JPH08123257A - Electrophotographic equipment - Google Patents

Abstract

(57) [Abstract] [Purpose] To reduce the amount of toner consumption for electrophotographic devices. The electrophotographic apparatus has a toner consumption saving mode, and the toner saving mode can save the toner consumption regardless of the remaining amount of toner.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used when the amount of remaining toner is low and it is desired not to consume much toner, or when accurate printing such as test printing is not required and the toner is not consumed too much. The present invention relates to a laser beam exposure type electrophotographic apparatus such as a printer, a facsimile, and a copying machine that can print while saving toner consumption.

[0002]

2. Description of the Related Art Conventionally, for example, in a printer apparatus using an electrophotographic system, a method has been adopted in which a warning is issued when the toner remaining amount is low, and an operator problem due to toner shortage or the like is avoided. However, in reality, the operator did not replenish the toner for this warning, but replenished it when the toner ran out. Therefore, there is a demand for a toner saving mode in which the toner consumption amount is reduced in order to increase the time period from the occurrence of this warning to the time when the toner runs out, and a technique for it is invented.

In Japanese Patent Laid-Open No. 1-133075, the toner saving mode is selected by the toner saving mode SW, and when the toner remaining amount becomes less than a certain amount, the developing width is shortened in order to save the consumption amount. However, a technique for reducing the image density is described. In this technology, as shown in FIG. 8, two drivers, a driver 2 for reducing the driving power of the laser diode and a driver 1 for a normal driving current, are prepared for the driver of the laser diode. Select the current driver 1 and reduce the drive current when the toner saving mode is ON. Driver 2
Was to choose.

Further, in Japanese Patent Laid-Open No. 1-144574,
A technique for reducing toner consumption by thinning out image data every 1 dot (changing black data into white data every 1 dot) is described. This can be realized by a circuit as shown in FIG. Further, in recent years, there is a method of reducing the toner consumption amount by eliminating the black dot by such a complicated process as pattern matching so as not to damage the entire image.

[0005]

According to the above-mentioned prior art, the number of parts is increased and the cost is increased because, for example, two laser diode drivers are prepared. still,
The driver is an analog product, which is difficult to make into an LSI.

Further, in other conventional techniques, the toner consumption amount is reduced by thinning out the dots of the basic data, but this has a drawback that the image of the basic data is lost. That is, the original intention of the data may not be transmitted.

Further, regarding the general prior art, the toner saving mode is either ON or OFF, and it is impossible to adjust the step of reducing the toner consumption amount. Therefore, it is impossible to finely save the toner consumption amount. It was

[0008]

An electrophotographic apparatus according to claim 1, wherein the electrophotographic apparatus is a laser beam exposure type electrophotographic apparatus having a toner consumption saving mode for adjusting a toner consumption amount, the toner consumption saving mode is a toner. The present invention is an electrophotographic apparatus, which saves toner consumption regardless of the remaining amount of toner.

According to a second aspect of the present invention, in the toner consumption saving mode, the toner consumption amount is reduced by shortening the data width per dot under the control of the controller. Is an electrophotographic device.

According to another aspect of the electrophotographic apparatus, there are at least two types of data width per dot.
3. The electrophotographic apparatus according to claim 2, wherein the data width can be selected.

In the electrophotographic apparatus according to the present invention, the toner consumption saving mode uses a clock adjusted by a jitter adjusting circuit, does not change the total number of dots of the basic data, and is data synchronized with the basic data. The electrophotographic apparatus according to claim 1, wherein:

[0012]

According to the structure of claim 1, the amount of toner consumption is saved except when the remaining amount of toner is low, that is, when accurate printing is not necessary for trial printing and the toner is desired to be saved. it can.

According to the second aspect of the present invention, the data width per dot can be shortened by adding a small number of Rojita circuits of the controller, and the toner consumption amount can be saved.

According to the third aspect of the present invention, by having the step of the toner saving mode, the operator selects the toner consumption amount and the printing state at that time according to the state of the remaining amount of toner and the confirmation state of the trial printing. You can do it.

According to the structure of claim 4, since the total dot number of the basic data is not changed but only the one-dot width of the basic data is reduced, there is no image loss and the printing state is the same as the basic data. Printed without any difference. Further, since it can be realized by a simple low jitter circuit, it can be made into an LSI.

[0016]

Embodiments of the present invention will be described with reference to FIGS.

FIG. 7 is an overall configuration diagram of the printer according to the present invention. The printer analyzes the data transmitted from the HOST, and when the data for one page is prepared, the mechanical controller starts printing. Upon start of this printing, the mechanical controller conveys the paper to the OPC drum 703 by the conveyance roller 701. This drum has 7
Laser light is emitted from the optical unit 04. Corona discharge adheres to the irradiated portion from the DV cartridge 705. The toner attached to the drum is transferred to the paper conveyed to the drum by the transfer charger 702. The toner that has not been transferred is stored in the waste toner BOX 706 as waste toner. The paper on which the toner has been transferred is heated by the heater lamp 707 to be thermally fixed on the toner paper. The fixed paper is 708
The paper is output by the paper output roller.

FIG. 1 shows a system block diagram of the present invention in a laser printer. Among these, 110 is a controller, and the controller is from HOST (computer) to parallel, RS I / F (serial I / F)
Analyze the printer control instruction code communicated by
Accordingly, the print data for one page is changed to dots (hereinafter,
dot) pattern and stored in a memory called a page buffer. Further, it is a part for performing image control from the memory and transmitting it as serial data to the engine. The internal operation of this controller 110 is HOST
The data transmitted by RS I / F from the serial I / F
The data received by the F ports 107 and 108 and transmitted by the parallel I / F is the parallel I / F port 109.
It is received by the CPU 100 which is operated by the oscillator 101 through the data bus. CPU 100 is
The instruction is executed by the ROM 103 in which the program is stored, and the data fetched from 108 and 109 is stored in C
The PU100 analyzes and analyzes the dot pattern of one page by RA.
Store in M104. Here, 102 is a decoder that generates a select signal for each unit, and 105 is a general-purpose I / O port.

Reference numeral 102 denotes an engine control unit that controls electrophotographic printing. Reference numeral 122 denotes an operation panel, which is usually composed of several KEYs and LEDs, and an LCD for display. The microprocessor 121 reads the information from the KEY, controls each unit according to this information,
Displayed by LED and LCD as required. Reference numeral 123 indicates a motor, a clutch, and a solenoid required for the electrophotographic method. This is controlled by the microprocessor 121.

The controller analyzes the command data from the HOST, stores the data for one page, and sends a print start signal to the engine section when printing is possible. If the engine is in a printable state, it shifts to a printing operation and horizontally synchronizes and sends HSYNC to the controller. In the controller, in sync with this HSYNC,
Data for one page is sent to the engine serially line by line. Here, the controller 106 is an image control unit, and the CPU 100 sends one page of data from the memory to this. The engine sends the sent serial data to the laser diode 125 through the laser diode driver 124 to irradiate the laser on the drum and print it.

The image control unit 106 is a block diagram of the present invention, and a block diagram is shown in FIG. Reference numeral 202 is an oscillator for creating a video clock VCLK for sending each dot in synchronization with the laser. Reference numeral 201 denotes a jitter adjustment circuit, which is a circuit for keeping the print start position constant. Usually 1/4
Make it constant with an error within dot. This circuit creates VCLK that is synchronized so that the error is within 1/4 dot at the edge of the horizontal synchronizing signal HSYNC. Usually 1 / 4d
To make the error within ot, 4 times the frequency of VCLK is 2
It will be 02. Reference numeral 210 is a left margin counter, which is a counter for opening a space from the edge of the paper to printing, and can be set by the operator. Reference numeral 203 denotes a FIFO memory, which can perform writing and reading asynchronously. CPU10
0 is the data stored in the RAM 104 in the FIFO 203
Usually write several lines at a time. The reading is read in synchronization with VCLK. The read data is converted to serial data through the parallel-serial converter 204. This data is 1/4 by 205 (1/4 dot generation circuit)
A dot is generated, a half dot is generated by 206 (1/2 dot generation circuit), and a 3/4 dot is generated by 207 (3/4 dot generation circuit). Each generation circuit has VCLK and 1 / 2VCLK, and a few gate circuits and F
Created with / F.

FIG. 4 shows an example of a 1/4 dot generation circuit. These four serial data are C by the selector 208
It is selected by a select signal from the PU 100 and sent to the engine section.

The flow of the above selection method is shown in FIG. That is, the type of saving mode is set to host data and K
Reading from EY data (S31, S32), original data, 1/4 data, 1/2 according to the read data
Which to select from data or 3/4 data CPU
Judge. As a result, the select signal is generated (S33 to S37).

FIG. 5 is a timing chart showing the data width at each stage of the toner saving mode.
A is the original data, and this data width corresponds to one cycle of VCLK, and this means a data width of 1 dot. This signal is low active and is black data when "0" and white data when "1". / DATA
In (1/4), as you can see by comparing with / DATA,
The data width is 1/2 VCL for black data (when it is "0")
It is a half-round machine of K (1/4 cycle of VCLK). That is, the black data has a width of 1/4 dot. Similarly, / DATA (1/2), / DATA (3
It can be seen that / 4) also has a half dot width and a 3/4 dot width, respectively. As can be seen, in the data whose data width has been reduced, the black data of the original data is simply reduced, and there are no missing dots. As a result, it is possible to realize printing without image loss. Further, as the data width is reduced, the diameter of the dots emitted by the laser is reduced, and accordingly, the amount of toner attached to the drum is reduced, and the toner consumption amount can be reduced.

FIG. 6 shows an example of printing in each saving mode. In this way, it can be seen that the dot size is smaller for each saving mode. If the dot size becomes smaller, the laser irradiation diameter becomes smaller, the amount of toner adhering to the drum decreases, and the amount of toner consumption decreases.

[0026]

According to the first aspect of the present invention, the amount of toner consumption is different from when the remaining toner amount is low, that is, when accurate printing is not required for trial printing and the toner is desired to be saved. Can save

According to the second aspect of the invention, the data width per dot can be shortened by adding a few logic circuits of the controller, and the toner consumption amount can be saved. Further, since this circuit is composed of logic, the operation is stable and the cost is low. According to the third aspect of the invention, by having the step of the toner saving mode, the operator can select the toner consumption amount and the printing state at that time according to the state of the remaining amount of toner and the confirmation state of the trial printing. it can.

According to the invention described in claim 4, since the total dot number of the basic data is not changed but only the one-dot width of the basic data is reduced, there is no image loss and the printing state is the same as the basic data. Printed without any difference. Therefore, the basic data can be faithfully reproduced. Since this can be realized by a simpler logic circuit, it can be implemented as an LSI and this function can be achieved at low cost.

[Brief description of drawings]

FIG. 1 is a system block diagram of the present invention.

FIG. 2 is a block diagram of an image control circuit.

FIG. 3 is a flowchart showing the operation of the present invention.

FIG. 4 is a circuit diagram for controlling a data width of ¼ dot.

FIG. 5 is a timing chart showing a data width at each stage of the toner saving mode.

FIG. 6 is a diagram showing an example of printing with a data width at each stage of the toner saving mode.

FIG. 7 is an overall configuration diagram of a printer according to the present invention.

FIG. 8 is a block diagram of a prior art having two laser diode drivers.

FIG. 9 is a circuit diagram of a conventional technique for saving toner by thinning out dots.

[Explanation of symbols]

 100 CPU 101 Oscillator 102 Decoder 103 ROM 104 RAM 105 General Purpose I / D Port 106 Image Control Unit 107 Serial I / F Port 108 Serial I / F Port 109 Parallel I / F Port 110 Controller 120 Engine Control Unit 121 Microprocessor 122 Operation Panel 123 Motor 124 Laser Diode Driver 125 Laser Diode 201 Jitter Adjustment Circuit 202 Oscillator 203 FIFO Memory 204 Parallel Serial Converter 205 1/4 Dot Generation Circuit 206 1/2 Dot Generation Circuit 207 3/4 Dot Generation Circuit 208 Selector 701 Conveyor Roller 702 Transfer charger 703 OPC drum 704 Optical unit 705 DU cartridge 706 Waste toner BOX 70 Heater lamp 708 Desi roller

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area H04N 1/29 E

Claims (4)

[Claims] 1. In a laser beam exposure type electrophotographic apparatus having a toner consumption saving mode for saving the consumption of toner, the toner consumption saving mode executes saving of toner consumption regardless of the remaining amount of toner. An electrophotographic device characterized by. 2. The electrophotographic apparatus according to claim 1, wherein the toner consumption saving mode reduces the toner consumption amount by shortening the data width per dot under the control of the controller. 3. The electrophotographic apparatus according to claim 2, wherein there are at least two types of data width per dot, and the data width can be selected. 4. The toner consumption saving mode uses a lock adjusted by a jitter adjustment circuit to create data that is in synchronization with the basic data without changing the total number of dots of the basic data. The electrophotographic apparatus according to claim 1.