JPS6113637B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a punch hole detection device for detecting a punch hole made in a detection object using light.

Conventionally, there have been detection devices of this type as shown in FIGS. 1 to 3. That is, the illustrated device is arranged so that the light beam emitted by the projector 1 is detected by the receiver 2 with a detection field of view W, and the moving detection object 3 is arranged so that the light beam emitted by the projector 1 is detected by the receiver 2. When the detected object 3 is interposed between
The punch hole 4 is detected. As shown in the front view of FIG. 1 and the side view of FIG. 2, the emitted light beam from the projector 1 is blocked by the detection object 3. The emitted light beam from the projector 1 passes through the punch hole 4 and is received by the light receiver 2, and the presence of the punch hole 4 in the detection object 3 is detected.

However, in the conventional punch hole detection device, when the detection object 3 meanders and reaches the state shown in FIG. Light passes through from the end and is detected by the light receiver 2. That is,
Even if there is no punch hole 4, if the detection object 3 has a large meandering, the light receiver 2 will detect the leakage flux due to the meandering, so it is not possible to accurately detect the presence or absence of the punch hole 4 in the detection object 3. There were flaws.

The present invention has been made in order to eliminate the drawbacks of the conventional ones as described above, and it divides the light receiver to provide at least two detection fields of view, and also includes an edge detector for detecting the edge of a meandering detection object. logic for inputting the output signals of the end detector and the light receiver to exclude the detection field of the light receiver that receives the leakage light flux due to meandering and select the detection field of the other light receiver as valid; It is an object of the present invention to provide a punch hole detection device that can accurately detect punch holes in a detection object by providing a circuit.

Hereinafter, one embodiment of the present invention will be explained based on FIGS. 4 and 5. In the figures, 2A and 2B indicate independent detection fields of view W _A and W _B by dividing the conventional light receiver 2. These light receivers 2A and 2B are provided with light receivers 20A and 20B that receive the emitted light beams from the light projectors 10A and 10B that are arranged in parallel with the light projector 1.
Both ends of the detection object 3 are detected by A and 20B. In addition, 5 indicates each light receiver 2A, 2
This logic circuit 5 receives the output signals of the light receiver 2A and the inverted signal of the light receiver 20A, and the logic circuit 5 receives the output signals of the light receiver 2A and the inverted signal of the light receiver 20A, and the It is composed of an AND element 6B which inputs the signal and an inverted signal of the output signal of the light receiver 20B, and an OR element 7 which inputs the output signals of these AND elements 6A and 6B. When the detection field of view W A of the light receiver 2A is blocked, the detection field of view W _A of the light receiver 2A is selected as valid, and similarly, when the light receiver 20B is blocked, the detection field of view W _B of the light receiver 2B is selected as valid.

Therefore, according to the punch hole detection device having the above configuration, the detection object 3 is the light projector 1, 10.
Of course, if the punch hole 4 is located at a regular position that blocks the emitted light flux from A and 10B, it is possible to accurately detect the punch hole 4 in the same way as a conventional punch hole detection device. Due to the meandering of the punch hole 4, it is possible to reliably detect the punch hole 4 even when the emitted light beam from the projector 1, 10A or 10B passes from the edge of the detection object 3. That is, first, as shown in FIG.
When the detection object 3 is located at a proper position that blocks the radiation beam from the projectors 1, 10A, and 10B, the radiation beam from the projector 1 is blocked by the detection object 3, but there is a punch hole in the detection object 3. 4
Therefore, the light receiver 2B receives the radiation beam passing through the punch hole 4. Therefore, in this case, only the light receiver 2B will output, and the output signal (logical value 1) of this light receiver 2B and the light receiver 2B will be output.
The output of the AND element 6B, which receives the inverted signal (logical value 1) of the output signal 0B (logical value 0), obtains a logical value 1. On the other hand, the AND element 6A is connected to the light receiver 2A.
The output signal (logical value 0) of the optical receiver 20A and the inverted signal (logical value 1) of the output signal (logical value 0) of the light receiver 20A are input, and a logical value 0 is output. Furthermore, an OR element 7 receives the output signals of these AND elements 6A and 6B.
At this time, it outputs a logical value of 1 and detects that there is a punch hole 4 in the detection object 3.

Next, as shown in FIG. 5, when the detection object 3 meanders, the meandering causes the light receiver 2A to receive the emitted light beam from the emitter 1. The receiver 20A for detecting the light source also receives the emitted light beam from the emitter 10A, and therefore the output signal of the receiver 2A (logical value 1) and the inverted signal (logical value) of the output signal of the receiver 20A 0), the output of the AND element 6A has a logic value of 0. In other words, in this case, the receiver 2
It is detected that the received light A is not received by the punch hole 4 of the detection object 3, but a leaked light beam is received due to meandering, and no erroneous output occurs. On the other hand, receiver 2
B is the light emitter 1 due to the punch hole 4 of the detection object 3.
Furthermore, since the light receiver 20B for detecting the end of the detection object 3 is always blocked by the detection object 3 and does not receive the radiation light flux from the projector 10B, the light receiver 2B AND element 6B which inputs the output signal (logical value 1) of the output signal of the optical receiver 20B and the inverted signal (logical value 1) of the output signal of the photoreceiver 20B.
The output of is a logic 1. Therefore, the logical sum element 7 which inputs the outputs of these logical product elements 6A and 6B outputs a logical value of 1, thereby detecting the detected object 3.
To accurately detect a punch hole 4 of. That is, in the above description, the logic circuit 5 composed of the AND elements 6A, 6 and the OR element 7 excludes the detection field of view W A of the light receiver 2A which receives the leaked light flux by meandering, and detects the detection field W _A of the light receiver 2A which receives the leaked light flux by meandering. The detection field of view W _B of 2B is selected as valid. Furthermore, in Figure 5,
For example, if the detection object 3 does not have a punch hole 4, the light receiver 2B will not receive the emitted light beam from the emitter 1, and even if the light receiver 2A receives a leaked light beam due to meandering, the output of the logic circuit 5 will be 0. It will be easily understood that the absence of the punch hole 4 is detected.

Note that in the above embodiment, in order to detect the edge of the detection object 3, the light projectors 10A, 10B and the light receiver 20 are used.
A, 20B are the emitter 1 and the receiver 2A, respectively.
It was installed in parallel to 2B and detected by light, but
Other methods such as mechanical limit switches can also be used for detection. In addition, the floodlights 1, 10A, 1
By providing 0B integrally and expanding its light projection area, the same effects as in the embodiment can be obtained.

As described above, according to the punch hole detection device of the present invention, the light receiver is divided to provide at least two detection fields of view, the edge detector is provided, and the outputs of the light receiver and the edge detector are provided. A logic circuit is provided that excludes the detection field of the receiver that receives the leakage light flux due to meandering by receiving a signal and selects other detection fields as valid, so when the width of the detection object is narrow and the amount of meandering is large. However, punch holes can be detected accurately without malfunction.

[Brief explanation of the drawing]

Figures 1 to 3 are configuration diagrams showing a conventional punch hole detection device. Figure 1 is a front view showing a state in which a detection object is inserted at a normal position, and Figure 2 is a side view of Figure 1. 3 are front views showing a meandering state of the detection object. 4 and 5 are configuration diagrams showing a punch hole detection device according to an embodiment of the present invention, and FIG. The figure is a front view showing a meandering state of the detection object. 1, 10A, 10B... Floodlight, 2A, 2B,
20A, 20B...Receiver, W _A , W _B ...Detection field of view, 3...Detection object, 4...Punch hole, 5...
...Logic circuit, 6A, 6B...AND element, 7...
Disjunctive element. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A device comprising a light emitter and a light receiver provided opposite to the light emitter to receive the radiation beam emitted from the light emitter, and a punch hole of a detection object moving between the emitter and the light receiver. In the punch hole detection device, the light receiver is divided to provide at least two detection fields of view, and two edge detectors are provided to detect the edges of the meandering detection object, and the edge detection The device is characterized by a logic circuit that receives output signals from the light receiver and the light receiver to exclude the detection field of the light receiver that receives the leaked light flux due to meandering, and selects the detection field of other light receivers as valid. Punch hole detection device. 2. The punch-hole detection device according to claim 1, wherein the edge detector comprises a light receiver or a mechanical limit switch. 3. The light receiver is composed of two light receivers, and a logic circuit is provided for each light receiver and outputs an inverted signal of the output signal from the edge detector and an output signal of the paired light receiver to the edge detector. 3. The punch hole detection device according to claim 1, comprising: an AND element that inputs an AND element; and an OR element that inputs an output signal of these AND elements.