JPS6129080Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is based on patterns of characters, symbols, etc. written on boxes, cards, bags, etc., or patterns of characters, symbols, etc. written on labels affixed to boxes, cards, bags, etc. The present invention relates to a pattern reading device that optically reads patterns of marks affixed to boxes, cards, bags, etc.

Various types of pattern reading devices are known, and they are designed to read diffusely reflected light, and are used, for example, to automatically read and recognize postal codes written on the front of postcards, envelopes, etc. It has been put into practical use. However, the patterns that can be read by conventional postal code reading devices are limited.
For example, if a white bag has a window covered with transparent cellophane, film, vinyl, etc., and the ground color inside the window is white, there is no difference in contrast and the envelope cannot be read. In other words, for an envelope with such a window, it is necessary to first read the position and orientation of the window, and then read the pattern inside the window, but since there is no difference in contrast between the bag and the inside of the window, it is necessary to detect the diffuse reflected light. It is not possible to read the position or orientation of the window. Also, when detecting a label or mark attached to a box, card, etc., if the background color of the box or card is the same as the background color of the label or mark, reading will be difficult. Can not.

The purpose of the present invention is to accurately read patterns of objects for which there is no difference in contrast by detecting diffusely reflected light, and to create patterns that can also be detected using diffusely reflected light. The purpose is to provide a reading device.

The pattern reading device of the present invention includes a means for illuminating an object where the gloss of an area where a pattern such as a character or symbol to be read is recorded is different from the gloss of other areas, and a position for receiving diffuse reflected light from the object. A pattern is created by processing the video signal supplied from the diffuse reflection light receiving means arranged, the specular reflection light receiving means arranged at a position to receive the specular reflection light from the subject, and the specular reflection light receiving means. It is characterized by comprising a reading circuit that detects a recorded area and then processes a video signal supplied from a diffuse reflection light receiving means that receives diffuse reflection light from the detected area to read a pattern. It is something to do.

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

FIG. 1 shows an example of a windowed envelope suitable for being read by the pattern reading device of the present invention. The main body 1A of the envelope 1 is made of, for example, white paper, and a window 1B is pasted with transparent cellophane, through which the contents 2 placed in the envelope 1 can be seen. The other color is also white like the main body 1A. Such windowed envelopes are widely put into practical use. In this case, the addressee is written on the content 2, which is read through the window 1B. However, when reading the postal code 3 written on such an envelope, it is necessary to first check the window 1B and then read the postal code inside the window. The reason for this is that, for example, if the envelope body 1A contains characters or symbols 4, they may be mistaken for a postal code. However, it has not been possible to accurately confirm the window 1B using conventional reading devices. The reason for this is that although the conventional reading device detects diffusely reflected light, the background color of the contents 2 seen through the main body 1A and the window 1B are both white, and there is no difference in contrast.

Therefore, in the present invention, as shown in FIG. 2, not only diffusely reflected light is detected, but also specularly reflected light is detected. In the example shown in FIG. 2, for example, a flying spot scanner 10 for one-dimensional scanning is provided, and a light spot formed on the screen surface is transmitted through an optical system consisting of a mirror 11 and a lens 12 to an object, in this example a window. envelope 1
irradiate. A first photomultiplier tube 13 is placed at a position to receive diffusely reflected light from the subject 1, and a second photomultiplier tube 14 is placed at a position to receive specularly reflected light. The output video signals of these photomultiplier tubes 13 and 14 are supplied to a reading circuit 15. The reading circuit 15 is provided with a switch 16 for selectively passing both video signals, a reading determination section 17, and a control section 18 for controlling the operating modes of the switch and the reading determination section.

FIG. 3A shows the waveform of the output video signal of the first photomultiplier tube 13 which receives the diffusely reflected light. This video signal is obtained when the flying spot scanner 10 scans the envelope 1 shown in FIG. 1 along the arrow a--a. As described above, the main body 1A of the envelope 1 and the background color of the contents 2 visible through the window 1B are the same, so the main body 1A and the window 1B cannot be distinguished. On the other hand, the signal obtained when character 3 of content 2 is scanned is relatively large. On the other hand, as shown in FIG. 3B, the output video signal of the second photomultiplier tube 14 that receives specularly reflected light is determined by scanning the window 1B and the signal level obtained by scanning the main body 1A of the envelope 1. The resulting signal level will be significantly different. The reason for this is that the gloss of the paper constituting the envelope body 1A is significantly different from the gloss of the cellophane covering the window 1B. Therefore, by processing the video signal supplied from the second photomultiplier tube 14 that receives such specularly reflected light, the position and orientation of the window 1A can be confirmed very accurately. . On the other hand, in the video signal supplied from this second photomultiplier tube 14, the signal component representing the character portion 3 is small.

As is clear from the above explanation, when reading the character section 3 through the window 1B of the windowed envelope 1, first the control section 18 turns on the switch 1.
6 is driven to the state shown in the drawing, and a video signal supplied from the second photomultiplier tube 14 that receives specularly reflected light is supplied to the reading determination section 17. Reading determination section 1
7, the position and orientation of the window 1B can be determined using the threshold level shown by the broken line S in FIG. 3B. Once the window 1B has been detected in this way, the switch 16 is switched to the opposite state from that shown in the drawing, and the output video signal from the first photomultiplier tube 13 that receives the diffusely reflected light is read. The information is supplied to the determination unit 17. The reading determination unit 17 reads the character portion 3 using the threshold level indicated by the broken line P in FIG. 3A. In this way, the character portion 3 written on the contents 2 of the envelope 1 can be read accurately.

In the present invention, as described above, the first photomultiplier tube 13 that receives diffusely reflected light and the second photomultiplier tube 14 that receives specularly reflected light are provided. Various modes can be considered for how to process the video signal. For example, normally the diffuse reflection light channel is activated, and when the contrast decreases, the specular reflection light channel is selectively activated, or both channels are constantly activated and the reading judgment section selects the channel. , it is possible to keep both channels in constant operation and process both signals together to read the pattern. Furthermore, in the case of detecting labels or marks affixed to cards with the same ground color but different gloss, it is sufficient to activate only the channel of specular reflection light.

The present invention is not limited to the above-mentioned example, but can be modified and changed in many ways. For example, in the above example, a one-dimensional flying spot scanner is used, but a two-dimensional flying spot scanner may also be used. Furthermore, various light receiving devices other than photomultiplier tubes can also be used. Furthermore, a television camera can be used instead of a flying spot scanner.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a windowed envelope suitable for being read by the reading device of the present invention, FIG. 2 is a block diagram showing the configuration of an example of the pattern reading device of the present invention, and FIGS. 3A and B is a signal waveform diagram similarly explaining the operation. 1...Envelope with window, 1B...Window, 10...Flying spot scanner, 13, 14...Photomultiplier tube, 15...Reading circuit, 16...Switch,
17...Reading determination unit, 18...Control unit.

Claims (1)

[Scope of utility model registration request] A means for illuminating an object in which an area in which a pattern of characters, symbols, etc. to be read is recorded has a gloss different from that in other areas, and a diffuse reflection light receiving means arranged at a position to receive the diffuse reflection light from the object. and a specular reflection light receiving means disposed at a position to receive specularly reflected light from the subject, and detecting an area where a pattern is recorded by processing a video signal supplied from the specular reflection light receiving means. A pattern reading device further comprising: a reading circuit that reads a pattern by processing a video signal supplied from a diffuse reflection light receiving means that receives the diffuse reflection light from the detected area.