JPH0377066B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multicolor image recording apparatus, and more particularly to an image recording device having a plurality of recording sections and performing reciprocating scanning recording.

An effective means of improving the recording speed of recording devices such as inkjet printers and thermal transfer printers is to reciprocate a carriage on which multiple recording heads of different recording colors are mounted, and to record images even during the backward movement. A reciprocating scanning recording method is considered.
According to this recording method, not only is it possible to improve the recording speed, but also because the carriage speed is the same in both directions, vibrations during carriage return are prevented.
It is also believed that there is an advantage that the speed control of the carriage drive motor becomes simple. However, if the above-mentioned printing method is applied to a conventional device that prints in parallel with print heads of different colors in the main scanning direction, that is, the direction in which the carriage reciprocates, the ink will change as the scanning direction is reversed. Recording is performed in which the order of overlapping is reversed. For example, as shown in Figure 1a, yellow, magenta, cyan, black (hereinafter referred to as Y, M,
When recording in the order of BK, C, BK) during forward movement, recording is performed in the reverse order of BK, C, M, Y during backward movement, as shown in Figure 1b, during backward movement. As a result, there is a problem in that the recorded color, which should originally be the same, becomes different in tone between the forward movement and the forward movement. That is, as shown in FIG. 2a, the recording paper 1 is
If ink is layered in the order of Y, M, and C on the top, as shown in Figure 2b, the ink will overlap in the order of C, M, and Y during the return trip, so C will be emphasized on the forward trip and C will be emphasized on the return trip. Y will be emphasized, and a color survey will appear in the sub-scanning direction (paper feeding direction), making it very difficult to see.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and improve the image quality of a multicolor image recording apparatus that has a plurality of recording sections and performs back-and-forth scanning recording.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 3 shows an example of the configuration of a multi-nozzle inkjet color printer according to the present invention, where 1 is a recording sheet, 2 is a paper feed roller that feeds the recording sheet 1 in the direction of arrow Y (sub-scanning direction), and 3 is a paper sheet. Paper feed pulse motors 4 and 5 that drive feed roller 2
is a paper guide roller that forms the recording plane.

6 is a carriage on which seven multi-nozzle inkjet heads 7Y to 8BK, which will be described later, are mounted;
Driven by a carriage feed pulse motor 10 via a timing belt 9, a guide rail 11
along arrow R direction and L direction (main scanning direction)
It moves back and forth. 12 and 13 are left end and right end carriage position sensors, which generate predetermined detection signals when the carriage 6 comes to the left end or right end home position. 14 is each head 7Y~8
Ink supply pipe that supplies ink for each BK, 1
5Y, 15M, 15C and 15BK are ink tanks of Y, M, C and BK colors, respectively, and communicate with the heads 7Y to 8BK via pipes 14. 16 is a flexible printed wiring board that supplies drive pulses to each nozzle in each head 7Y to 8BK.

7Y, 7M, 7C and 7BK are multi-nozzle inkjet heads for yellow, magenta, cyan and black, respectively;
M, 8C and 8BK are also multi-nozzle inkjet heads for magenta, cyan and black, respectively. Each of these heads has 8
It has 128 nozzles arranged in a straight line in the direction of the arrow Y at intervals (pitch) of nozzles/mm, and each color ink is directed toward the recording paper 1 by driving pulses supplied via each flexible printed wiring board 16. Discharge. This ink is ejected by, for example, a bubble jet method in which a heating element is embedded in the nozzle and ink droplets are ejected using a valve (bubble) generated by heat generated by a pressure pulse.

As shown, the heads are arranged along the main scanning direction in the order of 8BK, 8C, 8M, 7Y, 7M, 7C, and 7BK from the right side of the drawing toward arrow L.
That is, the yellow recording head 7Y, which is a reciprocating common head, is the center, and the forward recording heads 7M, 7C, and 7BK are connected to the backward recording heads 8M, 8C, and 8.
BK and BK are arranged so as to be point symmetrical with respect to the ink color. When the carriage 6 moves forward in the direction of the arrow R, the reciprocating common head 7Y and the forward moving heads 7M, 7C, indicated by diagonal lines on the left side of FIG.
7BK only, and in synchronization with the switching of the scanning direction of the carriage 6, the driving of the above-mentioned forward head and backward movement head is switched, and during the backward movement when the carriage 6 moves in the direction of arrow L, the movement shown in Fig. 4 is performed. The reciprocating common head 7Y and the reciprocating head 8M are indicated by diagonal lines on the right.
A color image is recorded on the recording paper 1 by driving only 8C and 8BK.

In this way, a forward moving head and a backward moving head are provided separately, and both heads are arranged point-symmetrically with respect to the ink color, and both heads are switched and used according to the switching of the scanning direction of the reciprocating scan. Therefore, the coloring order is the same during reciprocating movement, and disturbances in color tone due to differences in reciprocating movement can be prevented.

FIG. 5 shows an example of the main part configuration of the control circuit of the color printer shown in FIG. 3, and FIG. 6 shows each color page memory (image memory) 31Y, 31M, 31C shown in FIG.
An example of address assignment for 31BK and 31BK is shown below. Here, for example, use A4 size recording paper in portrait orientation,
Assuming that the page is recorded at a density of 8 dots/mm in both the vertical and horizontal directions, the address assignment of the page memory shown in Figure 6 is as shown in the figure, with one address per dot for 1680 dots/210 mm in the horizontal direction. (column address) is assigned from C1 to C.
1680, and one address (line address) is assigned to 128 dots corresponding to 128 nozzles in the recording head for 2576 dots/297 mm in the vertical direction, from l1 to l20.
The allocation will be up to. Note that the line address is displayed at the top and the column address is displayed at the bottom. Also, since the 20th line has a total of 2560 dots, the remaining 16 dots/2 mm are left as margins at the top and bottom of the recording paper.

Next, the control circuit of FIG. 5 will be explained with reference to FIG. 6. Here, 32Y, 32M, 32C and 32BK are each color page memory 31Y, 31C,
This is a column address pointer for specifying column addresses of 31M and 31BK, and here a ring counter that counts from 0001 to 1680 is used. 33 is a line address pointer for simultaneously specifying the line address of each memory. 34Y, 34M, 34C and 34
BK is a head driver, and each page memory 3
According to the dot signals successively output from 1Y, 31C, 31M and 31BK, each recording head 7Y,
M, 7C, 7BK, 8M, 8C and 8BK
Drives 128 inkjet nozzles. 35
3 is a carriage feed motor driver that drives the carriage feed pulse motor 10, 36 is a paper feed motor driver that drives the paper feed pulse motor 3, and 37 is a microprocessor (control computer) that controls each of the above-mentioned blocks. be. Further, 38 is a head switching signal, which is sent from the microprocessor 37 to the head drivers 34M, 3.
It is supplied to 4C and 34BK to select and switch the drive head.

Next, the recording process of the recording method of the present invention will be explained with reference also to FIG. First, move the carriage 6 to the left
and stops at the position where the left end position sensor 12 issues a detection signal (left home position). At this time, the central recording head 7Y is at the leftmost end of the recording range as shown on the left side of FIG. 4, and this position corresponds to column address C0001. Column address pointers 32Y, 32M, 32C and 32
BK is preset to 0001, 1600, 1520 and 1440, respectively, and line address pointer 33 is preset to 01. A prohibition signal is supplied to the remaining head drivers 34M, 34C, and 34BK other than driver 34Y to stop their operations. Furthermore, in response to the signal from the position sensor 12, the microprocessor 37 supplies a head switching signal 38 to the head drivers 34M, 34C, and 34BK, and disconnects only the lines to the backward-only recording heads 8M, 8C, and 8BK. put.

In this state, each page memory 31Y, 3
When the read signal 39 is supplied to 1M, 31C and 31BK, each page memory 31Y, 31M, 3
1C and 31BK each address l01C0001,
Dot data is read from l01C1680, l01C1600, and l01C1520, but since the operation of all the heads except head driver 34Y is stopped, only recording head 7Y is driven, and yellow dots corresponding to the dot data are recorded on recording paper 1. . Then,
Column address pointer 32Y, 32M, 32C
and advances the contents of 32BK in the forward direction, and supplies a drive signal to the carriage feed motor driver 35 to turn the carriage drive pulse motor 10 into 1
The carriage 6 is rotated by the amount of the pulse, and the carriage 6 is driven in the direction of the arrow R by 1 pitch, that is, 1/8 mm. Here, the readout signal 39 is again supplied to each page memory 31Y, 31M, 31C, and 31BK, and the recording head 7Y is driven. page memory 31Y l01C002
A yellow dot corresponding to the dot data of the address is recorded on a recording paper 1.

While repeating these operations, the carriage 6 is moved in the direction of arrow R, starting from column address C0001 of line address l01 of page memory 31Y.
Record dot data up to C0080. As a result, yellow dots are recorded on the recording paper 1 with a width of 16 mm in the vertical direction. Next, the head driver 34M
The inhibition signal to each page memory 31Y,
Read signal 39 to 31M, 31C and 31BK
When the page memory 3 is supplied to the recording head 7Y,
Dot data of address l01C081 of 1Y is supplied,
Further, the dot data at address l01C001 of the page memory 31M is supplied to the recording head 7M. As a result, magenta M ink is printed in a stacked manner on yellow ink Y on the recording paper 1, as shown in FIG. 2a.

Next, column address pointers 32Y, 32
The contents of M, 32C, and 32BK are advanced in the forward direction, and the carriage 6 is moved by one pitch in the R direction, and the readout signal 3 is sent to each page memory again.
9 and drives the recording heads 7Y and 7M to respectively print yellow dots corresponding to the dot data at address l01C082 of the page memory 31Y and magenta dots according to the dot data at address l01C002 of the page memory 31M on the recording paper 1. to be recorded. While repeating these operations, the carriage 6 is moved in the direction of arrow R, and after recording dot data up to column address C160 of line address l01 of page memory 31Y, head driver 34C
Release the prohibition signal to each page memory 34Y~
When the read signal 39 is supplied to the 31BK, the address l01C001 of the page memory 31C is stored in the recording head 7C.
dot data is supplied. Furthermore, when dot data up to column address C240 of line address l01 of page memory 31Y is recorded, if the inhibit signal to head driver 34BK is canceled, all inhibit signals are canceled, and recording heads 7Y and 7M are , 7C and 7BK are all driven.

While repeating the above-mentioned operations, the carriage 6 is moved in the direction of arrow R, and the page memory 31Y is moved.
Immediately after recording the dot data of column address C1680 of line address l01, an inhibit signal is supplied to the yellow head driver 34Y to stop its operation. In this way, each page memory 31
Column address for M, 31C and 31BK
The corresponding head drivers 34M, 34C and 34 at the timing of recording C1680 dot data.
A prohibition signal is supplied to BK to sequentially stop its operation, and dot data from column addresses C0001 to C1680 of line address l01 of each page memory is recorded.

As a result, yellow dots, magenta dots, cyan dots, and black dots are overprinted on the recording paper 1 in the order of 16 mm in the vertical direction (see FIG. 2a). Next, the carriage 6 is moved in the left direction L and returned, and when the right end position sensor 13 detects the right end position of the carriage 6, a predetermined drive pulse is supplied to the paper feed driver 36 to rotate the paper feed pulse motor 3. As shown in FIG. 3 or 4, the recording paper 1 is moved 16 mm in the direction of arrow Y. However, the position of the carriage 6 when the central recording head 7Y records the dot data of column address C1680 is the right end start position of the backward stroke of this carriage 6,
This is assumed to be detected by the right end position sensor 13.

Next, column address pointers 32Y, 32
M, 32C and 32BK each 1680,
0080, 0160 and 0240, and the line address pointer 33 is preset to 02. The remaining head drivers 34M except the driver 34Y,
A prohibition signal is supplied to 34C and 34BK to stop their operation. Further, in response to the signal from the position sensor 13, the microprocessor 37 sends a head switching signal 38 to the drivers 34M, 34C and 3.
4BK, recording head 7M, 7 for forward movement only
Only the lines to C and 7BK are disconnected, and the lines to backward recording heads 8M, 8C and 8BK are connected.

In this state, each page memory 31Y, 31M,
When the read signal 39 is supplied to 31C and 31BK, the respective addresses l02C1680, 31Y, 31M, 31C, and 31BK are read.
Dot data is read from l02C0080, l02C0160, and l02C0240, but since the operation of all the heads except the head driver 34Y is stopped, only the recording head 7Y is driven, and yellow dots corresponding to the dot data are recorded on the recording paper 1. . Then,
Column address pointers 32Y, 32M, 32C
Then, in synchronization with advancing the contents of 32BK in the opposite direction, the carriage 6 is moved in the direction of arrow L to perform a recording operation.

In this way, each column address pointer 3
Each time 2M, 32C and 32BK change from 1 to 1680, the corresponding head drivers 34M, 34
The inhibit signal to C and 34BK is released, and all recording heads 7Y, 8M, 8C and 8BK to be driven during the backward movement are driven. At that time, each recording head 7
The color arrangement order of Y, 8M, 8C and 8BK is as follows:
Since the colors are yellow, magenta, cyan, and black, which are the same as those of the recording heads 7Y, 7M, 7C, and 7BK during forward movement in the direction of movement of the carriage 6, the colors are printed in an overlapping manner in the order in which they are arranged. That is, yellow dots, magenta dots, cyan dots,
Since the black dots are overprinted in the order of the black dots, there is no change in color tone between back and forth scans, resulting in an image quality that is extremely faithful to the original.

The subsequent backward recording operation synchronizes with advancing the contents of column address points 32Y, 32M, 32C, and 32BK in the opposite direction.
The head drivers 34Y, 34M, and 34C are moved in the same manner as in the forward movement except for moving the head in the direction of the arrow L, and each head driver 34Y, 34M, 34C is
and 34BK, and the dot data from column addresses C1680 to C0001 of line address l02 of each page memory is recorded. Next, the carriage 6 is moved in the right direction R, and when the left end position sensor 12 detects the left end position of the carriage 6, the paper feed pulse motor 3 is rotated to move the recording paper 1 16 mm in the direction of arrow Y, and the next forward movement is started. Move on to recording operation. The above reciprocating recording operation is repeated to complete recording up to line address l20.

FIG. 7 shows another example of the configuration of a multi-nozzle inkjet color printer according to the present invention, and FIG.
The figure shows an example of the control circuit of the color printer shown in FIG. In this embodiment, as shown in the figure, a reciprocating recording head is not used, but recording heads 7Y and 7 are used.
M, 7C and 7BK can be used as heads exclusively for forward movement, and recording heads 8Y, 8M, 8C and 8
BK is used as a head exclusively for double movement. Also,
Each head is indicated by an arrow L from the right side of the drawing as shown in Figure 7.
Towards 8BK, 8C, 8M, 8Y, 7Y, 7
M, 7C and 7BK will be installed in that order. That is, when recording an image, the forward recording heads 7M, 7C, 7BK and the backward recording heads 8M, 8
C and 8BK are arranged so as to be point symmetrical with respect to their ejected ink colors.

During forward recording in which the carriage 6 moves in the direction of arrow R, only the forward movement heads 7Y, 7M, 7C, and 7BK indicated by diagonal lines on the left side of FIG. 9 are driven to record, and the carriage 6 moves in the direction of arrow L. During the backward motion recording, only the backward motion heads 8Y, 8M, 8C, and 8BK shown by diagonal lines on the right side of FIG. 9 are driven to record.

Therefore, in the control circuit of this example, as shown in FIG. 8, there are two central recording heads, 7Y and 8Y, driven by the head driver 34Y, and the head switching signal 38 is also applied to the head driver 34Y.
is supplied. Other configurations are shown in Figures 3 and 5.
Since it is almost the same as the first embodiment shown in the figure, detailed explanation thereof will be omitted. Therefore, the coloring order is exactly the same during reciprocating movement, and no difference in color tone occurs due to the difference in reciprocating movement.

As explained above, according to the embodiment of the present invention, when the recording operation is performed not only during the forward movement of the recording head but also during the backward movement, there is no difference in color tone due to the difference between the forward path and the backward path, and a good result is obtained. image quality can be obtained.

In particular, when a conventional device performs back-and-forth recording, a noticeable difference in color tone occurs in the main scanning direction, resulting in mottling, making it impossible to put it to practical use.However, according to the embodiment of the present invention, such inconveniences can be completely eliminated. Therefore, even in multi-color recording, the recording operation can be performed not only when the recording head moves forward, but also when it moves backward, and it is possible to improve the recording speed of color motion pictures.
In addition, as a result of making such reciprocating recording possible, there is no need for the carriage to go back at high speed as in the conventional one-way recording method, the configuration of the carriage feed motor driver is simplified, and the carriage can go back at high speed. The recoil of the casing that occurs when moving the camera is also eliminated.

Regarding sub-scanning, in the embodiment of the present invention, the recording paper 1 is moved in the Y direction, but it is also possible to fix the recording paper and move the carriage in the opposite direction of the arrow Y, like an X-Y plotter. You can also do it. Further, the symmetrical recording device is not limited to the inkjet printer as in the embodiment, but is of course suitable for thermal transfer printers and the like.

As described above, according to the present invention, by making the order of coloring constant during the forward and backward movements of a multicolor recording device that performs reciprocating scanning recording, it is possible to stabilize the color tone, and moreover, the image data can be By prohibiting recording regardless of the supply of image data from the supply means, if unnecessary image data that should not originally be recorded is supplied from the supply means, for example, if the image is outside the area where the image should be recorded. However, even if image data is supplied, it is possible to prevent the image data from being recorded, thereby improving image quality.

[Brief explanation of drawings]

Figures 1a and b are state diagrams showing an example of the recording process by a conventional recording device during forward recording and backward recording, respectively, and Figures 2a and b are similar to Figures 1a and b. FIG. 3 is a perspective view showing an example of the printer according to the present invention, FIG. 4 is a state diagram showing the recording process by the printer of FIG. 3, and FIG. FIG. 3 is a block diagram showing an example of the configuration of the control circuit of the printer, FIG. 6 is a diagram showing an example of the address assignment of the page memory in FIG. 5, and FIG. 7 is a diagram showing another embodiment of the printer according to the present invention. 8 is a block diagram showing a configuration example of a control circuit of the printer shown in FIG. 7, and FIG. 9 is a state diagram showing a recording process by the printer shown in FIG. 7. 1... Recording paper, 2... Paper feed roller, 3...
Paper feed pulse motor, 4, 5... Paper guide roller, 6... Carriage, 7Y, 7M, 7C, 7
BK, 8Y, 8M, 8C, 8BK... Ink jet head, 9... Timing belt, 10...
Carriage feed pulse motor, 11...Guide rail, 12...Left end carriage position sensor, 13
...Right end carriage position sensor, 14...Ink supply pipe, 15Y, 15M, 15C, 15BK
...Ink tank, 16...Flexible printed wiring board, 31Y, 31M, 31C, 31BK...Page memory, 32Y, 32M, 32C, 32BK
...Column address pointer (ring counter),
33...Line address pointer, 34Y, 34
M, 34C, 34BK...Head driver, 35
... Carriage feed motor driver, 36 ... Paper feed motor driver, 37 ... Microprocessor, 38 ... Head switching signal, 39 ... Read signal.

Claims (1)

[Claims] 1. A first recording section for recording a first color during forward movement, and a second recording section for recording a second color different from the first color during forward movement. A third recording section for recording the second color during backward movement, and a fourth recording section for recording the first color during backward movement are arranged in the main scanning direction. a second recording unit supplied to the second recording unit during forward movement;
The image data of the first color is delayed by a first period corresponding to the distance between the first recording section and the second recording section, and the image data of the first color is transferred to the first recording section. and a second period corresponding to the distance between the third recording section and the fourth recording section for the second color image data supplied to the third recording section during the backward movement. supply means for delaying and supplying the first image data to the fourth recording unit; and prohibiting recording operation by the first recording unit for the first period at the start of the forward movement, and supplying the first image data to the fourth recording unit at the end of the forward movement; During the first period, the recording operation by the second recording unit is prohibited, at the start of the backward movement, the recording operation by the fourth recording unit is prohibited, and at the end of the backward movement, the second period, a signal generating means for generating a prohibition signal for prohibiting a recording operation by a third recording section; and based on the prohibition signal from the signal generating means, the recording operation is not performed regardless of the supply of image data by the supplying means. An image recording apparatus comprising: a control means for controlling each recording section of the recording means.