JPH04208473A - Character-code/image-data conveter and thermal recorder equipped therewith - Google Patents

Abstract

PURPOSE:To make a capacity of a memory small, a processing speedy, and enlarge or contract a character with other multiplying factor than integer multiples or reciprocal multiples of integer by converting a character code into an image data of an ordinary character size at character font table memory means and enlarging or contracting a dot pattern of the image data at dot pattern conversion table memory means. CONSTITUTION:In a character-code/image-data converter 1, a character font table of ordinary character size is provided in a character font table memory means 2. The character font table memory means 2 converts a character code into an image data and a dot pattern conversion table memory means 3 enlarges or contracts a dot pattern of this image data. When a length is to be multiplied by M/m and a width is to be multiplied by N/n at the dot pattern conversion table memory means 3, a rectangular image data having a length of m bit and a width of n bit is converted into a rectangular image data having a length of M bit and a width of N bit.

Description

[Detailed description of the invention]

[[E Required] Concerning a character code/image data conversion device that supplies image data of enlarged or reduced character size to an output device such as a printer or display device for a given character code, and a thermal recording device using the same. , the memory capacity for converting character codes into image data can be reduced, high-speed processing is possible, and characters can be enlarged or reduced at a magnification other than an integer multiple or a reciprocal of an integer. A character font table storage means for converting a character code into image data of a normal character size, and a dot pattern conversion table storage means for enlarging or reducing a dot pattern of the image data by one. Prepare and configure.
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[Industrial application field]

The present invention relates to a character code/image data conversion device that supplies image data of a character size enlarged or reduced to a given character code to an output device such as a printer or a display device, and a thermal recording device or thermal transfer device using the same. The present invention relates to thermal recording devices such as devices.

[Conventional technology]

Conventional character code/image data conversion devices of this type include the following. (1) Equipped with character font tables for various character sizes. (2) A device that is equipped with only a character font table of normal character size and uses a simple algorithm to obtain image data in which characters are scaled by an integer multiple or its reciprocal. (3) A vector character font table that enlarges adjacent points on a character by connecting them with a curved line.

[Problem to be solved by the invention]

However, since (1) and (3) above require a large capacity of memory, they cannot be used in small-sized output devices, and (3) requires a long time to calculate, so it cannot be used at high speeds. It cannot be used in printers, etc. The above (2) is
Characters cannot be enlarged or reduced at a magnification other than an integer or its reciprocal. In view of these problems, it is an object of the present invention to reduce the memory capacity for converting character codes into image data, enable high-speed processing, and furthermore, The present invention relates to a character code/image data conversion device capable of enlarging or reducing characters at a magnification other than double, and a thermal recording device using the same.

[Means for Solving the Problems and Their Effects] FIG. 1 shows the basic structure of a character code/image data converting device and a thermal recording device using the same according to the present invention. This character code/image data conversion device 1 has a character font table storage means 2 and a dot pattern conversion table storage means 3. The character font table storage means 2 converts the character code into image data of normal character size. The dot pattern conversion table storage means 3 enlarges or reduces the dot pattern of the image data. The character code/image data conversion device configured as described above includes a character font table of normal character size in the character font table storage means 2, and the character font table storage means 2 converts the character code into image data. , the dot pattern of this image data (
Since the font size (typeface does not matter) is enlarged or reduced, there is no need to provide character font tables for various character sizes, and the capacity of memory for converting character codes into image data can be reduced. Furthermore, since there is no need to perform scaling calculations as in the case of the vector font table method, character codes can be quickly converted into image data of enlarged or reduced characters. Furthermore, characters can be enlarged or reduced at a magnification other than an integer multiple or a reciprocal integer multiple. In the above character code/image data conversion device, the dot pattern conversion table storage means 3 is arranged vertically as M/
When multiplying the width by m and the width by N71, the length is m bits and the width is n bits.
If the configuration is such that the rectangular image data of bits is converted into rectangular image data of M bits in length and N bits in width, the capacity of the dot pattern conversion table storage means 3 can be minimized. For example, if you want to enlarge a character of any even number of dots in any font by 3/2 times, you will need a dot pattern conversion table that converts only 16 2-bit x 2-bit patterns into 3-bit x 3-bit patterns. All you have to do is prepare. In the above character code/image data conversion device, the dot pattern conversion table storage means 3 is provided with a thin line dot pattern conversion table for enlarging or reducing the dot pattern of image data by making it thinner than usual, and a thin line enlargement/reduction mode is specified. In this case, if the thin line dot pattern conversion table is used, the black rate will be reduced, which will increase the speed of printing (in this specification, "printing" includes printing of images such as figures) with a thermal recording device. Contribute to Further, in the character code/image data conversion device, the dot pattern conversion table storage means 3 is provided with a thick line dot pattern conversion table for enlarging or reducing the dot pattern of the image data by making it thicker than normal, and a thick line enlargement/reduction mode is specified. If the thick line dot pattern conversion table is used in such a case, it will contribute to increasing the speed of simultaneous printing of a plurality of copies using a thermal recording device. In the thermal recording device according to the present invention, as shown in FIG. 1, in addition to the character code/image data conversion device 1,
It has a black ratio conversion table storage means 4, an energization control means 5, and a print head 6. In the print head 6, heating resistive elements for thermal recording are arranged. The character code/image data conversion device 1 supplies image data to the black ratio conversion table storage means 4 and the print head 6. The black rate conversion table storage means 4 stores the image data as
The image data is converted into the number of black bits existing in each of a plurality of ranges when the image data is divided. The energization control means 5 controls the energization of the heating resistor elements of the print head 6 based on the data read from the black rate conversion table storage means 6. Since the thermal recording device configured as described above converts the image data into a black rate using the black rate conversion table storage means 4, the black rate can be determined at high speed, and high-speed printing is possible.

【Example】

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a character code/image data conversion device and a thermal recording device using the same according to the present invention will be described below with reference to the drawings. FIG. 2 shows the main structure of a thermal recording device to which a character code/image data conversion device is applied. The extended character code or image data is supplied to the extended character code/image buffer memory 10 in printing order and temporarily stored therein. This extended character code is configured as shown in Figure 3, for example, and includes a modification code and a character code C.
It consists of The modification code further includes an expansion/contraction code 8 and a font code B. The expansion/contraction code A is composed of, for example, two pins) A1 and A2. And beep) AI
For example, °0° represents normal font size, °
When it is 1°, it represents the character size enlarged by 3/2 times. Furthermore, for example, when A2 is "0", it indicates thin line enlargement, and when it is "1", it indicates thick line enlargement. For example, the font code B has a 1-bit configuration, and when it is 0', it represents a Mincho font,
When it is l, it represents a Gothic typeface. For example, the character code C is 1
This is a byte ASCII code and is expressed as a number from 0 to 255. The extended character code/image buffer memory 10 shown in FIG. 2 also stores 1-bit data for identifying whether the data is an extended character code or image data. The contents of the extended character code/image buffer memory 10 are supplied to one set of input terminals of a demultiplexer 12A with two selection outputs and a multiplexer 12B with two selection inputs. A set of output terminals of the demultiplexer 12A is connected to an address input terminal of a character font table ROM 14, and a data output terminal of the character font table ROM 14 is connected to a set of input terminals of a multiplexer 12C having four selection inputs. The other set of output terminals of demultiplexer 12A is directly connected to one set of input terminals of multiplexer 12C. Further, the output terminal of the character font table ROM 14 is connected to the other set of input terminals of the multiplexer 12B. Multiplexer 1
The output terminal of 2B is connected via the expansion/contraction circuit 16 to a set of input terminals of the multiplexer 12c. The output terminal of the multiplexer 12C is the image buffer memory 1
8 data input terminals. The selection control of the demultiplexer 12A1 and the multiplexers 12B and 12C is performed by the selection control circuit 20 according to the contents of the extended character code/image buffer memory 10.
The data moves as shown in ~(4). (1) When the content of the extended character code/image buffer memory 10 is an extended character code and the enlargement factor is 1 (normal character size), the character code C is supplied to the character font table ROM 14 via the demultiplexer 12A. The image data is converted into image data, and this image data is held in the image buffer memory 18 via the multiplexer 12C. (2) If the contents of the extended character code/image buffer memory 10 are extended character codes and the enlargement magnification is not 1,
The character code C is supplied to the character font table ROMI4 via the demultiplexer 12A and converted into image data, and this image data is sent to the multiplexer 1.
The dot pattern is supplied to the enlarging/reducing circuit 16 via the dot 2B, and the dot pattern is enlarged/reduced according to the enlargement factor, and is held in the image buffer memory 18 via the multiplexer 12C. (3) When the contents of the extended character code/image buffer memory 10 are image data and the enlargement factor is 1, this image data is held in the image buffer memory 18 via the demultiplexer 12A1 and the multiplexer 12C. (4) If the contents of the extended character code/image buffer memory 10 are image data and the enlargement factor is not 1,
This image data is supplied to the enlarging/reducing circuit 16 via the multiplexer 12B, and the image data is enlarged/reduced according to the enlargement factor, and is held in the image buffer memory 18 via the multiplexer 12C. The address and contents of the character font table of a certain typeface stored in the character font table ROM 14 are as follows:
When the character code C is a 1-byte character, it is as shown in FIG. In other words, if one character is represented by (m+1) lines of image data, and one line is represented by one byte, then if C=1, then the first line (k=1~
m+1) image data is at address AO+256
It is stored in (k-1)+i. The starting address AO of the character font table 14A is determined by the value of the font code B. Character font table R shown in Figure 2
The OM 14 stores all character font tables of fonts corresponding to the value of font code B. From the above, the address of the character font table ROM 14 is the fifth
As shown in the figure, it is represented by a font code B, a line number D specified by a counter (not shown) that counts clocks, and a character code C. 21st! An example of the expansion/contraction circuit 16 shown in FIG. 1 is shown in FIGS. 6A and 6B. The magnification factor of this enlarging/reducing circuit 16 is only 3/2, and FIG. 6A shows the dot pattern conversion state in the thin line 3/2x mode, and FIG. 6B shows the dot pattern conversion state in the thick 113/2x mode. Indicates conversion status. In FIG. 6A, the original image buffer register 161
holds 2 bytes of image data supplied from multiplexer 12B. This 2-byte image data is a 2x2 rectangular image part 1 with 2 bits each in the vertical and horizontal directions.
The signals are divided into 6A to 16D, and each of them is supplied to a multiplexer 162 that selects four groups manually. Here, the dot pattern conversion table ROM 163 stores a conversion table for thin line enlargement and a conversion table for thick line enlargement, and when the content of the enlargement/reduction code A is "10°", the conversion table for thin line enlargement is selected. , when the content of the expansion/reduction code A is 11 degrees, the thick line expansion conversion table is selected.The dot pattern conversion table ROM 163 is addressed by a set of 4 bits selected by the multiplexer 162,
From the dot pattern conversion table ROM 163, image data enlarged to three pits in the vertical and horizontal directions is read out. This image data is held in one of the 3×3 rectangular image units 16R to 16U, each having 3 bits in the vertical and horizontal directions, constituting the enlarged image buffer register 165 through a demultiplexer 164 with four selected outputs. This enlarged image buffer register 165 is normally composed of 2 bytes x 3. Selection control of the multiplexer 162 and the demultiplexer 164 is performed by the count value of a quaternary counter 166 that counts the clock CLK. That is, the contents of the 2X2 rectangular image sections 16A to 16D are stored in the 3X3 rectangular image sections 16R to 16, respectively, in this order.
Converted to the contents of U. Figures 6A and 6B each show four patterns of ta.
An example of s enlargement conversion and an example of thick line enlargement conversion are shown.
corresponds to a sunspot. When enlarging a character with an arbitrary even number of dots in an arbitrary typeface by 3/2 times, it is sufficient to provide a dot pattern conversion table that converts only 16 2-bit x 2-bit patterns into 3-bit x 3-bit. . 6th A
Since pattern conversions other than the four patterns shown in the figures and FIG. 6B can be easily inferred from these four pattern conversions, their explanations will be omitted. By means of the enlargement/contraction circuit 16 configured in this manner, for example, characters of 16 dots vertically by 8 dots horizontally in various fonts can be converted into characters of 24 dots vertically by 12 dots horizontally. In FIG. 2, the image data held in the image buffer memory 18 is directly supplied to the print head 24, and is also supplied to the division/energization time determination circuit 22 to create energization control data. is supplied to FIG. 7 shows an example of the division/energization time determination circuit 22. The image buffer register 221 holds the image data supplied from the image buffer memory 18,
The black ratio table ROM 222 is addressed by this image data, and the black ratios BNI to BN5 are read out.
It is held in the black rate buffer register 223. Black rate BNI
~BN5 is the image buffer register 2 as shown in the figure.
When 21 is divided into 3 parts in 4-bit units, 4 bits from the most significant bit, 8 bits from the most significant bit, 4 bits from the least significant bit, 8 pits from the least significant bit, and a total of 12
This is the number of 1" bits included in each range of pits. Conventionally, these black ratios BNI to BN5 were calculated by calculation, but in this embodiment, the image buffer register 2
Since the black ratio table ROM 222 is addressed with the contents of 21 and the black ratios BNI to BN5 are read out, the black ratios BNI to BN5 are read out.
BN5 can be determined quickly. The contents of the black ratio buffer register 223 are supplied to the division/energization time determination processor 224, which divides the plurality of heat generating resistive elements arranged in the print head 24, as is well known, so as to reduce and uniformly consume power and prevent printing from blurring. In order to print at high speed, the number of divisions and the energization time of each divided area are determined and supplied as energization control data to the print head 24 shown in FIG. 2. Note that the present invention includes various other modifications. For example, the ROM may be any other storage means, the components 12A, 12B, 12C, and 20 shown in FIG.
Of course, 2 may be composed of memory and software.

【Effect of the invention】

As explained above, the character code/image data conversion device according to the present invention converts character codes into image data using a character font table storage means storing a character font table of normal character size, and has a relatively large storage capacity. Since the dot pattern of this image data is enlarged or reduced by a small dot pattern conversion table storage means,
There is no need to prepare character font tables for various character sizes, the amount of memory required to convert character codes into image data can be reduced, and there is no need to perform scaling calculations as in the case of the vector font table method. This is an excellent method that can quickly convert character codes into image data of enlarged or reduced characters, and can also enlarge or reduce characters at a magnification other than an integer or reciprocal of an integer. be effective. In the above character code/image data conversion device, the dot pattern conversion table storage means has a length of M/m.
When multiplying the width by N/n, rectangular image data of m bits in height and n bits in width is converted to M bits in height and N bits in width.
If the configuration is to convert to bit rectangular image data,
This has the effect that the capacity of the dot pattern conversion table storage means 3 can be minimized. In the above character code/image data conversion device, when the dot pattern conversion table storage means includes a thin line dot pattern conversion table for enlarging or reducing the dot pattern of image data by making it thinner than normal, and a thin line enlargement/reduction mode is specified. If the thin line dot pattern conversion table is used in this, it will contribute to speeding up printing in a thermal recording device. Further, in the character code/image data conversion device, the dot pattern conversion table storage means is provided with a thick line dot pattern conversion table for enlarging or reducing the dot pattern of the image data by making it thicker than usual, and a thick line enlargement/reduction mode is specified. In such a case, if the thick line dot pattern conversion table is used, it will contribute to increasing the speed of simultaneous printing of a plurality of copies with a thermal recording device. As shown in FIG. 1, the thermal recording device according to the present invention further includes, in addition to the character code/image data conversion device, a black rate conversion table storage means, an energization control means, and a print head, Since the image data is converted into black ratio by the black ratio conversion table storage means, the black ratio can be determined at high speed, and high-speed printing is possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the basic structure of a character code/image data conversion device and a thermal recording device using the same according to the present invention. 2 to 7 relate to an embodiment of a character code/image data converting device and a thermal recording device using the same according to the present invention, and FIG. 2 shows a thermal recording device to which the character code/image data converting device is applied. A block diagram showing the configuration of the main parts of the recording device, Figure 3 is a configuration diagram of the extended character code, Figure 4 is a configuration diagram of the character font table, Figure 5 is a configuration diagram of the character font table address, and Figure 6A is the configuration diagram of the thin line 372.
An enlarged/reduced circuit diagram showing the conversion state in the case of double mode. Figure 6B is an enlarged/reduced circuit diagram showing the conversion state in the case of 3/2 times mode with thick lines. 7th! ! 1 is a division/energization time determination circuit diagram. In the figure, 16A to 16D are 2x2 rectangular image parts 16R to 16U.
The 3×3 rectangular image portion 161 is the original image buffer register 165 is the enlarged image buffer register character code extended character code/image data modification code from the multiplexer 12B.

Claims (1)

[Claims] 1) Character font table storage means (2) for converting character codes into image data of normal character size; and dot pattern conversion table storage means (2) for enlarging or reducing the dot pattern of the image data. 3) A character code/image data conversion device (1) characterized by having the following. 2) The dot pattern conversion table storage means (3) converts rectangular image data of m bits in length and n bits in width to M bits in height when multiplying the height by M/m and the width by N/n. 2. The apparatus according to claim 1, wherein the image data is converted into rectangular image data of N bits in width. 3) The dot pattern conversion table storage means (3) has a thin line dot pattern conversion table that enlarges or reduces the dot pattern of the image data by making it thinner than normal, and when a thin line enlargement/reduction mode is specified. 3. The apparatus according to claim 1, wherein the thin line dot pattern conversion table is used. 4) The dot pattern conversion table storage means (3) has a thick line dot pattern conversion table that enlarges or reduces the dot pattern of the image data by making it thicker than usual, and when the thick line enlargement/reduction mode is specified. 3. The apparatus according to claim 1, wherein the thick line dot pattern conversion table is used. 5) A print head (6) in which heating resistive elements for thermal recording are arranged, and the image data is supplied to the print head.
The character code/image data converting device (1) according to any one of items 4 to 4, converting the image data into the number of black bits present in each of a plurality of ranges when the image data is divided. , a black ratio conversion table storage means (4), and an energization control means (5) for controlling energization of the heating resistor element of the print head based on the data read from the black ratio conversion table storage means. A thermal recording device characterized by: