JPH0252763A - Printer - Google Patents

Abstract

PURPOSE:To increase the quantity of initial development, and to enable normal printing in reprinting by allocating one part of a text buffer area to a video band buffer (VBB) and providing a control means automatically augmenting the capacity of the VBB when an overrun error is generated. CONSTITUTION:When an overrun error is detected by an overrun error detecting section 6a, a text data on a text buffer is relocated, and a VBB area variable means 6b is expanded to VBB size B' while text buffer size is scaled down to B. Since a VBB is spread automatically and reprinting is conducted, printing can be performed onto an aimed page without reducing the data on the page even in a printer having no image development area corresponding to one page.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a printing device used as an output device of a personal computer or the like.

BACKGROUND OF THE INVENTION In recent years, printing devices have been required to be faster and more functional. In particular, electrophotographic printing devices that use laser diodes, LED arrays, or the like as light sources are fast and have high printing quality, so the fields of use are expanding significantly. Naturally, a high-speed printing device such as the above-mentioned printing device is required to have high printing data processing ability. There are various types of these print data processing methods, but they can be broadly classified into two types of processing methods.

Hereinafter, conventional examples of two types of processing methods will be explained with reference to the drawings. FIG. 6 is a block diagram of a conventional printing device of page memory type. The printing device 11 includes a controller unit 111L that processes print data sent from the host computer 12 and a printing unit 11 that prints on paper.
It is divided into b.

The controller unit 11& includes a CPU 13 that controls data processing, a program ROM 1a that stores a program for operating the CPU 13, a font RoM 16 that stores font data corresponding to character codes, and an interface that receives print data from the host computer 12. Section 16. A page memory section 24 that stores one page of image data, and a parallel-serial converter 20 that reads out the image data stored in the page memory section 24, converts it into serial data, and outputs it to the printing section 11b.
bite from

The operation of the conventional page memory type printing apparatus configured as described above will be described with reference to the processing procedure diagram of FIG. ! In FIG. 7 , the printing device 11 receives a character code from the host computer 12 . character code 61
) 1 is K to represent the alphabet lowercase letter It a.
A character code is determined for each character in a one-to-one correspondence.

The CPU 13 interprets this character code and stores it in the font ROM.
The corresponding font data is read from 1s and written into the page memory section 24. In this way, the image to be printed in the page memory section 24! One page worth of data is created (M7 Figure 0). When the image creation for one page is completed, the controller section 111L activates the printing section 11b and starts outputting print data. The print data is converted from parallel data to serial data for each raster by the parallel-serial converter 20 and sent to the print unit 11b.
The print result shown in Fig. 4 @ is obtained.

As described above, the conventional printing apparatus of the page memory type has the advantage of being able to store the exact image data of one printed page, but has the disadvantage of requiring a very large amount of memory. For example, when printing on letter paper (8.6 inches x 11 inches) at a resolution of 300 dots/inch, a memory capacity of approximately 1 MB (1 megabyte) is required. In order to solve the above-mentioned drawbacks, there is a video band gap type (hereinafter referred to as VBB type) printing device which performs printing using an image development area of '/n pages.

A conventional example of the VBB system will be described below with reference to the drawings.

FIG. 8 is a block diagram of a conventional printing device of the VBB type. The printing section fif11 includes a controller section 11a' that processes print data sent from the host computer 12, and a printing section 11b that prints on paper.
It can be divided into The printing section 11b has the same configuration as the printing section of the page memory type printing device. Controller part 1
1a' is the CjPU13 that controls data processing.
, a program ROM 14 that stores a program for operating the CPU 13, a font ROM 15 that stores font data corresponding to character codes, an interface section 16 that receives print data from the host computer 12, and stores character codes in the form of text in one page. A text memory section 18 that stores image data for one page, a 788 section 19 that stores '/n pages of image data, and a parallel parallel memory section that continuously outputs the image data stored in the 788 section 19, converts it into serial data, and outputs it to the printing section 11b. It consists of a serial converter 2o.

The operation of the conventional printing apparatus of the VBB type constructed as described above will be explained with reference to the processing procedure diagram shown in FIG. In FIG. 7 , the printing device 11 receives a character code from the host computer 12 . This character code is CP
The U 13 interprets and creates a text by adding information such as the character code and the writing position of the character in the VBB part 1 section 9 in the text memory section 18. In this way, a text group corresponding to the character codes for one page is created in the text memory section 18 (FIG. 7@). After creating one page of text, the CjPU 13 writes the font to the VBB section 19 while interpreting the text from the beginning. 788 part 19 is'/
Since the memory capacity is only for n pages, the CPtT 13 can initially only interpret text for l/n pages. When the image for 1/n page is completed, the CP
U13 activates the printing unit 11b to start printing (
Figure 7 ■). At the same time, the print data from the 788 unit 19 is output to the parallel-to-serial converter 20 for each raster, converted into serial data, and output to the print unit 111). By outputting each raster, an empty area is generated in the VBB section 19. The GPU 3 writes the next raster image into the VBB section 19 every time an empty area occurs.

By alternately repeating the output from the VBB section 19 and the writing to the VBB section 19 in this way, it is possible to print one page ((2) in FIG. 7). For this reason, the VBB section 19 normally has a ring buffer structure, and has a capacity of "/n" of one page, but can be used infinitely in terms of virtual address space.

As described above, the conventional printing device using the VBB method can perform printing with 1/n of the VBB and a small amount of text memory compared to the printing device using the page memory method, so it has the advantage of being able to significantly reduce the memory capacity.

Problem to be Solved by the Invention However, in the VBB type printing device, when a predetermined amount of empty area occurs in the VBB section 19, the image development data of the next raster is transferred to the VBB section 19.
However, if the time required to perform image development becomes long, image development data for several rasters may be read out by the print unit while image development for one raster is performed. , the amount of image development data stored in the VBB section gradually decreases,
Eventually it will reach °0゛. In this state, the printing section becomes unable to read the image development data and becomes unable to print, resulting in a so-called overrun error.

Means for Solving the Problem Therefore, in the printing device of the present invention, when an overrun error occurs, a part of the text buffer 1 area on the RAM is allocated to the video band buffer for storing the image, and the VBB capacity is automatically adjusted. It is provided with a means for controlling the increase in the amount.

Effect If an overrun error occurs due to the above method,
Since the VBB area is expanded and the initial development amount is increased, normal printing is possible in reprinting.

Example Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of the main parts of a printing device according to an embodiment, in which 1 is a host computer, and 2 is an interface for importing text data, image data, and control data sent from the host computer. 3a is a program RO storing a program for controlling a series of printing processes; 3b is a phono ROM in which font data is stored in advance; 4
operates according to a program stored in the program ROM 32L of the microcomputer to create text data and image data for printing, which will be described later. 5 is a random access memory for storing text data sent from the host computer while classifying it into text groups starting from the same raster, and for storing each text created on the text buffer. Contains VBB for storing data as an actual print image.

6 is a VBB control unit, which includes an overrun error detection unit 61L that detects the occurrence of an overrun error, and VBB area variable means 6b that varies the VBB area size. Reference numeral 7 denotes a parallel-to-serial converter which supplies the image data sequentially increased from the VBl area to the printing unit as serial data. Reference numeral 8 denotes a printing unit that performs actual printing operations and visualizes a target image on the recording medium based on the data from the parallel-to-serial converter 7.

R in the printing device of this embodiment configured as described above.
The relationship between the text buffer in AM and VBH will be explained using FIGS. 2 and 3.

Figure 2 shows a text buffer (s-
1) and VBB(5-2)+7) This is a schematic diagram showing the relationship between VBB(5-2)+7), and shows how a part of the area which was a text buffer in the initial state is gradually allocated to VBH. In the initial state, text buffer size is 1 and VBB size is A.
', when an overrun error occurs and is detected by the overrun error detection section 6a, after rearranging the text data on the text buffer, the VBB area variable means eb changes the VBBy size to B. ', the monitor text buffer size is reduced to B.

Figure 3 shows the text buffer (s-1), ! :VBB(s
-2) is a schematic diagram for explaining the data stored in the computer and its flow, in which a group of page data sent from the host computer is stored on a text buffer 1 in a first raster group p-text, a second raster group p-text, group,·····
. . . As shown as the n-th raster group μm text, each group starting from the same raster is arranged in the memory as a maximum of 64 rasters of text in the vertical direction. When all the text data in the page is placed on the text buffer, the text data on the text buffer is stored while being converted into an image to be actually printed on the VBB.

3-2 shows how the image is developed on the VBB, with 'e' and 'a' of the nth raster group being developed following 'mu' and 'ItC' of the first raster group. It means that.

Furthermore, the expansion of the BVV area, which is the greatest feature of this embodiment, will be explained based on the flowchart of FIG. 4 and the detailed VBB diagram of FIG. 5. First, as shown in step (a) of Fig. 4, in the initial state, VBB is set to 128 rasters in RAM, and the contents of the text buffer begin to be developed on VBB in step (b) (Fig. 6). When the expansion progresses and the remaining rasters become 63 rasters (in this case, when the first 65 rasters have been expanded), step (d) is executed based on the condition judgment of step () and ).
Then the actual printing operation begins. Next, in step (e), it is determined whether or not a vacant area for 64 rasters has been generated. However, since there is no vacant area for 64 rasters at first, it is again determined whether a vacant area for 64 rasters has been generated. conduct. Video signal output progresses 1
When one raster's worth of data is output, a total of 64 rasters, one minute on the upper address side of VBB and one raster on the lower address side, become an empty area, and step (to)
will expand the text starting from the next raster (
(Development of the character "JIB" in Figure 6). In this way, the text buffer is created while constantly checking whether there is an empty area for 64 rasters between the raster that is the starting point of development and the raster that is being output as a video. The expansion from VBB to If the amount is less, the time it takes to develop the text into VBB is shorter than the time it takes to output the video signal for one raster, so the judgment process in step (E) is skipped by μm, and the number of p-pups is determined by the amount of text. However, as the number of texts on the same raster increases, the number of pop-ups decreases, and finally it becomes possible to expand text starting from the next raster at the same time as step (E) is determined. If this state continues, the distance between the raster being developed and the raster being outputted as video will decrease, and an overrun error will occur where the video output raster will eventually catch up with the text developed raster.

When this overrun error occurs, the VBB area variable means 6b gradually widens the area occupied by VBB on the RAM shown in FIG. 2, and narrows the area occupied by the test buffer.

After that, the page where the overrun occurred is reprinted. To explain in more detail, when the video signal output raster catches up with the text development raster and an overrun error is detected in step (g) in Figure 4, the process proceeds to step (su) and initializes the VBB amount. Increase the setting amount from 128 rasters by 1 minute to 68 rasters by 1
One minute is 96 rasters. When it is confirmed that the VBB corresponding to one minute of 196 rasters has been secured in step (N), the process returns to step (B) and the above-described operation is repeated again. In this embodiment, the initial setting amount of VBB is 12
Although the amount is increased by 64 rasters once an overrun error occurs, this is merely an example and can be determined by considering the RAM capacity of the device and the printing speed.

As described in detail, according to the present invention, when the amount of data on a page is extremely large, the VBB is automatically expanded and reprinted after an overrun error occurs, so that the amount of data for one page is automatically expanded and reprinted. Even with printing devices that do not have an image development area, it is now possible to print the desired page without reducing the data on the page.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the main parts of an embodiment of the printing device of the present invention, FIG. 2 is a schematic diagram showing the relationship between the text buffer 1 and VBB of the same embodiment, and FIG. An explanatory diagram to show the flow of data between VBBs, FIG. 4 is a flowchart showing the operation of the same embodiment, FIG. 6 is a diagram to explain VBB in detail, and FIG. 6 is a diagram of a conventional printing device. FIG. 7 is a block diagram of the processing procedure of the same apparatus, and FIG. 8 is a block diagram of another conventional printing apparatus. 1...Host computer, 2...Interface, 32L...Program ROM
, ab... Font ROM, 4... Microcomputer (cptr), s... Random access memory, 6... V B B control unit, ea. ...Overrun error detection section, 6b
. . . VBB area variable means, 7 . . . Parallel-serial converter, 8 . . . Printing section.

Claims (1)

[Claims] a memory comprising a first area for storing text data such as a character code and a second area for storing image development data corresponding to the data such as the character code; The text data is stored in the first area, and the image development data corresponding to the text data stored in the first area is stored in the second area.
a control means for storing data in the second area; a printing means for reading data from the second area and printing it;
overrun error detection means for detecting an overrun error that occurs when the printing means starts reading out the image development data of the raster before the storage of the image development data of the raster in the area is completed; A printing device comprising means for increasing the second area in the memory when an overrun error is detected by the overrun error detection means.