JPH03136569A - Picture reader - Google Patents

Abstract

PURPOSE:To miniaturize the reader by storing a picture which is obtained through subscanning (rotation of cylinder) in a video memory for one pattern and controlling a write address and a readout address inverting horizontal/ vertical data. CONSTITUTION:A original 2 wound on a cylinder 1 is lighted uniformly from a linear scanning light source 4 like a fluorescent light, its reflected light is inputted to a CCD image sensor 6 through a lens 5, in which photoelectric conversion is applied and the light is converted into an electric signal. The main scanning is implemented by the self scanning of the CCD image sensor 6, while the subscanning is executed by the drive of a subscanning motor 3. A small sized original of nearly 190mmX130mm is subscanned along the side of 190mm side, and the write address and the readout address of an one picture memory 23 are controlled inverting horizontal/vertical data thereby matching the scanning direction.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a cylindrical scanning type image reading device.

[Conventional technology]

The conventionally used cylindrical scanning type image reading device is
As shown in the figure, an original 42 wrapped around a transmission cylinder 41 is main-scanned by the rotation of a main-scanning motor 43 and converted into an electrical signal, while sub-scanning is performed by a feed screw 45 of an optical system 44 to cover the entire screen of the original 42. is what is being scanned. Further, as shown in FIG. 5, light from a linear light source 53, such as a fluorescent lamp, which irradiates one main scanning length of the transmission document, is directed onto the surface of the transmission document 52 placed flat on the transmission document table 51. The reflected light is input to, for example, a CCD image sensor 55 through a lens 54, and main scanning is performed by self-scanning of the image sensor. (not shown) is rotated by a sub-scanning motor to move the document table 51 to scan the entire screen of the document 52.

[Problem to be solved by the invention]

In the conventional image reading apparatus described above, the conventional example shown in FIG. 4 has the disadvantage that high-speed scanning is not possible due to performance limitations of the sub-scanning motor and the problem of peeling of the original. Further, the conventional example shown in FIG. 5 has the disadvantage that the device size in the sub-scanning direction needs to be at least twice as large as the original, making it unsuitable for miniaturization of the device.

[Means to solve the problem]

The image reading device of the present invention includes a cylinder around which a document is wrapped, a linear scanning light source that illuminates the document, a CCD image sensor as a photoelectric conversion element, and a one-screen memory that stores one screen of image data. In the image reading device, main scanning is performed by self-scanning of the CCD image sensor, sub-scanning is performed by rotating the cylinder, and the obtained image data is stored in the one screen memory, and the write address and readout of the one screen memory are performed. Vertical and horizontal conversion is performed by controlling the address.

〔Example〕

Next, the present invention will be explained with reference to the drawings. 1 and 2 are a perspective view and a block diagram of an embodiment of the present invention.

In FIG. 1, a document 2 wrapped around a cylinder 1 is uniformly irradiated by a linear scanning light source 4 such as a fluorescent lamp, and the reflected light is inputted to a CCD image sensor 6 through a lens 5, where it is photoelectrically converted. and becomes an electrical signal. Main scan is C
The self-scanning of the CD image sensor 6 is performed, and the universal scanning is performed by the rotation of the sub-scanning motor 3.

In FIG. 2, an image signal photoelectrically converted by a CCD image sensor 21 is converted into a digital signal by an A/D converter 22 and stored in a one-screen memory 23.
The output of the screen memory 23 is processed by the output interface circuit 24, for example, if it is compatible with an analog line, processing such as amplitude modulation is performed. What is shown in Figure 0, which shows a document for an image reading device used in a company or the like, is a small document of about 190 mm x 130 mm. In the conventional apparatus, the 190 mm side is the main scanning direction, and the 130 mm side is the sub scanning direction. FIG. 3(b) shows the scanning direction in this embodiment.
By controlling the write address and read address of the screen memory 23, vertical and horizontal conversion is performed to match the scanning direction.

〔Effect of the invention〕

As explained above, according to the present invention, the length of the cylinder may be the dimension in the short side direction of the document, so that the apparatus can be miniaturized. In addition, since the cylinder only needs to rotate once, the cylinder rotates at a low speed and has the effect of enabling high-speed scanning without the problem of document peeling.

Sensor, 23... 1 screen memory, 43... Main scanning motor, 44... Optical system, 45... Feed screw, 51...
...Manuscript table.

Claims (1)

[Claims] Main scanning is performed using a CCD in an image reading device that is equipped with a cylinder around which a document is wrapped, a line-shaped scanning light source that illuminates the document, a CCD image sensor as a photoelectric conversion element, and a one-screen memory that stores one screen of image data. Image data obtained by self-scanning of the image sensor is performed by rotating the cylinder, and the obtained image data is stored in the one-screen memory, and vertical and horizontal conversion is performed by controlling the write address and read address of the one-screen memory. An image reading device characterized by performing the following.