JPS58136074A - Image formation device - Google Patents

Abstract

PURPOSE:To eliminate a blur and a stain even in case of an impact of a driving system to improve reliability by inhibiting the starting of next copying until transfer paper in successive copying mode passes through a pressure fixation roll. CONSTITUTION:For the 2nd or succeeding copy in successive copying mode, a copy inhibiting timer T based on a read end detection and set by a detection switch in the precedent copying cycle judges to a wait state wherein the starting of next copying operation is inhibited until the completion of the timer T . In this wait state, transfer paper is conveyed out of the pressure fixation roll, so an impact to the driving system is allowed to occur while copying operation is not carried out to eliminate an influence upon the quality of the copy.

Description

[Detailed description of the invention] The present invention relates to an image forming apparatus such as a copying machine.

Conventionally, in a copying machine having a fixing device, the fixing device a
When the transfer paper carrying the toner image is transferred to a, especially at the end of the transfer paper from the pressure fixing device n, the return of a pair of p-ra to which a predetermined EE force is applied in the pressure fixing device is performed. Because of this, a shock may be generated, and this has a large effect on the device. In other words, the drive system is the original scanning system,
If the thread is common to at least one of the photoreceptor drive system and the transfer paper conveyance system, the VN strike was a normal copying process.

A similar problem also occurs when the transfer device includes a roller or the like whose drive is controlled by VJ.

In order to eliminate the above-mentioned drawbacks, the present invention has a structure in which the fixing device is configured to prohibit the next copying operation until the transfer paper is ejected, so that the impact of the drive system by the fixing device does not occur during the copying operation. This can prevent deterioration in image quality.

Further, the present invention is configured to delay the start of the repeating cycle of image formation by a predetermined period of time only in the image forming operation of a specific size.
Since the formation of the next image can be prevented while the sheet is passing through the transfer device, the image quality of the sheet being passed through and the image quality of the next cycle can be maintained well.

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

FIG. 1 is a schematic configuration diagram of a copying machine in this embodiment.

In the figure, 1 is the main body of the copying machine, 2 is a document platen on which a document is placed at IF 2 and moves back and forth, 3 is a rotatable drum having a photoreceptor around it, 26 is a drive motor for a drive system to be described later, 24
2 is a forward and rear clutch that controls the reciprocating movement of the document table;
0 is a lamp for exposing the original image onto the drum 6; 19 is a developing roller for developing the electrostatic latent image; 16 is a transfer charger for transferring the developed image onto transfer paper 14; and 15 is for charging the photoreceptor surface. A charger 16 is a voltage remover for removing residual charges on the drum 6, 12 is a separating mechanism for separating the transfer paper 14 from the drum 5, and 11 is a cassette storing a large number of transfer papers 14, which can be attached to and detached from the main body 1. It consists of: 6 is a paper feed roller that feeds the transfer paper 14 from the cassette 11, 4 is a pressure fixing roller, and 5 is a timing sw when the document platen 2 moves forward.
21 is a standby roller that starts rotating; 17 is a lens for forming an image of the light reflected from the document by the exposure lamp 20 on the drum surface; and 22 is a fixed position switch that determines whether the document table 2 is in the fixed position or not. , 10 is a detection switch for detecting the transfer paper 14, and constitutes size detection and jam detection means. 7 is an operation panel, 8 is a copy start switch for starting copying, and 9 is a paper jam indicator.

Figure 2 i, J? , 9; is a block diagram showing a control unit of Meiso. In the figure, μOOM is a well-known one-chip microcomputer, such as the μPD546 manufactured by NEC Corporation. NT is an interrupt date, which generates a clock in response to the rotation of the drum. Apo Tsul
The pulse f from the generator 25 is waveform-shaped by a No. 1 capacitor and inputted to C. 45-1゜45-2 is a transistor for amplification, Tr is an amplification transistor, a display device for displaying the number of 10th and 1st copies. 45-.1.45-2 is for segment selection via driver 8D.
-, and dynamically displays the A1 information based on the digit selection signal from the output dates R4 and Rs. 9.
48 and 49 are indicators that light up when a paper jam or no toner is detected, respectively, and the output N-tl'(a
~ Controlled by the output signal from the island. copy button,
Stop l button, ten and one for setting the number of copies, clear key, etc. are output capo) Hours and minutes from K8o-KSs! #I
Scanned by the I signal, the state of the key changes from 0 to
input cassette dynamically.

In addition, the input &-) Po-P has a detection switch 1 [ ] and a timing switch 21 . Signal S from fixed position switch 22
l, S, are input. Also, the output d'-)F.

From ~F, input 1 to the microcomputer μCOM
Based on No. M, a drive signal is sent to the drive motor 23 through the drivers D1 to D, respectively, a document platen forward clutch drive signal for the reciprocating clap 24, a backward latch drive signal for the reciprocating 2-piece 24, and a paper feed row 26. A drive signal for the timing roller 5, a lighting signal for the exposure 2 lamp 20, a drive signal for the developing roller 7, and a drive signal for the high voltage transformer 27 are output.

The drive motor 25 in FIG. 1 is a photosensitive drum λ'5. Forward and backward movement 2 for moving the document table 2 forward and rearward 24. Developing roller 171M Paper roller 6, standby (lens)) 0-1
5. Separation mechanism 12. This is the drive source for the drive system of the pressure fixing row 24, and the ties rTφ to T6, which will be described later, are connected to each other by an unillustrated dean, a timing belt, etc. It has been set.

The microcomputer μOOM Gl has a ROM containing a program shown in the flowchart of FIG. 6, processes input signals according to the procedure, and performs output operations as shown in FIG. 4.

The photographing operation and the operation of the detection function in this embodiment will be explained using the flowchart of FIG. 6 and the time chart of FIG. 4. When the continuous copy mode is currently set, when the copy start switch 8 is pressed while a copy operation is possible, the drive motor 25, transfer charger 13, and static eliminator 16 are turned on (atepl). At this time, the normal position switch 22 determines whether or not the document table 2 is in the normal position. If it is determined that the document table 2 is not in the normal position, the reverse clutch 24 is turned on, and the normal position switch 22 detects the document table 2. Move the original platen 2 in the direction of the home position until (stop 2)
)) At the same time as the fixed position switch 22 detects the original platen 2, it turns off the two backward movement levers. In the next step 5, top 3, the copy prohibition timer T of this embodiment is checked, but this will be described later as it relates to the second and subsequent copies of the number of copies in the continuous copy mode. Since the copying cycle for the first sheet is currently in progress, the copy prohibition timer has been reset. Next, the paper feed roller 6 is turned on by operating the on-time timer T of the paper feed row 26. Furthermore, a timer T that determines the timing to turn on the forward clamp 24 is operated, the exposure lamp 20 is turned on, and the charger 15 is turned on (atep 4). Thereafter, wait for the timer T11 to end, and at the same time, turn on the forward 2 lever 24, advance the document table 2, and set the timer T11 to determine the on time of the clutch 24.
, is operated (step 5). After that, wait for the timer T1 to end, and at the same time turn off the paper feed roller 6 and turn on the developing roller (stop 6) 0 At this time, the transfer paper 14 is fed from the cassette 11 and reaches the position where it reaches the standby roller 5. It is in a stopped state. When the tie switch 21 is turned on due to the advance of the document table 2, the rotation of the standby roller 5 is started, and the feeding of the transfer paper 14 is restarted. At the same time, timer T4 is activated. Timer T4 is the detection switch 10
is a timer that determines the timing to start detecting the transfer paper 14 (stop?). If the transfer paper 14 is being fed normally when the timer T4 expires, the detection switch 10 should have detected transfer and IE 14 and turned on. However, if the detection switch 10 does not detect the transfer paper 14 even after the timer T4 ends, the transfer paper 14 is not detected in the cassette 1.
The transfer paper 14 is judged to have stagnated before reaching the detection switch 10 and stopped the full load output as a JAM process. Then, the JAM display is turned on and the operation is stopped (gtep8). If the transfer paper 14 is detected normally, wait for the forward 2 timer timer T to finish, and then start the timer T.

When this is completed, turn off the forward clutch and turn on the reverse clutch. At the same time, exposure lamp 20. Turn off the charger 15. At that point, a check is made to see if the detection switch 10 is detecting the transfer paper 14, and if the detection switch 10 is on, the timer cassette count of the copy prohibition timer Tφ is started, and the detection switch 10 detects the transfer paper 14. The copy prohibition timer T continues until the paper 14 is no longer detected, that is, until the rear end of the transfer paper 14 crosses the detection switch 10.
Continue counting the timer cassette of φ. When the rear end of the transfer paper 14 pulls out the detection switch 10, the detection switch 10 is turned off, and the timer set value of the copy prohibition timer Tφ is stored in the RAM of the microphone 4 computer and moOM (not shown in the figure). Then, the developing roller 9 and the standby roller 5 are turned off (stoplo).

Next, the home position switch 22 is checked until the document table 2 returns to the home position, and when it returns to the home position, the home position switch 22 is turned on and the two backward movement switches are turned off (at
epH).

Next, it is determined whether the mode is continuous copy mode, and if it is continuous copy mode, the copy operation is started again from atep3 (atepl2).

In this way, in atep3 for the second and subsequent copies in the continuous copy mode, the copy prohibition timer Tφ is determined by detecting the trailing edge of the transfer paper 14 set by the detection switch 10 during the previous copy cycle, and if the timer T
If φ is set, a wait state is entered in which the start of the next copying operation is prohibited during the end Tt of the 114-minute tie. During this wait state, the transfer paper 1 shown in FIG.
4 carries out the pressure fixing roller 4, the above-mentioned impact on the drive system should be made to occur during the period when no copying operation is being performed, so as not to affect the copy quality in any way. It makes it possible. At the end of the copy mW M timer Tφ, the process proceeds to the next step 4 and subsequent steps, and the steps are deviated along the copy cycle described above.

In the final copy cycle of continuous copying, i+tap12
, set the rear 1u turn timer T, and set the timer T.
Waiting for the completion of , the drive motor 25, transfer 16, static elimination 1
6 is turned off, the copy prohibition timer Tφ is reset, and the copying operation is completed.

Each timer operation is achieved by counting the pulses from the clock pulse generator ag#25 input to P(EOM) for each timer. show.

As described above, according to the present invention, by prohibiting the start of copying in the next copying mode until the transfer paper in the continuous copying mode pulls out the pressure fixing roll, the copying quality can be improved even if a shock occurs in the drive system. Without affecting the carving? The simple configuration makes it possible to increase reliability.

Incidentally, even when driving means are used for the transfer means 12 and the separation means 15, the same pressure can be applied to prevent inconveniences caused by driving impact. It is also possible that the size signal generation means generates a size RS by inserting a cassette or a key size signal by an operator.

[Brief Description of the Drawings] Fig. 1 is a schematic configuration diagram of the copying machine in this embodiment, Fig. 2 is a control circuit diagram of the copying machine in this embodiment, Fig. 3 is a flow chart diagram in this embodiment, and Fig. 4 is a schematic diagram of the copying machine in this embodiment. The figure is a time chart diagram in this embodiment, and in the figure, 4 indicates fixation"?, 2
5 is a main drive motor, and 10 is a transfer paper detection switch. Applicant: Canon Co., Ltd.

Claims (3)

[Claims] (1) A grossing means that forms an image on the conveyance system, a member that is installed on the conveyance path of the conveyed material to process the first conveyed paulownia (a member whose drive is controlled), and a grossing means that forms an image on the conveyance system, and a and means for inhibiting imaging cycle operation. (2) The image forming apparatus according to item 1, wherein the processing member is a means for fixing the image on the conveyance material under pressure. (3) Images that are similar in that the next image forming cycle is started in response to the passage of the conveyed material in item 1.