JPS61134791A - Font pattern transmission system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a font pattern transfer method, and more particularly, to a high speed and
This invention relates to an easy font pattern transfer method for lm.

[Technical background of the invention and its problems]

In a kanji system, it is required to efficiently output a huge variety of kanji (tens of thousands of characters) using inexpensive hardware. Therefore, when a request is made to output a character that is not implemented on the output device, by having the host transfer the font/pattern, it is possible to output a high-speed display pattern without increasing the capacity. A structure has been proposed that greatly increases the number of character types.

In the above configuration, it is required that the delay time from when a character code is given to when that character is output is as short as possible. However, under one of the common system configurations in which the host and output device are connected via a serial interface, the transfer of font patterns between the host and the output device takes longer than the processing time inside the host or output device. more time is taken,
The above-mentioned delay time tends to become large.

In order to reduce the delay time, it is conceivable to transfer the font pattern as binary data, but in this case, management of the receiving buffer of the output device becomes a problem. In other words, to prevent this receive buffer overflow, ENQ
When attempting to use the /ACK method, a problem arises because ENQ codes cannot be mixed in binary data. In other words, in this case, before starting to send binary data, the byte length information to be sent is added to ENQ and an inquiry is made to the output device. You must immediately decide whether you can afford to accept binary data. Because such complicated processing is required, when transferring long fonts, patterns, and data such as kanji fonts and patterns, the receive buffer usage efficiency may decrease, or the host software and output device firmware and hardware may be affected. It's a burden.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a font pattern transfer method that enables easy transfer of font patterns in the form of binary data over a serial interface without complicated control. .

[Summary of the invention]

In order to achieve the above object, in the present invention, a character code is given to the output device and the output device, and if a corresponding font pattern is not present in the output device, the font pattern is transferred to the output device. A novel font pattern transfer scheme is provided that can be used to and from a host.

That is, if there is a character code string sent from the host to an output device that is not installed in the output device, that character code is sent back to the host. The host reads the font pattern corresponding to the returned character code from its own memory such as a disk, and converts it into a binary format.
Transfer as data to the output device. On the other hand, the output device side is provided with a buffer that temporarily stores this binary data. The amount of data in this buffer is
If J is exceeded, the first code is sent to the host to temporarily interrupt the binary data transfer. Additionally, when the amount of data in the buffer becomes less than another predetermined value as data is subsequently taken from the buffer further into the output device for font pattern processing, the output device sends a request to the host. 2 is sent to restart the interrupted binary data transfer.

[Embodiments of the invention]

Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 is a block diagram showing an example of the configuration of a host and a printer for realizing the font pattern transfer method of the present invention. Note that although a printer is taken as an example of the output device here, it goes without saying that other output devices such as a CRT display may be used.

In FIG. 1, the host IO includes a control device 12, a large font pattern memory 14, and a transmission line 22.2.
An interface 16 with 4 is provided. transmission line 2
2.24 may be compliant with R5232C, for example. Printer 100 is connected via interface 122 to transmission lines 22,24. Data received via interface 122 is sent to interface stage 1.
20 buffers 124.

The conversion stage 140 sequentially reads data from the buffer 124 and inputs it to the analysis section 142. The analysis unit 142 detects a control sequence such as printer status adjustment given by the host IO from this data, and sends an appropriate response back to the host IO or executes an instructed operation.

In addition, the withdrawal analysis unit 142 shown in the flowchart of FIG.
stores the character codes in sequence in the character code buffer 144, also checks whether a font pattern corresponding to each character code exists in the character generator 148, and marks the absent character code with a certain mark. and remember it. After sending the character code of the 1 record, the host 1O checks with the printer 100 whether or not there is an absent character code in the record. In response to this, the analysis unit 14
2 sends the absent character codes together to the host 10.

In response, the host IO transfers the font pattern to the printer 100. For this transfer, for example, if the bit string of the font pattern is encoded with the character code representing the graphic character and then sent, the transfer efficiency will be poor and the delay time until the character is finally output will be long, which is undesirable. . Therefore, in the present invention,
Transfers font patterns in the form of binary data. The font patterns transferred in this manner are stored in the font pattern storage section 146 and sent to the printing stage 160 in the necessary order along with the font patterns from the character generator 14g.

Buffer 124 within interface stage 120 is a ring buffer controlled by buffer controller 126. The buffer control unit 126 manages the storage of data from the host IO into the buffer 124 and the loading of data from the buffer 124 by the conversion stage 140, and also controls the amount of data in the buffer 124 to a certain value (for example, its capacity). A certain code (
(hereinafter referred to as X0FF) to the host IO,
After sending F, when the amount of data in the buffer 124 becomes less than a predetermined value (for example, 20% of its capacity), another code c (hereinafter referred to as XON) is sent to the host. The control unit 12 in the host controls X OF F, (
Transfer of font patterns is interrupted and resumed, respectively, in response to reception of XON.

Each stage of the transfer of a font pattern from the host IO to the printer 100 via the interface control stage 120 will be described using Table 1.

Table 1 Host IO printer 100 (a) Status adjustment → (b) ← Reception 0K (c) Character code data → Transmission (d) ← X0FF (e) Status adjustment → (f) ← Buffer full (g)
← OK (ml) Font pattern → Transfer as binary data (n) Status adjustment → (0) ← Receive 0K (p) Font pattern → Transfer as binary data (q) ← X0FF (r) Status interval Match → (s) ← Buffer full (1)
← Between (a) and rh), the character code string of the l record is sent from the host lO to the printer 100. In (i) to (+), after sending the l record, the printer 100 collects the absent character codes in the record received in response to the request from the host IO and returns them to the host to transfer the font pattern. request. After confirming that the printer 100 is capable of receiving data, the host IO starts transferring the font pattern in the form of binary data. Here, if the font pattern data in the buffer 124 exceeds a certain amount, (9)
As shown in , X0FF is sent to host lO,
0 after confirming the cause of X0FF (b), (s))
, interrupt the transfer. When the data in buffer 124 is sufficiently reduced, the printer sends an XON as shown at rt) to resume the transfer of font pattern data.

Thereafter, the host IO checks whether there are any unprocessed absent character codes remaining in the printer 1001111, C(v), (w)), and starts sending out the character codes for the next character code.

Please note that when transferring fonts, patterns, and data,
In order to indicate the relationship between each absent character code and the font pattern data that is transferred one after another, the corresponding absent character code may be added to the beginning of each font pattern data and then transferred. In implementing the present invention, various other modifications and additions to the conventional technology may be made.

〔Effect of the invention〕

As explained above, according to the present invention, fonts such as kanji, etc.
In adopting a configuration in which a delay in transferring a font pattern is reduced by dynamically providing a pattern to an output device in the form of binary data, buffer management on the output device side can be realized with a simple configuration.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a host and printer that perform font pattern transfer according to the present invention, and FIG. 2 is a flow chart showing the operation of the conversion stage of the printer in FIG. lO: host, 12: control device, 14: large capacity font/pattern memory, 100: printer, 120: interface stage, 124: buffer, 126/buffer control unit, 140:
Conversion stage, 160: Printing stage.

Claims (1)

[Scope of Claims] An output device; a method for providing a character code to the output device, and transmitting the corresponding font pattern to the output device if a font pattern corresponding to the received character code is not present in the output device; In a method for transferring font patterns to and from a host, the output device includes a buffer for temporarily storing data from the host, and a buffer for temporarily storing data from the host; a second code in response to the fact that the data in the buffer has become less than a second predetermined value, which is less than the first predetermined value;
means for transmitting the corresponding font pattern to the output device as binary data, and in response to receiving the first and second codes, the host transmits the corresponding font pattern to the output device as binary data. - A font/pattern transfer method that is characterized by suspending and resuming data transfer.