JP2727035B2 - Print control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a dot matrix
The present invention relates to a print control device for a printer.

[0002]

BACKGROUND OF THE INVENTION Problems to be Solved by the Invention
2. Description of the Related Art In an image recording apparatus such as an ink jet printer, scanning of a recording medium is performed by a print head reciprocating on a recording medium such as a paper sheet or continuously moving along a paper sheet sent to a rotating drum. I do. An image is formed by selectively attaching ink to pixels (pixels) arranged in a matrix of lines (rows) and columns (columns). The image formed by scanning the print head in parallel with the recording medium in this manner may be a graphic or a text. Conventional scanning print heads have one nozzle for each print color. These nozzles are located near the paper sheet.
The print head for each line of this paper sheet
The carriage moves to selectively deposit ink on the pixels and scans the entire image area.

In such a printer, the actual print area must be limited to an image area. Therefore, when an ink jet nozzle hole or a print element of a print head crosses an edge of an image, a function to determine whether the ink head is moving in a direction away from the image area or in an internal direction is required. Become.

When printing the edge of an image with a print head having a large number of nozzle holes, it is considered that electronic control of the print head becomes extremely difficult. Unless all nozzle holes are aligned on a single vertical line, each jet nozzle is fired sequentially and sequentially in line with the image pattern as the head moves from the left toward the right edge of the image is, the head is further from the right edge of the image
Similarly, when leaving to the right,
Control of the injection stop of the nozzle must be performed. In the case of such bidirectional printing, the reverse control must be performed even when the head crosses the left edge of the image.

A common solution to this problem is to assign a value equal to the width over which the head is scanned and blank data, ie, blank data, to portions of the image data stored in the image buffer memory corresponding to both sides of the image. That is.
In this way, when the image data is read from the memory and the head is driven and controlled, image data having a value of zero is automatically sent so that each jet nozzle is properly stopped at the edge of the image. However, since printer heads are typically more than three inches wide, this method requires writing zero value blank data over a very large area of memory. In fact, when printing an image on a standard 8.5 x 11 inch paper with a normal print margin, blank data with a value of zero must be written to more than half of the entire image buffer memory. As a result, the storage capacity of the image buffer memory must be increased by a factor of two or more as compared with the case of storing data of only the image to be printed. This not only causes an increase in cost due to wasted memory capacity, but also significantly reduces the output speed of image printing because extra time is required to write zero-value data to all extra memory areas. There is also the problem of doing so.

Another solution to the above problem is to use a look-up table under software control in ROM to use the number of image data from the image edge as the address of the table and to convert the head control data to the image. There is a method of selectively operating in accordance with this. This method is also expensive and requires special circuitry to calculate the distance from the edge of the image. Further, when the number of jet nozzles in the print head reaches about 100, the software required for image edge print control becomes complicated, and the capacity of the ROM for storing the same becomes extremely large.

Accordingly, an object of the present invention is to provide a print control apparatus having an image edge print control function capable of transmitting image data to a print head without delay at a relatively low cost, requiring a small amount of memory and a small amount of calculation. It is to be.

[0008]

According to the present invention, there is provided a print control apparatus which moves a print head having a plurality of print elements in a predetermined direction on a recording medium, and converts each of the plurality of print elements into image data. , And controls a printer that forms a predetermined image corresponding to the image data on the recording medium, the index marker indicating the center of the movement path of the print head, and the index marker. Position marker means having a plurality of position markers provided along the movement path on both sides of the print head, and detecting the index marker of the position marker means in accordance with the movement of the print head to detect the position of the print head. While calibrating the location information ,
The plurality of position markers of the position marker means are detected, the number of the detected position markers is counted, the position information of the print head is detected, and each of the print elements forms the predetermined image. Position detecting means for generating a signal indicating whether or not the image is at a predetermined position, and receiving the output signal of the position detecting means and sequentially supplying the image data to the print element at the predetermined position. The other print elements are provided with data control means for supplying control data for stopping the printing operation.

[0009]

FIG. 2 shows a plurality (five) of which are spaced apart so that a plurality of non-adjacent lines can be printed simultaneously.
1 is a schematic diagram of a print head 20 having a nozzle 22 of FIG. The head 20 is disposed adjacent to a drum 24 around which a recording medium such as a paper sheet 26 is wound. Drum 24
And as the paper sheet 26 rotates, the head 20
Moving at a constant speed in the direction of the rotation axis, all lines are printed. For each revolution, the head 20 equivalently prints five spaced lines. Therefore, FIG.
For each subsequent rotation, the upper line between the lines printed by the previous rotation is printed, as shown in plan view in FIG. In the embodiment of FIG. 4 described later, printing is performed by reciprocating scanning on a flat recording medium. In these figures, the spacing between the centers of adjacent lines is the reciprocal of the DPI density (dot density per inch), ie, 1 / D
In PI, the interval for two lines is 2 / DPI. In FIG. 3, a broken line indicates the head 20 located at the end of the sheet after the scanning of a series of lines is completed. The head 20 at the same position on the drum 24 ready for scanning the next series of lines is indicated by a solid line. Arrows indicate that the next line group is interlaced with the previously scanned line group. The previous series of lines is all printed. If the drum 24 is rotated to continue printing the subsequent series of lines, all the lines on the sheet 26 are printed.

FIG. 4 shows a print similar to FIGS. 2 and 3.
1 is a schematic diagram of a system. The head 30 has nozzles 32 and prints every other line on a sheet 34.
However, the sheet 34 on the drum does not rotate,
It moves vertically and horizontally with respect to the head 30. Normally, as the sheet 34 advances, the head 30 reciprocates over the surface of the sheet many times. As each group of lines is printed, the head 30 is shifted down the sheet by the length indicated by arrows 36 and 38. This shift amount is
Equal to the width of 5 lines to be printed. Thus, typically, the head 30 stops at the end of each scanning operation, the sheet is shifted, and the head 30 is driven on the sheet in the opposite direction.

In the example of FIG. 4, the same effect of the printing operation as in the method of FIGS. 2 and 3 can be obtained. The letters (A, B, C) on each head indicate the order of the printing operation in alphabetical order.

FIG. 5 is a diagram showing an embodiment of another printing apparatus. The head 50 includes sub heads 51, 52 and 5
3 (represented by numerical values 1, 2 and 3 respectively). Each sub head prints a group of adjacent lines indicated by parentheses on the recording medium sheet 54. Again sheet 5
The scan on 4 is performed in alphabetical order as shown.
Solid arrows on the sheet indicate the scanning direction of the head in the corresponding area.

The sub heads constituting the head 50 include:
The sub heads are provided at the same intervals as the intervals between the areas scanned by the sub heads. During the scanning B period, the sub head 5
The area on the sheet 54 that is printed by
And the area scanned by the sub-head 53 during the period C and the area scanned by the sub-head 53 during the period C, the entire area is printed without gaps by these scans. The head 50 moves ahead by the same length as the three sub head areas for each scanning operation.

In FIG. 5, the configuration of the second embodiment of these subheads is indicated by broken lines as a head 55 including subheads 56, 57 and 58. These subheads print an area having the same width as the subhead of the head 50. However, these subheads are provided apart from each other by the width of four subheads. Scan areas corresponding to these subheads are indicated by dashed alphabets such as A '. The scanning direction is indicated by a broken arrow. Even if the distance between the subheads is further increased, the head is shifted by the same increment with respect to the sheet for each scanning operation.

FIG. 6 is a diagram showing another embodiment. A head 60 constituted by the sub heads 61, 62 and 63 scans the recording medium sheet 64. Each subhead has a series of triads of nozzles 65, 66, and 67, with each nozzle separated by two lines. These sub heads are separated by 7 lines. For each scanning operation the head is moved a distance equal to the number of nozzles in the head, i.e. 9
Move by line.

FIG. 7 is a block diagram of a printer 70 suitable for the embodiment shown in FIGS. The printer 70 receives data from a data source 72 at a controller 74. This controller 74 is connected to the data source 7
2 functions as a communication interface with the device. Data is sent from the controller 74 to the image data state machine 78.
The state machine 78 writes the data to a block buffer (RAM) 80 which is also a partial page memory. This input data is data of a conventional raster scanning format. This data is stored in the print head 8 in an order corresponding to the physical structure of the print head.
2 is read from the buffer 80 for printing.

The system processor 76 includes the printer 7
0 overall control is performed. In this processor, an operation program is stored in the ROM 84, and information being processed can be stored in the RAM 86 and searched. The system processor 76 controls the mechanical system 8 of the printer.
8. Thermal system 90 and front panel controller 92
Receives information that changes every moment. State machine 7
8 also exchanges the position information with the carriage servo 94 of the print head. The carriage servo 94 adjusts the position of the print head with respect to the recording medium based on the read data.

FIG. 8 is a block diagram showing the structure of the state machine 78 of FIG. 7 for controlling writing and reading of pixel data in more detail. Information from controller 74 is received by command separator 96. This command separator 96 identifies the information as data or a system command. System commands are sent to the system processor 76. For data, the address generator 98 in the block buffer 80
The data write and read operations are performed with respect to the address specified in. The interlaced ROM 99 to which the read data is sent selects the appropriate bit of the 8-bit data word stored in the look-up table and controls whether each jet nozzle prints.

8 bits from the block buffer 80
The data contains two pixel data of 4 bits each. Each bit of the pixel data is composed of three primary colors (cyan,
Magenta, yellow) and black information. ROM99
The data of 8 bits to be input to the memory includes 7 bits of the jet number and 1 bit of the mode selection of the address reading. According to the 7-bit jet number data, which of the four color bits is to be output as a 1-bit serial output is selected.

An edge sequence logic circuit 100, which will be described later in detail as an embodiment of the print control apparatus according to the present invention, receives a position signal and a (forward / reverse : F / R ) direction signal from a position counter circuit 102, and receives a recording medium. The nozzles of the printer are controlled so as to print only the image area. The circuit 102 sends control information to the carriage servo circuit 94 and receives position information from an encoder provided on the head carriage, as described later.

The 1-bit data path is routed through the edge sequence logic circuit 100 to the serial head
It leads to a buffer 104. This buffer 104
It has a function of temporarily storing 98-bit serial data from the logic circuit 100 before sending it to the head.

Sequencer 106, which is also a timing and control signal generator, operates in response to management commands sent from system processor 76 in accordance with microcode instructions in ROM 108. Sequencer 106 controls the read and write addresses of address generator 98,
Reprocesses the data needed to send the corresponding pixel data to the print head. This operation is coordinated by the carriage movement logic and print head carriage position information supplied via the position counter circuit 102.

FIG. 9 is a more detailed block diagram of the address generator 98. This embodiment is designed to control the printing of the head nozzle array 110 of FIG. 10 described below. The head nozzle array 110
It includes a first sub-head 112 of nozzles 114, each nozzle in this sub-head being horizontally separated by a distance A from an adjacent nozzle and vertically by one line. The second sub head 116 includes the same number of nozzles 114, and the relative arrangement of the nozzles in this sub head is the same as in the case of the first sub head. However, the uppermost nozzle of the second subhead is separated from the lowermost nozzle of the first subhead by a distance B (represented by the number of pixel intervals or address value intervals) in the horizontal direction and by one line in the vertical direction. I have. Accordingly, the offset address value of the uppermost nozzle of the second subhead is a value obtained by adding the value of B to the position of the lowermost nozzle of the first subhead.

The distance A is equal to the width of 10 pixels,
Assuming that one line includes 3000 pixels, each nozzle is located at the 2990th position in order from the position of the next adjacent nozzle in the subhead. The head of this embodiment uses every other nozzle when scanning in one direction, and prints using the remaining nozzles when scanning in the other direction. Therefore, it is only necessary to move the position of the head with respect to the sheet at a rate of once for every two scanning operations. However, the effective space for address control of the print head can be increased in either scanning direction. 5 and 6 can be realized by increasing the space between the subheads 112 and 116.

Also, in the embodiment, each sub head has 48
Including two nozzles, the two sub-heads are farther apart in the horizontal direction than in the vertical direction as shown in the embodiment of FIG. Printhead 82 'Head Array 1
At 31, the vertical interval C between the ink jet nozzles is set to an appropriate interval so that all the lines of the image area 132 bounded by the broken line 133 on the print medium 13A can be printed. Head array 131
Include first and second sub-heads 135 and 136 having nozzles 137, respectively. The horizontal interval D between these two subheads is equivalent to 44 pixels, and the horizontal nozzle interval E of each subhead is equivalent to 10 pixels. The nozzle groups of the sub heads 135 and 136 shown in FIG. 11 are numbered 0 to 9 and 10 to 19 for convenience. As described above, each subhead is actually 48
Nozzle groups 135 and 136 are numbered 0-47 and 48-95, respectively.

This embodiment is highly useful because one subhead can be used for black printing and the other subhead can be used for color printing. The color subhead has three subtractive primary colors (cyan, magenta, and yellow)
Including three parallel nozzles in the sub head,
It can be realized by providing nozzles as three blocks. This is an example of interlaced printing.

The printer 70 can be designed in any form. Clearly, with a few modifications, alternative designs are available. For example, the designs of FIGS. 8 and 9 can both be realized by adjusting the increment value of the head or the subhead and the offset amount between the subheads.

When the input data in the raster scanning format is a block
The data is written to the buffer 80. The address that determines the memory location where this input data is written is generated by a simple write address up counter 118. This address counter is incremented each time one byte of data is written. Therefore, starting address 0
Pixel data stored in memory in the same order from
Supplied from a controller or data source. system·
By reading the current value of the address counter at any time, the processor can determine how much data has been written to the memory.

If the block buffer memory 80 stores enough data to start printing, the reformatting process of these data is started. From the point of the reformatting process, the memory access is executed under the control of the sequence of the sequencer 106 and the control logic. This control is controlled by a micro program stored in the ROM 108.

The pixel data is reformatted by calculating the addresses to be read out in a specific order different from the sequence in which the pixel data was written. It is the binary full adder 120 that performs this address calculation. The full adder 120 includes a column value register 122, an increment register 124, a pointer P0 register 126, and a pointer P1 register 128.
, And the previously calculated value stored in the latch 130 to perform address calculation. The address selector 132 determines whether data is being written to or read from the block buffer.
Either the address of the write address counter 118 or the value of the latch 130 is selected.

Numerical data from the logic circuit 102 for controlling the position of the print head is stored in the column value register 12.
2 is stored. This numerical data is defined as a pixel position (column value) from the leftmost end of the image below the rightmost nozzle of the first subhead nozzle group of the print head. The system processor 76 has the other three
Calculate the contents of the two registers and store the result. The value in the increment register 124 is constant for the entire image and is related to the width of the image and the design of the print head. For the particular print head described above, this increment is equal to the value of the image width (a number in pixels) -A. In the above example, 300
0 (the number of pixels) −10 = 2990. In the example of FIG. 10, since the value of A is 1, the increment value is 2999 assuming that all the nozzles are used.

The value in the pointer register is used to associate the current read address with the address where the data was originally written. When the first print position of the print head is determined by the current pass of the image printing operation, the value of the pointer P0 register 126 is the address of the first pixel position of the top line of the image to be printed. . In the case of a separated type head array having nozzle sub-heads provided at intervals in the vertical direction as in the present embodiment, the value of the pointer P1 register is a value obtained by subtracting the horizontal offset B from the value of the pointer P0 register. Corresponding to In the case of the head array shown in FIG. 10, the value of the pointer P1 register is a value obtained by adding the offset B to the line length (number of pixels).

FIG. 12 is a flowchart showing an embodiment when an image is printed according to the present invention. Block 140
Write the input data element with. Block 142
Increments the write address counter, and at decision block 144 it is determined whether enough data (initial batch data) to start printing has been written. If no, another input data element is written to the last incremented address.

Once the initial batch data has been written to memory, block 146 calculates the increment value A,
Write it to the increment register. In block 148, the values of pointers P0 and P1 are calculated and stored in corresponding registers. At block 149, the print head position data indicated by the column value is written to the register. At block 150, a read start address (LATCH) equal to the sum of the column value and the pointer P0 is stored in the latch 130. At block 152, the memory element at this address is read from memory.

If it is determined at block 154 that the first subhead of the data element has not been read, block 156 sets the new address value of latch 130 to the previous address plus the increment value. I do. Simultaneously with this process, another input data element is written to memory at block 158 and block 16
At 0, the write address counter is incremented.
Thereafter, at block 152, the newly addressed memory data element is read and the pixel data
It is determined again whether the first subhead of the element has been read. If the determination in block 154 is yes, block 162 determines whether the next data element to be read is the first data element of the second subhead. If yes, block 164 sets the address value (LATCH) of latch 130 equal to the sum of the column value and pointer P1. This is to accommodate an embodiment of a head having two vertically spaced nozzle subheads. In the embodiment of FIG. 10, the value of the latch is set equal to the sum of the previous value and the offset value of pointer P1. Then, the data at this address
The element is read as in the case of the data element of the first subhead, and this operation is continued until the last element of the second subhead is read. Block 166
It is determined whether or not the reading of the second sub head has been completed.

When the nozzle position reaches the end of the second subhead, block 168 determines whether the current pass of the print head has been completed, and if yes, block 170 has completed printing the image. Determine whether or not.
If no at block 168, the position of the head moves to the next column at block 172. At block 149, the new column value is written to register 122 and the process is repeated until the current pass of the head is completed.

At the completion of each pass of the head, it is determined at block 170 whether printing of the image has been completed. If no, the head moves to the position of the new line group at block 174 and a new head pass begins. The above-described processing started by setting the pointers P0 and P1 in block 148 continues until the printing of the image is completed, and ends when the printing is completed.

The design of a memory array used as a block buffer 80 with the pixel data reformatting logic described above presents some particular difficulties. Increasing the capacity of this memory array so that images can be stored at one time was considered undesirable because of the increased cost of large memories. Therefore, it was considered necessary to have a method of temporarily storing data using a smaller partial page memory during the reformatting process of the pixel data. This reformatting process must be performed without losing the relationship between the data write address and the read address, and the algorithm used for the pixel data reformatting process must not be complicated.

The capacity of the block buffer memory 80 is not large enough to store all pages, that is, all image data. When enough data has been written to the memory, the last part of the memory returns to the first part and writes the data with the read and write pointers. This cyclic write operation of the memory is performed by generating a write address by a simple up counter corresponding to the length of the memory. For example, 8
For 256 kilowords of memory in bit words,
The write counter that controls this memory is configured to overflow with a count value of 256 kilobytes (262144). Therefore, when data is written to the last byte of the memory, data is then written to the byte at address 0.

In order to use such a memory, it is necessary to keep track of the pointer. Memory addresses are only meaningful for these pointers. In other words, data writing is started from a position related to the write pointer, and data is read from a position related to the read pointer. The problem of accurately maintaining the relationship between these read and write data ultimately results in the problem of accurately maintaining pointers at distant address locations in memory. In the embodiment described above, this control is performed by the system processor. The read pointer starts at address position 0. When data is written to memory by external logic, the write pointer counter 118
Is incremented as described with respect to FIG.
This increment operation is continued until the write pointer reaches a set numerical value exceeding the read pointer.
In the case of the embodiment, the set numerical value is 50 lines × the number of pixels of the width of the image, for example, 3000 pixels. Since the print head is printing 48 consecutive lines, it can be sure that enough data elements have been written to complete the pass. As described in the flowchart of FIG. 12, this is the value of the data element of the initial batch written to memory.

During read and print operation cycles, new data sufficient to perform the next pass is written to memory. At the end of the current pass, the system processor checks the value of the write pointer and enters the necessary additional data to advance the value of the write pointer by at least the same set value before the value of the read pointer. To do. Therefore, since the pixel data is always decoded with respect to the read pointer stored in the pointer P0 register 126, it is not necessary to pay attention to the absolute memory address value in the reformatting process of the pixel data. By utilizing the concept of the partial page memory, the minimum capacity required for the memory can be significantly reduced as compared with the capacity of a memory for storing pixel data of all pages. The minimum amount of this memory is
This is about twice the number of addresses between the read pointer and the write pointer. 8 pixel data elements
Since each bit address can be stored, a memory capacity of 150 kilobytes can store 300 kilo data elements. Thus, 256 kilobytes of memory is sufficient to implement this method. In order for the memory to operate properly in this manner, all logic devices or software affecting the address of the memory must be configured to overflow with the same value. Thus, using 256 kilowords of memory, the software algorithm for calculating the memory address counter, the binary full adder and the read pointer will overflow when the counter value reaches 256 kilobytes and the counter value will overflow. Must be designed to return to zero.

FIG. 13 is a block diagram showing an embodiment of the encoder 180. Within this encoder is provided a linear relative position strip 182 having a plurality of sequentially increasing graduations. The length of the strip 182 is sufficiently longer than the maximum width of the recording medium. This strip 18
Reference numeral 2 is attached to a frame that is fixedly related to the recording medium.

In FIG. 13, a position on the strip is indicated by an index marker 186 located at the center of the strip 182. The index marker 186 is used for calibration of a device for detecting the carriage position of the head, corrects a position detection error caused by mechanical vibration and electronic noise of the device, and reliably prevents accumulation of errors.

The position marker detecting device 188 is fixed to a print head provided on the carriage of the printer, and moves along the strip 182 to move the position marker 1.
84 and index marker 186 are detected. The detector 188 includes a light emitting diode 190 and corresponding photodiodes 191, 192 and 193. The photodiodes 191 and 193 generate signals that are 90 degrees out of phase with each other, and
4 is detected. Diode 191 generates a sine wave signal, and diode 193 generates a cosine wave signal.
The diode 192 generates an index signal for detecting the index marker 186 in synchronization with the sine wave signal generated by the diode 191.

The output signals of these photodiodes are output via an appropriate amplifier 194 . The sine wave signal and the index signal are supplied to the load port of the 16-bit counter 198 via the NAND gate 196. The 16-bit input of the counter 198 is preset , ie, calibrated, to center position data representing the position of the index marker 186. The cosine wave signal and the sine wave signal are supplied to the quadrature encoder / logic circuit 200, and a signal indicating the occurrence of the position marker 184 is obtained by the encoder. The signal is supplied to the clock terminal of the counter 198. Another signal indicating the moving direction of the carriage is sent from the encoder 200 to the counter 198.
Is supplied to an up / down (U / D) count control terminal, and the counter counts up / down according to the moving direction of the carriage.
Perform down counting.

When the position marker detector 188 passes over the index marker 186, a high-level signal is output as an index signal. Since the width of this index signal is equal to the width of the sequentially incremented scale, it overlaps the transition of two adjacent clock signals. As shown, NAND gate 1
Since 96 receives a sine wave signal and an index signal, only one of these two clock signals is supplied to the counter 198. In the 16-bit counter 198, the data at the preset input terminal is output to the output terminal in response to the next rising edge of the clock after the load input signal goes low. The value of the preset input data of this counter can be selected so as to correspond to a positive value exceeding 0 at any possible position of the carriage. Thereby, the configuration of the position control device can be significantly simplified. When the carriage passes the index marker 186 and the counter 198 is preset, the carriage can be moved to a desired position on the left and right, and the counter 198 can count up or down depending on its operation. In the absence of noise or interference, the output of the counter will have any substantial effect due to the presence of the index marker, even if the counter value later passes the value of the index marker equal to the preset value. Never. However, if for some reason substantial positional errors accumulate, these errors are removed when passing through the position of the index marker, and the counter value is set again to the correct value of the index marker. Is done.

As shown in FIG. 13, the index marker 186 is preferably located at the center of the strip 182, ie, at the center where the carriage moves between the ends of the image to be printed. Therefore, no matter how narrow the image to be printed is, the index marker is detected each time the carriage is scanned as long as the image is printed at least in the center of the recording medium. Of course, changing the position of the index marker to another position will produce the same result depending on the minimum width of the image to be printed.

FIG. 13 shows another embodiment for generating the load signal of the counter 198 by a broken line.
In this example, the AND gate 202 is replaced with the NAND gate 19
6 and the load port of the counter. This A
ND gate 202 receives the output of NAND gate 196 and the direction signal of encoder 200. Thus, the preset operation of the counter 198 is executed only when the carriage is moved in the reverse direction, and the preset operation is prohibited when the carriage is moved in the forward direction. There may be situations where such a function is desired.

FIG. 14 is a diagram for explaining an operation state of the print control apparatus 100 according to the present invention of FIG. 1 described later.
As shown in FIG. 14, the print control device 100
Cycles through eight state cycles. This figure shows the nozzle array (print head) 210 when it is located adjacent to the left boundary 212 and the right boundary 214 of the image area 216 of the print medium 218, respectively. This nozzle array has 96 ink jet nozzles (0
To 95).

The sub-head 220 includes 48 nozzles 222 suitable for black printing. These 48 nozzles correspond to nozzle 0 at the lower left end to nozzle 47 at the upper right end. 48 nozzles 224 of the sub head 226
Corresponds from the nozzle 48 at the lower left end to the nozzle 95 at the upper right end. The 48 nozzles of the sub head 226 are 1
There are three sets of six color nozzles each. Note that nozzle 0
And the nozzle 95 are nozzles at both ends of the print head.

There are four head positions adjacent to the two image edges 212 and 214, as indicated by the dashed heads. At the head position 210A, the image edge 21
The nozzle 95 is adjacent to the left side of 2. The position of this left image edge is indicated by LIE (Left Image Edge /
(Left image edge). During state 0, in which the head is located to the left of this position, the nozzles do not print anything. The right end position of the head when nozzle 0 is adjacent to the left image edge 212 is ALI
E (Alternate Left Image Edge). During states 2 and 6 with the head to the right of this position, all nozzles print. In states 1 and 7 in which the head is on the left side of this position, only the nozzles located on the right side of the image edge 212 perform printing.

At the head position 210C, the nozzle 95 is adjacent to the right image edge 214, and this position is
E (Alternate Right Image Edge). During states 2 and 6, all nozzles located to the left of this position will print. During periods 3 and 5 in which the head is located to the right of this position, only nozzles located to the left of the image edge 214 perform printing. The position corresponding to the head column position at the rightmost end of the head is indicated by RIE (Right Image Edge). The period in which the head is on the right side of this position is state 4.

The four head positions 210A to 210
D represents a boundary between four state transitions during movement of the head in each scanning direction. As shown, there are a total of eight states in the head's scan cycle until the head scans the image area 216 forward from left to right and back again to its original position.

FIG. 1 shows a print control apparatus 1 according to the present invention.
FIG. 2 is a block diagram illustrating a configuration of an embodiment of the present invention. The print control apparatus 100 is configured to execute the edge sequence
The printing of the eight states shown in FIG. 14 is controlled by an eight state machine 230 corresponding to the logic circuit 100. The position register 232 included in the state machine 230 includes a head position ALIE together with a direction signal.
And ARIE position data. These position data are compared by the edge comparator 234 with the actual head position data received from the circuit 102 of FIG.
The selector 236 determines, based on the direction signal, when the head has reached one of the image edges. When it is determined that the head has reached the image edge, an enable signal is input to the state transition qualifier 238. The state transition qualifier 238 sends an enable signal to the state counter 240 according to the current state, and
The state value of the state counter 240 is incremented according to the clock signal. State transition qualifier 238 does not function until it receives print enable signal PRNTEN from position counter 102 and indicates that the print head has entered the image area. As used herein, the dot clock signal is a pulse signal generated by the encoder 180 when the print head has moved a distance equal to the width of one pixel (pixel).

The state counter 240 outputs a binary value. This state value is then decoded by state decoder 242 to generate any of the eight state signals that are input to state transition qualifier 238. Decoder 242 also outputs on lead 244 a signal indicating whether the print head has passed the right or left edge of the image based on the current state. Furthermore, 3
An enable signal to the two counters 246, 250 and 252 is also generated.

The decimal counter 246 outputs one pulse for every ten dot clock pulses. As mentioned above, the horizontal spacing between adjacent jet nozzles in the print head is 10 pixels. However, only the interval between the two central nozzles is 45 pixels. The output of counter 246 is provided to one of two enable inputs of head column counter 250 via switch 248. The counter 250 is preset to the first nozzle number across the image edge and then, when enabled by two enable input signals, counts up or down the dot clock pulse depending on the direction signal unless the state changes. . The other enable input of the counter 250 receives the enable signal directly from the state decoder 242. This loads the head column counter 250 with the appropriate starting nozzle number when the head begins to pass the image edge.

Therefore, the head column counter 250
Is incremented by one each time the print head moves 10 pixel columns relative to the image. However, only when the center of the head crosses the image edge, 4
The counter value is incremented according to the movement of 5 pixel columns. This is performed by a 45-digit counter 252 which is also enabled in the state decoder 242. When the center position of the head reaches the image edge,
The switch 248 is switched, and the 45-digit counter 252
Is provided to the enable input of the counter 250 so that the pixel column column can be moved when the center position of the print head has moved exactly 45 pixel columns.
The value of the counter 250 is incremented. Therefore,
The counter value of the head column counter 250 represents information for determining how many nozzles of the head should be printed or not printed according to the positional relationship between the head and the image edge and the moving direction of the head. Counter 2
The value of 50 is input to the digital value comparator 254 and is compared with the jet number of that nozzle as the data for each nozzle is processed. This comparison result output is always “true (high level)” when the head column counter value is smaller than the number of the nozzle currently being processed.

This comparison output is supplied to the state decoder 24
Left and right edge control signals (LEFT) on lead 244 from
/ RIGHT EDGE) to the exclusive OR XOR gate 256. When the signal on lead 244 is high, the inverse of the output signal of digital value comparator 254 is output from XOR gate 256. Also,
When the signal on lead 244 is low, comparator 2
The output of 54 is output from the XOR gate 256 as it is, and input to the print decision AND gate 258 via the AND gate 257. The AND gate 257 sets the print enable signal PRNTEN to “true (high level)”.
The signal from the XOR gate 256 is passed only when
@ND gate 258 functions substantially as a print data enable gate and also receives the serial print data currently being processed. The modified serial print data of AND gate 258 is provided to the print head. Thus, when the output of XOR gate 256 is high, serial print data is provided directly to the print head via AND gate 258. However, XO
When the output of the R gate 256 is low, the output of the AND gate 258 is maintained at "false (low level)", the print is disabled, and printing with serial print data is stopped.

Next, an outline of the operation related to the state transition of the print control apparatus 100 will be described. First, in state 0, the print head moves from the left to the left image edge. First nozzle 95 is left image edge 2
When the signal crosses 12, the print enable signal PRNTEN becomes "true", the print enable state is entered via the sequencer 106, and a state transition is made to state 1. Thereafter, the operation of the print control circuit 100 is started. Upon entering state 1, the value of the head column counter 250 is preset to 95. This head column counter 25
Since 0 is set in the down counter, the count value is decremented to 94 according to the first clock. The processed data is sequentially supplied to the nozzles 0 to 95 of the head via the print data enable gate 258, and at the same time, the data of the jet number (nozzle number) of the binary value corresponding to each bit of the print data The value is provided to digital value comparator 254. At this point, the condition that only the data of jet number 95 is larger than the head column count value can be satisfied by the operation of the digital value comparator 254, the XOR gate 256, and the AND gate 258, so that only the data passes through the AND gate 258. However, the print data of the other nozzles are all “0”. After all 96 print data have passed through gate 258, the system waits for a dot clock pulse to occur when the head reaches the next pixel column.

For the next nine dot clock pulses, the above process is exactly the same, with only the jet number data being sent to the head through AND gate 258. However, when the tenth clock pulse occurs, the count value of the head column counter 250 is decremented to 93 in accordance with the carry output pulse from the decimal counter 246. At this point, the operation of the jet numbers 95 and 94 can be performed by the operation of the digital value comparator 254 and the XOR gate 256 and the like. This condition continues until the print head moves right by the next ten pixel columns. When the above operation is repeated and the area at the center of the head at an interval of 45 pixels reaches the image edge, the switch 248 is turned on.
Is switched from the decimal counter 246 to the 45-digit counter 252, and the state is appropriately maintained for the movement time at the center interval. When the entire print head has passed the left edge of the image, the counting operation of the counter in the print control device 100 is stopped, and the value of the head column counter 250 is set to zero. At this point, the circuit enters state 2,
Head column counter 250 according to next clock
Is preset to 95. When the value of the head column counter is set to 95, the circuit enters state 3. In this state 3, all the jet nozzles of the print head can print, and the entire print head is located on the image. In this state 3, the XOR gate 2
The signal of the 56 input control lines 244 becomes "false", and all jet numbers equal to or less than the value of the head column counter can be printed. That is, all jet numbers (0 to 0)
Since 95) is equal to or less than the value of the head column counter 95, all the jet nozzles execute the printing operation according to the print data.

State 4 is entered when the print head reaches the right edge of the image. In this state 4, the head column counter 250 starts counting down from the first clock after the column position C = ARIE. After this clock generation, the value of the head column counter becomes 94, and the nozzles of jet numbers 0 to 94 can print. As described above, the value of the head column counter is decremented every time the head moves 10 pixels to the right and counts 10 dot clock pulses, and one jet nozzle is disabled (printing is stopped). ) State. That is, zero data is supplied to the disabled jet nozzles instead of print data.

When the print head has completely passed the right edge 214 of the image, the condition C ≦ RIE is no longer true.
Instead, the print enable signal PRNTEN becomes “false”. Thus, the printing operation is stopped. afterwards,
The print head reverses the direction of movement and starts moving to the left. When the print head passes the RIE position again, the PRNTEN signal becomes "true" and printing can be performed again. At this time, since the value of the head column counter is 0, only the nozzle of jet number 0 can print at first. Thereafter, the head column value is incremented by one for every ten dot clock pulses, the other jet nozzles can be sequentially printed, and finally all the jet nozzles are ready for printing.
At this point, the circuit enters state 5. In state 5, as in state 3, all jet nozzles perform a printing operation. That is, the head column counter 250 counts 95
, The printing of all jet nozzles becomes possible.

When the print head reaches the left image edge 212 again, the circuit enters state 6. This state 6 continues for one clock period just for the purpose of presetting the value of the head column counter in accordance with the next clock, similarly to the state 2, in which case the next preset value is 0. is there. When counter 250 is set to 0 at the next clock, state 7 is entered. In this state 7, XOR
The signal of the control line 244 input to the gate 256 is “true”
Thus, only nozzles having a jet number larger than the value of the head column counter can be printed. That is, since the set value of the counter 250 is 0, the jet numbers 1 to 9
Up to 5 nozzles can be printed, jet number 0
Only the nozzles cannot print. As mentioned above, 1
For every 0 dot clock pulses, the head column
The value of the counter 250 is incremented, and further nozzles cannot be sequentially printed. The above process is repeated until the value of the counter 250 reaches 95, at which time the state becomes 0. Since the condition of C ≧ LIE becomes “false” at the next clock pulse, the print enable signal PRNT
EN is also false. As a result, the printing operation is stopped, the counting operation of the head column counter 250 is also stopped, and the system waits until the print enable signal PRNTEN becomes “true” again by moving the head from left to right.

The print control device 100 shown in FIG.
Table 1 below shows a change in state due to the movement of the print head array 210 as shown in FIG. The state table of Table 1 summarizes the above-described state transition operation of the print control apparatus 100 of the present invention. In the table, “DIS” is disabled, “EN” is enabled, “J”
"A" represents a jet number.

[0065]

[Table 1]

The present invention is directed to any design of a printhead having two differently spaced linearly arranged nozzle groups.
Note that the head is equally applicable.
Further, by adding an N-ary counter as appropriate, it can be applied to almost all conceivable print heads. In the preferred embodiment, the color
The nozzle subhead 226 includes three sets of 16 nozzles, with each set of nozzles being assigned a different color, and the jet number of the nozzle representing the color of that nozzle.
That is, since the jet number and the color of the nozzle have a one-to-one relationship, the color can be directly represented by the binary code of the jet number. Obviously, the controller of the present invention is applicable to other types of print heads.
Further, while the above-described controller is used to modify the serial print data sent to the print head,
It can also be used as a device for separately supplying an enable signal or a disable signal to the jet nozzle.

[0067]

According to the present invention, there is provided a print control apparatus comprising: an index marker indicating a center of a movement path of a print head; and a position marker having a plurality of position markers provided along both sides of the index marker along the movement path. Means for detecting the index marker of the position marker means according to the movement of the print head to calibrate the position information of the print head, detecting a plurality of position markers of the position marker means, and detecting the detected position. Position detecting means for counting the number of markers to detect position information of the print head and detecting whether each of the plurality of print elements is at a predetermined position for forming a predetermined image, and an output signal thereof And data control means for controlling image data supplied to each print element in accordance with Therefore, since the position information of the print head can be directly and accurately detected from the marker means, it is also possible to accurately detect whether each of the plurality of print elements is at a predetermined position for forming a predetermined image. . In particular, since the index marker for calibrating the position information of the print head is at the center of the movement path of the print head, even if there is an error in the count of the position marker, the movement of the accumulated number of position markers is large. Prints detected at the end of the path
The head position error can be significantly reduced (compared to the case where the index marker is at the end of the movement path). Therefore, in accordance with the output signal of the position detecting means, the image data is supplied to the print element at the predetermined position, and the control data for stopping the printing operation is supplied to the other print elements, so that the predetermined image can be reproduced at high speed. When printing, the position of the print head can be adjusted without using a complicated configuration or large-capacity memory as in the past.
By minimizing information errors, accurate print control can be performed without errors.

[Brief description of the drawings]

FIG. 1 is a lock diagram of a preferred embodiment of a print control device according to the present invention.

FIG. 2 is a diagram illustrating an example of a printer device suitable for the present invention.

FIG. 3 is a diagram illustrating an interlaced scanning operation of a printer device suitable for the present invention.

FIG. 4 is a diagram illustrating another scanning operation of the printer device suitable for the present invention.

FIG. 5 is a diagram illustrating another scanning operation of the printer device suitable for the present invention.

FIG. 6 is a diagram illustrating still another scanning operation of the printer apparatus suitable for the present invention.

FIG. 7 is a block diagram illustrating an example of a configuration of a printer device suitable for the present invention.

FIG. 8 is a block diagram showing one embodiment of the image data state machine of FIG. 7;

FIG. 9 is a block diagram showing one embodiment of the address generator of FIG. 8;

FIG. 10 is a diagram showing an embodiment of an ink jet head suitable for the present invention.

FIG. 11 illustrates an embodiment of a portion of an ink jet head suitable for the present invention.

FIG. 12 is a flowchart showing an embodiment of the operation of the printer of FIG. 7;

FIG. 13 is a diagram showing an embodiment of a print head position detecting mechanism suitable for the present invention.

FIG. 14 is a diagram for explaining the operation of the printer control device of the present invention.

[Explanation of symbols]

 232 Left and right edge position register 234 Edge comparator 238 State transition qualifier 240 State counter 242 State decoder 246 Decimal counter 250 Head column counter 252 45-decimal counter 254 Digital value comparator 256 XOR gate 257 AND gate 258 AND gate

Continued on the front page (72) Inventor Richard A. Springer 97062, Oregon, United States of America Tallatin South West Ninetys Avenue 21389 (56) References JP-A-2-47076 (JP, A) JP-A-61-23463 (JP, A) JP-A-1-221271 (JP, A) JP-A-64-49652 (JP, A) JP-A-56-79306 (JP, A)

Claims (1)

(57) [Claims] A print head having a plurality of print elements is moved in a predetermined direction on a recording medium,
A print control device for a printer that drives each of the plurality of print elements based on image data and forms a predetermined image corresponding to the image data on the recording medium, the movement path of the print head. Position marker means having an index marker indicating the center of the position marker and a plurality of position markers provided along both sides of the index marker on both sides of the index marker; Detecting an index marker to calibrate the position information of the print head, detecting the plurality of position markers of the position marker means, counting the number of detected position markers, and counting the number of the detected position markers. position information
Detecting the distribution, and position detecting means for each of said print element generates a signal indicating whether the predetermined position to form the predetermined image, receives an output signal of said position detecting means, the A print control means for sequentially supplying the image data to the print element at a predetermined position and supplying control data for stopping the print operation to the other print elements. Control device.