JPH0676101A - Character reading device - Google Patents

Abstract

PURPOSE:To provide a character reading device which can surely read the characters written on the end face of an object with no influence of the disturbance light and the dust. CONSTITUTION:An image sensor 1 is provided at a position opposite to an end face 2a of a steel stock 2 to read the characters 3 written on the face 2a. Then an illumination device 5 is added to illuminate the face 2a together with a luminous intensity sensor 4 set at a position close to the face 2a respectively. The image signal received from the sensor 1 and the luminous intensity detection signal received from the sensor 4 are inputted to a signal processor 6. Then the illumination output of the device 5 is controlled by the processor 6. In such a way, the luminous intensity equivalent to the end face of an object is directly detected and therefore the luminous intensity can be detected with no influence of the disturbance light and the dust. Then the characters can be surely read with the proper luminous intensity controlled based on the luminous intensity detection signal.

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 for reading a character written on an end face of an object by a character reading image sensor.

[0002]

2. Description of the Related Art Conventionally, there are various character reading devices for reading characters and the like written on paper such as facsimiles and OCRs. With these devices, it is not necessary to consider the influence of ambient light or dust on the character reading surface, and the environment in which the device is installed is relatively good.

By the way, characters such as an identification number may be written on the surface of steel materials such as slabs, blooms, and thick plates handled in the field of iron and steel in order to confirm differences in materials. Since the character reading device for reading the characters written on these steel materials is sometimes used outdoors due to the steel process, it is easily affected by dust and differences in ambient light due to changes in day and night. In order to reduce these effects, it is conceivable to provide a lighting device to make the character reading surface bright.

For example, Japanese Patent Application Laid-Open No. 61-49552 discloses a method of correcting deterioration and temperature dependence of the light source itself, which is controlled based on the illuminance of the light source alone. No consideration is given to any effect between the light source and the character reading surface. In addition, JP-A-61-1
Japanese Patent Laid-Open No. 58373 and Japanese Patent Laid-Open No. 61-58374 disclose that the illuminance of a read image is measured by a light-receiving sensor to control the illumination. Since a complicated mechanism for switching is also required, there is a problem that the cost of the device increases. Further, Japanese Laid-Open Patent Publication No. 1-155478 discloses that the illuminance measurement is performed by using a reference reflection plate. In this case, however, the circuit is complicated such that the same image sensor processes reflected light. However, it is limited to a one-dimensional image sensor and its application is likely to be limited.

[0005]

SUMMARY OF THE INVENTION In view of the problems of the prior art, the main object of the present invention is to ensure that the characters written on the end face of the object are not affected by the influence of ambient light or dust. An object of the present invention is to provide an improved character reading device for reliable reading.

[0006]

According to the present invention, there is provided a character reading device for reading a character written on an end face of an object, which is provided facing the end face of the object. Image sensor for reading characters, an illuminating device for illuminating the end face of the object, an illuminance sensor installed in the vicinity of the end face of the object, and an illumination output of the illuminating device based on a detection value of the illuminance sensor. It is achieved by providing a character reading device characterized by having a control device for increasing / decreasing.

[0007]

With this configuration, even if the illuminance of the character reading surface of the object changes due to the influence of ambient light or dust, the changed illuminance can be detected by the illuminance sensor, and the illuminance at that time can be detected. By controlling the output of the lighting device, the character reading surface can be illuminated so that the illuminance is such that the character can be read.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view showing the entire character reading device to which the present invention is applied. The steel material 2 that is the object of character reading may be appropriately conveyed on, for example, a conveyor (not shown), and may be conveyed outdoors, for example, during the conveyance. On the end surface 2a of the steel material 2, for example, a row of characters 3 for indicating a product number or the like is marked or marked with an ink jet, and the characters 3 are displayed by the image sensor 1 of the present invention during the outdoor transportation. Read.

The image sensor 1 is, for example, a television camera having a function of automatic focusing and automatic zooming. The lens is attached to the end surface 2a of the steel material 2 placed at the reading position.
, So that they face each other with a certain distance,
The image sensor 1 is installed via a mount (not shown). Note that the image sensor 1 may be installed, for example, so as to be movable vertically and horizontally depending on the position of the steel material 2.

An illuminance sensor 4 fixed via a bracket (not shown) is arranged near the end surface 2a of the steel material 2 at the reading position. In addition, the end surface 2a of the steel material 2
In order to irradiate the light, an illumination device 5 made of, for example, a fluorescent lamp is arranged in the vicinity thereof. The image signal from the image sensor 1 and the illuminance detection signal from the illuminance sensor 4 are electrically connected so as to be input to the signal processing device 6, respectively. Then, both are electrically connected so that the irradiation output of the lighting device 5 is controlled to be increased or decreased by the signal processing device 6.

In the character reading apparatus constructed as described above, when the position sensor (not shown) detects that the steel material 2 is placed at the reading position, the illuminance detection value detected by the illuminance sensor 4 is signal-processed. Captured in the device 6. At this time, for example, when a certain amount of irradiation is performed in advance by the illumination device 5, the illuminance due to the irradiation light and external light is detected.

When there is air fluctuation, dust, or water vapor between the end surface 2a of the steel material 2 and the lighting device 5, or when it becomes cloudy or at night, the end surface 2a has an illuminance necessary for character reading. When the illuminance is not reached, the illuminance sensor 4 can detect the lack of illuminance. In that case, the illuminance control signal is output from the signal processing device 6 to the illuminating device 5 in order to increase the illuminance output of the illuminating device 5 in accordance with the detected illuminance value so that the illuminance becomes the specified value. Further, when the external light is strong, the irradiation output of the illumination device 5 may be lowered or controlled to be further stopped.

As described above, since the end surface 2a of the steel material 2 is illuminated with the illuminance suitable for reading, the character written on the end surface 2a can be easily and surely read by the image sensor 1. Then, the signal processing device 6 outputs a character reading signal to an image processing device (not shown), and the image processing device interprets the character.

[0015]

As described above, according to the present invention, since the illuminance sensor is installed in the vicinity of the end face on which the characters of the object are marked, it is possible to detect the illuminance by the external light as well as the light emitted by the illuminating device. Therefore, the illuminance on the character reading surface can be detected almost accurately. Then, when the illuminance is insufficient due to the influence of dust or the difference of the ambient light, the illuminance output of the lighting device is controlled to increase based on the detected illuminance value, so that it is written on the end surface of the object. Characters can be read under appropriate illumination. In addition, even when the illuminance decreases due to deterioration or dirt of the light source / reflector of the lighting device, it is possible to always ensure the optimum illuminance for reading characters, and it is possible to read characters easily and reliably. .

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an entire character reading device to which the present invention is applied.

[Explanation of symbols]

 1 Image Sensor 2 Steel Material 2a End Face 3 Characters 4 Illuminance Sensor 5 Illumination Device 6 Signal Processing Device

Front page continued (72) Inventor Eiji Matsukuma 46-59 Nakahara, Tobata-ku, Kitakyushu City Nippon Steel Corporation Machinery & Plant Division

Claims (1)

[Claims] 1. A character reading device for reading a character written on an end surface of an object, comprising: a character reading image sensor provided facing the end surface of the object; and irradiating the end surface of the object. Illumination device, an illuminance sensor installed in the vicinity of the end face of the object, and a control device for increasing / decreasing the irradiation output of the illumination device based on the detection value of the illuminance sensor. Character reader.