JPH0129662Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial Application Field" The present invention relates to a counting device using a photoelectric sensor that is convenient for counting items with lead foot lines and small items without lead foot lines. .

``Prior art'' Generally, to count the number or determine the size of electronic parts, etc., a light emitter/receiver is used, and the light is passed through the space between the light emitters and receivers, and the slight changes in the amount of light at that time are detected. It is being done.

``Problems to be solved by the invention'' However, conventional counting devices input a received light signal proportional to the amount of light received by the photoreceiver to a comparator, and the comparator compares it with a certain reference level to calculate the amount of light received by the photoreceiver. A pulse-like counting signal is output every time the lead wires change, so when counting parts with lead wires, two or more parts with intertwined lead wires are The light amount change corresponding to the lead foot line and the light amount change corresponding to the intertwined lead foot lines are so close that they cannot be distinguished, so one or three intertwined lead foot lines are counted. In order to prevent this, reducing the sensitivity of circuits such as comparators and amplifiers that output pulse-like counting signals in response to changes in light intensity will result in changes in light intensity corresponding to the element part of the part. There were cases in which parts with small shapes could not be counted due to the weakness of the parts, or omissions in counting of individual parts occurred depending on the feeding conditions. Conversely, if you increase the sensitivity of circuits such as comparators and amplifiers, the light reception signal from the photoreceiver that is input to the comparator will be proportional to the size of the shape of the object to be counted. If the ratio of the size of the element part of the part and the lead foot line protruding from the element part of the part is gradually approaching, and the lead foot lines of two or more parts overlap, or 2
When the lead lines of two or more parts are intertwined and input, even though there are two or more parts, the lead lines are intertwined with the change in light amount corresponding to the element part of each part. Because the values of the changes in light intensity are so close that they cannot be distinguished, or conversely, lead foot lines that are intertwined are often counted and miscounted as three or more parts. I had a problem.

Therefore, in view of the above-mentioned circumstances, the present invention has developed a parabolic curve and an exponential curve that can freely switch the characteristics of the input signal input to the comparator in response to the light reception signal received and output by the light receiver to match the shape of the object to be counted. However, in the case of irregularly shaped objects to be counted that have lead foot lines, if you switch to the characteristic that exhibits an exponential curve, the signal input to the comparator will be large compared to the element part of the part, and will be larger than the lead foot line. It can be made smaller, and even if the lead lines of two or more parts are intertwined, the number can be counted accurately. Also, for small parts, if you switch to a characteristic that exhibits a parabolic curve, the number of parts can be counted accurately compared to the shape. The purpose of the present invention is to provide a counting device using a photoelectric sensor that can input a large signal to a comparator, eliminate erroneous counting, and improve counting accuracy.

"Means to be Solved by the Invention" In order to achieve the above object, the present invention uses a photoelectric sensor that counts the change in the amount of light when an object passes between the emitter and receiver by comparing it with a reference level of a comparator. In the counting device used, the relationship between the output signal and the input signal proportional to the amount of light received by the light receiver is switched between a parabolic curve and an exponential curve between the light receiver and the comparator. It is characterized by a counting device using a photoelectric sensor with a flexible conversion amplifier interposed.

``Example'' An example of a counting device using a photoelectric sensor according to the present invention will be described below with reference to the drawings. In FIG. 1, 1 is an oscillation circuit that outputs a 7.5KHz drive signal, and 2 is an oscillation circuit that outputs a 7.5KHz drive signal.
The light emitter 3 emits visible light, infrared rays, or laser light modulated at 7.5 KHz, and the light receiver 3 is composed of a phototransistor or the like that receives the emitted light from the light emitter 2. An input section is formed between the light emitter 2 and the light receiver 3 so that parts such as a transistor can pass therethrough while cutting off the light emitted from the light emitter 2. A conversion amplifier 4 is connected to the photoreceiver 3. As shown in FIGS. 2 and 5, the conversion amplifier 4 consists of a nonlinear circuit 5 and a comparator 6. The nonlinear circuit 5 is connected to the input terminal (-) of the comparator 6, and the input terminal of the comparator 6 The connection can be changed between the (-) and output terminals. This connection change is
This is done by the switching device 7. The nonlinear circuit 5 includes resistors R _1-1 to _{R 1-o} , as shown in FIG.
It consists of _R2-1 ~ _R2-o , _R3-1 ~ _R3-o and diodes _D1 ~ _Do , and each resistor _R1-1 ~ _R1-o , _R2-1 ~
The diodes D ₁ to D _o are turned ON in sequence according to the input voltage depending on the values of R _2-o and R _3-1 to _{R 3-o} . The conversion amplifier 4 is connected to a bandpass filter 8 that passes a 7.5KHz signal. An output circuit 10 for displaying or printing out counts is connected to the bandpass filter 8 via a comparator 9 for optical level compensation. The optical level compensating comparator 9 is constructed as in the device disclosed in Utility Application No. 120833/1983, which was previously filed by the applicant of the present invention. That is, the light level compensation comparator 9 consists of a passing object signal removal circuit, a sample hold circuit, and a comparator. A hold circuit samples and holds a signal from which changes in light amount have been removed at regular time intervals, and the reference voltage value of the comparator is varied using the held value. Therefore, the amount of light emitted by the light emitter 2,
Even if the characteristics of the circuit configuration of the light receiver 3 etc. change over time, such as deterioration over time, stable counting operation is always performed by changing the reference voltage of the comparator. Further, a display device 12 is connected to the bandpass filter 8 via an optical level down comparator 11. Light level down comparator 1
1 consists of a passing object signal removal circuit and a comparator similar to the above, and the output signal from the passing object signal removal circuit, that is, the output signal corresponding to the deterioration of the characteristics of the preceding stage circuit including the light emitter 2, is sent to the comparator. When this output signal becomes lower than the reference voltage, the display circuit 12 displays the deterioration of the circuits, particularly the light emitter 2 to the light receiver 3, and whether it is time to replace them.

First, when counting irregularly shaped parts with lead wires, the switch 7 is operated to connect the nonlinear circuit 5 between the input terminal (-) of the comparator 6 and the light receiver 3 as shown in FIG. Switch so that it is inserted. Then, the input signal ei and output signal eo of the conversion amplifier 4 are eo=-R _f-1 as shown in FIG.
The relationship ×f(ei) is established, and exhibits an exponential curve characteristic. The conversion amplifier 4 exhibiting this characteristic is particularly convenient for counting parts having lead wires. In other words, the output signal eo changes greatly due to a slight difference in shape, which results in stable counting. Furthermore, to explain, if parts are inserted between the light emitter 2 and the light receiver 3, the light receiver 3
The amount of light emitted changes and is inputted to the bandpass filter 8 via the conversion amplifier 4. The bandpass filter 8 removes noise caused by external light, etc., and then outputs the counting signal from the bandpass filter 8. The light level compensation comparator 9 outputs a pulse-like count signal after compensating for changes in the characteristics of circuits such as the light emitter 2 and the light receiver 3, and the output circuit 10 receives the count signal and displays the count, or It is printed out and further outputted to control the operation of other devices. For example, suppose that the photoreceiver 3 outputs a signal voltage proportional to the size of the part, and if an input voltage of 10 mV is applied to the conversion amplifier 4 for the element part size of 10 mm ² of the part, From FIG. 4, the output voltage of the conversion amplifier 4 is approximately 4.5V. on the other hand,
Assuming that the foot line of the part is 3 mm ² and that an input voltage of 3 mV is applied to the conversion amplifier 4, the output voltage of the conversion amplifier 4 will be approximately 0.3V from Fig. 4. As a result, compared to the case where the input/output characteristics are directly proportional, the element portion can obtain an output voltage with a larger difference from the lead wire. Therefore, in the case of a part such as a transistor, which consists of an element part and a lead wire made of a wire material with a smaller diameter than the element part, the conversion amplifier 4
, an output that is not proportional to the size of the shape of the part is generated, and the output corresponding to the lead foot line becomes an extremely small value. The signal value of the lead wire output from the conversion amplifier 4 is cut by the optical level compensating comparator 9, and therefore, two or more parts with intertwined lead wires are treated as one part, and especially the intertwined leads. If you also count the foot lines and incorrectly count 3 or more pieces, there is no miscount, so count the appropriate number.
Parts are inserted between the light emitter 2 and the light receiver 3, the amount of light received by the light receiver 3 changes, and the light reception signal output from the light receiver 3 due to this change in the light receiver is processed by a conversion amplifier 4 etc. The output circuit 10 counts and displays the data or prints it out.

When counting parts with minute shapes, operate the switch 7 to connect the nonlinear circuit 5 as shown in FIG.
is inserted between the input terminal (-) and the output terminal of the comparator 6. For this reason,
The conversion amplifier 4 has a relationship between the input signal ei and the output signal eo of eo=f ^-1 (-ei/R _3-1 ), and exhibits a characteristic like a parabolic curve shown in FIG. 6. In the conversion amplifier 4 having the characteristics as shown in FIG. 6, even if the signal voltage input from the light receiver to the conversion amplifier 4 is small because it is a part with a minute shape, the signal voltage input from the conversion amplifier 4 to the conversion amplifier 4 is not proportional to the shape of the part. A signal voltage with an even larger value is output. For example, if the input voltage to the conversion amplifier 4 is 3 mV, the output voltage will be 9V as shown in FIG. Further, if the input voltage to the conversion amplifier 4 is 6 mV, the output voltage increases only by 2V to 11V. In this way, in the conversion amplifier 4 having the characteristics exhibiting the parabolic curve shown in FIG. 6, a large output voltage can be obtained even with a small input voltage, so that counting can be performed without being cut off by the next-stage comparator. It is extremely suitable for counting minute parts.

Note that R _f-1 in FIG. 2 is a resistance, and R _s-1 in FIG. 5 is a resistance.

"Effect of the invention" As described above, according to the counting device using the photoelectric sensor according to the invention, for minute parts, the output signal of the conversion amplifier in response to the light reception signal of the light receiver is converted into a parabolic curve shape. By switching to the characteristics, the value of the output signal does not change much even if the shape differs, and it is converted into a signal that is larger than the shape and processed by a comparator so that it can be counted. Therefore, counting errors do not occur and counting can be performed efficiently. Also, for odd-shaped parts with lead wires, the input/output characteristics of the conversion amplifier are made into an exponential curve, and the signal value of the output of the lead wire from the conversion amplifier to the element part of the part is extremely small, and By performing the cutting process using the reference voltage of the comparator, it is possible to effectively prevent erroneous counting of three or more lead wires, for example, and improve the counting accuracy.

[Brief explanation of the drawing]

The drawings show an embodiment of a counting device using a photoelectric sensor according to the present invention. FIG. 1 is an electrical block diagram of the counting device, FIG. 2 is a circuit diagram of a conversion amplifier when counting irregular objects, and FIG. Figure 3 is the circuit diagram of the nonlinear circuit, Figure 4 is the input/output characteristic diagram of Figure 2, Figure 5 is the circuit diagram of the conversion amplifier when counting minute objects, and Figure 6 is the input/output characteristic diagram of Figure 5. It is. DESCRIPTION OF SYMBOLS 1... Oscillation circuit, 2... Light emitter, 3... Light receiver, 4... Conversion amplifier, 5... Nonlinear circuit, 6...
... Comparator, 7 ... Switch, 8 ... Band pass filter, 9 ... Comparator for optical level compensation, 10 ... Output circuit, 11 ... Light level down comparator, 12 ... Display device.

Claims (1)

[Scope of utility model registration request] In a counting device using a photoelectric sensor that counts the change in light intensity when an object passes between a light emitter and a light receiver by comparing it with a reference level of a comparator,
A conversion amplifier is interposed between the light receiver and the comparator, and the relationship between the output signal and the input signal proportional to the amount of light received by the light receiver can be switched between a parabolic curve and an exponential curve. A counting device using a photoelectric sensor, which is characterized by: