JP2942118B2 - Output control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to
The present invention relates to an output control method capable of converting character pattern information configured by a storage method other than a dot matrix into a dot matrix format.

[0002]

2. Description of the Related Art Conventionally, among output devices, many output devices other than a character printer output characters in a dot pattern. Character code data supplied from a host computer or the like is previously converted into a character pattern by a character generator. The data is developed and output to the frame buffer memory (image memory for one page).

[0003] The manner in which character pattern information is held in a character generator can be broadly classified into the following three. A font in which a character pattern is composed of a simple dot matrix itself (unprocessed) (hereinafter collectively referred to as a “dot matrix font”). A font in which character circles and strokes are stored at coordinate points with respect to the character origin (hereinafter, “ Vector font (outline font) ”.) A font composed of a dot matrix pattern processed using some compression technology (for example, run length) (hereinafter, generally referred to as“ compressed font ”).

[0004] Among them, the "dot matrix font" most used in the conventional output device is the "dot matrix font". The reason is that the character pattern itself is stored in the form of a dot matrix, so that the development into the frame buffer memory is easily performed at high speed.

However, as output devices have become more sophisticated and higher resolution, rotation and deformation of characters have been required, and so-called "vector fonts" have begun to be generally used. In addition, "compressed fonts" are being used as a measure for increasing the capacity of fonts resulting from higher resolution. More recently, even these mixed types have appeared. All of these are referred to as "non-dot matrix type" fonts. Although "non-dot matrix type" fonts have advantages not found in "dot matrix type" fonts, they generally have a frame buffer memory compared to simple "dot matrix type" fonts. There is a disadvantage that it takes a lot of time to develop a character pattern into a character pattern.

[0006]

Objective: When starting up a device, character pattern information constituted by a storage method other than a dot matrix can be converted into a dot matrix format, while the character pattern can be deleted according to the state of the memory. It is an object of the present invention to provide an output control method which can be performed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view showing the internal configuration of a laser beam printer (hereinafter, also referred to as LBP) according to an embodiment of the present invention. The laser beam printer shown in FIG. 1 is capable of registering a character pattern and a fixed format (form pattern) from a data source (not shown). In the figure, reference numeral 100 denotes an LBP main body which converts character information (character code), form information (form code), and the like supplied from an externally connected host computer (not shown) into corresponding character patterns, form patterns, and the like. An image is formed on a sheet as a recording medium. Reference numeral 300 denotes an operation panel on which switches for operation, an LED display, and the like are arranged. Reference numeral 101 denotes a printer control unit that controls the entire LBP 100 and analyzes character information and the like supplied from a host computer. The printer control unit 101 mainly converts character information into a video signal of a corresponding character pattern and outputs the video signal to the laser driver 102. The laser driver 102 is a circuit for driving and controlling the semiconductor laser 103, and turns on / off the laser light 104 emitted from the semiconductor laser 103 in accordance with the input video signal.
Switch off. The laser beam 104 is oscillated in the left-right direction by the rotary polygon mirror 105 and is irradiated on the electrostatic drum 106, on which a latent image of a character pattern is formed.
This latent image is stored in a developing unit 107 around the electrostatic drum 106.
And then transferred to paper. Cut sheet paper is used as the paper, and the cut sheet paper is stored in a paper cassette 108 mounted on the LBP 100,
9 and transport rollers 110 and 111, and are supplied to the electrostatic drum 106.

FIG. 2 shows a configuration example of a control system of the output device of the present invention.

The control system according to the configuration shown in the drawing is for inputting character code data and a control command sent from a print information generating source, and printing by a printing mechanism such as a laser beam printer for printing a document for each page. An example is shown. Here, reference numeral 201 denotes a print information generation device that generates character code data and control commands. Reference numeral 202 denotes an input interface unit including a receiving interface circuit for receiving character code data and a control command generated from the print information generating apparatus 201, and 203 includes a RAM for temporarily storing the character code data and the control command. Input buffer memory.

Reference numeral 204 denotes a built-in character pattern generator which stores the most commonly used character font patterns.

Reference numeral 205 denotes a detachable character pattern generator which is detachable from the main body printer separately from the built-in character pattern generator 204 mounted as standard.
Each of the ROMs 204 and 205 includes a ROM for storing a character pattern compressed and encoded using the run-length technique, and a control circuit therefor, and has a so-called code conversion function of calculating the address of each character pattern from character code data. . Reference numerals 206 and 207 denote sockets for mounting the detachable character pattern generator on the apparatus main body.
The left socket is the left socket 206, and the right socket is the right socket 212.

A font cache memory 207 stores and stores a character pattern obtained by decoding a compression-encoded character pattern into an unprocessed dot matrix pattern.

By storing the decoded character pattern in the font cache memory, it is not necessary to decode the character once used again, and high-speed printing is possible.

Reference numeral 208 denotes a general-purpose microprocessor for controlling the entire control unit, which has a built-in ROM and controls the entire control system in accordance with a program stored in the ROM.

Reference numeral 209 denotes a frame for one page composed of a RAM for developing a character pattern from the character pattern generator into an appropriate position in accordance with a print position command from the host computer. It is a buffer memory. An output interface unit 210 generates a video signal according to the dot pattern information from the frame buffer memory 209 and interfaces with the page printer printing unit 211.
A page printer receives a video signal from the output interface unit 210 and prints image information based on the video signal. Reference numeral 101 denotes a CPU board on which the present control mechanism is mounted.

FIG. 3 is a diagram for explaining the actual storage method of "dot matrix font" and "non-dot matrix font" in the embodiment of the present invention. FIG. 5 is a view visually showing that an image portion of “*” in a character pattern is formed in black, and an image portion of “•” is not formed.
This character pattern has a configuration of 32 dots wide and 32 dots high.

As will be described later, the "non-dot matrix font" may use a method of expressing the outline of a character by using coordinate values or direction difference codes and compressing and encoding (for example,
Japanese Patent Application No. 60-222939).

(B) describes in hexadecimal the contents of a memory when a character pattern visually represented as in (a) is stored in the form of a raw "dot matrix pattern" in ROM or RAM. In the portion where a black image is formed, the corresponding bit is "ON", and in the portion where no image is formed, the corresponding bit is "OFF".
Also, if the character (a) is stored in the form of a "dot matrix pattern", it can be seen that 128 bytes of memory are required. In this embodiment, the character pattern stored in the font cache memory 207 is in this form.
FIG. 3 (c) describes the contents of the memory when stored in the form of a "non-dot matrix pattern" font in hexadecimal notation. In the case of the present embodiment, the "compression" using the run-length method is used. Font ". Specifically, it consists of the following rules.

1. Each code unit is 4 bits. 2. Each horizontal direction (scan direction) has a delimiter code E (hexadecimal) (for example, in FIG. 3C). 3. The code E has the meaning that all the lower bits in one scan are “0” (OFF). 4. A scan line having exactly the same contents as the immediately preceding scan line is represented by a code “F” (for example, in FIG. 3C). 5. Each code unit (4 bits) in the scan is OFF
(White) and ON (black) in this order, and these are repeated (for example, in FIG. 3C, 6 is OFF and 13 is ON). 6. However, if the length is 13 or more, code D (16
Hex) and the sum of the following one code unit (4 bits) (for example, 8 in 19 in FIG. 3C). That is, only at this time, the length is represented by 8 bits.

For example, the content of the 14th scan “8464”
E " _nx is from left to right:" OFF is 8 bits, ON is 4 bits
t, OFF is 6 bits, ON is 4 bits, below OFF ”
Expresses image formation.

The contents of the 24th scan "44D14
E " _hx is also from left to right:" OFF is 4 bits, ON is 4 bits
it, OFF is 14 bits (13 + 1), ON is 4 bi
t, hereinafter OFF "expresses image formation.

By using the above rules, FIG.
It can be seen that the character pattern represented by (b) requires only 39 bytes of memory. In this embodiment,
Both the built-in character pattern generator 204 and the removable character pattern generator 205 are "non-dot matrix fonts" using this technique.

FIG. 4 is an external view of a detachable character pattern generator. Reference numeral 402 denotes the socket 206 or 207.
And is directly connected to the bus of the CPU 208 when mounted.

FIG. 5 is an overall flowchart showing the control of the CPU 208.

Thereafter, according to the flow chart of FIG. 5, the character code data stored in the input buffer memory 202 is converted into character pattern data from when the printer unit and the CPU board 101 of the present embodiment are turned on, and the frame buffer is converted. The operation from the transfer of the character pattern to the memory 209 to the printing by the page printer 211 will be described.

When power is supplied to the CPU board 101, the CPU 208 completes a predetermined initialization process (not shown), and immediately in S1, the detachable character pattern generator 205 is turned on by the left socket 206 (generally well). It is determined whether or not the character font is attached to the detachable character pattern generator 205 attached to the left socket. Perform pattern expansion in the font cache. That is, the "non-dot matrix font" as in the example shown in FIG. 3C is converted according to the above-described rule in the form of the example in FIG.
To be stored. If the detachable character pattern generator is not attached to the left socket 206, the process proceeds to S2,
Similarly, the character font stored in the built-in character pattern generator 204 is stored in the font cache memory 207. Although this process requires a relatively long time, it is performed at the time required for warming up the printer engine unit when the power is turned on, so that there is no hindrance to the user. The font cache memory is provided by the built-in character pattern generator 204 or the detachable character pattern generator 20.
Even after storing any one of the character patterns of any one of the font cache memories 5, about 20% of the font cache memory has room to be left unused.

Then, the process proceeds to a step S4, wherein the print data sent from the host computer 201 is received from the input buffer memory 203 via the input interface unit. Here, after receiving information for printing one character, that is, information such as a character code, designation of a printing position, and a type of font to be printed, the process proceeds to S5. In step S5, the character code is checked to determine whether the code is a page break (form feed) code. If it is not a page break code, it is a character code to be printed, so that step S
Then, the process proceeds to step S6 to check whether the character pattern to be printed is already stored in the font cache memory 207. If it is already stored, the process proceeds to S8, where the corresponding character pattern is transferred from the font cache memory 207 to the frame buffer memory 209 while controlling where the image is formed in the frame buffer memory.

If it is determined in step S6 that the character pattern is not stored in the frame buffer, the necessary character pattern is used by using the cache memory space left in the font caching in step S3 and step S2. To the font cache. If this empty space has already been filled, the character pattern that has been cached the most in the FIFO method is sequentially used.
We are responding by deleting them. When the process proceeds to step S8 after step S7, the above-described step S8 is also performed.
Are the same. After the character pattern for one character has been developed in the frame buffer memory 209 in this manner, the flow returns to step S4, and the above-described processing is repeated. On the other hand, if it is determined in step S5 that the code is a page break code, the process proceeds to step S9 and the output interface unit 210
, A video signal for one page is sent to the page printer printing unit, and the printing of one sheet is completed by the above-described electrophotographic process. Further, the process returns to step S4 to obtain the data of the next page, and repeats the above processing to create pages one after another.

[Other Embodiments] In this embodiment, a laser beam printer is used as an output device. However, the present invention is applicable not only to such a printer but also to an image output device such as a CRT.

In the embodiment, a font using the run-length technique is used as the "non-dot matrix type" font. However, other outline fonts that store so-called circle coordinates and fonts that store character strokes are also used. Also, it can be used in a wide range of "non-dot matrix fonts" such as fonts created by combining kanji radicals. Furthermore, although the font cache is provided on the RAM, it is easy to replace it with another storage medium (such as a hard disk).

Further, in this embodiment, both the built-in character generator and the detachable character generator are "non-dot matrix type".
Although fonts are used, they may have different techniques.

Although the detachable character pattern generator has two slots, it is easy to use three or more slots.

FIG. 6 shows an example similar to that of FIG. 2, but using one socket. In FIG. 6, only the socket 206 is provided. The description of the other parts is omitted. And
A control flowchart in this case is shown in FIG. 7 (similar to FIG. 5).

In this example, the socket 206 shown in FIG.
It is determined whether or not a font cartridge (removable character pattern generator) is mounted on the printer, and if so, the process proceeds to S3, where the pattern is developed from the font cartridge to the font cache. The other steps are shown in FIG.
The description is omitted because it is the same as.

As described above, according to the present invention, attention is paid to the fact that the character font of the font cartridge is generally used more frequently than the character font built in the apparatus, and the font cartridge is mounted. If that font is expanded to the font cache, and if not installed, the fonts built into the device body are expanded to the font cache, effectively using the font cache memory and improving the font cache hit rate. There is. This improves the output throughput of the entire output device.

[0037]

As described in detail above, according to the present invention, when starting up the apparatus, character pattern information constituted by a storage method other than the dot matrix can be converted into the dot matrix format. It has become possible to provide an output control method capable of deleting the character pattern according to the state.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an internal configuration of a laser printer to which the present invention can be applied;

FIG. 2 is a block diagram illustrating a configuration example of a printer control unit 101.

FIG. 3 is an explanatory diagram of a character pattern storage method in the embodiment of the present invention.

FIG. 4 is an external view of a detachable character generator in the apparatus of the present embodiment.

FIG. 5 is a flowchart showing a control operation of a CPU in the apparatus according to the embodiment.

FIG. 6 is a block diagram illustrating a configuration example of a printer control unit 101.

FIG. 7 is a flowchart illustrating a control operation of a CPU in the apparatus of the present embodiment.

[Description of Signs] 208 CPU 207 Font Cache Memory 209 Frame Buffer Memory

Claims (1)

(57) [Claims] 1. A step of controlling start-up of an apparatus in response to power-on, and, together with the step, converting character pattern information formed by a storage method other than a dot matrix into a dot matrix format and storing the converted information in a memory. A storage control step, a write control step of writing a character pattern obtained by the storage control step into an output memory based on a character code, output position information, and font type information; and A deletion control step of deleting a character pattern in accordance with a state of a memory;