JPS5962986A - Optical information reader - Google Patents

Abstract

PURPOSE:To read optical information stably, by switching light emission of illumination light of plural color to control a color illumination light proper to a drop-out color. CONSTITUTION:On the surface of a read data label 1, a mark printed in the drop-out color is arranged in a specific position, and a frame is constituted with partitions of the drip-out color, and various numbers are printed in an ordinary ink in this frame. High-luminance LEDs 2a, 2b, and 2c are allowed to emit light independently of one another, and the output signal of a two-dimensional read sensor 5 is subjected to analog amplification in an analog amplifier 6 and has the wavefor shaped by a waveform shaping circuit 7 and is subjected to A/D conversion in an A/D converter 8 and is sent to a microcomputer 9. The output of this computer 9 is given to an illumination control circuit 12, and a light source 2 is controlled by the output of the circuit 12. The LED having the color by which the white background part of the label and the mark part of the drop-out color have the least level difference is lit to read characters of the label 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical information reading device that reads optical information such as characters and codes recorded on an information medium.

Conventionally, this type of device prints characters, symbols, etc. on the label within a frame separated by a dropout color.
The reading device processes only the optical information signals within the frame, but depending on the color of the illumination light, the effect of the dropout color may not be effective and the Ut reading process may be incorrect. may occur. As a countermeasure to this, a filter that cuts out the light of the dropout color is placed in front of the reading sensor, and in this case, a visible light cut filter is often used as a countermeasure for the dropout color in a wide wavelength range. However, there are problems in that the filter limits the types of colors printed on the label and causes the adverse effects of sensitivity non-uniformity (bleeding) that is specific to a reading sensor using a silicon-based semiconductor light-receiving element.

The present invention has been made in view of the above-mentioned problems, and it is possible to appropriately select and control the color of illumination light using a light emitting means that generates illumination light of a plurality of colors, thereby eliminating the need for a special filter and eliminating dropout. The purpose is to eliminate the negative effects of color.

To this end, in the present invention, illumination light of a plurality of colors is sequentially switched and generated by the light emitting means, and when each of the illumination lights is illuminated, the light-to-electrical conversion means is turned on and off corresponding to an image of a predetermined mark of the dropout color on the information medium. The apparatus includes command means for determining illumination light of a color having a high reflectance based on the signal and issuing a selection command thereafter, and applies the selection command to a control means for switching and controlling the light emitting means.

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

FIG. 1 is an overall configuration diagram showing an embodiment of the optical information reading device of the present invention. 1 is a read data label of an information medium, and as shown in FIG. 2, optical information is written in a certain format. has been written. 2 is a light source that illuminates the read data label. This light source includes a plurality of blue, green, and red high-intensity light emitting diodes 2a, 2b, and 2c that are in specific wavelength ranges, and constitutes a light emitting means. High brightness light emitting diodes 2s, 2b, 2c of each color are scattered so that the front surface of the read data label 1 is uniformly illuminated with the illumination light of the high brightness light emitting diodes 2a, 2b, 2c of each color, and a scattering material is placed on the front surface. is inserted.

The light emitted from this light source 2 illuminates the read data label l, and this illumination light is reflected light with a different light intensity distribution due to different reflectance according to the character string of the read data label 1. can get. This reflected light is reflected by the lens 3. An image is formed through the aperture member 4 onto the surface of the two-dimensional reading sensor 5 of the light-to-electrical conversion means. This two-dimensional reading sensor 5 converts an image on the surface into an electrical signal by a 1U child scanning operation. The dash-dotted line in FIG. 1 shows the trajectory of light in the optical system. Reference numeral 11 denotes an image sensor driving circuit which generates a lock necessary for driving the two-dimensional reading sensor 5 by changing the clocks of various clock generation circuits 10 and applies it to the reading sensor 5.

Reference numeral 6 denotes an analog amplifier that amplifies the electrical signal obtained by the scanning operation of the two-dimensional reading sensor 5. A waveform shaping circuit 7 shapes the waveform of the electrical signal obtained from the analog amplifier 6, and is composed of a sample bold circuit that converts it into a continuous signal and a low-pass filter that smooths the output waveform. This waveform-shaped electrical signal is converted to A-D.
Through conversion circuits 11 & 8, the signal is changed into a signal that can be taken into the microcomputer 9. When the output of the A/D conversion circuit 8 is input to the microcomputer 9, based on this information, arithmetic processing according to a predetermined program is executed to read characters. 10 is various clock generation circuits, sample bold and A' in the waveform shaping circuit 7;
The reference clock for -D conversion is necessary for driving the two-dimensional reading sensor 5, and the lock timing is created.

Reference numeral 12 denotes a lighting control circuit, which is designed to independently light up high-intensity light emitting diodes of each color based on a signal from the microcomputer 9.

FIG. 3 shows a detailed electrical wiring diagram of the lighting control circuit (2). In other words, when the red light emitting diode is turned on, the microcomputer 9 applies a LOW signal to the R terminal.

Similarly, if you want to turn on the green light, add a LOW signal to the G terminal, and if you want to turn on the blue light, add a LOW signal to the B terminal.

On the surface of the read data label 1 that is illuminated by the illumination light of each color, a predetermined mark la printed in a dropout color is placed at a specific position as shown in FIG. Within the frame, various numbers 1c are printed using normal ink.

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

Currently, the microcomputer 9 is selecting the color of the illumination light by the arithmetic processing shown in the 1-chart of Fig. m5.

First, high brightness light emitting diodes 2a+2b of each color.

2c are turned on separately, and the output signal of the two-dimensional reading sensor 5 is sent to the analog amplifier 6. Waveform shaping cycle [187, A
- The data is taken into the microcomputer 9 through the D conversion circuit 8. And Drosopout Karano prescribed mark 1a
Look at the information on the part. At this time, since the dropout mark Ia is printed on a predetermined portion, it is sufficient to process only the signal corresponding to the specific portion.

Then, from the information of this specific part, it can be seen that the high-brightness light emitting diode of the color that has the smallest level difference between the white background part of read data label 1 and the mark part of the dropout color is the least susceptible to the influence of the dropout color. . Therefore, a color that is less affected by this dropout color is compared and determined, and the +Tl1lIli light emitting diode of that color is turned on to perform a reading operation and read the characters on the read data label 1. In this way, reading can be performed with little influence from the dropout color, resulting in improved performance.

In other words, selecting a color with a small level difference between the video signal corresponding to the predetermined mark la portion of the dropout color and the signal corresponding to the surrounding white background portion is, in other words, 1. In this case, the conjunctive light of the color whose reflectance with respect to the illumination light of a specific color is as high as that of the white background part will be selected, and this will cause dropout as data processing to be exposed to the signal from the two-dimensional reading sensor 5. Color separation #
Data processing of signals only within the frame of fA1b can be efficiently executed.

FIG. 4 shows high-brightness light emitting diodes 2a of each color.

This is an example showing the wavelength characteristics of 2b and 2c, the reflectance characteristics of various dropout colors, and the reflectance characteristics of various types of printing. 13 is the wavelength characteristic of the red light emitting diode 2c, I4
is the wavelength characteristic of the green light emitting diode 2b, 15 is the wavelength characteristic of the blue light emitting diode 2a, I6 is the reflectance characteristic of the red dropout color, 17 is the reflectance characteristic of the green dropout color, and 18 is the reflectance of the blue dropout color. Characteristics 19 is the reflectance characteristic when printed with a thermal printer, and 20 is the reflectance characteristic of a black ballpoint pen. From this figure, it can be seen that the reflectance of various dropout colors is not affected well in the infrared region, but
For printing, black ballpoint pen, thermal printer [1]
The reflectance of printed materials rapidly increases in the infrared region, making them difficult to read.In particular, the reflectance of printed materials with a thermal printer rapidly increases from about 650 nm.

For this reason, in the infrared region, which is not affected much by various dot-out colors, there are restrictions on printed matter, and in the infrared region, the sensitivity of silicon-based image sensors is non-uniform. (bleeding). From this, it can be seen that in order to perform stable reading without being restricted by printed matter, it is better to use each visible light region that is less affected by dropout colors. Therefore, in order to read without being influenced by several types of dropout colors, several types of light sources having spectra in specific wave ranges corresponding to the reflectance characteristics of the individual dropout colors are required. For this purpose, various spectra (n, green, red) of small and highly reliable high-brightness light emitting diodes 2a, 2b, and 2C are used.
By combining a plurality of light sources and using them as a light source, it is possible to read printed matter without limitations.

In the above-described embodiment, the high-brightness light emitting diode to be lit is selectively controlled based on the information at the predetermined mark 1a of the dropout color on the read data label 1, but the predetermined mark la of the dropout color Information about the light emitting diode of the color that should be lit may be indicated in advance with a signal. For example, if a red dropout color is used, press "R" to light the red light emitting diode. Also, those that light up a green light emitting diode are printed with "G", and those that light up a blue light emitting diode are printed with "rBJ". In this case, it should also be shown in a designated location and no dropout collars should be used around it. Then, character recognition is performed for the symbol part, and based on the results, a red light-emitting diode is turned on for "1G", a green light-emitting diode is turned on for "1G", and a blue light-emitting diode is turned on for rBJ.
All you have to do is go into mouth reading mode.

Furthermore, by blinking light emitting diodes of various colors, an error message or completion of reading can be notified.

As described above, according to the present invention, it is possible to selectively control the illumination light of an appropriate color for the drombed out color by exposing the signal processing when sequentially switching and controlling the illumination light of a plurality of colors by the light emitting means. This has an excellent effect in that it is possible to remove the adverse effects of multiple types of drop-out and drop-out colors without using a special filter, and to read stable optical information.

[Brief explanation of drawings]

Figure 1 is an overall configuration diagram showing one embodiment of the present invention, Figure 2 is an explanatory diagram of the label, Figure 3 is a detailed electrical wiring diagram of the lighting control circuit in Figure 1, and Figure m4 is an explanation of the operation. The reflection characteristic diagram provided, Figure ff15, is a flowchart of the main part of the microcomputer in Figure 1. l... Read data label of information medium, 2... Light source of light emitting means, 3, 4... Lens of optical system, aperture member, 5
...Two-dimensional reading sensor serving as optical-to-electrical conversion means, 9.
...Microcomputer serving as command means, 12...
A lighting control circuit that serves as a control means. Figure 2 Figure 1b Figure 3 Figure 4

Claims (1)

[Scope of Claims] A light emitting device that generates illumination light of each color in a plurality of specific wavelength ranges, a control device that independently switches and generates illumination light of each color of the light emitting device, and a predetermined mark of a dropout color. an optical system that illuminates an information medium carrying optical information with the illumination light and forms an image reflected from the illumination light at a predetermined position; an optical-to-electric conversion means that converts the image into an electrical signal; and illumination of each of the colors. The lights are sequentially switched and generated, and the illumination light of a color with a high reflectance is determined based on the signal corresponding to the predetermined mark in the electric signal caused by each illumination light, and the control means is thereafter driven based on the determination. and command means for selectively commanding illumination light of that color.