JPH09247386A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the mounting and fixing operation and handling of each line image sensor and read an image of high quality at all times. SOLUTION: This device is provided with a read line correcting means 40A which corrects respective effective image data, read by a previous-array line image sensor 32 and following-array line image sensors 31 and 33, as respective effective image data read on a virtual common read line y2v in the direction of vertical scanning (Y) and on the downstream side of a following-array read line y2, and respective errors of the position shift of a previous-array line image sensor 32 from a previous-array read line y1 and position shifts of following- array line image sensors 31 and 33 from a following-array read line y2 are removed to read the object image out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to at least one or more front row line image sensors arranged along a front row reading line in the sub-scanning direction and two or more rear row line images arranged along a rear row reading line. An image to be read as a composite of the effective image data belonging to the effective reading range of each line image sensor that has a sensor and is scanned by the front line image sensor and the rear line image sensor in the main scanning direction and read by each line image sensor. The present invention relates to an image reading device for reading an image.

[0002]

2. Description of the Related Art There is known an image reading apparatus for reading an image to be read on a document which is relatively movable in the sub-scanning direction by an image scanner. In such an image reading apparatus, a plurality of line image sensors in which image scanners are arranged in the main scanning direction are used when the entire effective reading range is large, for example, A2 size paper size or larger, regardless of whether the original feeding method or the original fixing method is used. Are formed from.

That is, for example, FIG. 7 showing a document conveying system.
, The front row line image sensor 32 is attached along the front row reading line y1 extending in the main scanning (X) direction on the upstream side in the sub scanning (Y) direction, and the rear row reading line y2 extending in the X direction on the downstream side. Two rear row line image sensors 31, 33 are attached along the line image sensors 31, 32, 33 so that the readable areas of the adjacent line image sensors 31, 32, 33 are overlapped by x1. And each line image sensor 3
Effective reading range RA1, RA2, RA3 of 1, 32, 33
Are divided within each overlap readable area (x1). That is, the entire effective reading range RA of the image scanner 30 is established as a combination of the respective effective reading ranges RA1, RA2, RA3.

Thus, the image to be read printed on the document 70 conveyed in the Y direction is read by each line image sensor 3.
1, 32, 33 are scanned in the X direction, and the reading target is a combination of the valid image data belonging to the valid reading ranges RA1, RA2, RA3 in the image data read by the line image sensors 31, 32, 33. The image can be read.

By the way, the front row line image sensor 32
And the rear row line image sensors 31 and 33 are arranged in a staggered manner in the Y direction, so that they have consistency as shown in FIG. That is, when a read pulse is generated from the read pulse generator 21 in the control unit 10 at time T1, the front row line image sensor 32 immediately reads the image to be read. The effective image data in the read image data is analog-digital converted by the A / D converter 39 and stored and held in the memory 42P.

When the document 70 is conveyed in the Y direction and reaches time T2, the read pulse delayed by the read delay circuit 22 is output, so that the rear row line image sensor 3 is operated.
1, 33 read the image to be read. Each valid image data is analog-digital converted by the A / D converter 39.

Here, the synthesizing circuit 20P has the rear row line image sensor 31, the front row line image sensor 32, and the rear row line image sensor 33 lined up in the X direction in order of the effective image data at time T2 and on the rear row reading line y2. Combine as read. That is, the image to be read on the original 70 can be read by one apparent scan.

Even when there are two or more front row line image sensors or three or more rear row line image sensors, a memory (42P) is provided for each front row line image sensor and a read delay circuit ( 22) is provided.

Here, the delay time of the read delay circuit 22 is
The test pattern (straight line) 63 extending in the X direction printed on the test chart 60 shown by the two-dot chain line in FIG.
Each line image sensor 31, 32, while being conveyed in the direction
When the effective image data read in 33 is combined, the read image is selected and set so as to be the same as the test pattern 63. The storage capacity of the memory 42P is increased in proportion to the distance d from the front row read line y1 to the rear row read line y2.

Thus, in order for the combined read image to be the same as the test pattern 63, the read pixel row 32E of the front row line image sensor 32 is positioned on the front row read line y1 and the rear row line image sensors 31, 3 are arranged.
Each of the read pixel rows 31E and 33E of 3 is the read row y2 in the rear row.
Positioning on top is a prerequisite.

However, each read pixel row 32E, 31E, 3
It is difficult to visually confirm 3E. Therefore, each line image sensor 32, 31, 33 is positioned and fixedly attached to each reading line y1, y2 by using a perforating jig into which each line image sensor 32, 31, 33 can be inserted. A great deal of labor and time is spent on mounting and fixing,
And it requires careful work.

[0012]

However, no matter how carefully the mounting and fixing work is performed, it may not be possible to meet the demand for higher quality reading. Further, even if the request is once met, the effective image data read by the front row line image sensor 32 and the rear row may be changed if the entire environment of the apparatus is changed, the layout is changed at the installation location, or the operating environment changes such as temperature change. A deviation in the Y direction occurs between the effective image data read by the line image sensors 31 and 33. The same occurs between the front row line image sensors and between the rear row line image sensors. Therefore, it is difficult to handle.

It is an object of the present invention to provide an image reading apparatus which is easy to mount and fix and to handle, and which can always read a high quality image.

[0014]

According to an analysis through a number of actual machines, if the dimensions of each line image sensor (for example, 31) are length L × width 2W shown in FIG. 9, both length L and width 2W are obtained. Manufacturing dimensional error is recognized. Length L
With respect to the error, there is no problem because the overlapping readable area (x1) is provided in the X direction, but the influence of the error of the width 2W cannot be ignored. In particular, the fact that the tolerance ΔW (for example, ± 0.05 mm) is recognized in the dimension W from the side edge to the read pixel row 31E (specifically, the best focus point) has a great influence on image reading quality. .

That is, the read pixel row 31E is 1 in the X direction.
Assuming that the resolution is 6 dots / mm, when a straight thin line image on the original 70 similar to the test pattern 63 having a width in the Y direction of 4 dots (0.25 mm) extending in the X direction is read, Tolerance of each line image sensor ΔW (±
Depending on the combination of (0.05 mm) in the Y direction, a step difference of, for example, 2 dots occurs.

According to the present invention, the effective image data read by each front row line image sensor and each rear row line image sensor from the above analysis results is converted into a virtual common reading line downstream of the rear row reading line in the Y direction. Formed so that it can be corrected as each valid image data read,
Y for each reading line of each line image sensor
It is possible to read by removing the positional deviation error in the direction.

That is, according to the invention of claim 1, at least one or more front row line image sensors arranged along the front row reading line in the sub-scanning direction and two or more rear row lines arranged along the rear row reading line. And an image sensor, which scans the front-row line image sensor and the back-row line image sensor in the main scanning direction and reads them by each line image sensor, and reads them as a composite of each effective image data belonging to the reading effective range of each line image sensor. In an image reading apparatus for reading a target image, each of the effective image data read by each of the front row line image sensors and each of the rear row line image sensors is virtually shared in the sub-scanning direction and downstream of the rear row reading line. A reading line correction hand that corrects each valid image data read on the reading line The image to be read can be read by removing the respective errors of the positional deviations of the front row line image sensors with respect to the front row reading lines and the respective positional deviations of the rear row line image sensors with respect to the back row reading lines. It is characterized in that it is configured.

In such an invention, each front row line image sensor on the front row reading line and each rear row line image sensor on the rear row reading line read effective image data in the same manner as in the conventional example. Therefore, at this stage, if each front row line image sensor is displaced in the sub-scanning direction from the front row read line, each effective image data includes a displacement error in the sub-scanning direction. The same applies when each rear row line image sensor is displaced in the sub-scanning direction from the rear row reading line.

Here, the reading line correction means corrects each effective image data read by each line image sensor as effective image data read in the sub-scanning direction and on the virtual common reading line downstream of the rear row reading line. Therefore, it is possible to eliminate the error of the positional deviation of each line image sensor with respect to each reading line in the sub-scanning direction.
High-quality images can always be read, and the work of mounting and fixing each line image sensor and handling are easy.

According to a second aspect of the present invention, the reading line correcting means includes the effective image data read by the front row line image sensors in the front row read line and the rear row line image sensors in the rear row read line. The respective individual image memories capable of storing each of the respective effective image data read, and the respective effective image data read in the virtual common reading line from the respective effective image data stored in each individual memory. The image reading device is formed of respective memory holding delay circuits of variable delay amount for respectively holding and holding each memory.

In this invention, each effective image data read by each front row line image sensor in the front row reading line is stored in each individual memory. Thereafter, each effective image data read by each rear row line image sensor in the rear row reading line is also stored in each individual memory. Each effective image data stored in each individual memory is delayed while being stored and held up to the virtual common read line by each storage and holding delay circuit. Thus, by synthesizing the respective effective image data at the timing when the virtual common reading line is reached, the positional deviation of each line image sensor with respect to each reading line can be automatically corrected.

Therefore, the same operation and effect as in the case of the invention of claim 1 can be obtained, and the delay amount (time) of each memory holding delay circuit is appropriately set by using, for example, the test pattern of the test chart. It is easier to handle because it only needs to be placed.

According to a third aspect of the present invention, the read line correction means includes the effective image data read by the front row line image sensors in the front row read line and the rear row line image sensors in the rear row read line. Each of the effective image data read by can be stored in all the memories, and each effective image data is adjusted in the virtual common reading line by adjusting each read timing of each of the effective image data stored in all the memories at the time of combining. The image reading device is formed so as to be able to correct each read valid image data.

In the case of such an invention, each effective image data read by each front row line image sensor in the front row read line and each effective image data read by each rear row line image sensor in the back row read line are directly stored in the entire memory in that order. Remembered. Then, at the time of combining, the reading timing of each effective image data is adjusted and read so that each effective image data is each effective image data read in the virtual common reading line.

Therefore, in addition to the same operation and effect as the case of the invention of claim 1, the read timing at the time of synthesizing each effective image data is set to the position of each line image sensor (read pixel) and the virtual common read line. Since it is only necessary to set each of them in relation to the above, handling is simpler and the number of parts can be reduced as compared with the case of the invention of claim 2.

According to a fourth aspect of the present invention, a rear row line image sensor located on the most downstream side in the sub-scanning direction among the respective rear row line image sensors is used as a reference line image sensor, and the reference line image sensor is the above. The image reading device is disposed downstream of the rear row reading line in the sub-scanning direction and displaced by the dimension tolerance of the respective rear row line image sensors in the sub-scanning direction.

In the above invention, one of the rear row line image sensors is a reference line image sensor which is displaced from the rear row reading line on the downstream side in the sub-scanning direction by a dimensional tolerance. If the one located first in the main scanning direction is selected, the subsequent processing of each effective image data read by each line image sensor can be facilitated. Therefore, in addition to the same operational effects as in the case of the inventions of claims 1 to 3, the selection of the virtual common read line is simpler.

Further, in the invention of claim 5, the rear row line image sensor located on the most downstream side in the sub-scanning direction among the rear row line image sensors is used as a reference line image sensor, and the read pixels of the reference line image sensor. In the image reading device, a row is arranged on the virtual common reading line.

In this invention, the read pixel row of the reference line image sensor is arranged on the virtual common read line, in other words, the axis line passing through the read pixel row of the reference line image sensor and extending in the main scanning direction is arranged. It can be a virtual common read line.

Therefore, in addition to the same operational effects as in the case of the first to fourth aspects of the invention, the correction of the reference line image sensor of the reading line correction means can be omitted, which further simplifies the processing and parts. The points can be reduced.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) As shown in FIGS. 1 and 2, the present image reading device subscans (Y) each effective image data read by the front row line image sensor 32 and the rear row line image sensors 31, 33. ) Direction and downstream of the rear row read line y2, the read line correction means 40A for correcting each valid image data read on the virtual common read line y2v is provided, and the front row line image sensor 32 is displaced with respect to the front row read line y1. The rear row line image sensors 31 and 33 are configured to be able to read the image to be read by removing the respective errors of the positional deviations with respect to the rear row read line y2.

In FIG. 1, the front row read line y1 and the rear row read line y2 are separated by a distance d (for example, 26.7 ± 1 m).
m) apart in the Y direction. One front row line image sensor 32 and two rear row line image sensors 31 and 33 are mounted and fixed to the front row reading line y1 and the back row reading line y2 by using the perforating jig described in the conventional example. The tolerance from the side edge of each image sensor 31, 32, 33 to the best focus point is ± 0.5 m.
m. The number of line image sensors in the rear row is 2
(31, 33) and the number of front row line image sensors is 1
The reason why the number is reduced as (32) is to reduce the capacity of the individual memory described later in detail.

In the mounted / fixed state, the read pixel row 32E of the line image sensor 32 has the front row read line y1.
Is displaced upstream in the Y direction, the read pixel row 31E of the rear row line image sensor 31 is displaced downstream in the Y direction from the rear row read line y2, and the read pixel row 33E of the rear row line image sensor 33 is rear row. Reading line y
It is assumed that the position shifts to the upstream side of Y in the Y direction.

The virtual common read line y2 is assumed to be located downstream of the rear row line image sensor 31 (more specifically, the read pixel row 31E) located on the most downstream side in the Y direction of the rear row line image sensors 31 and 33. ing.

The reading line correction means 40A is an individual memory 4 corresponding to each line image sensor 32, 31, 33 provided in the control unit 10 shown in FIG.
2, 41, 43 and memory holding delay circuits 52, 51, 53.

The individual memory 42 can store the effective image data read by the front row line image sensor 32 at the front row read line y1 at time T1. Individual memory 41
(43) can store the effective image data read by the rear row line image sensor 31 (33) in the rear row read line y2 at time T2. Each individual memory 41, 42,
The storage capacity of 43 is the same as that of the line image sensors 31, 32, 33 (read pixel rows 31E, 32E, 3) shown in FIG.
3E) and the distance d31, d between the virtual common reading line y2v
It is increased in proportion to 32 and d33.

The memory holding delay circuit 52 is provided in the individual memory 42.
The effective image data stored in the virtual common reading line y2v is held and delayed so as to be the effective image data read on the virtual common reading line y2v. That is, the reading target image on the document 50 read by the front row line image sensor 32 is delayed by the time t32 when it is conveyed to the virtual common reading line y2v.
That is, this memory holding delay time t32 is understood to be the time required for the document 50 to advance by the distance d32.

Further, the memory holding delay circuit 51 (53) is
The effective image data stored in the individual memory 41 (43) is held and delayed so that it is the effective image data read on the virtual common reading line y2v. That is, the image to be read on the document 50 read by the rear row line image sensor 31 (33) is delayed by the time t31 (t33) when it is conveyed to the virtual common reading line y2v. That is,
The storage retention delay time t31 (t33) is understood as the time required for the document 50 to advance by the distance d31 (d33).

Storage retention delay times t31, t32, t3
Test chart 6 shown in FIG. 1 for use for setting 3 and optimizing each set value and judging the adequacy of each set value.
At 0, the test pattern (straight line) 61 and the test pattern (straight line) 62 have a dimension d (for example, 26.7 mm).
It is printed with a separation of ± 0.1 mm. The width t in the Y direction of each test pattern 61, 62 is 0.25 mm in this embodiment.

Therefore, each line image sensor 3
Since the tolerance of 1, 32, 33 is ± 0.5mm above,
The storage capacity of the individual memories 41 and 43 is theoretically 0.25 m
It suffices if it is equivalent to m. In this embodiment, in consideration of the deviation of the linearity due to subsequent changes over time and temperature,
It is equivalent to 0.5 mm. The storage capacity of the individual memory 42 is larger than the capacity corresponding to the distance d by 0.5 mm.

Thus, while the test chart 60 is stopped using this test chart 60, the front row line image sensor 32 is caused to read the test pattern 61 and the individual memory 42 stores the effective image data, and each rear row The test pattern 62 is read by the line image sensors 31 and 33, and each individual memory 41,
43 to memorize. However, each individual memory 41, 42,
As in the case of the conventional example, it is impossible to read the effective image data stored in 43 as the same as the test pattern 62 even if they are combined as they are, as in the case of the conventional example. Each line image sensor 3
This is because 1, 32, 33 (31E, 32E, 33E) are displaced from the respective reading lines y2, y1, y2.

Therefore, in order to pretend that the reading is performed on the virtual common reading line y2v, that is, to correct, the memory holding time t31, t32, t33 of each memory holding circuit 51, 52, 53 of variable delay (time) type. Change (adjust) the settings for each. This process is repeated until the read image data after combination becomes the same as the test pattern 61. For example, repeat 3 times.

In the first embodiment having such a configuration, the original 7
When 0 is conveyed in the Y direction, when the reading pulse is generated from the reading pulse generator 21 at time T1, the front row line image sensor 32 on the front row reading line y1 reads the reading target image. The valid image data is converted into a digital signal by the A / D converter 39 and stored in the individual memory 42. The memory holding delay circuit 52 delays this by the set memory holding time t32.

Further, at the time T2 when the original 70 is conveyed in the Y direction, the delayed reading pulse is output from the reading delay circuit 22, so that the rear row line image sensor 31 is provided.
Reads the image to be read that has moved to the rear row reading line y2. This effective image data is converted into a digital signal and stored in the individual memory 41. The memory holding delay circuit 51 delays by the set memory holding time t31.

Similarly, the rear row line image sensor 33 on the rear row reading line y2 reads the image to be read. This effective image data is converted into a digital signal and stored in the individual memory 43. The memory holding delay circuit 53 delays by the set memory holding time t33.

Thus, the storage retention times t31, t3
When 2, t33 are timed up all at once on the apparent virtual common reading line y2, effective image data read by the rear row line image sensor 31 by the synthesizing circuit 20,
The effective image data read by the front row line image sensor 32 and the effective image data read by the rear row line image sensor 33 are read and combined in this order.

That is, the reading line correction means (41, 5
1, 42, 52, 43, 53) each of the effective image data read by each of the line image sensors 31, 32, 33 in the sub-scanning (Y) direction and on the downstream side of the rear row reading line y2, the virtual common reading line y2v. Since it is corrected as the effective image data read in, each line image sensor 32,
It is possible to remove the error of the positional deviation of the reading lines y1 and y2 of the reference numerals 31 and 33 in the Y direction.

According to the first embodiment, however,
Each valid image data read by the front row line image sensor 32 and each rear row line image sensor 31, 33 is read in the sub scanning (Y) direction and on the virtual common reading line y2v downstream of the rear row reading line y2. Read line correction means 40 for correcting as image data
By providing A, it is possible to read the image to be read by removing each error of the positional deviation of the front row line image sensor 32 with respect to the front row reading line y1 and the respective positional deviations of the rear row line image sensors 31 and 33 with respect to the rear row reading line y2. Since it is configured, it is possible to always read high-quality images, and it is easy to mount and fix each line image sensor and to handle it.

Further, each memory holding delay circuit 51, 52, 5
The delay amount of 3 (time t31, t32, t33) need only be set appropriately using, for example, the test patterns 61 and 62 of the test chart 60, so that the handling is easier.

Further, each line image sensor 31, 3
Since it is not necessary to worry about the tolerances of 2, 33, the cost can be reduced, and the mounting and fixing work can be simplified, which can further reduce the cost.

Further, the individual memories 41, which have a small storage capacity,
43 and storage retention delay circuits 51 and 5 for delaying only for a short time
Since it is sufficient to provide 2, 53, it can be realized at low cost. The individual memory 42 is the memory 42 of the conventional example.
It is almost the same as P.

Further, each memory holding delay circuit 51, 52, 5
Since 3 is a variable delay amount (time), it is widely applicable, and the resolution in the Y direction can be set to 0.125 mm or less by using the test pattern 62 of 0.25 mm, for example.

(Second Embodiment) In the second embodiment, as shown in FIG. 3, in the case of the first embodiment (4 in FIG. 2).
The reading line correcting means 40B different from 0A) is provided. In addition, each line image sensor 31, 32, 33
Etc. are the same as the case shown in FIG.

In FIG. 3, the control unit 10 has a CP
U11, ROM12, RAM13, EPROM14, timer 15, DMAC16, including the interface (I / F) 17 for data communication with the host machine (not shown) connected via the data communication line 1, the paper feed motor 35,
A sheet conveying means including the driver 35D and the image scanner 30 (line image scanners 31, 32, 3)
3) The image reading means including each A / D converter 39 can be drive-controlled in a timely manner to read the image to be read on the original 70. The synthesizing means is composed of the CPU 11 and the ROM 1.
2 are formed.

Here, the reading line correction means 40B includes the entire memory 13M and the read timing adjustment control means 11 and 1.
2 and 14 are formed.

The entire memory 13M is formed in the RAM 13 and can store each effective image data read by each line image sensor 32, 31, 33 with time. That is, effective image data writing control means (CPU 11, ROM
12) shows the effective image data output from each A / D converter 39 shown in FIG.
Store it in M.

The read timing adjustment control means is composed of a ROM 12 and a C storing a read timing adjustment control program.
PU11 and EPROM for storing read timing data
It is possible to read each effective image data which is formed by 14 and is stored in the entire memory 13M as being read by the virtual common reading line y2v.

Each read timing can be changed by operating a key (not shown) on the keyboard. That is, the valid image data read by the front row line image sensor 32 on the front row read line y1 at time T1 and the valid image data read by the respective rear row line image sensors 31, 33 on the back row read line y2 at time T2,
This means the timing (or the order) at which one scan can be performed in the X direction on the virtual common read line y2v.

In other words, since the effective image data read by each line image sensor 32, 31, 33 for each scanning is continuously stored in the entire memory 13M, each line image sensor 32, 31, Each valid image data read in 33 is shifted with time and each reading line y
Line image sensors 32, 31,
The position shift of 33 is also shifted with time. The reading line correction means 40B reads at a timing at which an error due to this positional deviation can be removed.

According to the second embodiment, however,
In addition to achieving the same operation and effect as in the case of the first embodiment,
Further, if the read timing at the time of synthesizing each effective image data is set in accordance with the relationship between the position of each line image sensor 31, 32, 33 (read pixels 31E, 32E, 33E) and the virtual common read line y2v. Since it is good, it is easier to handle, and each line image sensor 31, 3
Since the individual memories 41, 42, 43 and the storage holding delay circuits 51, 52, 53 for each 2, 33 are not required, the number of parts can be reduced and the cost can be reduced as compared with the case of the first embodiment.

(Third Embodiment) In FIG. 4, the front row reading line y1 is provided with three front row line image scanners 32, 34 and 36, and the back row reading line y2 is provided with four back row line image scanners 31 ,. 33, 35,
37 are provided.

Therefore, when the reading line correction means 40A is adopted, each line image sensor 31 to 37 is used.
An individual memory (41 to 47) and a storage holding delay circuit (51 to 57) may be provided for each. Each storage retention time (t31 to t37) to be delayed is equal to the virtual common read line y2.
It is set as corresponding to each distance d31 to d37 to v.

When the read line correction means 30B is adopted, the read timing of each effective image data for each line image sensor 31 to 37 may be set.

Thus, even if the number of line image scanners is large, the same operational effect as in the case of the first and second embodiments can be obtained, and further, it can be easily applied to upsizing in the main scanning (X) direction. Since the effect of reducing the careful mounting and fixing work becomes large, the cost of the entire apparatus can be significantly reduced.

(Fourth Embodiment) This fourth embodiment is different from the first (or second) embodiment in that a reference line image sensor is placed on a virtual common read line y2v as shown in FIG. The difference is that [31 (31E)] is provided.

The reference line image sensor (31) is determined to be located on the most downstream side in the Y direction of the rear row line image sensors 31 and 33. In terms of mounting and fixing work, the first rear row line image sensor 31 in the X direction may be arranged more actively downstream than the other (33).

Further, each rear row line image scanner 3
After arranging Nos. 1 and 33, the axis line (y2v) passing through the read pixel row 31E (best focus point) of the rear row line image sensor 31 on the most downstream side is set to the virtual common read line y2v.
Should be selected as

Therefore, according to the fourth embodiment,
In addition to the same operational effects as in the case of the first (or second) embodiment, the reading line correction means 40A (40) is further provided.
Since the correction of the reference line image sensor (31) in B) can be omitted, the processing can be further simplified and the number of parts (41, 51) can be reduced.

(Fifth Embodiment) This fifth embodiment is shown in FIG. In this embodiment, the arrangement position of the rear row line image sensor 31 is further specified as compared with the case of the third embodiment (FIG. 4).

That is, as in the case of the fourth embodiment, the rear row line image sensors 31, 33, 35, 37 are arranged.
The rear row line image sensor 31 located on the most downstream side in the Y direction is used as a reference line image sensor, and the reference line image sensor (31) is arranged on the downstream side in the Y direction with respect to the rear row reading line y2. They are arranged so as to be displaced by the dimensional tolerance ΔW of 31, 33, 35, 37 in the Y direction.

Thus, the rear line image sensor 3 other than the reference line image sensor (31) is provided.
Since 3, 35, and 37 are not located on the downstream side in the Y direction, the virtual common reading line y2v may be determined with reference to the reference line image sensor (31), so that the selection is easy.

Further, in the fifth embodiment, the reference line image sensor (31) is arranged on the virtual common line y2v as in the case of the fourth embodiment (FIG. 5).

Therefore, according to the fifth embodiment,
In addition to the same operational effects as in the case of the first to third embodiments, the virtual common read line y2v can be selected more easily and the same operational effects as in the case of the fourth embodiment can be achieved.

[0074]

According to the first aspect of the present invention, each effective image data read by each front row line image sensor and each rear row line image sensor is virtually shared in the sub-scanning direction and on the downstream side of the rear row reading line. A reading line correction unit that corrects each valid image data read in the reading line is provided, and each positional deviation of each front row line image sensor with respect to the front row reading line and each positional deviation of each rear row line image sensor with respect to the rear row reading line. Since the image to be read can be read by removing the error, it is possible to remove the error of the positional deviation of each line image sensor with respect to each read line in the sub-scanning direction. Therefore, a high-quality image can be read at all times, and the work of mounting and fixing each line image sensor and the handling thereof are easy. Furthermore, the cost of the entire apparatus can be reduced by simplifying the mounting and fixing work.

According to the second aspect of the present invention, the reading line correcting means reads each effective image data read by each front row line image sensor in the front row read line and each rear row line image sensor reads in the rear row read line. Each individual memory capable of storing each of the effective image data and each storage and delay of each effective image data stored in each individual memory are stored and delayed so as to be each effective image data read on the virtual common reading line. Since each effective image data is composed at the timing when the virtual common reading line is formed, the positional deviation of each line image sensor with respect to each reading line is automatically generated because it is formed by each delay holding type memory holding delay circuit. Can be corrected. Therefore, the same effect as in the case of the invention of claim 1 can be obtained, and the delay amount (time) of each memory holding delay circuit need only be properly set by using, for example, the test pattern of the test chart. , Easier to handle.

According to the third aspect of the present invention, each effective image data read by each front row line image sensor in the front row read line by the read line correction means and each valid image data read by each rear row line image sensor in the rear row read line. Each effective image data can be stored in all the memories and each effective image data read in the virtual common reading line by adjusting each read timing of each effective image data stored in all the memories at the time of composition. Since it is formed so that it can be corrected as described above, the read timing of each effective image data at the time of combining is adjusted so that each effective image data is each effective image data read in the virtual common read line, and the read is performed. be able to. Therefore,
In addition to the same effect as in the case of the invention of claim 1, the read timing at the time of synthesizing each effective image data is further determined depending on the relationship between the position of each line image sensor (read pixel) and the virtual common read line. Since it is sufficient to set it, handling is easier and the number of parts can be reduced as compared with the case of the invention of claim 2.

According to the invention of claim 4, the rear row line image sensor located on the most downstream side in the sub-scanning direction among the respective rear row line image sensors is used as the reference line image sensor, and the reference line image sensor is arranged in the rear row. The reference line image sensor is located at the first position in the main scanning direction, for example, because it is arranged downstream of the reading line in the sub scanning direction with a positional deviation in the sub scanning direction of each rear row line image sensor. If selected, subsequent processing of each effective image data read by each line image sensor can be facilitated. Therefore, the same effects as those of the inventions of claims 1 to 3 can be obtained, and selection of the virtual common read line is simpler.

Further, according to the invention of claim 5, the rear row line image sensor located on the most downstream side in the sub-scanning direction among the respective rear row line image sensors is used as the reference line image sensor, and the read pixel of this reference line image sensor is used. Since the columns are arranged on the virtual common read line,
An axis line that passes through the read pixel row of the reference line image sensor and extends in the main scanning direction can be set as a virtual common read line. Therefore, the same effects as in the case of the inventions of claims 1 to 4 can be obtained, and further correction of the reference line image sensor of the reading line correction means can be omitted, which further simplifies the processing and reduces the number of parts. it can.

[Brief description of drawings]

FIG. 1 is a plan view showing a first embodiment of the present invention.

FIG. 2 is likewise a block diagram for explaining a reading line correction means.

FIG. 3 is a block diagram for explaining reading line correction means according to a second embodiment of the present invention.

FIG. 4 is a plan view showing a third embodiment of the present invention.

FIG. 5 is a plan view showing a fourth embodiment of the present invention.

FIG. 6 is a plan view showing a fifth embodiment of the present invention.

FIG. 7 is a plan view for explaining a conventional example.

FIG. 8 is a block diagram for explaining a conventional example.

FIG. 9 is a diagram for explaining the problems of the conventional example.

[Explanation of symbols]

10 Control Unit 11 CPU 12 ROM 13 RAM 13M All Memory (Reading Line Correction Means) 14 EPROM 20 Combining Circuit 21 Read Pulse Generator 22 Reading Delay Circuit 31 Rear Line Image Sensor (Reference Line Image Sensor) 33, 35, 37 Rear Line Image sensor 32, 34, 36 Front row line image sensor 39 A / D converter 40A Reading line correction means 41-43 Individual memories 51-53 Storage retention delay circuit 40B Reading line correction means 60 Test chart 61, 62 Test pattern 70 Original X Main Scanning direction Y Sub-scanning direction y1 Front row reading line y2 Rear row reading line y2v Virtual common reading line ΔW Tolerance

Claims (5)

[Claims] 1. At least one front row line image sensor arranged along a front row reading line in the sub-scanning direction and two or more rear row line image sensors arranged along a rear row reading line, An image reading apparatus for reading a read target image as a combination of valid image data belonging to a valid reading range of each line image sensor by scanning the front row line image sensor and the rear row line image sensor in the main scanning direction. In each of the effective image data read by the front row line image sensor and each rear row line image sensor, each effective image read in a virtual common reading line in the sub-scanning direction and downstream of the rear row reading line. A reading line correction means for correcting as data is provided, and each front row line The image to be read is configured to be readable by removing the respective errors of the positional displacement of the image sensor with respect to the front row reading line and the respective positional deviations of the respective rear row line image sensors with respect to the rear row reading line. Image reading device. 2. The valid image data read by the front row line image sensors in the front row read line and the valid images read by the rear row line image sensors in the rear row read line by the read line correction means. Each individual memory capable of storing each data, and delay for storing and delaying each effective image data stored in each individual memory so as to be each effective image data read on the virtual common read line The image reading apparatus according to claim 1, wherein the image reading apparatus is formed of a variable amount storage holding delay circuit. 3. The effective image data read by the front row line image sensors in the front row read line and the valid images read by the rear row line image sensors in the rear row read line by the reading line correction means. Effective image data obtained by reading each effective image data in the virtual common read line by adjusting each read timing of each effective image data stored in all memories when each data can be stored in all memories It is formed so that it can be corrected as follows.
The image reading device according to claim 1. 4. The rear row line image sensor located on the most downstream side in the sub-scanning direction among the respective rear row line image sensors is used as a reference line image sensor, and the reference line image sensor is used as the sub line rather than the rear row reading line. 4. The image reading device according to claim 1, wherein the image reading device is arranged on the downstream side in the scanning direction with the positional deviation of each of the rear row line image sensors by the dimension tolerance in the sub-scanning direction. 5. A rear row line image sensor located on the most downstream side in the sub-scanning direction among the rear row line image sensors is used as a reference line image sensor, and a read pixel row of the reference line image sensor is the virtual common read line. The image reading device according to any one of claims 1 to 4, which is arranged above.