JP4946303B2 - Bitmap generation method, printing apparatus, integrated circuit, and bitmap generation apparatus - Google Patents

Description

  The present invention is a bitmap that generates multi-value character data in which one dot is expressed by a gradation value that can be processed by a print engine of a printing apparatus, based on binary character data obtained by horizontally and horizontally reversing characters. The present invention relates to a generation method, a printing apparatus, an integrated circuit, and a bitmap generation apparatus.

  Conventionally, in a printing apparatus, when a character is printed, a character code is sent as print data. Therefore, character data is stored in a ROM or the like so that the character data can be acquired from the character code (for example, Patent Documents 1 and 2). etc). For example, character data is stored in a character generator. When a character code in print data is sent to a character generator, character data corresponding to the character code is given from the character generator. The character data is developed as a bitmap on an output buffer (image buffer) and then sent to a print engine (for example, a print head drive control unit) so that the character is printed according to the bitmap data by the print engine. It has become.

For example, a dot impact printer is provided with character data. In the character data, one dot is expressed in binary (1 bit). On the other hand, recently, inkjet printers that can eject ink droplets in a plurality of sizes have appeared (Patent Documents 3, 4, etc.). In this case, the bit number of 1 dot in the bitmap data is set to 2 bits or more so that the difference in dot size can be expressed by the gradation value in addition to the information of ejection / non-ejection (print / non-print). . For example, in Patent Document 3, one dot is expressed by 2 bits. If “00”, no ejection (non-ejection), “01” is a small dot, “10” is a medium dot, “11”. If there was, it was expressed as a large dot.
JP 2001-138582 A JP-A-5-246078 JP 2004-314411 A JP 2006-095863 A

  By the way, when preparing character data in an ink jet printing apparatus, if character data used in a printing apparatus other than the ink jet printing apparatus (such as a dot impact printer) can be used, the character data is created from scratch. There is no need, and the development speed of the printer can be increased and it is efficient. For this purpose, it is necessary to generate multi-valued bitmap data that can be processed by the print engine based on binary character data, and a suitable method for the generation has been desired.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to use tone data that can be processed by a print engine by using binary character data in which characters are horizontally and horizontally reversed. An object of the present invention is to provide a bitmap generation method, a printing apparatus, an integrated circuit, and a bitmap generation apparatus capable of generating multi-value character data in which one dot is expressed.

  The present invention is based on character data composed of binary bitmap data in which one dot is expressed by binary and the vertical direction of the character is arranged in a direction matching the reading direction and the character is horizontally reversed. A bitmap generation method for generating multi-value bitmap data that can be processed by a print engine of a printing apparatus, wherein the number of bits in the horizontal direction of characters in the character data is a common multiple of eight. The smallest common multiple is selected from the common multiples in which the expansion ratio, which is a value obtained by dividing the common multiple by the horizontal bit number, is equal to or greater than the number of bits representing the number of gradations of one dot that can be processed by the print engine. And performing a multi-value conversion process for converting a binary value representing one dot into a multi-value value representing the number of gradations of one dot that can be processed by the print engine, An expansion step of expanding the character data in the horizontal direction of the character so that the number of bits is equal to the selected common multiple, and the direction of the character in which the horizontal direction of the character matches the reading direction A vertical and horizontal conversion step for rotating the character data by 90 degrees, and a horizontal reversal step for applying a horizontal reversal process for reversing the left and right of the character to the character data, and performing the steps in random order. To do.

  According to this, the number of gradations of one dot that can be processed by the print engine is an expansion ratio that is a common multiple of the number of bits in the horizontal direction of the character and 8 and that is obtained by dividing the common multiple by the number of horizontal bits. The smallest common multiple is selected from the common multiples having a value greater than the number of bits to be expressed. For the selection of the common multiple, a pre-selected one can be set in advance, or a configuration can be calculated and calculated each time. An expansion step, a vertical / horizontal conversion step, and a horizontal reversal step are performed in random order on the binary character data to be processed. In the expansion step, the number of bits in the horizontal direction of the character is equal to the selected common multiple while performing a multi-value conversion process that converts a binary value representing one dot into a multi-value that can be processed by the print engine. As described above, the expansion processing for expanding the character data in the horizontal direction of the characters is performed. In the vertical / horizontal conversion step, the character data is rotated by 90 degrees so that the horizontal direction of the character is the direction of the character that matches the reading direction. In the left / right reversing step, the character data is subjected to left / right reversing processing for reversing the left / right of the character. As a result, binary character data that has been reversed vertically and horizontally (rotated 90 degrees) and horizontally reversed can be converted into multi-value character data that can be processed by the print engine. Moreover, the converted multi-value character data is an array in which the reading direction is the horizontal direction (raster direction) of the character, and the number of bits in the reading direction (the horizontal direction of the character) is a multiple of 8. Can be generated as character data.

  In the bitmap generation method of the present invention, in the expansion step, the selected common multiple represents one dot that can be processed by the print engine, with the expansion magnification being a value obtained by dividing the common multiple by the horizontal bit number. It is preferable to satisfy that it is equal to the number of bits to be performed.

  According to this, if multi-value processing is performed to convert one dot into a multi-value representation that can be processed by the print engine from a binary representation, the number of bits in the horizontal direction of the character is equal to the selected common multiple. The character data is expanded in the horizontal direction of the characters so as to be a number. That is, the character data is expanded in the horizontal direction of the character at an expansion ratio that is a value obtained by dividing the selected common multiple by the horizontal bit number. Therefore, since the multi-value processing also serves as the expansion processing, extra processing other than the multi-value processing is not necessary in the expansion processing.

  In the bit map generation method of the present invention, the character data is a 1-dot bit that can be processed by the print engine with an expansion ratio that is a value obtained by dividing the least common multiple of the number of horizontal bits and 8 by the number of horizontal bits. Preferably, the character data is binary character data having a horizontal bit number that satisfies a condition that matches the number, and in the expansion step, the selected common multiple is a least common multiple.

  According to this, the selected common multiple that defines the number of bits after expansion is the least common multiple and is expanded by the number of bits necessary for conversion into the number of bits of 1 dot that can be processed by the print engine. Therefore, multi-value character data generated by conversion from binary character data can be suppressed to a data size as small as possible.

  In the bitmap generation method of the present invention, in the expansion step, an expansion ratio that is a value obtained by dividing the selected common multiple by the number of horizontal bits is 2 or more in the number of bits of 1 dot that can be processed by the print engine. If the value is a value obtained by multiplying by a natural number, the gradation of dots in the expansion process means no recording at a position corresponding to a position between dots arranged in a multi-value expression in the horizontal direction of the character by the multi-value processing. It is preferable that a process of adding a value is performed.

  According to this, even if the expansion magnification, which is a value obtained by dividing the selected common multiple by the number of horizontal bits, is not equal to the number of bits representing one dot that can be processed by the print engine, the number of bits is a natural number of 2 or more. Can be generated as character data that can be processed by the print engine. That is, in the expansion process, a gradation value of a dot meaning no recording is added at a position corresponding to between multi-value dots arranged in the horizontal direction of the character by the multi-value conversion process. As a result, the generated character data is expressed by multiple values that can be processed by the print engine in one dot, and the character data is expanded in the horizontal direction of the character at an expansion ratio defined by the selected common multiple. Thus, the number of bits in the reading direction (the horizontal direction of the character) is a multiple of eight. In addition, since the gradation value added between the dots means that there is no recording, it is not recorded when the print engine performs the recording process, and only the original dots are to be recorded.

  The present invention is a printing apparatus, a print engine, a character storage unit that can be processed by the print engine and stores multi-value character data generated by using the bitmap generation method of the invention, and A gist is provided with a development processing unit that reads out the multi-value character data from a character storage unit, performs a development process, and sends the developed data to the print engine.

  According to this, multi-value character data generated by using the bitmap generation method of the present invention is stored in advance in the character storage unit in the printing apparatus. Since the multivalued character data read from the character storage unit is character data that can be processed by the print engine, it can be expanded as it is by the expansion processing means, so that the processing prior to transmission to the print engine can be easily completed.

  The present invention is a printing apparatus, comprising: a print engine; a character storage unit that stores the binary character data; the character data is read from the character storage unit; and the bitmap generation method according to the invention is used to read the character data. And a bitmap generation unit that generates multi-value character data that can be processed by the print engine from binary character data, and that develops the multi-value character data and sends it to the print engine. To do.

  According to this, binary character data is stored in the character storage unit in the printing apparatus, and the bitmap generation unit performs the above-described processing based on the binary character data read from the character storage unit. Using the bitmap generation method of the invention, multi-value character data that can be processed by a print engine is generated. The generated multi-value character data is sent to the print engine. In this way, the binary character data can be converted into multi-valued character data in the printing apparatus by using the character storage unit in which the binary character data is stored as it is.

The gist of the present invention is an integrated circuit having an electric circuit section in which a program for executing the bit map generation method of the present invention is formed.
According to this, by using the integrated circuit built in the printing apparatus, even if binary character data is stored in the character storage unit, the binary character data is converted into multi-value character data in the printing apparatus. It becomes possible to convert.

  The present invention is based on character data composed of binary bitmap data in which one dot is expressed by binary and the vertical direction of the character is arranged in a direction matching the reading direction and the character is horizontally reversed. A bitmap generation device that generates multi-value bitmap data that can be processed by a print engine included in a printing device, and is a common multiple of 8 and the number of horizontal bits that are the number of bits in the horizontal direction of characters in the character data. The smallest common multiple is selected from the common multiples in which the expansion ratio, which is a value obtained by dividing the common multiple by the horizontal bit number, is equal to or greater than the number of bits representing the number of gradations of one dot that can be processed by the print engine. And performing a multi-value conversion process for converting a binary value representing one dot into a multi-value value representing the number of gradations of one dot that can be processed by the print engine, Extending means for expanding the character data in the horizontal direction of the character so that the number of bits is equal to the selected common multiple, and the direction of the character in which the horizontal direction of the character matches the reading direction The gist of the present invention is that it includes vertical / horizontal conversion means for rotating the character data by 90 degrees, and left / right reversing means for applying left / right reversal processing for reversing the left / right of the character to the character data. According to this configuration, the same effect as the invention of the bitmap generation method can be obtained.

  Hereinafter, an embodiment of a bitmap generation method and a bitmap generation apparatus embodying the present invention will be described with reference to FIGS. First, a printing apparatus that performs print processing using character data (character data) including multi-value bitmap data generated by the bitmap generation method of the present embodiment will be described.

  FIG. 1 is a perspective view illustrating a basic configuration of a printing apparatus. As shown in FIG. 1, the printing apparatus 11 includes a substantially rectangular box-shaped main body case 12 that is open toward the upper side and the near side in the drawing. A guide shaft 13 having a predetermined length is installed between the left and right side walls of the main body case 12 in FIG. The carriage 14 in which the guide shaft 13 is inserted is provided so as to be movable in the axial direction of the guide shaft 13. An endless timing belt 15 is rotatably supported on the inner back side of the main body case 12 while being stretched in the main scanning direction X, and one position on the back side of the carriage 14 is a predetermined portion of the timing belt 15. It is fixed in place. The carriage 14 is connected to a drive shaft of a carriage motor 16 that rotationally drives the timing belt 15 via the timing belt 15 so that power can be transmitted. The carriage 14 is configured to reciprocate in the main scanning direction X when the carriage motor 16 is driven forward and backward and the timing belt 15 rotates forward and backward.

  An ink jet recording head 17 is provided below the carriage 14, and a lower surface of the recording head 17 is a nozzle formation surface 17 a (both shown in FIG. 3). 3, only one column for one color is shown))). A platen 19 that defines the interval between the recording head 17 and the paper P is provided in the main body case 12 at a position facing the movement path of the recording head 17 during printing. A black ink cartridge 20 that supplies ink to the recording head 17 and a color ink cartridge 21 that individually contains, for example, three colors of cyan, magenta, and yellow are detachable on the carriage 14. Is loaded. Ink is supplied from the ink cartridges 20 and 21 to the recording head 17, and the recording head 17 can eject (discharge) ink from the nozzles 18 on the nozzle forming surface 17a.

  A paper feed motor 22 is disposed at the lower right end of the main body case 12 in FIG. The paper feed motor 22 is driven, and paper feed rollers and paper discharge rollers (not shown) disposed on both sides of the recording head 17 on the paper transport path are driven to rotate. Are conveyed in the sub-scanning direction Y. Then, a recording operation for ejecting ink from the nozzles 18 of the recording head 17 to the paper P while reciprocating the carriage 14 in the main scanning direction X, and a predetermined transport amount (paper feed amount) of the paper P in the sub-scanning direction Y. Printing is performed on the paper P by alternately repeating the paper feeding operation. Note that one end position (the right end position in FIG. 1) on the movement path of the carriage 14 is a standby position (home position) for waiting when the carriage 14 does not perform printing work. A maintenance device 23 that performs maintenance of the recording head 17 is installed at a position corresponding to a position immediately below the carriage 14 disposed at the standby position in the main body case 12.

  FIG. 2 is a block diagram illustrating a basic electrical configuration of the printing apparatus. As shown in FIG. 2, the printing apparatus 11 includes an interface unit 30 (I / F unit), a reception unit 31, an interpretation unit 32, a control unit 33, an image generation unit 34, a character generator 35 (CG-ROM), and a print engine. 37. The print engine 37 includes a print drive circuit 38 that performs ejection drive control of the recording head 17. In addition to the print drive circuit 38, the print engine 37, the carriage motor 16, the paper feed motor 22, and the motors 16 and 22 are driven and controlled. And various motor drive circuits (not shown). The printing apparatus 11 includes a CPU, an ASIC 39 (Application Specific IC), a ROM, and a RAM. The interpretation unit 32 is configured by a CPU that executes interpretation processing, and the image generation unit 34 performs development processing for developing character data (character data) acquired from the character generator 35 and image data acquired from print data on the image buffer 36. The ASIC 39 includes an electronic circuit to be executed. Further, the receiving unit 31 and the image buffer 36 are each constituted by a RAM. Of course, the CPU and the ASIC 39 are configured to perform various other functions including control of the print engine 37.

  Print data input from the host device (not shown) through the interface unit 30 by the printing apparatus 11 is temporarily stored in the reception unit 31 and then sent to the interpretation unit 32. The interpretation unit 32 interprets the print data, separates the print data into a portion including a header and a footer, and print data, and transfers the print data to the image generation unit 34 (ASIC 39). The recording data consists of data including image data and character codes. The image generation unit 34 performs image data expansion processing. Further, the image generation unit 34 acquires character data corresponding to the character code from the character generator 35 by sending the character code to the character generator 35.

  In the present embodiment, the character generator 35 has two configurations depending on the type of character data stored in the character generator 35. That is, the character generator 35 stores binary character data for a dot impact printer, and the character generator 35 stores multi-value character data that can be processed by the print engine 37. There is. The character data for dot impact is composed of binary data in which one dot is expressed in binary (1 bit), and is composed of character data in which characters are arranged in a horizontal direction rotated 90 degrees and characters are reversed left and right. As it is, the inkjet print engine 37 cannot perform processing.

  Therefore, when the character generator 35 has the former configuration, the image generation unit 34 generates multi-value character data that can be processed by the print engine 37 based on the acquired dot impact character data. The ASIC 39 having the image generation unit 34 constitutes an integrated circuit having a circuit unit in which a program capable of executing the bitmap generation method of the present invention is built as hardware in the form of an electronic circuit. On the other hand, when the character generator 35 has the latter configuration, multi-value character data generated based on dot impact character data is stored in the character generator 35 in advance. In this case, the image generation unit 34 performs only a known development process.

  The image generation unit 34 reads out character data from the character generator 35 by sending a character code, and develops it on the image buffer 36. At this time, the image generation unit 34 divides multi-value character data into a plurality of characters in the horizontal direction with a predetermined byte width (in this embodiment, 2 byte width) and reads out the divided data strings in one line. The vertical expansion is performed to expand the character data in order. By this development (vertical development), the character data is arranged in accordance with the ejection order in which ink is ejected from the plurality of nozzles 18 arranged in the sub-scanning direction Y when the recording head 17 moves in the main scanning direction X. Be replaced. The expanded data is serially transferred bit by bit from the image buffer 36 to the print drive circuit 38 of the print engine 37, or is transferred in parallel in a predetermined byte unit (1 byte unit or 2 byte unit). Regardless of the transfer method, the transferred data is stored in a predetermined storage area in the print drive circuit 38 in units of bytes. In the present embodiment, the print engine 37 refers to a discharge processing portion including a print drive circuit 38 that performs print processing (discharge processing) based on character data unless otherwise specified.

  The character data developed on the image buffer 36 by the image generation unit 34 is multi-value bitmap data in which one dot is expressed by 2 bits (4 gradations). The print engine 37, which is the transfer destination of this multi-valued character data, can divide ink droplets in three types of large, medium and small sizes. The configuration is based on gradation values expressed in multiple values. Whether or not ink droplets are ejected and the size (dot size) of the ejected ink droplets are determined according to the tone value of the dots. That is, in multi-valued character data, one dot is expressed by four types of gradation values “00”, “01”, “10”, and “11”. The print engine 37 is configured to be able to process multi-value character data in which one dot is expressed by four gradations. For example, “00” indicates no discharge, “01” indicates a small dot, and “10 "Is a medium dot, and" 11 "is a discharge process that discharges a large dot ink droplet.

  FIG. 3 shows the configuration of the print control circuit. The print drive circuit 38 includes a drive signal generation circuit 40 that outputs a discharge drive signal DS composed of one set (for example, two) of voltage pulses having different voltage waveforms, a shift register 41, a latch circuit 42, a level shifter 43, and a switch element 44. , Each ejection drive element 45 is provided. One ejection driving element 45 is provided for each nozzle 18 of the recording head 17, and in this embodiment, the ejection driving element 45 is constituted by a piezoelectric vibrator. Of course, it is sufficient that the ejection driving element 45 is an element that can be used in an ink jet recording head, and it can be configured using, for example, an electrostatic driving element or a heating element in addition to the piezoelectric vibrator.

  Based on the control signal from the control unit 33, the drive signal generation circuit 40 generates and outputs an ejection drive signal DS in synchronization with the ejection timing when ink is ejected during printing.

  Each shift register 41 has dot data SI (for example, any one of 2-bit gradation value data “00” “01” “10” “11”) synchronized with a clock signal CK from an oscillation circuit (not shown). ) Is entered. Each shift register 41 first sets the upper bit data of the dot data sequentially.

  When the upper bit data is set in each shift register 41, the latch circuit 42 latches the data set in the shift register 41 based on a latch signal LAT input at a predetermined timing.

  When the data is “1”, the level shifter 43 boosts the latched data to a predetermined voltage value (for example, several tens of volts), and the switch element 44 is connected by the boosted data. On the other hand, when the data is “0”, each level shifter 43 does not boost the data, and the switch element 44 is disconnected.

  The switch element 44 receives the ejection drive signal DS shown in FIG. 3 from the drive signal generation circuit 40. The ejection drive signal DS includes a first pulse COM1 and a second pulse COM2. The first pulse COM1 of the ejection drive signal DS is applied to each switch element 44 at the timing when the switch element 44 is connected based on the upper bit “1”. When the upper bit data is output, the dot data is then shifted to the lower bit data, and at the timing when the switch element 44 is connected based on the lower bit “1”, the second pulse COM2 is switched to each switch. Applied to the element 44.

  That is, when dot data of “01” is output, only the second pulse C0M2 of the ejection drive signal DS is applied to the ejection drive element 45, and small dots of ink are ejected. In addition, when the dot data SI of “10” is output, only the first pulse COM1 of the ejection drive signal DS is applied to the ejection drive element 45 to eject the medium dot ink, and the dot data of “11”. When output, both the first pulse COM1 and the second pulse COM2 are applied to the ejection drive element 45, and large dots of ink are ejected. As described above, the voltage pulse selected according to the gradation value of the dot data SI in the ejection drive signal DS is applied to the ejection drive element 45, so that the ejection drive is performed with the intensity according to the applied voltage pulse. The element 45 is driven to discharge, and an ink droplet having a size corresponding to the gradation value is discharged from the nozzle 18. Note that the voltage waveform of the ejection drive signal DS in FIG. 3 is a schematic diagram for explaining a configuration in which ink droplets are divided into large, medium, and small, and the voltage waveform of each pulse and the combination thereof are the ink characteristics ( The ink droplets can be appropriately changed so that the ink droplets can be divided into an appropriate dot size according to the viscosity of the recording head and the ejection characteristics of the recording head.

  Next, a bitmap generation device that is applied to the printing apparatus 11 and generates character data composed of multi-value bitmap data for inkjet based on character data composed of binary bitmap data for dot impact. Will be described. FIG. 4 is a block diagram showing an electrical configuration of the bitmap generation apparatus.

  As shown in FIG. 4, the bitmap generation device 50 includes a main control unit 51, a memory 52, a calculation unit 53, a horizontal inversion unit 54, a vertical / horizontal conversion unit 55, an extension processing unit 56, and an interface 57. The main control unit 51 performs a bitmap generation process for generating character data for ink-jet based on character data for dot impact by instructing the respective units 52 to 57 to perform predetermined processing. The bitmap generation process executed by the main control unit 51 instructing each of the units 52 to 56 is shown in the flowchart of FIG. In this bitmap generation processing, left / right inversion processing, vertical / horizontal conversion processing, expansion processing, and the like are performed. Here, before describing the bitmap generation processing in detail, first, character data for dot impact will be described.

  FIG. 6 shows binary character data. FIG. 6A shows the character data for dot impact, and FIG. 6B shows the character data after the horizontal reversal process. FIG. 6C is a data diagram showing in detail an area (1 byte area) corresponding to 1 升 in the character data in FIGS. 6A and 6B. In FIG. 6 (a) and FIG. 6 (b), the numbers given in the boxes indicate the data reading order (address order).

  The character data CD1 for dot impact shown in FIG. 6A is the character data of the character “A”, and the reading direction (the direction from the left to the right in FIG. ) In the character generator 35 (CG-ROM) with the orientation being the vertical direction of the character and the character being reversed left and right (up and down in FIG. 6A). The vertical direction in FIG. 6 is the nozzle arrangement direction (impact wire arrangement direction in the dot impact printer), and the horizontal direction (left-right direction) is the raster direction that is the direction of the dot row in the main scanning direction X.

  Here, in FIG. 6, the character data CD1 is represented by bits in the vertical direction in the figure, which is the nozzle arrangement direction, and in the horizontal direction (left-right direction) in the figure, which is the raster direction, in bytes. It is expressed. That is, 1 升 of the character data CD1 in the figure corresponds to 1 byte as shown in FIG. 6C, and is composed of 8 bits in which 8 binary data are arranged in the raster direction. The binary character data CD1 in which one dot is expressed by 1 bit is 36 bits in the nozzle arrangement direction (vertical direction in FIG. 6A) and 6 bytes in the raster direction (horizontal direction in FIG. 6A). 48 bits). The number of dots in the vertical and horizontal directions of the character is 48 dots and 36 dots, respectively, and the dot size of the character data CD1 is vertical × horizontal = 48 × 36 dots.

  Here, in the character data CD1 shown in FIG. 6 in which one dot is expressed by one bit (binary value), the number of impact wires of the print head of the dot impact printer is 36 in the sub-scanning direction. Rely on books (36 dots). Thus, the character data CD1 is composed of binary data having an image size of 48 × 36 bits in the vertical and horizontal directions, and the resolution is 360 dpi (dot per inch) (1 inch is 2.54 cm). The area where the character “A” is drawn (gray area) takes the value “1”, and the background area of the character (outline area) takes the value “0”. The character expressed in gray in the character data CD1 shown in FIG. 6 is expressed in units of bytes by expressing the font of the byte in gray when there is a bit of “1” in 1 byte of 1 升. Therefore, the contour of the character has a jagged feeling, but the character that is binary-expressed in actual bit units has a smooth contour.

  Returning to FIG. 4, the configurations of the respective units 53 to 56 configuring the bitmap generation device 50 will be described below in order. The left-right reversing unit 54 performs a left-right reversing process for reversing the character data CD1 to the left and right of the character so as to return the character left-right reversed for the dot impact printer to a character that is not left-right reversed for the ink jet printer. When the left / right reversal processing is performed, for example, the character data CD1 shown in FIG. 6A is converted into regular character data CD2 in which the characters are not reversed left and right as shown in FIG. 6B.

  The vertical / horizontal conversion unit 55 converts the vertical direction of the character data so that the horizontal direction (the vertical direction (nozzle arrangement direction) in FIG. 6) is the reading direction (the horizontal direction (raster direction) in FIG. 6) represented by bytes. The horizontal and vertical conversion is performed by rotating the character 90 degrees by switching the horizontal direction.

  The extension processing unit 56 extends the character data so that the number of bits in a predetermined one of the vertical and horizontal directions of the character data is a predetermined number (a natural number of 2 or more) times the original number of bits. I do. At this time, a binary value (1 bit) representing one dot is converted into a 2-bit value capable of representing four gradations, which is the number of gradations that can be processed by the print engine 37. That is, “0” is converted into “00” and “1” is converted into “11” among 1-bit values representing one dot. This means that when printing characters, the ink droplets are not divided into different sizes, and there are only two ways of discharging or not discharging, which means “00” when not discharging, and when discharging It is set to “11” which means to hit a large dot. Of course, it is not essential to make a large dot when ejecting. For example, “1” may be converted to “10” meaning a medium dot or “01” meaning a small dot.

  The computing unit 53 calculates the number of bits after expansion that the expansion processing unit 56 should expand the number of bits. In the present embodiment, as the value of the number of bits after expansion, the bit number Nb (36 bits in this example) in the vertical direction (character horizontal method) corresponding to the nozzle arrangement direction of the character data CD1 and the bit number of 1 byte. The least common multiple of “8” is calculated. Since the number of bits Nb in the vertical direction of the character data is “36”, the least common multiple “72” of “36” and “8” is calculated as the number of bits after expansion. Of course, when the size of binary character data and the size of multi-valued character data are determined, an operation for setting the least common multiple calculated in advance as the number of bits after expansion and calculating the number of bits after expansion Can be omitted.

  In this embodiment, since the bit number Nb is “36”, the least common multiple of “8” is calculated. The number of gradations that can be expanded to a bit number that is a multiple of 8 so that the reading direction is expressed in bytes after expansion, and one bit that represents one dot when the expansion is expanded is the number of gradations that the print engine 37 represents one dot. It is necessary to obtain the number of bits after expansion that satisfies the condition that can be converted into the number of bits that can represent (2 bits in this example). As in the present embodiment, the number of bits Nb (= “36”) is a multiple of 4 and not a multiple of 8 (that is, a double is a common multiple of 8), and the number of bits representing one dot is When converting from 1 bit to 2 bits (when the number of bits only needs to be doubled), the least common multiple of the number of bits Nb and “8” may be used as the number of bits after expansion.

  However, when there is a possibility that character data other than the character data satisfying the above conditions as in this embodiment may be handled, the following processing is performed. First, the common multiple of the bit number Nb and “8” is sequentially calculated from the smaller one. In the case of the common multiple J, it is determined whether or not the expansion magnification Q, which is a value obtained by dividing the common multiple J by the bit number Nb, matches the bit number K that represents the number of gradations that can be processed by the print engine 37. If the expansion magnification Q and the number of bits K match, the common multiple J at that time is adopted as the number of bits after the expansion processing. On the other hand, if the expansion magnification Q does not match the number of bits K, it is determined whether or not Q> K is satisfied. When Q> K is not established, the next common multiple is changed to the next larger common multiple, and the same processing is performed for the common multiple J. On the other hand, if Q> K is established, the number of bits that can be processed by the print engine 37 can be expanded to a number of bits that exceeds the number of bits necessary to represent one dot. Adopted as the number of bits.

  Next, bitmap generation processing executed by the main control unit 51 by causing the units 53 to 56 to perform processing will be described with reference to the flowcharts shown in FIGS. Similarly to FIG. 6, the character data shown in FIG. 7 is expressed in bytes in the reading direction, which is the horizontal direction in the figure, and the numbers in the boxes indicate the reading order of the data.

  The main control unit 51 performs a bitmap generation process for each character data each time the character data is given. Of course, it is possible to implement a method of performing bitmap generation processing on a plurality of character data at a time while grasping the position and orientation of the processed character. Here, regardless of which method is used, the bitmap generation process will be described focusing on one character data.

  First, in step S1, character data CD1 to be processed is acquired. That is, the character data CD1 is read and written in the work area of the memory 52. For example, character data may be read from the outside into the work area of the memory 52 via the interface 57, or character data previously stored in another storage area of the memory 52 may be read into the work area of the memory 52. In the latter case, the memory 52 may be composed of a ROM or flash memory for storing character data and a RAM or flash memory for a work area, or a character data storage area and a work area in one flash memory. May be provided. For example, as a configuration for reading character data from the outside, there is a configuration in which the character data CD1 is acquired through the interface 57 by sending a character code to the character generator 35 that is communicably connected to the bitmap generation device 50.

  In step S2, the least common multiple of the number of bits Nb in the nozzle arrangement direction (vertical direction) of character data (in this example, “36”) and “8” is calculated. The calculation process of the least common multiple is executed by the calculation unit 53 in accordance with an instruction from the main control unit 51. The least common multiple is calculated as “72”, and this value “72” is temporarily stored in a predetermined storage area of the memory 52. As described above, when the sizes of the character data to be handled and the character data after conversion are determined in advance, the calculation of the step is omitted by calculating and setting the least common multiple “72” in advance. You can also.

  In the present embodiment, since the bit number Nb is a multiple of 4 and not a multiple of 8, and K = 2, the least common multiple of the bit number Nb and “8” is calculated. It is said. Of course, there may be a case where the bit number Nb of the binary character data to be processed is not a multiple of 4, and the bit number K that can represent one dot that can be processed by the print engine 37 is not “2”. In order to cope with such a case, a common multiple J (expansion magnification Q) that satisfies the following two conditions is obtained. That is, (1) a common multiple J (or Q = J / Nb) of the number of bits Nb and “8”, and (2) gradation value expression that can be processed by the print engine 37 when expanded at the expansion magnification Q In other words, the condition Q ≧ K that can ensure the number of bits (= Nb × K) necessary for expressing one dot with K bits is satisfied. That is, a common multiple J (or expansion magnification Q (= J / Nb)) that satisfies the condition J / Nb ≧ K may be determined.

  Specifically, the following processing is executed. First, the common multiple of the bit number Nb and “8” is sequentially calculated from the smaller one. When the first common multiple is calculated, the expansion factor Q obtained by dividing the common multiple J (in this example, “72”) by the number of bits Nb represents the number of bits K (in this example) that can represent the number of gradations that can be processed by the print engine 37. “2”) is determined. If the expansion magnification Q and the number of bits K match, the common multiple J is adopted as the number of bits after expansion. The method for calculating the least common multiple corresponds to the case where the expansion factor Q corresponding to the first common multiple J (that is, the least common multiple) matches K. On the other hand, if the expansion magnification Q does not match the number of bits K, it is determined whether or not Q> K is satisfied. When Q> K is not established, the next common multiple is changed to the next larger common multiple, and the same processing is performed for the common multiple J. On the other hand, if Q> K is satisfied, the number of bits after expansion can be increased to the number of bits exceeding the number of bits necessary to represent one dot with the number of bits K that can be processed by the print engine 37. The common multiple J is adopted. The common multiple J to be adopted is temporarily stored in a predetermined storage area of the memory 52.

  In step S3, a left / right reversing process is performed on the given character data CD1 to reverse the left / right of the character. This left / right reversing process is executed by the left / right reversing unit 54 in accordance with an instruction from the main control unit 51. In the left-right reversal process, the process of exchanging data on both sides of the character in the left-right direction is sequentially performed from both ends inward. As a result, the left and right of the character data CD1 are inverted, and as shown in FIG. 6B, regular character data CD2 in which the characters are not inverted left and right (horizontal direction) is obtained.

  In the next step S4, the character data is subjected to vertical / horizontal conversion / extension processing. This vertical / horizontal conversion processing is executed by the vertical / horizontal conversion unit 55 in accordance with an instruction from the main control unit 51. The horizontally inverted character data CD2 stored in the memory 52 is read in the vertical direction (nozzle arrangement direction) in the storage area of the memory 52, and the read data is read horizontally in the original storage area of the memory 52 (reading direction). Perform the writing process. In the process of the vertical / horizontal conversion process, the read data is written with the writing direction changed by 90 degrees, but before the writing, the read data is extended. The vertical / horizontal conversion process may be a process of reading in the horizontal direction (reading direction) and writing in the vertical direction (nozzle arrangement direction).

  This expansion processing is executed by the expansion processing unit 56 in accordance with an instruction from the main control unit 51. In this expansion processing, first, the value of the least common multiple previously calculated (or preset) is read from a predetermined storage area of the memory 52, and the number of bits in the horizontal direction (raster direction) of the character is set to the read least common multiple. The character data is expanded in the raster direction so that the number of bits is equal. Specifically, multi-value conversion processing for converting 1-bit value (2 values) expressing 1 dot into 2 bits (multi-value) that can be expressed in 4 gradations for character data read in the process of vertical / horizontal conversion processing Apply. In the present embodiment, as shown in FIG. 7B, “0” is converted to “00” and “1” is converted to “11”. “0”, meaning no ejection, is converted to “00”, meaning no ejection at 4 gradations, while “1”, meaning ejection, means ejection with large dots at 4 gradations. Is converted to “11”. Then, the multivalued data is written in the storage area of the memory 52 in the horizontal direction (raster direction) which is different from the read direction by 90 degrees. As a result, as shown in FIG. 7A, the vertical and horizontal directions of the character data are converted so that the horizontal direction of the characters matches the reading direction, and the number of bits in the reading direction (the horizontal direction of the characters) is the original 36 bits. It is expanded to 72 bits (9 bytes), which is twice (36 dots). In the character data after the expansion process, one dot is represented by 2 bits. Therefore, even if the character is expanded at the expansion magnification Q = 2, the number of dots in the horizontal direction of the character is 36 dots and the number of dots is not changed.

  In step S2, the common multiple of the bit number Nb and “8” is calculated sequentially from the smaller one, and the expansion magnification Q, which is a value obtained by dividing the common multiple J by the bit number Nb, is a gradation that can be processed by the print engine 37. When the process of determining whether or not the number of bits K that can represent the number is coincident is performed, the extension process is performed as follows. When the common multiple J when the expansion magnification Q (= J / Nb) matches the number of bits K is used, the character data is expanded in the expansion direction (the horizontal direction of the character in this example), and the number of bits after expansion is the common multiple J. The expansion process is performed so that the value becomes equal to. That is, in multi-value processing, “0” meaning no ejection is converted to a K (= Q) bit value meaning no ejection, and “1” meaning ejection is a large dot (or the maximum dot) ) Is converted into a K-bit value meaning discharge. When the bit number Nb is not a multiple of 8, possible values for Q include “2”, “4”, “6”, and “8”. In addition, when the bit number Nb is a multiple of 8, possible values of Q include two or more natural numbers equal to the value of K (= 2, 3, 4, 5,..., 8). In the case of inkjet, it is difficult to consider use in applications where the number of bits K representing one dot exceeds “8”, so the Q value is set to “8” at the maximum here.

  On the other hand, when the expansion factor Q and the number of bits K do not match and are sequentially changed to a larger common multiple and the common multiple J when Q> K is established for the first time is adopted, “0” "Is converted into a K-bit value meaning no ejection, and" 1 "is converted into a K-bit value meaning ejection with a large dot (or the maximum dot). As a combination of Q and K satisfying Q> K, (Q, K) = (4,2), (4,3), (6,2), (6,3), (6,4), (6, 5), (8, 2), (8, 3)... (8, 7). For the combination of Q and K where Q> K, the extra extended bits ((Q−K) bits) are added at positions corresponding to the dots that originally exist. In this case, even if the number of bits added between dots (Q−K) is not a value that is a natural number multiple of K, the extra bits added when performing the resolution adjustment described later are used as a new resolution adjustment. What is necessary is just to use as a dot (however, a value meaning no discharge), or to perform print processing while thinning out extra bits at the time of recording on the print engine 37 (print control circuit 38) side.

  Further, in the combination of Q and K where Q> K, when Q is a natural number multiple of 2 or more (N times) of K, specifically, (Q, K) = (4, 2) , (6, 3), (8, 2), and (8, 4), (N−1) dots represented by the same K bits are added at positions corresponding to the original existing dots. be able to. Then, the value of the K bit representing (N−1) dots added between the dots is set to a value meaning no ejection (for example, “00”, “000”, “0000”). In this way, gradation expression that can be processed by the print engine 37 can be achieved, and dots are not recorded in the extra extended bits. In particular, when Q = 2K, specifically, when (Q, K) = (4, 2), (6, 3), (8, 4), the positions corresponding to the positions between the originally existing dots are as follows. It is only necessary to add one K-bit value (for example, “00”, “000”, “0000”) meaning no discharge. When extra bits (Q−K) can be added as dot gradation values in this way, it is possible to realize a configuration that does not employ thinning-out processing for thinning out extra bits when printing is performed on the print engine 37 side. Become.

  In step S5, it is determined whether or not processing has been completed for all character data to be processed. If there is unprocessed character data, the processing target is switched to the next character data (S6), and steps S1 to S4 are performed. Execute each process. The processing of steps S1 to S4 is executed for each character data, and when it is determined that the processing has been completed for all the character data in step S5, the bitmap generation processing is terminated. In the present embodiment, step S3 for performing the left / right inversion processing corresponds to the left / right inversion step. Further, the expansion process (multi-value process) in step S4 corresponds to an “expansion step”, and the vertical / horizontal conversion process in step S4 corresponds to a “vertical / horizontal conversion step”.

  In this way, dot impact character data CD1 composed of binary data of 360 dpi is converted into ink jet character data CD3 composed of 360 dpi multi-value data. That is, the bitmap generation device 50 generates character data CD3, which is multi-value bitmap data for inkjet, based on the character data CD1 composed of binary bitmap data for dot impact.

  Incidentally, the bitmap generation apparatus 50 shown in FIG. 4 can be configured by a computer such as a personal computer or a workstation. In this case, the units 51 and 53 to 56 in FIG. 4 are constructed by the CPU of the computer executing the bitmap generation processing program shown in the flowchart of FIG. For example, when the character data CD3 shown in FIG. 7 after the bitmap generation processing is stored in the character generator 35 of the printing apparatus 11 in advance, as described above, the bitmap data generation device 50 is constructed by the computer, and the character data CD1. Is subjected to bitmap generation processing to obtain character data CD3, and the obtained character data CD3 is stored in the character generator 35.

  On the other hand, the bitmap generation device 50 shown in FIG. 4 can also be configured by the ASIC 39, for example. In this case, the ASIC 39 incorporates an integrated circuit portion in which the bitmap generation processing program shown in the flowchart of FIG. 5 is created in the form of an electronic circuit. That is, the integrated circuit unit (that is, the image generation unit 34) built in the ASIC 39 constitutes the bitmap generation device 50 shown in FIG. 4, and includes a main control unit 51, a calculation unit 53, a horizontal inversion unit 54, and a vertical / horizontal conversion unit 55. The expansion processing unit 56 is provided. For example, when character data CD1 for dot impact is stored in the character generator 35 of the printing apparatus 11, the bitmap generation apparatus 50 is constructed by the ASIC 39 as described above. Then, the image generation unit 34 performs a bitmap generation process on the character data CD 1 acquired from the character generator 35 in the printing apparatus 11 to acquire character data CD 3, and develops it on the image buffer 36. In addition, when each character size of binary character data and multi-value character data to be handled is determined, and a configuration in which a predetermined least common multiple (or common multiple) is set in the expansion processing unit is realized, Since the calculation for obtaining the number of bits is unnecessary, the calculation unit can be eliminated.

  In the printing apparatus 11, when the image generation unit 34 acquires the character data CD3 as a result of any of the above processes, the image generation unit 34 performs a resolution adjustment process as necessary. The resolution adjustment process is a process for adjusting the resolution of the character data CD3 to the print resolution of the print engine 37. In this embodiment, since the print resolution of the print engine 37 is set to 720 dpi, the resolution is doubled in the raster direction (reading direction) and the resolution is converted from 360 dpi to 720 dpi. That is, as shown in FIG. 8, there is one dot D1 that originally exists in the raster direction (the left-right direction in the figure) (a black circle in the figure, the value of which is an example of “11” meaning large dot ejection). The resolution is converted from 360 dpi to 720 dpi by adding the dot D2 (white circle in the figure) and setting the value of the added dot D2 to “00” meaning no ejection. Then, the 720 dpi character data CD4 with an increased resolution is developed on the image buffer 36. Note that resolution adjustment that increases the resolution in the nozzle arrangement direction may be performed according to the specifications of the print engine 37.

  The image generation unit 34 performs vertical expansion processing for expanding character data in the vertical direction as expansion processing. The vertical development process is a process of rearranging the data order in accordance with the order in which ink droplets are ejected from the nozzles 18 when the recording head 17 is scanned and printed. FIG. 9 shows the character data after the vertical development process. As shown in the figure, the character data is divided by a predetermined byte width (2 bytes width in this embodiment) in the raster direction (left and right direction in the figure), and parallel to the vertical direction (nozzle arrangement direction) of the character and predetermined bytes. The vertical development process is performed by writing the data string having the width in the vertical direction on the image buffer 36 in order of the character reading direction (raster direction). In FIG. 9, the numbers in 升 in the character data CD5 after the vertical development process indicate the arrangement order of the dot data (however, the horizontal direction in the figure is byte representation), and the 2-byte-width data string divided by the bold line is Actually, the dot data is stored in a vertical row on the image buffer 36.

  As shown in FIG. 9, when the character data is expanded in the vertical direction with a width of 2 bytes, since the width in the raster direction for one character is 9 bytes and an odd byte width, the last write address is the 9th byte. The image generation unit 34 manages the write address to the image buffer 36 with a counter, and when character data having an odd byte width (9 byte width) is written from an odd byte address (for example, the first byte), An address boundary occurs at the trailing edge. Next, for example, when writing the character “B”, since the previous character data is 9 bytes wide, an odd address boundary occurs at the tip. Therefore, the first byte of the character data of the character “B” is the 10 bytes that are the next address so as to form the last write address (9th byte) of the character “A” and a 2-byte wide data string. Write to the byte sequence of the eye. That is, when the address indicating the last written byte sequence when the next character is expanded is the odd number byte, the even number byte sequence obtained by adding “1” to the odd value of the counter is added to the next character data. Start writing from. FIG. 9 shows an example in which character data that has not been subjected to resolution adjustment is developed.

  The data vertically developed in one column on the area of the image buffer 36 for each 2-byte width data column is transferred from the image buffer 36 to the print drive circuit 38 of the print engine 37 in the dot formation order.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) One dot that can be processed by the print engine 37 is the least common multiple of the number of bits Nb in the horizontal direction of the character and “8”, and the expansion magnification Q that is the value obtained by dividing the least common multiple by the number of bits Nb. The least common multiple is set to be equal to the number of bits to be expressed. The binary character data for dot impact is subjected to an expansion step for expanding the character data so that the number of bits is equal to the least common multiple set in the expansion direction, a vertical / horizontal conversion step, and a horizontal reversal step. Multi-valued character data that can be processed with. Therefore, based on binary character data for dot impact, the number of bits in the reading direction (the horizontal direction of the character) is a multiple of 8 in the direction in which the reading direction is the horizontal direction (raster direction) of the character, and 1 It is possible to generate multi-value character data in which dots are expressed as gradation values so that the print engine 37 can process them.

  (2) In the expansion step, the expansion ratio Q (= J / Nb) determined from the common multiple J selected from the common multiples of the number of bits Nb and “8” is the number of bits representing one dot that can be processed by the print engine 37. Equal to “2”. In other words, the selected common multiple J is equal to a value obtained by multiplying the bit number Nb by the bit number “2” representing one dot that can be processed by the print engine 37. Therefore, if a multivalue conversion process is performed in which one dot is converted from a binary expression into a multivalue expression that can be processed by the print engine 37, the character is set so that the number of bits in the horizontal direction becomes the selected common multiple. Data is expanded in the expansion direction (the horizontal direction of characters). That is, since the multi-value processing also serves as the expansion processing, the processing can be reduced.

  (3) When the expansion magnification Q determined from the selected common multiple is a value obtained by multiplying the number of bits representing one dot that can be processed by the print engine 37 by a natural number of 2 or more, multi-value processing is performed in the expansion processing. Thus, the tone value of a dot meaning no recording is added at a position corresponding to the space between dots arranged in a multi-value expression in the horizontal direction (raster direction) of the character. For this reason, even if the expansion magnification Q is not equal to the number of bits K representing one dot that can be processed by the print engine 37, the expansion magnification Q multiplies the number of bits K representing one dot by a natural number of 2 or more. If the value is a character value, character data that can be processed by the print engine 37 can be generated. The generated character data is expressed by a multi-value that can be processed by the print engine 37 for one dot, and the character data is converted to the horizontal direction (raster of the character) with an expansion magnification Q determined from a set common multiple (expansion bit number). The number of bits in the reading direction (character horizontal direction) is a multiple of eight. Moreover, since the gradation value added between the dots means that there is no recording, it is not recorded when the print engine 37 performs the recording process, and only original dots can be recorded.

  (4) The condition that the expansion ratio Q determined from the least common multiple of the horizontal number of bits Nb and “8” as binary character data matches the number of bits K of 1 dot that can be processed by the print engine 37 The character data CD1 having the bit number Nb to be satisfied was adopted. Therefore, the least common multiple can be adopted as the number of bits after the expansion process in the expansion step, and the multi-value character data CD3 generated by conversion from the binary character data CD1 can be suppressed to a small data size as much as possible.

(5) Since the expansion process is performed in the process of the vertical / horizontal conversion process, the number of read / write operations can be relatively reduced, and the bitmap generation process can be executed at a relatively high speed.
(6) The multi-value character data CD3 generated by the bitmap generation method using a personal computer or the like is stored in the character generator 35 in advance, and the multi-value acquired from the character generator 35 by the image generation unit 34 as the expansion processing means. The character data is expanded and sent to the print engine 37. Therefore, since only the multivalued character data acquired from the character generator 35 needs to be expanded in the printing apparatus 11, the processing in the printing apparatus 11 can be completed easily.

  (7) Binary character data is stored in the character generator 35 in the printing apparatus 11, and the bitmap generation method is performed based on the binary character data read from the character generator 35 by the image generation unit 34. A configuration for generating multi-valued character data by using was provided. Therefore, it is possible to acquire inkjet multi-value character data in the printing apparatus 11 using the character generator 35 in which character data for dot impact is stored as it is.

  (8) The ASIC 39 includes an electric circuit unit (integrated circuit unit) in which a program for executing the bitmap generation method of the present embodiment is built. Therefore, by incorporating the ASIC 39 in the printing apparatus 11, the binary character data is converted into multi-valued character data in the printing apparatus 11 that implements the character generator 35 in which the binary character data is stored. Is possible.

In addition, it is not limited to the said embodiment, The following forms can also be implemented.
(Modification 1) In the above embodiment, the dot impact character data has 36 dots (36 bits) in the nozzle arrangement direction (impact wire arrangement direction) in the number of dots (bit number Nb). However, the present invention is not limited to this. . The number of dots (number of bits Nb) in the nozzle arrangement direction in the character data is not particularly limited. The number of bits Nb may be 28, 52, 76, 100 bits, for example. In these cases, the expansion magnification Q determined from the least common multiple of “8” is “2”, which is equal to the number K of bits representing one dot of the multi-value character data, and is the character after being converted to multi-value. The number of bytes in the horizontal direction (reading direction) of the data characters is “7”, “13”, “19”, and “25”, respectively.

  (Modification 2) In the above embodiment, the character data for dot impact is the original data to be processed, but the processing target is not limited to character data for dot impact. In short, binary character data that requires vertical / horizontal conversion, left / right reversal, and expansion processing (multi-value processing) is sufficient to obtain character data that can be processed by the print engine 37 of the printing apparatus 11. If it is such character data, the recording method of the printing apparatus originally applied is not particularly limited. For example, it may be character data for a laser printer.

  (Modification 3) The horizontal reversal step, the expansion step, and the vertical / horizontal conversion step are not limited to the order in the embodiment, and the order can be changed as appropriate. That is, these steps may be performed in any order. In the above-described embodiment, the vertical / horizontal conversion process and the expansion process are performed together. However, although the number of times of reading / writing increases, they may be performed as individual processes. In this case, for example, if the horizontal reversal step is α, the vertical / horizontal conversion step is β, and the expansion step is γ, any of the following orders can be adopted. (First, second, third) = (α, β, γ), (α, γ, β), (β, α, γ), (β, γ, α), (γ, α, β) , (Γ, β, α). Further, the extension process can be performed in the process of the left-right reversal process.

  (Modification 4) In the above-described embodiment, as a configuration for performing the bitmap generation process in the printing apparatus, the bitmap generation apparatus is built in the ASIC 39 as an electronic circuit unit, and the character data CD1 read from the character generator 35 is stored in the ASIC 39. The image generation unit 34 performs a bitmap generation process. Instead, it is also possible to adopt a configuration in which the electronic circuit unit of the bitmap generation device is incorporated in the character generator 35 and multi-value character data after the bitmap generation processing is acquired from the character generator 35.

  (Modification 5) In the above embodiment, the bit map generation method program (FIG. 5) is implemented in the electronic circuit unit in the ASIC 39 by hardware. However, for example, the CPU in the printing apparatus 11 generates the bit map. It can also be realized by software by executing the method program. Furthermore, a bitmap generation device can be realized by cooperation of hardware and software.

  (Modification 6) In the above embodiment, the character data (font data) stored in the character generator 35 is a bitmap font, but it may be an outline font. For example, the bitmap generation method of the present invention can be applied to a bitmap font generated from an outline font by an existing rasterizer as a processing target.

  (Modification 7) In the above embodiment, the present invention is applied to a serial printer that performs printing by alternately performing a printing operation and a paper feeding operation. However, the present invention is not limited to a serial printer. It can also be applied to a page printer. In this case, the present invention can be applied to a laser printer, an ink jet printing apparatus having a line head type recording head having nozzles over the entire maximum sheet width.

Hereinafter, the technical idea grasped | ascertained from the said embodiment and each modification is described.
(1) The bitmap generation method according to any one of claims 1 to 5, further comprising a resolution conversion step of converting the resolution of the character data into a print resolution of the print engine. According to this, the resolution of the character data can be matched with the print resolution of the print engine.

  (2) The common multiple selected in the expansion means is equal to the number of bits representing one dot that can be processed by the print engine, with an expansion ratio obtained by dividing the common multiple by the number of bits in the horizontal direction of the character. The bitmap generation device according to claim 8.

  (3) In the multi-value processing, a value representing no record expressed in binary is converted into a value meaning no record expressed in multi-value, and there is a record expressed in binary The meaning value is converted into a value meaning that there is a recording expressed in multiple values, and the technical ideas (1) and (2) according to any one of claims 1 to 4, Bitmap generation method.

  (4) The vertical / horizontal conversion step and the horizontal / horizontal reversal step perform the corresponding vertical / horizontal conversion processing and horizontal / horizontal reversal processing by writing the read character data in a position different from the read position, and the expansion step includes the vertical / horizontal conversion step. And the technical idea (1) to (5), wherein the character data read in one of the left and right reversing steps is subjected to an extension process before writing. The bitmap generation method according to any one of 3).

1 is a perspective view of a printing apparatus according to an embodiment. FIG. 2 is a block diagram illustrating an electrical configuration of the printing apparatus. FIG. 3 is a block diagram showing an electrical configuration of a print drive circuit. The block diagram which shows the electric constitution of a bitmap production | generation apparatus. The flowchart which shows a bitmap production | generation process. (A) (b) Data diagram showing binary character data, (c) Schematic diagram showing 1 byte. (A) Data diagram showing multi-value character data, (b) Explanatory drawing of multi-value processing. Explanatory drawing of a resolution conversion process. The data figure explaining an expansion | deployment process.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Printing apparatus, 16 ... Carriage motor, 17 ... Recording head, 18 ... Nozzle, 22 ... Paper feed motor, 31 ... Reception part, 32 ... Interpretation part, 33 ... Control part, 34 ... Image generation part as an expansion | deployment process means 35 ... Character generator as a character storage unit, 36 ... Image buffer, 37 ... Print engine, 38 ... Print drive circuit, 39 ... ASIC as an integrated circuit, 45 ... Discharge drive element, 50 ... Bit as bitmap generation means Map generation device 51 ... Main control unit 52 ... Memory 53 ... Calculation unit 54 ... Horizontal reversal unit 55 ... Vertical / horizontal conversion unit 56 ... Extended processing unit J ... Common multiple Nb ... Number of bits as horizontal bit number , K: the number of bits representing one dot that can be processed by the print engine, Q: expansion magnification, CD1, binary character data, CD3: multivalue character data.

Claims (8)

The printing apparatus has character data composed of binary bitmap data in which one dot is expressed by binary values and the vertical direction of the characters is arranged in a direction that coincides with the reading direction and the characters are horizontally reversed. A bitmap generation method for generating multi-value bitmap data that can be processed by a print engine,
An expansion magnification that is a common multiple of the horizontal bit number that is the number of bits in the horizontal direction of the character in the character data and 8 and that is a value obtained by dividing the common multiple by the horizontal bit number is 1 that can be processed by the print engine. A bit that represents the number of gradations of one dot that can be processed by the print engine by selecting the smallest common multiple among the common multiples that are equal to or greater than the number of bits that represent the number of gradations of dots. An expansion process for expanding the character data in the horizontal direction of the character so that the number of bits in the horizontal direction of the character is equal to the selected common multiple while performing a multi-value conversion process for converting the number into a multi-value. Expansion steps to perform,
A vertical / horizontal conversion step of rotating the character data by 90 degrees so that the horizontal direction of the character is the direction of the character matching the reading direction;
A left-right reversing step for performing a left-right reversing process for reversing the left and right of the character on the character data,
A bitmap generation method, wherein the steps are performed in random order.   2. The bitmap according to claim 1, wherein in the expansion step, the selected common multiple satisfies that the expansion magnification is equal to the number of bits representing one dot that can be processed by the print engine. Generation method.   The character data includes a horizontal bit that satisfies a condition that an expansion ratio, which is a value obtained by dividing the least common multiple of the horizontal bit number and 8 by the horizontal bit number, matches the number of bits of one dot that can be processed by the print engine. 3. The bitmap generation method according to claim 1, wherein the character data is binary character data having a number, and in the expansion step, the selected common multiple is a least common multiple. 4.   In the expansion step, when the expansion magnification that is a value obtained by dividing the selected common multiple by the number of horizontal bits is a value obtained by multiplying the number of bits of 1 dot that can be processed by the print engine by a natural number of 2 or more. In the expansion process, a process of adding a tone value of a dot meaning no recording is performed at a position corresponding to a position between dots arranged in a multi-value expression in the horizontal direction of the character by the multi-value process. The bitmap generation method according to claim 1, wherein:   A character storage unit that stores the multi-value character data that can be processed by the print engine and that is generated by using the bitmap generation method according to any one of claims 1 to 4; A printing apparatus, comprising: expansion processing means for reading out the multi-value character data from a character storage unit, performing expansion processing, and sending the expanded data to the print engine.   5. The print engine, a character storage unit that stores the binary character data, the character data is read from the character storage unit, and the bitmap generation method according to claim 1 is used. And a bitmap generation unit that generates multi-value character data that can be processed by the print engine from binary character data, and that develops the multi-value character data and sends it to the print engine. Printing device to do.   5. An integrated circuit, comprising: an electric circuit portion in which a program for executing the bitmap generation method according to claim 1 is formed. The printing apparatus has character data composed of binary bitmap data in which one dot is expressed by binary values and the vertical direction of the characters is arranged in a direction that coincides with the reading direction and the characters are horizontally reversed. A bitmap generation device that generates multi-value bitmap data that can be processed by a print engine,
An expansion magnification that is a common multiple of the horizontal bit number that is the number of bits in the horizontal direction of the character in the character data and 8 and that is a value obtained by dividing the common multiple by the horizontal bit number is 1 that can be processed by the print engine. A bit that represents the number of gradations of one dot that can be processed by the print engine by selecting the smallest common multiple among the common multiples that are equal to or greater than the number of bits that represent the number of gradations of dots. An expansion process for expanding the character data in the horizontal direction of the character so that the number of bits in the horizontal direction of the character is equal to the selected common multiple while performing a multi-value conversion process for converting the number into a multi-value. Expansion means to perform,
Vertical / horizontal conversion means for rotating the character data by 90 degrees so that the horizontal direction of the characters corresponds to the direction of the characters matching the reading direction;
A bit map generating apparatus comprising: a left / right reversing unit that performs left / right reversing processing for reversing the left / right of the character on the character data.

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