SU743018A1 - Information readout device - Google Patents

Description

one

The invention relates to automation and information technology and can be used to read data from tape media, for example, from magnetic tape or film.

A device for reading information is known, comprising a perceptual unit, pulse generators connected via gates and averaging units to the comparison unit 1.

The closest technical solution to the invention is a device comprising a sensing unit connected via a first phase detector to a first integrator, a second integrator, and a clock pulse generator 2.

A disadvantage of this device is the possibility of distortion of information when the speed of movement of the carrier changes and the information and clock signals are out of sync and, most importantly, the reliability of the device is insufficient.

The purpose of the invention is to increase the reliability of a device for reading information.

This is achieved by the fact that the known information reading device comprises a second phase detector, first and second threshold elements, shift registers and elements AND, a comparison unit and an OR element, the first integrator through the first threshold element connected in series, the first shift register and the first element connected to one of the inputs of the OR element, the sensing unit through the second phase detector connected in series, the second integrator, the second threshold element, the second shift register and the second element NT And is connected to another input of the OR element, the first input of the clock pulse generator is connected to the output of the sensing unit, its second input is connected to the output of the comparator block and to the first and second And elements, the first output of the clock generator is connected to the first and second phase detectors and clock inputs of the first and second shift registers, and the inputs of the comparison unit are connected to the first and second threshold elements.

FIG. 1 shows a functional diagram of the device for reading information; in fig. 2 - time diagram of his work.

The device contains a sensing unit 1, a generator of 2 clock pulses, the first and second phase detectors 3 and 4, made synchronized, the first and second integrators 5 and 6, the first and second threshold elements 7 and 8, the comparison unit 9, the first and second shift registers 10 and 11, the first and second elements AND 12, 13 and the element OR 14. The sensing unit 1 through successively connected first and second phase detectors 3 and 4, integrators 5 and b, threshold elements 7 and 8, shift registers 10 and 11 and elements And 12 and 13 are connected to the element OR 14. The generator 2 clock the pulses are connected to the perceptual unit G, the AND 12, 13 elements and the comparison unit 9 connected to the threshold elements 7 and 8, in addition, the 2 clock pulse generator is connected to the first phase detector 3 and the shift register 10 input and to the second phase detector 4 and clock input shift register P.

The device for recording information works as follows.

When reading out information signals from a carrier (Fig. 2a) with relative phase shift, signals are generated at the output of perceptual unit 1 (Fig. 26) arriving at the inputs of the first and second phase detectors 3 and 4, which detect these signals in accordance with clock frequencies coming to their second inputs from the generator outputs 2 clock signals, and the clock signals are shifted in phase by 180 ° relative to each other (Fig. 2c, c).

Further, these signals (Fig. 2d, d) are integrated by integrators 5 and 6 Schfig. 2d, d) and arrive at threshold elements 7 and 8, where three signal levels are distinguished: zero, positive and negative, and, depending on the level of the signal, the logical zero or one goes to the inputs of the shift registers 10 and 11. In this case, if the information from the carrier is read correctly, i.e., if this information is correctly clocked by pulses from the generator 2 clock pulses, then the signals "failure - pulses from the output of the threshold element 7 to the first input of the comparison unit 9" will not be received. At the same time, from the output of the threshold element 8 to the second input of the comparison unit 9, pulses will arrive, because the information pulses on this channel are clocked incorrectly, with a shift of 180 °. Therefore, at the output of the comparator unit 9, the signal "1" arrives at the generator of 2 clock pulses, i.e., the clock clocks are correctly attached to the fronts of the information signals from the output of the receiver unit 1. The same signal "1 from the output of the comparison block 9 is fed to the input

element 12, this permits the passage of information from the output of the shift register 10 through the element 12 and the element OR 14 to the output of the device, to the consumer of information.

If the "fail" pulses start to come from the output of the threshold element to the first input of the comparison unit 9, and from the output of the threshold element 8, the pulses "fail to the second input of the comparison block 9, then the output signal of the comparator appears on the output of the comparator 9 clock pulses are now adjusted to the fronts of information signals from the output of perceptual unit 1, shifted by 180 ° relative to the previous sequence. The signal "O from the output of the comparison block 9 permits the passage of information from the output of the shift register 11 through the AND 13 element and the OR 14 element to the device output.

The technical and economic effect of the invention is to increase the reliability of the information read from the media.

Claims (2)

1. US patent number 3949394, cl. 340-34TD; published in 1976. 2. USSR author's certificate number 458018, cl. G 11 B 5/02, 04/26/73.  i