JP2003159839A - Print system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To surely compress a volume of print data being transmitted at a time to a half or less through an extremely simple compression technology regardless of image data. <P>SOLUTION: In the print system where a personal computer 2 performs overwrite printing based on print data being transmitted from a personal computer 1, a section 13 for generating a plurality of pieces of compressed data depending on the number of times of overwriting by decimating print data of single time regularly, a section 14 for generating mask pattern data which validates data at a non-decimated position and invalidates data at a decimated position in order to exhibit regularity, and a section 15 for transmitting the compressed data and mask pattern data are provided on the personal computer 1 side. The user logic section 214 of an ASIC 21 develops received compressed data to original print data based on the mask pattern data. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing system in which a printing device performs a printing operation based on print data transmitted from an external device.

[0002]

2. Description of the Related Art Generally, a serial printer prints while scanning a print head and carries out printing by repeating conveyance of a recording sheet in response to scanning of the print head. Therefore, in the serial printer, it is usual that print data corresponding to one scan of the print head is stored in the printer side. In order to store the print data for one time, the conventional printing apparatus has a memory having a capacity of 1 Mbit in the ASIC.

Further, in such a serial printer,
In order to reduce the data transmission time of print data transmitted from a personal computer which is an external device to the serial printer, the print data is transmitted after being subjected to various compression processes.

For example, the one disclosed in Japanese Unexamined Patent Publication No. 8-18800 has an output buffer unit for holding one band of line data corresponding to the width of a recording head for expanding and storing print data and performing an output process. The section identifies the transmitted data, and in the case of compressed data, it outputs the data of the mth line of the (n + 1) th band based on the difference from the data of the mth line of the nth band held in the output buffer section. make,
When the data of the m-th line of the n-th band is overwritten with the created line data and the transmitted data is blank data, the data of the m-th line of the output buffer section is erased and the data is not compressed In this case, the m-th line data in the output buffer section is overwritten with the received data.

[0005]

However, even if the print data is compressed by using the above compression technique, a memory having a capacity enough to store one print data, that is, a memory having a capacity of 1 Mbit is required. Since it needs to be installed, there is a problem that the memory size cannot be reduced.

Further, in addition to the above-mentioned compression technique, it is possible to compress the print data amount for one time by using a run-length compression technique used in a facsimile machine or the like. However, to what extent the image data can be compressed by the run-length compression technique depends on the target image data.For example, in an image in which white and black are alternately continuous, the data capacity increases conversely. There is a possibility that it will end Therefore, the conventional serial printer is currently equipped with a 1-Mbit memory in the ASIC so that the uncompressed print data for one time can be stored even if the data can be compressed.

The present invention was devised to solve such a problem, and an object thereof is to reliably reduce the amount of print data transmitted at one time to half or less by an extremely simple compression technique regardless of image data. It is to provide a printing system that can be compressed.

[0008]

A printing system according to the present invention is a printing system in which a printing device performs overwriting printing based on print data transmitted from an external device,
The external device side regularly thins out the print data for one time so that a plurality of 8
Compressed data creating means for creating compressed data of less than or equal to bits and 12-bit mask pattern data for validating data at non-thinned positions and invalidating data at thinned positions to show regularity The printer includes a mask pattern data creating unit and a transmitting unit that transmits the compressed data and the mask pattern data, and the printing device converts the 12-bit mask pattern data into 16-bit mask pattern data. Based on the compressed data storage means for storing the compressed data of 8 bits or less, the 16-bit data converted by the data conversion means, and the compressed data of 8 bits or less stored in the compressed data storage means, Data expansion output means for expanding and outputting the original 16-bit print data,
The number of bits corresponding to the number of nozzles in one vertical column of the print head is provided, and the data decompression output means includes 16 signal lines output from the data conversion means and the compressed data storage means. By arranging the eight signal lines output from the above in a matrix, and arranging AND circuits at 16 intersections corresponding to the mask pattern data respectively and taking the logical sum of both signal lines, It is characterized in that compressed data of 8 bits or less is expanded into original 16-bit print data and output.

According to the present invention having such characteristics,
The compressed data creation means creates a plurality of compressed data of 8 bits or less according to the number of overwriting by regularly thinning out the print data for one time. Ie 2
8 (= 16/2) bit data in case of overwriting once,
Compressed data is created such as 6 (≈16 / 3) bit data in the case of three-time overwriting and 4 (= 16/4) bit data in the case of four-time overwriting.

The max pattern data creating means creates 12-bit mask pattern data that makes the data at the positions not thinned out valid (1) and makes the data at the thinned positions invalid (0). For example, in the case of overwriting twice,
(1,0,1,0,1,0,1,0,1,0,1,0)
12-bit mask pattern data is created. In the case of overwriting three times, (1,0,0,1,0,
12-bit mask pattern data of 0, 1, 0, 0, 1, 0, 0) is created. Similarly, the mask pattern data for four times of overwriting and for six times of overwriting are created. The transmitting means transmits the compressed data and the mask pattern data to the printing device side.

On the other hand, the data conversion means of the printer converts the transmitted 12-bit mask pattern data into 16-bit mask pattern data. For example, in the case of overwriting twice, it has been sent (1,0,1,0,
12-bit data of (1,0,1,0,1,0,1,0) is converted into (1,0,1,0,1,0,1,0,1,0,1,
0,1,0,1,0) 16-bit data.

The data decompression output means outputs 8 bits based on the compressed data of 8 bits or less stored in the compressed data storage means and the 16 bit data converted by the data conversion means.
The compressed data of less than or equal to bits is expanded to the original 16-bit print data and output.

The data conversion means, the compressed data storage means, and the data expansion output means are provided in a number capable of outputting the number of bits corresponding to the number of nozzles in one column of the print head. That is, the number of nozzles in one vertical line of the print head is
There are 208 nozzles for monochrome (black) and 192 nozzles for color. On the other hand, since the print data output from the data decompression output means is 16 bits, 13 data conversion means, compressed data storage means and data decompression output means are provided for monochrome (= 208 ÷ 16). .

Here, the data decompression output means arranges the 16 signal lines output from the data conversion means and the 8 signal lines output from the compressed data storage means in a matrix form, and the mask pattern. An AND circuit is arranged at each of 16 intersections corresponding to data, and the original 16-bit print data is output by taking the logical sum of both signal lines.

As described above, according to the present invention, in the case of overwriting two times, every other print data is thinned out, so that the amount of print data transmitted at one time is halved. . Further, in the case of overwriting three times, every other two data are thinned out, so that the data amount of the print data transmitted at one time becomes 1/3. Similarly, in the case of four times of overwriting, the data amount of print data transmitted at one time becomes 1/4, and in the case of six times of overwriting, print data transmitted at one time. The data amount of is reduced to 1/6. In other words, since the amount of print data sent at one time is at least 1/2 or less, the memory mounted on the ASIC can be reduced from the conventional 1M bits to 500K bits, which is half that amount. , It is possible to reduce the memory size. Also, the amount of data transmitted at one time is 1/2
Because of the following, the communication time between the external device and the printing device can be shortened.

Further, the printing system of the present invention is a printing system in which a printing device performs overwriting printing based on print data transmitted from an external device, wherein the external device side regularly prints one print data. By dividing the data into a plurality of compressed data according to the number of overwriting and transmitting them sequentially, the mask pattern data showing the regularity is created and transmitted, and the printing device receives the compressed data. Is developed into original print data based on the mask pattern data and printed.

According to the present invention having such characteristics,
By regularly thinning out the print data for one time, the compressed data is divided into a plurality of compressed data according to the number of overwriting and transmitted, so that the data amount of the print data transmitted at one time can be reduced. . As a result, the capacity of the memory mounted on the ASIC can be made smaller than that of the conventional one, and the memory size can be reduced accordingly. Moreover, since the amount of data transmitted at one time is reduced, the communication time between the external device and the printing device can be shortened.

Data in which the compressed data is data of 8 bits or less, and the mask pattern data makes the data in the positions not thinned out valid (1) and the data in the thinned positions invalid (0). Has become. As described above, by using the mask pattern data, the data can be compressed by a simple method such as regularly thinning out the print data for one time. Also, the data can be reliably compressed.

Further, the printing device makes the data of the positions not thinned out valid and invalidates the data of the thinned positions 1
Based on the data conversion means for converting 2-bit data into 16-bit data and the 16-bit data converted by this data conversion means and the compressed data of 8 bits or less,
Data expansion output means for expanding compressed data of 8 bits or less into original 16 bits of print data and outputting the data is provided. This makes it possible to reliably expand the compressed data of 8 bits or less into the original 16-bit print data.

The data conversion means is adapted to generate mask pattern data corresponding to other compressed data, based on the mask pattern data corresponding to one compressed data. For example, in the case of overwriting twice, if the compressed data is divided into two, it is necessary to create mask pattern data for each compressed data.
Since the other one mask pattern data is created by the data conversion means on the printing device side, the external device side only needs to create and send one mask pattern data, and the load on the external device side is reduced. Since the transmission data is also reduced, the transmission time can be further shortened.

The data decompression output means is a matrix of 16 signal lines output from the data conversion means and 8 signal lines output from the compressed data storage means storing compressed data of 8 bits or less. In parallel with each other, AND circuits are respectively arranged at 16 intersections corresponding to the mask pattern data, and the logical sum of both signal lines is taken to convert the compressed data of 8 bits or less into the original 1
It is configured to be expanded into 6-bit print data and output. That is, with a simple circuit configuration such as an AND circuit,
The original 16-bit print data can be surely expanded.

The data conversion means, the compressed data storage means, and the data decompression output means are provided by a number capable of outputting the number of bits corresponding to the number of nozzles in one vertical column of the print head. As a result, the print data for the nozzles in one vertical column of the print head can be output at the same time, and the printing time can be shortened.

Further, only one set of such data conversion means, compressed data storage means and data expansion output means is provided, and mask pattern data input to the data conversion means and compressed data stored in the compressed data storage means. And 16-bit data output from the data expansion output means,
A configuration may be provided that includes a second switching unit that switches at a predetermined timing and outputs as data corresponding to the number of nozzles in a single vertical column of the print head. With this configuration,
Although the first switching means and the second switching means are required, it is not necessary to provide 13 sets of the data conversion means, the compressed data storage means, and the data decompression output means, so that the circuit configuration can be simplified as a whole. it can.

The printing system of the present invention is a printing system in which a printing device performs a printing operation based on print data transmitted from an external device, wherein the external device side prints one print data in the main scanning direction. Compressed data that is thinned out every other space is created along (the moving direction of the print head), and this compressed data is transmitted as print data for one time, and the printing device receives the compressed data in dot units in the main scanning direction. It is characterized in that one dot is printed by continuously printing two dots for each.

According to the present invention having such characteristics,
With an extremely simple data compression technique, the amount of print data transmitted from an external device to the printing device can be halved. Further, the printing device side can also develop the original print data with an extremely simple data development (restoration) technique. Therefore, the circuit configuration becomes extremely simple, and the product cost can be suppressed.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a system configuration diagram of a printing system showing a first embodiment of the present invention. This printing system is a system in which a printer 2 as a printing device performs a printing operation based on print data transmitted from an external device such as a personal computer 1.
Therefore, the personal computer 1 and the printer 2 are connected via the communication cable 3 capable of bidirectional communication.

The personal computer 1 is equipped with a so-called printer driver. This printer driver analyzes a print data storage unit 11 for storing print data and print data and commands stored in the print data storage unit 11. The data analysis unit 12, the compressed data creation unit 13 that creates a plurality of compressed data according to the number of overwriting by regularly thinning out the print data for one time, and the thinning-out to show the regularity. Validate the data of the position that was not missed,
A mask pattern data creation unit 14 that creates 12-bit mask pattern data that invalidates the data at the thinned positions, and a data transmission / reception unit 15 that sends the compressed data and mask pattern data are provided.

On the other hand, the printer 2 includes an ASIC 21 which is a logic circuit IC dedicated to the printer and a CPU 22 which controls the ASIC 21. The CPU 22 includes a ROM 23 that stores a program for executing a printing operation,
A RAM 24 is connected to each of which stores various data and serves as a work area during a printing operation.

In the ASIC 21, a feed motor 25 for feeding a print sheet (not shown) to a print position and a carrier (not shown) equipped with a print head 27 are provided in a direction (mainly) orthogonal to the feed direction (sub-scanning direction) of the print sheet. (Scanning direction)
A carrier motor 26 for reciprocating the print head 27 and a print head 27 for printing data by ejecting ink onto the fed print paper are connected.

The ASIC 21 is a communication port (US) for communicating with the personal computer 1 via the communication cable 3.
B) 211, a buffer memory 212 including an SRAM or the like for temporarily storing the compressed data transmitted from the personal computer 1, a CPU 213, and a user logic unit 214 in which a user arbitrarily designs a circuit. .

In the first embodiment, various circuits for expanding the compressed data into the original print data are constructed in the user logic section 214, which will be described later. Although not shown, the user logic unit 214 is provided with a DMA controller that controls DMA (Direct Memory Access) transfer.

The printing system according to the first embodiment is premised on the conventional overwriting printing. Specifically, two overwritings, three overwritings, four overwritings, 4 patterns of overwriting mode of 6 times of overwriting are prepared. Here, the number of nozzles in one vertical column of the print head 27 is 208 for monochrome (black) and 1 for color.
It has 92 nozzles. That is, the number of bits of the image data of the vertical example of the print head 27 is 208 bits for monochrome (black) and 192 bits for color when 1 bit is assigned to 1 dot. And in the present embodiment,
With 16 bits as one unit, monochrome (black) is 13 (=
208 ÷ 16) blocks, 12 colors (= 192 ÷ 1)
6) Divide into blocks and handle data in units of blocks. That is, in the following description, only one block will be focused on in the description.

The compressed data creation unit 13 creates a plurality of compressed data of 8 bits or less according to the number of overwriting by regularly thinning out the print data for one time. That is, in the case of overwriting twice, 8 (= 16 ÷
2) Bit data, 6 (≒ 16) in case of overwriting 3 times
÷ 3) Bit data, 4 (= 1 when overwriting 4 times)
6 ÷ 4) bit data, 3 (≒) in case of overwriting 6 times
16 ÷ 6) Create compressed data such as bit data.

Here, in order to create compressed data by regularly thinning out, for example, in the case of overwriting twice, printing data for one time is thinned out every other one in the sub-scanning direction to obtain two compressed data. To create. Specifically, for example, among the bit data from No. 1 to No. 208, the odd-numbered (1, 3, 5 ...) Bit data is left first,
The even-numbered (2, 4, 6 ...) Bit data is thinned out to create odd-numbered 104-bit compressed data, and then the even-numbered (2, 4, ...) Bit data is left Thinning out the 1st (1, 3, 5 ...) Bit data,
Even-numbered 104-bit compressed data is created. As a result, the compressed data becomes 1/2 of the original print data.

Similarly, in the case of overwriting three times, it means that three bits of print data are thinned out every other bit in the sub-scanning direction to create three compressed data. Specifically, of the bit data from No. 1 to No. 208, for example, the bit data of 1, 4, 7, 10, ... Is left at the beginning, and the remaining 2, 3, 5, 6, 8, 9, The bit data of ... Is thinned to create compressed data of 70 bits, and then the bit data of 2, 5, 8, 11, ... Is left, and the remaining 1, 3, 4, 6, 7 , 9, 10, ... Bit data is thinned out to create 69-bit compressed data, and finally, 3, 6, 9, 12, ... Bit data is left, and the remaining 1, 2 ,. Bit data of 4, 5, 7, 8, ... Is thinned out to create 69-bit compressed data. As a result, the compressed data becomes about 1/3 of the original print data.

Similarly, in the case of overwriting four times,
Print data for one time is set every other 3 along the sub-scanning direction.
Four compressed data (52-bit data in each case) are created by thinning out bits, and in the case of overwriting 6 times, print data for one time is thinned out every other 5 bits along the sub-scanning direction to create 6 compressed data. Compressed data (35-bit data and 3
6-bit data) is created.

The mask pattern data creation unit 14 uses the overwriting operation of 2 times, the overwriting operation of 3 times, the overwriting operation of 4 times, and the overwriting operation of 6 times in each of the overwriting modes. 12-bit mask pattern data for making the data valid (1) and the data at the thinned-out position invalid (0).

FIG. 2 shows a specific example of mask pattern data in each overwriting mode.

In the case of two-time overwriting (2-pass shingling), the odd-numbered data is made valid by corresponding to each of the two compressed data created above (1, 0,
12-bit mask pattern data (2P1) of 1,0,1,0,1,0,1,0,1,0) and even-numbered data are valid (0,1,0,1,0) , 1, 0, 1,
Two mask pattern data of 12-bit mask pattern data (0, 1, 0, 1) (2P2) are created. However, the second mask pattern data (2P2)
Is created on the side of the printing device 2 described later based on the first mask pattern data (2P1).

In addition, overwriting three times (3-pass shingling
), Corresponding to each of the three compressed data created above, first (1,0,0,1,1,0,0,
12-bit mask pattern data (3P1) of (1, 0, 0, 1, 0, 0) is created, and then (0, 1, 0, 0,
12-bit mask pattern data (3P2) of 1,0,0,1,0,0,1,0) is created, and finally (0,
12 of 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1)
Bit mask pattern data (3P3) is created.
However, the second and third mask pattern data (3P
2, 3P3) are created on the side of the printing device 2 described later based on the first mask pattern data (3P1).

In addition, overwriting four times (4-pass shingling
), Corresponding to each of the four compressed data created above, first (1,0,0,0,1,0,
12-bit mask pattern data (4P1) of 0, 0, 1, 0, 0, 0) is created, and then (0, 1, 0, 0,
12-bit mask pattern data (4P2) of 0, 1, 0, 0, 0, 1, 0, 0) is created, and then (0, 0,
1, 0, 0, 0, 1, 0, 0, 0, 1, 0) 12-bit mask pattern data (4P3) is created, and finally (0, 0, 0, 1, 0, 0, 0 , 1,0,0,0,1)
12-bit mask pattern data (4P4) is created. However, the second, third, and fourth mask pattern data (4P2, 4P3, 4P4) is created on the side of the printing device 2 described later based on the first mask pattern data (4P1).

In addition, 6 times of overwriting (6-pass shingling
), Corresponding to each of the six compressed data created above, first (1,0,0,0,0,0,0,
12-bit mask pattern data (6P1) of (1, 0, 0, 0, 0, 0) is created, and then (0, 1, 0, 0,
0,0,0,1,0,0,0,0) 12-bit mask pattern data (6P2) is created, and then (0,0,
12-bit mask pattern data (6P3) of (1,0,0,0,0,0,1,0,0,0) is created, and then (0,0,0,1,0,0,0) , 0,0,1,0,0)
12-bit mask pattern data (6P4) is created, and then (0,0,0,0,1,0,0,0,0,0,
1,0) 12-bit mask pattern data (6P
5), and finally (0,0,0,0,0,1,0,
12-bit mask pattern data (6P6) of 0, 0, 0, 0, 1) is created. However, the second to sixth mask pattern data (6P2 to 6P6) are created on the side of the printing device 2 described later based on the first mask pattern data (6P1).

FIG. 3 shows a part of the internal configuration of the user logic section 214 of the ASIC 21. However, in the first embodiment, as described above, the number of bits of the image data of the vertical example of the print head 27 is divided into 16 bits,
Since these 16 bits are treated as one unit (in the first embodiment, this unit is referred to as a segment (Segment)), FIG. 3 shows only the configuration of the circuit block A for this one unit (1Segment). It is shown.

That is, in the first embodiment, 12-bit mask pattern data (described as a template in FIG. 3) transmitted from the personal computer 1 side is converted into 16-bit mask pattern data. Data conversion unit 41, compressed data storage unit 42 for reading and storing compressed data of 8 bits or less stored in buffer memory 212, 16-bit data converted by data conversion unit 41, and compressed data storage unit 42. A data decompression output unit 4 for decompressing and outputting original 16-bit print data based on the compressed data of 8 bits or less stored in
3 and 3.

The data conversion unit 41 is composed of 12 registers for storing 12-bit mask pattern data and 16 registers for storing 16-bit mask pattern data.

The compressed data storage section 42 is composed of eight registers so that compressed data of maximum 8 bits can be stored. The data expansion output unit 43 is the data conversion unit 4
16 signal lines m1 to m output from each register 1
16 and eight signal lines n1 to n8 output from each register of the compressed data storage unit 42 are arranged in a matrix form, and AND circuits are respectively connected to 16 intersections corresponding to the mask pattern data. As a result, the logical sum of both signal lines is obtained and expanded into the original 16-bit print data, which is output to the print head 27 (see FIG. 1) via the multiplexer 44.

FIG. 3 shows A in the case of the two-time overwriting mode.
The connection configuration example of the ND circuit is shown. That is, in the two-time overwriting mode, two AND circuits are connected to each of the eight signal lines n1 to n8 output from each register of the compressed data storage unit 42. In particular,
AND circuits are connected to the intersections of the signal line n1 and the signal lines m1 and m2, respectively, and AND circuits are connected to the intersections of the signal line n2 and the signal lines m3 and m4, respectively. ..., signal line n8 and signal lines m15, m
An AND circuit is connected to each of the two intersections of 16.

Although not shown, the signal line n1 and the signal lines m1, m2, and m3 are used in the three-time overwriting mode.
AND circuits are connected to the intersections of the three positions, and AND circuits are connected to the three intersections of the signal line n2 and the signal lines m4, m5, and m6.
AND circuits are connected to three intersections of the signal line n5 and the signal lines m13, m14, and m15, respectively.
An AND circuit is connected to one intersection of 6 and the signal line m16. That is, in this case, the signal line n7 and the signal line n8 are not connected to the signal lines m1 to m16 output from the registers of the data conversion unit 41 and are treated as invalid.

Similarly, in the overwriting mode of four times,
AND circuits are connected to the four intersections of the signal line n1 and the signal lines m1, m2, m3, and m4, respectively, and the four intersections of the signal line n2 and the signal lines m5, m6, m7, and m8, respectively. AND circuits are connected to the signal lines n3 and signal lines m9, m10, m11, and m12 at four intersections, and the AND circuits are connected to the signal lines n4 and m13, m14. AND circuits are respectively connected to the four intersections of m15 and m16. That is, in this case, the signal lines n5 to n8 are not connected to the signal lines m1 to m16 output from the registers of the data conversion unit 41 and are treated as invalid.

Similarly, in the 6-time overwriting mode,
Signal line n1 and signal lines m1, m2, m3, m4, m5, m
AND circuits are connected to the six intersections of 6 respectively, and the signal line n2 and the signal lines m7, m8, m9, m10,
An AND circuit is connected to each of the six intersections of m11 and m12. That is, in this case, the signal line n
3 to the signal line n8 are not connected to the signal lines m1 to m16 output from the registers of the data conversion unit 41,
It will be treated as invalid.

With such a circuit configuration, the compressed data can be surely restored to the original 1 in correspondence with each overwriting mode.
It can be expanded to 6-bit print data.

In the multiplexer 44, each of the above printing modes (two-time overwriting mode, three-time overwriting mode, four-time overwriting mode, six-time overwriting mode).
A select circuit 441 for selecting the 2-pass, 3-pass, 4-pass, and 6-pass selection signal lines 4 is provided.
When the selection signal is input to any of the signal lines 11a to 411d, the data expansion output unit 43 having the AND circuit configuration according to the selection mode is selected (set to the active state).
It is like this.

FIG. 4 shows a circuit configuration in which the circuit block A shown in FIG. 3 is used as one block and a required number of the blocks are arranged so as to correspond to the number of bits of image data of the vertical example of the print head 27. .

That is, since the monochrome (black) has 208 bits in the vertical direction of the image data of the print head 27, the number of circuit blocks A shown in FIG. 3 is 13 (= 20).
8 ÷ 13) Must be arranged in parallel. FIG. 4 is a block diagram schematically showing this arrangement configuration. That is,
Each of the 13 blocks A1 to A13 described as Segment Register in FIG. 4 indicates the data conversion unit 41 shown in FIG.

The compressed data storage unit A42 shown in FIG.
The compressed data storage unit 42 shown in FIG.
1 to A13 are arranged in parallel so that 13 units are arranged in parallel, and in the data expansion output unit A43, 13 units are arranged in parallel in the data expansion output unit 43 shown in FIG. 4 corresponding to each block A1 to A13. It has been configured.

As a result, from the data expansion output unit A43, in accordance with the number of bits of the image data of the vertical example of the print head 27, 208 bits for monochrome (black) and 192 bits for color are output. Is output and held in the hold register A45.

As described above, 16-bit data is treated as one segment (Segment).
In the above, the image data output from the hold register A45 is described as 12 Segment for color and 13 Segment for monochrome (black).

Next, in the printing system having the above configuration,
The compression and decompression process of the print data transmitted from the personal computer 1 to the printer 2 will be specifically described by taking the two-time overwriting mode as an example.

In the personal computer 1, first, the mask pattern data creating section 14 creates mask pattern data corresponding to the designated print mode. Here, it is assumed that the user has designated the overwriting mode twice as the print mode. Therefore, the mask pattern data creation unit 14 creates the first mask pattern data 2P1 in the two-time overwriting mode shown in FIG. 2 and sends it as a command to the printer 2 before sending the compressed data.

Next, in the personal computer 1, the print data stored in the print data storage unit 11 is analyzed by the data analysis unit 12, and the analyzed print data is compressed data creation unit 1
Supply to 3.

The compressed data creating section 13 creates compressed data based on the supplied print data. Ie 1
Two pieces of compressed data are created by thinning out every other print data in the sub-scanning direction. Specifically, looking at one segment (16 bits), the first odd number (1, 3,
5,7,9,11,13,15) bit data is left and even-numbered (2,4,6,8,10,12,14,1)
6) Bit data is thinned out to create odd 8-bit compressed data, and then even-numbered (2, 4, 6, 8, 1)
Bit data of 0, 12, 14, 16) is left, and odd-numbered (1, 3, 5, 7, 9, 9, 11, 13, 15) bit data is thinned out to create even 8-bit compressed data. As a result, each compressed data is the same as the original print data.
It has been compressed to / 2. Then, these compressed data are transmitted to the printer 2.

In the ASIC 21 of the printer 2, the mask pattern data 2P1 previously transmitted as a command is sent.
Is set in 12 registers that store the mask pattern data of the data conversion unit 41, and the selection signal is input to the 2-pass selection signal line 441a of the selection circuit 441, and the AND corresponding to the two-time overwriting mode is set. The data expansion output unit 43 (circuit configuration shown in FIG. 3) of the circuit configuration is activated. The 12-bit mask pattern data 2P1 set in the 12 registers is converted into 16 bits and set in the 16 registers. Ie 1
6 registers (1, 0, 1, 0, ...
・ ・) Will be set. That is, from the top, the odd-numbered registers are set to be valid (1), and the even-numbered registers are set to be invalid (0).

Thereafter, the subsequently transmitted compressed data is temporarily stored in the buffer memory 212 of the ASIC 21. Then, direct transfer control is performed by the DMA controller of the user logic unit 214, and first, the odd-numbered 8-bit data is set in each register of the compressed data storage unit 42.

As a result, the odd-numbered 8-bit data is ANDed with the output of the odd-numbered register indicating the validity (1) of the data conversion unit 41, whereby the odd-numbered signal lines m1, m3, m5. , ..., the original print data is output to m15, and the data conversion unit 41 is invalid (0).
AND with the output of the even-numbered register indicating that the even-numbered signal lines m2, m4, m6 ,.
.., 0 data is output to m16. As a result, the compressed odd-numbered 8-bit data is expanded to the original 16-bit data in which 0 data is inserted in the thinned-out portion. Then, in the print head 27, the first overwriting (printing from only the odd-numbered nozzles) is performed by the 16-bit data.

When the expansion of the odd-numbered compressed data is completed in this way, the mask pattern data stored in the 12 registers of the data conversion unit 41 is then rotated. That is, the 1-bit data stored in each register is moved to the next lower register, and the 1-bit data stored in the lower register is moved to the upper register. As a result, the mask pattern data 2P2 (see FIG. 2) corresponding to the next even-numbered compressed data is stored in the 12 registers.

The 12-bit mask pattern data 2P2 set in the 12 registers in this manner is 1
It is converted to 6 bits and set in 16 registers. That is, (0, 1, 0, 1, ...) Is set in order from the top in the 16 registers. That is, in order from the top, the odd-numbered registers are set to 0 (invalid) and the even-numbered registers are set to 1 (invalid).

Thereafter, the even-numbered 8-bit data is set in each register of the compressed data storage section 42.

As a result, the even-numbered 8-bit data is ANDed with the output of the even-numbered register indicating the validity (1) of the data conversion unit 41, whereby the even-numbered signal lines m2, m4, m6. , ..., the original print data is output to m16, and the data conversion unit 41 is invalid (0).
Is ANDed with the output of the odd-numbered register indicating that the odd-numbered signal lines m1, m3, m5 ,.
.., 0 data is output to m15. As a result, the compressed even-numbered 8-bit data is expanded into the original 16-bit data in which 0 data is inserted in the thinned-out portion. Then, the print head 27 carries out the second overwriting (printing only from the even-numbered nozzles) using the 16-bit data.

In the above description, only the two-time overwriting mode has been described, but other printing modes (three-time overwriting mode, four-time overwriting mode, six-time overwriting mode) are also possible. It can be performed in the same manner as in the two-time overwriting mode.

In the first embodiment, as shown in FIG. 4, the circuit block A shown in FIG. 3 is regarded as one block, and this corresponds to the number of bits of the image data of the vertical example of the print head 27. Although the necessary number (13) is arranged as described above, the circuit block A shown in FIG.
Switching for providing mask pattern data input to the data conversion unit 41, compressed data stored in the compressed data storage unit 42, and 16-bit data output from the data decompression output unit 43 at a predetermined timing. Means (first switching means and second switching means in the claims: not shown) may be provided so as to output as data corresponding to the number of nozzles in one vertical column of the print head 27. With such a configuration, switching means is required, but since it is not necessary to provide 13 circuit blocks A,
The circuit configuration can be simplified as a whole.

[Second Embodiment] In the first embodiment,
Although the data compression and decompression processing in the case of overwriting printing have been described, the second embodiment does not perform overwriting printing but a normal printing operation (printing of one line of the print head is performed by one scan). (Printing operation).

That is, the basic circuit configuration itself is shown in FIG.
Although the circuit configuration is the same as that shown in FIG. 2, the second embodiment does not have the mask pattern data creation unit 14 of the personal computer 1 and the configuration of the user logic unit 214 of the ASIC 21 is different from that of the first embodiment. . However, in the second embodiment, since the compressed data decompression process executed by the user logic unit 214 is performed by software, the circuit configuration of the user logic unit 214 is not shown.

That is, in the second embodiment, the compressed data creation unit 13 of the personal computer 1 compresses the print data for one time by thinning out every other print data (every other row) along the main scanning direction (horizontal direction). Data is created and this is transmitted as one print data. The printer 2 prints the received compressed data dot by dot in the main scanning direction (horizontal direction) continuously for two dots to perform one printing.

That is, the print data of the thinned columns is
The print data in the immediately preceding column adjacent to each other is used for interpolation. With such a configuration, the print image quality itself may be slightly degraded, but the data amount of the print data transmitted from the personal computer 1 to the printer 2 can be halved with an extremely simple data compression technique. Further, even on the printer 2 side, it is possible to develop print data close to the original print data by an extremely simple data development (restoration) technique of printing continuously for 2 dots. Therefore, the circuit configuration becomes extremely simple, and the product cost can be suppressed.

[0076]

According to the printing system of the present invention, the print data for one time is regularly thinned out to be divided into a plurality of compressed data according to the number of overwriting and transmitted. The amount of print data to be transmitted can be reduced. As a result, the ASI of the printer side
The capacity of the memory mounted on C can be made smaller than that of the conventional one, and the memory size can be made smaller accordingly. Moreover, since the amount of data transmitted at one time is reduced, the communication time between the external device and the printing device can be shortened.

Further, by using the mask pattern data, the data can be compressed by a simple method such as regularly thinning out the print data for one time. Therefore, what kind of image is the image to be printed. However, the data can be surely compressed.

Further, the printing device validates the data of the positions not thinned out and invalidates the data of the thinned positions 1
Based on the data conversion means for converting 2-bit data into 16-bit data and the 16-bit data converted by this data conversion means and the compressed data of 8 bits or less,
Since the structure is provided with the data expansion output means for expanding and outputting the original 16-bit print data, compressed data of 8 bits or less can be surely expanded to the original 16-bit print data.

Further, according to the printing system of the present invention, the external device side creates compressed data by thinning out every other print data for one time along the main scanning direction, and prints this for one time. The printer transmits the data as data and prints the received compressed data in dot units continuously for two dots in the main scanning direction, so that the printing device can print once. The amount of print data transmitted from the external device to the printer can be halved. Further, the printing device side can also develop the original print data with an extremely simple data development (restoration) technique. Therefore, the circuit configuration becomes extremely simple, and the product cost can be suppressed.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of a printing system showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a specific example of mask pattern data in each overwriting mode.

FIG. 3 is a circuit block diagram showing a part of an internal configuration of a user logic unit of the ASIC.

FIG. 4 is an explanatory diagram showing a circuit configuration in which a necessary number of circuit blocks shown in FIG. 3 are arranged so as to correspond to a bit number of image data of a vertical example of a print head.

[Explanation of symbols]

1 PC (external device) 2 Printer (printing device) 3 communication cable 11 Print data storage 12 Data analysis section 13 Compressed data creation unit 14 Mask pattern data creation unit 15 Data transmitter / receiver 21 ASIC 22 CPU 23 ROM 24 RAM 25 feed motor 26 Carrier motor 27 print head 211 Communication port (USB) 212 buffer memory 213 CPU 214 User Logic Department 41, A41 data converter 42, A42 compressed data storage 43, A43 Data expansion output section 44 multiplexer 441 Select circuit A45 Hold register

Claims (9)

[Claims] 1. A printing system in which a printing device performs overwriting printing based on print data transmitted from an external device, wherein the external device side regularly thins out print data for one time, Compressed data creating means for creating a plurality of compressed data of 8 bits or less according to the number of times of overwriting, and to show regularity, the data at the positions not thinned out are valid, and the data at the thinned positions are invalid The printer includes a mask pattern data creating unit that creates 12-bit mask pattern data and a sending unit that sends the compressed data and the mask pattern data. Data conversion means for converting to mask pattern data, and compressed data for storing the compressed data of 8 bits or less Data expansion for expanding and outputting the original 16-bit print data based on the storage means and the 16-bit data converted by the data conversion means and the compressed data of 8 bits or less stored in the compressed data storage means. The output means is provided in a number capable of outputting the number of bits corresponding to the number of nozzles in one vertical column of the print head, and the data expansion output means includes 16 signal lines output from the data conversion means, The eight signal lines output from the compressed data storage means are arranged in a matrix, and corresponding to the mask pattern data.
A printing system characterized in that an AND circuit is arranged at each of six intersections and the logical sum of both signal lines is used to expand compressed data of 8 bits or less into original 16-bit print data and output it. . 2. A printing system in which a printing device performs overwriting printing based on print data transmitted from an external device, wherein the external device side regularly thins one print data, While divided into a plurality of compressed data according to the number of overwriting and sequentially transmitted, the mask pattern data showing its regularity is created and transmitted, the printing device, based on the mask pattern data, the received compressed data. A printing system characterized by expanding and printing the original print data. 3. The compressed data is data of 8 bits or less, and the mask pattern data is data for validating data at positions not thinned out and invalidating data at positions thinned out. The printing system described. 4. The printing device validates data at positions not thinned out and invalidates data at positions thinned out 1
Data conversion means for converting 2-bit data into 16-bit data, and based on the 16-bit data converted by this data conversion means and the compressed data of 8 bits or less, the original compressed data of 8 bits or less 4. The printing system according to claim 3, further comprising a data expansion output unit that expands and outputs 16-bit print data. 5. The print according to claim 4, wherein the data conversion unit generates mask pattern data corresponding to another compressed data based on the mask pattern data corresponding to one compressed data. system. 6. The data decompression output means includes 16 signal lines output from the data conversion means, and 8 signal lines output from a compressed data storage means that stores compressed data of 8 bits or less. Are arranged in a matrix form, AND circuits are arranged at 16 intersections corresponding to the mask pattern data, and the logical sum of both signal lines is taken to obtain the original compressed data of 8 bits or less. The printing system according to claim 4 or 5, wherein the printing system develops into bit print data and outputs the bit print data. 7. The data conversion means, the compressed data storage means, and the data decompression output means are provided by a number capable of outputting the number of bits corresponding to the number of nozzles in a single vertical column of the print head. The printing system according to claim 6. 8. A set of the data conversion means, the compressed data storage means, and the data decompression output means are provided, and the mask pattern data input to the data conversion means and the compressed data storage means are stored. First switching means for switching the compressed data at a predetermined timing, and 16-bit data output from the data decompression output means is switched at a predetermined timing and output as data corresponding to the number of nozzles in one vertical column of the print head. The printing system according to claim 6, further comprising a second switching unit. 9. A printing system in which a printing device performs a printing operation based on print data transmitted from an external device, wherein the external device side prints one print data every other one in the main scanning direction. The thinned compressed data is created and transmitted as print data for one time, and the printing device prints the received compressed data for two dots continuously in the main scanning direction in dot units to print one time. A printing system characterized by performing.