JPH099015A - Reading method for document reading device and document reading device to which the method is applied - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a simple and inexpensive document reading device that can effectively capture image data even when the document reading timing and position detection are operated asynchronously. In this document reading apparatus, a drive signal φ is output from the drive circuit 2 at a constant cycle regardless of the scanning distance of the reading position and transmitted to the image sensor 1 and the determination circuit 4. The document reading position detecting means 3 outputs a detection signal E as a result of detecting the document reading position according to the sub-scanning line density accompanying the movement of the reading position of the document in the sub-scanning direction, and transmits it to the determination circuit 4. The image sensor 1 outputs an image signal V for each line at a constant cycle in response to the drive signal φ and transmits the image signal V to the determination circuit 4. The determination circuit 4 reads 1 according to the drive signal φ input immediately after the detection signal E is input from the image signal V for each line regardless of the sub-scanning line density.
The lines are output in order while discriminating the effective image signals V _e .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading method for a document reading apparatus having a scanner section represented by a hand scanner for manually scanning a document and reading image data of the document, and a document reading apparatus to which the method is applied. Regarding

[0002]

2. Description of the Related Art Conventionally, in a facsimile apparatus or a copying apparatus known as a general document reading apparatus, a scanner section is fixed inside the apparatus main body, and a document is read while being conveyed at a constant speed. In the case of the reading method in such an apparatus, a drive signal having a constant cycle is input to a light receiving element as a reading element included in the scanner unit.

On the other hand, in the case of a reading system in which the scanner unit is separated from the main body of the apparatus and the document is manually scanned, as in the case of a document reading apparatus having a scanner unit such as a hand scanner, the light receiving element of the scanner unit is used. For example, a drive signal with a variable cycle is input according to the movement of the document reading position.

FIG. 3 is a block diagram showing the circuit configuration of a conventional document reading apparatus disclosed in Japanese Patent Laid-Open No. 61-85955. Further, FIG. 4 is a timing chart showing processed signals in the respective parts, FIG. 4A shows the detection signal E, FIG. 4B shows the synchronization signal E ′ and the drive signal φ, and FIG. c) relates to the effective image signal V _e .

In this document reading device, as shown in FIG. 4A, the document reading position detecting means 3 is used as a scanning distance of the document reading position in the sub-scanning direction according to the sub-scanning line density for reading the document. The detection signal E indicating the detection result at a constant interval is output and transmitted to the control circuit 5.
In addition, as shown in FIG.
Then, a synchronizing signal E ′ synchronized with the detection signal E is output and transmitted to the driving circuit 2, and the driving circuit 2 outputs a driving signal φ according to the synchronizing signal E ′ from the control circuit 5 to generate an image as a scanner unit. Transmit to sensor 1. Furthermore, as shown in the image sensor 1 FIG. 4 (c), the but outputs the effective image signal V _e corresponding to the drive signal phi, the sub-scanning without depending on the effective image signal V _e is always scanning speed It is obtained as a signal synchronized with the linear density.

[0006]

In the case of the document reading apparatus provided with the scanner unit such as the hand scanner described above, a synchronization signal which is always synchronized with the detection signal regarding the document reading position is generated in order to obtain a drive signal for controlling the image sensor. Therefore, there is a problem that the circuit configuration becomes complicated and the cost becomes high because it is necessary to provide a control circuit for performing the operation.

The present invention has been made in order to solve such a problem, and its technical problem is that image data can be effectively taken in even when timing and position detection relating to document reading are operated asynchronously. An object of the present invention is to provide a reading method for a document reading device which has a simple and inexpensive circuit and a document reading device to which the reading method is applied.

[0008]

According to the present invention, there is provided a reading method for a document reading device, which manually scans a document by a scanner section having a reading element to which a drive signal is inputted and reads image data from the document, A drive signal is continuously generated at a constant cycle in order to cause the reading element to perform a reading operation for each line, and a sub-scanning line density for reading the document is set as a scanning distance of a document reading position in the sub-scanning direction. In response to the drive signal of the constant period, the reading element is continuously operated at the constant period regardless of the position of the document in scanning the document according to the drive signal of the constant period. One line worth of image data read immediately after the detection signal is input according to the movement of the reading position on the original from the image data of each line in response to the drive signal of a constant cycle is effective. Document reading apparatus for reading method takes in is obtained.

On the other hand, according to the present invention, a reading element to which a drive signal of a constant cycle is input is provided, and a scanner unit for manually scanning a document and reading image data from the document, and a document in the sub-scanning direction. In a document reading apparatus including a document reading position detecting unit that generates a detection signal indicating a result of detection at a constant interval as a scanning distance of a reading position according to a sub-scanning line density for reading the document, In order to perform the reading operation line by line, a drive circuit for continuously generating a drive signal with a constant cycle is provided, and the scanner unit has a reading element irrelevant to the position of the document when scanning a document according to the drive signal with a constant cycle. Thus, there is obtained a document reading apparatus which is continuously operated at a constant cycle and outputs an image signal including image data for each line at a constant cycle.

Further, according to the present invention, in the above-mentioned document reading apparatus, the image signal of each line is read immediately after the detection signal is input in accordance with the movement of the reading position on the document according to the drive signal of a constant cycle. An original reading device provided with a determination circuit for taking in one line's worth as valid and outputting an effective image signal is obtained.

[0011]

EXAMPLES Examples will be given below to describe a reading method for an original reading apparatus of the present invention and an original reading apparatus to which the same is applied.
A detailed description will be given with reference to the drawings.

First, the outline of the reading method for a document reading apparatus of the present invention will be briefly described. This reading method for a document reading device is such that when image data is read from a document by manually scanning the document with a scanner unit having a reading element to which a drive signal (a variable period is conventionally used) is input,
A drive signal is continuously generated at a constant cycle in order to cause the reading element to perform a reading operation line by line, and a sub-scanning line density for reading a document is set as a scanning distance of a document reading position in the sub-scanning direction. Generate a detection signal indicating the result of detection at a constant interval, and according to the drive signal of a constant cycle, the reading element is continuously operated at a constant cycle irrespective of the position of the document when scanning the document, and a drive signal of a constant cycle is also generated. Accordingly, one line worth of image data read immediately after the input of the detection signal accompanying the movement of the reading position on the document is effectively taken in from the image data of each line.

FIG. 1 is a block diagram showing a circuit configuration of an original reading device according to an embodiment to which the reading method for the original reading device of the present invention is applied. 2 is a timing chart showing processed signals in the respective parts, FIG. 2 (a) relates to the drive signal φ, and FIG.
The signal, the figure (c) relates to the image signal V, and the figure (d) relates to the effective image signal V _e .

This document reading device is provided with a reading element to which a drive signal φ of a constant cycle is input, and manually scans the document to read image data from the document and output an image signal V containing the image data. An image sensor 1 as a scanner unit and a document reading position detection that generates a detection signal E indicating a result of detection at a constant interval according to a sub scanning line density for reading a document as a scanning distance of a document reading position in the sub scanning direction. Means 3, a drive circuit 2 for continuously generating a drive signal φ having a constant cycle for performing a reading operation on the reading element line by line, and an image for each line according to the drive signal φ having a constant cycle captures those from the image signal V containing data for one line read immediately after the input of the detection signal E in accordance with the movement of the reading position on the document as valid, effective image signal V _e And a decision circuit 4 to be output.

That is, in the image sensor 1 here, the reading element is continuously operated at a constant period during scanning of the document in accordance with the drive signal φ at a constant period regardless of the position of the document, and the image signal V is changed to 1 at a constant period. Output for each line. As a result, the image data can be effectively taken in even when the timing and position detection relating to document reading are operated asynchronously.

Therefore, the operation of the original reading position will be briefly described below with reference to the timing charts of the processing signals in the respective portions shown in FIGS. 2 (a) to 2 (d).

First, the drive circuit 2 outputs a drive signal φ as shown in FIG. 2A at a constant cycle regardless of the scanning distance of the reading position, one of which is transmitted to the image sensor 1 and the other. Is transmitted to the determination circuit 4. Further, as shown in FIG. 2B, the document reading position detecting means 3 detects the document reading position corresponding to the sub-scanning line density accompanying the movement of the reading position of the document in the sub-scanning direction. The detection signal E is output and transmitted to the determination circuit 4. Further, the image sensor 1 outputs the image signal V for each line in a constant cycle as shown in FIG.

Therefore, in the judging circuit 4, regardless of the sub-scanning line density, for example, the Low regarding the detection signal E from the image signal V for each line output from the image sensor 1
The one line portion as shown in FIG. 2D, which is read in accordance with the drive signal φ input immediately after the level or High level timing, is sequentially output while being determined as the effective image signal V _e .

[0019]

As described above, according to the reading method for the original reading apparatus of the present invention, the reading operation of the original and the reading position detecting operation are asynchronously independent, and the reading position of the original is detected. Since effective image data for one line is obtained from the image data for each line read by continuous operation according to the signal, reading of indeterminate sub-scanning line density such as reading while manually scanning the document Image data can be effectively obtained with no unevenness in feeding even in operation, and a document reading apparatus to which this is applied can be provided at a low cost with a simple circuit configuration.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of a document reading apparatus according to an embodiment to which a reading method for a document reading apparatus of the present invention is applied.

2A and 2B are timing charts showing processing signals in respective parts of the document reading apparatus shown in FIG. 1, where FIG. 2A is for a drive signal, and FIG. 2B is for a detection signal.
(C) relates to an image signal, and (d) relates to an effective image signal.

FIG. 3 is a block diagram showing a circuit configuration in a conventional document reading apparatus.

4A and 4B are timing charts showing processing signals in respective parts of the document reading apparatus shown in FIG. 3, where FIG. 4A is for detection signals, FIG. 4B is for synchronization signals and drive signals, and FIG. It relates to an image signal.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 image sensor 2 drive circuit 3 original reading position detection means 4 determination circuit 5 control circuit V image signal V _e effective image signal φ drive signal E detection signal E ′ synchronization signal

Claims (3)

[Claims] 1. A reading method for a document reading device for manually scanning a document and reading image data from the document by a scanner unit having a reading element to which a drive signal is inputted, wherein a reading operation is performed for the reading element. The drive signal is continuously generated at a constant cycle so as to be performed for each line, and the scanning distance of the document reading position in the sub-scanning direction is detected at a constant interval according to the sub-scanning line density for reading the document. A detection signal indicating the result is generated, the reading element is continuously operated in a constant cycle regardless of the position of the original in scanning the original according to the drive signal in the constant cycle, and in response to the drive signal in the constant cycle. A feature that one line worth of image data read immediately after the detection signal is input according to the movement of the reading position on the original document is effectively taken in from the image data of each line And a reading method for a document reading device. 2. A scanner unit that is provided with a reading element to which a drive signal of a constant cycle is input, and a scanner unit that manually scans a document to read image data from the document, and a scanning distance of a document reading position in the sub-scanning direction. In a document reading device provided with a document reading position detecting means for generating a detection signal indicating a result of detection at a constant interval according to a sub-scanning line density for reading the document, a reading operation is performed for the reading element by one. A drive circuit for continuously generating the drive signal of the constant cycle is provided for each line, and the scanner section is irrelevant to the position of the document when the document is scanned according to the drive signal of the constant cycle. An original reading apparatus characterized in that it is continuously operated at a constant cycle to output an image signal containing the image data for each line at the constant cycle. Place. 3. The document reading apparatus according to claim 2,
An effective image signal is obtained by taking as an effective one line image read immediately after the detection signal is input according to the movement of the reading position on the document from the image signal for each line in response to the drive signal of the constant cycle. An original reading device comprising a determination circuit for outputting the.