JPH09114311A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the time required for ejecting a first copy at the time of supplying power. SOLUTION: In this image forming device; a toner image formed on the surface of an image carrier is transferred and fixed on paper, and heaters incorporated in a heating roll for fixing 19a and a heating roll for pressuring 19b are heated so that either the heating roll 19a or 19b may attain set temperature specified time earlier than the other. Then, it is provided with a heating controller which stops the heating of the heater incorporated in either roll 19b when the roll 19b attains the set temperature, and an image quality adjusting operation controller which starts image quality adjusting operation simultaneously with stopping the heating of the heater incorporated in either roll 19b.

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 a multifunction peripheral and a copying machine having a facsimile function and a copying function, and more particularly to an image forming apparatus having an improved start-up characteristic when the power is turned on.

[0002]

2. Description of the Related Art In this type of image forming apparatus, a fixing device warming-up time for raising the temperature of the fixing device to an operation standby temperature and an image density change are set by the time the power is turned on until an image can be formed. The time required for the image quality adjustment operation for adjustment and the like is necessary. Further, in the color image forming apparatus, time required for adjustment such as gain adjustment and offset adjustment for each color of the read image is also required. And the temperature of the fixing device reaches the standby position,
In addition, after the above-mentioned adjustments have been carried out, image formation becomes possible and the copying machine becomes ready for copying. That is, in this type of image forming apparatus, a certain time required for rising is required when the power is turned on. And, the shorter the time required to rise is, the better the usability is.

In the image forming apparatus, the following techniques are conventionally known as techniques for reducing the rise time. (J01) Japanese Patent Application Laid-Open No. 57-54970 In this publication, a transfer sheet is conveyed from a sheet feeding device to an inlet of a heating and fixing device from a time point when the surface temperature of a heating and fixing roller reaches a fixing possible temperature. There is described a technique for enabling the copy start switch at an earlier time than the time required for. (J02) Technology disclosed in Japanese Patent Laid-Open No. 60-123880 In this publication, it is output that a copy is possible below the fixing temperature, and then the copying operation is performed when the temperature reaches the fixing temperature. Is listed. (J03) Technology described in Japanese Patent Application Laid-Open No. 64-91167 In this publication, two types of CPM (Copy Per Minute) speed are set, that is, when the fixing temperature is low and when the fixing temperature is high.
Slow CPM if fixing temperature is not high enough
A device is described which allows copying at speed.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
All of 1) to (J02) are aimed at shortening the start-up time of the image forming apparatus, and the image forming is prepared before the fixing temperature reaches a temperature at which copying is possible, or when the fixing temperature is not sufficiently high. Is fixing at a slow speed. However, the above-mentioned respective prior arts do not consider the maximum power consumption of the image forming apparatus at all.

In some cases, a device for heating both a pair of rolls constituting the fixing device is used. That is,
In some cases, an apparatus in which the fixing device is composed of a fixing heating roll and a pressing heating roll is used. The present applicant has conventionally considered the following device (J04) as a fixing device that heats both a pair of rolls. (J04) Device that operates as shown in the time chart of FIG. 4. In FIG. 4, after the power is turned on at time t0, the heaters of the fixing heating roll and the pressing heating roll of the fixing device are first turned on.
Then, heating of each roll is started. Immediately after the pressurizing heating roll reaches a predetermined temperature at time t1 and turns off, II
Turn on the exposure lamp of T (image input terminal)
When set to N, the AGC (auto gain controller) and the AOC (auto offset controller) are adjusted, that is, the image reading parameters are adjusted.

At the time t2, the fixing heating roll reaches a predetermined temperature and becomes ready to start the copying operation.
When the copy start switch is turned on at a time (for example, the time t2) after that, the image quality adjustment mode for adjusting the image density is automatically started, and the paper is conveyed at the end time t3 of the image quality adjustment. It is supposed to be started. Since the image quality adjustment mode must be performed after the copy operation can be started, conventionally, the sequence operation is started by using the ON signal of the copy start switch as a trigger.

During the copying operation, the fixing roll, the exposure lamp, and the main motor are driven simultaneously, but the pressure roll is controlled so as not to be turned on at the same time. That is, after the time t3, when the temperature of the pressure roll heater becomes equal to or lower than a predetermined value, the pressure roll heater is turned on while at least one of the fixing roll heater and the main motor is off. The temperature of the pressure roll is kept above a predetermined value.

The meanings of the times T1 to T4 in FIG. 4 are as follows. T1: Time required for heating the fixing device (warm-up time)
That is, T3 + T4 T2: Time required for image quality adjustment mode (time required for process control setup cycle) T3: Time required for heating heating roll for pressurization (warm-up time) T4: Difference in required heating time between heating roll for fixing and heating roll for pressurization (Warm-up time difference) In FIG. 4, the time T from the time t0 when the image forming apparatus is turned on to the copy discharge, that is, the time T required for discharging the first copy when the power is turned on can be expressed by the following equation. T = T1 + T2 + T5 ………………………………………………………… (1) However, T5 is the time required from the start of feeding copy paper to the discharge of copy. Generally, it is the time required from the start of the copy start switch to the discharge of the copy when the copy is ready. As can be seen from the above formula (1), the required time T for ejecting the first copy when the power is turned on is T1 + T2 longer than the time T5 required for turning on the copy start switch and discharging the copy during steady operation. ing.

In the fixing device, if the maximum power consumption of the image forming device may be large, if the necessary power is simultaneously supplied to the fixing heating roll and the pressure heating roll to heat the image forming device, the image forming device starts up. Time will get faster. However, the capacity of household power supply is 1.5KVA
In many cases (1500 W), the upper limit of the instantaneous maximum power consumption of the image forming apparatus is limited in consideration of home use. Moreover, in a general color image forming apparatus, as shown in FIG. 4, both a fixing roll and a pressing roll of the fixing device provided with a heating roll for fixing and a heating roll for pressurizing are often used. Therefore, a large amount of electric power is required to start these (warm up).

In the image adjustment mode, a temporary image is formed on the image carrier, the density of the temporary image is detected, and parameters relating to the image density such as operating conditions of image output components ( That is, although the work for adjusting the image output parameter) is performed, this work consumes a large amount of power because the main motor of the image forming apparatus is operated. Therefore, in the image adjustment mode in the conventional image forming apparatus shown in FIG. 4, after both the fixing heating roll and the pressing heating roll have risen above a predetermined temperature and are turned off (after warm-up), I was going to do it.

However, as described above, in the conventional image forming apparatus, the time T required to eject the first copy when the power is turned on is compared with the time T5 required from the start of the copy start switch to the ejection of the copy in the steady operation. By the way, it is longer by T1 + T2. In order to use the image forming apparatus comfortably, it is desirable to shorten the required time T for ejecting the first copy when the power is turned on. The present invention has been made in view of the above circumstances, and has an object of the following content (O01). (O01) Shorten the time required to eject the first copy when the power is turned on.

The present inventor has made the following thoughts as a result of the examination for solving the above problems. That is, in the image quality adjustment mode when the power is turned on, the toner of the toner image for image density adjustment developed on the image carrier is collected by the cleaning device, and it is not necessary to transfer or fix it. Therefore, it is possible to execute the image quality adjustment mode even if both the fixing roll and the pressure roll of the fixing device have not reached the predetermined temperature. Therefore, after one roll of the fixing device has finished warming up, the other roll is heated while the exposure lamp and the main motor are operated to adjust the gain and IOT of the image reading unit of the IIT.
(Image output terminal) image quality can be adjusted at the same time. The present invention has been completed based on the above-mentioned examination results.

[0013]

The present invention devised to solve the above problems will now be described. The elements of the present invention facilitate the correspondence with the elements of the embodiments described later. Therefore, the reference numerals of the elements of the embodiment enclosed in parentheses are added. The reason why the present invention is described in association 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.

(First Invention) In order to solve the above problems,
The image forming apparatus of the first invention of the present application has the following requirements, (Y01) a latent image writing device (12) for writing a latent image on the surface of an image carrier (13), (Y02) ) Developing device (15Y, 15M, 15C, 15K) for developing the latent image on the surface of the image carrier (13) into a toner image, (Y03) arranged at a set transfer position along the surface of the image carrier (13) The image carrier (1
3) Transfer device (17) for transferring the toner image on the surface (Y04) The paper stored in the paper feed trays (20a to 20e) is taken out and sequentially conveyed to the transfer position, the fixing position, and the paper discharge tray (22). Paper transport device (H), (Y0
5) Heating roll for fixing (19a) and heating roll for pressurizing (19b) having a heater arranged in the fixing position.
Fixing device (19) having (Y06) set temperature of heating roll for fixing (19a) and heating roll for pressing (19b)
Set temperature storage means (IOTCP for storing the set temperature of
U), (Y07) The fixing heating roll (19a) and the pressing heating roll (19a) and the pressing heating roll (19b) so that one of the fixing heating roll (19a) and the pressing heating roll (19b) reaches the set temperature earlier than the other by a predetermined time. A heating control device that heats a heater built in the heating roll (19b) and stops heating of the heater built in the one roll (19b) when the one roll (19b) reaches a set temperature ( IO
(TCPU), (Y08) An image quality adjustment operation control device (IOTCPU) for stopping the heating of the heater built in the one roll (19b) and at the same time starting the image quality adjustment operation.

(Second Invention) An image forming apparatus according to a second invention of the present application is characterized by having the following requirements.
(Y01) A latent image writing device (12) for writing a latent image on the surface of the image carrier (13), and (Y02) a developing device (15Y, 15M, for developing the latent image on the surface of the image carrier (13) into a toner image. 15
(C, 15K), (Y03) The toner image on the surface of the image carrier (13) is transferred onto a sheet which is arranged at a set transfer position along the surface of the image carrier (13) and passes through the transfer position. Transfer device (17) (Y04) A paper transport device (H) that takes out the paper stored in the paper feed trays (20a to 20e) and sequentially transports the paper to the transfer position, the fixing position, and the paper discharge tray (22). Y0
5) Heating roll for fixing (19a) and heating roll for pressurizing (19b) having a heater arranged in the fixing position.
Fixing device (19) having (Y06) set temperature of heating roll for fixing (19a) and heating roll for pressing (19b)
Set temperature storage means (IOTCP for storing the set temperature of
U), (Y07) The fixing heating roll (19a) and the pressing heating roll (19a) and the pressing heating roll (19b) so that one of the fixing heating roll (19a) and the pressing heating roll (19b) reaches the set temperature earlier than the other by a predetermined time. A heating control device that heats a heater built in the heating roll (19b) and stops heating of the heater built in the one roll (19b) when the one roll (19b) reaches a set temperature ( IO
TCPU), (Y09) Copy start command storage means (main CPU) for storing that the copy start switch is input when the copy start switch is input before the image quality adjusting operation is completed, (Y010) Image quality adjusting operation control means for starting the image quality adjusting operation at the same time as the two conditions that the heating of the heater built in one roll (19b) is stopped and that the copy start switch is input ( IOTCPU).

(Embodiment 1 of the present invention) An image forming apparatus according to Embodiment 1 of the present invention is characterized in that the image forming apparatus of the first invention of the present application has the following requirements: (Y001 ) A paper feeding operation control means (IOTCPU) for starting the feeding of copy paper at the same time when the two conditions of the completion of the image quality adjusting operation and the input of the copy start switch are satisfied.

(Embodiment 2 of the Invention) An image forming apparatus according to Embodiment 2 of the present invention is characterized in that the image forming apparatus of the second invention of the present application has the following requirements. ) Paper feed operation control means (IOTCP) for starting the feeding of copy paper at the same time when the image quality adjusting operation is completed
U).

(Embodiment 3 of the present invention) An image forming apparatus according to Embodiment 3 of the present invention is an image forming apparatus according to any one of the first invention, the second invention, and Embodiments 1 and 2 of the present invention. (Y003) A display unit for displaying that the copy start switch is ready for reservation at the same time as the heating of the heater incorporated in the one roll (19b) is stopped. .

[0019]

Next, the operation of the present invention having the above features will be described. (Operation of First Invention) In the image forming apparatus of the present invention having the above-mentioned characteristics, the latent image writing device (12) includes the image carrier (1
3) Write a latent image on the surface. Developing device (15Y, 15
M, 15C, 15K) develops the latent image on the surface of the image carrier (13) into a toner image. The paper transport device (H) takes out the paper stored in the paper feed trays (20a to 20e), and sequentially transports the paper to a transfer position, a fixing position, and a paper discharge tray (22). A transfer device (17) arranged at a set transfer position along the surface of the image carrier (13) transfers the toner image on the surface of the image carrier (13) to a sheet passing through the transfer position.

The fixing device (1
9) is a fixing heating roll (19a) with a built-in heater
And a heating roll (19b) for pressurization. The set temperature storage means (IOTCPU) is a set temperature of the heating roll for fixing (19a) and a heating roll for pressurization (19b).
Store the set temperature of. The fixing heating roll (19
a) and the heater built in the pressurizing heating roll (19b) are arranged so that one of the fixing heating roll (19a) and the pressurizing heating roll (19b) reaches the set temperature earlier than the other by a predetermined time. Fever. The heating control device (IOTCPU) stops the heating of the heater built in the one roll (19b) when the one roll (19b) reaches the set temperature. The image quality adjustment operation control unit (IOTCPU) stops the heating of the heater built in the one roll (19b) and simultaneously starts the image quality adjustment operation. As described above, the fixing heating roll (19) a of the fixing device (19) and the pressing heating roll (1
9b) is heated so that the temperature of one roll (19b) reaches a predetermined temperature quickly, and the heating of the heater built in the one roll (19b) is stopped, and at the same time the image quality adjusting operation is started. The time required for the image forming apparatus to start up when the power is turned on can be shortened without increasing the maximum power consumption.

(Operation of Second Invention) In the image forming apparatus according to the first embodiment of the present invention, when the copy start switch is pressed before the image quality adjusting operation is completed, the copy start command storage means (main The CPU) stores that the copy start switch has been pressed. When the image quality adjusting operation control means (IOTCPU) satisfies two conditions, that is, the heating of the heater built in the one roll (19b) is stopped and that the copy start switch is input. At the same time, the image quality adjustment operation is started. In this image quality adjusting operation, the main motor of the image forming apparatus is driven, and there is a possibility of being injured when the operator inserts the tip of his hand into the image forming apparatus. Therefore, for the safety of the operator, the image adjusting operation is started after the operator inputs the copy start switch. Then, if the copy start switch is pressed before the heating of the heater built in the one roll (19b) is stopped, the image quality adjusting operation is started at the same time as the heating of the heater is stopped. in this case,
Since no useless waiting time occurs, the image quality adjusting operation at power-on can be executed in the shortest time and safely.

(Operation of Embodiment 1 of the Present Invention) In the image forming apparatus according to Embodiment 1 of the present invention, the paper feed operation control means (IOTCPU) is configured to notify the completion of the image quality adjustment operation and the copy start switch. When the two conditions that there is an input are satisfied, the feeding of copy paper is started at the same time. In this case, there is no useless waiting time from the power-on to the start of feeding the copy paper, so that the first image formation at the power-on can be performed in the shortest time.

(Operation of Second Embodiment of the Present Invention) In the image forming apparatus according to the second embodiment of the present invention, the sheet feeding operation control means (IOTCPU) feeds the copy sheet at the same time when the image quality adjusting operation is completed. Start. In this case, there is no useless waiting time from the power-on to the start of feeding the copy paper, so that the first image formation at the power-on can be performed in the shortest time.

(Operation of Embodiment 3 of the Present Invention) In the image forming apparatus of Embodiment 3 of the present invention, at the same time as the heating of the heater built in the one roll (19b) is stopped, the display section is ready (Ready). ) State, that is, the copy start switch can be reserved. Therefore, even an operator who does not know that it is possible to make a copy start reservation can make a copy start reservation by pressing the copy start switch when he sees the display. In that case, the image quality adjustment operation is started without causing unnecessary waiting time, and at the same time as the end of the image quality adjustment operation, the feeding of copy paper is started. In other words, even an operator who does not know that it is possible to make a reservation for copy start does not cause unnecessary waiting time from the time the power is turned on until the start of feeding copy paper, and the first image formation when the power is turned on. Can be done in a short time.

[0025]

Embodiments of the image forming apparatus of the present invention will be described below with reference to the drawings, but the present invention is not limited to the following embodiments. (Embodiment 1) FIG. 1 is an overall explanatory view of an image forming apparatus U according to Embodiment 1 of the present invention. FIG. 2 is a time chart of the operation of the image forming apparatus of the first embodiment when the power is turned on.

In FIG. 1, an image forming apparatus U includes a digital color copying machine (hereinafter also simply referred to as a "copying machine") A as an image forming apparatus having a platen glass (transparent document table) A1 on the upper surface thereof, and the platen. The automatic document feeder B is detachably mounted on the glass A1.

Next, the copying machine A will be described. The copying machine A includes an image input terminal IIT (hereinafter also simply referred to as "IIT") as an image reading section and an image output terminal IOT as an image recording operation section, which are sequentially arranged below the platen glass A1. (Hereinafter, also simply referred to as “IOT”).

The IIT (image input terminal) as the image reading section has an exposure scanning optical system 1 below the platen glass A1. The exposure scanning optical system 1 has an exposure lamp 2 for document illumination mounted on a full rate carriage and a first mirror 3. The exposure scanning optical system 1 has a second mirror 4 and a third mirror 5 mounted on a half-rate carriage that moves at half the speed of the full-rate carriage. Further, the exposure scanning optical system 1 has an imaging lens 6 supported by an IIT frame. The imaging lens 6
Reflecting from the original on the platen glass A1 and further sequentially,
It has a function of converging the original reflected light reflected by the first, second and third mirrors to an image sensor 7 constituted by a solid-state image pickup device (CCD sensor). Image sensor 7
Has a function of converting the reflected light of the document converged on the image pickup surface into an electric signal. Further, the IIT has a signal processing unit S for reading out an electric signal obtained by the image sensor 7 and outputting it as image data, and a user interface UI for allowing the user of the image forming apparatus U to input and operate an operation command signal such as copy start. have. The user interface UI has a display unit (not shown), and the display unit is configured to display information on the current setting state of the image forming apparatus U.

The signal processing section S includes an analog circuit S1,
Digital correction circuit S2 and IPS (Image Process
ing System). The analog circuit S1 has a function of performing gain adjustment, offset adjustment, A / D conversion, etc. of the output signal from the image sensor 7. The gain adjustment and the offset adjustment of the analog circuit S1 are performed when the power of the image forming apparatus U is turned on, and the gain and offset values of the read image signal of the image sensor 7 are set. Also, the digital correction circuit S2
Has a function of performing shading correction, gap correction (correction of color registration due to a gap between read pixel columns of a line sensor using a reduction optical system), etc. on an output signal from the analog circuit S1. Also,
The IPS performs color correction and ENL (Equal Neutral Lightnes) on the output signal from the digital correction circuit S2.
LUT (Look Up Tabl) to convert to s (equivalent neutral brightness)
e) That is, it has a function of performing gamma correction of read data, correction using a LUT for performing color gradation correction, and the like.

Further, the signal processing section S includes the circuits S
IPS (Image Proces) that controls the operation of 1, S2 and IPS
sing system) CPU, a motor control CPU for controlling the operation motor of the exposure scanning optical system 1, a main CPU, and the like. The main CPU has a function of controlling operations of the IPS CPU, the motor control CPU, and the like in accordance with an operation signal of the user interface UI. Further, the main CPU has a function of storing the copy start switch, if the copy start switch is pressed during warming up of the fixing device 19 (see FIG. 1) started after time t0 when the power is turned on as shown in FIG. Have

The IOT (image output terminal) as the image recording operation section uses a laser drive circuit 11 for outputting a laser drive signal according to an image signal output from the image processing circuit IPS, and a laser beam. Optical writing scanning device (that is, latent image writing device) 1
2. An image carrier (photosensitive drum) 13 on which an electrostatic latent image is written by a laser beam, a charging charger 14 arranged around it, Y (yellow), M (magenta), C
(Cyan), K (black) color developing device 15, a transfer drum 16, a transfer charger (transfer device) 17 arranged at a transfer position, a cleaner unit 1
8, a fixing device 19, a plurality of paper feed trays 20a to 20e corresponding to the type of paper, a discharge roller 21, a paper discharge tray 22 and the like. The fixing device 19 has a fixing heating roll 19a and a pressing heating roll 19b, each of which has a heater built therein. In the first embodiment,
The power consumption of the fixing heating roll 19a is set to 650 W, and the power consumption of the pressurizing heating roll 19b is set to 525 W.

The IOT is the paper feed tray 20.
The sheets taken out from a to 20e are sucked at the suction position 16a, the transfer position between the transfer charger 17 and the image carrier 13, the fixing heating roll 19a and the pressure heating roll 19b.
A sheet conveying device H for sequentially conveying the sheet to the discharge tray 22 is provided at a fixing position between them. The paper transport device H is a paper supply device 23 that transports the paper taken out from the paper feed trays 20a to 20e to the suction position 16a, a transfer drum 16 that suctions the paper at the suction position 16a and transports the paper to the transfer position, The sheet is separated from the transfer drum 16 and fixed by the fixing device 19 to a discharge roller 21 for discharging the sheet to the discharge tray 22.

The original image read by the IIT (image input terminal) is developed as a toner image on the image carrier 13 and is formed as an unfixed toner image on the sheet attracted to the transfer drum 16. In the case of a color image, the paper adsorbed on the transfer drum 16 is Y,
The toner image of each color of M, C, K is transferred. The sheet on which the unfixed toner image is formed is separated from the transfer drum 16 and conveyed to the fixing device 19. Fixing device 19
Heat-fixes the unfixed toner image on the paper. The fixed paper (the paper on which the image is recorded and fixed) is discharged to the paper discharge tray 22 through the discharge roller 21.

A density sensor 24 is arranged downstream of the developing unit 15 in the rotational direction of the surface of the image carrier 13. The operation of each component of the IOT is configured to be controlled by the IOTCPU which operates in response to a signal from the main CPU. The IOTC
Detection signals from the density sensor 24, a sheet detection sensor (not shown), a fixing temperature sensor, and the like are input to the PU.
The IOTCPU has a CPU (central processing unit), a ROM (read only memory), a RAM (random access memory), an I / O (input / output interface), and the like. In the ROM of IOTCPU,
A program that controls the operation of each component of the IOT in accordance with the detected signals that are input and the input signal from the main CPU and the initial values of the image output parameters of the IOT are stored.

Further, in the ROM of the IOTCPU, when the image forming apparatus U is powered on, an image of a predetermined pattern is formed on the image carrier 13 with toner of each color at a predetermined timing, and the density of these pattern images is determined. Each developing device 15 having the toner of each color so that the pattern image has a predetermined density detected by the density sensor 24.
A bias potential control program to be applied between the Y, 15M, 15C and 15K developing rolls and the image carrier 13 is stored.

(Operation of Embodiment 1) Next, referring to FIG.
The operation of the embodiment having the above configuration will be described. FIG.
The operation of the image forming apparatus U shown in the time chart is performed according to the programs stored in the ROMs of the main CPU and IOTCPU. In FIG. 2, when the power source of the image forming apparatus U shown in FIG. 1 is turned on at time t0, the fixing heating roll 19a and the pressing heating roll 1 are pressed.
Each heater of 9b is turned on, and heating of each roll 19a, 19b is started. The temperature of the pressurizing heating roll 19b, which has been energized from the time t0, reaches a predetermined set value (value stored in the ROM of the IOTCPU) at the time t1 and is turned off. At this time t1, the exposure lamp 2 of the IIT and the ROS motor (not shown) for exposure scanning are turned on.
When set to N, adjustment of the AGC and AOC, that is, setting of document reading parameters is started. And IO
The TCPU (image quality adjustment operation control means) performs the image quality adjustment operation at the same time when two conditions are satisfied: the heating of the heater built in the pressure roll 19b is stopped and the copy start switch is input. Let it start.

If the copy start switch has been input by the time t1, the input is made in the RAM of the main CPU (copy start command storage means).
Is stored in Therefore, when the copy start switch is input by the time t1, the image quality adjustment for image density adjustment is performed at the same time as the heating of the heater incorporated in the pressure roll 19b is stopped (that is, at the time t1). The mode is automatically started and the setting of the image output parameters is started. Then, at the time t1, a ready signal is output to display on the display unit (not shown) of the image forming apparatus that the reservation of the copy start switch is possible. As mentioned above,
When the copy start switch is input after the time t0 when the power is turned on before the time t1 when the display is performed, the fact is stored. Therefore, actually, the time t1 when the display is performed
Previously, the copy start switch could be reserved.

In FIG. 2, since the setting of the original reading parameter is completed in a short time, the exposure lamp 2 is turned off in a short time. The fixing heating roll 19a
Reaches a predetermined temperature at time t2, and the fixing heating roll 19a
The heater built in is turned off. Also, the time t
3, the image output parameter setting is completed, and the image quality adjustment mode is completed. Then, at this time t3, the feeding of copy paper is started. In FIG. 2, time T1
The meaning of T4 is as follows. T1: Time required for heating the fixing device (warm-up time)
That is, T3 + T4 T2: Time required for image quality adjustment mode (time required for process control setup cycle) T3: Time required for heating heating roll for pressurization (warm-up time) T4: Difference in required heating time between heating roll for fixing and heating roll for pressurization (Warm-up time difference)

In the time chart shown in FIG. 2 of the first embodiment, it is possible to start feeding the copying paper from time t0 when the power is turned on to time t3 after time T3 + T2 has elapsed.
In the prior art shown in FIG. 4, from time t0 to time T1 + T2
Although the feeding of the copy sheet was started at time t3 after the lapse of time, T3 in FIG. 2 is shorter than T1 in FIG. 4, so in the case of FIG. It is possible to shorten the feeding start time t3 of the copy sheet.

(Second Embodiment) Next, a second embodiment of the image forming apparatus of the present invention will be described with reference to FIG. FIG.
6 is a time chart of the operation of the image forming apparatus of the second embodiment when the power is turned on. The second embodiment has the same configuration as that of the first embodiment except that the programs stored in the main CPU and the IOTCPU are different.

(Operation of Embodiment 2) Next, referring to FIG.
The operation of the second embodiment of the image forming apparatus of the present invention having the above-mentioned configuration will be described. The operation of the image forming apparatus U shown in the time chart of FIG. 3 is performed by the main CPU and IOTC.
This is performed according to the program stored in each ROM of the PU. In FIG. 3, when the power source of the image forming apparatus U shown in FIG. 1 is turned on at time t0, each heater of the fixing heating roll 19a and the pressurizing heating roll 19b is turned on,
The heating of each roll is started. The temperature of the pressurizing heating roll 19b, which has been energized from the time t0, reaches a predetermined set value (value stored in the ROM of the IOTCPU) at the time t1 and is turned off. At this time t1, the IIT
The exposure lamp 2 and the ROS motor (not shown) for exposure scanning are turned on to start the adjustment of the AGC and AOC, that is, the setting of the document reading parameter.

If the copy start switch has been input by the time t1, the input is made in the RAM of the main CPU (copy start command storage means).
Is stored in Therefore, if the copy start switch has been input by the time t1, the time T6 (T6 = approximately several hundred msec) has elapsed from the time when the ROS motor automatically started rotating at the time t1, and the ROS
At time t1 'after the motor has reached steady rotation and power consumption has decreased, the image quality adjustment operation control unit (IOTCPU)
As a result, the image quality adjustment mode for adjusting the image density is automatically started, and the setting of the image output parameters is started.

Since the setting of the original reading parameters is completed in a short time, the exposure lamp 2 is turned off in a short time. Further, the fixing heating roll 19a reaches a predetermined temperature at time t2, and the heater incorporated in the fixing heating roll 19a is turned off. Also, at the time t3, the setting of the image output parameters is completed, and the image quality adjustment mode is completed. Then, at the end time t3, the feeding of copy paper is started. The meanings of the times T1 to T4 in FIG. 2 are as follows. T1: Time required for heating the fixing device (warm-up time)
That is, T3 + T4 T2: Time required for image quality adjustment mode (time required for process control setup cycle) T3: Time required for heating heating roll for pressurization (warm-up time) T4: Difference in required heating time between heating roll for fixing and heating roll for pressurization (Warm-up time difference) T6: Time required for the ROS motor to reach steady rotation, that is, ROS motor start-up required time

In the time chart shown in FIG. 3 of the second embodiment, it is possible to start feeding the copying paper at time t3 after the time T3 + T6 + T2 has elapsed from the time t0 when the power was turned on. In the conventional technique shown in FIG. 4, from time t0 to time T1 +
Although the feeding of the copy sheet was started at time t3 after T2 has elapsed, T3 + T6 in FIG. 2 can be made shorter than T1 in FIG. 4, so that compared with the case in FIG. In this case, the feeding start time of the copy sheet can be shortened.

(Modifications) The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-mentioned embodiments, and the gist of the present invention described in the claims is not limited thereto. Various changes can be made within the range. Modifications of the embodiment of the present invention will be exemplified below. (H01) The present invention can be applied to an image forming apparatus other than a color copying machine, for example, a monochrome copying machine. (H02) In the present invention, the means for conveying the paper to the transfer position between the transfer means (transfer charger, transfer roll, etc.) arranged along the surface of the image carrier and the surface of the image carrier is
It is possible to configure without using a transfer drum.

[0046]

The above-described image forming apparatus of the present invention has the following effects. (E01) It is possible to shorten the time required to discharge the first copy when the power is turned on.

[Brief description of the drawings]

FIG. 1 is an overall explanatory diagram of an image forming apparatus U according to a first embodiment of the present invention.

FIG. 2 is a time chart of the operation of the image forming apparatus according to the first embodiment when the power is turned on.

FIG. 3 is a time chart of the operation of the image forming apparatus according to the second embodiment when the power is turned on.

FIG. 4 is a time chart of the operation of the conventional image forming apparatus when the power is turned on.

[Explanation of symbols]

H ... Paper transport device, IOTCPU ... Set temperature storage means (heating control device, image quality adjustment operation control device, paper feed operation control means), main CPU ... Copy start command storage means, 12 ...
Latent image writing device, 13 ... Image carrier, 15Y, 15M, 15
C, 15K ... Developing device, 17 ... Transfer device, 19 ... Fixing device, 19a ... Fixing heating roll, 19b ... Pressurizing heating roll, 20a to 20e ... Paper feeding tray, 22 ... Paper discharging tray,

Claims (2)

[Claims] 1. An image forming apparatus having the following requirements: (Y01) a latent image writing device for writing a latent image on the surface of an image carrier; (Y02) a toner for the latent image on the surface of the image carrier. A developing device for developing an image, (Y03) a transfer device which is arranged at a set transfer position along the surface of the image carrier and transfers a toner image on the surface of the image carrier onto a sheet passing through the transfer position (Y04) ) A sheet conveying device that takes out the sheet accommodated in the sheet feeding tray and sequentially conveys the sheet to the transfer position, the fixing position, and the discharge tray, (Y05) a fixing heating roll including a heater arranged at the fixing position, and A fixing device having a heating roll for pressurization, (Y06) set temperature storage means for storing the set temperature of the heating roll for fixing and the set temperature of the heating roll for pressurization, (Y07) one of the heating roll for fixing and the heating roll for pressing But Heat the heaters built in the fixing heating roll and the pressure heating roll so that the temperature reaches the set temperature earlier than the other by a predetermined time, and when the one roll reaches the set temperature, the one roll is heated to the one roll. A heating control device for stopping the heating of the built-in heater, (Y0
8) Image quality adjustment operation control means for starting the image quality adjustment operation at the same time as stopping the heating of the heater built in the one roll. 2. An image forming apparatus having the following requirements: (Y01) a latent image writing device for writing a latent image on the surface of an image carrier; (Y02) toner for the latent image on the surface of the image carrier. A developing device for developing an image, (Y03) a transfer device which is arranged at a set transfer position along the surface of the image carrier and transfers a toner image on the surface of the image carrier onto a sheet passing through the transfer position (Y04) ) A sheet conveying device that takes out the sheet accommodated in the sheet feeding tray and sequentially conveys the sheet to the transfer position, the fixing position, and the discharge tray, (Y05) a fixing heating roll including a heater arranged at the fixing position, and A fixing device having a heating roll for pressurization, (Y06) set temperature storage means for storing the set temperature of the heating roll for fixing and the set temperature of the heating roll for pressurization, (Y07) one of the heating roll for fixing and the heating roll for pressing But Heat the heaters built in the fixing heating roll and the pressure heating roll so that the temperature reaches the set temperature earlier than the other by a predetermined time, and when the one roll reaches the set temperature, the one roll is heated to the one roll. A heating control device for stopping the heating of the built-in heater, (Y0
9) Copy start command storage means (main CPU) that stores the input of the copy start switch when the copy start switch is input before the image quality adjustment operation is completed, (Y010) Image quality adjusting operation control means for starting the image quality adjusting operation at the same time as the two conditions that the heating of the built-in heater is stopped and that the copy start switch is input.