JPH0523660B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] In an apparatus that reads a conveyed document by arranging a plurality of reading element groups consisting of a plurality of reading elements in a straight line, installation errors between the reading element groups, etc. By providing marks for correcting output deviation due to this on a transparent plate-like member placed opposite the platen member to prevent the document from floating, accurate deviation correction can be performed even in the case of document transport type. And so.

[Industrial application field]

The present invention relates to an image reading device that reads images by arranging a plurality of image sensors in a line, and particularly relates to an image reading device of a document conveying type that is capable of accurately correcting deviations in the sub-scanning and main scanning directions at the seam of each image sensor. The present invention relates to an image reading device.

With the development of the information society, various image reading devices have been developed and used. Some of these image reading devices use a CCD as an image sensor. By the way, there is a limit to the size of a CCD, and when reading a small size image, one
A CCD would suffice, but for large images, multiple CCDs are used and these are added together.

For example, an image reading device that reads AI drawings at a reading density of 400 dots/inch uses two 5K-bit CCDs, aligns the two CCDs mechanically, and uses one 10,000-bit CCD. configured as if you were using it.

[Conventional technology]

FIG. 7 is a diagram illustrating the positioning of a conventional CCD.

For example, as shown in FIG. 7a, assume that a line 1 written on a manuscript is read by the CCD 3 through the lens 2, half of the line 1, and the CCD 5 reads the remaining half of the line 1 through the lens 4. . In this case, the original and
Although it is easy to mechanically fix the distance to the CCD accurately, a deviation occurs in the read data between the CCD 3 and the CCD 5 due to their relative positions.

That is, as shown in FIG. 7a, for example, CCD3 and
Even if CCD5 is installed parallel to line 1,
If there is a misalignment of the document in the feeding direction,
Even if the read lines are parallel, they will be shifted in the sub-scanning direction.

In addition, as shown in Fig. 7c, one of the read lines is inclined with respect to the other and the seams overlap, as shown in Fig. 7d, the line is inclined and separated from each other, and a combination of these is possible. Occur.

Conventionally, while observing the outputs of CCDs 3 and 5 for overlap or separation of line 1, inclination in two directions, and deviation in the sub-scanning direction, printed board unit 6 with CCD 3 attached and printed board unit 6 with CCD 5 attached are checked. 7 and were manually moved and adjusted.

[Problem that the invention seeks to solve]

As mentioned above, conventional adjustment is done manually, but even if the amount of deviation is adjusted, it does not follow the changes in ambient temperature.
Since the CCD mounting member expands and retracts, there is a problem that misalignment occurs during the reading of a large number of sheets.

At this time, with the fixed document table type, it is possible to perform accurate correction by reading the correction mark provided on the document table each time one sheet is read. However, with the document feed type, since correction marks are added to the document, only designated paper can be used, and if the document floats, etc., accurate correction cannot be performed. I had a problem.

In view of the above-mentioned conventional problems, an object of the present invention is to
An object of the present invention is to provide a document conveying type image reading device that can accurately correct the misalignment of a reading element even if it is a document conveying type.

[Means for solving problems]

As shown in the diagram explaining the principle of the present invention in FIG.
a transparent plate-like member 4 provided at a position facing the platen member 3 with the original 1 sandwiched therebetween so as to prevent the original 1 from floating; and a reader comprising a plurality of linearly arranged reading elements. A reading member 5 in which a plurality of element groups 5a and 5b are arranged on the plate-like member 4 side so that the reading positions are substantially in a straight line; and a reading mark 6 having a directional component perpendicular to the direction, and reciprocating the plate-like member 4 in the conveyance direction,
means 7 for positioning the reading mark 6 at the reading position A and the non-reading position B; correcting the reading output between the reading element groups 5a and 5b according to the reading result of the reading mark 6 by the reading member 5; This is achieved by a document conveying image reading device including a correction section 8 that performs the following steps.

[Effect]

As described above, in the present invention, the platen member 3 for preventing the document 1 from floating and the transparent plate member 4 are provided at the reading position A of the reading member 5.
Since the reading mark 6 is provided on the plate-like member 4, it is a simple operation of positioning the plate-like member 4 at the reading position A using the positioning means 7 every time a sheet of the original is read. , it becomes possible to perform accurate correction.

〔Example〕

Embodiments of the document conveyance type image reading apparatus according to the present invention will be described in detail below with reference to the drawings.

FIG. 2 is a diagram showing the overall configuration of the embodiment.

In the figure, 1 is a document, for example, an AO size document, 10a, 10b, 10c, 10d are conveyance rollers, and the conveyance roller 10a is a motor 11.
The document 1 sandwiched between the conveyance roller 10b and the conveyance roller 10c is rotated by the motor 11 and conveyed to the reading position A.
The document 1 sandwiched between the roller 10d and the roller 10d is ejected from the reading position A to the stacker section. 1
2a, 12b, 12c, 12d are guide members that guide the original 1; B is a platen roller with a white surface that regulates the position of the original 1; 14 is a glass member that guides the original 1; By sandwiching the document 1 between the roller 13,
A reading mark 15 is used to prevent the original 1 from lifting up at the reading position A, and for example, as shown in FIG. and one provided at the non-reading position B of the glass member 14, 16
a and 16b are fluorescent lamps that illuminate the original 1; 17a and 17b are heater plates;
18a and 18b are reflective mirrors that guide the reflected light from the reading position A; 19 is a lens; 20a and 20b are CCD drive units; A CCD group 21a, 2 in which CCDs are arranged in a straight line.
1b for reading the reading areas l ₁ and l ₂ as shown in FIG. 3, and 22 a video signal processing circuit which quantizes the light reception signal from the CCD drive unit.
The one that outputs one bit at a time, 23 is the MPU,
It has internal memories M ₁ and M ₂ that individually store the outputs from the CCD groups 21a and 21b, respectively, and stores the reading results of the reading marks in the internal memories M ₁ and M ₂ so that the outputs from the CCD groups 21a and 21b can be stored. Calculate the amount of deviation,
24 is a heater that heats the heater plates 17a and 17b;
5 is an inverter that lights up the fluorescent lamps 16a and 16b; 26 is a conveyance motor driver that drives the conveyance motor 11; 27 is a glass member moving motor driver;
Motor 28 for reciprocating 4 in the arrow direction X
A sensor 29 detects the arrival of the document 1.

In the configuration described above, first, the sensor 29
When the arrival of document 1 to be read is detected by
1 is not driven and conveyance of the document 1 is stopped, the glass member 14 is moved via the driver 27 and the motor 28.
to move the reading mark 15 to the reading position A.

Then, this reading mark 16 is placed on the CCD group 21.
a and 21b, and the respective reading results are stored in the internal memory of the MPU 23. FIG. 4 shows the results of storage into the internal memory.

FIG. 4 is a diagram showing a part of the internal memory, and the diagram shows the state of the internal memory that stores the vicinity of the reading mark out of the reading results read by the CCD groups 21a and 21b and stored in the internal memory. It is.

Furthermore, in order to reduce the capacity of the internal memory, it is possible to store only a predetermined area from the right end of the reading area _l1 and a predetermined area from the left end of the reading area _l2 for a predetermined distance in the main scanning direction. The installation of
The difference will not be as large as the difference, so be sure to
A shift between the CCD groups 21a and 21b can be detected.

Here, by the adjustment work described above, CCD group 2
If the distance from the right end of the reading area l1 of _1a to the transport direction component 16a of the reading mark 16 is the same as the distance from the left end of the reading area _l2 of the CCD group 21b to the transport direction component 16a of the reading mark 16, , the storage address (X address) of the transport direction component 16a of the read mark 16 stored in the internal memories _M1 and _M2 , respectively.
and the storage address (Y address) of the main scanning direction component 16b are the same.However, due to the influence of temperature changes, etc.
As shown in the figure, based on the CCD group 21a side, for example, the X address is 1 bit (shift in the main scanning direction), and the Y address is Y ₂ - _{Y 1} = 2 bits (shift in the transport direction, 2 lines). If it is off,
The MPU 23 performs deviation correction as follows.

FIG. 5 is a diagram showing a deviation correction circuit in the transport direction, which is provided inside the MPU 23.
30a, 30b, and 30c are shift registers in which the outputs of the CCD group 21a are stored;
Those shifted by the number of bits (5 kbit) of the CCD group 21a, 31a, 31b, 31c, 31d, 3, respectively.
1e is a shift register in which the output of the CCD group 21b is stored;
32 is a multiplexer that shifts the number of bits (5 kbit), and shift registers 31a to
33 is a multiplexer that selects either the multiplexer 32 or the shift register 30c, and 34 is a register in which a value for switching the output of the multiplexer 32 is stored. be.

In the configuration described above, since there is a two-line shift in the transport direction as described above, the MPU 23 sets the value of the register 34 based on the calculation result so that the output of the multiplexer 32 becomes the shift register 31e. The deviation can be corrected by

That is, since there are two more shift register groups 31a to 31e than shift register groups 30a to 30c, if the outputs of CCD groups 21a and 21b are input at the same time, the output to the multiplexer 33 will be from the shift register groups 31a to 31e. Since there is a delay of two lines, correction is possible.

Note that Y of the CCD group 21b is different from that of the CCD group 21a.
If the address is small, for example, Y ₂ -Y ₁ =-1 bit, the multiplexer 32 may select the shift register 31b. Furthermore, if the amount of shift is two or more lines, the difference in the number of shift register groups may be increased.

FIG. 6 is a diagram showing a deviation correction circuit in the main scanning direction, which is provided inside the MPU 23.
36 is a register in which the offset value in the main scanning direction determined by the MPU 23 (in the example of FIG. 4, "1" bit) is set; 37 is a register in which the number of bits (read ₃₈ is an adder which adds the value of register 37 and the value of register 36. , 39 are counters that are reset immediately before the first bit of the video signal output from the CCD group 21a is input, and count up in synchronization with the bit shift. 40 is a comparator that A flip-flop 41 which compares the output with the output of the counter 39 and outputs an output when they match, is set by a match output from the comparator 40 and inverts the output, and outputs an output when they match. l When the CCD output corresponding to the left edge of ₂ is obtained, the MPU
The switch circuit 35 is reset by the reset signal outputted from the flip-flop 23, and is composed of multiplexers 32 and 33 shown in FIG.

In the configuration described above, as mentioned above,
Since there is a +1 bit shift in the main scanning direction, "1" is set in the register 36. The comparator 40 is
When one extra bit is output from the CCD group 21a, the FF 41 is inverted and the output of the multiplexer 33 is transferred from the CCD group 21a side.
The correction is performed by switching to the CCD group 21b side.

That is, the shift register groups 31a to 31e on the CCD group 21b side are bit shifted when the shift register group 30c reaches a predetermined number of bits, so by causing the CCD group 21a side to output one extra bit, Corrections can be made.

In this way, the glass member 14 is moved in the document transport direction (arrow Y direction in FIG. 3), the reading mark 16 is read, the amount of deviation is calculated, and the result is set in the registers 34 and 36. , the deviation of the CCD groups 21a and 21b can be automatically corrected.

Further, after moving the glass member 14 in the Y direction and reading the reading mark, the MPU 23 moves the glass member 14 through the driver 27 and the motor 28.
Return to the position shown in Figure 2.

Then, via the driver 26 and the motor 11,
Drive the conveyance roller 10a. Then, the document 1 is conveyed to the reading position A, and the image is read.

Thereafter, by repeating the above-described operations, images can be input without misreading even if the ambient temperature changes.

Furthermore, in this embodiment, since the reading mark 16 is provided on the platen roller 13 side of the glass member 14, even more accurate correction can be performed.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to accurately correct misalignment between reading elements even in an image reading apparatus of a document conveyance type.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the principle, Fig. 2 is an overall configuration diagram of the embodiment, Fig. 3 is an explanatory diagram of reading marks, Fig. 4 is a diagram showing the storage results in the internal memory, and Fig. 5 is a diagram of the transport direction. Figure 6 shows the deviation correction circuit in the main scanning direction. Figure 7 shows the conventional CCD.
It is a figure explaining position alignment. In the figure, 1 is a document, 2 is a transport section, 3 is a platen member, 4 is a transparent plate member, 5 is a reading member,
6 is a reading mark, 7 is a positioning means, and 8 is a correction section.

Claims (1)

[Claims] 1. A transport section 2 that transports the original 1 to the reading position A;
a platen member 3 provided at the reading position A; a transparent plate-like member 4 provided at a position facing the platen member 3 with the original 1 in between so as to prevent the original 1 from floating; a reading member 5 in which a plurality of reading element groups 5a and 5b each consisting of a plurality of arrayed reading elements are arranged on the plate-like member 4 side so that the reading positions are substantially in a straight line; a reading mark 6 which is provided and has a component in the conveying direction of the document 1 and a component in a direction perpendicular to the direction; and reciprocating the plate member 4 in the conveying direction;
means 7 for positioning the reading mark 6 at the reading position A and the non-reading position B; and means 7 for positioning the reading mark 6 at the reading position A and the non-reading position B; and controlling the reading output between the reading element groups 5a and 5b according to the reading result of the reading mark 6 by the reading member 5. A document conveyance type image reading device including a correction section 8 for correction.