JP3861940B2 - Serial printer and printing control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a serial printer, and more particularly to a print control technique for quickly moving a print head to a print start position on the next line.
[0002]
[Prior art]
A serial printer prints by reciprocating a carriage with a print head parallel to the platen by a motor. The carriage is connected to the motor via a transmission mechanism such as a timing belt, and the print head is suitable for printing. Are reciprocated to form dots on the recording medium.
[0003]
Since this type of printer involves reciprocation, not only does it require a run-up distance to accelerate the carriage from a stopped state to a speed suitable for printing, but also the print head starts printing immediately after the completion of one line of printing. Therefore, a so-called seek operation is required.
[0004]
[Problems to be solved by the invention]
However, in order to set the print head at the print start position, since the print start position of the next line cannot be determined until after the print data of the next line is written to the image buffer, the throughput of the entire printing operation is reduced. There's a problem.
[0005]
In order to solve such a problem, for example, as shown in Japanese Patent Publication No. 4-53187 and Japanese Patent Publication No. 4-63784, a plurality of image buffers that can be switched alternately are provided, and data of one image buffer is provided. The image data of the next line is expanded in the other image buffer during the printing operation, and immediately after the printing operation is completed, the seek for printing the next line is performed based on the image data of the next line that has been expanded in the image buffer. It has been proposed to reduce the non-printing period by operating.
[0006]
By the way, full-color printing has become possible by improving the printing quality of the ink jet recording head. To this end, it is necessary to develop image data for three colors or four colors, and as a storage means constituting the image buffer. An extremely large storage capacity is required.
[0007]
For this reason, storage means capable of developing three or four colors of one line of image data for each color is prepared, and the first and second image buffers are configured in the storage means when printing in the monochrome print mode. Also, when printing a large amount of image data at the same time as in the full-color printing mode, etc., one image buffer is configured for each color, so that full-color printing can be performed with a small capacity image buffer while speeding up monochrome printing. It is possible.
[0008]
However, when printing in color, there is no image buffer for developing the image data for the next line. After printing the image data for one line, it is necessary to wait for the image data for the next line to be developed in the image buffer. There is a problem in that the operation cannot be performed and the throughput of color printing is significantly reduced.
[0009]
The present invention was made in view of such problems, and an object is to provide a serial printer capable of printing at high have throughput in the image buffer of the smaller volume.
Another object of the present invention is to propose a printing control method for a serial printer that can perform printing with high throughput even with a small-capacity image buffer.
[0010]
[Means for Solving the Problems]
That is, in order to achieve such a problem, the invention of claim 1 is a serial printer that performs printing by reciprocating a print head, and a print start position obtained from print data on the first line stored in an image buffer. A print start position storage means for storing the print start position storage means when the print data determination means determines that the data in the image buffer is a raster image at the stage when the print operation for the first line is completed. and control means for moving the print head to the print start position on the basis of the data, Ru comprising a.
According to a third aspect of the present invention, in a serial printer that performs printing by reciprocating the print head, the serial printer includes a print start position storage unit that stores a print start position, performs a seek operation only in the first line, and performs the seek operation. Is stored in the print start position storage means, and a printing operation for the next line and thereafter is executed based on the print start position stored in the print start position storage means.
Furthermore, the invention of claim 4 is a serial printer print control method for executing printing by reciprocating the print head, storing a print start position obtained from the first line print data stored in the image buffer, A step of moving the print head to the stored print start position when it is determined that the data in the image buffer is a raster image at the stage where the print operation for the first line is completed.
[0011]
[Action]
According to the first and fourth aspects of the present invention, the print start position of the first line of the image data is determined by the seek operation and the print is executed, and the print start position is stored in the storage means. The print head is moved based on the stored print start position during the development of the image data without waiting for the completion of the development of the data to the image buffer.
The invention according to claim 3 executes the seek operation only for the first line, detects the print start position, stores it, and makes the subsequent seek operation unnecessary.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Therefore, examples of the present invention will be described below.
FIG. 1 shows an embodiment of a serial printer according to the present invention. In FIG. 1, reference numeral 1 denotes a reception buffer, which is a reception buffer and is sent from a host device, for example, character data or color in a monochrome print mode or the like. Raster image data in the print mode or the like is received and temporarily stored.
[0013]
Reference numeral 2 denotes print data determination means for determining whether the print data in the reception buffer 1 is character data or raster image data.
[0014]
Reference numeral 3 denotes image development means. When the print data is character data, the bit pattern data of the character pattern generation means 4 is printed. When the print data is raster image data, the printable data is serial-parallel converted. Is developed in the image buffer 5.
[0015]
Reference numeral 6 denotes a buffer switching means, and when printing is performed using a single color of the print head 12 like character data, the first and second image buffers are constituted to form one line of characters. When data and the next line of character data can be written alternately, and when printing using multiple colors of the print head 12 at the same time as image data, one image buffer is configured for each color. Thus, the storage area is switched so that the data of each color can be written.
[0016]
Reference numeral 7 denotes a print start position storage means for storing the print start position detected by the first-line seek operation executed when the image data is printed.
[0017]
Reference numeral 8 denotes a print control means that performs a seek operation based on the print data developed in the image buffer 5 and stores the print start position of the first line in the print start position storage means 7 during color printing, The carriage motor 11 driven by the control means 9 and the print head 12 driven by the print head drive means 10 are caused to perform the printing operation.
[0018]
Next, the operation of the apparatus configured as described above will be described with reference to an example of print data in which the character data areas A1 and A2 and the image data area B are mixed on the same page as shown in FIG. It demonstrates based on the flowchart of these.
[0019]
First, when the power is turned on (step i), the print control means 8 performs initialization processing such as home seeking, paper loading, and print head maintenance (step b).
[0020]
When a print start command is output from the host device (step c) and print data is input to the reception buffer 1 (step d), the print data determination means 2 determines whether the print data is raster image data ( Step e) If the result of determination is character data, the print control means 8 prepares for a print operation in the bidirectional print mode.
[0021]
Next, the print data is developed in the image buffer 5 by the image development means 3 (step F). The buffer switching means 6 prepares first and second image buffer areas so that the image buffer 5 can develop two lines of image data.
[0022]
The character data of the first line shown in FIG. 4 is expanded in the first image buffer area, and the print head 12 is sought to the print start position a (step Y) to start printing in one direction. At the same time, the character data of the next line is developed in the second image buffer area (step data).
[0023]
When the printing of the first line is completed (step step), a predetermined length of paper feed is executed, and based on the image data of the second line that has been developed in the second image buffer area of the image buffer 5 Thus, the print head 12 performs a seek operation at the print start position b of the line, and printing is started in the other direction. This seek operation is performed by determining which of the forward direction and the reverse direction from the printing end position of the first line is shorter in the non-printing travel distance.
[0024]
When this operation is repeated and the printing of the character data up to the fourth line is completed (step S), the print control means 8 prints because the print data on the next line is raster image data in response to a signal from the print data determination means 2. Switches the mode from bidirectional mode printing to unidirectional mode printing.
[0025]
In other words, the image buffer 5 is divided into three or four areas so that one line of image data can be developed for each color, thereby enabling color printing with a small capacity buffer.
[0026]
When the image development unit 3 finishes developing one line using the print data in the reception buffer 1 as image data of each color, the print control unit 8 performs a seek operation on the print head 12 based on the image data in the image buffer 5 (step t ).
[0027]
The print control means 8 stores the print start position Ps in the print start position storage means 7 and then outputs the image data of the image buffer 5 to the print head 12 to print one line of image data. (Step Chi).
[0028]
When printing of the first line L1 is completed (step), if there is print data continuously (step nu), the print data determination means 2 determines whether it is raster image data of the next line. (Step). As a result of the determination, in the case of raster image data, the print control means 8 reads the first line data stored in the print start position storage means 7, and after feeding the paper, moves the print head 12 to the print start position of the first line L1. Move to the same digit position as Ps (Step E).
[0029]
In parallel with the movement of the print head 12 to the print start position Ps, the image expansion means 3 expands the print data of the second line L2 of the reception buffer 1 as image data of each color in each area of the image buffer 5 ( Step A) Print the raster image data of the next line (Step A).
[0030]
Hereinafter, for the image area, without waiting for the print data to be developed in the image buffer 5, the print start position on the print head 12 during the development of the image data based on the data in the print start position storage means 7. The operation of moving to the same digit position as Ps and printing the image data is repeated until the last line Ln of the image data.
[0031]
When the raster image data is printed, the next line print data is character data, so the mode is switched to bidirectional printing, the seek operation is resumed, and the print head 12 is moved to the print start position e (step Y). Thereafter, the processing of steps (T) to (G) is repeated until there is no character data.
[0032]
Thus, when printing image data, the conventional processing time required for one line is the sum of seek operation time t1 ′, printing operation time t2 ′, and data writing time t3 ′ for the next line as shown in FIG. In contrast to the time required, in this embodiment, after the printing operation for one line is completed, the writing operation of the print data for the next line to the image buffer and the movement of the print head to the print start position are performed. Since the processing is performed in parallel, the processing time required for one line can be shortened by the sum of the non-printing travel time t1 and the printing operation time t2, that is, the time required for developing the image data.
[0033]
If the print data for one page is all image data, the seek operation is executed only for the first line, the print start position is stored in the storage means, and the print start positions stored for all lines below the next line are stored. Based on the above, the print head may be moved to the print start position.
[0034]
In the above-described embodiment, an example has been described in which raster image data is determined based on print data and unidirectional mode printing is automatically performed. A serial printer capable of specifying the directional mode printing performs the specified unidirectional or bidirectional printing without determining the type of print data, and the same method as described above for the unidirectional mode printing. It is clear that
[0035]
【The invention's effect】
As described above, according to the present invention, the print start position of the first line of the image data is determined by the seek operation and the print is executed, and the print start position is stored in the storage means. Since the print head can be moved to the print start position during the development of the image data without waiting for the completion of the development in the image buffer, the throughput of the entire printing operation can be improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of a serial printer of the present invention.
FIG. 2 is a flowchart for explaining the operation of the apparatus.
FIG. 3 is a diagram showing timings of printing start, carriage operation, and image development processing of the apparatus.
FIG. 4 is an explanatory diagram showing an example of print data in which a character data area and an image data area are mixed on one page.
FIG. 5 is a diagram illustrating timings of printing start, carriage operation, and image development processing in a conventional serial printer.
[Explanation of symbols]
2 Print data determination means 5 Image buffer 7 Print start position storage means 8 Print control means 9 Carriage control means

Claims (3)

In a serial printer that performs printing by reciprocating the print head,
Print start position storage means for storing a print start position obtained from print data of the first line stored in the image buffer;
When the print data determination unit determines that the data in the image buffer is a raster image at the stage when the printing operation for the first line is completed, the print start position is set based on the data in the print start position storage unit. Control means for moving the print head;
Serial printer equipped with.   The serial printer according to claim 1, wherein the print data of the next line is written in the image buffer in parallel with the movement of the print head to the print start position stored in the print start position storage means. In the printing control method of a serial printer that performs printing by reciprocating the print head,
Storing a print start position obtained from print data of the first line stored in the image buffer;
A step of moving the print head to the stored print start position when it is determined that the data in the image buffer is a raster image at the stage when the printing operation of the first line is completed;
A printing control method for a serial printer.

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