JPH02155366A - Picture reader - Google Patents

Abstract

PURPOSE:To improve the scanning speed and the communication speed by scanning a part (photograph or graph or the like) requiring details of an original at a high line density and scanning a part not requiring details such as a character part with a coarse line density. CONSTITUTION:An original 4 passes through a read section 1 by a pulse motor 2 and an original feed system 3. The read section 1 reads a picture of the original 4 in the unit of lines. A control circuit 7 inputs a coordinate and a line density in operation information c from an operation panel 6, calculates the scanning speed, outputs a control signal B to a pulse generating circuit 5 and changes the frequency of a motor drive pulse A to the pulse motor 2 in response to the read range thereby changing the line density. A read picture data D is sent to a picture signal transmission section via a picture signal processing circuit 8. In this case, a coordinate and line density information F from the control circuit 7 are sent to the picture signal transmission section together with a picture data at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image reading device, and particularly to a facsimile image reading device.

[Conventional technology]

Conventionally, this type of image reading device reads each page at the same linear density, so in the case of an original with text and photographs mixed on one page, it is necessary to use a high linear density to read the details of a photographic original. I was reading one page.

[Problem to be solved by the invention]

The conventional image reading device described above reads the entire page at the same linear density, so even when reading a part of the page in detail, the entire page is read at a high linear density, which reduces the reading time and data transmission time. The disadvantage is that it is very expensive.

[Means to solve the problem]

The variable linear density image reading device of the present invention includes a reading section that reads a document line by line and converts it into an electric signal, a document feeding type for passing the document through the reading section, a pulse motor, and a pulse motor. A pulse generation circuit that can change the pulse frequency of the document using control information, an operation panel and key switches that can specify the reading range and linear density of the document at multiple locations, and a control panel and key switches that can input information from the operation panel and key switches to set the specified reading range. a microcomputer that controls a series of operations such as calculating the number of pulses and frequency of the reading, changing the linear density in that range, and transmitting the read image signal together with the coordinates of the specified reading range, the coordinates of the linear density, and the linear density information; It consists of a control circuit consisting of peripheral circuits, and the part where details of the manuscript are required (Photo 2)
Figures, tables, etc.) are scanned at a high line density, and portions that do not require fineness, such as text, are controlled to be scanned at a rough line density.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention.

In FIG. 1, a document 4 is moved by a pulse motor 2. The document passes through the reading section 1 by the document feed system 3. The reading unit 1 reads the image of the original 4 line by line. The control circuit is composed of a microcomputer and peripheral circuits, and includes an operation panel 6.
Enter the coordinates and linear density from . The designated contents of the coordinates and linear density are shown in FIG. In Fig. 2, locus 1 (xo, y,), (x,, y+) of reading range α, linear density M
1ine/mm, coordinates of reading range β (XO, Ml
), (M,, Y2), and linear density N 1ine/mm can be specified using the operation panel 6 shown in FIG. 1 above.

The control circuit 7 in FIG. 1 inputs the coordinates and linear density of the operation information C from the operation panel 6, calculates the scanning speed, outputs the control signal B to the pulse generation circuit 5, and outputs the reading range α
, β to the motor drive pulse A to the pulse motor 2 according to
The linear density is changed by changing the frequency. The read image data D is sent to the image signal sending section via the image signal processing circuit 8. At this time, the coordinates and linear density information F from the control circuit 7 are simultaneously sent to the image signal sending section along with the image data (E).

〔Effect of the invention〕

As described above, the present invention has the effect that by changing the reading linear density of a document midway through the document, the scanning speed and communication speed can be improved and the document can be transmitted quickly.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a diagram showing an example of a read document. 1...reading unit, 2...pulse motor, 3...document feeding system, 4...document,
5... Pulse generation circuit, 6... Operation panel, 7... Control circuit, 8... Image signal processing circuit, A... Motor drive pulse, B...
・Control signal, C...operation information, D...
Image data, E... Image data, F...
・Coordinates and linear density information, X o, Y o...
・Original origin, X+, Y+...End point in X and Y directions of reading range A, X,, Y,...Start coordinates of reading range B, X 1. Y2...End point of reading range B. Agent: Susumu Uchihara, patent attorney

Claims (1)

[Claims] an image reading unit that reads a document for each main scanning line and converts it into an electrical signal; a pulse motor and a document feeding mechanism that move the document at a constant speed with respect to the image reading unit;
A pulse generation circuit for driving a pulse motor that can control the oscillation frequency using external control information, a control circuit that controls the oscillation frequency of this pulse generation circuit in accordance with a predetermined sub-scanning line density, and an arbitrary and plural number of pulse generators on the document surface. The control circuit comprises a sub-scanning section and an operation panel for inputting an arbitrary settable scanning line density corresponding to this sub-scanning section, and the control circuit controls the line density in the sub-scanning direction arbitrarily and according to information from the operation panel. An image reading device characterized by having a function of changing in a plurality of sub-scanning sections.