JPS62143126A - Thermal image printer - Google Patents

Abstract

PURPOSE:To compactly transfer image data like four picture elements/byte to speed up the data transfer by converting the image data including at least >=2 picture elements in a byte into data appropriate for a thermal head. CONSTITUTION:The data format of image data sent from a CG & printer controller 11 is converted by a format converting part 18 in accordance with a data transfer mode command discriminated by a compiler. The image data divided by the format converting part 18 are successively transferred to an one-line preceding shift register 19, a two-line proceding shift register 20 and a three-line preceding shift register 21. The image data are converted into proper data by a conversion ROM 22 while referring data preceded by one line and then dividedly stored in four-dived line buffers 32 formed in respective input data. When the buffers 32 are filled with data, the stored data are converted into a binary signal by a pulse width converting part 24. The data are divided into add numbers and even numbers by an odd/even distributing part 25 and inputted to a thermal head 13.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal image printer that performs multi-stage modulation recording per dot using a thermal head.

Section 01 Conventional printers of this type transfer image data only in a 1 pixel/byte data format in which 1 pixel is included in 1 byte.

1-1 flag The present invention provides image data in the form of, for example, 4 pixels/I3yt.
．． The purpose is to speed up the transfer by compressing the data as shown in e.

Configuration To achieve this object, the present invention includes a data conversion unit that converts image data in a data format in which one byte includes at least two pixels into data suitable for a thermal head. Features.

Next, the embodiment will be described in detail based on the drawings.

The thermal image printer according to the present invention includes a system controller (10) including a CPU, a character generator (CG), and a printer controller (10) in FIG.
1), data converter (12), and thermal head (13)
, a power supply voltage controller (14), and a mechanism section (15) including a stepping motor and the like. The system controller (10) has an operation panel (16).
) The entire sequence is controlled according to the operations. The character generator and printer controller (11) receives image data or character data from a data source (17) and
The command from 7) is determined by the compiler, and if it is image data, it is sent as is to the data conversion unit (12), and if it is character data, it is converted to image data according to the character by the character generator, and then data conversion is performed. Transfer to section (12). Is the power supply voltage controller (14) the power supply voltage? Correct according to the environmental temperature.

The data converter (12) converts the image data sent from the character generator and printer controller (11) into data suitable for the thermal head (13).

FIG. 2 shows the specific configuration of this data converter (12). Image data sent from the character generator and printer controller 1-roller (11) is converted into a data format by a format converter (18) according to a data transfer mode command determined by the compiler. The data transfer mode command is expressed as, for example, ESC+M0m+CR. Here, ESC is an extension command, M is a command indicating that a format is specified, and m is a command specifying the type of format.

CR is a carriage return. FIG. 3 shows the relationship between format types and pixels. When m=1, it is binary data, 1 pixel per I Byte. When lm=2, it is 4-value data, 1 pixel per I Byt, e. When m=3, it is 4
Value data has 4 pixels per I Byte, and when m=4, binary data has 8 pixels per I Byte.
Basically, it is controlled by a Centronics-compliant parallel interface method. FIG. 4 shows a timing chart of a general Centronics-compliant parallel interface. In addition, Fig. 5 shows the format conversion procedure for 4 pixels/Byte, and Fig. 6 shows the format conversion procedure for 1 pixel/Byte. In both cases, each pixel data is be divided.

The image data divided by the format converter (18) in this way is transferred to the pre-line shift register (19),
It is sequentially transferred to the 2-line previous shift register (20) and the 3-line previous shift register (21), and is converted into proper data by the conversion ROM (22) by referring to the data of 1 line before, and then each input data is When the buffer becomes full, it is converted into a binary signal by a pulse converter (24) with a threshold according to the weight of the dot data, and then the odd The -even distribution unit (25) divides the data into odd and even numbers and inputs them to the thermal head (13), where the odd and even numbers are transferred separately.

Layer---lol According to the present invention, the data from the video signal is 1 pixel/B
In the case of image data transferred in yte format and stored on a personal computer, etc., 4 pixels/B
It can be packed and transferred like yte.

Therefore, high-speed data transfer is possible in common Centronics-compliant interfaces. Furthermore, since the data format can be easily changed, it is compatible with a wide range of data sources.

[Brief Description of the Drawings] Fig. 1 is a block diagram showing an overview of the thermal image printer according to the present invention, Fig. 2 is a block diagram showing the specific configuration of its data conversion section, and Fig. 3 shows the types of data formats. An explanatory diagram showing the relationship between pixels, Figure 4 is a timing chart of a Centronics-compliant parallel interface,
FIG. 5 is an explanatory diagram showing the format conversion procedure in the case of 4 pixels/Byte, e, and FIG. 6 is an explanatory diagram showing the format conversion procedure in the case of 1 pixel/Byte.

Claims (1)

[Claims] 1. In a thermal image printer that performs multi-stage modulation recording per dot using a thermal head, image data in a data format containing at least two or more pixels in one byte is adapted to the thermal head. A thermal image printer characterized by comprising a data conversion unit that converts data into data. 2. The thermal image printer according to claim 1, wherein the data converter includes a format converter that divides image data in the data format into pixel data one by one. 3. The thermal image printer according to claim 1 or 2, wherein the data format is determined based on a command from a data source.