JP2660087B2 - Electrophotographic printer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electrophotographic printer that can reduce the rotation time of a photosensitive drum when printing in page units.

2. Description of the Related Art Conventionally, in an electrophotographic printer, a charged photosensitive drum is irradiated with a light source to form an electrostatic latent image on a surface thereof, and toner is adhered to the electrostatic latent image to perform development. After that, the toner image is transferred to a recording medium.

Then, the print data input from the terminal is converted into image data, exposure is performed by the image data, and an electrostatic latent image is formed on the photosensitive drum.

FIG. 4 is a schematic configuration diagram of a conventional electrophotographic printer.

In the figure, an electrophotographic printer 1 includes a control unit 3 for receiving print data from a terminal 2 and a printing unit 4 for performing printing.
It is composed of The control unit 3 includes an external connection interface unit such as a Centronics interface, a reception buffer 6, a microprocessor 7, a font memory 8, and an image memory 9.

Here, the print data from the terminal 2 is supplied to the reception buffer 6 via the external connection interface unit 5. A printing paper supply unit 11a for automatically supplying a fixed printing paper 24 is provided on the bottom and right side of the printing unit 4.
11b are provided respectively.

A photoconductor drum 12 having a photoconductor surface formed on the outer periphery, a charger 27 for uniformly charging the photoconductor surface, and an electrostatic latent image corresponding to image data for printing on the photoconductor surface are provided inside the printing unit 4. Light emitting diode array 13, developing device 14,
A transfer unit 15 and a fixing unit 16 are provided. Further, on the left side of the printing unit 4, there is provided a discharge unit 17 for discharging the printing paper 24 on which printing has been completed.

The printing unit 4 includes a microprocessor 18 that communicates with the control unit 3 and controls the entire printing unit 4.
Cover open switch that detects whether the cover has been opened
19 are provided.

Further, a bidirectional serial interface 20 for communication between the control unit 3 and the printing unit 4 and a signal line for transferring and controlling print data formed of dot image data are provided between the control unit 3 and the printing unit 4. Video interface with
Connected at 21.

The electrophotographic printer 1 configured as described above operates as follows.

When print data is input from a host computer (not shown) through the terminal 2 and the external connection interface unit 5, the electrophotographic printer 1 takes the print data into the reception buffer 6. Next, the microprocessor 7 reads the character code included in the print data, and refers to the font memory 8 to create print image data. This print image data is written to the image memory 9.
In the image memory 9, for example, print image data for one page of print paper is edited and stored.

When the print data taken into the reception buffer 6 is image data, the microprocessor 7 writes the image data at a predetermined address of the image memory 9 as it is. In the case of business graphic printing or the like, since the print data is sent from the host computer in the form of a graphic command, the microprocessor 7 edits and calculates the image data and writes it directly into the image memory 9.

In this manner, when the analysis and editing of the print image data are completed, the print paper 24 is changed to one of the print paper supply units.
It is transported from 11a and 11b.

In parallel with this, image data for printing is supplied by the microprocessor 7 to the light emitting diode array 13 via the video interface 21, and the light emitting diode array
13 is driven, and an electrostatic latent image is formed on the outer periphery of the photosensitive drum 12. When the photosensitive drum 12 rotates in the direction of the arrow 12a, the electrostatic latent image is developed by the developing device 14, and the transfer device 15
Is transferred to the printing paper 24 at. Printing paper 24 is a fixing device
The toner is fixed at 16 and discharged to the discharge unit 17.

In this way, information based on the print data received from the host computer is printed on the printing paper 24.

FIG. 5 is an operation flowchart for explaining the paper supply timing of a conventional electrophotographic printer, FIG. 6 is a detailed diagram for explaining the paper transport of the printing unit, and FIG. 7 is a print paper transport timing chart.

In FIG. 7, R _i (i = 1, 2,...) Is an i-page reception process, and E _i (i = 1, 2,...) Is an i-page editing process.

Steps-First, when print data is sent from the host computer, the microprocessor 7 determines whether the print data is print data at the stage where the print data is accumulated in the reception buffer 6 of the control unit 3.

Step In addition, the serial interface 20
Then, the presence / absence of a sheet supply enable signal sent from the printing unit 4 via the printer 1 is determined, and if possible, a sheet supply command is sent out via the serial interface 20. Upon receiving the paper supply command, the microprocessor 18 of the printing unit 4 turns on the hopping roller motor 25 as shown in FIG. 6A, and starts taking out the printing paper 24 from the paper supply units 11a and 11b.

The printing paper 24 taken out of the paper supply units 11a and 11b is detected by the entrance sensor (S ₀ ) 26 and is conveyed to the position of the registration roller clutch 127 as shown in FIG. 6B. At the same time, the hopping roller motor 25 is turned off, and an actual print enable signal is sent to the control unit 3 via the serial interface 20.

During this time, the step control unit 3 performs the receiving process of the page, and when the receiving process of one page is completed, the process starts the editing process.

Step ~ When the editing process for one page is completed,
It is determined whether or not the printing unit 4 is capable of actual printing. If the printing is possible, the actual printing start command is sent to the printing unit 4 and the actual printing process such as dot image data transfer is started. In the step, if the reception of one page is completed before the sheet supply enable signal is sent from the printing unit 4, the editing process is started immediately from the step, but the sheet supply enable signal is sent after the edit process is started. Is sent to the printing unit 4.

When the printing section 4 receives the actual printing start command, the printing section 4 turns on the registration roller clutch 127 and restarts the sheet conveyance. As shown in FIG. 6 (c), when the time _tw has elapsed after resumption of sheet conveyance, a request for print data is made to the control unit 3 for writing print data on the photosensitive drum 12. When dot image data is sent from the control unit 3 to the light-emitting diode array 13 via the video interface 21, writing to the photosensitive drum 12 is performed, and the dot to the photosensitive drum 12 is synchronized with the conveyance paper. Writing of image data is sequentially performed. The photoreceptor drum 12 rotates, and the transfer unit 15 prints the printing paper 24 in the order in which the writing is performed.
And the transfer of the page is completed. When the transfer of the page is completed and the printing paper 24 passes through the entrance sensor (S ₀ ) as shown in FIG. 6D, the registration roller clutch 127 is turned off, and the printing paper is supplied for the next page. Get ready.

(Problems to be Solved by the Invention) However, in the above-described conventional electrophotographic printer, when printing print data that requires a long time for editing processing, the photosensitive member is transmitted until an actual print start command is transmitted. Since the drum continues to rotate, the degree of wear of the photosensitive layer on the surface of the photosensitive drum becomes extremely large, and the developer inside the developing device is significantly deteriorated, so that the life of these consumables is shortened.

The present invention solves the above-mentioned problems of the conventional electrophotographic printer, and the photosensitive layer on the surface of the photosensitive drum is significantly worn, and the developer inside the developing device is significantly deteriorated. An object of the present invention is to provide an electrophotographic printer that does not become short.

(Means for Solving the Problems) For this purpose, the present invention provides a control unit for generating image data by performing a receiving process and an editing process on a page basis based on print data from an external device. A printing unit for performing printing in accordance with the transmitted image data.

The control unit is configured to determine, when the transfer of one page is completed, whether or not the reception processing of the next page and the editing processing of the next page are completed, and based on a determination result by the determination means. If both the next page receiving process and the next page editing process have been completed, the subsequent mode is switched to the first mode, and either the next page receiving process or the next page editing process is completed. If not, means is provided for stopping the rotation of the photosensitive drum and switching the subsequent mode to the second mode.

Further, the printing unit generates a sheet supply enable signal indicating that the printing sheet can be conveyed and sends the signal to the control unit. Transport means for sending the toner to the registration roller.

And in the said 1st mode, the said control part is:
When the receiving process is started, a paper supply command is generated based on the paper supply enable signal, and the paper supply command is sent to the printing unit.

In the second mode, when the editing process is completed, the control unit receives the sheet supply enable signal, restarts rotation of the photosensitive drum, and based on the sheet supply enable signal, issues a sheet supply command. And sends the sheet supply command to the printing unit.

(Operation) According to the present invention, as described above, in the electrophotographic printer, based on print data from an external device, a control unit that performs reception processing and editing processing in page units to generate image data; A printing unit for performing printing in accordance with the image data sent from the control unit.

The control unit is configured to determine, when the transfer of one page is completed, whether or not the reception processing of the next page and the editing processing of the next page are completed, and based on a determination result by the determination means. If both the next page receiving process and the next page editing process have been completed, the subsequent mode is switched to the first mode, and either the next page receiving process or the next page editing process is completed. If not, means is provided for stopping the rotation of the photosensitive drum and switching the subsequent mode to the second mode.

Further, the printing unit generates a sheet supply enable signal indicating that the printing sheet can be conveyed and sends the signal to the control unit. Transport means for sending the toner to the registration roller.

And in the said 1st mode, the said control part is:
When the receiving process is started, a paper supply command is generated based on the paper supply enable signal, and the paper supply command is sent to the printing unit.

In the second mode, when the editing process is completed, the control unit receives the sheet supply enable signal, restarts rotation of the photosensitive drum, and based on the sheet supply enable signal, issues a sheet supply command. And sends the sheet supply command to the printing unit.

In this case, the control unit generates image data by performing reception processing and editing processing in page units based on print data sent from an external device. When receiving the image data from the control unit, the printing unit performs printing according to the image data.

Further, when the transfer of one page is completed, the control unit determines whether the reception processing of the next page and the edit processing of the next page are completed, and based on the determination result, the reception processing of the next page. When both the editing process of the next page and the editing process of the next page have been completed, the subsequent mode is switched to the first mode, and when either the receiving process of the next page or the editing process of the next page has not been completed, The rotation of the drum is stopped, and the subsequent mode is switched to the second mode.

And in the said 1st mode, the said control part is:
At the start of the receiving process, when a paper supply enable signal is sent from the printing unit, a paper supply command is generated, and the paper supply command is sent to the printing unit. The printing unit sends the printing paper to the registration rollers according to the paper supply instruction. Therefore, when the print data is received, the printing paper is supplied.

Further, in the second mode, when the paper supply enable signal is sent from the printing unit when the editing process is completed, the control unit restarts the rotation of the photosensitive drum, and outputs the paper supply enable signal. A paper supply instruction is generated based on the instruction, and the paper supply instruction is sent to the printing unit. The printing unit sends the printing paper to the registration rollers according to the paper supply instruction. Therefore, while the second mode is continued, the printing paper is not supplied even after the reception processing is completed until the editing processing of the next page is completed.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an electrophotographic printer showing an embodiment of the present invention.

In the figure, an electrophotographic printer 51 includes a control unit 53 that receives print data from a terminal 2 and a printing unit 54 that performs printing.
It is composed of The control unit 53 includes an external connection interface unit 5 including a Centronics interface, a reception buffer 6, a microprocessor 7, a font memory 8, and an image memory 9.

Here, the print data from the terminal 2 is supplied to the reception buffer 6 via the external connection interface unit 5. Further, a printing paper supply unit 11a, which automatically supplies the standard printing paper 24, is provided on the bottom and the right side of the printing unit 54.
11b are provided respectively.

Also, inside the printing unit 54, a photoreceptor drum 12 having a photoreceptor surface formed on the outer periphery, a charger 27 for uniformly charging the photoreceptor surface, and an electrostatic latent image corresponding to printing image data on the photoreceptor surface are provided. Light emitting diode array 13, developing device 14,
A transfer unit 15 and a fixing unit 16 are provided. Further, on the left side of the printing unit 54, there is provided a discharge unit 17 for discharging the printing paper 24 on which printing has been completed.

The printing unit 54 includes a microprocessor 18 that communicates with the control unit 53 and controls the entire printing unit 54.
Cover open switch that detects whether the cover has been opened
19 are provided.

Further, between the control unit 53 and the printing unit 54, a bidirectional serial interface 20 for performing communication between them and a signal line for transferring and controlling print data formed of dot image data are provided. Video interface with
Connected at 21.

FIG. 2 is an operation flowchart for explaining the sheet supply timing, and FIG. 3 is a sheet conveyance timing chart.

In the figure, R _i (i = 1,2,...) Is an i-page receiving process, and E _i (i = 1,2,...) Is an i-page editing process.

Steps-First, when print data is sent from the host computer, the microprocessor 7 determines whether the print data is print data at a stage where the print data is accumulated in the reception buffer 6 of the control unit 53.

Step In addition, the serial interface 20
Then, the presence / absence of a sheet supply enable signal transmitted from the printing unit 54 via the printer unit 54 is determined, and if possible, a sheet supply command is transmitted via the serial interface 20. Upon receiving the paper supply command, the microprocessor 18 of the printing unit 54 turns on the hopping roller motor 25 as shown in FIG. 6A, and starts taking out the printing paper 24 from the paper supply units 11a and 11b.

The printing paper 24 taken out from the paper supply units 11a and 11b
Is detected by the entrance sensor (S ₀ ) 26 and is conveyed to the position of the registration roller clutch 127 as shown in FIG. 6B. At the same time, the hopping roller motor 25 is turned off and the control unit 53 is connected via the serial interface 20.
To send an actual print enable signal.

The step control unit 53 performs a reception process during that time,
When the reception process for one page is completed, the editing process starts next.

When the editing process for one page is completed, the control unit 53 determines whether or not the printing unit 54 is capable of actual printing.
To the actual printing process such as dot image data transfer. In the step, the paper supply enable signal is
If the reception processing of one page is completed before being sent from the printer 54, the editing processing starts immediately from the step. However, when a paper supply enable signal is sent after the editing processing is started, a paper supply command is sent to the printing unit 54. Send out.

Upon receiving the actual printing start command, the printing unit 54 turns on the registration roller clutch 127 and restarts the conveyance of the printing paper 24. As shown in FIG. 6 (c), when after resumption time t _w has elapsed, the printing unit 54 makes a request for print data to the control unit 53. Video interface from the control unit 53
When the dot image data is sent to the light-emitting diode array 13 via 21, the writing to the photosensitive drum 12 is performed, and the writing of the dot image data to the photosensitive drum 12 is synchronized with the printing paper 24. It is performed sequentially. When the photosensitive drum 12 rotates, the transfer is performed on the printing paper 24 by the transfer unit 15 in the order in which the writing is performed, and the transfer for one page is completed. When the transfer for one page is completed, the printing paper 24 is moved to the entrance sensor (S ₀ ) as shown in FIG.
After passing through 26, the registration roller clutch 127 is turned off, and preparation for supplying the printing paper 24 for the next page is started.

Steps-After the actual printing process is completed, when the printing unit 54 starts preparing for supplying the printing paper for the next page, the microprocessor 18 determines whether the editing of the next page is completed for the microprocessor 7. Make an inquiry. In response to an inquiry as to whether or not the editing processing of the next page has been completed, the microprocessor 7 determines whether or not the editing of one page has been completed, similarly to the previous page. Without stopping printing paper supply preparation for the next page. If the editing has not been completed, a drum motor stop command is sent to the microprocessor 18.

The microprocessor 18 enters a drum motor stop sequence based on the drum motor stop command. If the next page data has not been received, the editing is of course not completed. In this case, it is determined in step whether or not the receiving process is completed, and a process for stopping the drum motor is performed.

Thereafter, this mode is maintained, and the processing of the sheet supply determination in the step and the processing of sending the sheet supply command in the step are invalidated. If the editing time of the next page becomes equal to or less than the predetermined time, the mode is set to supply the sheet by starting the reception, and the process of the sheet supply determination in the step and the process of sending the sheet supply command in the step are invalidated.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the gist of the present invention.
They are not excluded from the scope of the present invention.

(Effects of the Invention) As described above, according to the present invention, in an electrophotographic printer, control for performing reception processing and editing processing in page units based on print data from an external device to generate image data. And a printing unit for performing printing in accordance with the image data sent from the control unit.

The control unit is configured to determine, when the transfer of one page is completed, whether or not the reception processing of the next page and the editing processing of the next page are completed, and based on a determination result by the determination means. If both the next page receiving process and the next page editing process have been completed, the subsequent mode is switched to the first mode, and either the next page receiving process or the next page editing process is completed. If not, means is provided for stopping the rotation of the photosensitive drum and switching the subsequent mode to the second mode.

Further, the printing unit generates a sheet supply enable signal indicating that the printing sheet can be conveyed and sends the signal to the control unit. Transport means for sending the toner to the registration roller.

And in the said 1st mode, the said control part is:
When the receiving process is started, a paper supply command is generated based on the paper supply enable signal, and the paper supply command is sent to the printing unit.

In the second mode, when the editing process is completed, the control unit receives the sheet supply enable signal, restarts rotation of the photosensitive drum, and based on the sheet supply enable signal, issues a sheet supply command. And sends the sheet supply command to the printing unit.

In this case, in the first mode, when the print data is received, the printing paper is supplied. However, in the second mode, the reception processing ends until the editing processing of the next page ends. No printing paper is supplied.

Therefore, when print data that requires a long time to perform the editing process is on the second and subsequent pages, the rotation of the photosensitive drum is stopped when the transfer is completed in the printing of the previous page. The body drum is not rotated more than necessary. As a result, the photosensitive layer on the surface of the photosensitive drum is not significantly worn and the developer inside the developing device is not significantly deteriorated, so that the life of the consumable can be extended.

When the developing device, the fixing device, and the like have a structure that rotates with the operation of the drum motor, the life of the developing device, the fixing device, and the like can be extended.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an electrophotographic printer showing an embodiment of the present invention, FIG. 2 is an operation flowchart for explaining sheet supply timing, FIG. 3 is a sheet conveyance timing chart, and FIG. Schematic configuration diagram of a photo printer,
FIG. 5 is a flow chart for explaining the paper supply timing of the conventional electrophotographic printer, FIG. 6 is a detailed diagram for explaining the paper transport of the printing unit, and FIG. 7 is a print paper transport timing chart. 2 ... terminal, 6 ... reception buffer, 7, 18 ... microprocessor, 53 ... control unit, 54 ... printing unit.

Claims (1)

(57) [Claims] 1. A control unit for generating image data by performing a receiving process and an editing process on a page basis based on print data from an external device, and (b) an image data sent from the control unit. (C) when the transfer of one page is completed, the control unit determines whether the reception processing of the next page and the editing processing of the next page are completed. When both the next page receiving process and the next page editing process have been completed based on the determination result by the determining unit and the determination result, the subsequent mode is switched to the first mode, and the next page receiving process is performed. Means for stopping the rotation of the photosensitive drum when any one of the editing processes of the next page is not completed, and for switching the subsequent mode to the second mode; The unit generates a sheet supply enable signal indicating that the printing sheet can be conveyed and sends the signal to the control unit, and when receiving a sheet supply command from the control unit, sends the printing sheet to the registration roller. (E) in the first mode, the control unit generates a paper supply command based on the paper supply enable signal when the reception process is started, and prints the paper supply instruction. (F) In the second mode, upon completion of the editing process, the control unit receives the sheet supply enable signal, restarts rotation of the photosensitive drum, and outputs the sheet supply enable signal An electrophotographic printer that generates a sheet supply command based on the received sheet supply command and sends the sheet supply command to a printing unit.