JPH07159519A - Optical range finding apparatus - Google Patents

Abstract

PURPOSE:To enable accurate distance measurements to be performed based on optical distance data by holding roughly constant the distance between a light-emitting element and a projecting lens and that between the light-emitting element and a receiving lens. CONSTITUTION:A projecting lens 40 is attached to the upper side of a lens holding member 33 with a screw 41 to block passing light 36, and a receiving lens 42 is attached to a base located in the hood portion 37 of a lens holding member 34 so that the lens 42 locates at approximately the same level as the lens 40. A light-emitting circuit including a light-emitting element and a driving circuit tar the element, and a photoreceptive circuit including a photoreceptor 62 and a received-light amplifier, are provided on the respective portions of a light emitting/receiving substrate 53, together with a printed connecting pattern, and the substrate 53 is attached integrally to the holding member 33 by mounting bosses 47, 48 and studs 50,54, together with an arithmetic substrate 49 and a power substrate 57. The distance between the light-emitting element and the lens 40 and the distance between the photoreceptor 62 and the lens 42 can both be held roughly constant, so that accurate distance measurements can be made according to optical distance data about a target.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical distance measuring device for measuring the distance to a target from the timing of projecting light onto the target and the timing of receiving reflected light from the target.

[0002]

2. Description of the Related Art FIG. 3 is a cross-sectional view showing an optical distance measuring device used for a conventional collision prevention warning. In the figure, reference numeral 1 denotes a cylindrical case body having upper and lower ends opened. The back cover 2 is attached to one of the openings, and the glass plate 3 as a transparent light-transmitting plate is attached to the opening of the other end to seal the inside to the outside air.

Further, a light emitting substrate 4 is attached to a part of the inner surface of the back cover 2 in the case body 1, and a light emitting element 5 on the light emitting substrate 4 and a drive for supplying a drive current to the light emitting element 5. Circuits and the like are provided together with a printed connection pattern and the like. The back cover 2 constitutes means for radiating heat from the light emitting element 5.

Further, reference numeral 6 denotes two studs for mounting the board which are erected on the light emitting board 4, and the light from the light emitting element 5 is provided at the upper ends of the two studs 6 for the case body 1. A light projecting lens 7 for projecting light to the outside is attached by a screw or the like. Therefore, the center of the light projecting lens 7 is on the optical axis of the light from the light emitting element 5.

On the other hand, in the case body 1, the back cover 2
A plurality of mounting studs 8 are established on another part of the inner surface, and a large-sized arithmetic / power supply board 9 on which an arithmetic circuit and a power supply circuit are mounted is attached to the upper end of the mounting stud 8. Further, the light receiving board 11 is screwed onto the arithmetic / power supply board 9 through a plurality of mounting studs 10.
It is attached by 2 etc.

Reference numeral 13 denotes two light receiving elements such as a photodiode mounted on the light receiving substrate 11 together with a light receiving amplifier and a printed connection pattern. The light receiving elements 13 have their optical axes aligned with each other. Each one light receiving lens 14 integrated with each other is arranged as shown.

The light receiving lens 14 is the case body 1
The mounting edge 15 protruding from the side plate of the
It is attached in parallel with the arithmetic / power supply board 9 and the light receiving board 11.

Further, numeral 17 is provided between the light receiving lens 14 and the glass plate 3, and is provided from the outside of the case body 1.
The reflected light parallel to the optical axis of the light receiving lens or the like is received by the light receiving element 13
It is a honeycomb filter for leading to. Reference numeral 18 denotes a light shielding wall provided to prevent light emitted from the light emitting element 5 from being reflected on the inside of the case body or the like and directly entering the light receiving element 13.

Reference numerals 19 and 20 denote a calculation / power supply board 9;
A connector that is detachably provided between the light emitting substrate 4 and the light receiving substrate 11, and is used to supply power to each of the light emitting substrate 4 and the light receiving substrate 11 and receive signals from them. It

FIG. 4 is a block connection diagram of an optical distance measuring device used for this collision prevention warning. A drive circuit 21 of the light emitting element 5 is provided on the light emitting substrate 4, and a light receiving substrate 11 receives light. The amplifier 22 is provided together with a print connection pattern and the like.

Further, in FIG. 4, the light emission timing of the light emitting element 5 and the time counter 23 are instructed to start counting on the arithmetic / power supply board 9 also shown in FIG. A light emission start / stop circuit 9A for instructing the time counter 23 to stop counting based on the time, a time counter 23 for measuring the time from the light emission start timing to the light reception start, and a vehicle ahead from this measured time. The microcomputer 24 is provided with a power supply circuit 25 and a microcomputer 24 that outputs an alarm control signal to an alarm device (not shown) according to the calculation result of the distance to the alarm device according to the calculated result of the distance. .

Next, the operation will be described. First, while the vehicle is traveling, the microcomputer 24 receives a power supply voltage from a power supply circuit 25 such as a battery, and the microcomputer 24 inputs a drive signal for pulse emission to the drive circuit 21 via the time counter 23 and the start / stop circuit 9A. . Therefore, the light emitting element 5 receives pulse drive current from the drive circuit 21 and emits pulsed light, and the light projecting lens 7 and the glass plate 3 are emitted.
And the light is projected outside the case main body 1 toward the vehicle which is a target object in front of the own vehicle.

Then, the projected light is radiated and reflected by a part of the vehicle (or a reflector plate) in front of it, and the reflected light is again reflected by the glass plate 3 and the case body 1.
The light is incident on the two light receiving elements 13 via the light receiving lens 14 inside. Then, after this incident signal is amplified by the light receiving amplifier 22, the start / stop circuit 9A is activated, and the count result of the time counter 23 is calculated by the microcomputer 24.
To enter.

In this case, the start / stop circuit 9A sets the light emission timing of the light emitting element 5 by the drive circuit 21 and detects the light receiving timing by the light receiving element 13, and the time between the timing signals is counted by the time counter 23.
Measure at.

Therefore, the microcomputer 24 is
The distance to the front vehicle is obtained from the time obtained from the time counter 23 and, for example, the relative vehicle speed between the own vehicle and the target vehicle, and when the distance becomes smaller than a set value, an alarm is issued. A control signal is output and an alarm is issued from an alarm device or the like to alert the driver.

In such a conventional optical distance measuring device, in order to measure the distance to the target as described above, the light projecting lens 7, the light emitting substrate 4 to which the light emitting element 5 is attached 4, the light receiving lens 14, and the light emission. The light receiving substrate 11 to which the element 13 is attached, the arithmetic / power supply substrate 9, and the like are housed in the case body 1 as described above in order to shorten the wiring of the electric system and facilitate the connection.

[0017]

However, generally, in the conventional device, the overall shape is large, and therefore the vehicle design is not impaired when it is attached to the tip of the vehicle, and the air inlet for cooling the engine is closed. You must install it carefully so that there is no Further, since the glass plate 3 is provided on the front surface of the device, it is necessary to secure a space that can avoid collision and destruction by stones or the like, but it is possible to secure an installation space as the vehicle becomes multifunctional and complicated. It's getting harder.

Further, in the above optical distance measuring device, since each component is arranged in consideration of the wiring of the electric system,
As shown in the figure, an unnecessary dead space is created between the light projecting lens 7 and the glass plate 3 and between the arithmetic / power supply board 9 and the back cover 2. Therefore, this increases the size of the case body 1. However, there is a problem in that it is difficult to mount it on the vehicle.

The invention of claim 1 is made by paying attention to the conventional problems as described above, and the distance between the light emitting element and the light projecting lens and the distance between the light receiving element and the light receiving lens are made substantially constant. By doing so, it is an object of the present invention to obtain an optical distance measuring device capable of accurately performing distance measurement based on optical distance data for a target object.

It is an object of the invention of claim 2 to obtain an optical distance measuring device in which the light emitting / receiving substrate and the arithmetic substrate are arranged close to the lens holding member, so that the storage size in the front-rear direction can be reduced.

It is an object of the invention of claim 3 to provide an optical distance measuring device in which a power transformer can be compactly installed in a case body without securing a storage dimension in a front-rear direction and a left-right direction.

An object of the present invention is to provide an optical distance measuring device capable of efficiently radiating the heat of the light emitting element on the light emitting and receiving substrate from the back side of the light emitting and receiving substrate.

It is an object of the present invention to provide an optical distance measuring device capable of observing the operating condition of the light emitting element without obstructing the light passing through the photometric path.

According to a sixth aspect of the present invention, an optical distance measuring device capable of collectively assembling the light emitting / receiving board, the arithmetic board and the power supply board with respect to the case body by using a lens holding member for holding the light projecting lens and the light receiving lens. The purpose is to obtain the device.

It is an object of the invention of claim 7 to provide an optical distance measuring device which can reduce the size of the case body and facilitate the installation of the case body by suppressing the dead space inside.

[0026]

According to a first aspect of the present invention, there is provided an optical distance measuring apparatus in front of a light emitting / receiving substrate on which a light emitting element and a light receiving element are installed, with respect to each of the light emitting element and the light receiving element. The lens holding member is provided to install the light projecting lens and the light receiving lens while keeping substantially the same distance.

The optical distance measuring device according to the invention of claim 2 is
In front of the light emitting / receiving substrate on which the light emitting element and the light receiving element are installed, there is provided a lens holding member in which the light projecting lens and the light receiving lens are arranged so as to face the light emitting element and the light receiving element, respectively. Between the light emitting element and the light emitting element, there is provided each one transmission hole that forms each photometric path of the light and the reflected light, and an arithmetic circuit board having an arithmetic circuit for the distance to the target object. is there.

An optical distance measuring device according to the invention of claim 3 is
A light emitting / receiving substrate on which a light emitting element and a light receiving element are installed, a transmission hole for forming each photometric path of the light projected from the light emitting element and the reflected light, and an arithmetic circuit for the distance to the target object are provided. And a calculation board, and a power supply board, on which a power transformer is installed, is disposed behind the light emitting and receiving board and on a side of the light emitting and receiving board and the calculation board.

The optical distance measuring device according to the invention of claim 4 is
A synthetic resin on the light emitting and receiving board in the vicinity of the light emitting element, comprising a light emitting and receiving board on which the light emitting element and the light receiving element are installed, and a shield heat dissipation case attached to the rear surface of the light emitting and receiving board where the light emitting element is located. To communicate with
The shield heat radiation case is filled with a synthetic resin having good thermal conductivity.

The optical distance measuring device according to the invention of claim 5 is
A light emitting / receiving substrate on which a light emitting element and a light receiving element are installed, a transmission hole for forming each photometric path of the light projected from the light emitting element and the reflected light, and an arithmetic circuit for the distance to the target object are provided. And a photodiode for detecting light outside the photometric path in the vicinity of the transmission hole on the light projecting side on the front surface of the arithmetic substrate.

The optical distance measuring device according to the invention of claim 6 is
A light emitting / receiving substrate on which a light emitting element and a light receiving element are installed, a transmission hole for forming each photometric path of the light projected from the light emitting element and the reflected light, and an arithmetic circuit for the distance to the target object are provided. And a power supply board disposed behind the light emitting and receiving board and having a power transformer installed so as to be located on the side of the light emitting and receiving board and the operation board. The lens holding member for holding is integrally provided with a mounting boss for fixing each of the light emitting / receiving board, the arithmetic board, and the power supply board via a bush.

The optical distance measuring device according to the invention of claim 7 is
A light emitting and receiving substrate having a light emitting circuit and a light receiving circuit is provided in a case body having a translucent plate attached to an opening, and light is emitted to a target object between the light emitting and receiving substrate and the light emitting lens and the light receiving lens. An arithmetic circuit board having an arithmetic circuit for calculating the distance to the target object based on the timing and the reception timing of the reflected light from the target object is provided, and the power supply circuit is arranged behind the light emitting and receiving circuit board.

[0033]

In the optical distance measuring device according to the present invention, the lens holding member and the light emitting / receiving substrate are simply attached to the set position in the case body, and the position of the light projecting lens with respect to the light emitting element and the light receiving lens with respect to the light receiving element are adjusted. Along with the position, the relationship between these mutual positions is kept constant, which contributes to improvement in accuracy of the distance calculation result to the target object.

In the optical distance measuring device according to the second aspect of the present invention, the dead space between the lens holding member and the light emitting and receiving substrate is provided with a transmission hole and an arithmetic circuit for forming a photometric path which is restricted to a predetermined area. It is effectively used by sandwiching the computing board that it has.

In the optical distance measuring device according to the third aspect of the present invention, the power transformer can be housed in a position that does not hinder the installation of the light emitting / receiving substrate, the arithmetic substrate and the power substrate.

In the optical distance measuring device according to the invention of claim 4, the heat of the light emitting element is efficiently transmitted to the synthetic resin in the shield heat radiating case through the light emitting and receiving substrate, and this heat is further transmitted to the shield heat radiating case. , Enable heat exchange with the atmosphere in contact with the surface.

In the optical distance measuring device according to the invention of claim 5, the light from the light emitting element is captured by the photodiode outside the photometric path, and the output of the photodiode is monitored to detect whether the operation of the light emitting element is normal or abnormal. To be able to judge whether or not.

In the optical distance measuring device according to the sixth aspect of the present invention, the optical distance measuring components are collectively assembled to the case body by integrally connecting the light emitting / receiving substrate, the arithmetic substrate and the power source substrate to the lens holding member in advance. This makes it easy to realize.

In the optical distance measuring device according to the invention of claim 7, a light emitting circuit and a light receiving circuit are provided on the light emitting and receiving substrate, and the light projecting lens and the light receiving lens are at substantially the same level in the vicinity of the light emitting and receiving substrate and the light transmitting plate. By providing an arithmetic circuit board having an arithmetic circuit for calculating the distance to the target object, and by disposing a power supply board behind the light emitting and receiving board,
The width and depth of the case body that stores them can be kept small, the overall shape can be reduced, and an occupied space for mounting on a vehicle can be secured.

[0040]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 31 is a case body in which a glass plate 32 as a translucent plate is attached to one opening and the inside is watertightly sealed, and 33 is a protrusion on the inner wall square of the case body 31 near the glass plate 32. Attached piece 34
The lens holding member is made of a plastic or metal member whose end is supported by the step portion 35.

On the left side of the lens holding member 33, a through hole 36 for passing a light is transmitted, and on the right side, a ring-shaped hood portion 37 extending forward and a cone-shaped blocking portion 38 extending rearward are integrally formed. Is provided in the hood section 3
An optical axis mirror mounting portion 39 is integrally provided on the right side of 7.

Further, 40 is a light projecting lens mounted on the lens holding member 33 by a screw 41 so as to close the through hole 36, and 42 is the light projecting lens at the base of the hood portion 37 of the lens holding member 34. The light-receiving lens is attached so as to be positioned at substantially the same level as the light lens 40.

Further, 43 is an optical interference filter attached to the opening end (front end) of the hood portion 37, and 44 is an optical axis mirror attached to the optical axis mirror attaching portion 39 with a screw 45, which is the main body of the apparatus. It is used for optical axis alignment when it is installed in a vehicle.

Reference numeral 46 denotes a dirt detecting sensor provided on the lens holding member 33 so as to face the glass plate 32 so as not to block the photometric path of the light projecting lens 40. The degree of dirt on the plate 32 is detected, and a signal is output to prompt cleaning.

Further, 47 and 48 are the lens holding members 3
3 Long and short mounting bosses that are integrally projected at multiple locations on the back surface,
49 is a computing board installed at the rear end of the mounting boss 48, and 50 is a mounting hole (not shown) formed in the computing board 49, and a threaded portion 51 at the tip is passed through the mounting boss 48.
Is a stud that is screwed into the screw hole 52 and holds the arithmetic circuit board 49.

Reference numeral 53 designates a light emitting / receiving board installed at the rear end of the stud 50, and 54 is screwed into the bush 56 by passing a threaded portion 55 at the front end into a mounting hole (not shown) formed in the light emitting / receiving board 53. And a stud for holding the light emitting / receiving substrate 53.

Reference numeral 57 is a power supply board installed at the rear end of the stud 54, and 58 is a screw screwed into a screw hole 59 of the stud 54 through a mounting hole (not shown) formed in the power supply board 57. , Power board 57 to stud 5
It is fixed at 4. A part of the power supply board 57 is fixed to the tip of the long boss 47 with a screw 60.

In this way, the arithmetic board 49 and the light emitting / receiving board 5
3 and the power supply board 57 are integrally assembled to the holding member 33 by mounting bosses 47, 48 and studs 50, 54.

The light emitting / receiving substrate 53 has a light emitting element 6
1. Light emitting circuit including the driving circuit thereof and light receiving element 6
2, and a light receiving circuit including a light receiving amplifier is separately provided along with a printed connection pattern and the like, and on the rear surface (back surface) of the light emitting and receiving substrate 53 near the light emitting element 61,
A shield heat radiating case 63 having a synthetic resin 63a having good heat conductivity molded therein is attached. In addition,
The shield heat dissipation case 63 has a part of the peripheral edge (such as a claw).
Is projected upward through a mounting hole provided in the light emitting and receiving substrate 53, and is thermally connected to the light emitting element 61 through the same synthetic resin 63a flowing on the light emitting and receiving substrate 53.
Further, the respective synthetic resins 63a on the upper and lower surfaces of the light emitting / receiving substrate 53 are integrated through the injection holes 53a provided in the light emitting / receiving substrate 53.

Reference numeral 64 is a through hole for projecting light for forming a photometric path, which is provided on the arithmetic board 49 in front of the light emitting and receiving board 53, and has a predetermined size on the optical axis of the light emitting element 61. Has been done. In addition, on the front surface (the surface in the glass plate 32 direction) of the arithmetic board 49, in the vicinity of the transmission hole 64, the light L outside the photometric path passing through the transmission hole 64 from the light emitting element 61 is monitored. A photodiode 65 is provided to detect whether the light emitting element 61 is operating normally. The diameter of the translucent light 64 is set so that, in addition to the light (angle θ) effectively used for photometry, light (angle θ) that illuminates the periphery of the light projecting lens 40 can also pass. .

Reference numeral 66 is a transmission hole for reflected light provided on the arithmetic substrate 49, and the transmission hole 66 is used for the light receiving element 6 described above.
It is arranged at two corresponding parts. Here, the transmission hole 67 at the small-diameter end of the cone-shaped light-shielding portion 38 has the light-receiving element 62.
The light emitted from the light emitting element 61 and reflected by the case body 31 is prevented from directly entering the light receiving element 62.

As the light receiving element 62, one avalanche photodiode having good light receiving sensitivity is used instead of two photodiodes having insufficient sensitivity being arranged in parallel as in the conventional case.

A start / stop circuit for determining the light emitting timing and the light receiving timing is provided at a part of the light emitting / receiving substrate 53, for example, at an intermediate position. On the other hand, the arithmetic board 49 measures the time from the light projecting timing to the light receiving timing that is set and detected under the control of the start / stop circuit, and based on the measurement result by this counter circuit, the vehicle ahead, etc. A microcomputer that calculates the distance to the target object by calculation,
It is provided with a print connection pattern. It should be noted that only the microcomputer related to the arithmetic processing and its peripheral circuits are mounted on the arithmetic board 49. However, since this has no other circuit function, a complicated printed connection pattern can be freely routed. Will be easier.

Further, reference numeral 68 denotes a power supply transformer disposed on the power supply board 57 and between one end of each of the light emitting / receiving board 53 and the arithmetic board 49 and one side plate of the case body 31. A power supply voltage is supplied to each circuit on the light receiving substrate 53 and the arithmetic substrate 49, and a high voltage power is supplied to the light receiving element 62 which is the avalanche photodiode. Reference numeral 70 denotes a watertight electric wire take-out portion used for such purposes as taking out distance measurement data to the outside.

FIG. 2 is a block diagram showing an optical-electrical circuit of the optical distance measuring device. The light emitting / receiving substrate 53 has the light emitting element 61 and a driving circuit 71 for driving the light emitting element 61, the light receiving element 62 and the light receiving element 62. A light receiving amplifier 72 for amplifying the light receiving output thereof and a start / stop circuit 73 for setting and detecting the light projecting timing and the light receiving timing are provided.

Further, the information of the light projecting timing and the light receiving timing is input to the arithmetic board 49, and a time counter 74 for measuring the time between the respective timings, and a target object based on the measurement result of the time counter 74. There is provided a microcomputer 75 for calculating the distance up to. Reference numeral 76 is a power supply circuit including a power supply transformer 68 provided on the power supply board 57.

Next, the operation will be described by taking a vehicle collision prevention as an example. First, while the vehicle is traveling, the microcomputer 75 receives the power supply voltage from the power supply circuit 76, and the microcomputer 75 causes the start / stop circuit 73 to drive the drive circuit 71.
A drive signal is input for light emission. Therefore, the light emitting element 61 receives a drive current from the drive circuit 71, emits light, passes through the light projecting lens 40 and the glass plate 32, and transmits the light outside the case body 31 and in front of the vehicle. Project on a vehicle that is an object.

Then, the projected light is radiated to a part of the vehicle (or a reflector plate) or the like and reflected,
The reflected light is transmitted through the glass plate 32 again, and further, through the light receiving lens 42 in the case body 31, one light receiving element 62 is formed.
Is incident on. Then, this incident signal is received by the light receiving amplifier 72.
After being amplified by, the signal is input to the microcomputer 75 via the start / stop circuit 73 and the time counter 74.

In this case, the start / stop circuit 73 sets and detects the light emitting timing of the light emitting element 61 by the drive circuit 71 and the light receiving timing of the light receiving element 62, and the time between the timing signals is counted by the time counter 7
Measure at 4.

Therefore, the microcomputer 75
From the time obtained from the time counter 61, the distance to the vehicle in front is obtained, and if necessary, a control signal is output to activate the alarm circuit when the distance becomes equal to or less than a set value. Become.

Since the start / stop circuit 73 is installed on the light emitting / receiving substrate 53 side in the present invention, the light emitting element 61 is provided.
The light emission timing and the light reception timing by the light receiving element 62 can be detected with high accuracy without being affected by the line delay, which greatly contributes to the improvement of the distance measurement accuracy.

Further, in such an optical distance measuring device, when the distance measurement as described above is performed, the lens holding member 33 and the light emitting / receiving substrate 53 are simply attached to the set positions in the case main body 31, and the light emitting element 61 is removed. Along with the position of the light projecting lens 40 and the position of the light receiving lens 42 with respect to the light receiving element 62, the relationship between these mutual positions is kept constant, so that the distance detection result to the target object can be obtained without causing variations in the optical axis length. High accuracy can be achieved.

Further, the lens holding member 33 and the light emitting and receiving substrate 5
It is possible to effectively use the dead space between the first and second parts by sandwiching a transmission hole 64 for forming a photometric path restricted to a predetermined region and a calculation substrate 49 having a calculation circuit.

Further, by disposing the power supply board 57 in which the power supply transformer 68 is installed so as to be positioned behind the light emitting and receiving board 53 and on the side of the light emitting and receiving board 53 and the arithmetic board 49, the power supply transformer 68 is provided. Can be stored in a position that does not hinder the installation of the light emitting / receiving board 53, the arithmetic board 49, and the power supply board 57.

Further, a synthetic resin 63 having high thermal conductivity is provided in a shield heat dissipation case 63 attached to the back surface of the light emitting / receiving substrate 53 through an injection hole 53a provided in the light emitting / receiving substrate 53.
By filling a, the same synthetic resin 6 is also poured on the upper surface of the light emitting / receiving substrate 53 so as to cover the outer periphery of the light emitting element 61.
3a and synthetic resin 63a in the shield heat dissipation case 63
The heat of the light emitting element 61 can be transmitted to the shield heat dissipation case 63 through the heat dissipation element 63 to exchange heat with the atmosphere in contact with the surface of the shield heat dissipation case 63.

Further, by providing a photodiode 65 for detecting light outside the photometric path in the vicinity of the transmission hole 64 on the light projecting side of the arithmetic circuit board 49, the light from the light emitting element 61 can be captured by the photodiode 65. By monitoring the output of the photodiode 65, it is possible to determine whether the operation of the light emitting element 61 is normal or abnormal.

Further, the lens holding member 33 for holding the light projecting lens 40 and the light receiving lens 42 is attached to fix the light emitting / receiving board 53, the arithmetic board 49 and the power supply board 57 via the bushes 50, 54. Boss 4
By integrally providing the optical distance measuring components 7 and 48, the light emitting / receiving substrate 53, the arithmetic substrate 49, and the power source substrate 57 for the lens holding member 33 can be collectively assembled to the case body 31.
It can be easily realized in the integrally connected state.

A light emitting circuit and a light receiving circuit are provided on one light emitting and receiving substrate 53, and the light emitting and receiving substrate 53 and the light transmitting plate 3 are provided.
In the vicinity of 1, a calculation board 49 having a microcomputer 75 as a calculation circuit for calculating the distance to the target object is provided between the light projecting lens 40 and the lens holding member 33 to which the light receiving lens 42 is attached at substantially the same level. ,
Further, by disposing the power supply board 57 behind the light emitting / receiving board 53, the width and depth of the case body 31 for accommodating them is suppressed to a small size, and the overall shape is miniaturized. It is possible to secure an occupied space for mounting on.

Further, in the present invention, the case body 31 is provided with an opening on only one surface, and the glass plate 32 is watertightly attached to the opening, so that the case body 31 has a structure as compared with the conventional case having a back cover. The watertightness of the inside becomes more reliable.

In each of the above-described embodiments, the method of obtaining the distance to the preceding vehicle in order to prevent the collision of the vehicle has been described, but the present invention is not limited to this and can be widely used for measuring the distance between all moving objects.

[0071]

As described above, according to the invention of claim 1, in front of the light emitting / receiving substrate on which the light emitting element and the light receiving element are installed, the light emitting element and the light receiving element are disposed at substantially the same distance from each other. Since the lens holding member for holding the light projecting lens and the light receiving lens is provided, the target is achieved by making the distance between the light emitting element and the light projecting lens and the distance between the light receiving element and the light receiving lens substantially constant. There is an effect that what can accurately measure the distance based on the optical distance data to the object can be obtained.

According to the second aspect of the present invention, the lens holding is provided in front of the light emitting / receiving substrate on which the light emitting element and the light receiving element are installed, in which the light projecting lens and the light receiving lens are arranged so as to face the light emitting element and the light receiving element, respectively. A member is provided, and between the lens holding member and the light emitting / receiving substrate, one transmission hole that forms each photometric path of the light projected from the light emitting element and the reflected light, and the distance to the target object. Since the arithmetic circuit board provided with the arithmetic circuit is provided, by arranging the light emitting / receiving board and the arithmetic circuit board in close proximity to the lens holding member, there is an effect that the storage dimension in the front-rear direction can be reduced.

According to the invention of claim 3, a light emitting / receiving substrate on which the light emitting element and the light receiving element are installed, and one transmission hole forming each photometric path of the light projected from the light emitting element and the reflected light, And a calculation board provided with a calculation circuit for calculating the distance to the target, and a power supply board having a power transformer installed behind the light emitting and receiving board and on the side of the light emitting and receiving board and the calculation board. Since the power transformers are arranged, the power transformer can be compactly installed in the case body without securing sufficient storage dimensions in the front-rear direction and the left-right direction.

According to the invention of claim 4, the light emitting and receiving board for mounting the light emitting element and the light receiving element, and the shield heat radiating case attached to the rear surface of the light emitting and receiving board at the position where the light emitting element is present are provided. Since the shield heat dissipation case is filled with a synthetic resin having good thermal conductivity so as to communicate with the synthetic resin on the light emitting / receiving substrate around the light emitting element, the heat of the light emitting element on the light emitting / receiving substrate is generated. There is an effect that what can efficiently dissipate heat from the back of the light receiving substrate is obtained.

According to the invention of claim 5, a light emitting / receiving substrate on which the light emitting element and the light receiving element are installed, and one transmission hole forming each photometric path of the light projected from the light emitting element and the reflected light, And a calculation board provided with a calculation circuit for the distance to the target, and a photodiode for detecting light outside the photometric path is provided in the vicinity of the transmission hole on the light projecting side on the front surface of the calculation board. Therefore, there is an effect that the operation state of the light emitting element can be observed without obstructing the light passing through the photometric path.

According to the invention of claim 6, a light emitting / receiving substrate on which the light emitting element and the light receiving element are installed, and one transmission hole forming each photometric path of the light projected from the light emitting element and the reflected light, And a calculation board provided with a calculation circuit for the distance to the target, and a power supply board disposed behind the light emitting and receiving board and having a power transformer installed so as to be located on the side of the light emitting and receiving board and the calculation board. The lens holding member for holding the light projecting lens and the light receiving lens is integrally provided with a mounting boss for fixing each of the light emitting / receiving board, the arithmetic board, and the power supply board via a bush. Therefore, it is possible to obtain the one in which the light emitting / receiving board, the arithmetic board, and the power supply board for the case body can be assembled together by using the lens holding member that holds the light projecting lens and the light receiving lens. There is.

According to the invention of claim 7, one light emitting and receiving substrate having a light emitting circuit and a light receiving circuit is provided in the case body having a light transmitting plate attached to the opening, and the light emitting and receiving substrate, the light projecting lens, and An arithmetic circuit board having an arithmetic circuit for calculating the distance to the target object is provided between the light receiving lens and the light source timing to the target object and the light reception timing of the reflected light from the target object. Since the power supply circuit is arranged, there is an effect that the size of the entire case body can be reduced and the case body can be easily installed by suppressing the dead space inside.

[Brief description of drawings]

FIG. 1 is a plan sectional view showing an optical distance measuring device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing an optical-electrical circuit of the optical distance measuring device of the present invention.

FIG. 3 is a plan sectional view showing a conventional optical distance measuring device.

4 is a block diagram showing an optical-electrical circuit of the optical distance measuring device in FIG.

[Explanation of symbols]

 31 Case Main Body 32 Glass Plate (Transparent Plate) 33 Lens Holding Member 40 Light Emitting Lens 42 Light Receiving Lens 47, 48 Mounting Boss 49 Calculation Board 50, 54 Bushing 53 Light Emitting / Receiving Board 57 Power Supply Board 61 Light Emitting Element 62 Light Receiving Element 63 Shield Heat Dissipation Case 63a Synthetic resin 64, 66 Transmission hole 65 Photodiode 68 Power transformer 75 Microcomputer (arithmetic circuit)

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[Procedure amendment]

[Submission date] December 14, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Figure 3]

[Fig. 2]

[Figure 4]

Claims (7)

[Claims] 1. The light from a light emitting element is projected onto a target object through a light projecting lens, the reflected light from the target object is received, and the distance to the target object is measured based on the projection timing and the reception timing. In the optical distance measuring device, the light emitting and receiving substrate on which the light emitting element and the light receiving element are installed, and the light emitting and receiving substrate are arranged in front of the light emitting and receiving substrate to keep the light emitting element and the light receiving element at substantially the same distance from each other. And a lens holding member on which a light-receiving lens and a light-receiving lens are installed. 2. The light from the light emitting element is projected onto a target object through a projection lens, the reflected light from the target object is received, and the distance to the target object is measured based on the projection timing and the reception timing. In the optical distance measuring device, the light emitting and receiving substrate on which the light emitting element and the light receiving element are installed, and the light projecting lens and the light receiving lens which are arranged in front of the light emitting and receiving substrate and face the light emitting element and the light receiving element, respectively. A lens holding member in which a lens is arranged, and one transmission hole that is arranged between the lens holding member and the light emitting and receiving substrate and forms each photometric path of the light projected from the light emitting element and the reflected light, And an arithmetic board provided with an arithmetic circuit for calculating the distance to the target. 3. The light from the light emitting element is projected onto a target object through a projection lens, the reflected light from the target object is received, and the distance to the target object is measured based on the projection timing and the reception timing. In the optical distance measuring device, the light emitting / receiving substrate on which the light emitting element and the light receiving element are installed, the respective transmission holes forming the photometric paths of the light projected from the light emitting element and the reflected light, and the target. An arithmetic board provided with an arithmetic circuit for a distance to an object, and a power supply board disposed behind the light emitting / receiving board and having a power transformer installed so as to be located on the side of the light emitting / receiving board and the arithmetic board. An optical distance measuring device characterized in that 4. The light from the light emitting element is projected onto a target object through a projection lens, the reflected light from the target object is received, and the distance to the target object is measured based on the projection timing and the reception timing. In the optical distance measuring device, the light emitting / receiving board on which the light emitting element and the light receiving element are installed, the shield heat dissipation case attached to the rear surface of the light emitting / receiving board where the light emitting element is located, and the light emitting / receiving board around the light emitting element. An optical distance measuring device comprising: a synthetic resin having good thermal conductivity, which is filled in the shield heat dissipation case through a front surface of the light receiving substrate and an injection hole provided in the light emitting and receiving substrate. 5. The light from the light emitting element is projected onto a target object through a projection lens, the reflected light from the target object is received, and the distance to the target object is measured based on the projection timing and the light reception timing. In the optical distance measuring device, the light emitting / receiving substrate on which the light emitting element and the light receiving element are installed, the respective transmission holes forming the photometric paths of the light projected from the light emitting element and the reflected light, and the target. An optical measurement device comprising an arithmetic circuit board provided with an arithmetic circuit for a distance to an object, and a photodiode for detecting light outside the photometric path in the vicinity of the transmission hole on the front side of the arithmetic circuit board on the light projecting side. Distance device. 6. The light from the light emitting element is projected onto a target object through a light projecting lens, the reflected light from the target object is received, and the distance to the target object is measured based on the projection timing and the light reception timing. In the optical distance measuring device, the light emitting / receiving substrate on which the light emitting element and the light receiving element are installed, the respective transmission holes forming the photometric paths of the light projected from the light emitting element and the reflected light, and the target. An arithmetic board provided with an arithmetic circuit for a distance to an object; a power supply board disposed behind the light emitting and receiving board and having a power transformer installed so as to be located on the side of the light emitting and receiving board and the arithmetic board; A lens holding member for holding the light projecting lens and the light receiving lens, and integrally having a mounting boss for fixing each of the light emitting and receiving board, the arithmetic board and the power supply board via a bush. An optical distance measuring device characterized by being provided. 7. A case main body having a translucent plate attached to an opening, and a single light emitting and receiving substrate provided in the case main body and having a light emitting circuit including a light emitting element and a light receiving circuit including a light receiving element. A light projecting lens which is provided in the case body in the vicinity of the light transmissive plate and projects light from the light emitting element to a target object outside the case body through the light transmissive plate; and reflected light from the target object. A light-receiving lens that receives light through a light-transmitting plate, and a light-emitting lens that is disposed between the light-emitting and receiving substrate and the light-projecting lens and the light-receiving lens and that has a transmission hole for the light projection and reflected light Based on the projection timing of and the light reception timing of the reflected light by the light receiving element, an arithmetic circuit board mounted with an arithmetic circuit for calculating the distance to the target object, and the arithmetic circuit board disposed behind the light emitting and receiving board. An optical distance measuring device comprising: a light emitting / receiving board; and a power board on which a power supply circuit for supplying power to each circuit of the arithmetic board is mounted.