JP2926112B2 - Print control method in page printer - Google Patents

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 in a controller unit, forming an electrostatic latent image on a print drum by an engine unit, developing the electrostatic latent image with toner, and transferring the electrostatic latent image to paper. The present invention relates to a printing control method for a page printer that prints the paper in synchronization with the formation of the electrostatic latent image.

[0002]

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

The apparatus is broadly divided into a controller section 1 for controlling print information and an engine section 2 for printing. Reference numeral 3 denotes an information output unit such as a computer that transmits information to the controller unit 1. First, in the controller 1, reference numeral 4 denotes an interface connected to the information output unit 3, reference numeral 5 denotes a reception buffer, and reference numeral 6 denotes an editing unit. The editing unit 6 edits the print content of one page based on information transmitted from the reception buffer 5 such as characters, print position, and form feed indicating the end of the page.

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

[0005] Reference numeral 11 denotes a print start control unit, which sends a signal to the print start control unit when the data of one page from the page buffer is completed in the drawing memory 10 by the developing unit 8. The editing unit 6 will be described in detail with reference to the flowchart of FIG. In S801, data is set to 1 from the reception buffer.
The data is read out byte by byte, the data is determined in step S802, and if the data is control data, each control data is processed in step S803 and the process returns to step S801. If the determination data is print data, the type of print data is further determined in step S804. If the determination data is graphics or key line, the processing is performed in steps S805 and S806, and the process returns to step S801. If the determination print data type is a character, in S807, attribute information such as the size and movement amount of the character is read out. If not, the character is discarded in S809 and the process returns to S801. If it is in the print area, S81
0, stored in the page buffer 7 in S811, and S801
Return to

[0006] The controller section 1 is established as described above. Next, the engine unit 2 will be described. The engine unit 2 includes a laser system, an LED system, a liquid crystal shutter system, and the like. In any case, printing is performed according to the principle shown in FIG. In the figure, reference numeral 12 denotes a printing drum, which charges the surface of the printing drum 12 and irradiates it with light by any of the above-described methods to form an electrostatic latent image, and rotates the developing roller 16. Then, toner is supplied onto the print drum 12 to develop the electrostatic latent image with the toner, and the developed image is transferred to paper.
The printing is completed by fixing, while the toner remaining on the printing drum 12 after the transfer is collected.

[0007] Each of the above-mentioned methods is different depending on the difference in the method of applying light at the time of exposure when forming the above-mentioned electrostatic latent image. Therefore, the rotation of the printing drum 12 is controlled by sending 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. Part 13
To start the motor drive and print drum 1 at a constant speed.
2 to rotate the paper at a constant speed.

On the other hand, the information from the drawing memory 10 is sent to the light emission control unit 15 of the engine controller unit 14 in the form of a video signal, and the printing drum 12 is used as described above by one of the above methods (the drawing shows a laser method). An electrostatic latent image is formed on the electrostatic latent image, and a certain amount of toner is conveyed to the electrostatic latent image by a developing roller to perform development.
After the formation of the toner pattern, on the toner pattern
It is transferred to the paper running of the serial, further toner putter
It is possible to perform printing by fixing on to paper.

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

[0010]

However, according to the prior art having the above-described structure, the rotational speed of the drum assumes the environment and conditions in which the apparatus is used, and the processing capacity of the controller, the processing capacity of the engine, the cost, etc. An almost appropriate speed is set based on the above condition, but this speed is a speed inherent to the device and is not variable.

Further, a constant amount of toner is supplied so as to meet a print pattern having an average print duty. As described above, according to the related art having the above-described configuration, if the print dot density is higher than the above average, the supplied toner becomes insufficient and the print density is reduced.

Therefore, when there is a large amount of data from the information output unit and the number of print dots in one page is large,
For example, in the case where certain data from the information output unit prints one page in black with an image, the toner supply amount is not sufficient and the print is blurred, 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 that the print density is reduced only in this high portion to cause shading, and a constant print density cannot be maintained.

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 that varies for each print data, and reduces the occurrence of shading due to the print dot density. It is an object of the present invention to prevent the problem and realize a constant density printing in a page printer.

[0014]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides an image processing apparatus which processes print information from an information output section in a controller section, and forms an electrostatic latent image on a print drum rotated at a constant speed by an engine section. An image is formed, toner is supplied onto a print drum by rotation of a developing roller, the electrostatic latent image is developed and transferred to a sheet, and the running of the sheet is synchronized with the formation of the electrostatic latent image. in the printing control method of the page printer for printing Te, received by the controller
Rendering print information into data to be actually printed and drawing memory
And the print dot density is calculated from the data stored in the drawing memory and transmitted to the engine unit. The engine unit changes the rotation speed of the developing roller in accordance with the print dot density from the controller unit to change the print drum. It is characterized in that the amount of toner supplied upward is adjusted.

[0015]

With the above arrangement, the present invention expands print information received by the controller into data to be actually printed.
Is the data stored in the drawing memory and the data stored in the drawing memory
For sending to the engine by calculating the al print dot density, the engine adjusts the amount of toner supplied onto the printing drum by varying the rotational speed of the developing roller in accordance with the print dot density from the controller unit, Print dot density
The density of the print density can be prevented from occurring due to the level of the print density , and the print density can always be kept constant, thereby enabling high-quality printing.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. In addition,
In the following description, the same parts as those of the above-described 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 of transmitting information from an information output unit 3 to a controller unit 1 and performing printing based on the information in an engine unit 2 is the same as the above-described conventional example. is there. FIG. 2 is an explanatory diagram for explaining the layer management memory of the embodiment.

In this embodiment, a laser printer having a resolution of 240 DPI (dot per inch) in both the main scanning direction and the sub-scanning direction will be described in the case of printing on A4 size cut sheet. The traveling direction of the sheet is defined as a Y direction, and the direction perpendicular to the Y direction is defined as an X direction. As shown in FIG. 2, the Y direction of one page of paper is virtually 64 dots (1 dot is 1 dot).
/ 240 inches), 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 flowchart showing a processing procedure at the time of starting printing in the embodiment. As shown in FIG.
In the present embodiment, a light emission instruction is issued from the drawing memory 10 to the light emission control unit 15 by a video signal, and before the start of motor driving from the print start control unit 11, the printing start control unit 1 is started.
In step 1, the data written in the drawing memory 10 is read, the print dot density of each layer is calculated, and the
(S301) and transmits it to the engine unit (S30).
2).

FIG. 4 is a flowchart showing the procedure for calculating the print dot density of each layer in this embodiment in 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 this point will be described. First, the top layer number is set in S401, and the total number of dots C in the layer unique to the paper is determined in S402.
At 04, the initial value of the position of the layer N in the Y direction is set to y, and the total number A of printed dots of the layer N is updated. S407, S408
Update the y position and if it is not the end of layer N, S4
05, if it is the end of layer N, S409, S410
From the constant C and the total dot number A of the layer N, the print dot density Vn
(Vn = A / C × 100) is obtained and stored in the layer management memory 17. Further, in S411, it is determined whether or not the layer N is the last layer.
Return to 03. If it is the last layer, the data of 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 a description thereof will be omitted.

FIG. 5 is a flowchart showing a print control processing procedure of the present embodiment. The print control processing of the present embodiment will be described below. The engine unit 2 receives the contents 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 paper running in S503. In S504, the sheet is waited until the photosensitive timing is reached. When the photosensitive timing is reached, the one-line printing drum 12 is exposed in S505, and it is determined whether the end of the paper is reached in S506. Run and end. If it is not the end, it is determined in S507 that the development line is a layer switching portion. If it is not a switching portion, the process returns to S504. 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, according to the present invention, the information
The controller processes the print information from the output unit to form an electrostatic latent image on the print drum rotating at a constant speed by the engine unit, and supplies toner onto the print drum by rotating the developing roller. In a page printer print control method in which an electrostatic latent image is developed and transferred to a sheet, and the travel of the sheet is printed in synchronization with the formation of the electrostatic latent image, the print information received by the controller is actually used.
Develop the data to be printed on the drawing memory and store it in the drawing memory.
Calculates the print dot density from the data stored in the image memory and sends it to the engine. The engine supplies toner to the print drum by changing the rotation speed of the developing roller according to the print dot density from the controller. I try to adjust the amount.

Therefore, according to this, the amount of toner supplied onto the print drum is adjusted by changing the rotation speed of the developing roller according to the print dot density.
The print density can be kept constant at all times by preventing the density of the print density from being changed due to the height of the image, and the effect that high quality printing becomes possible is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one 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 at the time of starting printing according to an embodiment of the present invention.

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

FIG. 5 is a flowchart illustrating 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 illustrating a processing procedure of a conventional editing unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Controller part 2 Engine part 11 Printing start control part 12 Printing drum 13 Printing control part 16 Developing roller 17 Layer management memory

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41J 2/485 B41J 2/44 B41J 29/38 G03G 15/00 303 H04N 1/29

Claims (1)

(57) [Claims] An information processing unit performs data processing on print information from an information output unit , forms an electrostatic latent image on a print drum rotating at a constant speed by an engine unit, and forms an electrostatic latent image on the print drum by rotating a developing roller. In a page printer print control method for supplying toner and developing the electrostatic latent image and transferring the electrostatic latent image to a sheet, and printing the running of the sheet in synchronization with the formation of the electrostatic latent image, the controller unit includes: The data for actually printing the received print information
Data into the drawing memory and store it in the drawing memory.
The print dot density is calculated from the stored data and transmitted to the engine.The engine adjusts the amount of toner supplied to the print drum by changing the rotation speed of the developing roller according to the print dot density from the controller. Printing control method for a page printer.