JP3238739B2 - Image forming apparatus and method of controlling image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for fixing an image on recording paper using a heat fixing means in a copying machine, a laser beam printer, a facsimile or the like.

[0002]

2. Description of the Related Art In a conventional image forming apparatus, when code data of an image is received from an external device, it is analyzed by a video controller of an image processing means, developed from the code data into bitmap image data, and stored in a bitmap memory. I will remember. After the development of the image data for one page is completed, a print start signal for instructing the printer engine to start a print operation is transmitted to the printer engine.

When the printer engine receives the print start signal, it starts driving the polygon motor and the fixing unit, and performs pre-processing necessary for image formation, for example, processing for uniformly charging the surface of the photosensitive drum. Start feeding the printing paper, form a latent image in synchronization with the printing paper by the electrostatic copying method, develop it into a toner image, transfer it to the printing paper, and fix the toner image on the paper with the fixing device. Form an image.

When an image is formed in accordance with the above-described process, the time from when the printer engine receives the print start signal to when the print operation is completed (hereinafter, referred to as first print time) becomes long. The provision of the print start signal hastened the activation of the printer engine to shorten the first print time.

[0005]

However, the prior art described above has the following problems in that the start of the printer engine is accelerated by the pseudo print start signal. (1) When the fixing unit is energized for a time longer than the time required for the printing operation, the power consumption increases and the temperature inside the apparatus also increases. (2) By energizing the fixing device for a time longer than the time required for the printing operation, the life of the fixing device is shortened and the reliability is reduced. (3) The cost of the product has been increased in order to extend the life of the fixing device. (4) In the case where the transport time from the paper feed port to the image writing position is set longer than the time at which the fixing device reaches a printable temperature, the power consumption by the fixing device and the temperature rise inside the device become extremely large. It was getting bigger.

As described above, conventionally, there has been a problem that power consumption is increased because the first print time is shortened.

[0007] The present invention has a short first print time.
Reduce the total power supply time to the fuser as much as possible while reducing the size
This reduces power consumption and reduces fuser
An image forming apparatus capable of realizing a longer life and
Another object of the present invention is to provide a method for controlling an image forming apparatus.
It is.

[0008]

According to the present invention, there is provided a host computer.
Receiving means for receiving code data from the device, and the receiving means
Expands the code data received by the user into video data
Means, paper feeding means for feeding paper, and
The paper feeding means feeds paper based on the input video data.
Forming means for forming a toner image on torn paper, and the forming means
Fixing means for fixing the toner image formed by the step on the paper
And after the receiving means has received the code data.
Before the expansion processing for one page by the expansion means is completed.
And before the energization of the fixing means is started.
A predetermined signal generating means for generating a predetermined signal at the timing of
Stage and the predetermined signal generated by the predetermined signal generating means
In synchronism with the
Paper feed control means for controlling to start a paper operation;
After the paper feeding means starts the paper feeding operation,
Power supply control means for controlling power supply to start
An image forming apparatus .

With the above arrangement, the first print
The time can be shortened, and the total
The power-on time can be reduced as much as possible.
It is possible to reduce power consumption and extend the life of the fuser.
it can.

[0010]

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

The image forming apparatus includes a video controller 4 for processing input data from a host computer 30.
0, and a printer engine unit 50 that performs image forming processing. The printer engine unit 50 has an engine control unit 25 that controls the entire processing process.
A scanner unit 52 for scanning a laser beam based on the input image data, a fixing unit 53 for thermally fixing the toner image transferred to the recording paper, and a paper feed roller 10 for controlling the supply of the recording paper. , Registration roller 11
, A registration sensor 17, a paper feed sensor 12, a top sensor 16, and the like.

FIG. 2 is a block diagram showing the configuration of the video controller 40 in this embodiment.

In FIG. 1, a CPU 16 has a ROM 18 storing a program and a RAM 19 used as a register or the like, and transmits image information (code data) coded from a host computer or the like via an external interface 17. And receives it and sends it to the image processing unit 20
Send to

The image processing section 20 stores the received code data in the RAM 21 and analyzes the code data to read data from the character font stored in the ROM 22 as necessary, and converts the code data into a dot image. Converts to video data and stores it in frame memory 2
3 is stored.

When one page of video data is stored in the frame memory 23, the CPU 16 sends a print command to the engine control unit 25 via the video interface 24, and the main / sub scanning from the engine control unit 25 is performed. The video data stored in the frame memory 23 is sequentially transmitted to the engine control unit 2 in synchronization with the synchronization signal.
5

FIG. 3 is a sectional view showing the structure of the printer engine unit 50 in this embodiment. In FIG. 3, the same components as those in FIGS. 1 and 2 are denoted by the same reference numerals.

In this embodiment, the printer body 1 is a laser beam printer. The optical unit 3
The laser beam is modulated by the video data transmitted via the video interface 24,
Drum 2 by a polygon mirror (not shown)
Scan above.

The charger 5 charges the photosensitive drum 2 uniformly, and the developing unit 6 develops the electrostatic latent image on the photosensitive drum 2 into a toner image. The transfer unit 7 transfers the toner image on the photosensitive drum 2 to paper.
The cleaner 8 collects the toner remaining on the photosensitive drum 2 after the transfer.

The paper feed roller 10 feeds the paper loaded on the paper cassette 9. The registration roller 11 conveys the fed paper to the transfer position, stops the paper upon detecting that the paper has reached the registration sensor 17, and stops the paper. The paper feed sensor 12 detects the presence or absence of the fed paper.

The fixing device 13 fixes the toner image transferred onto the sheet by heating and pressing. The paper discharge sensor 14 detects the presence or absence of paper discharged from the fixing device 13. The sheet is discharged to the discharge tray 15.

The top sensor 16 includes a control unit 25
The timing for transmitting a sub-scan synchronization signal for notifying the start of printing is determined.

Next, the printing operation and the fixing unit temperature control operation in such a configuration will be described.

FIG. 4 is a flowchart showing the operation of the video controller 40 and the engine control unit 25, and FIG. 5 is a flowchart showing the operation of the printer engine unit 50. FIG. 6 is a timing chart showing the timing of the printing operation.

First, in FIG. 4, in step S101, the video controller 40 waits until code data of an image is transmitted from an external device such as a host computer. When the code data is received, the engine unit 50 starts pseudo printing. In order to issue a command, the pseudo print start signal, which is a signal of the video interface 24, is set to "L" (S102).
The image processing unit 20 expands the code data into video data (S103).

Next, it is determined whether or not the development from the code data to the video data has been completed for one page (S104).
If not completed, the process proceeds to S103, and if completed, the process proceeds to S105.

In step S105, the print start signal, which is a signal of the video interface 24, is set to "L" in order to instruct the engine unit 50 to start printing, and the engine unit 50 starts the feeding operation to start the printing operation. Then, driving of the polygon motor is started, and pre-processing such as uniformly charging the surface of the photosensitive drum 2 is performed.
Waits for a sub-scan synchronization signal to be transmitted via the video interface 24.

When the sub-scan synchronization signal is received in S106, the print start signal is set to "H" in S107,
In step 08, printing for one page is performed, and the flow advances to step S101.

On the other hand, in FIG. 5, in the engine unit 50, immediately after the power is turned on, the process control is stopped in order to stop all the driving systems in order to reduce power consumption (S201). Then, the print start signal is monitored (S2
02) If "L", the process proceeds to S212 described later.
If the print start signal is not "L", the flow shifts to S203.

In step S203, the pseudo print start signal "L" is monitored. If the signal is not "L", the process returns to step S201, where "L" is set.
If so, the process proceeds to S204 and thereafter. In this S204,
The cassette paper 9 is fed by the paper feed roller 10, the driving of the polygon motor in the optical unit 3 is started, and the pre-processing for starting the printing operation is performed.

Next, in S205, it is monitored that the fed paper reaches the paper feed sensor 12. If the paper feed sensor is not "L", it waits until it becomes "L",
When it becomes "L" (T2), the fixing temperature control for starting the fixing device 13 to a temperature sufficient to start the printing operation in S206 is started.

Next, in S207, it is monitored that the fed paper reaches the registration sensor 17. If the registration sensor 17 is not "L", the process waits until the registration sensor 17 becomes "L". When the registration sensor 17 becomes "L", the print start signal is monitored in S208. If the print start signal is not "L",
The process proceeds to S209, where the registration roller 11 is turned off, and if it is within a predetermined time in S213 described later, the process proceeds to S208 (T3). If the print start signal is "L",
The process proceeds to S210, where the registration roller 11 is turned on,
The process moves to S211.

In S211, the arrival of the sheet at the top sensor 16 is monitored, and the top sensor 16 is set to "L" (T
After 5), a sub-scanning synchronization signal is sent to the control unit 25 after a predetermined time, and the printing operation starts (T4). Thereafter, after the printing operation is completed, the process proceeds to S201 (T6).

If the print start signal is "L" in S202, the cassette paper 9 is fed by the paper feed roller 10 in S212, and the driving of the polygon motor in the optical unit 3 is started. Pre-processing to enter,
And the temperature control is started. Then, the process proceeds to S211.

In S213, the time when the print start signal becomes "L" is monitored. If the print start signal does not become "L" after the lapse of a predetermined time ta or more, the flow shifts to S201 (T1).

In the above embodiment, S2 in FIG.
It is also possible to start the fixing unit temperature control at 05 by detecting a sheet by the paper feed sensor 12 and then starting a timer in the CPU and starting the fixing unit temperature control after a predetermined time. The predetermined time can be stored in advance in a program in the ROM or can be realized by an external input, for example, information on a variable resistor or a video interface.

[0036]

According to the present invention, a first print printer is provided.
And reduce the overall time to the fuser.
Electricity time can be reduced as much as possible,
It is possible to reduce consumption and extend the life of the fuser.
It has the effect of cutting.

[0037]

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a configuration of a video controller in the embodiment.

FIG. 3 is a sectional view showing a structure of a printer engine unit in the embodiment.

FIG. 4 is a flowchart showing the operation of the video controller of the embodiment.

FIG. 5 is a flowchart showing an operation of the printer engine unit of the embodiment.

FIG. 6 is a timing chart showing the timing of the printing operation of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Printer body, 2 ... Photoreceptor drum, 5 ... Charging device, 6 ... Developing device, 7 ... Transfer device, 10 ... Feeding roller, 11 ... Registration roller, 12 ... Feeding sensor, 13 ... Fixing device, 14 ... Paper ejection sensor, 16: top sensor, 17: registration sensor, 25: engine control unit, 40: video controller, 50: printer engine unit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 2/44 G06K 15/22

Claims (6)

(57) [Claims] 1. Code data is transmitted from a host computer.
Receiving means for receiving; developing means for developing the code data received by the receiving means into video data; paper feeding means for feeding paper; and the paper feeding means based on the video data output by the developing means Forming means for forming a toner image on the paper fed by the printer; fixing means for fixing the toner image formed by the forming means on the paper; and developing means after the receiving means receives the code data. Before the one-page expansion process by
In addition, a predetermined tie before energization to the fixing unit is started.
In timing, the predetermined signal generating means for generating a predetermined signal; in synchronism with the predetermined signal said predetermined signal generating means generates, to start the paper feed operation for forming an image of said one page An image forming apparatus comprising: a sheet feeding control unit that controls the sheet feeding unit to start feeding a sheet after the sheet feeding unit starts feeding a sheet; . 2. The fixing device according to claim 1, further comprising detecting means for detecting the fed paper, wherein the power supply control means controls the power supply to the fixing means in synchronization with the detection means detecting the paper. An image forming apparatus which controls so as to start energization. 3. The polygon mirror according to claim 1, further comprising: a polygon mirror that scans a light beam; a motor that rotationally drives the polygon mirror; and a motor that rotationally drives the motor based on the predetermined signal generated by the predetermined signal generating means. And an image forming apparatus. 4. The photoconductor according to claim 1, wherein the photoconductor carries a toner image; charging means for uniformly charging the surface of the photoconductor; and a predetermined signal generated by the predetermined signal generating means. Means for controlling the charging means to perform pretreatment. An image forming apparatus comprising: 5. The image forming apparatus according to claim 1, further comprising means for controlling to stop the process control when a print start signal is not received by a predetermined time. 6. Code data is transmitted from a host computer.
A receiving step for receiving; a developing step for developing the code data received in the receiving step into video data; and a developing step for one page after receiving the code data.
Before power-up ends and power supply to the fuser starts.
At a predetermined timing before the predetermined signal generating step and for generating a predetermined signal; in synchronism with said predetermined signal generating the predetermined signal generated in step, in order to form an image of the one page A paper feed control step for controlling the paper feed operation to start; and feeding to the fixing device after the paper feed is started by the paper feed control step .
And a power supply control step of controlling power supply to start the power supply of the image forming apparatus.