SU891187A1 - Device for detecting marks in strip - Google Patents

Description

each second coincidence circuit is connected to the output of the corresponding inverter, the second input to the direct output of the previous one, counting from the rolling axis, the memory cell, and the output to the recording input of the corresponding memory cell, the reset input of each memory cell is connected to the corresponding photodiode, the inverse output of the memory cells (except the last one) is connected to the first input of the next, counting from the rolling axis, a coincidence circuit, and the direct output of the cells, the memory (except the first one) to the second input of the corresponding coincidence circuit,

Fig. 1 is a functional diagram of a tag detection device in a band on which the levels of logic signals are indicated for the case of a mark indication; 2, the same in the case of interference.

The device contains photodiodes I lane 2, memory cells 3, matching circuit 4, circuit OR 5, second matching circuit 6, and circuit NOT 7.

Photodiodes 1 are located in a line perpendicular to the direction of rolling. The signal from the illuminated photodiode is taken as one, and from the darkened one, is taken as zero.

In the absence of band 2 above the sensor, all photodiodes are illuminated. The memory cells are in the zero state. The code combination 0-1 is fed to the inputs of the matching circuit 4, and a logic zero will be output at the output of the circuit OR 5.

When the band darkens part of the photodiode, a unit is added to the corresponding memory cells 3. The permission to write a unit to the next memory cell when the corresponding photodiode is darkened comes from the previous memory cell, if there is a recorded unit in it, through an additional matching circuit 6. The neighboring cell whose photodiode is lit is in the zero state. The inputs of the coincidence circuit associated with these memory locations will be code combination 0-0. At the inputs of the remaining coincidence circuits, the code combining O - 1. Consequently, the outputs of the coincidence circuits and the OR 5 circuit will be a logical zero.

If any of the darkened photodiodes (except the one adjacent to the illuminated one) lights up when passing over; it has holes corresponding to it

the memory cell returns to the initial state (Fig. 1). The subsequent memory cell does not change its state, since its entries and flush will contain logical zeros. "At the inputs of the match circuit associated with these memory cells, there will be a code pattern of 1-1. Consequently, at its output and at the output of the OR 5 circuit, there will be a PB of the logical unit, which is used as a signal for the presence of a mark in the band.

When an interfering effect, expressed in darkening of one of the illuminated photodiodes, appears, the memory cell corresponding to this photodiode does not change its state, since the recording input of this cell is blocked by an additional matching circuit, the input of which receives a logical zero signal from the direct

0 exits of previous cell

(Fig, 2). The outputs of the matching circuit and the OR 5 circuit store a logical zero.

Claims (1)

1. Photoelectric sensor for indicating holes in a rolled strip. Steel, 1977, No. 7, p. 646.