JPS585209Y2 - receiver - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a light receiver used for position detection of construction machinery, etc.

2. Description of the Related Art When automatically controlling a blade in a construction vehicle such as a bulldozer, a method using a laser beam is widely used.

In this method, a light receiver with multiple light receiving elements arranged vertically is arranged on the blade, and a reference laser beam directed toward a horizontal plane is irradiated, and a predetermined light receiving element of the light receiver always receives this reference laser beam. The height of the blade is controlled in this manner.

In this case, in order for the light receiver to always receive and detect the reference light regardless of the movement of the vehicle, it is necessary to automatically track the light receiver so that it always points toward the light source, or to form a light receiving surface that overlaps the entire circumference. It is necessary.

Conventionally, as a light receiver for automatic tracking, hoods 2a, 2 are provided on both sides of the front surface 1a of the receiver main body 1, as shown in FIG.
b, a partition plate 3 is provided in the center, and the front surface 1a1゜1a2
Light-receiving elements 5 and 6 with a light-receiving angle of ±θ8 are arranged at predetermined positions near the partition plate 3 of When the incident light of
There is a device that allows reference light to be received and detected.

However, in the above-mentioned conventional light receiver, the angle at which light can be received is determined by the directivity angle of the filter 4, and the angle θ at which light can be received is as narrow as 208 degrees, which tends to cause errors in light reception. There were disadvantages such as the difficulty of installing the light receiver and the very complicated structure of the light receiver.

This invention was made with the purpose of eliminating the above-mentioned drawbacks.
An object of the present invention is to provide a light receiver in which a light-receiving range is expanded by arranging a light-receiving element at an angle.

The present invention will be described in detail below with reference to an embodiment of the accompanying drawings.

In FIG. 2, the front surfaces 7 al and 7 a2 of the light receiver 7 are at an angle θ with respect to the central portion 7 b.

The central portion 7b is inclined toward the front.

Then, on the sides of surfaces 7 al and 7 a2, there is a hood 8 a.
, 8b are provided to protrude substantially at right angles to the surfaces ax and 7az, and a support plate 9 is provided in the central portion 7b.
is provided protruding from the front.

The light-receiving elements 5 and 6 are arranged at predetermined positions closer to the center portion 7b of the surfaces 7a1 and 7a2, and the light-receiving surfaces 5a and 5a
are parallel to surfaces 7 at and 7 a2.

Therefore, the normal line n1. of the light receiving elements 5, 6. n2 is the front direction N
with respect to said inclination angle θ.

Only sloping. The light-receiving angle of these light-receiving elements 5.6 is ±08.

Also, the inclination angle θ.

is set to a value smaller than the light-receiving angle θ8.

Therefore, the light receiving element 5 has an incident angle θ8+θ with respect to the front direction N, as shown in FIGS. 2 and 4a.

~-θ8+θ. The incident light Ll is within the range of . L'1 can be detected by light reception.

Further, the light receiving element 6 has an incident angle of −θ8−θ with respect to the front direction N, as shown in FIGS. 2 and 4.

~θ8−θ. It is possible to receive and detect the light beams L2 to L'2 that are incident within the range of .

Therefore, the light receiver 7 has an incident angle θ8+θ. 〜−θ8θ.

It is possible to receive and detect the lights L1 to L2 that are incident within the range of .

Therefore, the light-receiving angle θ of the light receiver 7 is θ-208+2θ as shown in FIG.

Therefore, the light receiving possible angles θ−, 2θ of the light receiver 1 shown in FIG.
2θ for 8.

will be expanded only. Then, the incident angle θ with respect to the front direction N
, (=08-θ.

)~-θ, (=-θ8+θC)
'l-L'2 are incident on both light receiving elements 5 and 6 and detected at the same time.

These light receiving elements 5 and 6 receive a signal e for receiving and detecting incident light.
1. Output e2.

Incidentally, the hoods 8a and 8b have an incident angle θ8+00, -0
8-0.

The length is set so that the light L2 can enter the light receiving elements 5 and 6.

The filters 4, 4' are arranged in front of the light receiving elements 5, 6, and are fixed between the hoods 8a, 8b and the support plate 9.

These filters 4, 4' are for removing harmful rays.

Output signals e0. from the light receiving elements 5 and 6. e2 is added to the amplifier 10.11 of the signal processing circuit 16 shown in FIG.
．． Added to 15.

Then, the incident light has an incident angle θ8+θ.

~θ8−θ. When the light is within the range of , only the light receiving element 5 receives this light and outputs a signal e1.

The light receiving element 6 can receive this light, and the signal e2 (, yoO
, is.

At this time, the tracking signal E1 is sent from the AND circuit 12.
is output.

Also, the incident light has an incident angle of −θ8−θ. When it is within the range of -.theta.8+.theta., only the light receiving element 6 detects the reception of light beyond this point and outputs a signal e2.

The light receiving element 5 can receive this light, and the signal e is O.

At this time, the tracking signal E2 is sent from the AND circuit 13.
is output.

The incident light has an incident angle of θ8-θ. ~-θ8+θ.

When the light receiving element 5°6 is within the range of the signal e1. e
Outputs 2.

Therefore, at this time, neither signal is output from the AND circuits 12 and 13.

That is, the tracking signals El and E2 have an incident angle of θ8+θ as shown in FIG. 4c and d.

~θ8−θ0, −θ8−θ. ~-θ8+θ.

Output when light is incident within the range.

Therefore, these tracking signals E, E2 are applied to, for example, a tracking device (not shown), and while the signal E□ is being applied, the signal E2 is applied to the optical receiver 7 in the direction of the arrow A shown in FIG. By rotating the light receiver 7 in the direction of arrow B while the light is being detected, the light receiver 7 can always follow the incident direction of the light.

As explained above, according to the present invention, the light receiving range can be expanded, and therefore, the attachment of the light receiver can be made very easy.

Moreover, the extremely simple circuit configuration has the advantage that it is possible to provide a light receiver that is easy to use and inexpensive.

[Brief explanation of drawings]

Fig. 1 is a plan view of a conventional optical optical device, Fig. 2 is a plan view showing an embodiment of a photodetector according to the present invention, and Fig. 3 is a plan view of the photodetector shown in Fig. 1 and the photodetector shown in Fig. 2. Diagram showing the light receiving range of the device,
FIG. 4 is an explanatory diagram of the operation of the light receiver shown in FIG. 2, and is a block diagram showing an embodiment of the signal processing circuit of the light receiver shown in FIGS. 5j to 2c. 4.4'...Optical filter, 5,6...
Light receiving element, 7... Light receiver, 8 a, 8 b.
・B...Hood, 9...Support plate, 10゜11・
...Amplifier, 12,13...AND circuit, 14.15...Inverter circuit.

Claims (1)

[Scope of utility model registration request] Two rows of light-receiving means comprising an optical filter having a predetermined directivity angle and a light-receiving element that receives light passing through the optical filter are tilted outward by a predetermined angle smaller than the light-receiving angle on the front surface of the light receiver body. A light receiver characterized in that it is arranged in a.