontal cross-sectional shape than the body portion 61 . Outer projection 62 has a heat sink structure 64 with a plurality of fins 63 . In the present embodiment, the entire outward projecting portion 62 is configured as the heat sink structure portion 64 , but only a portion of the outward projecting portion 62 may be configured as the heat sink structure portion 64 . The heat sink structure 64 has a base 66 in contact with the bottom 52 of the housing 50, a plurality of fins 63 erected from the base 66, and a plate-like lid 67 connecting the projecting ends of the fins 63. ing. The shape of the fins 63 can adopt a well-known shape such as a plate shape or a columnar shape.

An O-ring 71 is provided between the upper surface of the outer projecting portion 62 and the bottom portion 52 of the housing 50 at the boundary between the outer projecting portion 62 and the main body portion 61 to seal the gap therebetween. The O-ring 71 corresponds to a "sealing member". The O-ring 71 ensures airtightness and dustproofness inside the housing 50 .

Various optical system members are held in the body portion 61 . Specifically, the projection lens 12 is held on the left side surface 65 of the holding member 60 together with the lens position adjusting section 16 via the projection lens holder 15 . The deflection mirror 21 and the swing shaft 22 are held on the left side surface 65 of the holding member 60 together with the mirror rotation driving section 23 via the mirror holder 24 . The light-receiving lens 31 is held on the front side surface 69 (see FIG. 2) of the holding member 60 via the light-receiving lens holder 33 . The light receiving array 32 is held on the front side surface 69 of the holding member 60 via the light receiving substrate holder 34 .

In addition, one end surface (upper surface 68 in FIG. 1) of the main body portion 61 opposite to the outward projecting portion 62 and the surface to which the light source substrate 11 is fixed is located inside the housing 50 in the height direction of the housing 50. It is located above the substantially central position (vertical direction in FIG. 1).

Further, the distance measuring device 101 has a vehicle fastening portion 72 . The vehicle fastening portion 72 is a member having a rectangular parallelepiped shape, which is provided on each of the right side portion 53 and the left side portion 54 of the housing 50 . The vehicle fastening portion 72 is provided at a position away from the outward projecting portion 62 of the holding member 60 . The vehicle fastening portion 72 is fastened to a connection bracket provided on the vehicle with a screw or the like (not shown), thereby fixing the distance measuring device 101 to a predetermined portion of the vehicle. The vehicle fastening portion 72 corresponds to a "fixing portion".

[effect]
(1) According to the distance measuring device 101 of the first embodiment, heat generated in the light source substrate 11 is transferred through the holding member 60 fixed inside the housing 50 as indicated by the arrow A in FIG. heat is radiated to the housing 50 and to the outside of the housing 50. Since the holding member 60 is one solid columnar member and is fixed inside the housing 50 , the heat dissipation path from the light source substrate 11 to the housing 50 does not pass through a plurality of members. Specifically, the plurality of members are, for example, the mirror holder 24, the lens holder 15, the lens position adjusting section 16, the mirror rotation driving section 23, and the like. In the first embodiment, these members are fixed to the outer walls (side surfaces 65 and 69) of the holding member 60. As shown in FIG.

If a plurality of members are interposed between the heat dissipation path from the light source substrate 11 to the housing 50, the contact thermal resistance between the members is large, and the gaps of microns between the members act as heat insulating layers. , the thermal conductivity from the light source substrate 11 to the housing 50 decreases. However, according to the first embodiment, since a plurality of members are not interposed between the heat dissipation paths from the light source substrate 11 to the housing 50, contact thermal resistance and gaps between members do not occur, and the light source substrate 11 The heat generated from the housing can be efficiently radiated to the housing 50 and the outside of the housing 50 . That is, the heat generated from the light source substrate 11 can be sufficiently dissipated, and the temperature rise of the light source element 13, the decrease of the light output, and the deterioration of the light source element 13 can be suppressed.

In addition, since the holding member 60 is a single member and there is no tolerance between members, various optical system members can be accurately positioned via the holding member 60, and optical adjustments (focal length, optical axis, etc.) can be achieved. adjustment, etc.) can be easily performed.

(2) If the light source substrate 11 can be directly attached to the housing 50, the heat radiation efficiency will be improved. However, since the distance measuring device 101 has optical restrictions such as ensuring an optical path and adjusting the positions of the lenses 12 and 31 and the deflection mirror 21, it is necessary to provide the light source substrate 11 near the deflection mirror 21. Therefore, it is difficult to directly attach the light source substrate 11 to the housing 50 . If the light source substrate were to be directly attached to the housing with emphasis on heat dissipation, it would be necessary to interpose a plurality of mirrors, which would be undesirable from the viewpoint of reducing the size and weight of the entire device. In the above-described embodiment, although the light source substrate 11 is not directly attached to the housing 50, by fixing it to the housing 50 with a single holding member 60, in addition to a high heat dissipation effect, the size of the entire device can be reduced. can do.

(3) The holding member 60 has an outward projecting portion 62 projecting outward from the housing 50 . That is, since a part of the holding member 60 is directly exposed to the outside (outside air) of the housing 50, the heat dissipation effect can be further improved.

(4) In addition, since the outward projecting portion 62 of the holding member 60 has the heat sink structure portion 64, the heat dissipation can be further improved.

(5) Since the holding member 60 is made of aluminum alloy which is light and has high heat dissipation, the heat dissipation can be improved and the weight of the entire device can be reduced.

(6) The light emitting section 10 , the scanning section 20 and the light receiving section 30 are all held by the holding member 60 . Therefore, not only the heat generated in the light source substrate 11 but also the heat generated in the deflection mirror 21 and the light receiving array 32 can be efficiently dissipated to the housing 50 and the outside of the housing 50 via the holding member 60. can.

B. Second embodiment:
Next, a distance measuring device 102 according to a second embodiment of the present disclosure will be described with reference to FIG. In addition, in each embodiment described below including the second embodiment, the same reference numerals are given to substantially the same configurations as in the first embodiment, and the description thereof is omitted.

The range finder 102 of the second embodiment differs from the range finder 101 of the first embodiment in the configuration of the heat sink structure 64 . The heat sink structure portion 64 of the holding member 70 of the second embodiment is composed only of the base portion 66 and the fins 63 and does not have the lid portion 67 . For example, as described in the first embodiment, when the distance measuring device 101 is set horizontally with respect to the ground and the cover portion 67 is not formed, the warm air will flow upward in the space between the fins 63 . There is a risk that the liquid will go to the outside and stay in a portion near the housing 50 . However, depending on the installation posture of the distance measuring device with respect to the ground, warm air can be dispersed and the heat dissipation effect of the heat sink structure 64 can be enhanced by not forming the cover 67 as in the second embodiment. sometimes it is possible.

According to the second embodiment, the same effects as those of the first embodiment can be obtained.

C. Third embodiment:
Next, a distance measuring device 103 according to a third embodiment of the present disclosure will be described with reference to FIG. The distance measuring device 103 of the third embodiment differs from the distance measuring device 101 of the first embodiment in the position of the vehicle fastening portion. As shown in FIG. 4 , in the distance measuring device 103 of the third embodiment, the vehicle fastening portion 73 is provided below the housing 50 and integrally with the outer wall of the outward projecting portion 62 . The vehicle fastening portion 73 has a rectangular parallelepiped shape, similarly to the vehicle fastening portion 72 of the first embodiment, and is provided on each of the left and right side surfaces of the outward projecting portion 62 . The position, number, shape, etc. of the vehicle fastening portion 73 can be changed as appropriate.

According to the third embodiment, the same effects as those of the first embodiment can be obtained. Furthermore, as described in detail above, the holding member 60 holds the respective holders 15, 24, 33, 34, the lens position adjusting section 16, the mirror rotation driving section 23, etc., and is heavy. By providing the vehicle fastening portion 73 to the holding member 60 having a large weight in this manner, the vehicle can directly hold the heavy member, and various optical systems connected to the holding member 60 against vibration and other holding members 60 can be mounted. The durability of the member can be improved.

D. Fourth embodiment:
Next, a distance measuring device 104 according to a fourth embodiment of the present disclosure will be described with reference to FIG. A range finder 104 of the fourth embodiment differs from the range finder 101 of the first embodiment in that it does not have an outward projecting portion 62 . As shown in FIG. 5, the holding member 80 of the fourth embodiment is composed of only the body portion 61. As shown in FIG.

According to the fourth embodiment, the same effects (1), (2), (5), and (6) as those of the first embodiment can be obtained.

E. Other embodiments:
(E1) In each of the above embodiments, the holding members 60, 70, and 80 are fixed to the bottom portion 52 of the housing 50. However, like the distance measuring device 105 shown in FIG. It may be fixed to the portions 53 and 54 . As shown in FIG. 6 , the holding member 90 has a body portion 61 and a plate-like portion 91 continuous with the body portion 61 . The plate-like portion 91 is a plate-like member having a rectangular shape in plan view. Left and right side edges of the plate-like portion 91 are fixed to the left and right side portions 53 and 54 of the housing 50 . Even with such a form, the heat generated in the light source substrate 11 can be directly radiated to the housing 50, so that a high heat radiation effect can be achieved.

That is, the holding member only needs to be a single member that holds the light source substrate 11 and does not interpose another member between the heat radiation path from the light source substrate 11 to the housing 50 . Therefore, the shape of the holding member may be other shapes such as a columnar shape in addition to the square columnar shape.

(E2) Further, as another example of the distance measuring device 105 shown in FIG. can be fixed to Optical system components such as the projection lens 12 and the deflecting mirror 21 are held by the same members as the light source substrate 11 (holding members 60, 70, and 80 in each of the above embodiments) because of the importance of relative position adjustment with the light source substrate 11. It is preferable that Therefore, the portion constituting the holding member 60 may be fixed anywhere.

Moreover, from the viewpoint of the optical adjustment accuracy and the parts and assembly tolerances, the light receiving section 30 (the light receiving lens 31 and the light receiving array 32 ) is preferably fixed to the holding member 60 together with the light emitting section 10 . However, if optical adjustment with the light emitting unit 10 is possible, it may be fixed to another part in the housing 50 instead of being provided integrally with the holding member 60 .

(E3) In each of the above embodiments, the vehicular fastening portions 72 and 73 are rectangular parallelepipeds, and two are provided on the sides of the housing 50 or the outward projecting portion 62. The shape and the number of brackets can be changed as appropriate according to the shape of the provided bracket or the like.

(E4) In the light emitting unit 10 of each of the above embodiments, the light source element 13 and the driving circuit 14 are mounted on the light source substrate 11. Alternatively, it may be composed of a single unit.

The present disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from the scope of the present disclosure. For example, the technical features in each embodiment corresponding to the technical features in the form described in the outline of the invention are used to solve some or all of the above problems, or Substitutions and combinations may be made as appropriate to achieve part or all. Also, if the technical features are not described as essential in this specification, they can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 10... Light emission part 11... Light source substrate 12... Drive circuit 13... Light source element 20... Scanning part 30... Light receiving part 40... Control part 50... Housing 51... Optical window 60,70,80 ... holding member, 101 ... distance measuring device

Claims (9)

A distance measuring device using light,
a light emitting part (10) for emitting light, including a light source element (13) for emitting light;
a scanning unit (20) for scanning the light emitted from the light emitting unit;
a light receiving part (30) for receiving reflected light from an object;
a housing (50) housing the light-emitting unit, the scanning unit, and the light-receiving unit therein and having a window (51) for transmitting light;
A holding member (60, 70, 80) that is in contact with the light emitting unit and holds the light emitting unit, is fixed to the housing in contact with the housing, and dissipates the heat of the light emitting unit to the housing. )and,
A rangefinder with a 2. The distance measuring device according to claim 1, wherein said holding member comprises a solid columnar member. 3. The measuring device according to claim 1, wherein the holding member has a main body portion (61) housed inside the housing and an external projecting portion (62) projecting to the outside of the housing. distance device. 4. The distance measuring device according to claim 3, further comprising a seal member (65) for sealing between the outer projecting portion and the housing. 5. A range finder according to claim 3 or 4, wherein the outward protrusion comprises a heat sink structure (64) having a plurality of fins (63). 6. The apparatus according to any one of Claims 3 to 5, further comprising a fixing portion (73) provided on the outer projecting portion for fixing the range finder to a target on which the range finder is mounted. rangefinder. The distance measuring device according to any one of claims 1 to 6, wherein the holding member is made of an aluminum alloy. The distance measuring device according to any one of claims 1 to 7, wherein the holding member holds the scanning section and the light receiving section in addition to the light emitting section. The light emitting unit according to any one of claims 1 to 8, wherein the light emitting unit includes a light source substrate (11) having a drive circuit (14) electrically connected to the light source element to drive the light source element. rangefinder.

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