JPS641829B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical information reading device that optically reads information optically recorded on a recording medium using an electronic scanning type reading sensor.

[Conventional technology]

Conventional devices of this type illuminate optically recorded information, form an image of the information obtained by this illumination on a reading sensor, and convert the electrical signal obtained by the photoelectric conversion function of this reading sensor. There is something that reads the above information.

However, in conventional devices, it has been difficult to reduce power consumption due to the power required for lighting. Furthermore, in order to reduce the power required for illumination, a device has been proposed in which illumination is performed only when information is at a predetermined reading position, and the information is read using this illumination.

However, in such conventional devices, the illumination must be started and the reading sensor must start the reading operation when the information arrives at the reading position, and it is necessary to accurately position the information at the reading position. When the positioning was not performed accurately, the reading rate decreased.

[Problem to be solved by the invention]

In view of the above-mentioned problems, the present invention makes it possible to achieve accurate and high reading rates by improving the reading control of the reading sensor without relying on the positioning of optically recorded information, and moreover, by improving the reading control of the reading sensor, An object of the present invention is to provide an optical information reading device that can achieve an accurate and high reading rate while reducing power consumption.

[Means to solve the problem]

In order to achieve the above object, the present invention includes: illumination means for illuminating optically recorded information in response to an illumination command; and a plurality of photoelectric conversion elements that transmit images of the information illuminated by the illumination means. reading means for converting the electrical signals into electrical signals by converting them into electrical signals and sequentially outputting the electrical signals of the plurality of photoelectric conversion elements during a reading period that starts in response to a reading command; a timing control means for repeatedly generating the illumination command in synchronization with the generation cycle of the reading command; A technical means is adopted in which the system is equipped with a signal processing means that repeatedly reads recorded information.

[Action and effect]

According to such an optical information reading device of the present invention, the reading means and the illumination means are periodically and repeatedly given reading commands and illumination commands by the timing control means. Then, the signal processing means periodically and repeatedly reads the information based on the electrical signal that is periodically and repeatedly output from the reading means.

As described above, according to the optical information reading device of the present invention, since optically recorded information is read periodically and repeatedly, an accurate and high reading rate can be obtained, and the illumination by the illumination means can improve the reading of the reading means. Since this is performed periodically in synchronization with the , low power consumption can be achieved. Furthermore, since both the reading means and the illumination means are operated periodically and repeatedly, the timing control means only needs to periodically generate these reading commands and illumination commands, and it is necessary to accurately synchronize them with information positioning, etc. Therefore, an accurate and high reading rate can be achieved with a simple configuration.

〔Example〕

The present invention will be explained below with reference to embodiments shown in the drawings.

In Fig. 1, numeral 1 is a light transmitting section, which transmits the irradiated light from the flashing discharge tube 1A, which emits light by instantaneously discharging the charge stored in the capacitor, toward the object to be read, and 1B is a light transmitting section. This is a circuit that drives the flashing discharge tube 1A.

2 is a light receiving section that receives reflected light from the object based on the irradiation light of the light transmitting section 1, and 2a is a MOS type image forming a charge accumulation type reading sensor in which a plurality of photoelectric conversion elements are continuously arranged on a reading line. The sensor 2b is a lens that adjusts and focuses the image of the reflected light onto a predetermined range on the reading line of the image sensor 2a, and 2c is an aperture adjuster that adjusts the amount of light collected by the lens 2b.

The image sensor 2a receives a clock pulse of a constant frequency, and its plurality of photoelectric conversion elements cyclically repeat a linear scanning type reading operation to sequentially convert images on the reading line into electrical signals.

3 is a card serving as a recording medium, on the surface of which is printed and recorded barcode information in which barcodes are grouped in a linear arrangement of wide and narrow bar symbols 3a, and in the line direction of the bar symbols 3a. The image sensor 2a is provided with a reflected light signal from a black and white line at a linear reading position 3b substantially orthogonal to the image sensor 2a, and moves on the reading surface in the direction of an arrow 3c that coincides with the line direction of the bar symbol 3a. .

Reference numeral 4 denotes an analog circuit section that amplifies a weak video signal generated by the cyclic reading operation of a plurality of photoelectric conversion elements of the image sensor 2a and converts it into an intermittent signal;
6 is a data converter that converts the intermittent signal generated by the analog circuit 4 into a parallel digital signal corresponding to the bar code based on the clock pulse; 6 is a microcomputer that applies a synchronizing signal to the data converter 5 to convert the parallel digital signal; It reads the signal, executes its confirmation process, and then executes various arithmetic processes.

Reference numeral 7 indicates a timing control means that generates a clock pulse of a constant frequency and supplies it to the image sensor 2a, the flash drive circuit 1B, and the data converter 5, and also generates another synchronous clock pulse and supplies it to the microcomputer 6. This is the clock generator.

8 is a card feeding device, which moves the card 3 by arrow 3.
It automatically moves along the c direction,
It is composed of a motor, a belt, a pair of rollers, etc., and the card 3 is inserted between the rollers to feed the card. Control means for reading the barcode information by cyclically repeating the reading operation of a plurality of photoelectric conversion elements in the image sensor 2a while the barcode information is being moved from those denoted by reference numerals 4 to 6. It consists of

FIG. 2 is a detailed configuration diagram of the light transmitting section 1.
1b is a DC-DC converter that boosts the power supply voltage to a high voltage, 1c is a capacitor for storing high voltage, 1d is a flashing start circuit having a thyristor, and 1e is a flashing stop circuit.

Then, the capacitor 1c is charged with a high voltage from the DC-DC converter 1b, and upon receiving the flashing start pulse 7a from the reference clock generator 7, the high voltage charge in the capacitor 1c is discharged into the flashing discharge tube 1A. It generates a flashing light, and then receives a flashing stop pulse 7b from the reference clock generator 7 to stop the flashing.

FIG. 3 is a detailed configuration diagram of the reference clock generating section 7, where 7c is a clock generator that generates clock pulses of a constant frequency, and 7d is a clock generator that counts and performs logical operations on the clock pulses to generate a flashing start pulse and a flashing stop pulse. 7e is a delay circuit that delays the flash stop pulse 7b; 7f is an R-S flip-flop; 7g
is an AND gate, R-S flip-flop 7f
The passage of the clock pulse is interrupted by the output signal of the clock pulse.

Then, the clock pulse from the clock generator 7c is supplied to the microcomputer 6, and the flashing start pulse 7a and flashing stop pulse 7b from the timing control circuit 7d are supplied to the flashing driving circuit 1B.
In addition, the read clock pulse that has passed through the AND gate 7g is applied to the image sensor 2a and the data converter 5.

Next, the operation of the above configuration will be explained.

Now, when the card 3 moves on the reading surface in the direction of the arrow 3c shown and reaches the reading position 3d, a card detector (not shown) detects that the card has arrived and starts reading the barcode information.

At this time, the flashing discharge tube 1A responds to the timing of the flashing start pulse (FIG. 4c) and flashing stop pulse (FIG. 4d) from the reference clock generator 7 as shown in FIG. 4a. Instantaneous (e.g. 0.5m
sec) discharge and flash irradiation, and reading scanning is started after a delay time d (0.5 msec to 1 msec) shown in FIG. 4b. And the flashing discharge tube 1A
The barcode surface of the card 3 is illuminated by the flash of light emitted by the discharge of
Reflected light signals with different reflectances from the black and white bar symbols on the straight line b pass through the lens 2b, form an image on the image sensor 2a, and are temporarily stored in the image sensor 2a. At this time, if the amount of light reaching the image sensor 2a is too large, it is adjusted by the aperture adjuster 2b. Similarly, one reading scan of the image sensor 2a is completed, and before the next reading scan, the flashing discharge tube 1A is caused to discharge and emit light, and the next reading scan is performed. That is, the flashing discharge tube 1A is repeatedly discharged in synchronization with the reading scan of the image sensor 2a. Therefore, the image sensor 2a irradiated with the reflected light signal generates a weak analog electrical signal proportional to the light energy. This analog electrical signal is amplified and waveform shaped in the analog circuit section 4.
The signal is converted into an intermittent signal by an A/D conversion circuit, and for example, a white line code signal is converted to a 1 level signal, and a black line code signal is converted to a 0 level signal. This intermittent signal is determined in the data converter 5 as either a wide bar signal or a narrow bar signal,
The information code of the determined barcode is then converted into a binary code. Then, the converted ternary code is read into the microcomputer 6 by a synchronization signal from the microcomputer 6, and output to various peripheral devices (not shown).

In addition, the noise generated during the discharge of the flash discharge tube 1A affects the image of the image sensor 2a,
To avoid this, after the discharge of the flash discharge tube 1A, the scanning of the image sensor 2a is delayed by the delay circuit 7e until the noise is reduced to ensure a reading operation with fewer malfunctions. I can do it.

As mentioned above, since the flashlight from the flashlight discharge tube 1A is used to illuminate the barcode surface of the card 3, the lighting equipment can be downsized.
Moreover, the illumination energy can be reduced compared to continuous illumination, and the brightness of the illumination light can be easily increased, making it possible to perform highly accurate reading.

In the above embodiment, the card 3 is moved, but a manual reading method in which the light receiving section 2 is moved may also be used.

Further, although a bar code is shown as the code information, other codes may be used as long as they are optically readable.

In addition, although a MOS type is illustrated as an example of the image sensor 2a, if it is a charge accumulation type, a CCD
Other image sensors, such as those of the (charge coupled device) type, may also be used.

Furthermore, although the flash stop pulse shortens the flash discharge time, when the flash interval is long, the flash stop pulse is unnecessary and the flash is emitted for the discharge time of the capacitor 1c. In this case, the circuit configuration for controlling the timing of light irradiation can be simplified.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention;
Fig. 2 is a detailed block diagram of the light transmitting section, Fig. 3 is a detailed block diagram of the reference clock generating section, and Fig. 4 is a, b, c,
d is a time chart used to explain the operation of the present invention. 1...Light transmitting section, 1A...Flashing discharge tube, 1B...
...Flash light drive circuit, 2... Light receiving section, 2a... Image sensor forming a reading sensor, 3... Card recording barcode of code information, 4... Analog circuit section, 5... Data conversion section, 6 . . . Microcomputer, 7 . . . Reference clock generating section serving as timing control means.

Claims (1)

[Scope of Claims] 1. Illumination means for illuminating optically recorded information in response to an illumination command; and converting an image of the information illuminated by the illumination means into an electrical signal by a plurality of photoelectric conversion elements. a reading means for sequentially outputting electrical signals of the plurality of photoelectric conversion elements during a reading period that starts in response to a reading command; and a reading means that repeatedly generates the reading command at a predetermined period longer than the reading period. , timing control means for generating the illumination command in synchronization with the generation cycle of the reading command, and processing the electrical signals of the plurality of photoelectric conversion elements output for each reading command, and processing the electrical signals of the plurality of photoelectric conversion elements outputted for each reading command, 1. An optical information reading device comprising: signal processing means for repeatedly reading information.