JPH05246075A - Bit map data-generator - Google Patents

Abstract

PURPOSE:To prevent deterioration in the print quality by securely storing dots which form outline section. CONSTITUTION:The data of a present address and the data right before and behind the address are read by utilizing a bit data means 11 that converts data from a outline data storage means 1 to bit map data, a left side data read means 21 that reads print data from the bit map data, a present data read means 22, a one-dot right side data read means 23 and a two-dots right side data read means 24. Each of the data from the read means 21 or read means 24 is reversed by data reverse means 25, 26 and a logical thereof and the other is calculated respectively by a logical product operating means 27, 28. The results are also processed with a data reverse means 30 and logical product operating means 31, 32 in a manner same as above mentioned and the operated results are outputted to a logical sum operating means 33, thus the print data is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bitmap data generator for generating bitmap data suitable for a serial printer using a wire dot recording head from an outline font, and more particularly to a half dot protection processing technique.

[0002]

2. Description of the Related Art An outline font, which stores data representing characters and figures with its outline, has an extremely small amount of data compared to bit map data, so that a printer of high quality printing is particularly required. Is often used in. Such an outline font needs to be converted into bitmap data once at the time of printing, and in particular, in the wire dot type recording head, dots adjacent in the row direction are printed every other dot in order to enable high speed operation. , It is necessary to perform half dot protection processing of thinning out the bits for each dot in the row direction.

[0003]

Since such processing is usually performed by a logic circuit for mechanically thinning out dots one by one, as shown in FIG. When even-numbered dots are continuous in the row direction, even the dots in the contour portion are thinned out, which causes a problem that the contour of the character or pattern becomes unclear. The present invention has been made in view of such a problem, and an object of the present invention is to reliably save dots forming an outline portion to prevent deterioration of print quality regardless of half dot protection processing. It is to provide a novel bit map data generator capable of performing the above.

[0004]

In order to solve such a problem, in the present invention, a means for converting data from the contour data storage means into bitmap data, and one dot at the present address from the bitmap data. First, second, third, and fourth read out the print data converted before or just before, the data of the current address, the data of one dot ahead of the current address, and the data of two dots ahead of the current address, respectively.
Reading means, a first inverting means for outputting inverted data from the first reading means, a second inverting means for outputting inverted data of the data from the fourth reading means, a first inverting means and a second reading means. A first logical product calculating means for calculating a logical product of data from and, a second logical product calculating means for calculating a logical product of data from the third reading means and the second data inverting means, and a third
Third data inverting means for outputting inverted data of data from the reading means, fourth data inverting means for outputting inverted data of data from the second AND operation means, first AND operation means and fourth inversion means A third logical product calculating means for calculating a logical product of data from the second read means and a fourth logical product calculating means for calculating a logical product of the data from the third data inverting means; 4 logical product computing means for computing the logical sum of data from the logical product computing means.

[0005]

With the first to fourth reading means, by grasping the current address and the 4-bit data which is 1 bit before and 1 bit and 2 bits ahead of the present address, the bits constituting the contour portion are grasped. By converting two "1" data existing continuously before the "1" data on the leading edge side in the printing direction where two "1" data are consecutive, into two "0" data, Dot protection processing is performed to prevent at least the loss of dot data forming the left and right contours.

[0006]

The details of the present invention will now be described with reference to the illustrated embodiments. FIG. 2 shows an embodiment of the present invention. In the figure, reference numeral 1 is a contour data storage means for storing contour data in which characters and patterns are represented by their contour lines in association with character codes. The contour data includes the number of pieces of data, reference points of a plurality of lines expressing a pattern, that is, X-coordinate values and Y-coordinate values representing a start point and its end point, and a type of line connecting these start point and end point, For example, the line type data specifying a straight line, a parabola, and the like are configured as a set. Reference numeral 3 is a microcomputer constituting a bitmap data generator, and is programmed to output bitmap data matching the character code of the input buffer 2 to the print buffer 4.

FIG. 1 shows the microcomputer 3 described above.
2 is a block diagram showing functions to be performed by the reference numeral 1 in FIG.
Reference numeral 0 is a contour data reading means for accessing the contour data storage device 1 based on the character code of the input buffer 2 and outputting the contour data. Reference numeral 11 denotes a bit data conversion means, which in this embodiment represents a contour line by bits and sequentially performs a logical operation in the main scanning direction to generate data "1" in the area surrounded by the contour line. Is configured to let.

Numeral 20 is a half dot protection processing means which is a feature of the present invention. Based on the bit data generated by the bit converting means 11, when the first column is targeted, it is one bit to the left of the current address. Bit data of
When the second and subsequent columns are targeted, the left side data reading means 2 for reading out the print data converted in the immediately preceding step.
1. Current data reading means 2 for reading the data of the current address
2. 1 dot right side data reading means 23 for reading out 1 bit right side data of the current address, 2 dot right side reading means 24 for reading out 2 bit right side data of the current address, left side data reading means 21 and 2 dot right side data reading means. 24
Data inverting means 25 and 26 for inverting the data from
A logical product calculating means 27 for calculating a logical product of the data inverting means 25 and the data from the current data reading means 22, and a logic for calculating a logical product of the data from the 1-dot right data reading means 23 and the data inverting means 26. Product calculation means 28,
A data inverting means 29 for inverting the data from the 1-dot right side data reading means 23, a data inverting means 30 for inverting the data of the AND operation means 28, and a data inverting means 30.
And a logical product calculating means 31 for calculating a logical product of data from the logical product calculating means 27, a logical product calculating means 32 for calculating a logical product of data of the current data reading means 22 and the data inverting means 29, and a logical product A logical sum calculating means 33 for calculating a data logical sum of the calculating means 31 and 32 and outputting print data.
Are programmed to realize the following, and the truth values shown in Table 1 are output.

[0009]

[Table 1]

Although the operation result of the number 3 should originally be a circle, it is a circle, but since it is processed in order from the left, it becomes a circle when the number is 10. Therefore, in reality, the calculation result shown in No. 3 does not occur, and it does not cause an obstacle.

Next, the operation of the apparatus configured as described above will be described with reference to FIG.
It will be described based on the flowchart shown in FIG. When the print command is output, the contour data reading means 10 reads the character code stored in the input buffer 2 and the magnification data attached to this data, and the contour data matching the character code is read from the contour data storage device 1. read out. In this way, when the outline font corresponding to the character code stored in the input buffer 2 is converted into bitmap data, the data in the column direction at the address one dot to the left of the current address is read (step a). Temporarily store the inverted data of this data (step
B). A logical product of the data of the current address and the temporarily stored inverted data is calculated, and this is temporarily stored as the result 1 (step C).

Next, the data in the column direction at the address 2 dots to the right of the current address is read (step D), and the inverted data is temporarily stored (step E). Next, the data in the column direction of the address one dot to the right of the current address is read (step F), the logical product of this data and the inverted data obtained in step (e) is calculated, and this is temporarily stored as the result 2 ( Step).

The logical product of the inverted data of the temporarily stored result 2 data and the result 1 obtained in step (c) is calculated, and this is temporarily stored as the result 3 (step r).

Next, the data in the column direction of the address to the right of the current address by one dot is read (step), and the inverted data thereof is obtained (step n), and the logic of this inverted data and the data in the column direction of the current address. The product is calculated and temporarily stored as the result 4 (steple).

A logical sum of the result 3 obtained in step (i) and the result 4 obtained in step (l) is calculated and output as print data of the current address (step o). When the bit data for printing of the current address is output, the read address is shifted by one dot in the printing direction, to the right in this embodiment (step W), and the process from step (A) is repeated again to repeat the bit conversion means 11 Half-dot protection processing is executed for the bitmap data of. Needless to say, in the conversion of the data in the second and subsequent columns, it is clear that the data one bit to the left of the data to be processed is the print data converted immediately before.

FIGS. 5 to 8 show the above-mentioned arithmetic processing steps. The outline font to be printed is the bit data converting means 11 and the 4 bit × 8 bit bitmap data shown in FIG. It is described by taking the case of being converted to. Roman numerals I to VIII shown in FIGS. 3 and 5 to 8 show the transition of the current address.

Since all the bit data forming the I column in FIG. 3A is "0", data of "0" for all 4 bits is output by the operation process shown in I of FIG. 5 ( Fig. 3B I). Next, when the current address is shifted to the right by 1 bit and the II column in FIG. 3A is to be processed, the print data generated in the process of I in FIG. 5 is fetched and I in FIG.
Through the operation process as shown in I, data of "1" is output in all 4 bits and converted into data in which the left contour is preserved (II in FIG. 3B).

When the current address is further shifted to the right by 1 bit and the column III becomes the object of processing, the print data generated by II in FIG. 6 is taken in and all 4 bits are processed by the operation process as shown in III in FIG. Data converted into data of "0" and subjected to half dot protection processing is generated (III in FIG. 3B).

When the object to be processed shifts to the IV column, the print data, all of which have been converted to "0" by the immediately preceding calculation, is fetched as shown in IV of FIG. Data in which 2 bits are "0" and the other bits are "1" is output. As a result, the bit of the first line (the uppermost end in the figure) forming the contour is output as "1" as the original data, and the contour portion is held. Also, the dots adjacent to the dots in the contour on the second row from the top in the figure are converted to "0" following column III.

When the object to be processed shifts to the V column, only the second row is "0" due to the immediately preceding calculation as shown in V of FIG.
The print data converted to is captured, and the bit on the second line, which is the contour portion, is data "1" by the same calculation process as above.
, And the bit one bit before the bit which becomes the contour portion in the next VI column (left side in this embodiment) is converted to data "0".

Hereinafter, VI in FIG. 7 and VII and VII in FIG.
When there is an odd number of "1" data continuously existing from one end (left side in this embodiment) through the process indicated by I, every other column is converted into "0" data and thinned out bit by bit. In the case of an even number, the two bits before the other end (right side in this embodiment) are set to "0" and the bit at the end is converted into "1" data, and the bitmap pattern is output.

As a result, the half dot protection process can be performed without erasing the dots in the contour portion, which is the portion where the even number of dots are continuous. That is, since the edge is composed of 4 dots in consideration of the data 2 dots ahead of the current address and the data 1 dot before, the contour part is constructed even when the half dot protection processing is performed. It is possible to prevent thinning of existing dots.

In this embodiment, the case of printing from the left side to the right side has been described as an example, but in the case of printing from the right side to the left side, sampling of bitmap data for arithmetic processing is performed. It is clear that the same effect can be obtained by carrying out from the right side.

[0024]

As described above, according to the present invention,
The first to fourth reading means grasps the current address and the data for four columns in total, which is 1 bit before and 1 bit and 2 bits ahead of the present address. Among the bits forming the contour portion, "1" data is obtained. Half-dot protection processing is performed by converting two "1" data on the front side of the "1" data on the leading side in the printing direction that are continuous in even numbers into "0" data. It is possible to perform the half dot protection processing without erasing the dots forming the above, and it is possible to prevent the print quality from deteriorating.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention with the functions to be performed by a microcomputer.

FIG. 2 is a block diagram showing an embodiment of the present invention.

3A and 3B are diagrams showing bit map data before conversion and bit map data after conversion by the same apparatus, respectively.

FIG. 4 is a flowchart showing the operation of the above apparatus.

FIG. 5 is a diagram showing calculation steps I and II in the same apparatus.

FIG. 6 is a diagram showing calculation steps III and IV in the same apparatus.

FIG. 7 is a diagram showing calculation steps V and VI in the same apparatus.

FIG. 8 is a diagram showing calculation steps VII and VIII in the same apparatus.

9A and 9B show bit map data before being subjected to half dot protection processing and bit map data that has been subjected to half dot protection processing by a conventional processing method. FIG.

[Explanation of symbols]

 20 Half-dot protection processing means

Front page continuation (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location G06F 3/12 G G09G 5/24 9061-5G 8804-2C B41J 3/12 M

Claims (1)

[Claims] 1. A means for converting data from the contour data storage means into bitmap data, and print data, current address data, and current address data converted from the bitmap data to one dot before or immediately before the current address. First, second, third, and fourth reading means for reading data one dot ahead and data for two dots ahead of the current address, respectively, and first inversion outputting inverted data from the first read means. Means, second inversion means for outputting inverted data of the data from the fourth reading means, first AND operation means for operating a logical product of the data from the first inversion means and the second reading means,
Second AND operation means for calculating a logical product of data from the third reading means and the second data inverting means, and third data inverting means for outputting inverted data of the data from the third reading means, second Fourth data inverting means for outputting inverted data of data from the logical product calculating means, first logical product calculating means and fourth
Third logical product calculating means for calculating a logical product of data from the inverting means, fourth logical product calculating means for calculating a logical product of the data from the second reading means and the third data inverting means, and third, And a bit-sum calculating means for calculating a logical sum of the data from the fourth logical product calculating means.