JP2000278884A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make easier such a recovery process as the removal of jammed paper, the toner left on a developing roll, etc., performed on an image forming device after the device returns to a normal state, by operating prescribed parts in the device for a prescribed period of time when a normally used power source is emergently turned off due to an abnormal status during the image forming operation of the device. SOLUTION: The image forming device U is constituted of an emergency power source 1 which is used instead of a normally used power source when an abnormal status occurs during the image forming operation of the device U, and an emergency control means C1 which operates predetermined parts 26c for a prescribed period of time by using the power supply from the power source 1.

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 such as an electrophotographic copying machine or a laser printer, and more particularly to an image forming apparatus provided with an emergency off power supply for driving a predetermined apparatus for a predetermined time during an emergency off such as a power failure. About.

[0002]

2. Description of the Related Art In the above-mentioned image forming apparatus, all the functions of the apparatus are instantaneously stopped at the time of a power failure or an electric emergency off such as disconnection of a power supply plug from an outlet during operation. Is common.

At this time, for example, the following problems (a) to (c) occur inside the image forming apparatus.
Occurs. (A) In a purge type image forming apparatus in which two developing units are vertically arranged in two tandem with respect to each image carrier as disclosed in Japanese Patent Application Laid-Open No. Hei 4-204871, FIG. 14 is a time chart showing an example of an operation at the time of normal stop and an operation at the time of emergency off in the conventional purge type developing device, FIG. 14A is a time chart at the time of normal stop,
FIG. 14B is a time chart at the time of emergency off. FIG.
In each of the developing devices operating according to the time chart shown in FIG. 5, the developer transport roller is driven by a developing device motor via a developing roller and a clutch. The developer transport roll supplies a developer to the developing roll.

In FIG. 14A, in a normal case, when the developing operation is completed, the clutch is turned off at a time TMa, and the driving of the developer conveying roll is stopped. The motor for the developing device is driven until time TMb, during which time the developer transport roll stops rotating and rotates the developing roll. The developer is not supplied by the developer transporting roll, the developer on the developing roll is collected into the developing device, and the developer on the developing roll is removed (purged). At time TMc, the main power supply is turned off. However, in FIG. 14B, at time TMd during the developing operation, when a power failure occurs and the main power supply is turned off, the developing roll stops rotating and the developer on the developing roll is not purged, and the developing roll and the developing roll are not purged. The state in which the developer remains between the image carrier and the image carrier is obtained. When such a state occurs in the lower developing device, after the return, when the upper developing device starts the developing operation at the start of the next job, the image on the image carrier developed by the upper developing device is started. There is a problem that the toner image mixes with the residual toner on the developing roll of the lower developing device at the position of the lower developing device on the downstream side in the moving direction. For this reason, it is necessary to remove the residual toner on the developing roll of the lower developing unit at the time of return, and in that case, the toner is wasted. Further, during an operation such as removal of a jammed recording sheet in the apparatus due to an emergency off, the residual toner on the developing roll of the developing unit may adhere to an operator's hand or the like.

[0004] (b) When the emergency off occurs during fixing: In such a case, the paper being fixed is sandwiched between the heating roll and the pressure roll in the fixing device and the jam cannot be removed. Become. In this case, it sometimes causes a fire or takes time to take out the paper after returning. (C) When the emergency off occurs when the sheet is taken out of the sheet storage tray that stores the sheet by the sheet conveyance device and is conveyed: In such a case, if the sheet is stopped at a position where the sheet is difficult to be taken out, after returning, There is a problem that it takes time to take out the paper.

In view of the above circumstances, the present invention provides the following (O01)
Is the subject of the description. (O01) By operating a predetermined component in the image forming apparatus for a predetermined time when an emergency power supply (normally used power supply) is turned off due to occurrence of an abnormal situation during an image forming operation of the image forming apparatus,
To facilitate recovery processing such as paper jam processing after recovery and removal of residual toner on the developing roll.

[0006]

Next, the present invention devised to solve the above-mentioned problems will be described. Elements of the present invention are used to facilitate correspondence with elements of the embodiments described later. , The reference numerals of the elements of the embodiment are enclosed in parentheses. The reason why the present invention is described in correspondence with the reference numerals of the embodiments described below is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

(Invention) In order to solve the above problems, the image forming apparatus of the invention has the following requirements (A01) and (A02)
It is characterized by having. (A01) Emergency power supply (1) used in place of the normal power supply when the power supply normally used (normal power supply) is turned off due to the occurrence of an abnormal situation during the image forming operation of the image forming apparatus (U) (A02) The emergency power supply (1)
(26c, 26k; 6; Rk)
Emergency operation means (C1, C3, C4) for automatically operating and stopping for a predetermined time.

(Operation of the Present Invention) In the image forming apparatus of the present invention having the above configuration, the emergency power supply (1) is normally used due to occurrence of an abnormal situation during the image forming operation of the image forming apparatus (U). It is used in place of the normal use power supply when the power supply (normal use power supply) is turned off in an emergency. At the time of the emergency OFF, the emergency control means (C1, C3, C4) performs predetermined parts (26c, 26c) predetermined by the emergency power supply (1).
k; 6; Rk) are automatically operated for a predetermined time and then stopped. Therefore, when a problem occurs when the power supply is stopped in the emergency off state of the normal use power supply (for example, when the jam sheet removal operation is not easy), a problem-free state (for example, when the jam sheet removal is easy). )
And then stop.

[0009]

(Embodiment 1) Embodiment 1 of the image forming apparatus of the present invention is characterized in that the present invention satisfies the following requirement (A03). (A03) The predetermined components (26c, 26
k; 6; the emergency power supply (1) connected to the power supply wires (La, Lb) to Rk). (Effect of First Embodiment) In the first embodiment of the image forming apparatus of the present invention having the above-described configuration, the emergency power supply (1)
Means that the predetermined components (26c, 26k;
6; Rk) are connected to power supply conductors (La, Lb).
In this case, when the normal use power supply is turned off urgently, the emergency use power supply (1) can supply power to the predetermined components (26c, 26k; 6; Rk) from the power supply conductors (La, Lb).

(Embodiment 2) Embodiment 2 of the image forming apparatus of the present invention is characterized in that the following requirement (A04) is provided in the present invention or Embodiment 1. (A04) The predetermined parts (26c, 26
k; 6; Rk), the emergency power supply (1) which is constituted by a rechargeable battery connected to the power supply conductors (La, Lb). (Effect of Second Embodiment) In the second embodiment of the image forming apparatus of the present invention having the above configuration, the emergency power supply (1)
Means that the predetermined components (26c, 26k;
6; a rechargeable battery connected to the power supply wires (La, Lb) to Rk). In this case, when power is supplied from the normal power supply to the predetermined components (26c, 26k; 6; Rk), the emergency power supply (1) is charged. Therefore, when the normal power supply is turned off in an emergency, the charged emergency power supply (1) is connected to the power supply lead (L).
a, Lb) to the predetermined part (26c, 26k; 6; Rk)
Can be fed to

(Embodiment 3) An embodiment 3 of the image forming apparatus of the present invention is characterized in that the following requirement (A05) is provided in the present invention or Embodiment 1. (A05) The emergency power supply constituted by a power storage unit connected to a power supply lead (La, Lb) from the normal power supply to the predetermined component via an on / off switch (SW) which is automatically turned on at the time of the emergency off. When using power supply (1). (Effect of Third Embodiment) In the third embodiment of the image forming apparatus of the present invention having the above-described configuration, the emergency power supply (1) including a battery is automatically turned on at the time of the emergency off. Power supply wires (La, Lb) from the normal power supply to the predetermined component via an on / off switch (SW).
It is connected to the. Therefore, at the time of emergency off, the emergency use power supply (1) is connected to the on / off switch (SW).
, Power can be automatically supplied to the predetermined component.

(Embodiment 4) An image forming apparatus according to Embodiment 4 of the present invention is characterized in that the following requirements (A06) to (A010) are provided in the present invention or Embodiment 1 or 3. I do. (A06) An image carrier (PR1, PR2) in which electrostatic latent images corresponding to images of different colors are sequentially written on a rotating surface by a latent image writing device (ROS1, ROS2). (A07) The image carrier. A first fixedly disposed around the image carrier (PR1, PR2) facing the body surface;
A plurality of developing units (Gy, Gm, Gc, Gk) including a developing unit (Gy, Gm) and a second developing unit (Gc, Gk), wherein an electrostatic latent of a color written on the surface of the image bearing member is provided. A plurality of developing units (Gy, Gm, Gc, Gk) for developing the electrostatic latent image into a toner image with a developer of a color corresponding to the image; (A08) disposed adjacent to the surface of the image carrier; A developing roll (26y, 26m, 26c, 26k), a non-magnetic sleeve rotatably disposed adjacent to the developing roll (26y, 26m, 26c, 26k), and a magnetic force generating member disposed inside the sleeve The developer adhered to the surface of the sleeve when the sleeve is rotated.
A plurality of developing units (Gy, Gm, Gc, Gk) each having a developer transport roll (25y, 25m, 25c, 25k) for supplying to the developing units 6y, 26m, 26c, 26k); When the developing operation of the developing device (Gy, Gm, Gc, Gk) which has performed the developing operation of the developing devices (Gy, Gm, Gc, Gk) is completed, the developer transport rolls (25y, 25
m, 25c, 25k) with the developing roll (26
y, 26m, 26c, and 26k) are rotated for a predetermined period of time, so that the developer on the developing roll surface is adsorbed on the developer transport rolls (25y, 25m, 25c, and 25k) and purged from the developing roll surface. Developer purging operation executing means (C2) for executing an agent purging operation; (A010) the predetermined component is a developing roll (26)
c, 26k), the emergency control means (C1) having an emergency purge operation executing means (C1a) for executing the developer purge operation by the emergency power supply (1) for the predetermined time during the emergency off. .

(Effect of Embodiment 4) In Embodiment 4 of the image forming apparatus of the present invention having the above-described configuration, the image carriers (PR1, PR2) are provided with latent image writing devices (ROS1, ROS).
2) The electrostatic latent images corresponding to the images of different colors are sequentially written on the rotating surface. A plurality of developing devices (G) including a first developing device (Gy, Gm) and a second developing device (Gc, Gk).
y, Gm, Gc, Gk) are arranged opposite to the surface of the image carrier and fixed around the image carriers (PR1, PR2), and the static colors of the colors written on the surface of the image carrier are provided. The electrostatic latent image is developed into a toner image with a developer of a color corresponding to the electrostatic latent image.

The plurality of developing units (Gy, Gm, Gc, G
k) is a developing roll (26y, 26m, 26c, 26k) disposed adjacent to the surface of the image carrier, and is rotatably disposed adjacent to the developing roll (26y, 26m, 26c, 26k). A non-magnetic sleeve and a magnetic force generating member disposed inside the sleeve. The developer transport roll (2) of each of the plurality of developing units (Gy, Gm, Gc, Gk)
5y, 25m, 25c, and 25k) are used to transfer the developer adhered to the surface of the sleeve when the sleeve rotates to the developing roll (2).
6y, 26m, 26c, 26k). The developer purging operation executing means (C2) includes a plurality of the developing devices (Gy, Gy).
m, Gc, Gk) that have performed the developing operation (Gy,
By rotating the developing rolls (26y, 26m, 26c, 26k) for a predetermined period with the developer transporting rolls (25y, 25m, 25c, 25k) stopped at the end of the developing operation of Gm, Gc, Gk), Developing roll (26y, 26
m, 26c, 26k) is adsorbed on the developer transport rolls (25y, 25m, 25c, 25k) and purged from the surface of the developer rolls (26y, 26m, 26c, 26k).

When the emergency is turned off, the emergency control means (C
The emergency purging operation executing means (C1a) executes the developer purging operation by the emergency power supply (1) for the predetermined time. Therefore, when the printer is returned after the emergency off, since the developer is not attached on the developing rolls (26c, 26k), the recording sheet (S) jammed by the emergency off is removed. During the operation, the developing device (G
The toner remaining on the developing rolls (c, Gk) (26c, 26k) does not adhere to the operator's hands and the like, and the recovery process can be facilitated.

(Embodiment 5) Embodiment 5 of the image forming apparatus of the present invention is characterized in that the following requirements (A011) to (A013) are provided in the present invention or Embodiment 1 or 3. I do. (A011) A recording sheet (S) having a pair of fixing rolls (Fp, Fh) and passing through a fixing area (Q5) formed by a pressure contact area of the pair of fixing rolls (Fp, Fh) pressed against each other. A fixing device (F) for fixing the upper toner image; and (A012) a fixing roll press-contact / separation device for moving the pair of fixing rolls (Fp, Fh) between a press-contact position where they press against each other and a separation position where they are separated. (A013) The predetermined component (6, 6) is the fixing roll press-contact / separation driving member (6, 6), and the predetermined time is the pair of fixing rolls. (Fp, Fh) is the time required to move from the pressure contact position to the separation position, and when the emergency is off, the fixing roll pressure contact / separation drive member (6, 6) is supplied by the emergency power supply (1). ) For the above-mentioned predetermined time, the emergency fixing roll pressure welding The emergency control means having a separation driving member control means (C3a) (C
3).

(Effect of Embodiment 5) In Embodiment 5 of the image forming apparatus of the present invention having the above configuration, the fixing device (F) has a pair of fixing rolls (Fp, Fh), The toner image is fixed on the recording sheet (S) passing through a fixing area (Q5) formed by the pressure contact area of the pair of fixing rolls (Fp, Fh). The driving member (6, 6) for fixing roll press-contact / separation is connected to the pair of fixing rolls (F
p, Fh) are moved between a press-contact position where they press against each other and a separated position that is separated. At the time of the emergency-off, the emergency fixing roll press-contact / separation drive member control means (C3a) of the emergency control means (C3) is adapted to control the predetermined components (6, 6) by the emergency power supply (1). Is driven for the predetermined time, that is, the time required for the pair of fixing rolls (Fp, Fh) to move from the pressure contact position to the separation position. For this reason, even if the recording sheet (S) is turned off urgently while passing through the fixing area (Q5), and the recording sheet (S) stops moving within the fixing area (Q5), the recording sheet (S) does not move. Is easy to take out.

(Embodiment 6) Embodiment 6 of the image forming apparatus of the present invention is characterized in that the following requirements (A014) to (A016) are provided in the present invention or Embodiment 1 or 3. I do. (A014) Pickup roll (R) for taking out recording sheets (S) stored in paper feed trays (TR1, TR2)
p), a paper feed roll (Rk) for feeding the taken out recording sheet (S) to the sheet conveyance path (SH1), and conveying the recording sheet (S) fed to the sheet conveyance path (SH1). Sheet transport device having transport roll (Ra) (S
H), (A015) A sheet position sensor (SN) for detecting whether or not the recording sheet (S) fed by the paper feed roll (Rk) is conveyed to a position where it can be easily removed at the time of the emergency off.
2), (A016) the predetermined component (Rk) is a paper feed roll (Rk), and the predetermined time is the paper feed roll (Rk).
The time required for the recording sheet (S) fed from the emergency off position to move to the easy-to-remove position from the emergency-off position.
The emergency control means (C4) having an emergency paper feed roll drive control means (C4a) for rotating the paper feed roll (Rk) for the predetermined time.

(Operation of Embodiment 6) In Embodiment 6 of the image forming apparatus of the present invention having the above-described configuration, the sheet conveying device (SH) includes a pickup roll (Rp), a paper feed roll (Rk), It has a transport roll (Ra), and the pickup roll (Rp) has a paper feed tray (TR1, TR1).
Take out the recording sheet (S) stored in 2). The paper feed roll (Rk) feeds the taken out recording sheet (S) to the sheet transport path (SH1). The transport roll (Ra) transports the paper fed to the sheet transport path (SH1). At the time of the emergency OFF, the emergency paper feed roll drive control means (C4a) of the emergency control means (C4)
The paper supply roll (Rk), which is the predetermined component (Rk) determined by the emergency power supply (1), is supplied for a predetermined time, that is, the recording sheet (Rk) fed by the paper supply roll (Rk). S) is rotationally driven for a period of time from when the emergency OFF position is moved to the position where the removal is easy. The sheet position sensor (SN2) detects whether or not the recording sheet (S) fed by the paper feed roll (Rk) is conveyed to a position where it can be easily removed during the emergency off. Therefore, it is easy to remove the recording sheet (S) that has stopped moving during conveyance due to emergency off.

(Examples) Next, specific examples (examples) of embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following examples. (Embodiment 1) FIG. 1 is an explanatory view of Embodiment 1 of a color image forming apparatus having a sheet conveying belt in contact with a plurality of image carriers. FIG. 2 is an enlarged view of a main part of FIG.

In FIG. 1, an image forming apparatus U includes a main body Ua.
And an automatic document feeder Ub placed on a platen glass PG on the upper surface of the main body Ua. The image forming apparatus main body Ua has a UI (user interface) for a user to input an operation command signal such as copy start.

In the ADF mode in which copying is performed using the automatic document feeder (auto document feeder) Ub, the exposing optical system A is stopped at the home position, and the copying position on the platen glass PG is sequentially changed. Each passing document Gi is exposed. In the platen mode in which the operator places a copy of the original Gi on the platen glass PG, the exposure optical system A exposes and scans the original on the platen glass PG while moving.

The reflected light from the original document Gi is transmitted through an exposure optical system A to a CCD (solid-state image pickup device) driven by a CCD drive circuit (see FIG. 3).
(Blue) electrical signal. The IPS (image processing system) uses the R input from the CCD.
The GB electric signals are represented by Y (yellow), C (cyan), M
The image data is converted into (magenta) and K (black) image data, temporarily stored, and output to the laser drive circuit DL as latent image forming image data at a predetermined timing. If the original image is monochrome, only K (black) image data is input to the laser drive circuit DL.

The laser drive signal output device DL has laser drive signal output circuits DL1 and DL2 for the respective colors Y, C and M, K. Each of the laser drive signal output circuits DL1,
DL2 outputs a laser drive signal corresponding to the input image data at a predetermined timing to each of the latent image writing devices ROS1 and RO.
Output to S2.

After the respective image carriers PR1 and PR2 are uniformly charged by the respective charging corotrons Cc1 and Cc2, the latent image writing device ROS in the image writing areas Q11 and Q12.
1. An electrostatic latent image is formed on the surface by the laser beams L1 and L2 output from ROS2. The image carrier PR1, P
The electrostatic latent images on the R2 surface are developed areas Q2y, Q2c, Q2m, Q2
At k, the toner images are developed by the developing units Gy, Gc, Gm, Gk. The developing units Gy and Gc are provided on the image carrier P
The first developing device Gy and the second developing device Gc for R1 and the developing devices Gm and Gk are the first developing device Gm and the second developing device Gk for the image carrier PR2. The developed color toner image is conveyed to transfer areas Q31 and Q32 that come into contact with the sheet conveying belt B. In the case of only black image data, only the image carrier PR2 for K (black) and the developing device Gk are used, and only a black toner image is formed.

Below the image carriers PR1, PR2, a movable table F1 is supported by a pair of left and right movable table slide rails SR, SR so as to be slidable back and forth (in a direction perpendicular to the paper surface). A belt module (vertical moving member) F2 is supported on the movable table F1 so as to be able to move up and down. The belt module F2 includes the sheet transport belt B, a belt driving roll Rd, a tension roll Rt, a walking roll Rw, and a belt supporting roll (Rd, Rt, Rw, Rf) including an idler roll (free roll) Rf. It has rolls T1 and T2. The sheet conveying belt B is connected to the belt supporting rolls (Rd, Rt, Rw, R
It is rotatably supported by f).

FIG. 1 shows a state in which the belt module F2 is held at a raised position (a position where the sheet conveying belt B contacts the lower surface of the image carriers PR1 and PR2). When it is moved back and forth in order to be attached to or detached from the main body Ua, it is held at a lowered position (a position where the sheet conveying belt B is separated downward from the image carriers PR1 and PR2). Therefore, when the moving table F1 and the belt module F2 supported by the moving table F1 are attached to and detached from the image forming apparatus main body, the belt module F2 is configured not to make frictional contact with the image carriers PR1 and PR2. ing. Such a configuration for moving the movable table F1 back and forth and a configuration for raising and lowering the belt module F2 are conventionally known (see, for example, JP-A-8-171248), and various conventionally known configurations may be employed. It is possible.

The paper S on the paper feed tray TR1 disposed below the sheet transport belt B is taken out by a pickup roll Rp, separated one by one by a paper feed roll Rk, and then sent to a registration roll Rr. The registration roll Rr conveys the sheet S to the sheet suction position Q4 at a predetermined timing. A suction roll Rb is arranged at the sheet suction position Q4, and electrostatically suctions the sheet S to the sheet transport belt B. The sheet S adsorbed on the sheet conveying belt B sequentially passes through the transfer areas Q31 and Q32 that are in contact with the image carriers PR1 and PR2.

In the transfer areas Q31 and Q32, the transfer rolls T1 and T2 disposed on the back side of the sheet conveying belt B are supplied with a polarity opposite to the charge polarity of the toner at a predetermined timing from a power supply circuit E controlled by the controller C. Is applied. In the case of a color image, the first developing units Gy and Gm form the sheet S on the image carriers PR1 and PR2 when the sheet S is first attracted to the sheet transport belt B and passes through the transfer areas Q31 and Q32. The Y and M toner images are transferred onto the sheet S by the transfer rolls T1 and T2. During this time, the second developing devices Gc and Gk do not perform the developing operation. Next, when the sheet S makes one rotation with the sheet conveying belt B and passes through the transfer areas Q31 and Q32 again, the second
The C and K toner images formed on the image carriers PR1 and PR2 by the respective developing units Gc and Gk are transferred to be superimposed on the Y and M toner images on the sheet S. During that time, the first developing units Gy and Gm of the Y and M do not perform the developing operation.

In the case of a monochrome image, the image carrier PR
2, only a K (black) toner image is formed,
Only the (black) toner image is transferred to the sheet S by the transfer unit T2. The sheet S to which the toner image has been transferred is separated from the separation nail H
f, the sheet is separated from the sheet conveying belt B, and the fixing area Q5
Is fixed by the fixing device F when passing through the discharge roller R
From h, it is discharged to the discharge tray TR2.

The toner remaining on the surfaces of the image carriers PR1 and PR2 after passing through the transfer areas Q31 and Q32 is removed by the image carrier cleaner C.
It is removed by L1 and CL2. After passing through the transfer areas Q31 and Q32, the sheet conveying belt B is cleaned by a belt cleaner CL2.

In FIG. 2, since the developing units Gy and Gc have substantially the same configuration, the developing unit Gc will be described as a representative. The developing device Gc includes a developing container 21c, a pair of developer stirring and conveying members 22c and 23c housed in the developing container 21c, a paddle 24c (developer stirring member),
It has a developer transport roll 25c and a developing roll 26c. The developing roll 26c and the developer transporting roll 25c include a magnet (not shown) fixed inside and a non-magnetic sleeve. Further, a paddle 24c is provided near the developer peeling / adsorbing portion Qa of the developer transport roll 25c.

Further, the developer stirring and conveying members 22c, 23c
Is an auger, which conveys the developer in the direction of the rotation axis, the collected toner and the developer used for development,
Stirring is performed with the developer not used for forming the developer layer. A layer forming member 27c for forming a developer layer is provided near the developer transport roll 25c. The first developing device Gy has the same configuration as the second developing device Gc, and includes a developing container 21y, a pair of developer stirring and conveying members 22y and 23y housed in the developing container 21y, and a paddle. 24y (developer stirring member) and developer transport roll 25y
, A developing roll 26y, and a layer forming member 27y. The developing units Gm and Gk have the same configuration as the developing unit Gc.

FIG. 3 is a block diagram of a main part of a control portion of the image forming apparatus according to the first embodiment of the present invention. In FIG. 3, a controller C includes an I / O (input / output interface) for inputting / outputting signals to / from external devices and adjusting input / output signal levels, and a ROM storing programs and data for performing necessary processing.
(Read only memory), RAM (random access memory) for temporarily storing necessary data, CP for performing processing according to a program stored in the ROM
U (central processing unit) and a computer having a clock oscillator and the like, and the ROM
Various functions can be realized by executing the program stored in the.

The controller C has an image forming apparatus U
A signal is input from a UI (user interface) having a display unit Ia or the like on which information about the current setting state is displayed, a sensor, or other signal output elements. Further, the controller C is connected to the motor drive circuit Dc1 for the developing device Gc, the clutch operation circuit DcL, the power supply circuit E, and other control elements. The motor drive circuit Dc for the developing device Gc drives the developing roll 26c and the developer transporting roll 25c via the motor Mc for the developing device Gc. The motor Mc for the developing device Gc and the developer transport roll 25c
Are connected via a clutch CLc. The motor Mc for the developing device Gc is provided with a motor driving circuit Dc for the developing device Gc.
The driving power is supplied via the. The clutch actuating circuit DcL operates the clutch CLc, and when the clutch CLc is on and the motor Mc for the developing device Gc is driven, the developer transport roll 25c rotates. The power supply circuit E includes an AC and DC bias power supply circuit E1c for the developer transport roll 25c and a developing roll 26.
A transfer bias for developing agent and a developing bias are applied to the developer conveying roll 25c and the developing roll 26c via the AC and DC bias power supply circuit E2c for c. Further, the controller C includes a developer transport roll 2 of the first developing device Gy.
5y and a developing device Gy for driving the developing roll 26y
Motor drive circuit Dy, a developing device Gy motor My, a clutch CLy, and a clutch operating circuit (not shown) for operating the clutch CLy. The power supply circuit E
Are AC and DC bias power supply circuits E1y (see FIG. 4) for the developer transport roll 25y and AC and DC for the developer roll 26y.
A transfer bias for developing agent application and a developing bias are applied to the rolls 25y and 26y via a DC bias power supply circuit E2y (see FIG. 4).

The controller C has a function of executing a process according to an input signal from the signal output element UI or the like and outputting a control signal to each of the control elements Dc. That is, the controller C has the following functions. C1: Emergency control means The emergency control means C1 has emergency purge execution means C1a. C1a: Emergency purge execution means The emergency purge execution means C1a rotates the developing rolls 26c, 26k for a predetermined time while the developer transport rolls 25c, 25k of the second developing devices Gc, Gk are stopped during an emergency off. Accordingly, a function of causing the developer on the developing roll surface to be adsorbed by the developer transport rolls 25c and 25k and purging from the developing roll surface is provided. C2: Developer Purging Operation Executing Unit The developer purging operation executing unit C2 includes the developing units Gy to G
By rotating the developing rolls 26y to 26k for a predetermined period while the developer transport rolls 25y to 25k are stopped at the end of the developing operation of the developing devices Gy to Gk that have performed the developing operation of k, the developing roll surface A developer purging operation is performed in which the developer is adsorbed on the developer transport rolls 25y to 25k and purged from the surface of the developer roll.

(Emergency power supply)
The motor drive circuits Dc and Dy for the developing units, the clutches CLy,
An external AC power supply, which is normally used as a power supply,
5V and 24V transformed from 100V are supplied (only the controller C and the motor drive circuit Dc for the developing unit Gc are shown). 5V power supply leads La and 2 for supplying power to the controller C and the motor drive circuit Dc for the developing device Gc.
An emergency power supply 1 is connected to the 4V power supply conducting wire Lb. The emergency power supply 1 is composed of a large-capacity capacitor. The power is stored while the image forming apparatus U is in operation, and supplies power to the controller C and the motor drive circuit Dc for the developing device Gc at the time of emergency off such as a power failure. It is supposed to. At this time, electric power is also supplied from the motor drive circuit Dc for the developing device Gc to the motor Mc for the developing device Gc. Note that the K (black) developing device Gk is also used for the emergency power supply 1.
Is connected.

(Effects of the First Embodiment) In the first embodiment, a plurality of developing units Gy, Gc, G are provided for each of the image carriers PR1, PR2.
Although m and Gk face each other, the operation of the two developing units Gy and Gc facing the image carrier PR1 will be described here. FIG. 4 is a time chart of the normal operation of the Y (yellow) developing device and the C (cyan) developing device among the developing devices of the image forming apparatus according to the first embodiment of the present invention.
FIG. 5 is a time chart at the time of emergency off of the Y (yellow) developing device. FIG. 6 is a time chart when the C (cyan) developing device is in an emergency off state. 4 to 6, when the power of the image forming apparatus U is turned on, first, the image carrier PR1 is rotated by the motor for the image carrier PR1. After that, the toner adhered on each of the developing rolls 26y and 26c is removed by the image carrier P.
At the time TM0, the developing rolls 26y, 26c are rotated by the developing device motors My, Mc to transfer to the transfer roller R1, and the developing rolls 26y, 26c and the developer transporting rolls 25y, 25y,
A bias for transferring the attached developer is applied to 25c. FIG. 4-
In FIG. 6, both AC and DC are applied, but only AC or DC may be applied. Developing roll 26
After transferring the attached toner of y and 26c to the image carrier PR1,
At time TM1, the developing rolls 26y and 26c and the developer transport rolls 25y and 25c stop.

In FIG. 4, when the developing device Gy is selected at time TM2, the developing roll 26y and the developer transport roll 2 are selected.
5y rotates to supply the developer onto the developing roll 26y, and the power supply circuits E1y and E2y are turned on from time TM3 to TM4 to perform development. After the end of the developing operation, at time TM5, the rotation of the developer transport roll 25y is stopped, and the developing roll 2 is stopped.
The supply of the developer to 6y is stopped, and the developer on the developing roll 26y is purged. Thereafter, at time TM6, the rotation of the developing roll 26y is stopped. Next, the developing device Gc is selected, and the developing operation is performed. The toner attached to the developing sleeve is moved to the image carrier PR1, the developer is supplied to the developing sleeve, the developing operation is performed, and the timing of purging the developer after the developing operation is the same as in the case of the developing device Gy. is there.
When the development is completed, the developing roll 26y of the developing device Gy is
From above, the developer is in a purged state. Before the development starts, there is no developer on the developing rolls 26y and 26c of the developing units Gy and Gc facing the image carriers PR1 and PR2.

As shown in FIG. 5, during the developing operation of the Y (yellow) developing unit Gy, at time TMx, when a power failure occurs, the image carrier PR1, the developing roll 26y, and the developer carrying roll 25
The rotation of y stops, and the developer on the developing roll 26y is not purged. After the return, the residual developer on the developing roll 26y is transferred onto the image carrier PR1 by applying a bias for transferring the adhered developer to the developer transporting roll 25y.

In FIG. 6, a developing device Gc for C (cyan) is provided.
During the developing operation, when a power failure occurs at the time TMx, the rotation of the image carrier PR1 and the developer transport roll 25c is stopped. However, the developing roll 26c is rotated by the emergency power supply for Ta time to perform purging. After the return, a bias for transferring the adhered developer is applied to the developer transport roll 25c, and the residual toner on the developer roll 26c is transferred onto the image carrier PR1. At this time, since most of the toner on the developing roll 26c has been collected in the developing device Gc, there is no waste. Further, since the developer does not adhere to the developing roll 26c after the return, the residual toner on the developing roll is attached to an operator's hand or the like at the time of removing the paper S jammed due to the emergency off. The recovery process can be easily performed without putting on. Also, in the K (black) developing unit Gk, similarly to the C (cyan) developing unit Gc, purging is executed when an emergency off occurs.

(Explanation of Flowchart of Embodiment 1) FIG.
9 is a flowchart of an emergency developing roll control process of the image forming apparatus according to the first exemplary embodiment of the present invention. The processing of each ST (step) in the flowchart of FIG.
This is performed according to a program stored in the ROM. The flow of the emergency development roll control shown in FIG. 7 is started when the power is turned on. In FIG. 7, when the emergency development roll control flow is started, it is determined in step ST1 whether the copy start key is turned on. If no (N), ST1 is repeatedly executed. If yes (Y), the process moves to ST2.

In ST2, it is determined whether or not an abnormality (emergency off) has occurred. If no (N), the process moves to ST3. In ST3, it is determined whether the job has been completed. If yes (Y), the process returns to ST1, and if no (N), the process returns to ST2. In ST2,
If yes (Y), the process moves to ST4. In ST4, the fact that an abnormality has occurred is displayed on the display unit UIa. In ST5, it is determined whether or not the motor Mc for the developing device Gc is operating.
If no (N), the process moves to ST6. In ST6, it is determined whether or not the developing device Gy motor My is operating. If yes (Y), the process moves to ST7. In ST7, the developing device G
The y motor My stops. After the end of the operation of ST7, and if ST6 is NO (N), the process returns to ST1.

If yes (Y) in ST5,
That is, when the developing device Gc motor Mc is operating,
Move to ST8. In ST8, Ta (mse
Set c). In ST9, the timer TMa determines whether or not the time is up. If no (N), ST9 is repeatedly executed, and if yes (Y), the process moves to ST10.
In ST10, the motor Mc for the developing device Gc is turned off.
The process returns to ST1.

(Embodiment 2) FIG. 8 is an enlarged explanatory view of a main part of a fixing device used in an image forming apparatus according to Embodiment 2 of the present invention. In the description of the second embodiment, the first embodiment
The same reference numerals are given to constituent elements corresponding to the above-mentioned constituent elements, and detailed description thereof will be omitted. The second embodiment differs from the first embodiment in the following points, but has the same configuration as the first embodiment in other points. In FIG. 8, both ends of a heating roll Fh shaft 2 of a fixing device F used in the image forming apparatus of the second embodiment are rotatably supported by housings 3 and 3 of the fixing device F. The shaft 4 of the pressure roll Fp below the heating roll Fh is rotatably supported by the housings 3 and 3 and is also movably supported in the vertical direction. The pressure roll Fp moves in the vertical direction and presses against the heating roll Fh to form a nip (fixing area Q5), and a nip release position (separation position) where the nip is released from the heating roll Fh and released. )
It is movable between and.

Eccentric cams (driving members for fixing roll press-contact / separation) 6 and 6 come into contact with both ends of the shaft 4 of the pressure roll Fp from below, and the eccentric cams 6 and 6
3 is supported on a shaft 7 rotatably supported. A gear G0 is fixed to the outer end of the shaft 7 of the eccentric cams 6, 6, and the gear G0 meshes with a gear G1 fixed to the rotation shaft of the nip forming motor Mf.

In FIG. 8, the controller C of the second embodiment
Is input with a signal from a sensor (not shown) for detecting the sheet S in the fixing area Q5 and other signal output elements, and is connected to a nip forming motor drive circuit Df and other control elements. . The nip forming motor drive circuit Df drives the eccentric cams 6, 6 via the nip forming motor Mf. Further, the controller C of the second embodiment has the following functions. C3: Emergency control means The emergency control means C3 has an emergency fixing roll pressure contact / separation drive member control means C3a. C3a: Emergency fixing roll pressure contact / separation drive member control means Emergency fixing roll pressure contact / separation drive member control means C3a
When the sheet (recording sheet) S is detected in the fixing area Q5 at the time of the emergency off, the eccentric cams 6 and 6 are driven to rotate by the emergency use power supply 1 for the predetermined time and the pressure roll Fp is rotated. Move to the nip release position (separation position). Incidentally, at the time of the emergency off, the pressure roll Fp can be moved to the nip release position by the emergency power supply 1 regardless of the presence or absence of the sheet S sandwiched in the fixing area Q5. In FIG. 8, an emergency power supply 1 is connected to the controller C and the nip forming motor drive circuit Df.

(Explanation of Flowchart of Embodiment 2) FIG.
9 is a flowchart of emergency fixing nip release control.
The processing of each ST (step) in the flowchart of FIG.
This is performed according to a program stored in the ROM of the controller C. The emergency fixing nip release control flow shown in FIG. 9 is started when the power is turned on. In FIG. 9, when the emergency fixing nip release control flow is started, it is determined in step ST21 whether or not the copy start key is turned on. If no (N), ST21 is repeatedly executed. If yes (Y), the process moves to ST22. In ST22, it is determined whether or not an abnormality (emergency off) has occurred. If no (N), the process moves to ST23. In ST23, it is determined whether the job is completed. If no (N), the ST
Returning to 22, if yes (Y), the process returns to ST21. If the answer is yes (Y) in ST22, the process moves to ST24.

In ST24, the display unit UIa indicates that an abnormal stop has occurred. In ST25, the fixing area Q
Judge whether there is paper in 5 or not. This determination is based on the fixing area Q5.
The presence / absence of a sheet is determined by a sensor (not shown) disposed on the upper and lower sides in the sheet conveyance direction. If no (N), the process returns to ST21, and if yes (Y), the process moves to ST26. In ST26, the nip forming motor Mf is turned on. In ST27, it is determined whether or not the pressure roll Fp is at the nip release position (separation position). S for no (N)
T27 is repeatedly executed, and if yes (Y), the process moves to ST28. In ST28, the nip forming motor Mf is turned off, and the process returns to ST21. Therefore, when there is a sheet S in the fixing area Q5, the pressure roll Fp moves to the nip release position (separation position), and the sheet S is easily removed. There is no need to take out the paper S that has stopped moving in Q5. The pressure roll Fp moved to the nip release position is
Upon return, it moves to the pressure contact position.

(Embodiment 3) FIG. 10 is an enlarged explanatory view of a main part of a sheet feeding device of an image forming apparatus according to Embodiment 3 of the present invention. FIG.
FIG. 1 is a block diagram of a main part of a control portion of a third embodiment of the image forming apparatus of the present invention. In the description of the third embodiment, components corresponding to the components of the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. The third embodiment differs from the first embodiment in the following points, but has the same configuration as the first embodiment in other points.

In FIG. 10, each of the paper feed trays TR1 and TR2 arranged in multiple stages of the image forming apparatus of the third embodiment has rails 11 (only the paper feed side is shown) provided at both ends (left and right directions in the drawing) in the paper feed direction. ) So as to be movable in the direction perpendicular to the plane of the drawing. An ascending rotary shaft 13 is disposed outside the paper front end support wall 12 at the front end of each of the paper feed trays TR1 and TR2 in the paper feeding direction (left side in the drawing).
One end of the letter-shaped lifting lever 14 is fixed. The other end of the raising lever 14 is in contact with the lower surface of the sheet placing plate 16, and a sheet (recording sheet) S is placed on the upper surface of the sheet placing plate 16. When the paper feed trays TR1 and TR2 storing the paper S are stored in the image forming apparatus, the raising rotation shaft 13 rotates and the raising lever 14
Are configured to lift the sheet mounting plate 16 and hold the upper surface of the sheet at an appropriate position.

A paper feeder 17 is provided above the paper feed side of the paper feed tray TR1. The paper feeder 17 has a pickup roll elevating member 18. A rotating shaft 18a of the pick-up roll elevating member 18 is rotatably supported by a frame 19 of the sheet feeding device 17, and the pick-up roll elevating member 18 rotatably supports the pickup roll Rp. The pick-up roll elevating member 18 is always held at the upper position, but when the paper S is taken out, the solenoid SL (see FIG. 11) is turned on and the pick-up roll elevating member 18 is moved to the lower position ( Paper tray T
R2). When the pick-up roll elevating member 18 moves to the lower position, the feed roll Rk is rotated by the feed roll driving motor Mr (see FIG. 11), and the gear Gs of the feed roll Rk is changed to the gear G3, The torque is transmitted to the gear Gp of the pickup roll Rp via G4 and G5.

The paper S taken out by the pickup roll Rp is separated one by one by a paper feed roll Rk and a retard roll Rs, and sent out to the paper transport guide 21 on the paper feed end side of the paper feed tray TR. The fed sheet S is transported upward by a plurality of transport rolls Ra provided on the paper transport guide 21. The paper transport guide 21 has an outer guide member 21a and an inner guide member 21b, and the outer guide member 21a and the inner guide member 21b form a sheet transport path SH1. The outer guide member 21a is configured to be able to be separated from the inner guide member 21b, and when the outer guide member 21a is separated from the inner guide member 21b, a sheet jammed in the sheet conveying path SH1. It is easy to take out S. In addition, the symbol R
The sheet conveying device SH is composed of the components indicated by a, Rr, Rs, Rp, Rk, and SH1.

In FIG. 11, the controller C of the image forming apparatus according to the third embodiment includes a tray-side sheet detection sensor SN1 installed at the paper feed side end of each of the paper feed trays TR1 and TR2, and the inner guide member. Signals from a plurality of sheet position sensors SN2 provided in 21b and other signal output elements are input. The controller C of the third embodiment
Are connected to a solenoid operating circuit Ds, a feed roller driving motor driving circuit Dr, and other control elements. The solenoid operation circuit Ds operates the solenoid SL. The feed roll driving motor drive circuit Dr drives the feed roll RK and the pickup roll Rp via the feed roll drive motor Mr.

The controller C according to the third embodiment has the following functions. C4: Emergency control means Emergency control means C4 is emergency paper feed roll drive control means C4
have a. C4a: Emergency paper feed roll drive control means The emergency paper feed roll drive control means C4a is a sheet to be taken out of the paper feed tray TR by any one of the tray side sheet detection sensors SN1 during an emergency OFF. When the sheet S to be taken out is detected, the sheet feeding roll RK and the pickup roll Rp are moved to a position where the sheet S to be taken out can be easily taken out from the image forming apparatus, that is, a position where the leading end of the sheet S is detected by each of the sheet position sensors SN2. Drive.

In FIG. 11, an emergency power supply 1 is connected to the controller C, the solenoid operating circuit Ds, and the paper roll driving motor driving circuit Dr. In addition,
Instead of the sheet position sensor SN2, a sheet position sensor (SN2 ') shown in FIG. 10 may be provided on the outer guide member 21a. In this case, the paper roll can be transported to the position of the sheet position sensor (SN2 ') provided on the outer guide member 21a by driving the transport roll Ra at the time of emergency off.

(Explanation of Flowchart of Embodiment 3) FIG.
2 is a flowchart of the emergency paper feed roll control. The processing of each ST (step) in the flowchart of FIG.
This is performed according to a program stored in the ROM of the controller C. The emergency paper feed roll control flow shown in FIG. 12 is started when the power is turned on. In FIG. 12, when the emergency paper feed roll control flow starts, step S
At T31, it is determined whether the copy start key has been turned on. If no (N), ST31 is repeatedly executed. If yes (Y), the process moves to ST32. In ST32, it is determined whether or not an abnormality (emergency off) has occurred. If no (N), the process moves to ST33. In ST33, it is determined whether the job is completed. If no (N), the above ST32
And if yes (Y), the process returns to ST31. In the case of YES (Y) in ST32, the process moves to ST34.

In ST34, the display unit UIa indicates that an abnormal stop has occurred. In ST35, it is determined whether or not there is a sheet S at the position of the tray side sheet detection sensor SN1. If no (N), the process returns to ST31, and if yes (Y), the process moves to ST36. In ST36, it is determined whether or not the sheet S is present on the sheet position sensor SN2. If no (N), the process returns to ST31; if yes (Y), the process moves to ST37. In ST37, the following operation is performed. (1) Solenoid SL on (2) Feed roll motor Mr on

In ST38, the sheet position sensor S
It is determined whether there is a sheet S at the position of N2. If no (N), ST38 is repeatedly executed, and if yes (Y), S38 is executed.
Move to T39. In ST39, the following operation is performed. (1) Solenoid SL off (2) Feed roll motor Mr off After this operation, the process returns to ST31. The sheet S at the position of the sheet position sensor SN2 can be taken out from the sheet guide 21 by opening the outer sheet guide member 21a.

(Embodiment 4) FIG. 13 is a block diagram of a main part of a control portion of an image forming apparatus according to Embodiment 4 of the present invention.
In the description of the fourth embodiment, the same reference numerals are given to the components corresponding to the components of the third embodiment, and the detailed description is omitted. The fourth embodiment differs from the third embodiment in the following points, but has the same configuration as the third embodiment in other points. In FIG. 13, the emergency power supply 1 used in the image forming apparatus of the fourth embodiment is configured by a capacitor instead of the large-capacity capacitor. The emergency use power supply 1 of the fourth embodiment is connected to power supply conductors La and Lb from the normal power supply to the controller C, the solenoid operation circuit Ds, and the paper feed roll drive motor drive circuit Dr via an on / off switch SW. It is connected. The on / off switch SW is turned on when the main switch is on in an emergency off state. Example 4
Also has the same effect as the third embodiment.

(Modifications) Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, but falls within the scope of the present invention described in the appended claims. Thus, various changes can be made. Modified embodiments of the present invention will be exemplified below. (H01) In the first embodiment, the large-capacity capacitor 1 serving as the emergency power supply is connected only to the second developing devices Gc and Gk. However, the emergency power supply 1 is also connected to the first developing devices Gy and Gm. It is possible to perform a purge when a power failure occurs during the developing operation. (H02) In the first embodiment, it is possible to apply a bias to the developing roll 26c when purging at the time of emergency off. (H03) The emergency power supply used in the image forming apparatus of the present invention is connected to the components of the image forming apparatus other than the developing units Gc and Gk, the fixing device F, and the sheet conveying device SH described in each of the above-described embodiments. It is sometimes possible to drive for a predetermined time.

[0062]

The above-described image forming apparatus of the present invention has the following effects. (E01) Activating a predetermined part in the image forming apparatus for a predetermined time at the time of emergency turning off of a normally used power supply (normally used power supply) due to occurrence of an abnormal situation during an image forming operation of the image forming apparatus,
Recovery processing such as paper jam processing after recovery and removal of residual toner on the developing roll can be easily performed.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a first embodiment of a color image forming apparatus having a sheet conveying belt in contact with a plurality of image carriers.

FIG. 2 is an enlarged view of a main part of FIG. 1;

FIG. 3 is a block diagram of a main part of a control portion of the image forming apparatus according to the first embodiment of the present invention.

FIG. 4 shows a Y (yellow) developing device and a C (cyan) developing device of the image forming apparatus according to the first embodiment of the present invention.
6 is a time chart of a normal operation of the developing device.

FIG. 5 is a time chart at the time of emergency off of a Y (yellow) developing device.

FIG. 6 is a time chart when the C (cyan) developing device is turned off in an emergency.

FIG. 7 is a flowchart of an emergency developing roll control process of the image forming apparatus according to the first embodiment of the present invention.

FIG. 8 is an enlarged explanatory view of a main part of a fixing device used in an image forming apparatus according to a second embodiment of the present invention.

FIG. 9 is a flowchart of emergency nip release control in an emergency.

FIG. 10 is an enlarged explanatory view of a main part of a sheet feeding device of an image forming apparatus according to a third embodiment of the present invention.

FIG. 11 is a third embodiment of the image forming apparatus of the present invention.
3 is a block diagram of a main part of a control part of FIG.

FIG. 12 is a flowchart of emergency paper feed roll control.

FIG. 13 is a fourth embodiment of the image forming apparatus of the present invention.
3 is a block diagram of a main part of a control part of FIG.

14 is a time chart showing an example of an operation at the time of normal stop and an operation at the time of emergency off in the conventional purge type developing device, FIG. 14A is a time chart at the time of normal stop, and FIG. 14B. Is a time chart at the time of emergency off.

[Explanation of symbols]

C1a: Emergency purging operation executing means, C2: Developer purging operation executing means, C3a: Emergency fixing roll pressure contact / separation driving member control means, C4a: Emergency paper feeding roll drive controlling means, F: Fixing device, Fp, Fh: Fixing roll, Gc, Gk
... Second developing device, Gy, Gm ... First developing device, Gy, Gm, G
c, Gk: developing unit, La, Lb: power supply lead, PR1, PR2
... Image carrier, Q5 ... Fixing area, ROS1, ROS2 ... Latent image writing device, Ra ... Convey roll, Rk ... Paper roll, Rp ...
Pickup roll, SH: sheet transport device, sheet transport path, SW: on / off switch, S: recording sheet, SN2
... Sheet position sensor, TR1, TR2 ... Paper feed tray, U ...
Image forming apparatus, 1 emergency power supply, 6 fixing roll press-contact / separation drive member, 25y, 25m, 25c, 25k developer transfer roll, 26y, 26m, 26c, 26k development roll, (C1; C3 C4) emergency control means.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yu Yu Ono 2274 Hongo, Ebina-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Yutaka Yakabe 2274 Hongo, Ebina-shi, Kanagawa Prefecture Fuji Xerox Co., Ltd. Reference) 2H027 DA03 DA38 DC03 ED17 ED25 EJ17 EJ18 ZA01 ZA07 5B011 DA13 EA10 EB08 GG12 JB03 5G015 GB02 HA14 JA06 JA10 JA32 JA62 KA06 9A001 BB01 BB03 BB04 DD11 HH31 HH34 JJ35 KK31 KK16 KK29 KK29

Claims (7)

[Claims] An image forming apparatus having the following requirements (A01) and (A02): (A01) a power supply (normally used) which is normally used when an abnormal situation occurs during an image forming operation of the image forming apparatus; (A02) an emergency use power supply used in place of the normal use power supply at the time of emergency off of the (use power supply); (A02) automatically operating a predetermined component by the emergency use power supply for a predetermined time at the emergency off; Emergency control means to stop from. 2. The image forming apparatus according to claim 1, further comprising the following requirement (A03): (A03) the emergency connected to a power supply lead from the normal power supply to the predetermined component. Use power supply. 3. The image forming apparatus according to claim 1, wherein the image forming apparatus satisfies the following requirement (A04).
The emergency power supply comprising a rechargeable capacitor connected to a power supply lead from the normal power supply to the predetermined component. 4. The image forming apparatus according to claim 1, wherein the image forming apparatus satisfies the following requirement (A05).
The emergency power supply comprising a capacitor connected via an on / off switch to a power supply lead from the normal power supply to the predetermined component. 5. The image forming apparatus according to claim 1, further comprising the following requirements (A06) to (A010): (A06) a surface which is rotated by a latent image writing device. An image carrier on which an electrostatic latent image corresponding to an image of a different color is sequentially written, (A07) a first developing device arranged opposite to the surface of the image carrier and fixedly arranged around the image carrier; A plurality of developing devices including a developing device and a second developing device, wherein the electrostatic latent image is developed into a toner image with a developer of a color corresponding to the electrostatic latent image of the color written on the surface of the image carrier. (A08) a developing roll disposed adjacent to the surface of the image carrier, a non-magnetic sleeve rotatably disposed adjacent to the developing roll, and disposed inside the sleeve; Has a magnetic force generating member and adheres to the sleeve surface when the sleeve rotates (A09) the plurality of developer units each having a developer transport roll that supplies the developer to the development rolls; and (A09) the developer at the end of the development operation of the development unit that has performed the development operation of the plurality of development units. A developer that executes a developer purge operation of causing the developer on the developing roll surface to be attracted to the developer transport roll and purging from the developing roll surface by rotating the developing roll for a predetermined period with the transport roll stopped. Means for performing a purge operation,
(A010) The emergency control means having an emergency purge operation executing means for executing the developer purge operation by the emergency power supply for the predetermined time when the emergency is turned off. 6. The image forming apparatus according to claim 1, wherein the image forming apparatus has the following requirements (A011) to (A013): (A011) a pair of fixing rolls, A fixing device for fixing a toner image on a recording sheet passing through a fixing area formed by a pressure-contact area of a pair of fixing rolls; (A012) a separation unit separated from a pressure-contact position where the pair of fixing rolls are pressed against each other; (A013) The predetermined predetermined component is the fixing roll pressing / separating drive member, and the pair of fixing rolls are driven by the fixing roll during the predetermined time. This is the time required to move from the pressure contact position to the separation position. During the emergency OFF, the emergency use power supply drives the fixing roll pressure contact / separation driving member by the emergency use power supply for the predetermined time. The emergency control means having a separation drive member control means. 7. The image forming apparatus according to claim 1, further comprising the following requirements (A014) to (A016): A sheet conveyance device having a pickup roll to be taken out, a paper supply roll to feed the taken out recording sheet to a sheet conveyance path, and a conveyance roll to convey the paper fed to the sheet conveyance path; A sheet position sensor for detecting whether or not the recording sheet fed by the paper feed roll is conveyed to a position where it can be easily removed; (A016) the predetermined component is a paper feed roll; This is the time required for the recording sheet fed by the paper feed roll to move from the emergency-off position to the easy-to-remove position. The emergency control means further comprising an emergency paper feed roll drive control means for rotating the paper feed roll for the predetermined time.