JPH0230980B2 - TAKASAICHIKENSHUTSUKAIROOYOBIOBIJORENZOKUTAINOMAKITORIMAKIDASHISOCHI - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sample height position detection circuit, and more specifically, the present invention relates to a sample height position detection circuit, and more specifically, when the sample is a deformable continuous strip such as an IC lead frame, The present invention relates to a height position detection circuit that is particularly suitable for use in controlling the height position of a sample between a winding or unwinding device disposed on one side within a safe height range that does not cause deformation.

In recent years, in order to reduce the cost of lead frames for ICs, there has been a tendency to increase the press rotation speed.
In order to produce a wide variety of products, there is a demand for an asynchronous winding and unwinding device for press machines suitable for high-speed winding or unwinding. Therefore, in order to detect the amount of lead frame slack, that is, the height position between the press machine and the winding and unwinding device, and to control the winding and unwinding device, it is possible to reduce the cost and ensure that the lead frame is not damaged. It is desired to develop a detection device that can prevent this.

Conventionally, this type of detection device includes one in which contact switches are provided at upper and lower positions, and one in which a contact roller is used.

In the winding device using the contact switch, as shown in FIG. This will cause slack between it and the take-up reel 3. And this lead frame 2
is wound up on the take-up reel 3 and rises, touches the upper contact switch 5 to stop the drive section 4, and press 1
The paper is sent out from the machine and descends, touches the lower contact switch 6 to activate the drive unit 4, and is wound onto the take-up reel 3.

However, in cases where this contact switch is used, the contact switches 5 and 6 may cause poor contact, or the lead frame 2 may become detached from the contact switches 5 and 6, causing the lead frame 2 to become attached to the take-up reel 3. It may be pulled too much or may accumulate without being wound up. Furthermore, since the drive unit 4 does not continuously control the number of rotations and is controlled ON/OFF, there is also a problem of poor durability.

In addition, as shown in FIG. 2, the contact roller 7 is attached to the lead frame 2.
The speed of the drive section 4 is controlled by detecting the rotation angle of the contact roller 7, which moves up and down together with the lead frame 2, by a detector 8.

In the case of using this contact roller, since the contact roller 7 must be brought into contact with the lead frame 2 by applying a certain amount of downward tension, there is a drawback that the lead frame 2 is easily deformed.

On the other hand, there are devices that shine light or ultrasonic waves onto the surface of the sample and detect the height position of the sample based on the reflection, but those that have an irregular shape and are transported while constantly vibrating like the lead frame mentioned above. In this case, not only the height position but also the slope and shape of the surface change, so the detected amount is not necessarily proportional to the height position of the sample. If this detected amount is simply judged as the height position of the sample and a command is given to the drive unit immediately, the reflection surface will be tilted due to vibration even though the lead frame slack is not that large. When the amount of reflection decreases, a winding command may be issued immediately, which poses a problem that may lead to deformation or breakage of the lead frame.

The present invention was made in view of the above-mentioned problems, and its purpose is to provide a non-contact method for specimens that are not uniformly shaped, without deforming the specimen, and to change not only the height position but also the inclination. To provide a height position detection circuit that can reliably position a sample within a predetermined range even if the sample changes.
The feature is that light waves, sound waves, electromagnetic waves, etc. are irradiated onto the sample surface whose height and slope change over time.
a detector that indicates the amount of displacement of the sample surface and outputs the amount of reflection as an electrical signal; one peak hold circuit that is reset at a predetermined constant cycle and holds the maximum value of the electrical signal between resets; The other peak hold circuit has the same cycle as the one peak hold circuit but is reset at a different time, and holds the maximum value of the electrical signal between resets in the same way as the one peak hold circuit; It consists of a switching means that alternately switches and outputs the outputs of the two peak hold circuits from OFF to ON within the peak hold period, and the height position of the sample is detected by the output of the switching means. It is in.

Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings.

In FIG. 3, the press 1, lead frame 2, take-up reel 3, and drive section 4 are the same as those described in the prior art example.

10 is a detector placed above the lead frame 2.

FIG. 4 shows a height position detection circuit, which is placed above the lead frame 2 as shown in FIG.
A detector 11 that irradiates the lead frame surface with light waves, sound waves, electromagnetic waves, etc. and outputs the amount of reflection indicating the amount of displacement on the lead frame surface as an electrical signal, and a reset circuit that receives the peak wave signal output from the detector. One peak hold circuit 12 and the other peak hold circuit 13 hold the maximum value of the peak wave signal between reset, and the outputs of these two peak hold circuits 12 and 13 are alternately and peak held. OFF in the first half of the period, OFF in the second half
It is comprised of a switching means 14 that switches to ON.

The reference numeral 15 designates a reflective output circuit, which uses the switching means 14 to match and invert the output levels of the peak hold circuit 12 and the other peak hold circuit 13, and a control circuit (not shown) that controls the rotation of the drive section 4. Output to

The output of the detector 11 is maximum when the surface of the lead frame 2 is perpendicular to the detector 11, but the lead frame 2 vibrates because a certain pattern is punched out by the press 1 and is intermittently discharged. Since the angle between the detector 11 and the detector 11 changes constantly, the output of the detector 11 becomes a peak wave signal as shown in FIG. 5a.

The height of each peak wave corresponds to the height position of the lead frame at that time. As the lead frame 2 is wound up on the take-up reel 3 and becomes higher, the slack of the lead frame 2 becomes smaller.
As the distance between the lead frame 2 and the detector 11 becomes smaller, the upper surface of the lead frame becomes nearly horizontal, and the detector 1
The peak value of the peak wave signal of No. 1 becomes large.

However, as the peak value of the peak wave signal increases, the lead frame sag decreases, indicating that the lead frame 2 is approaching the height position where deformation occurs due to excessive tension. A small peak value of the signal indicates that the upper surface of the lead frame 2 is tilted or has a defect due to vibration, and the detected amount may be small, which does not necessarily indicate that the lead frame 2 has a large amount of slack. isn't it.

Therefore, for example, immediately winding up the lead frame 2 to reduce the slack after receiving a peak wave signal with a small peak value may deform or cut the lead frame 2 or damage the press die. There is a risk of

Therefore, when the slack of the lead frame is decreasing, that is, when the peak value of the peak wave signal is increasing, a signal with a level corresponding to this peak wave signal is outputted to the drive unit 4. When the slack of the lead frame 2 is increasing, that is, when the peak value of the peak wave signal is decreasing, a time lag is provided to respond to the peak wave signal. It is necessary to output a level signal and use this output to control the slack of the lead frame 2. Such an output is obtained by alternately taking out the outputs of the one peak hold circuit 12 and the other peak hold circuit 13.

That is, the one peak hold circuit 12
is an OP amplifier 16 which is input to the non-inverting input terminal of the detector 11 and the output of the peak hold circuit 12 is input to the inverting input terminal, and a capacitor to which the output voltage of this OP amplifier 16 is charged via a diode 17. 18, the terminal voltage of this capacitor 18 is applied to the gate, and the FET 20 whose source is grounded via the resistor 19, the inverting input terminal and output terminal of the OP amplifier 16, and both terminals of the capacitor 18 are simultaneously shot. switch 21
The source of the FET 20 becomes the output of the peak hold circuit 12.

Then, the switch 21 is turned on at a period of 2T as shown in FIG. 5b, and the peak hold circuit 12 is reset.

The other peak hold circuit 13 is also constructed in the same manner as the one peak hold circuit 12, and its reset switch 22 has a period of 2T and a reset period of the switch 21, as shown in FIG. 5c. It is turned ON midway between the ON and ON periods, and the peak hold circuit 13 is reset.

Therefore, both peak hold circuits 12,1
3, the maximum value of the peak wave signal of the detector 11 is sequentially held overlapping every half cycle T.

As shown in FIG. 5d, the output of the peak hold circuit 12 is turned OFF when the switch 21 is turned ON, and is turned ON when the switch 22 is turned ON. Output to. Also, peak hold circuit 1
The output of 3 is ON or ON when the output of the peak hold circuit 12 is OFF, as shown in Figure 5e.
It is output by the switch 24 which turns off when it is on.

In the peak hold circuit 12, switch 2
The maximum value of the peak wave signal of the detector 11 while the switch 23 is OFF is output while the switch 23 is ON, and the maximum value of the peak wave signal of the detector 11 while the switch 23 is ON is higher than the maximum value of the peak wave signal during the OFF period. When a large peak wave signal is input, the maximum value corresponding to the peak wave signal will be output. On the other hand, switch 2
Even if a peak wave signal smaller than the maximum value of the OFF period is input during the ON period of 3, the output does not change, but the maximum value of the peak wave signal during this period is held in the peak hold circuit 13. It is output when the switch 24 is turned on.

Fig. 5g shows an output example of the peak hold circuit 12 (the output between the arrows), Fig. 5h shows an output example of the peak hold circuit 13, and the inverting output circuit 1 at this time shows an output example of the peak hold circuit 13.
The input to 5 is as shown in FIG.

The drive section 4 is controlled according to the input to the inverting output circuit 15. As is clear from the above, in this embodiment, the peak hold circuit 1
2, if the maximum value held during the first half period T is output during the second half period T, and there is a peak wave signal larger than the first half maximum value during this second half period T, then will be output with this larger signal value. Peak hold circuit 13
But it's the same. In other words, in this embodiment, the drive unit 4 is controlled based on the maximum peak wave signal in each cycle so as not to overwind the lead frame. Even if there is a small peak wave signal during this period, it is ignored unless this peak wave signal manifests as a maximum value during the period T. That is, even if there is a small peak wave signal, a signal to immediately wind up the lead frame is not issued, a predetermined time flag is obtained, and malfunctions due to vibration of the lead frame are prevented.

Note that the period T is longer than the time it takes for one pattern of the lead frame 2 to pass, and during this time T, one or more peak wave signals having a peak approximately proportional to the amount of slack in the lead frame are obtained. Make it. When the press 1 is operated at high speed, excellent responsiveness can be achieved by setting the time T short according to the rotation speed of the press 1.

The drive unit 4 is controlled in proportion to the output signal of the inverting output circuit 15 or through a circuit that further winds this output signal and sets the unwinding speed, thereby maintaining the slack of the lead frame 2 within a certain range. It will be done.

In addition, in the case of lead frame 2, the direction in which the slack increases is the safe side, so when lead frame 2 is moving in the direction in which the slack increases as described above, this can be detected with excellent responsiveness. However, if the direction in which the slack decreases is on the safe side, the output of the detector 11 is inverted and input to the peak hold circuits 12 and 13. Alternatively, the detector 11 may be installed below the lead frame 2.

In this way, according to the present invention, since a non-contact type sensor is used, the height position can be detected without deforming even a sample that is easily deformed, such as a lead frame. Even when the sample is vibrating, the two peak hold circuits are overlapped and alternately switched to output the sample, so the sample height can be maintained within a certain safe range without causing deformation. Moreover, since the sample height control section such as the winding speed of the take-up reel can be controlled continuously or semi-continuously, the drive section can be made highly durable and safe. This has significant effects such as controllability.

Although the present invention has been variously explained above with reference to preferred embodiments, the present invention is not limited to these embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. It is.

[Brief explanation of drawings]

1 and 2 are explanatory diagrams using a conventional height position detector, FIG. 3 is an explanatory diagram using a height position detection circuit according to the present invention, and FIG. 4 is an explanatory diagram using a height position detecting circuit according to the present invention. An example of a position detection circuit, FIG. 5 is a time chart and an input/output waveform diagram. 1...Press, 2...Lead frame, 3...
Take-up reel, 4... Drive unit, 5, 6... Contact switch, 7... Contact roller, 8, 10, 11... Detector, 12, 13... Peak hold circuit, 14
...Switching means, 15...Inversion output circuit, 16...
OP amplifier, 17...Diode, 18...Capacitor, 19...Resistor, 20...FET, 21,
22, 23, 24...switch.

Claims (1)

[Claims] 1. A detector that irradiates a sample surface whose height and inclination change with time with light waves, sound waves, electromagnetic waves, etc. and outputs the amount of reflection indicating the amount of displacement of the sample surface as an electrical signal; One peak hold circuit is reset at a constant cycle and sequentially holds the maximum value of the electric signal between resets; Similar to the peak hold circuit shown in FIG. a height position detection circuit that detects the height position of a sample based on the output of the switching means; 2. A drive unit is provided that rotates a reel around which a continuous band-shaped body such as a lead frame is wound to wind up or unwind the continuous band-shaped body, and is provided with a drive unit that faces the surface of the continuous band-shaped body extending outward from the reel. placed,
A detector is provided that irradiates the surface with light waves, sound waves, electromagnetic waves, etc. and outputs the amount of reflection indicating the amount of displacement of the strip-shaped continuous body as an electrical signal. One peak hold circuit sequentially holds the maximum value of the electrical signal, and the other peak hold circuit has the same period but is reset at different times, and like the one peak hold circuit, there is a the other peak hold circuit that sequentially holds the maximum value of the electrical signal at the peak hold period; and switching means that alternately switches and outputs the outputs of the two peak hold circuits from OFF to ON within the peak hold period. a continuous belt-shaped body, comprising: a height position detection circuit, and a control unit that controls the drive unit according to the output of the height-position detection circuit so that the continuous belt body is at a predetermined height position. Winding and unwinding device.