JPH0687236A - Printing control method in page printer - Google Patents

Abstract

PURPOSE:To prevent an occurrence of a shade caused by a high or low printing dot density to realize a constant-density printing in a page printer. CONSTITUTION:In a controller part 1, data of printing information is processed. In an engine part 2, an electrostatic latent image is formed on a printing drum 12, a toner is supplied onto the printing drum 12 by rotating a developing roller 16 to develop the electrostatic latent image, and the developed image is transferred to paper. In a printing control method for a page printer in which the paper is fed in synchronism with the forming of the electrostatic latent image for conducting printing, one page of paper is virtually divided into a plurality of layers in the controller part 1, and a printing dot density is calculated per layer and transmitted to the engine part 2. In the engine part 2, printing is carried out while the speed of the developing roller is controlled in accordance with a printing density by referring to the printing dot density per layer transmitted from the controller part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to data processing of print information by a controller section to form an electrostatic latent image on a print drum by an engine section, developing the electrostatic latent image and transferring it to a sheet. The present invention relates to a print control method for a page printer that prints by synchronizing the running of the paper with the formation of the electrostatic latent image.

[0002]

2. Description of the Related Art A page printer is a printer that prints all data for one page at a time when all the data for one page are collected. Here, a conventional technique for an electrophotographic page printer will be described. FIG. 7 is a block diagram showing a device configuration of a page printer for implementing this conventional example.

The apparatus is roughly divided into a controller section 1 for controlling print information and an engine section 2 for printing. An information output unit 3 such as a computer for transmitting information to the controller unit 1. First, in the controller unit 1, 4 is an interface connected to the information output unit 3, 5 is a reception buffer, and 6 is an editing unit. The editing unit 6 edits the print content for one page based on the information such as characters, print positions, form feeds indicating the end of pages transmitted from the reception buffer 5.

Reference numeral 7 is a page buffer, which specifies a character from a character code in which information sent from the editing section 6 has already been set, determines the type and size of the character, and also determines the character. This is a memory for storing information for which one page has been subjected to printing positioning and the like. Reference numeral 8 denotes a development unit that reads information from the page buffer 7, extracts actual print information from the character generator 9 as a character cell (a storage area for one character), and sends the information to the drawing memory 10 for actual Configures the state of one page to be printed on.

Reference numeral 11 denotes a print start control unit, which sends a signal to the print start control unit when the developing unit 8 has finished developing one page of data from the page buffer in the drawing memory 10. Detailed description of the editing unit 6 will be given with reference to the flowchart of FIG. 1 in the receive buffer in S801
The data is read byte by byte, the data is determined in S802, and if the data is control data, each control data is processed in S803 and the process returns to S801. If the determination data is print data, the type of print data is further determined in S804, and if it is graphics or K-line, the process is performed in S805 and S806 and the process returns to S801. If the judgment print data type is character, attribute information such as character size and movement amount is read in S807, and further in S808, this character is printed region based on the current cursor position information, the print area of the paper, the movement amount of the character, and the like. If not, the character is discarded in S809 and the process returns to S801. If it is within the print area, S81
0, S811 is stored in the page buffer, and the process returns to S801.

The controller unit 1 is constructed as described above. Next, the engine section 2 will be described. The engine unit 2 has a laser system, an LED system, a liquid crystal shutter system, etc., and in any case, printing is performed according to the principle as shown in FIG. In the figure, reference numeral 12 denotes a print drum. The surface of the print drum 12 is charged, and light is applied to the surface of the print drum 12 to expose it to form an electrostatic latent image, and the developing roller 16 is rotated. Then, the toner is supplied onto the print drum 12 to develop the electrostatic latent image with the toner, and the development is transferred to a sheet.
After fixing and printing is completed, the toner remaining on the print drum 12 after transfer is collected.

Each of the above-mentioned methods has a different method depending on the method of shining light upon exposure when forming the electrostatic latent image. Therefore, the rotation of the print drum 12 sends a signal to the print start control unit 11 when the edit unit 6 receives a form feed signal indicating the end of one page, and the print control is performed by the signal from the print start control unit 11. Part 13
Start the motor drive at the printing drum 1 at a constant speed.
Rotate 2 to run the paper at a constant speed.

On the other hand, the information from the drawing memory 10 is sent to the light emission control section 15 of the engine controller section 14 by a video signal, and the printing drum 12 is operated by any one of the above methods (the drawing shows a laser method). After the electrostatic latent image is formed on and developed, the developing roller conveys a certain amount of toner to attach the toner pattern to the paper, and the toner is fixed on the paper to print on the running paper. It can be performed.

Therefore, the transmission of the video signal and the traveling speed of the paper are controlled so as to be synchronized with each other, so that accurate printing can be performed at the correct position on the paper.

[0010]

However, according to the prior art having the above-mentioned structure, the rotation speed of the drum assumes the environment and conditions in which the device is used, and the controller processing capacity, engine processing capacity, cost, etc. The speed is set to be almost appropriate from the above condition, but this speed is a speed peculiar to the device and is not variable.

Further, the toner supplies a fixed amount that matches the print pattern with an average print duty. From the above, according to the conventional technique having the above-described configuration, if the print dot density exceeds the above average, the supplied toner becomes insufficient and the print density becomes thin.

Therefore, when there is a large amount of certain data from the information output section and the number of print dots in one page is large,
For example, when certain data from the information output unit prints one page in black with an image, the toner supply amount is not sufficient and print fading occurs, and a constant print density cannot be maintained. was there. Further, when there is a portion where the print dot density is higher than the average in one page, there is a problem in that the print density is reduced only in this high portion to cause shading, and it is not possible to maintain a constant print density.

In view of the above problems, the present invention provides a method of appropriately adjusting the toner supply amount in accordance with the print dot density which is variable for each print data, and causes the generation of shading due to the height of the print dot density. It is an object of the present invention to prevent and realize constant density printing in a page printer.

[0014]

To achieve the above object, according to the present invention, print information is processed by a controller unit, an electrostatic latent image is formed on a print drum by an engine unit, and a developing roller is rotated. Toner is supplied onto the print drum to develop the electrostatic latent image and transfer it to a sheet,
In a print control method of a page printer that prints by synchronizing the running of the paper with the formation of the electrostatic latent image, one page of the paper is virtually divided into a plurality of layers by a controller unit, and a print dot density is obtained for each layer. Is calculated and transmitted to the engine section, and the engine section controls the speed of the developing roller according to the print density by the print dot density for each layer from the controller section.

[0015]

With the above construction, the present invention virtually divides one page of paper into a plurality of layers in the controller section,
The print dot density is calculated for each layer, and the engine is notified when printing is started. The engine notifies the engine when printing is started for each layer in the engine, and the engine notifies each layer that is notified by the controller. It is possible to control the speed of the developing roller according to the print dot density in accordance with the print dot density, and perform printing while keeping the toner supply amount properly for each layer.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to the drawings. In addition,
In the following description, the same parts as those of the conventional example will be described with the same reference numerals. FIG. 1 is a block diagram showing an embodiment of the present invention. The structure in which the information from the information output unit 3 is sent to the controller unit 1 and the engine unit 2 prints based on the information is the same as the conventional example. is there. FIG. 2 is an explanatory diagram for explaining the layer management memory of the same embodiment.

The present embodiment is a laser printer having a resolution of 240 DPI (dot perinch) in both the main scanning direction and the sub-scanning direction, and the case of printing on A4 size cut-sheet paper will be described. It should be noted that the traveling direction of the paper is the Y direction, and the direction perpendicular thereto is the X direction. As shown in FIG. 2, 64 dots (1 dot is 1
/ 240 inch) and the layer management memory 17 of each layer is connected to the print start control unit 11 of the controller unit 1 as shown in FIG.

FIG. 3 is a flow chart showing the processing procedure at the time of printing start of the embodiment. As shown in FIG.
In this embodiment, a light emission control unit 15 is instructed to emit light by a video signal from the drawing memory 10, and the print activation control unit 1 is activated before the print activation control unit 11 starts motor driving.
1, the data written in the drawing memory 10 is read, the print dot density of each layer is calculated, and the layer management memory 17
Stored in (S301) and transmitted to the engine section (S30
2).

FIG. 4 is a flow chart showing the calculation procedure of the print dot density of each layer in this embodiment of S301. The print dot density of each layer is calculated and stored in the layer management memory 17 with reference to FIG. The flow up to is explained. First, the leading layer number is set in S401, the total number of dots C in the layer peculiar to the paper is determined in S402, and S403 and S4.
In 04, the initial value of the position of the layer N in the Y direction is set to y, and the total print dot number A of the layer N is updated. S407, S408
Update the y-position at and if it is not the end of layer N, S4
Returning to 05, if the end of the layer N, S409, S410
Print dot density Vn from constant C and total number A of dots in layer N
(Vn = A / C × 100) is calculated and stored in the layer management memory 17. Further, it is determined in S411 whether the layer N is the last layer, and if it is not the last layer, the layer N is incremented by 1 in S413 and S4 is executed.
Return to 03. If it is the last layer, the data in the layer management memory 17 is transmitted to the engine unit in S412. Subsequent processing is the same as that of the conventional technique, and will be omitted.

FIG. 5 is a flow chart showing the print control processing procedure of this embodiment. The print control processing of this embodiment will be described below. The engine unit 2 receives the content of the layer management memory 17 from the controller unit 1 in S501 and stores it in the memory, further receives a print start instruction from the controller unit 1 in S502, and starts the paper running in S503. In S504, the sheet is waited until the photosensitive timing, and when the photosensitive timing is reached, the 1-line print drum 12 is exposed in S505. If it is the end of the sheet in S506, the sheet is discharged to the discharge stacker in S510. Run and finish. If it is not the end, it is determined in S507 whether the development line is a layer switching portion. If it is not a switching portion, the process returns to S504, and if it is a switching portion, the print density data Vn from the layer management memory 17 is obtained in S508 and S509. Then, the speed of the developing roller 16 is determined from Vn, the speed of the developing roller 16 is changed to the determined value, and the process returns to S504. The other parts are the same as in the prior art, and will not be described.

[0021]

As described above in detail, according to the present invention, the print information is processed by the controller unit to form an electrostatic latent image on the print drum by the engine unit, and the developing roller is rotated to print on the print drum. In the print control method of the page printer, which supplies toner to the toner to develop the electrostatic latent image and transfers the electrostatic latent image to the paper, and performs printing by synchronizing the traveling of the paper with the formation of the electrostatic latent image. In this case, one page of paper is virtually divided into multiple layers and the print dot density for each layer is calculated and sent to the engine section. The engine section determines the print density by the print dot density for each layer from the controller section. Since the speed of the developing roller is also controlled, printing can be performed while keeping the toner supply amount proper for each layer.

As a result, it becomes possible to appropriately adjust the toner supply amount in accordance with the print dot density which is variable for each print data, to prevent the generation of shading due to the height of the print dot density, and to maintain a constant level in the page printer. This has the effect of realizing density printing.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a layer management memory according to an embodiment of the present invention.

FIG. 3 is a flowchart showing a processing procedure when printing is started according to an embodiment of the present invention.

FIG. 4 is a flowchart of a calculation procedure of print dot density of each layer according to an embodiment of the present invention.

FIG. 5 is a flowchart showing a print control processing procedure according to an embodiment of the present invention.

FIG. 6 is a schematic diagram showing the principle of a printer unit of a conventional example.

FIG. 7 is a block diagram showing a conventional example.

FIG. 8 is a flowchart showing a processing procedure of an editing unit of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 controller section 2 engine section 11 print start control section 12 print drum 13 print control section 16 developing roller 17 layer management memory

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location G03G 15/00 303 H04N 1/29 Z 9186-5C

Claims (1)

[Claims] 1. A controller unit processes data of print information to form an electrostatic latent image on a print drum by an engine unit, and a developing roller is rotated to supply toner onto the print drum to form the electrostatic latent image. I will develop it and transfer it to paper,
In a print control method of a page printer that prints by synchronizing the running of the paper with the formation of the electrostatic latent image, one page of the paper is virtually divided into a plurality of layers by a controller unit, and a print dot density is obtained for each layer. Is calculated and transmitted to the engine unit, and in the engine unit, the speed of the developing roller is controlled in accordance with the print density by the print dot density for each layer from the controller unit.