SU953642A1 - Photoreading device - Google Patents

Description

(S) PHOTO-READING DEVICE

one

The invention relates to computing, automation, telegraphy and. intended for use in data input devices, data transmission and communications equipment.

Devices for reading information from a perfume carrier are known, where the luminous flux from an inclined light source hits the information carrier. In the absence of perforations on the tape, the luminous flux is reflected from the tape and through the light guides falls on the photodetectors of the reflected flux. In places where there are information holes, the stream passes through them and falls on the photodetectors of the forward channel {Г.

A disadvantage of this device is the great complexity of the design and insufficient overall weight characteristics.

A device is known that uses a series of photocells included in a bridge circuit with a single power source, in which one coaxial photodetector 2 is connected to obtain a given signal-to-noise ratio.

The disadvantage of it is the mutual influence of the working photodetectors included in the diagonal of the bridge on each other.

ten

The closest to the image of the technical essence is a device that uses a light source, a series of photodetectors, a counter, a shift register, a synchronization unit, and AND 3- elements.

A disadvantage of the known device is the need for accurate balancing of the entire circuit, especially when exposed to destabilizing factors:

Claims (3)

20 ambient temperature, the variation of the parameters of the device components, the change in supply voltages and others. This reduces the reliability of devices. The aim of the invention is to increase the reliability of the device. This goal is achieved by the fact that a device containing a light source, optically coupled through the carrier with workers and directly with the reference photoreceivers, a counter, a shift register, a synchronization unit and an And element, has a switch, a decoder, a comparison unit, and the outputs working photodetectors are connected to the information inputs of the switch, the output is connected to the first input of the comparison unit, the second input of which is connected to the output of the reference photoreceiver, and the output of the comparison unit is connected to the information The shift input of the shift register, the bits of the counter are connected to the control inputs of the switch and to the inputs of the decoder, the output of which is connected to the first input of the And element and to the input of the synchronization unit, the other input of which is connected to the read bus and is the first input of the device and the output of the block synchronization is connected to the sync bus and. is the first output of the device, the second input of the AND element; the clock input of the counter is connected to the clock bus and is the second input of the device, and the output of the AND element is connected to the clock input of the shift register whose output is connected by the code bus which is the second output of the device . Such a construction of the device makes it possible to significantly increase the reliability of operation by eliminating the mutual influence of working photodetectors using a switch. The readout information from the punched tape through the working photodetectors is sequentially compared with the reference one, and then transformed into a parallel code using the shift register. This allows an individual comparison of the signals from the working and reference photodetectors and simple means to compensate for the measurement of the supply voltage and the ambient temperature. FIG. 1 shows a block diagram of the device; in fig. 2 shows a time diagram of the device operation when reading a five-element combination 01101. Light source 1 is optically connected through working medium 2 to working photodetectors 3 and directly to reference photodetector C. The outputs of working photoreceivers 3 are connected to informational 5 inputs of switch 6 and its output is connected to the input 7 of the block 8 comparison. Its other input 9 is connected to the output of the reference photodetector k. The output of the comparison unit 8 is connected to the information input 10 of the shift register 11, the bit outputs of which are connected to the code bus 12. The bit outputs of the counter 13 are connected to the control inputs C of the switch 6 and the inputs of the decoder 15, the output of which is 17 and the input of the synchronization unit 18. The output of the synchronization unit 18 is connected to the synchronization bus 19, which is the first output of the devices, and its control input is connected to the read bus 20, which is the first input of the device. The clock bus 21, which is the second input of the device, is connected to the clock input of the counter 13 and the input 22 of the element 17, the output of which is connected to the clock input 23 of the shift register 11. The operation of the device is as follows. When a radiant device is turned on, the energy of the light source 1, falling on the working photodetectors 3 through the perforating medium 2, .to the reference photodetector k enters directly. Under the influence of clock pulses, post. On the busbar 21, the counter 13 continuously operates and switches the switch 6. At the same time, the signals of the working photodetectors 3 are successively fed to the output of the switch 6 and further to the input 7 of the comparison unit 8. The other input 9 receives the signal of the reference photodetector. The result of the comparison is fed to the information input 10 of the shift register 11 and is recorded in its first bit. The information is written to the shift register 11 and advanced along the bits of the register is influenced by clock pulses from element I 17. At the same time, using signals the decoder 15, from the continuous clock sequence 5 at the input 22 are formed at the output of the element And 17 a series of clock pulses controlling the recording and shifting of information in the register 11 of the chip. At the first time moment (the state of the counter 00000), the first working photodetector 3 is connected to the comparison unit 8 and the comparison unit 8 registers the read O, which is written to the first digit of the shift register 11. The switch then connects the second working photodetector 3, the comparison unit 8 registers 1, which is recorded in the first register bit 11, and the first read O moves in the second bit. Further work proceeds similarly and all five working photodetectors are polled for five clock pulses 3 and the information from them is sequentially located in the shift register 11. Then, the decoder 15 triggers a signal that prohibits the passage of clock pulses through AND 17 (and hence the change of information in shift register 11) and enters synchronization block 18, which, when a read signal arrives on bus 20, generates a sync signal. This signal arrives at the signal synchronization bus 19 and witnesses the arrival of the read information on the code bus 12. Used in the proposed device, the double conversion of the read code combination allows an individual comparison of the signals of each working photoreceiver with the reference signal and, with the identity of the working and reference photoreceivers, achieve a significant increase in the reliability of reading information under the conditions of various destabilizing factors in the supply voltage, ambient temperature environment, etc. The advantage of the device is the possibility of transition to a pulse and alternate on cheniyu ialuchateley (usually with a total of 42 the number of .fotopriemnikov), which will reduce power consumption. A photoreading device comprising a light source optically coupled through a perforating medium to workers directly with a reference photoreceiver, a counter, a shift register, a synchronization unit, and an element AND, in order to increase the reliability of the device, a switch, a decoder are inserted into it , a comparison unit, and the outputs of the working photodetectors are connected to the information inputs of the switch, the output of which is connected to the first input of the comparison unit, the second input of which is connected to the output the reference photoreceiver, and the output of the comparison unit is connected to the information input of the shift register, the outputs of the counter bits are connected to the control inputs of the switch and to the inputs of the decoder, the output of which is connected to the first input of the And element and to the input of the synchronization unit whose other input is connected to the read bus and is the first input of the device, and the output of the synchronization unit is connected to the synchronization bus and is the first output of the device, the second input of the AND element and the clock input of the counter are connected to the clock This is the second input of the device, and the output of the element I is connected to the clock input of the shift register, the output of which is connected to the code bus, which is the second output of the device. Sources of information taken into account in the examination 1. USSR author's certificate number 378901, cl. G About K 7/1, 1970. 2. USSR author's certificate (f 357557 /, cl. G 06 K 7/1, 19b9. 3. USSR author's certificate №, cl. G About K 7 / U, 1977 (prototype). Ssi S t3 M M "M C & / us YU N “0