JP3328405B2 - Transmitter and receiver of optical radar device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light transmitting / receiving section of an optical radar apparatus used as an on-vehicle radar apparatus, and more particularly, to a light reflecting section for confirming a light transmitting direction. The present invention relates to a light transmitting and receiving unit of an optical radar device provided with the light transmitting and receiving unit.

[0002]

2. Description of the Related Art An optical radar device has been developed as a vehicle-mounted radar device. This optical radar device emits a pulsed light beam in front of a vehicle, and a light transmitting and receiving unit that receives a light beam reflected by an object such as a preceding vehicle and returned by a photoelectric conversion element, and emits a light beam. And a distance detecting unit that detects a distance to an object that has generated the reflected light based on a time required until the reflected light is received.

The direction of a light beam emitted from the light transmitting unit of the light transmitting and receiving unit varies due to a deviation between the center of the light beam of the light emitting element and the optical axis of the light transmitting lens. For this reason, when attaching the light transmitting / receiving part of such an optical radar device to a vehicle, it is necessary to check the light transmitting direction and make the mounting angle coincide with the traveling direction of the vehicle. However, when invisible light such as infrared light is used as the light transmission beam, there is a disadvantage that the light transmission direction cannot be visually confirmed. A device for resolving this inconvenience is disclosed in Japanese Utility Model Application No. 5-9525, which is a prior application filed by the present applicant.

According to the invention, a light reflecting section including a reflecting mirror and an angle adjusting mechanism of the reflecting mirror is mounted between a light transmitting section and a light receiving section, and the angle adjusting mechanism is operated at an assembling stage. The optical axis of the reflecting mirror is made to coincide with the light transmission direction of the light transmission beam. When attaching this transmitter / receiver to the vehicle,
By irradiating the light reflector with visible light generated using a handy light source such as a flashlight and observing the reflected light from the reflector, the direction of the transmitted light beam can be confirmed and transmitted to the vehicle. The mounting angle is adjusted.

[0005]

According to the optical radar device of the prior application, a reflecting mirror for confirming a light transmitting direction is provided between a light transmitting unit and a light receiving unit. However, the inventor has subsequently discovered that such mutual arrangement is not optimal and that there is room for improvement. Therefore, another object of the present invention is to provide an optical radar device in which the arrangement of the light reflection unit, the light transmission unit, and the light reception unit is optimized.

Further, according to the transmission / reception section of the optical radar apparatus of the prior application, an angle adjusting mechanism for adjusting the optical axis of the reflecting mirror is realized by four screws. However, the inventor has subsequently discovered that such an angle adjustment mechanism is not optimal in terms of ease of operation and the like, and there is room for improvement. Accordingly, it is an object of the present invention to provide an optical radar device in which an optical axis adjustment operation is facilitated by improving an angle adjustment mechanism of a reflecting mirror.

[0007]

According to the optical transmitter / receiver of the optical radar apparatus of the present invention, the light transmitter and the light receiver are arranged adjacent to each other, and the light reflector is adjacent to the light receiver or the light transmitter. It is arranged. According to a preferred embodiment, the light transmitting section, the light receiving section and the light reflecting section are arranged such that their centers are located substantially on a straight line, and the light reflecting section is adjacent to one of the light receiving section or the light transmitting section. Are located. According to another aspect of the present invention, the angle adjusting mechanism of the light reflecting portion includes a fixed body disposed behind the light reflecting body, and an elastic body interposed between the fixed body and the light reflecting body. Restraining means for restraining the three portions around the light reflector to the fixed body while compressing the elastic body and allowing a change in the distance from the fixed body.

[0008]

According to the present invention, instead of disposing a light reflecting portion between a light transmitting portion and a light receiving portion as shown in FIG.
As shown in (A), a light transmitting unit and a light receiving unit are arranged adjacent to each other, and a light reflecting unit is arranged outside thereof, for example, adjacent to the light receiving unit as illustrated. In FIG. 6, the directivity of the light transmitting unit (spatial distribution of the light transmitting beam) is indicated by a solid line, and the directivity of the light receiving unit (spatial distribution of light receiving sensitivity) is indicated by a broken line. The detectable range as the optical radar device is a range indicated by oblique lines where regions indicated by the respective directivities intersect.
This detectable range increases as the distance between the light transmitting unit and the light receiving unit decreases. Therefore, according to the present invention, the distance between the light transmitting unit and the light receiving unit can be reduced as compared with the case of the prior art, and the effect that the detection range as the optical radar device can be expanded accordingly.

According to the angle adjusting mechanism of the present invention, the three portions on the periphery of the light reflector allow the elastic body interposed between the light reflector and the fixed body to be compressed and change the distance from the fixed body. While being restrained by this fixed body. By realizing such a restraining means with a screw or the like which can be operated from the front, labor and time required for angle adjustment are greatly reduced.

[0010]

FIG. 1 is a sectional view showing the structure of a light transmitting / receiving section of an optical radar apparatus according to one embodiment of the present invention. FIG. 2 is an enlarged partial sectional view showing the reflecting mirror of FIG. FIG. 3 is an enlarged partial perspective view showing the reflecting mirror and its peripheral portion in an enlarged manner.
FIG. 2 is a perspective view of a light transmitting and receiving unit in FIG. 1. First, referring to the cross-sectional view of FIG. 1, in this light transmitting and receiving unit, a light transmitting unit 10 and a light receiving unit 20 are arranged adjacent to each other, and further adjacent to the light receiving unit 20 and opposite to the light transmitting unit 10. The light reflection part 30 is arrange | positioned at the side. The light transmitting unit 10, the light receiving unit 20, and the reflecting unit 30 are arranged such that their centers are located substantially on a straight line. The light transmitting unit 10 includes a light emitting element 11 such as a laser diode and a light transmitting lens disposed in front of the light emitting element 11, and the light receiving unit 20 includes a light receiving element 21 such as an avalanche photo diode and a light receiving lens disposed in front thereof. It is composed of

The light transmitting lens 12 of the light transmitting unit 10 and the light receiving unit 2
The zero light receiving lens 22 is held on a frame 42 whose peripheral portion is held by a housing 44. A plurality of holding rods 43a, 4
The printed wiring board 41 held by the frame 42 via 3b is disposed substantially parallel to the frame 42 and opposed to the frame 42. The light emitting element 11 and the light receiving element 21 are arranged on the printed wiring board 41. Light transmitting unit 1
At 0, the transmission of the light beam radiated in front of the light transmitting lens 12 due to a positional shift between the center of the light beam radiated from the light emitting element 11 and the optical axis of the light transmitting lens 12 or the like. Variations occur in the direction. In order to adjust the light receiving direction of the light receiving unit 20 according to the varied light transmitting direction, the relative position between the light receiving element 21 and the light receiving lens 22 is adjusted. The adjustment of the relative position is performed by adjusting the position of the holding member 23 holding the light receiving lens 22 in the vertical direction in FIG.

The light reflecting unit 30 includes a reflecting mirror 31 for confirming the light transmitting direction of the light transmitting unit 10 and an angle adjusting unit for matching the optical axis of the reflecting mirror 31 with the light transmitting direction of the light transmitting unit 10. Mechanism. The angle adjusting mechanism includes a flat plate 32 for holding the reflecting mirror 31 at a central portion, mounting holes 33 formed on three sides of a peripheral portion of the flat plate 32, and a frame 42 at a position substantially corresponding to the mounting holes. A screw hole 34 formed in
An O-ring 35 disposed between the flat plate 32 and the frame 42 surrounding these screw holes 34, and flathead screws 36a, 36b,
36c. Three countersunk screws 36a, 36b, and 36c are screwed into the screw holes 34 formed on the frame 42 through the mounting holes 33 formed on the flat plate 32 and the central portion of the O-ring 35, respectively. .

As shown in an enlarged partial perspective view of FIG. 3, an orthogonal coordinate system (X,
(Y, Z), countersunk screws 36a and 36c are arranged along the X axis, and countersunk screws 36a and 36b are arranged along the Y axis. The screw was fixed on the flat plate 32 by adjusting the screwing depth of the countersunk screw 36c into the corresponding screw hole 34 while the screwing depth of the countersunk screw 36a into the corresponding screw hole 34 was fixed. The angle of the reflecting mirror 31 around the Y axis (in the horizontal direction in the figure) is adjusted. Further, with the countersunk screw 36a fixed in the screwing depth to the corresponding screw hole 34, the countersunk screw 3
By adjusting the screwing depth of the 6b into the corresponding screw hole 34, the angle (in the vertical direction in the figure) around the Y axis of the reflecting mirror 31 fixed on the flat plate 32 is adjusted. . In this way, by adjusting the screwing depth of the countersunk screws 36b and 36c while the screwing depth of the countersunk screw 36a is fixed, the flat plate 32 around the X axis and the Y axis orthogonal to the optical axis is adjusted. The rotation angle can be adjusted independently.

As shown in the enlarged partial sectional view of FIG. 2, the mounting holes 3 corresponding to the inclined surfaces on the lower surface of the heads of the flat head screws 36a and 36b.
The inner peripheral surface 3 is not in a state of surface contact unlike the prior art, but is in a state close to point contact as illustrated in the case of the countersunk screw 36a or in a line as illustrated in the case of the countersunk screw 36b. Contact in a state close to contact. That is, the support mechanism of the flat plate 32 using the three flathead screws is a simple support that restricts the displacement in the X-axis direction and the Y-axis direction while allowing the flat plate 32 to be freely rotated around the X-axis and the Y-axis. It will be close. As a result, two axes (X axis and Y axis) orthogonal to the optical axis direction (Z axis direction)
The rotation of the flat plate 32 about the axis) is very smooth.
Furthermore, since an O-ring that can be deformed not only in the optical axis direction but also in the horizontal direction is used as the elastic body, the adhesion between the frame body 42, the flat plate 32 and the elastic body is improved, and so-called play is greatly reduced. You. As a result, extremely high-precision angle adjustment can be performed.

The annular projections 37 formed on the respective peripheral portions of the O-rings 35 serve to hold the corresponding O-rings 35 therein and to limit the distance between the flat plate 32 and the frame 42. And a function of avoiding the disadvantage that the O-ring 35 is excessively crushed.

The detection of the light transmitting direction, the adjustment of the light receiving direction, and the adjustment of the optical axis of the reflecting mirror 31 are performed as follows. First, with the glass plate 45 removed from the housing 44, the light transmitting and receiving unit of FIG. 1 is fixed to an appropriate place such as a table, and the light emitting element 11 emits light. By detecting the arrival position of the light beam emitted from the light emitting element 11 from the position of the detecting light receiving element in front of the light transmitting and receiving unit, the light transmitting direction of the light transmitting unit 10 is detected. Next, the light emitting element for detection arranged at a predetermined position in front of the light transmitting / receiving section is caused to emit light, and the light beam emitted from the light emitting element for detection is received by the light receiving element 21 while adjusting the position of the light receiving lens 22. By doing so, the light receiving direction of the light receiving unit 20 is adjusted.

Finally, the light-emitting element for detection arranged at a predetermined position in front of the light transmitting / receiving section emits light, and irradiates the reflecting mirror 31. The reflected light from the reflecting mirror 31 is transmitted to a predetermined light in front of the light transmitting / receiving section. By operating the angle adjusting mechanism so that the light receiving element for detection arranged at the position can receive light, the optical axis of the reflecting mirror 31 is made substantially coincident with the light transmitting direction of the light transmitting unit 10. This angle adjustment can be realized by rotating the heads of the countersunk screws 36b and 36c from the front with a screwdriver, so that the operation is much easier as compared with the angle adjustment mechanism of the prior art which requires operation from the rear. .

As described above, the configuration in which the light reflecting portion 30 is disposed adjacent to the light receiving portion 20 has been exemplified. However, a configuration in which the light reflecting unit 30 is arranged adjacent to the light transmitting unit 10 may be adopted.

Further, an example has been described in which the light transmitting unit 10, the light receiving unit 20, and the light reflecting unit 30 are arranged such that their centers are located on a straight line. However, as shown in the perspective view of FIG. 5 by the light transmitting lens 12, the light receiving lens 22, and the reflecting mirror 31, the light transmitting unit 10 and the light receiving unit 30 are arranged adjacent to each other, The light reflecting portions may be arranged above each of them.

Further, an example has been described in which the optical axis of the reflecting mirror 31 is adjusted so as to substantially coincide with the light transmitting direction of the light transmitting unit 10.
However, it is also possible to adjust the optical axis of the reflecting mirror 31 so as to substantially coincide with the light receiving direction of the light receiving unit 20.

Further, the configuration in which the reflecting mirror 31 is attached to the flat plate 32 has been exemplified. However, the reflecting mirror 31 may be omitted by mirror-finishing the surface of the flat plate 32 or the like.

Also, an example has been described in which an angle adjusting mechanism is formed by using a screw groove formed in the frame plate 42 and a countersunk screw screwed into the screw groove. However, the tip portion is formed by the opening 3 of the flat plate 32.
An angle adjusting mechanism can also be realized by a bolt that is planted on the frame body 42 side while projecting forward from 3 and a nut that is screwed to this tip.

[0023]

As described above in detail, the transmitting / receiving section of the radar apparatus according to the present invention is different from the transmitting / receiving section in that the light reflecting section is provided between the transmitting section and the receiving section. Are arranged adjacent to each other, and the light reflecting portion is arranged outside thereof, so that the distance between the light transmitting portion and the light receiving portion can be reduced, and the detectable range of an object as a radar device can be expanded.

Further, according to the angle adjusting mechanism of the light reflecting portion according to the present invention, three portions around the light reflecting member compress the elastic member interposed between the light reflecting member and the fixed member while compressing the elastic member. The structure is constrained by this fixed body while allowing the change of the interval of the angle. By implementing such a constraining means with screws that can be operated from the front, the labor and time required for angle adjustment are greatly reduced. Is done.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a light transmitting and receiving unit of an optical radar device according to an embodiment of the present invention.

FIG. 2 is an enlarged partial cross-sectional view showing the light reflecting portion 30 of FIG. 1 and a peripheral portion thereof in an enlarged manner.

FIG. 3 is an enlarged partial perspective view showing the light reflecting portion 30 of FIG. 1 and a peripheral portion thereof in an enlarged manner.

FIG. 4 is a perspective view of a light transmitting and receiving unit of FIG. 1;

FIG. 5 is a perspective view illustrating a configuration of a light transmitting and receiving unit of an optical radar device according to another embodiment of the present invention.

FIG. 6 is a conceptual diagram for explaining the operation of the present invention.

[Explanation of symbols]

 10 Transmitter section 20 Receiver section 30 Reflector section 31 Reflector (Reflector) 32 Flat plate (Movable body) 33 Opening 34 Screw hole 35 O-ring (Elastic body) 36a, 36b Countersunk screw (Screw) 42 Frame (Fixed body) )

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Takeda 2-1910 Nisshincho, Omiya City, Saitama Prefecture Kansei Co., Ltd. (56) References Japanese Utility Model 6-69867 (JP, U) Japanese Utility Model 2 59474 (JP, U) Japanese Utility Model Showa 59-89273 (JP, U) Utility model registration 2587613 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01S ^7/ 48-7/51 G01S 17/00-17/95

Claims (7)

(57) [Claims] A light transmitting unit for transmitting a light beam; a light receiving unit for receiving a light beam transmitted from the light transmitting unit and reflected by an object; a light reflector and an optical axis of the light reflector; A light reflecting unit including an angle adjusting mechanism that is adjusted to substantially match a light transmitting direction of the light transmitting unit or a light receiving direction of the light receiving unit, the light transmitting and receiving unit of the optical radar device, And the light receiving section are disposed adjacent to each other, and the light reflecting section is disposed adjacent to one or both of the light receiving section and the light transmitting section. 2. The light-transmitting unit, the light-receiving unit, and the light reflector according to claim 1, wherein the light-transmitting unit, the light-receiving unit, and the light reflector are arranged such that their centers are substantially on a straight line. A light transmitting and receiving unit of the optical radar device, which is arranged adjacent to one side. 3. The light reflector according to claim 1, wherein the angle adjusting mechanism for the light reflector is interposed between a fixed body disposed behind the light reflector and the fixed body and the light reflector. Elastic body, and constraining means for constraining three places around the light reflector to the fixed body while compressing the elastic body and allowing a change in the interval between the elastic body and the fixed body. A light transmitting / receiving unit of an optical radar device, characterized by the above. 4. The fixing device according to claim 3, wherein the restraining means includes three mounting holes formed at three locations around the light reflector, and three fixing holes substantially corresponding to the mounting holes. An optical radar comprising: a screw hole formed in a body; and a screw that is screwed into each of the screw holes formed in the fixed body through each of the mounting holes formed in the light reflector. Transmitting and receiving unit of the device. 5. The light transmitting and receiving unit of the optical radar device according to claim 4, wherein the screw is a flat head screw. 6. The light transmitting and receiving unit of an optical radar device according to claim 3, wherein the elastic body is an O-ring. 7. A light transmitting section for transmitting a light beam, a light receiving section for receiving a light beam transmitted from the light transmitting section and reflected by an object, a light reflector and an optical axis of the light reflector. A light reflecting unit including an angle adjusting mechanism that is adjusted to substantially match the light transmitting direction of the light transmitting unit or the light receiving direction of the light receiving unit. The angle adjustment mechanism includes: a fixed body disposed behind the light reflector, an elastic body interposed between the fixed body and the light reflector, and three portions around the light reflector, A light transmitting / receiving unit of the optical radar device, further comprising: a restraining means for restraining the elastic body while compressing the elastic body and allowing a change in the interval between the elastic body and the fixed body.