JPS5876981A - Optical character reader - Google Patents

Abstract

PURPOSE:To extend the life of a lamp, by decreasing a lamp current when an OCR is parted from a paper and does not read, and increasing the lamp current when the OCR is positioned on the paper and the luminous amount of the lamp is less. CONSTITUTION:A light from a lamp 2 connected to a current V is reflected on a paper 1, the reflected light is received at an image sensor 3 to obtain an electric signal (a) corresponding to a character on the paper 1. A comparator 6 compares the signal with zero of the signal (a) to discriminate whether the OCR is positioned on the paper 1 or parted, and if parted, the current of the lamp 2 is decreased. A comparator 7 compares the electric signal (a) with a prescribed value to discriminate whether or not the luminous amount of the lamp is lowered due to aging deterioration, and if lowered, the current of the lamp 2 is increased. Thus, the life of lamp can be extended.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical character reading device 1, which has been improved so that its lifespan is shortened and its reading performance is good over a long period of time.

FIG. 1 is a schematic diagram showing a conventional optical character reading device IT. As shown in Figure 11, the 1 optical character deformation device is used for J! The letter sound optical KWlf is perceived by moving on the El. j! In other words, light emitted from a lamp 2 connected to a power source (indicated by an arrow in the figure) is reflected by a sheet of paper 1, and the reflected light is transmitted from a plurality of photoelectric conversion elements via a lens system (not shown). The light is received by the image sensor 3. Therefore, the image of the character is formed on the surface of the image sensor 30, and a good electrical signal a corresponding to the image of the character is sent from the image sensor 3 to the signal processing path 1 (not shown) via the line 4. Characters are read by these nine signal geography circuits.

In the conventional technology, which takes a lot of effort, once the power supply is turned down, the power is turned off.
4. If the optical character reading device is moving on the paper 1 and reading characters, it will not only move on the paper 1 and read the characters, but also when the optical character reading device is moving away from the paper 1 and is not reading the characters. A constant current was passed through the lamp 2 to obtain the amount of light necessary to read and visualize the characters. This rounding not only shortens the life of the lamp 2, but also has the disadvantage that the optical character reading device overheats, causing discomfort to the operator. Further, when a constant current is passed through the lamp 2, the light amount of the lamp 2 decreases over time due to aging deterioration. Therefore, when an optical character reader is used for a long period of time, its dispersion performance deteriorates.

In view of the above-mentioned prior art, the present invention has a long life and a terminal life K.
l[j)l! An object of the present invention is to provide an optical character reading device with good reading performance. The structure of the present invention that achieves this object is that, when light from a lamp is irradiated onto a sheet of paper on which characters and symbols are written, an image sensor that receives reflected light from the sheet and converts it photoelectrically. Table 1 of this image sensor In an optical character reading device, an electrical signal corresponding to the formed image of the character, symbol, etc. is sent out, and the character, symbol, etc. is read based on this electrical signal. When the optical character reading device is located away from the sheet of paper and the reflected light is hardly received by the image sensor, the electric current flowing through the lamp is reduced, and when the optical character reading device is located on the sheet of paper, the reflected light is hardly received by the image sensor. is received by the image sensor, and when the value of the electric signal becomes smaller than a preset value, control increases the electric current R flowing through the lamp until the reflected light reaches the optimum light intensity for image sensing. It is characterized by being equipped with a circuit.

Embodiments of the present invention will be described in detail below based on the drawings. Note that parts that are the same as those in the prior art are given the same numbers and redundant explanations will be omitted.

Figure 2 is a schematic diagram showing an embodiment of the present invention.

As shown in the figure, this embodiment is equipped with a control circuit connected to the line 4 and the lamp 2. The control circuit 5 comprises comparators 6 and 7, switching means 8 and a lamp driver 9.

To further comment, when the non-inverting input terminal is connected to the line 4 and the comparator 6 is moved away from the paper 1 and the reflected light is hardly received by the image sensor 3, the KEN level becomes L. When the reflected light corresponding to the p1 paper is received by the image sensor 3, a signal bt sound which becomes high level H is sent out. In addition, in the ratio soft 11fr7 whose inverting input terminal is on line 4, the optical character reading device is located above the paper l, reflected light corresponding to the paper is received by the image sensor 3, and the electric signal aO value is the optimum light amount. If the value is larger than the set value, the light level is set to 41 (low level L), which is the optimum light intensity for characters to be clearly seen, and the electric signal -
Even when the O value is smaller than the set value, the signal Cf is sent so that the optimum light amount is reached.

Goo Ha is the comparison -60 output terminal, and the maku input terminal 8b is the comparison 1! ? Connect nine switches to the zero output terminals [8
has the function of transmitting a signal d tone which becomes high level H when both signal S and signal C are high level H. Further, a lamp driver 9 whose input terminal is connected to the output terminal of the switch means 8 and whose output terminal is connected to the power supply via the pipe 2 turns on the lamp 2 when the signal d becomes high level HK.
The current flowing into the lamp driver 9 through the lamp 2 increases, and conversely, when the signal d becomes low level LK, the current flowing into the lamp driver 9 through the lamp 2 decreases. Note that the numbers 10a in the figure represent a bleeder resistor, and 11 represents a buffer amplifier.

Next, the operation of this embodiment will be explained.

(1) When the optical character reading device is located on the paper 1 and the light intensity of the lamp 2 has decreased due to deterioration over time, the value of the electric signal a is equal to the set value of ratio *f) 7] Since the signal C also becomes smaller, the signal C becomes the level H.

Of course, at this time, the signal S is at a high level H. Therefore, when the signal d reaches the level H, the current flowing into the lamp driver 9 becomes large, and as a result, the current flowing through the lamp 27 increases. For this reason, the light quantity of the 2-amp 2 increases until it reaches the optimum setting value, and the 2-amp 2 deteriorates, so that the - character can be read well.

(1) Next, when the optical character reading device moves away from the paper 1 and the reflected light is hardly received by the image sensor i#''3, in other words, when the character is not read, the signal becomes low level L, so the signal C Even if the signal d becomes a high level H, the signal d becomes a low level L. Therefore, no current flows from the rung 2 to the lamp driver 9, and as a result, the current passing through the lamp 2 decreases.

(2) Optical characters 15! When the tortoise device is located on the paper l and the light intensity of the rung 20 is large, the electric signal am value becomes larger than the setting value of the comparison rI7, so the signal C becomes the low level L, and the signal d becomes the low level L9. )
, the current flowing from the lamp 2 to the lamp driver 9KmE decreases until the electric signal a matches the optimum set value. As a result, it is possible to obtain the optimum amount of light for reading characters, and the correct reading quality can be greatly improved.

As specifically explained above in conjunction with the embodiments, according to the present invention, when the optical character reading device separates from the paper and does not scatter the character symbols, K reduces the current flowing through the lamp, and the optical character reading device The device is equipped with a control circuit that increases the current flowing through the rung when the light intensity of the lamp is low (due to aging and deterioration).
This will not only shorten the life of the lamp and prevent the area around the lamp from being overheated, but also improve the WIT removal performance. Incidentally, the lamp life is 500G 1 hour (conventional) to 1 hour.
0000 hours (example to which the present invention is applied), the temperature around the lamp increases from 30°C (conventional) to 20°C (example to which the present invention is applied). The correct reading of the book went from 90X in 1000 hours (conventional) to 99.IIN in 6000 hours (example to which the present invention was applied).

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing a conventional optical character reading device, Figure 2 is a schematic diagram showing a conventional optical character reading device.
FIG. 1 is a schematic diagram showing an embodiment of the present invention. In the drawing, 2 is an IFi paper, 2 is a lamp, 3 is an image sensor, 5 is a tj control circuit, and 4 is an electric signal. Patent applicant: Juchi Denki Kogyo Co., Ltd. Kinshadai, Otori Patent attorney: Shibu Mitsuishi (and 1 other person) Figure 1

Claims (1)

[Claims] Light from the U/P is printed on high-quality paper Kjl on which characters, symbols, etc. are written.
At the same time, the reflected light from this paper is received and photoelectrically converted.
Optical literature Il! An electrical signal compatible with IK is sent out, and characters, symbols, etc. are read based on this electrical signal! In the image sensor, when the optical character reading device is separated from the paper and the reflected light is hardly received by the image sensor, the current flowing through the # marking lamp is reduced and 1
When the optical character reading device is positioned on the sheet of paper and the reflected light is received by an image sensor and the value of the electric signal is smaller than a preset value, the reflected light is detected on the image sensor. A control circuit that increases the electric current #1 flowing through the lamp until the optimum light intensity is reached.
4I optical character reading device.