JPH07200730A - Character reader and character label - Google Patents

Abstract

PURPOSE:To exactly recognize a character in a short period by easily &i finding the central position and inclination of each character. CONSTITUTION:When the image data of a character label 3 attached onto the upper face of an article W are found by a CCD camera 2, those data are binarized by a binarizing part 11, and the positions of a start mark and a stop mark in the fixed position relation to both the ends of the character string of the character label 3 on that image are found by a pattern matching part 13. Based on these positions, the inclination and center deviation of each character can be found by a a pattern matching part 13. Based on reference pattern data correcting part 15, and inclination/center deviation corrected reference pattern data can be found. A character matching part 18 fetches image data near the center of the character from an image memory 12 and matches those data with the inclination / center deviation corrected reference pattern data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a character reading device and a character label for picking up an image of a character and performing matching, and is particularly applied to a case where the position and inclination of the character to be read with respect to the character reading device are not constant. Character reading device and character label.

[0002]

2. Description of the Related Art In a distribution center, a branch of a case on a conveyor is judged, and a bar code label attached to an article is read by a bar code reader to discriminate an object.

[0003]

The bar code label is attached to the upper surface or the side surface of the case, but it is difficult to attach the bar code label at a certain accurate position and orientation.
Further, the position and orientation of the conveyed article itself are also different. Therefore, it is desirable to have a bar code reader that can accurately read the bar code regardless of where and in what direction it is attached. However, such a bar code reader has a complicated structure and is quite expensive.
If the characters are read by the character reading system instead of the barcode, it is possible to deal with the position and inclination of the character with respect to the imaging device, but it takes a long time to correct the position and inclination, and it is necessary to recognize the character in a short time. It could not be applied to the transport system etc.

Therefore, it is an object of the present invention to read characters of an image attached to an article such that the information can be read accurately and in a short time even if the position and orientation of the information with respect to the reading device are different. To provide a reader and a character label.

[0005]

In order to achieve the above object, the invention according to claim 1 has a constant relative positional relationship with both ends of a character string in which two or more characters are continuous at a constant interval. Character reading that recognizes the start and end positions of the character string by identifying the start mark and the stop mark, calculates the position and inclination of each character that composes the character string from the start and end positions, and performs matching Configured the device.

The invention according to claim 2 has a character string in which two or more characters are continuous at a constant interval and is provided at a constant relative position with respect to both ends of the character string, and has mutually different predetermined configurations. A character label was constructed with a start mark and a stop mark.

[0007]

Since the present invention has the above-mentioned structure, it has the following effects.

According to the character reading device of the first aspect of the invention, the character reading device distinguishes the start mark and the stop mark from the imaged image data. Since the start mark and the stop mark have a fixed relative positional relationship with both ends of a continuous character string of two or more characters, the positions of the start end and the end of the character string can be recognized. Since the characters forming the character string are at regular intervals, the character reading device can obtain the center position and inclination of each character by calculation, and perform matching after performing the corresponding processing.

According to the character label of the second aspect of the present invention, the start mark and the stop mark having different predetermined configurations are fixed at both ends of a character string in which two or more characters are continuous at a constant interval. Since the character reading device recognizes the positions of both ends of the character string by identifying the start mark and the stop mark, the character reading device can obtain the center position and inclination of each character.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments shown in the drawings will be described below.

FIG. 1 is a functional block diagram showing the configuration of an embodiment of a character reading apparatus according to the present invention, and this embodiment is used for determining a branch of a conveyor.

In FIG. 1, the character reading device 1 is a CCD.
Image data captured by the camera 2 is input to read characters. The CCD camera 2 images the upper surface of the article W conveyed on a conveyor (not shown),
The character string written on the character label 3 attached to the upper surface is read. The conveyor controller 4 receives the result of the character string recognition from the character reading device, the product type determination unit 5 determines the product type, and the branch determination unit 6 performs the branch determination based on the result, and the pass sensor adjacent to the conveyor is used. The drive device is controlled at the timing when the article passage detection signal is received.

FIG. 2 is a plan view showing an embodiment of the character label 3 according to the present invention. The character label 3 is issued by a barcode labeler (not shown) and is attached to the article W by an adhesive applied to the back surface. On the upper surface of the character label 3,
Start mark 31, stop mark 32, character string 3
3. The barcode 34 is printed by the barcode labeler.

Start mark 31 and stop mark 3
Both 2 have a circle shape but different sizes. For example, the start mark 31 has a black line with an outer diameter of 10 mm, an inner diameter of 6 mm, and a line thickness of 2 mm.
Is. The stop mark 32 has a black line with an outer diameter of 6 mm, an inner diameter of 2 mm, and a line thickness of 2 mm. The reason why the start mark 31 and the stop mark 32 have a circle shape is that pattern matching is easy if the character shape of the character label 3 is inclined with respect to the CCD camera 2 as long as it has a circle shape.

Start mark 31 and stop mark 32
A character string 33 is written between and. Character string 33
The left end of the character string is at a fixed position with respect to the position of the start mark 31, and the right end of the character string 33 is at a fixed position with respect to the position of the stop mark 32. Therefore, if the positions of the start mark 31 and the stop mark 32 are known, the position of the character string 33 can be known, and since the characters are lined up at regular intervals, the center of each character can be known. The bar code 34 has the same content as each character of the character string 33, and is used for reading data by a bar code reader for other purposes. The font of each character is of a fixed type.

In order to cope with the conveyor speed of 1 m / sec, the image data imaged by the CCD camera 2 three times per second at a shutter speed of 1/3000 is binarized by the binarization unit 11 to obtain an image. In addition to being stored in the memory 12, the pattern is transferred to the pattern matching unit 13, and the start mark 31 and the stop mark 32 are pattern-matched to recognize their positions on the image. Since this pattern matching is easy, it is processed into hardware and processed at the video rate (1/30 seconds).

The character position calculator 14 uses the start mark 3
From the positions of 1 and the stop mark 32, the inclination and center shift of the character string 33 are calculated and sent to the reference pattern correction unit 15. The reference pattern correction unit 15 reads the reference pattern data from the reference pattern data unit 16 and corrects the read reference pattern data based on the inclination and the center deviation to obtain inclination center deviation corrected reference pattern data 17. The reference pattern correction unit 15 uses hardware capable of parallel processing so that the reference pattern data of all registered characters can be processed simultaneously.

The character matching unit 18 obtains the center position of each character from the character position calculation unit 14 and extracts the image data near the center of each character (for example, 9 × 9 pixels) from the image memory 12. This is performed in parallel while the reference pattern correction unit 15 corrects the inclination. The retrieved image data is
Character matching is performed with the inclination center deviation correction reference pattern data 17, and each character is recognized. The time from imaging to obtaining the character recognition result is about 1/3 second.

The character matching is a pixel-by-pixel comparison, but if the reference pattern data in the reference pattern data section 16 has a resolution in pixel units, it will be considerably out of alignment when correcting the inclination and center deviation. Virtually has reference pattern data with a resolution that is five times as high as or more than that of a pixel, and performs inclination and center deviation correction on the reference pattern data, and then aggregates the light and dark data in pixel units to form a tilt and center deviation correction reference pattern I am trying.

As described above, according to the character reading device 1 of the present embodiment, the recognition of the characters described in the character label 3 is
It can be performed in a short time regardless of the deviation of the center position of the character with respect to the CCD camera 2 and the inclination.

The embodiment of the present invention has been described above.
It is needless to say that the present invention is not limited to the above-mentioned embodiments and can be appropriately modified within the scope of the gist of the present invention.

For example, although only numbers are shown in the character labels in the illustrated embodiment, other characters such as alphabets, katakana, hiragana, kanji, and symbols such as mathematical symbols can also be read. .

[0023]

As described above, according to the character reading device of the first aspect of the present invention, the character reading device can easily obtain the center position and inclination of each character, so that the character recognition can be shortened. It can be done in time.

According to the character label of the second aspect of the present invention, the center position and inclination of each character forming the character string can be easily known, and therefore the time required for character recognition can be shortened. .

[Brief description of drawings]

FIG. 1 is a functional block diagram showing a configuration of an embodiment of a character reading device according to the present invention.

FIG. 2 is a plan view showing an example of a character label according to the present invention.

[Explanation of symbols]

 1 Character reading device 11 Binarization unit 12 Image memory 13 Pattern matching unit 14 Character position calculation unit 15 Reference pattern correction unit 18 Character matching unit 2 CCD camera 3 Character label W Article

Claims (2)

[Claims] 1. A start mark and a stop mark, which have a constant relative positional relationship to both ends of a character string in which two or more characters are continuous at a constant interval, are identified to recognize the start and end positions of the character string. Then, the character reading device is characterized in that the position and the inclination of each character forming the character string are calculated from the positions of the start end and the end to perform matching. 2. A character string in which two or more characters are continuous at regular intervals, and a start mark and a stop mark which are provided at fixed relative positions with respect to both ends of the character string and have mutually different predetermined configurations. A character label characterized by having.