JPH0659742B2 - Font pattern generator - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a font pattern generator, and more particularly to a character font pattern generator in a printer.

2. Description of the Related Art A conventional font pattern generator is disclosed, for example, in Japanese Patent Laid-Open No. 56-16178. FIG. 6 is a block diagram showing the configuration of this conventional font pattern generator. Reference numeral 1 is an external storage device in which font patterns are stored, 2 is a font pattern buffer for temporarily storing the font patterns read from the external storage device 1,
Reference numeral 3 is a control unit that controls the external storage device 1 and the font pattern buffer 2, and 4 is a determination unit that determines whether or not a corresponding pattern exists in the font pattern buffer 2. In the conventional font pattern generating device configured as described above, when the judging section 4 receives a character code, it judges whether or not the font pattern corresponding to the character code exists in the font pattern buffer 2. If it exists in the font pattern buffer 2, the font pattern is read from the font pattern buffer 2. If it does not exist, the sector in which the corresponding font pattern is stored is read from the external storage device 1 to the font pattern buffer 2 and then to the outside.

Problems to be Solved by the Invention However, the above-mentioned configuration has the following drawbacks.

(1) There is a limit to the patterns that can be buffered in the font pattern buffer 2, and when the number of character types to be read increases, the number of accesses to the external storage device 1 increases.

(2) When the external storage device 1 is a floppy disk device or the like, the access time (for example, head seek time to the target sector) increases due to physical restrictions depending on the access method.

(3) For example, when multilingual font patterns are used at the same time, the physical storage positions of the font patterns may be extremely distant from each other, and the above point (2) becomes more problematic.

Means for Solving the Problems The present invention is a font pattern generation device including a code conversion circuit, a font group start address conversion circuit, an adder, a comparison unit, a sorting unit, and a cutout processing unit.

With the above-described configuration, the present invention generates and sorts physical sector addresses by the code conversion circuit and the font group start address conversion circuit when a wide variety of font patterns are required. Next, by reading the font patterns of a plurality of sectors determined by the cut-out processing unit at one time, it is possible to reduce the number of disk accesses and the access time due to physical operation.

Embodiment FIG. 1 shows a block diagram of an embodiment of the present invention. The external storage device 1 stores font patterns grouped by size, font, and character type. The work buffer 8 is divided into a sector address part, a character number in the sector (a number indicating the number of pattern in the sector) part, and a storage order part. The storage order section contains 0, 1,
2 ... and the number are stored. The code conversion circuit 5 sends the character code string a and the character size selection signal b to the sector number 50.
1 and the sector character number 502. The font group start address conversion circuit 6 outputs the start sector address 601 of the font group corresponding to the combination by applying the character size selection signal b, the font style selection signal c, and the character type selection signal d. The adder 7 adds the font group start address 601 and the sector number 501, and outputs the sector address 701 in which the character font pattern corresponding to the character code is stored. The character code is the sector address 701 and the sector character number 5 in order.
It is converted to 02 and stored in the work buffer 8. The defective sector table 10 stores the defective sector address of the external storage device 1 and its alternative sector address in pairs. The comparison unit 11 uses the data 80 of the work buffer 8.
The sector address of 1 is compared with the defective sector address of the defective sector table 12 one by one, and if they match each other, they are replaced with a pair of alternative sector addresses. The source unit 12 sorts the data in the work buffer 8 using the sector address as a key, and stores it again in the work buffer 8. The cut-out processing unit 14 searches the work buffer 8, determines the read start sector address and the number of sectors within the determined number of read sectors, and sends them to the external storage device control unit 13. The external storage device 1 reads into the font pattern buffer 16 font pattern data for a specified number of sectors from the sector address specified by the external storage device control unit 13. The transfer control unit 15 uses the work buffer 1
Of the data of No. 3, only the necessary font pattern of the font pattern buffer 16 is transferred to the designated memory area based on the information of the sector number part and the storage order part.

The operation of the font pattern generating device of this embodiment having the above-described configuration will be described below. The character code a and the character size selection signal b are converted by the code conversion circuit 5 into a sector number 501 and a sector character number 502. The in-sector character number 502 is stored in the in-sector number part of the work buffer 8. The font group start address selection circuit 6 converts the character size selection signal b, the character style selection signal c, and the character type selection signal d into the starting sector address of the font pattern grouped for each size, character style, and character type. The adder 7 adds the sector number 501 and the start sector address 601 to calculate the sector address including the font pattern, and stores it in the sector address portion of the working buffer 8. According to the above procedure, a plurality of character codes are converted into a sector number 501 and a sector character number 502 one by one and stored in the work buffer 8. FIG. 2a shows this state. In FIG. 2, a is a sector address part, b is a character number part within a sector, and c is a storage order part. As shown in FIG. 3, the defective sector table 10 stores defective sector addresses and alternative sector addresses in pairs. In FIG. 3, D is a defective sector part and E is a substitute sector part. The comparison unit 9 includes a sector address section of the working buffer 8 and a defective sector table 10.
The defective sector address areas of are compared element by element to check if they match. Taking the example in FIG. 3, the sector address 5713 is registered as a defective sector.
Since it coincides with the fourth element of, the replacement sector address 5722 is replaced. The results are shown in Figure 2b.
The sorting unit 11 sorts, for example, in ascending order using the sector address portion of the work buffer 8 as a key. The results are shown in Figure 2c. The cut-out processing section 12 refers to the sector address section of the work buffer 8, determines the sector address and the number of sectors to be read, and sends them to the external storage device control section 13.
Here, for example, it is assumed that the sector addresses 1609 to 21 sectors, that is, 1619 sectors are read. The external storage device controller 13 reads the corresponding sector from the external storage device 1 and stores it in the font pattern buffer 14. This result is shown in FIG. The transfer control unit 15 transfers the required font pattern to the designated memory area based on the information of the in-sector number section and the storage order section of the work buffer 8. In FIG. 2c, sector address 1
609, the font pattern with the character number 0 in the sector is transferred to the first storage position, and the font pattern with the sector address 1618 and the character number 2 in the sector is transferred to the fifth storage position. This result is shown in FIG. According to the above procedure, all font patterns are read from the external storage device 1,
Repeat until the transfer is complete.

As described above, according to the present invention, various character sizes,
Even when reading out various fonts and font patterns of various character types, the number of physical accesses and access time are reduced. Therefore, a desired font pattern can be obtained at high speed, and its practical effect is great.

[Brief description of drawings]

FIG. 1 is a block diagram of a font pattern generator according to an embodiment of the present invention, FIG. 2 is a diagram showing changes in a working buffer of the embodiment, and FIG. 3 is a diagram showing an example of contents of a bad sector table. , FIG. 4 is a diagram showing a state of data read into the font pattern buffer by one access,
FIG. 5 is a diagram showing a state where only necessary font pattern data is transferred to a designated memory area, and FIG. 6 is a block diagram of a conventional font pattern generator. 5 ... Code conversion unit, 6 ... Font group start address conversion circuit, 7 ... Adder, 8 ... Work buffer,
9 ... Comparison section, 10 ... Bad sector table, 11 ...
Sorting unit, 12 ... Cutout processing unit, 15 ... Transfer control unit.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location G09G 5/26 8121-5G

Claims (1)

[Claims] 1. An external storage device for storing a character font pattern, a code conversion circuit for outputting a corresponding sector number and a character number within a sector by giving a character code and a character size selection signal, and a character type selection signal, Font selection signal,
A font group start address conversion circuit that outputs a start sector address in which a font pattern of a corresponding group is stored according to a character size selection signal; and an adder that calculates the sector address by adding the sector number and the start sector address. A work buffer for storing the sector address and the character number in the sector; a bad sector table for holding a bad sector address and an alternate sector address of the external storage device; and a sector address stored in the work buffer. A comparing unit that compares the defective sector addresses stored in the defective sector table and replaces the matched defective sector address with an alternative sector address; and a sorting unit that sorts using the sector address stored in the working buffer as a key. , The working buffer Read the start sector address, and the clipping processing unit for cutting the number of sectors, the clipping processing unit font pattern generating device having the external recording control unit that controls the external storage device in response to the signal from.