JPH0339981Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an image reading device that uses an image sensor such as a CCD to read an image on a microfilm or the like and convert it into an electrical image signal.

[Background and purpose of the idea]

In an image reading device, an original such as a microfilm is illuminated with a lamp, and reflected light or transmitted light from the original is received by an image sensor made of a solid-state image sensor. Generally, the illumination section of a document becomes hot due to the heat from the lamp, and in order to prevent discoloration of the document, burn-in, overheating of the device, etc. due to this heat, a ventilation fan is provided. I'm trying to cool it down.
Conventionally, this fan is driven all the time, so when an image sensor reads an image, the image cannot be read correctly due to vibrations caused by the fan, and for this reason, when printing is performed using the output signal of the image sensor, the printed image is There was a problem with quality deterioration. Especially if the device generates a large amount of heat,
For example, when illuminating a 35mm microfilm, a large capacity light source is required, which causes the illumination unit to become hot, which necessitates the use of two or more fans. There was a drawback that the image was greatly blurred. For this reason, there was a problem in that the structure of the device was complicated in order to eliminate the vibration of the fan.

The present invention aims to solve the above problem, and is characterized in that the drive of the fan is stopped or driven at a low speed to reduce vibration when reading an image.

〔composition〕

The present invention will be explained below with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of the present invention. A light source 1 irradiates a film 2 with light, and a projected image thereof is formed on a light receiving surface of an image sensor in a line image sensor section 6 via a lens 3 and a half mirror 4. The light partially reflected by the half mirror 4 is projected onto a monitor screen 5. Here, the optical path length from the second surface of the film to the light receiving surface of the image sensor section 6 and the optical path length from the second surface of the film to the screen 5 are set to be equal. this is,
This is because the size of the projected image on the image sensor section 6 is equal to that of the projected image.

Check the size of the projected image on screen 5, etc.
The user operates the operation unit 8 to input necessary data into the microcomputer 9. The microcomputer 9 processes the input data and sets the main scanning speed and range and the sub-scanning speed and range of the image sensor. Based on the set value, the motor of the image sensor unit 6 is driven via the motor drive circuit 11 to move the image sensor, thereby controlling the sub-scanning speed of the image sensor. Also, via the image sensor drive circuit 10, the video signal output range is controlled according to the main scanning speed and range of the image sensor, as well as the sub-scanning range. The video signal from the image sensor section 6 is sent to the signal processing section 7 and becomes a digitalized image signal.

Further, the lighting section including the light source 1 is air-cooled by a fan 15 to prevent the lighting section from becoming hot. The fan 15 is controlled by a signal from the microcomputer 9 via a fan motor drive circuit 16.

When observing a film image illuminated by a light source on the screen 5, a fan drive signal is output from the microcomputer 9, and this signal drives the fan 15 via the fan motor drive circuit 16 to cool the illumination section. Ru.

Next, when a reading start command is given to the operation unit 8 to read the image, a reading start signal is output from the microcomputer 9. This signal causes the image sensor 6 to read the image via the image sensor drive circuit 10, and the motor drive circuit The image sensor 6 moves via the image sensor 11. On the other hand, at the start of reading, a fan stop signal is issued from the microcomputer 9, and the fan 15 is stopped by this signal. Therefore, since the fan stops when reading an image with the image sensor, vibration of the film or the image sensor is prevented, and the image can be read correctly with the image sensor. When the image reading is completed, the fan 15 is driven again. The fan 5 stops only while the image is being read, and the stopping period is short, so the fan is restarted before the illumination section reaches a high temperature, and there is no risk of the film being discolored or burned.

In the above embodiment, the image sensor is moved to perform sub-scanning, but the image sensor is fixed and
Sub-scanning may be performed by moving the microfilm.

Furthermore, if a two-dimensional area sensor is used as the image sensor, sub-scanning driving is not required.

In the above embodiment, the drive of the fan is stopped when reading an image, but instead of stopping when reading an image, it may be driven at a low speed so that the vibration is small enough not to interfere with image reading. .
In addition, multiple fans are installed, and all of the fans are driven when not reading, and some of the fans are stopped when reading. Alternatively, only the fans may be driven.

〔effect〕

As described above, according to the present invention, images can be read correctly without vibrations that would be a hindrance during image reading, and overheating of the illumination unit, discoloration of the document, and burn-in can be prevented.

[Brief explanation of the drawing]

The figure is a configuration diagram of an image reading device showing one embodiment of the present invention. 2...Micro film, 6...Image sensor, 15...Fan.

Claims (1)

[Scope of utility model registration request] In an image reading device that uses an image sensor to read an image illuminated by an illumination unit having an illumination lamp, a fan for air-cooling the illumination unit;
An image reading device comprising: means for controlling driving of the fan to be stopped or driven at a low speed when an image is read by an image sensor, and for driving the fan at a high speed when an image is not to be read.