JPS5929500A - Lead center position detecting system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is particularly applicable to component inserters and the like.
The present invention relates to a lead center position detection method for detecting lead center positions of electronic components having a diverse number of electronic components (for example, so-called odd-shaped components, in which each component has a different lead shape).

First, the conventional method will be explained according to the drawings.

FIG. 1 is a system configuration diagram of an example of a conventional lead position detection method, and FIG. 2 is a detection waveform diagram thereof.

First, when the lead L moving in the direction of the arrow blocks the irradiation beam light from the projector 1, the output of the light receiver 2 becomes zero.

The position of the lead L at this time can be read by an encoder 5 that is synchronized with its movement.

The output current I of the light receiver 2 is converted into a voltage by a current-voltage conversion circuit 3, and an output voltage V as shown in FIG. 2(a) is obtained. This output voltage V and the threshold voltage VTR are compared in the comparator circuit 4, and only during the period when the output voltage V exceeds the threshold voltage VTR, the comparator circuit 4 outputs a position detection pulse P as shown in FIG. is output.

By inputting this pulse P to the clock terminal CK of the register 7, the read position Detection output can be obtained.

However, with this conventional method, as shown in Figure 2 (A), for components with a relatively large lead width, the position detection pulse (■) is not processed even if there is a delay due to the rise and fall portions of the output voltage V. Although it is detected with a slight deviation from the waveform change width W corresponding to the lead width, as shown in Figure 2 (b), for components with small lead widths, the output voltage ■ is equal to the threshold voltage "v'T1". (If the lead width does not reach VTR, there is a risk of detection being impossible, and it cannot be used to detect the lead position when the lead width changes.) This means that even if the lead width changes, the threshold voltage VTR This is because it cannot be made to change correspondingly.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lead center position detection method that eliminates the above-mentioned drawbacks of the prior art and is capable of accurately detecting the center position of leads of various widths.

The structure of the lead center position detection system according to the present invention is such that the irradiation beam light is blocked by a lead moving in a predetermined direction at a predetermined speed, and after converting the piece/light amount into a corresponding voltage, A lead width pulse corresponding to the lead width is generated by comparing the threshold voltage specified and generated by the voltage with the converted voltage, and its leading and trailing edges are synchronized with the movement of the lead. Each count data of the encoder output is obtained and the average value thereof is outputted as the lead center position data.

In short, by specifying the threshold voltage for position detection pulse generation in advance according to the lead width,
By reliably generating a position detection pulse and detecting each edge before and after the pulse, an attempt is made to detect the midpoint as the lead center position.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 3 is a system configuration diagram of an embodiment of the lead center position detection method according to the present invention, FIG. 4 is a detection waveform diagram thereof, and FIG. 5 is a flowchart of the same.

Here, 1 is a light emitter, 2 is a light receiver, 3 is a current-voltage conversion circuit, 4 is a comparison circuit, 5 is an encoder, and 6 is
Counters 7A and 7B are registers, and 8 is an ODA conversion circuit for specifying a threshold voltage, 9A.

9B is an edge detection circuit for the leading edge and trailing edge, and 1o is an average value circuit. Note that among these symbols, the same ones as those in FIG. 1 are equivalent.

First, when the lead L moving at a predetermined speed in the direction of the arrow blocks the irradiated beam light from the projector 1, the output current 2 of the light receiver 2 becomes positive, indicating the passage of the lead. This output current is input to the current-voltage conversion circuit 3 and is converted into a voltage V corresponding to the amount of received beam light (step 1 in Fig. 5).
1.12).

On the other hand, since the threshold value designation signal is input as a digital signal from the outside to the J)A conversion circuit 8, this is DA converted by the same circuit and outputted as the threshold voltage vTl+ (
Same step 13.14).

In addition, the encoder 5 outputs a pulse with a frequency proportional to the moving speed of the lead L (step 15), and by integrating this pulse with the counter 6 (step 16), the position of the lead L can be determined. You can ask for it.

Next, the output voltage V converted by the current-voltage conversion circuit 3 is
The comparator circuit 4 compares it with the threshold voltage VTR, and outputs a lead width pulse P (referred to as a position detection pulse in the conventional example described above) corresponding to the width of the lead L passing through the irradiation beam light. (Same step 17). This pulse P is
As shown in FIG. 4, a portion of the output voltage V that is lower than the threshold voltage VT)I is output. That is, the pulse width of this lead width pulse P represents the width of the lead L. Here, the threshold voltage VT)I that determines the pulse width of the lead width pulse P can be arbitrarily set to a desired value from the outside, so even if the width of the lead L is narrow, the threshold voltage VTl + can be supplied.

Next, the edge detection circuits 9A and 9B detect the lead width pulse ■
], the leading edge and trailing edge of the lily pulse P corresponding to both ends of the lead L are detected, and each detection pulse F and Rk are outputted (step 18).

The positions of the leading edge and trailing edge detection pulses F and 几 are determined by the counter 6.
It can be found from the output of In other words, the register A represents the position of the stage 7 when the leading edge detection pulse is input by the cumulative number of encoder 5 outputs (thus, the value of the counter 6 at that time is represented by the leading edge 7, :(i2j data Similarly, for the trailing edge, output 7'stuff1.
Trailing edge position data B is output from step 3 (step 19).
).

Finally, the center position data of the lead L is obtained by calculating the average value (A+B)/2 of the leading edge position data A and the trailing edge 1 standing data B in the average value circuit 1o (step 20).

In this way, since the center position of the lead is determined after both edges of the lead are rendered, correct position detection can be performed even for leads of various different widths. By changing the V value to a predetermined value according to the lead width, it is possible to detect the position of a narrow lead, which was not worn out in the conventional method, and improve performance. I can do it.

As explained above in detail 1], according to the present invention, it is possible to accurately and reliably roast the center position of leads of various widths, thereby improving the reliability of processes such as parts insertion. , remarkable effects on efficiency improvement and economy can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a system configuration diagram of an example of a conventional lead position detection method, Fig. 2 is a detection waveform diagram thereof, Fig. 3 is a lead center position detection method according to the present invention, and Fig. 4 is its detection. The waveform diagram and FIG. 5 are the same flowchart. ■...Emitter, 2...Receiver, 3...Current-voltage conversion circuit, 4...Comparison circuit, 5...Encoder, 6...
...Counter, 7A, 7B...Register, 8...D
A conversion circuit, 9A. 9B: Edge detection circuit, 10: Average value circuit. Agent: Patent attorney Kosaku Fukuda (and one other person)

Claims (1)

[Claims] 1. The irradiation beam light is blocked by a lead moving at a predetermined speed in a predetermined direction, and the amount of the beam light is converted into a corresponding voltage, and then the threshold voltage specified and generated in advance according to the width of the lead and the above conversion are performed. A lead width pulse corresponding to the lead width is generated by comparing the voltage with the lead width, and each count data of the encoder output that is synchronized with the movement of the lead is obtained for the front and trailing edges, and the average value is calculated. A lead center position detection method that outputs the lead center position data.