JPS61230070A - Subject detector - Google Patents

Abstract

PURPOSE:To widen the width of an area where a subject can be detected by providing a light receiving reflecting mirror and a light projecting reflecting mirror so that they can face a light receiving part and a light projecting part and swinging them while the prescribed angle relation is maintained. CONSTITUTION:The light projecting part 20 and the light receiving part 22 are installed at a position where a light beam from the light projecting part will not directly enter the light receiving part 22. Moreover the light projecting reflecting mirror 24 and the light receiving reflecting mirror 30 are provided so that they can face the light projecting surface of the light projecting part 20 and the light receiving surface of the light receiving part 22, and their optical axes 24a and 30a are set so as to intersect at the prescribed angle. Both reflecting mirrors 24 and 30 are swung or rotated while the prescribed angles of them are maintained by drive parts 36, 38 and 40. Thus both reflecting mirrors 24 and 30 are driven at a high speed, thereby widening substantially the width of the subject detecting area.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an object detection device, and in particular, when light from a light projecting section is reflected by an object to be detected, the reflected light is received by a light receiving section and detected. The present invention relates to a reflective object detection device.

[Prior art]

Conventionally, the above-mentioned reflective object detection device has a
There is one disclosed in Japanese Patent No. 28350. As shown in FIG. 8, a light projecting section 2 and a light receiving section 4 are provided such that their optical axes form a predetermined angle with respect to a floor surface 6 and intersect with each other.

Note that 8 is a light projecting area and 10 is a light receiving area.

In this device, if there is an object to be detected in the area where the light emitting area 8 and the light receiving area 10 overlap, that is, the shaded area in FIG. The reflected light is received by the light receiving unit 4, and the object to be detected is detected. The range indicated by symbol A in the figure is the detection width.

[Problem that the invention seeks to solve]

In this device, the optical axes of the light emitting part 2 and the light receiving part 4 intersect, so the light receiving part 4 does not receive light reflected from objects other than the small object to be inspected, such as floors and walls, and false detection There's nothing to do. However, there was a problem that the detection width A was narrow due to the above-mentioned reason.

This detection width A is such that the optical axis of the light emitter 2 and the light receiver 40 is at the floor surface 6.
Even if the light emitting area 8 and the light receiving area 10 are widened by changing the angle between them, they will not become much wider. The fact that the detection width A is narrow causes a big problem when the above-mentioned device is used in a device that requires a wide detection width, such as a security device or an automatic door opening/closing device.

[Means to solve problems]

A means for solving the above problems includes a light projecting section and a light receiving section arranged so as not to directly receive the light from the light projecting section. A light projecting reflector is provided to face the light projecting surface of the light projecting section. Furthermore, a light-receiving reflector is provided so as to face the light-receiving surface of the light-receiving section.
The optical axis of this light-receiving reflector intersects the optical axis of the light-projecting reflector at a predetermined angle. A drive unit is provided for swinging or rotating both reflecting mirrors while maintaining a state in which both optical axes form the above-mentioned predetermined angle.

[For production]

In such a means, since the optical axes of the light projecting part and the light receiving part intersect, a narrow detection area is formed as in the conventional one shown in FIG. This detection area is moved sequentially in the width direction of the detection area because both reflecting mirrors are swung or rotated by the drive unit with their optical axes forming a predetermined angle.

Therefore, if this moving speed is made sufficiently fast, the detection range will be substantially expanded, and the above-mentioned problems and points can be solved.

〔Example〕

A first embodiment is shown in FIGS. 1 to 3. This embodiment has an envelope 12 as shown in FIGS. 1 and 2.

This envelope 12 has its upper surface attached to a ceiling 14, and its interior is divided into front and rear sections by partition walls 16, as shown in FIG.

A support stand 18 is attached to the front side of the partition wall 16, and a light projector 20 and a light receiver 22 are mounted on this support stand 18.
The envelope 12 is attached so that its optical axis runs along the length direction of the envelope 12, and the light projecting surface and the light receiving surface are oriented in opposite directions.

A light projecting reflector 24 is arranged to face the light projecting surface of the light projecting unit 20.
is located. The reflecting mirror 24 is connected to a driven shaft 26, and the driven shaft 26 is rotatably supported by a bearing 28 provided on the rear side of the partition wall 16.

Similarly, a light-receiving reflecting mirror 30 is arranged to face the light-receiving surface of the light-receiving section 22, and this reflecting mirror 30 is directed from a rotary actuator 32 provided on the rear side of the partition wall 16 to the front of the partition wall 16. It is coupled to a protruding drive shaft 34. This rotary actuator 32 is connected to the light receiving reflecting mirror 3.
0 is oscillated or rotated.

A drive member 36 having an oval side shape is connected to the driven shaft 2G so as to form an angle α with the light projecting reflector 24, and a similar drive member 38 is connected to the light receiving reflector 24 on the drive shaft 34. 30 so as to form an angle β.

A wire 40 is stretched between both drive members 36, 38, and these drive members 36, 38 and wire 40 form a parallel link mechanism. Note that 42 is a light projecting window, and 44 is a light receiving window, which are provided at positions corresponding to the light projecting reflecting mirror 24 and the light receiving reflecting mirror 30 on the lower surface of the envelope 12. Further, the drive members 36 and 38 do not have to have an oval-shaped side surface, but may have a disc-shaped side surface, for example.

When both drive members 36.38 are in the vertical state as shown in FIG.
intersect at a predetermined angle. Therefore, the detection area at this time has a distance and a width A, as shown by reference numeral 46a in FIG. Note that 47 is the light projecting area at that time, and 48 is the light receiving area at that time.

In this state, when the rotary actuator 32 is operated to rotate the drive member 38 counterclockwise, the light receiving reflector 30 is rotated counterclockwise.

This rotation is transmitted to the drive member 36 via the wire 40, the drive member 36 rotates counterclockwise, and the light projecting reflector 2
4 also rotates counterclockwise. At this time, both reflecting mirrors 24.
Since the 300 rotation angles are equal, both optical axes 24a.

The angle formed by 30a does not change, and the size of the detection area does not change and moves toward the position indicated by reference numeral 46b. Thereafter, it moves toward the detection area 460 in the same manner. If the rotary actuator 32 is one that swings the light-receiving reflecting mirror 30, the detection area moves from 46c to 46b and then to 46&. Repeat this below. Also,
If the rotary actuator 32 is one that rotates the light-receiving reflector 30 once, the detection area will be from 46c to
It jumps to 46a, moves to 46a, 46b, and 460, and repeats this process.

If the moving speed of this sensing area is made sufficiently faster than the moving speed of the object to be detected, the sensing range becomes equivalent to a distance L and a sensing width B.

A second embodiment is shown in FIGS. 4 and 5. This embodiment differs from the first embodiment in that the parallel link mechanism is made up of drive members 36, 38 and wires 40, whereas it is made up of arms 49, 50 and links 51. Since the other parts are configured in the same manner as in the first embodiment, the same reference numerals are given and the explanation will be omitted. This embodiment also operates in the same manner as the first embodiment. .

A third embodiment is shown in FIGS. 6 and 7. This embodiment uses one rotary actuator and a parallel link mechanism to swing or rotate the light projecting reflector 24 and the light receiving reflector 30 in the first and second embodiments. , a rotary actuator 52 for the light emitting reflector 24 and a rotary actuator 54 for the light receiving reflector 30 are provided, and these two rotary actuators 52 and 54 are operated synchronously to swing the both reflectors 24 and 30. Something that moves or rotates.

Since the other parts are configured similarly to the first embodiment,
The same reference numerals are used to omit the explanation. This embodiment also operates in the same manner as the first embodiment.

〔effect〕

As described above, the present invention moves an extremely narrow area other than the object to be detected by swinging or rotating two reflecting mirrors without changing the angle formed by their optical axes. . Therefore, the detection area can be equivalent to one with a sufficiently wide detection width by appropriately selecting the moving speed. Therefore, it is suitable for devices such as automatic door opening/closing devices and security devices that require an object detection device with a wide detection range without false detection.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional front view of a first embodiment of the object detection device according to the present invention, FIG. 2 is a cross-sectional plan view of the first embodiment, and FIG. 3 is a detection area of the first embodiment. A diagram showing the movement state,
FIG. 4 is a cross-sectional plan view of the second embodiment, and FIG. 5 is a cross-sectional plan view of the second embodiment.
FIG. 6 is a cross-sectional plan view of the third embodiment, FIG. 7 is a vertical front view of the third embodiment, and FIG. 8 is a schematic cross-section of a conventional object detection device. It is a diagram. 20... Light projecting section, 22... Light receiving section, 24... Light projecting reflector, 30... Light receiving reflector, 32.36.38
．． 40.46.48.50.52.54... Drive unit. Patent applicant: Japan Air Brake Co., Ltd. Honda Electronics Co., Ltd.

Claims (1)

[Claims] (1) a light projecting section, a light receiving section arranged so as not to directly receive the light from the light projecting section, and a light projecting reflector provided to face the light projecting surface of the light projecting section; A light-receiving reflector provided so as to face the light-receiving surface of the light-receiving section and whose optical axis intersects the optical axis of the light-emitting reflector at a predetermined angle; An object detection device comprising: a drive section configured to rotate or swing the optical axis while maintaining the above angle.