JPH03133672A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To shorten printing time by providing image data reading means for serially reading image data of a block in which a vacant flag is set, outputting it to an image forming unit, and setting the vacant flag of the read block to a vacant state. CONSTITUTION:A CPU 5 converts print data on a RAM 7 into pattern data if necessary, and sequentially develops them from the head of the block 21 of a random access port 9. If 511 words are developed, the vacant flag of the block is reset (nonvacant state, i.e., '0'). The CPU 5 develops image data of one page in the sequence of blocks 22 - 25, and resets the flags. Then, when an image printer 2 is started to print by the CPU 5, first timing signal is sent from an output interface 12, thereby transferring the data of 512 words of the block 21 to a serial port 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus that sequentially reads out image data developed in an image memory to form an image.

[Prior Art] Conventionally, in this type of apparatus, after printing all the image data developed in the image memory, the next image data is developed. For this reason, it took a considerable amount of time to print a plurality of images in succession.

[Problems to be Solved by the Invention] The present invention eliminates the drawbacks of the prior art described above, and its purpose is to provide an image forming apparatus that can shorten printing time.

[Means and operations for solving the problem] In order to achieve the above object, the image forming apparatus of the present invention sequentially reads out image data developed in an image memory to form an image. an image memory provided with a storage area for an empty flag; an image data expansion means for expanding image data into a block whose empty flag is empty and resetting the empty flag of the expanded block;
The outline of the present invention is to include an image data reading means that serially reads out the image data of the block whose vacant flag has been reset and outputs it to the image forming section, and makes the vacant flag of the read block vacant.

As a result, printing of the first developed image data progresses, and the next image data can be developed before the printing ends, increasing the total printing speed.

[Description of Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of a document processing apparatus including an image data output control section according to an embodiment. In the figure, 1 is a control unit that controls the output of image data for creating, editing, and printing document data, and 2 is an image printer that records images on recording materials according to image data sent from the control unit 1. (for example, a laser beam printer), and 3 is a CRT display section for displaying document data and the like.

In the control unit 1, 5 is a CPU, which performs main control of the document processing device. A ROM 6 stores a document processing program executed by the CPU 5. 7 is a RAM, which the CPU 5 uses as a work area. Also RAM
7 temporarily stores document data (character code data, image data read by a scanner (not shown), etc.) before being developed for printing or display. 8 is a floppy disk (
FD) and stores various document files as an external storage device. A keyboard (KBD) 4 provides various control commands in addition to creating and editing document data. 13
is a CRT interface (CRT I/F),
Controls the CRT display section 3. 15 is a video RAM (V
RAM) and stores image data for CRT display.

14 is a system bus of the CPU 5.

Furthermore, 16 is an image memory section, into which image data for printing is developed by the CPU 5, and the developed image data is serially read out in accordance with timing signals from the image printer.

The image memory section 16 of this embodiment is composed of a dual port memory, and has a random access port (RAP) that allows word data to be randomly accessed from the CPLI 5 side.
) 9 and a serial access port (SAP) 10 that can access serial data from the output interface 12 side to the image printer 2. Further, 11 is a timing signal generator, which counts the number of words read out from the serial access port 10 by counting the pixel clock signal, and outputs a control signal C to the serial access port 1o according to the counted output. .

FIG. 2 is a diagram illustrating the image data output operation in the image memory section 16 of the embodiment. In the figure, the memory of the random access port 9 has each predetermined size (for example, 512
Words) are divided into blocks 21 to 25, etc. Image data is stored in the first 511 words of each block, and the last 1 word (shaded area in the figure) stores the empty flag of the block.

With this configuration, the CPU 5 first converts the print data on the RAMT into corresponding pattern data if necessary,
These are expanded in order from the beginning of the block 21 of the random access port 9.

Eventually, when 511 words are expanded, the free flag for that block is reset (not free, for example 0).
). In the same manner, the CPU 5 executes the block 22.
The image data for one page is expanded in the order of 25 to 25, and the empty flags of each are reset.

Next, when printing by the image printer 2 is started by the CPU 5, a first timing signal is sent from the output interface 12.
Data for 12 words is transferred to the serial port 10. The image data transferred to the serial port 10 is based on the pixel clock signal CLK from the output interface 12.
is serially read out and sent to the image printer 2.

On the other hand, the timing signal generator 11 is reset by the first timing signal from the output interface 12 and counts subsequent pixel clock signals CLK. When the end of transfer for 511 words is counted, the output interface 12 temporarily stops data transfer to the image printer 2 by outputting a control signal C, and the serial access port 1O is set to write mode. The empty flag set information (for example, "1") is written in the final word (512th word). After writing this empty flag set information, the data in the serial port 10 is then transferred to the block 21. At this point, the last word of block 21 is rewritten from "0" to "1".

Next, the next first timing signal from the output interface 12 causes 512 words of data in the block 22 to be transferred to the serial port IO and processed in the same manner as described above.

On the other hand, after starting up the image printer 2, the CPU 5 reads out only the last word of each block in the random access port 9, thereby causing the image printer 2 to
It is determined whether data transfer to the block has been completed, and image data for printing the next page is developed for the block for which the transfer has been completed.

FIG. 3 is a flowchart of image memory transfer control according to the embodiment. In step S1, this process is started, and in step S2, one block of data is transferred from the random access port (RAP) 9 to the serial access port (SAP).
Transfer to 10.

In step S3, the image data read from the serial access port 10 is sequentially output to the image printer 2. In step S4, it is determined whether 511 words of image data in the serial access port 10 have been output, and if 511 words have not been output, the process returns to step S3 to repeat the output. Eventually, 511 words are completed,
Proceeding to step S5, serial access port 5 of 10
Write data “1” to the 12th word. Step S6
Then, the data on the serial access port 1o is transferred to the original block of the random access port 9. In step S7, it is determined whether the above processing has been completed up to the final block. If the final block has not been completed, the process moves to the next block in the random access boat 9 in step S8, and the process returns to step S2. If the last block has been completed, the process ends in step S9.

Note that in the above embodiment, a dual port memory was used as the image memory. This is because it is easy to transfer data between the random port and the serial port, and it is easy to write transfer end data (empty flag) to the serial port.

However, the present invention is not limited to the above embodiments.

For example, an image memory section that achieves the same effect can be constructed using a normal single-board memory.

In this case, the position where the empty flag is written is set every fixed length in the image memory. Then, the image data transferred to the image printer 2 is counted, and when the position of the empty flag is reached, the transfer operation is temporarily stopped, and information on the empty state is written there.

[Effect of the Invention 1] As described above (according to the present invention, the total printing time for multiple pages can be shortened).

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram of a document processing device including an image data output control section according to an embodiment. FIG. 2 is a diagram illustrating an image data output operation in an image memory section 16 according to an embodiment. FIG. 3 is an image diagram of an embodiment. 5 is a flowchart of memory transfer control. In the figure, 1...control unit, 2...image printer, 3...
・CRT, 5... CPU, 11... Timing signal generator, 16... Image memory unit.

Claims (1)

[Scope of Claims] An image forming apparatus that forms an image by sequentially reading image data developed in an image memory, comprising: an image memory having a storage area for an empty flag for each block; and an image memory in which the empty flag is empty. an image data expansion means for expanding image data into a block and resetting an empty flag of the expanded block; and serially reading the image data of the block whose empty flag has been reset and outputting it to an image forming section; An image forming apparatus characterized by comprising an image data reading means for emptying an empty flag of a block that has been created.