JPS63193666A - Image reader - Google Patents

Abstract

PURPOSE:To eliminate a need for a microswitch for detecting the position of a reader part by providing a read start mark in a position immediately before a read start position, detecting this mark by the reader part, and controlling the start of reading an original corresponding to a detection signal. CONSTITUTION:The read start mark 12 is provided at a place immediately before the read start position that is within an area to be read by the optical reader block 4. When a start button is depressed, the block 4 starts a read operation, and runs as outputting read signals; upon reading the mark 12, the block 4 outputs a signal to a control part. Thereafter, at such a point of time that the read position of the block 4 reaches the foremost end of an original platen, read signals from an image sensor are outputted from the control part as image signals, and thus the reading of an original is executed. As a result, a need for a microswitch for detecting the position of the reader part can be eliminated, and the cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a stationary original image reading device in an image scanner, facsimile machine, or the like.

2. Description of the Related Art Conventionally, as shown in FIG. 5, an image reading device such as an image scanner has a transparent document table 2 on which a document 1 is placed, a document presser 32'-- which presses the document 1 against the document table 2, and a document presser 32'-- which presses the document 1 against the document table 2. A fluorescent lamp 5 for illumination, an image sensor 6 for reading a document, and a lens 7 for forming an image on the image sensor 6
, an optical reading block 4 equipped with a mirror 8 for changing the direction of light, a linear motor 9 and a linear motor guide 10 for moving this optical reading block 4 along the document table 2, and detecting the position of the optical reading block 4. The optical reading block 4 is moved along the document table 2 by a linear motor 9 to read the document. Further, the original reading start position at that time is set based on the detection signal of the microswitch 11.

Problems to be Solved by the Invention However, with this configuration, there is a problem in that a microswitch must be provided to detect the position of the optical reading block, and furthermore, it is necessary to adjust the microswitch. In other words, if the position of the microswitch is different from the position of the document table, there will be an error in the timing of starting document reading, and a part of the document may not be read or parts other than the document may be In order to prevent this, it was necessary to inspect and adjust the variations.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an image reading device that does not use a microswitch for detecting the position of an optical reading block, and therefore does not require adjustment of the microswitch. purpose.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention includes a document table on which a document is placed, a reading section that runs along the document table, reads the document, and outputs a reading signal. In a document reading device equipped with a reading movement unit that moves the reading unit along a document table, a reading start mark indicating a reference position for starting reading is provided within a reading area of the reading unit and before the reading start position; The reading unit is configured to read this mark,
The apparatus further includes a control means for detecting the reading start mark from the reading signal from the reading section and controlling the start of reading the document according to the detection signal.

According to the above-described structure, when the reading unit moves along the document table to read the original, the reading unit starts reading from the front side of the original and outputs a reading signal, and The control means detects the reading start mark from the reading signal and determines that the reading section has passed the reading start mark position, and then the reading section moves a distance corresponding to the distance between the reading start mark and the edge of the document. It is possible to control the document reading to start when the document is read. As a result, the start of document reading can be controlled without using a microswitch, and the adjustment of the conventional microswitch is completely unnecessary.

Example Hereinafter, the present invention will be described in detail as shown in the drawings.

FIG. 1 is a side view showing a schematic configuration of an image reading apparatus according to an embodiment of the present invention, in which 1 is a document to be read, 2 is a transparent document table on which the document 1 is placed, and 3 is a transparent document table on which the document 1 is placed. The original plate 4 is an optical reading block constituting a reading unit that runs along the original platen, reads the original, and outputs a reading unit 5-7. The optical reading block 4 includes a fluorescent lamp 5 for illuminating the original, an image sensor 6 for reading the original, a lens 7 for forming an image on the image sensor 6, a mirror 8 for changing the direction of light, and the like. 9 is a linear motor, and 10 is a linear motor guide, which move the reading optical block 4 to the document table 2.
A reading movement unit is configured to move the image along the .

Reference numeral 12 denotes a reading start mark, which is provided within the reading area of the optical reading block 4 and in front of the reading start position (the position of the leading edge of the document placed on the document table 2). FIG. 2 is a bottom view showing the reading start mark 12 and a part of the document table 2. In this embodiment, the reading start mark 12 is used in the direction of movement of the optical reading block 4 during reading (reading direction).
A mark in which a white portion 12A and a black portion 12B are lined up is used. Here, the width of the white portion 12A and the black portion 12B in the reading direction A is the width that can be resolved by the optical reading block 4, and the distance between the starting end of the black portion 12B and the starting end 2a of the document table 2! are set at predetermined intervals. Note that the reading start mark 12 is not limited to the one shown in the drawings, but may be any mark as long as it can be recognized from the reading signal from the optical reading block 4.

FIG. 3 is a block diagram schematically showing the main parts of the control circuit of the image reading apparatus configured as described above. Reference numeral 13 denotes a binarization circuit that binarizes the output signal from the image sensor 6 according to white pixels and black pixels, and 14 inputs the read signal from the binarization circuit 13 to a predetermined number of bits (n number of pits). 15 is an AND circuit that outputs a signal when the n-bit signal taken out from the shift register 14 indicates a black pixel; 16 is an AND circuit that stores the n-bit signal taken out from the shift register 14; O outputs a signal when indicating a white pixel
The R circuit 17 is a control section that inputs the read signal from the binarization circuit 13 and outputs it as an image signal to a recording section (not shown) or the like.

The operation of the image reading apparatus configured as above will be explained with reference to the flowchart of FIG. 4.

In FIG. 1, the optical reading block 4 has its reading 7'.-
7 Waiting at a position where the reading position is to the left of the reading start mark 12. When the start button is pressed, a motor pulse is first applied to the linear motor 8, and the optical reading block 4 starts moving rightward. When the number of pulses reaches a specified value, the optical reading block 4 starts a reading operation, and the image sensor 6 outputs a reading signal. At this time, the prescribed value of the pulse is determined so that the reading position is at or before the white part of the reading start pattern 12.

After that, the optical reading block 4 runs while outputting a reading signal, and when the white part 12A of the mark 12 is read and the dot part 12B is read, the AND circuit 15 outputs a signal to the control section 17. Thereafter, when the number of pulses applied to the motor reaches the specified number 9 and the reading position by the optical reading block 4 reaches the starting edge 2a of the document table 2, the reading signal from the image sensor is output from the control unit 17 as an image signal. and the document is read. The optical reading block 4 moves along the document table 2 while reading the original, and when the number of pulses corresponding to the length of the original is counted, it stops outputting both signals and stops the reading operation by the optical reading block 4. Then, return the optical reading block 4 to its original position. This completes one document reading operation.

Effects of the Invention As is clear from the above description, the present invention includes a document table on which a document is placed, a reading section that runs along the document table, reads the document, and outputs a reading signal, and a document table that connects the reading section to the document table. In the document reading device, a reading start mark indicating a reference position for starting reading is provided within the reading area of the reading unit and before the reading start position, and the reading unit moves this mark. configured to read,
Furthermore, the system is configured to detect the reading start mark from the reading signal from the reading unit and control the start of document reading according to the detection signal, so it is no longer necessary to use a microsinch to detect the position of the reading unit as in the past. This eliminates the need for troublesome adjustment of microswitches, which has the effect of reducing costs.

[Brief explanation of the drawing]

9'・-7 FIG. 1 is a schematic side view of an image reading device according to an embodiment of the present invention, FIG. 2 is a bottom view showing a reading start mark and part of the document table used in the device, and FIG. FIG. 4 is a block diagram schematically showing a control circuit of the device, FIG. 4 is a flowchart showing the operation of the device, and FIG. 5 is a schematic side view of a conventional image reading device. 1... Original, 2... Original table, 2a... Starting edge, 4...
・・Optical reading flock, ・・Fluorescent light, 6・・Image sensor, 8・・Linear motor, 9・・Linear motor guide, 12・・・Reading start mark

Claims (1)

[Claims] A document table on which a document is placed, a reading section that runs along the document table, reads the document, and outputs a reading signal, a reading moving section that moves the reading section along the document table, and a reading area by the reading section. a reading start mark provided within the reading start position and in front of the reading start position; and a control means for detecting the reading start mark from a reading signal from the reading section and controlling the start of document reading in accordance with the detection signal. Image reading device.