JP2001334648A - Composite ink jet printer and its controlling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite ink jet printer in which a high quality print can be realized by eliminating a blur itself occurring when an image is read out at a scanner section due to vibration incident to scanning of an ink carriage or carriage of a sheet. SOLUTION: The composite ink jet printer comprises a reading means, a printing means, a sheet feeding/carrying means, means for temporarily storing image data read out by the reading means before delivering to the print means, and means for controlling operation of each means wherein the control means controls the operational timing of each means to start scanning of the print unit at least after the image reading unit makes a transition from scanning state to stopping state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer, and more particularly, to a combined ink jet printer in which image reading means and printing means are integrated.

[0002]

2. Description of the Related Art In recent years, an ink jet printer which has been conventionally used as a single printing means simply functions as a printer by being equipped with an image reading means (scanner section) or a modem. In addition, a multifunction peripheral having a copy function and a FAX function has been developed. The scanner unit is configured to read an image every several lines from the document and store the image in the memory of the control unit, instead of reading the image from the document in one scan as in a normal copying machine. .

Since this memory has a capacity of only a few lines, an image of several lines is normally read, and then data is transferred to a printing unit via the memory. Is printed for each line,
One image is formed by repeating one cycle of starting reading of the next image again when the memory has free space, a plurality of times. In other words, in order to form one image, not only the scanner unit but also the ink carriage of the printing unit reciprocates a plurality of times.

As described above, the method of reading a manuscript every time several lines are printed does not pose a serious problem on a network in which an ink jet printer alone and another medium (such as a computer) are connected. That is, according to this method, data is transmitted and received and printing is performed in a state where the data transfer speed, the printing speed, and the capacity of the memory are known in advance on the network. Therefore, the frequency of occurrence of a defect at the time of reading and printing an image is low, and there is no loss of transmitted data.

However, in the above-described composite type ink jet printer, after the above-described one cycle is completed, the next cycle is performed, that is, data of a portion corresponding to a seam at the time of scan-stop at the time of document reading is stored. This is a very important point for realizing high quality printing.

To explain this point in detail, there is no problem in printing for several lines in one cycle since the reading is continuously performed by the scanner unit.
After the completion of one cycle, at the seam where the next one cycle is executed, the image reading operation itself by the scanner unit is interrupted. Therefore, even at the time of printing, the data at the time of the interruption (the seam at the time of scan-stop) is also used. A slight shift between before and after greatly reduces the quality of the finally obtained image.

In particular, at the seam at the time of the above-mentioned scan-stop, the vibration of the printing section and the vibration at the time of transporting the paper, which occur when the ink carriage scans the printing section,
This causes blurring during the scan-stop alignment in the scanner unit and the reading operation of the scanner unit.

As a result, noticeable blurring occurs in data read by the scanner unit. When the image printed by the printing unit is monochrome, the shift on the image due to the blurring is a black-and-white shift, and thus it is difficult to visually recognize the shift as a large shift. However, in the case of a color image, a change in hue is also recognized in addition to a mere shift, so that the shift is particularly greatly recognized, and there is a problem that the influence of blur is remarkably determined.

As a technique aimed at solving such a problem, there is a technique disclosed in Japanese Patent Application Laid-Open No. 7-323613. This technique proposes a method of correcting the above-described hue shift due to blurring using image processing, specifically, using a correction table.

[0010]

However, in the technique disclosed in Japanese Patent Application Laid-Open No. Hei 7-323613, since the processing such as error diffusion performed in the image processing is complicated, the structure and mechanism of the composite type ink jet printer are reduced. In addition to the complication, it does not prevent the occurrence of blur itself, and therefore, there is a problem that as a result of the image processing performed by the apparatus, a print desired by the user cannot always be reproduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a multi-type ink jet printer, in which an image is read by a scanner unit due to vibration generated during scanning of an ink carriage or conveyance of a sheet. An object of the present invention is to realize high-quality printing by eliminating the blur itself that sometimes occurs.

[0012]

According to the present invention, means for solving the above-mentioned problems are constituted as follows.

(1) A reading unit having an image reading unit capable of scanning two-dimensionally and repeating scanning and stopping for each of a plurality of lines, and capable of scanning substantially one-dimensionally and printing each line on a conveyed sheet A printing unit having a printing unit for performing printing, a paper feeding and transporting unit having a paper transport roller for transporting paper to the printing unit, and temporarily storing image data read by the reading unit and outputting the image data to the printing unit. In a combined inkjet printer having a storage unit and a control unit for controlling the operation of each of the units, the control unit is configured to control the operation of the printing unit at least after the time when the image reading unit changes from the scanning state to the stop state. The timing of the operation of each means is controlled so as to start scanning.

In this configuration, since the printing unit is caused to scan after the time when the scanning of the image reading unit is completed and stopped, the influence of blurring can be reliably avoided, and a high-quality image can be obtained.

(2) The control means controls the sheet feeding and feeding so as to start the conveyance of the sheet at least after the time when the image reading unit is changed from the scanning state to the stop state.
It is characterized in that the timing for operating the transfer means is controlled.

In this configuration, the occurrence of blur can be more reliably prevented by considering the timing at which the paper is conveyed.

[0017] A jet printer.

(3) The control means controls an operation timing of each of the means so that scanning of the image reading unit is performed while the printing unit is stopped. I do.

In this configuration, since the scanning of the image reading unit is performed while the ink carriage is stopped, blurring during image reading can be more effectively eliminated.

(4) The control means controls the operation timing of each means so that the image reading unit is stopped even when the printing unit in the scanning state is accelerated and decelerated. The inkjet printer according to claim 3, wherein

In this configuration, the image reading unit is stopped even when the printing unit is accelerating and decelerating, so that blurring during image reading can be eliminated even more effectively.

(5) The image printed by the printing means is a color image.

In this configuration, since the occurrence of blur itself is avoided, the quality of a color image can be significantly improved.

(6) After the image is read by the image reading unit capable of two-dimensional scanning, the read image data is transferred to the storage means and temporarily stored therein. In a method for controlling an ink jet printer in which data is transferred and the printing unit is operated based on the image data to print an image on a sheet, at least the time during which the image reading unit is in a stopped state from a scanning state. Thereafter, the scanning of the printing unit is started.

In this configuration, since the printing unit is caused to scan after the time when the scanning of the image reading unit is completed and stopped, it is possible to surely avoid the influence of the blur and provide a higher-quality image. it can.

(7) When the paper on which the image is to be printed is conveyed at regular intervals, the movement of the paper is started at least after the time when the image reading unit stops from the scanning state to the stop state. And

In this configuration, the timing of paper transport is taken into consideration, so that the occurrence of blur can be avoided more reliably.

[0028]

FIG. 1 shows the configuration of a composite ink jet printer (hereinafter referred to as the present printer) 1 according to an embodiment of the present invention. As shown in FIG. 1, the printer 1 includes a scanner unit (reading unit) 2 and a printing unit (printing unit).
3, a paper feed cassette 4, a paper discharge tray 5, a paper transport roller 6, and a paper transport path 7.

The scanner section 2 includes an optical unit (image reading unit) 8, a document cover 9, a platen glass 10, and the like. A document is placed on the platen glass 10 and the optical unit 8 is scanned. Read (scan) the image. The optical unit 8 includes the light source 1
1, first mirror 12, second mirror 13, third mirror 1
4. An imaging lens 15 and a CCD 16 are provided.

The printing section 3 includes an ink carriage (printing unit) 17 and a platen 18 opposed thereto. The ink carriage 17 includes a plurality of ink heads 19.
In order to make scanning of the ink carriage 17 smooth,
An ink carriage holding shaft (not shown) for slidably supporting the ink carriage 17 is provided. The paper transport path 7 is provided between the ink carriage 17 and the platen 18.

The paper transport path 7 is provided between the paper feed cassette 4 and the paper discharge tray 5, and a paper transport roller 6 is provided in the middle. The paper cassette 4 contains
A pickup roller 21 is provided, and a sheet feeding / conveying unit (sheet feeding / conveying means) is provided by the sheet feeding cassette 4, the pickup roller 21, the sheet conveying roller 6, the sheet feeding roller 22 #, and the like.
23 are configured.

As shown in FIG. 2, the printer 1 has a control unit (Central Processing Unit) having a CPU (Central Processing Unit) for controlling the above-described scanner unit 2, printing unit 3, and paper feed / conveyance unit 23. (Control means) 24. In the present embodiment, when a print request is made from a personal computer or the like serving as a host, the control unit 24 first outputs control information to the scanner unit 2 and causes the scanner unit 2 to execute an image reading operation. .

On the other hand, one sheet of paper P is transported from the paper feed cassette 4 to the paper transport path 7 by the pickup roller 21. The paper P passes through the paper transport path 7 by the paper transport roller 6 and the paper feed roller 22 and reaches the position of the ink carriage 17. At this time, the PS roller 25 operated by a command from the control unit 24 adjusts the leading edge of the image data and the leading edge of the paper P so as to match.

The image data read by the scanner unit 2 is temporarily stored in a memory (storage means) 27 provided in the control unit 24, and thereafter output to the printing unit 3 to correspond to the image data. The paper is conveyed by the amount of printing. The ink carriage 17 in the printing unit 3 discharges necessary ink to record (print) an image on the paper P in accordance with the image data. At the time of this recording, the paper P
, The conveyance of the paper P is stopped until the ink carriage 17 completes the scanning of one line (one direction).

When the scanning of one line is completed, the paper is conveyed by an amount corresponding to the plurality of ink nozzles of the ink head 19. This cycle is repeated, and an image is written on the paper P by ink. The paper P on which the writing of the image has been completed passes through an ink drying unit (not shown),
The paper is discharged onto the paper discharge tray 5 and provided to the user as printed matter.

In the printer 1, the scanner unit 2 reads an image from a document every several lines,
In the memory 27, and in the printing unit 3, the memory 2
7, one cycle of printing for each line is repeated.

The one cycle will be described step by step.
First, (a) an original is read for several lines by the scanner unit 2 and stored in a memory. (B) With the reading of the document temporarily stopped, printing is performed line by line by the printing unit 3. Then, (c) printing for several lines stored in the memory is completed. As a result, an empty space is generated in the memory capacity, and the original is read again by the scanner unit 2 (the above (a) is repeated). By repeating this one cycle, one image read from one document is printed.

Here, the optical unit 8 of the scanner unit 2
Reads an image two-dimensionally from a document placed on the platen glass 10. Therefore, the optical unit 8 can scan in both the main scanning direction and the sub-scanning direction. Specifically, as shown in FIG. 3A, the optical unit 8 includes a main scanning direction ± V direction and a sub scanning direction L direction on the rear side of the platen glass 10 on which the original is placed. Scanning is possible.

Therefore, assuming that the position of the optical unit 8 is represented by the coordinates (V, L), the position before the start of the document reading is (0, 0). Then, the movement of one cycle of image reading in the optical unit 8 starts from (0, 0) and then (V _max, L1), as shown in FIG.
(Vmax _, L3), (0, L4), ( _-Vmax, L2 ~
(L), (L2, 0), and move in a substantially circular manner. However, L1 <L2 <L
3 <L4. Then, the same movement is repeated, and an image is read from the surface of the document.

On the other hand, the ink carriage 17 of the printing unit 3
Performs almost one-dimensional movement (linear movement), but prints one-dimensionally on the paper conveyed at a constant interval. To 2
A two-dimensional image is printed. Specifically, FIG.
As shown in FIGS. 4A and 4B and FIG. 4, the ink carriage 17 can scan the paper P conveyed at regular intervals in the lower paper conveyance path 7 only in a direction perpendicular to the paper P. ing. Therefore, when viewed from the side where the sheet P is being conveyed (that is, from the sheet discharge tray 5 side in FIG. 1),
The right side is the right scanning direction, and the left side is the left scanning direction.

The ink carriage 17 itself is scanned right / left in accordance with the image data, and
Although printing is performed on the upper side, since the paper P itself is moving to the paper discharge tray 5 side, the movement in one cycle is as shown in FIG.
As shown in (1), when the start position of the ink carriage 17 is set to 0, a substantially waveform movement having a height up to the maximum value in the right and left scanning directions is performed based on the 0 position. Then, the same movement is repeated, and an image is printed on the surface of the sheet.

Here, the timing of the scanning of the optical unit 8 and the scanning of the ink carriage 17 will be described. Specifically, in the above one cycle, the optical unit 8 is scanned and the CCD 16 of the optical unit 8 is scanned.
Is transferred to the memory 27, the data is transferred from the memory 27 to the ink carriage 17, and the paper P is transported while the ink carriage 17 is scanned.

Therefore, in the timing control in one cycle, each of [scan of optical unit], [transfer of data from CCD to memory], [transfer of data from memory to carriage], [scan of carriage], and [paper transport] The process must be properly timed.

The present invention will be described for the timing control in comparison with the prior art. FIG. 5 shows the timing of the conventional reading / printing process as a comparative reference example, and FIG. 6 shows the timing of the reading / printing process of the present invention.

First, a conventional image reading / printing operation will be described with reference to FIG. First, the leading end of the printing position of the sheet P conveyed from the sheet cassette must reach a position where the ink carriage is located. Therefore, in the process chart of [paper conveyance], a waveform indicating paper conveyance appears for a certain period of time from the start.

Next, the image information is read from the original placed on the scanner unit. As described above, the image reading operation is performed so that one cycle is performed every several lines. In the process chart of [Scan], a waveform for reading several lines appears. Note that FIG.
(A), (B) and as shown in FIG.
Is movable in the ± V direction, and accordingly, the waveform also appears vertically from the reference position.

Since the read data is temporarily transferred to the memory, the process chart of [Transfer of Data from CCD to Memory] has a slight delay from the scanning waveform appearing in the chart of [Optical Unit Scan]. As a result, a waveform indicating data transfer appears.

After that, printing is performed by the ink carriage, but since the ink carriage can print only one line at a time, data for each line is transferred from the memory to the ink carriage. become.

Therefore, the waveform indicating the data transfer of one line is slightly delayed from the data transfer waveform shown in the chart of [Transfer of Data from CCD to Memory] in the chart of [Transfer of Data from Memory to Carriage]. Appears in the process chart. In the present printer 1, since reading is performed every four lines, four waveforms indicating data transfer for one line appear.

Then, based on the transferred data, the ink carriage scans right or left from the 0 position and prints on the paper. Therefore, the process chart of [carriage scanning] includes A waveform indicating the scanning of appears. However, as described above, the ink carriage is 0
Since it is scanned right or left from the position and printed on the paper, if one line is scanned rightward first, the next one line is scanned leftward.
(Refer to the movement of the ink carriage in FIG. 3). On the chart, waveforms for one line appear alternately in the vertical direction.

When printing for four lines is completed,
Again, the paper is transported by four lines, and the next one cycle is repeated. Therefore, a waveform indicating the transport of the paper appears in the process chart of [paper transport]. In addition,
The waveforms of the four lines are shorter than the waveforms at the start.

In the conventional timing control described above, between each cycle, at the seam at the time of scan-stop, the vibration of the printing unit and the vibration at the time of paper conveyance that occur during scanning of the ink carriage in the printing unit are: Position blur occurs during alignment or reading operation. As a result, noticeable blurring occurs in data read by the scanner unit. In particular, in the case of a color image, the effect of the blur is recognized not only as a mere shift on the image but also as a hue shift, so that the image quality is greatly reduced.

Therefore, in the present printer 1, as shown in FIG. 6, the time when the waveform appearing in the process chart of [optical unit scanning] disappears, that is, the scanner unit 2
After the time when the image reading performed in is completed,
The control unit 24 causes the printing unit 3 to execute printing.
Control the operations of the optical unit 8 and the printing unit 3. As a result, it is possible to eliminate the influence of the blur and provide a higher quality image.

More specifically, first, the paper P is transported from the paper feed cassette 4 and the leading end of the printing position on the paper P reaches a certain position of the ink carriage 17 ([paper transport]). A waveform indicating the conveyance of the paper P appears for a certain time from the start). Thereafter, image information is read from the document placed on the scanner unit 2 (a waveform for reading several lines appears in the process chart of [scanning of the optical unit]), and the read data is temporarily transferred to the memory ([ The process chart of [Data Transfer from CCD to Memory]) is the same as that of the above-described conventional method.

Thereafter, the ink carriage 17 is read from the memory.
The ink carriage 17 is scanned based on the data, but the scanning of the ink carriage 17 is not performed while the optical unit 8 is scanning. Therefore, the waveform that shows the scanning for each line, which appears in the process chart of [carriage scanning]
The waveform appears at least after the time when the waveform appearing in the chart of [optical unit scanning] disappears (see point a).

As described above, in the printer 1, the timing between the scanning cycles (scan-stop) in reading the original is adjusted to the time when the vibration of the ink carriage 17 in the printing unit 3 is reduced. As a result, blurring during document reading can be effectively eliminated to achieve high-quality printing, and the configuration of the printer can be simplified (without complication).

By the way, as a configuration that causes blurring when reading an original, not only the ink carriage 17 but also a paper transport mechanism (the paper transport roller 6 in FIG. 1).

Therefore, by considering the conveyance of the sheet P in the timing between the scanning cycles in reading the original, the occurrence of blur can be more effectively eliminated. More specifically, the timing of the paper feed / transport unit 23 may be controlled so that the transport of the paper P is started at least after the time when the scanner unit 2 changes from the scan state to the stop state.

It is preferable that the control unit 24 performs timing control such that scanning of the optical unit 8 is performed while the ink carriage 17 is stopped. This makes it possible to more effectively eliminate blurring when reading a document.

Further, the control unit 24 controls the time when the ink carriage 17 in the scanning state is accelerated and decelerated.
It is preferable to perform timing control such that the optical unit 8 is stopped. In particular, during acceleration or deceleration, the blur is likely to be large, and thus the timing control can further effectively reduce the blur.

[0061]

The present invention has the following effects.

(1) The timing of the operation of each unit is controlled so that the scanning of the printing unit is started at least after the time when the image reading unit changes from the scanning state to the stop state. , And a high-quality image can be obtained.

(2) Since the conveyance of the sheet is started at least after the time when the image reading unit changes from the scanning state to the stop state, the timing of conveying the sheet is considered, and the occurrence of blur is more reliably prevented. can do.

(3) The timing of the operation of each unit is controlled so that the scanning of the image reading unit is performed while the printing unit is stopped. It can be eliminated more effectively.

(4) The operation timing of each means is controlled so that the image reading unit is stopped when the ink carriage in the scanning state is accelerating and decelerating. The problem can be solved even more effectively.

(5) Since the image printed by the printing means is a color image, the occurrence of blur itself is avoided, so that a color image can be formed with much higher quality as compared with the related art. .

(6) Since the scanning of the printing unit is started after the time when the image reading unit is changed from the scanning state to the stop state, the influence of blur is reliably avoided and a higher quality image is provided. can do.

(7) Since the movement of the sheet is started after the time when the image reading unit changes from the scanning state to the stop state, the occurrence of blur can be avoided more reliably.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a composite inkjet printer according to an embodiment of the present invention.

FIG. 2 is a block diagram of the control system.

FIGS. 3A and 3B are graphs showing scanning trajectories of the optical unit.

FIG. 4 is a graph showing a scanning locus of the optical unit on coordinates.

FIG. 5 is a timing chart showing an example of a conventional reading / printing process.

FIG. 6 is a timing chart of a reading / printing process according to the embodiment of the present invention.

[Explanation of symbols]

 1-Composite Inkjet Printer 2-Reading Unit 3-Printing Unit 6-Paper Conveying Path 8-Image Reading Unit 17-Printing Unit 23-Supply / Conveying Unit 24-Control Unit 27-Storage Unit

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Tadaaki Kono 22-22, Nagaikecho, Abeno-ku, Osaka-shi, Osaka F-term (reference) 2C056 EA04 EA07 EA18 EB59 EC11 EC12 EC37 FA10 HA58 2C061 AP04 AQ05 AR01 AS02 HK11 HN15 5C072 AA05 BA19 FB23 MB09 NA08 QA14 SA06 XA04 5C074 AA02 BB16 CC25 CC26 DD11 DD16 EE06 FF15 GG15 GG19 5C079 JA11 JA23 KA12 LA24 MA03 MA11 NA02 PA03

Claims (7)

[Claims] An image reading unit capable of two-dimensionally scanning and repeating scanning and stopping for each of a plurality of lines;
A printing unit having a printing unit capable of scanning substantially one-dimensionally and printing each line on a conveyed sheet, a sheet feeding / conveying unit having a sheet conveying roller for conveying the sheet to the printing unit, Storage means for temporarily storing the image data read by the reading means and outputting the image data to the printing means,
A composite ink jet printer having control means for controlling the operation of each of the means, wherein the control means starts scanning of the printing unit at least after a time when the image reading unit changes from a scanning state to a stop state. A composite ink jet printer characterized in that the timing of the operation of each means is controlled. 2. The image processing apparatus according to claim 1, wherein the control unit is configured to execute at least a time period after the image reading unit changes from a scanning state to a stop state.
2. The ink jet printer according to claim 1, wherein a timing at which the sheet feeding / conveying unit is operated is controlled so as to start conveying the sheet. 3. The apparatus according to claim 1, wherein the control unit controls the operation timing of each of the units so that the image reading unit scans while the printing unit is stopped. The inkjet printer according to claim 1. 4. The apparatus according to claim 1, wherein the control unit controls the operation timing of each unit so that the image reading unit is stopped even when the printing unit in a scanning state is accelerated and decelerated. The inkjet printer according to claim 3, wherein 5. An ink jet printer according to claim 1, wherein the image printed by said printing means is a color image. 6. After an image is read by an image reading unit capable of two-dimensional scanning, the read image data is transferred to a storage means and temporarily stored therein. Is transferred, and based on the image data, the printing unit is operated to print an image on paper. In the control method of the ink jet printer, at least after the time when the image reading unit is in the stopped state from the scanning state And controlling the printing unit to start scanning. 7. When a sheet on which an image is to be printed is conveyed at regular intervals, the movement of the sheet is started at least after the time when the image reading unit stops from the scanning state to the stop state. The method for controlling an ink jet printer according to claim 6.