JPH10244726A - Serial printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To move a printing head to a printing start position without requiring raster image data to be developed to an image buffer. SOLUTION: The printer has a printing start position memory means 7 storing a printing start position and a printing control means 8. When input printing data are raster image data and printing is designated to be made in one direction, the printing control means 8 carries out a seek operation at a first line. At the same time, the control means 8 stores the printing start position in the memory means 7, and executes printing of image data of a succeeding line and thereafter on the bass of the printing start position stored in the memory means 7. After the printing start position of the first line is stored in the memory means 7, a printing head 12 can be moved to the printing start position while the image data are being developed, that is, before the image data are completely developed to an image buffer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] 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 of the next line.

[0002]

2. Description of the Related Art A serial printer prints by reciprocating a carriage on which a print head is mounted in parallel with a 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 connected to the motor. It is configured to reciprocate at a speed suitable for printing to form dots on a recording medium.

[0003] Since this type of printer involves reciprocating motion, not only does it require a running distance for accelerating the carriage from a stopped state to a speed suitable for printing, but also immediately after the printing of one line, the printing head is ready. Is required to set the print position at the optimum position for starting printing, a so-called seek operation.

[0004]

However, in order to set the print head at the print start position, the print start position of the next line cannot be determined until the print data of the next line has been written to the image buffer. There is a problem that the throughput of the entire printing operation is reduced.

In order to solve such a problem, for example, as disclosed in Japanese Patent Publication No. 4-53187 and Japanese Patent Publication No. 4-63784, a plurality of image buffers which can be switched alternately are provided. During the printing operation of the buffer data, the image data of the next line is developed in the other image buffer, and immediately after the printing operation is completed, the printing of the next line is completed based on the image data of the next line that has been developed in the image buffer. To reduce the non-printing period by performing a seek operation for this purpose.

By the way, full-color printing has become possible by improving the printing quality of the ink jet recording head. However, since image data for three or four colors must be developed for this purpose, an image buffer is formed. An extremely large storage capacity is required as the storage means.

For this reason, a storage means capable of developing one line of image data for three colors or four colors for each color is prepared.
When printing in the monochrome printing mode, the first and second image buffers are configured in the storage means, and when printing a large amount of image data simultaneously, such as in the full-color printing mode, one image buffer is configured for each color. In addition, full-color printing can be performed with a small-capacity image buffer while speeding up monochrome printing.

However, during color printing, there is no image buffer for developing the image data of the next line, so that after the printing of the image data of one line is completed, the image data of the next line is developed in the image buffer. If the user does not wait, the seek operation cannot be performed, and there is a problem that the throughput of color printing is significantly reduced.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a serial printer capable of printing raster image data at high throughput even with a small-capacity image buffer. That is.

[0010]

According to the present invention, there is provided a serial printer capable of performing unidirectional or bidirectional printing by reciprocating a print head. And print start position storage means for storing the image data, and when the input print data is raster image data and unidirectional printing is designated,
Performs a seek operation on the first line, stores the print start position in the print start position storage unit, and executes printing based on the print start position stored in the print start position storage unit for the image data from the next line. And control means for performing the control.

[0011]

The print start position of the first line of the image data is determined by a seek operation to execute printing, and the print start position is stored in the storage means. Instead of waiting, the print head is moved based on the stored print start position while the image data is being developed.

[0012]

Embodiments 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 character buffer or character data sent from a host device, for example, in a monochrome print mode. This is to receive and temporarily store raster image data in a print mode or the like.

Reference numeral 2 denotes print data determination means for determining whether print data in the reception buffer 1 is character data or raster image data.

Reference numeral 3 denotes an image expanding means. When the print data is character data, the bitmap data of the character pattern generating means 4 is used. When the print data is raster image data, the print data is subjected to serial / parallel conversion. The possible data is developed in the image buffer 5.

Reference numeral 6 denotes a buffer switching means which, when printing is performed using a single color of the print head 12 like character data, comprises first and second two image buffers, When the character data of the line and the character data of the next line can be written alternately, and when printing is performed simultaneously using a plurality of colors of the print head 12 like image data, one image buffer is provided for each color. And switches the storage areas so that data of each color can be written.

Reference numeral 7 denotes a print start position storage unit which, in the case of image data, stores a print start position detected by a seek operation of the first line executed when printing the image data.

Reference numeral 8 denotes a print control means for executing a seek operation based on print data developed in the image buffer 5, and storing the print start position of the first line in the print start position storage means 7 during color printing. The printing operation is performed by a carriage motor 11 driven by the carriage control means 9 and a print head 12 driven by the print head driving means 10.

Next, the operation of the device configured as described above will be described.
The 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. 4 will be described with reference to the flowchart of FIG. 2 as an example.

First, when the power is turned on (step
B) The print control means 8 performs initialization processing such as home seek, paper loading, and maintenance of the print head (step b).

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. After making a determination (step E), if the result of the determination is that the data is character data, the printing control means 8 prepares for a printing operation in the bidirectional printing mode.

Next, the print data is developed in the image buffer 5 by the image developing means 3 (step S1).
F). The buffer switching means 6 controls the image buffer 5 by 2
First and second image buffer areas are prepared so that image data for a row can be developed.

The character data on the first line shown in FIG. 4 is developed 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. The character data of the next line is developed in the second image buffer area in parallel with the printing (step
Ta).

When the printing of the first line is completed (step 4), a predetermined length of paper is fed, and the image of the second line, which has been developed in the second image buffer area of the image buffer 5, has been completed. Based on the data, the print head 12 performs a seek operation at the print start position b of the line, and starts printing in the other direction. This seek operation is performed by judging whether the non-printing travel distance in the forward direction or the reverse direction from the printing end position of the first line is shorter.

When this operation is repeated and printing of the character data up to the fourth line is completed (step S), the printing control means 8
Switches the printing mode from bidirectional mode printing to unidirectional mode printing because the print data of the next line is raster image data in response to a signal from the print data determination means 2.

That is, the image buffer 5 is re-divided into three or four regions so that one line of image data can be developed for each color, and color printing can be performed with a small-capacity buffer.

The receiving buffer 1 is provided by the image developing means 3.
When the development of one line is completed using the print data of each color as image data of each color, the print control means 8
The print head 12 is caused to perform a seek operation on the basis of the image data (step (1)).

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. (Stepch).

At the stage when the printing of the first line L1 is completed (step S1), if the print data still exists (step S3), the print data determination means 2 determines whether the raster image data is the next line. (Step). If the result of the determination is that the image data is raster image data, the print control means 8 reads the data of the first line 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).

The image developing means 3 simultaneously moves the print head 12 to the print start position Ps,
The print data of the line L2 is developed as image data of each color in each area of the image buffer 5 (step w), and the raster image data of the next line is printed (step f).

In the following, for the image area, the print head 12 does not wait for the print data to be developed in the image buffer 5 while developing the image data based on the data in the print start position storage means 7. Printing start position P
The operation of moving the image data to the same digit position as s and printing the image data is repeated until the last line Ln of the image data.

When the printing of the raster image data is completed, since the print data of the next line is character data, the printing mode is switched to the bidirectional mode printing, the seek operation is resumed, and the print head 1 is started.
2 is moved to the printing start position e (step Y), and the processing of steps (T) to (G) is repeated until there is no more character data.

As described above, when printing image data, the processing time required for one line in the related art is, as shown in FIG. 5, a seek operation time t1 ', a print operation time t2', and a data write time t3 for the next line. However, in this embodiment, after the printing operation of one line is completed, the operation of writing the print data of the next line to the image buffer and the operation of the print head to the printing start position are performed in this embodiment. Since the movement is performed in parallel, the processing time required for one line can be reduced by the sum of the non-printing running time t1 and the printing operation time t2, that is, the time required to develop the image data.

When the print data of one page is all image data, a seek operation is performed only on the first line, the print start position is stored in the storage means, and all lines below the next line are stored. The print head may be moved to the print start position based on the print start position.

Further, in the above-described embodiment, an example has been described in which the unidirectional mode printing is automatically executed by determining that the image is raster image data based on the printing data. Causes a serial printer that can specify unidirectional mode printing from the outside to execute the specified unidirectional or bidirectional printing without determining the type of print data. Obviously, a similar approach can be taken.

[0035]

As described above, according to the present invention, a print start position storage means for storing a print start position;
If the input print data is raster image data and unidirectional printing is specified, a seek operation is performed on the first line, the print start position is stored in the print start position storage means, and the next line Control means for executing printing based on the print start position stored in the print start position storage means, so that the print start position of the first line of the image data is determined by a seek operation to perform printing. Upon execution, the print start position is stored in the storage means, and thereafter, 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 of the image data in the image buffer. Therefore, the throughput of the entire printing operation can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a serial printer of the present invention.

FIG. 2 is a flowchart for explaining the operation of the above device.

FIG. 3 is a diagram showing timings of a printing start, a carriage operation, and an image developing process of the above device.

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 showing 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 (1)

[Claims] In a serial printer capable of unidirectional or bidirectional printing by reciprocating a print head, a print start position storing means for storing a print start position, and the input print data being raster image data. When printing in one direction is designated, a seek operation is performed on the first line, the printing start position is stored in the printing start position storage means, and image data from the next line onward is stored in the printing start position. Control means for executing printing based on the print start position stored in the means.