JPH01290455A - Buffer processing device of dot printer - Google Patents

Abstract

PURPOSE:To obtain a buffer processing device, of a dot printer, which consists of a small number of buffer memories without any decrease of operative efficiency by providing a means to count the residual value of data saved in an image buffer that decreases by the value of data used for the generation of a dot image in an initialized state and increases by the value of data transferred to a printing mechanism. CONSTITUTION:A control circuit B initializes pointers G, H which indicates an image buffer area L and a counter for the residual amount of data saved in the image buffer, then retrieves data from a host computer through an external interface E. However, the circuit stores printing character codes in an area for control J. Next, when the system is set in the printing start control code mode, all character codes stored in the area for control are converted to a printing image, and at the same time, a residual value counter is decremented by the amount of data used from the buffer each time a single character image is stored. However, if single image areas run short while the above-described process is repeated, the control circuit drives a printing mechanism to increment the counter for the residual amount of data saved in the image buffer regarding an image buffer area whose drive is completed. Consequently, the total amount of data saved in the image buffer can be efficiently used continuously with high efficiency without temporary suspension of printing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dot printer having an image buffer for preprocessing a dot pattern to be printed.

[Conventional technology]

A print dot image buffer (hereinafter referred to as an image buffer) developed by a dot printer has conventionally been configured to include image buffers for a maximum number of print digits for a plurality of lines. While a dot image to be printed is transferred from one image buffer among the plurality of lines to the print head with driving of a print mechanism, a dot image of the next line to be printed is transferred to an image buffer other than the one currently being transferred. Use a means to generate it. By terminating the image buffer processing before the end of the dot image transfer, it is possible to drive the print mechanisms one after another in succession, thereby achieving high printing efficiency.

For example, you can create an image buffer that has two image buffers and print the next line in the other image buffer that is currently printing, and then switch the image buffer to be printed at the end of printing and start printing. Manipulate back.

(Problem to be solved by the invention) However, the above-mentioned H
D! In this case, a capacity corresponding to the maximum number of print digits for at least two lines is required. In addition, there is an image buffer 7 memory that is not used when printing with a digit width that does not reach the maximum number of digits.
When printing a digit followed by printing the maximum number of digits, it may be impossible to generate a dot image of the maximum number of digits within the printing time of one digit, which may reduce printing efficiency.

In addition, in the external character definition function, printing efficiency may be reduced by providing an additional memory for storing definition patterns, or by using one of multiple image buffers for storing external character definition patterns. is inviting.

Therefore, the present invention solves these problems,
The purpose is to allocate external character definition patterns in as much buff 77 memory as possible and use the remaining part as an image buffer with a circular structure. Buffer processing H of a dot printer consisting of 7 buffer memories
The goal is to provide a.

[Means to solve the problem]

The buffer processing device of the present invention divides all the buffer 7 memories in which dot links are stored into a fixed length buffer 7 for function control, a custom character buffer whose length is variable according to the amount of defined custom characters, and the two buffers mentioned above. It consists of a circular image buffer with a variable length according to 14ffi of 7, and a definition pattern end pointer that can be rewritten according to the amount of defined external characters and a start or end pointer of the circular image buffer are composed of the same pointer, and the initial The present invention is characterized in that there is a means for counting the remaining capacity of the image buffer 7 which indicates the image buffer length in the state and decreases by the amount of dot image generation and increases by the amount transferred to the printing mechanism.

[Effect]

With the above configuration, the present invention uses all available image buffer lengths when various numbers of printing digits are mixed, and does not provide one buffer area exclusively for definition when one external character definition a function is used.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a buffer processing device of the present invention. Control circuit B1 including a microprocessor unit that controls the entire device on system bus A
All buffers possessed by the device RAM C1 Storage section for character patterns other than external characters D1 Interface section E1 for receiving data from the host computer Mechanism drive section F1 for printing Also buffer y A circular image buffer in RAM Start pointer G1 Also end pointer A remaining amount counter 1 indicating the upper 1 image buffer usage aft is connected. Also, the buffer yRAM, C' is the control area J1
1 image buff in external character definition pattern storage area
Consists of i @ L.

Next, the operation of this embodiment will be explained based on the flowchart shown in FIG. First, as in process [1], the control circuit B initializes the pointer G pointing to the image buffer yflJ area, the month, and the image buffer usage remaining amount counter I. Next, data from the host computer is retrieved from external interface E. Next, in accordance with steps [3] and [4] to determine the extracted data, the process branches depending on the print start code, external character definition code, or print character code.

First, in the case of a printed character hood, the printed character code is stored in the control area J according to process (5).

If character codes follow, multiple characters are stored in the same way.

Next, in the case of the print start control code, process [6] to [13]
], all the character codes stored in the control area as described above are ffm'd to the print image. At the same time, every time an image of a - character is stored, the buff yH1k counter is decremented by the used buffer 1m as in process [11]. While repeating the above, the remaining buffer capacity decreases, and it is determined that the image area for -characters becomes insufficient (7), (8)
) to start the printing mechanism. When the printing mechanism is driven (processing (8), (9)), processing (1)
7), according to (18), increase the buff7FA amount counter for the image buffer area for which driving has been completed. That is, in (8) and (9), processing (17) and (18)
will be carried out. Therefore, the repetition of returning from judgment [7] to [8] will eventually flow from judgment [7] to processing (10) as the mechanism drive progresses, and once all character codes have been converted to images, the next line Return to [2] for processing.

Also, when it is determined that the external character definition control code is received, as shown in [14], it waits until all unprinted areas in the image buffer are finished. When finished, the buffer device has returned to the image buffer length, so at this time process [15]
After storing the external character definition pattern from [16],
Update the circular start pointer to the newly defined pattern end point.

The above embodiment will now be described in more detail. When the external character definition control code is sent in step t) in process [4] of FIG. For example, if the amount of data for one non-standard character is fixed, this image data amount is sent as data for the number of characters of the non-standard character. Since the external character pattern area K is determined based on the amount of image data, the start pointer G is set to the next address of the area. Also, here, the next address in the area is set as the start position, but the order in which the images are developed may be reversed and this position may be set as the end position.

Also, by setting the external character pattern area K, the area for the image buffer area is extremely small (for example, 1B
). In such a case, the printing process becomes difficult, so to avoid this situation, for example, set an upper limit on the capacity of the external character pattern area that can be set, so that it does not exceed a certain size. It is possible that Further, if the area becomes too small, it is also possible to enlarge the area of L.

Further, although the above embodiment has been explained in terms of non-standard characters, the present invention is not limited to only non-standard character patterns, but also includes the setting of areas related to special processing independently set by the user.

〔Effect of the invention〕

As described above, according to the faW of the present invention, the total buffer area can be used continuously and with high efficiency without any temporal interruption in printing.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a buffer device for a printer according to the present invention. FIGS. 2(a), (b)<C) are flowcharts of the above embodiment. Applicant Seiko Epson Co., Ltd. Agent Patent Attorney Kizobe Suzuki and 1 other person CH System bus
~A Figure 1 Figure 2 (b) 2] D [18]

Claims (1)

[Claims] In a dot printer that has an image buffer that stores dot patterns to be printed in advance, and the capacity of the image buffer is at least larger than the maximum defined amount of custom characters, the custom character pattern is stored in the image buffer according to the defined amount of custom characters. A buffer processing device for a dot printer, comprising means for storing a non-standard character pattern in the image buffer, and means for determining that the area is used when a custom character pattern is stored in the image buffer, and changing the operation of the image buffer.