JPH01303961A - Character reading method on side face of cylinder - Google Patents

Abstract

PURPOSE:To surely read a character string by turning either a cylinder case or a line sensor camera picking up the side face of the case around the center axis of the case and using the line sensor camera to pick up the side face of the case over the entire side face. CONSTITUTION:After an optional position in the circumferential direction of a side face 1b is detected by a line sensor camera 5, a drum 1 is turned around the center shaft 1a by a distance equal to the maximum distance L among adjacent characters 2a, 2a in a detected position S along the circumferential direction of the side face 1b. When the image pickup start position is decided, a line sensor camera 5 picks up the side face 1b of the drum 1 over the entire circumference from the pickup start position while the drum 1 is being turned. Then the video signal of a picture on the side face 1b picked up by the line sensor camera 5 is inputted to a picture processing unit 6, which generates an expanded picture on the side face 1b. Then a character string in the expanded picture is read by a character reader 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a method for reading characters on the side surface of a cylinder, which can accurately read a character string drawn along the circumferential direction on a part of the side surface of a drum can, etc. It is something.

"Prior Art" For example, on the side of a drum filled with radioactive waste, a character string such as a loft number for management purposes is drawn along the circumferential direction of the drum.

Conventionally, this character string has been automatically read by capturing an image of the side surface of the drum with an area sensor camera (two-dimensional camera).

``Problem to be Solved by the Invention'' However, when images are captured using the above-mentioned area sensor camera, the images are affected by the curvature of the side surface of the drum, and in particular, the characters near both ends of the character string are distorted. Characters may become difficult or impossible to distinguish, resulting in a decrease in reading efficiency.Also, special processing is required for characters, such as marking each character to identify the position of a character string. This made automation difficult.

``Object of the Invention'' This invention was made in view of the above circumstances, and it provides a character string on the side surface of a cylindrical container that can reliably read a character string drawn along the circumferential direction on a part of the side surface of a cylindrical container. The purpose is to provide a reading method.

``Means for Solving the Problems'' The method of reading characters on the side surface of a cylinder according to the Kome invention uses a line on the outside of a cylindrical container in which a string of characters along the circumferential direction is drawn on a part of the side surface to image the side surface of the container. Place the sensor camera,
Either one of the line sensor camera and the container is rotated around the central axis of the container, and the line sensor camera detects whether or not the characters or characters are connected within the same distance as the maximum distance between adjacent characters in the circumferential direction. The above character string is detected by detecting a position where no part exists, taking images of the side of the container all around from this position, and applying image processing to the taken images to create a developed image of the side of the container. It is for reading.

"Operation" In the method for reading characters on the side surface of a cylinder according to the present invention, a line sensor camera detects whether characters or We detected a position where a part of the text does not exist, took images of the sides all around from this position, and performed image processing on the captured images to create a developed image of the side. The character string will not be distorted due to the influence of the curvature of the side surface, and the character string will not be divided into two in the middle. Therefore, the character string can be read reliably.

"Embodiment" An embodiment of the method for reading characters on the side surface of a cylinder according to the present invention will be described below with reference to FIGS. 1 to 4.

In these figures, reference numeral 1 indicates a drum (container) filled with radioactive waste. This drum l is rotatably provided around a central axis 11, and its side surface 1b
, a management lot number (character string) 2 consisting of a plurality of characters 21 .

A line sensor camera 5 is installed on the outside of the side surface 1b of the drum l.
is provided. An image processing bag R6 is connected to this line sensor camera 5, and a character reading device 7 is connected to this image processing device 6.

Next, using the line sensor camera 5, the character string 2 is
Explain how to read.

First, the side surface 1 of the drum can 1 is measured by the line sensor camera 5.
The imaging start position of b is determined as follows. That is, after detecting an arbitrary position in the circumferential direction of the side surface 1b by the line sensor camera 5, the drum can l is aligned with the center axis 1&
Around the character 2i, the detected parts S are adjacent to each other,
Side 1 by the same distance as the maximum distance among the distances between 2s
Rotate it so that it moves along the circumferential direction of b.

If part of the character 21 or character 2a is present in the trajectory of the movement of the detected part S, as shown in FIG.
Character 2 in the trajectory of movement of the detected part S by the above maximum distance! Alternatively, the character 21 is rotated until part of it no longer exists, and the part on the side surface lb at this time is set as the imaging start position.

On the other hand, if the character 21 or part of the character 2a does not exist in the locus of movement of the detected region S, as shown in FIG. 3, the end point of this movement is taken as the imaging start position.

Once the imaging start position is determined, the line sensor camera 5 images the entire circumference of the side surface 1b of the drum 1 from the imaging start position while rotating the drum 1.

Next, the side surface 1 imaged by the line sensor camera 5
The video signal of the image b is input to the image processing device 6, and the image processing device 6 creates a developed image of the side surface tb as shown in FIG. Then, the character string in this developed image is read by the character reading device 7.

According to the above method of reading the characters on the side of the cylinder, drum can 1
The side surface 1b of the side surface 1b was imaged by the line sensor camera 5 while rotating the drum l, and this captured image was subjected to image processing to create a developed image of the side surface 1b.The character string 2 in this developed image is the side surface 1b. It is not distorted due to the influence of the curvature. Therefore, character string 2 can be reliably read.

Further, the line sensor camera 5 detects a position where the character 2a or a part of the character 2a does not exist within the same distance as the maximum distance among the distances between the characters 2a adjacent to each other in the circumferential direction of the side surface lb. Since the line sensor camera 5 images the entire circumference of the side surface ib from the lever position, the character string 2 is not imaged from the middle. Therefore, when creating a developed image of the side surface lb, the character string 2 is not divided into two in the middle, so that the character string 2 can be read more reliably.

In the above embodiment, images of the side surfaces 1b of the drum 1 are taken by the line sensor cameras 5 along the entire circumference by rotating the drum 1 around the central axis 1a. This may be done by rotating the line sensor camera 5 around the central axis 11.

"Effects of the Invention" As explained above, according to the method for reading characters on the side surface of a cylinder according to the present invention, either one of a cylindrical container and a line sensor camera that images the side surface of the container is positioned along the central axis of the container. While rotating the container, images were taken of the entire circumference of the container using a line sensor camera, and this image processing was performed to create a developed image of the side surface.The character string in this developed image was It is not distorted by the influence of the curvature of the sides. Therefore, the character string can be read reliably.

In addition, a line sensor camera detects a position where no character or part of a character exists within the same distance as the maximum distance between adjacent characters in the circumferential direction of the side surface, and from this position the entire circumference of the side surface is detected. Since the image was taken over the course of the image, the character string will not be imaged from the middle. Therefore, when creating a side view development image, the character string is not divided into two in the middle, so that the character string can be read more reliably.

[Brief explanation of the drawing]

1 to 4 are for explaining an embodiment of the method for reading characters on the side surface of a cylinder according to the present invention, and FIG. 1 is a schematic diagram showing a state in which the side surface of a drum can is imaged by a line sensor camera. 2 and 3 are schematic diagrams for explaining the method of determining the imaging start position, respectively.
FIG. 4 is a diagram showing a developed image of the side surface of the drum. l...Drum (container), 1a...Center axis, lb...Side, 2...Character string,
21...Character, 5...Line sensor camera.

Claims (1)

[Claims] In a method for reading characters on the side surface of a cylindrical container, which reads a character string consisting of a plurality of characters drawn along the circumferential direction on a part of the side surface of a cylindrical container, a side surface of the container is provided on the outside of the container. A line sensor camera is arranged to image the container, and one of the line sensor camera and the container is rotated around the central axis of the container,
The line sensor camera detects a position where the character or part of the character does not exist within the same distance as the maximum distance between the characters adjacent to each other in the circumferential direction, and from this position the side surface of the container is completely covered. A method for reading characters on a side surface of a cylinder, characterized in that the character string is read by capturing an image around the circumference and performing image processing on the captured image to create a developed image of the side surface of the container.