JP2003280488A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which can shorten a first print-out time as the time from the command of an image formation start signal to the completion of image formation upon occasion, and then realizing both of shortening the first print-out time and making the picture quality of an image high. <P>SOLUTION: A default mode wherein image formation is performed after ATVC as transfer preparing operation ends after the temperature of a fixing heater and the rotational frequency of a polygon mirror reach 99% of target values with a command of a print signal and a draft mode wherein image forming operation is carried out after ATVC made shorter than that in the default mode ends after the temperature of the fixing heater and the rotational frequency of the polygon mirror reach 90% of the target values with the command of the print signal, are so set that they can be switched, and the paper feed timing of a recording material is made earlier in the draft mode than in the default mode. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for recording an image on a recording material by a series of image forming processes.

[0002]

2. Description of the Related Art Conventionally, for example, a photosensitive drum as a latent image carrier capable of carrying a latent image, a charging roller as a charging means for charging the surface of the photosensitive drum to a predetermined potential,
An exposure device that is an exposure unit that forms a latent image on the photosensitive drum by performing an exposure process on the photosensitive drum after being charged by the charging roller according to image information, and the latent image formed by the exposure device. A developing device that is a developing unit that visualizes a toner image that is a developer image, a transfer roller that is a transfer unit that transfers the toner image from the photosensitive drum to the recording material as an unfixed image, and the unfixed image is fixed to the recording material. An image forming apparatus is known that includes a fixing device that serves as a fixing unit.

In such an image forming apparatus, a paper feeding roller, which is a paper feeding means, feeds the recording material toward the transfer position at the paper feeding timing after the instruction of the image forming start signal. After the timing, the image forming operation is performed by the transfer roller so that the toner image is transferred from the photosensitive drum to the recording material. Further, from the command of the image formation start signal to the start of the image forming operation, in order to stably obtain a good image, the photosensitive drum, the charging roller, the exposure device, the developing device, the transfer roller, the fixing device, etc. It is a preparation period during which a predetermined preparation operation is performed. Therefore, the image forming operation is performed after the preparatory operation is completed and the state of the image forming apparatus becomes a predetermined operable state.

By the way, as a fixing device of such an image forming apparatus, a contact heating system such as a heat roller system or a film heating system is widely used. In a fixing device adopting such a contact heating method, a heating element having a halogen lamp or a heating resistor is caused to generate heat by supplying electric power to heat a toner image on a recording material via a roller or a film. For example, as a film heating type fixing device, there is a method of heating a recording material through a thin film by heating a heating element having a pattern of resistance heating elements on a ceramic substrate, and JP-A-63-313182. Have been proposed.

In such a fixing device, for example,
If the electric power input to the fixing device is small, the weight of the recording material is large or the surface property of the recording material is poor, or if the ambient temperature of the image forming apparatus is extremely low,
There are cases in which the rate of temperature rise of the heating element of the fixing device decreases, which causes a delay in heating or a decrease in the temperature control temperature during fixing, resulting in a decrease in fixability. Therefore, in the past, in these cases, in order to compensate for the heating delay of the heating element of the fixing device or to set the temperature control temperature at the time of fixing to a high level, the paper feeding timing should be delayed. Control is set to extend the heating time of the heating element in the preparation period. As a result, even in the above case, it is possible to stably obtain a good image.

[0006]

However, in the conventional image forming apparatus as described above, the sheet feeding is performed so that the image forming operation is started after the state of the image forming apparatus reaches a predetermined operable state. The timing is set, and the toner image is not transferred from the photosensitive drum to the recording material until after this paper feeding timing.Therefore, the time from the command of the image formation start signal to the completion of image formation is the first printout time. (Hereinafter, abbreviated as FPOT) will be delayed.

Further, as described above, when the electric power input to the fixing device is small, the weighing amount of the recording material is large, or the surface property of the recording material is poor, the ambient temperature of the image forming apparatus is extremely low. In an image forming apparatus that employs a control for delaying the paper feed timing in some cases, the FPOT delay will be further increased.

Even when the user wants to prioritize the shortening of the FPOT over the image formation with a higher image quality than necessary, it is difficult to obtain high customer satisfaction if the FPOT delay is caused as described above.

Therefore, according to the present invention, the first printout time, which is the time from the command of the image formation start signal to the completion of the image formation, can be shortened as necessary, and the first printout time can be shortened and the image quality can be improved. An object of the present invention is to provide an image forming apparatus capable of achieving both high image quality.

[0010]

According to the present application, the above object is to provide a latent image carrier capable of carrying a latent image, charging means for charging the surface of the latent image carrier to a predetermined potential, and image information. According to the exposure means, the latent image carrier after being charged by the charging means is exposed to light to form a latent image on the latent image carrier, and the latent image formed by the exposure means is developed. An image provided with developing means for visualizing as a developer image, transfer means for transferring the developer image from the latent image carrier to a recording material as an unfixed image, and fixing means for fixing the unfixed image on the recording material. In the image forming apparatus, the image forming apparatus includes a sheet feeding unit that feeds the recording material toward the transfer position at a sheet feeding timing after the image forming start signal is instructed. The state becomes a prescribed operable state After that, the default mode in which the image forming operation is performed and the draft mode in which the image forming operation is performed before the state of the image forming apparatus reaches the predetermined operable state by the instruction of the image forming start signal are set to be switchable. The sheet feeding means is achieved by the first invention that the sheet feeding timing in the draft mode is earlier than the sheet feeding timing in the default mode.

According to the present application, in the first aspect of the present invention, the exposure means is such that the exposure start timing from the command of the image start signal in the draft mode is from the command of the image start signal in the default mode. It is also achieved by the second invention that the timing is earlier than the exposure start timing.

Further, according to the present application, in the first or second invention, the above-mentioned object is that the transfer means includes a transfer member arranged in contact with or in proximity to the latent image carrier and the latent image. The developer image on the latent image carrier is transferred to the recording material by applying a predetermined transfer bias between the carrier and the recording material, and transfer from the command of the image start signal in the draft mode. It is also achieved by the third invention that the bias application start timing is earlier than the transfer bias application start timing from the command of the image start signal in the default mode.

Further, according to the present application, in the above-mentioned object, in any one of the first to third inventions, the developing means is arranged in proximity to or in contact with the latent image carrier to carry a developer. By applying a predetermined developing bias between the developer carrier and the latent image carrier, the developer is applied to the latent image carrier to form a latent image on the latent image carrier as a developer image. The invention is also achieved by the fourth invention in which the development bias application start timing from the image start signal command in the draft mode is earlier than the development bias application start timing from the image start signal command in the default mode. .

According to the present application, the above-mentioned object is the charging means in any one of the first to fourth inventions.
The latent image carrier is charged to a predetermined potential by applying a predetermined charging bias between the latent image carrier and a charging member disposed in proximity to or in contact with the latent image carrier, and the draft mode. A fifth aspect of the present invention is that the charging bias application start timing from the image start signal command at time is earlier than the charging bias application start timing from the image start signal command at the default mode.

Further, according to the present invention, in the above-mentioned object, in any one of the first to fourth inventions, the paper feeding means is capable of image formation or image formation before feeding the recording material in the draft mode. The present invention can also be achieved by the sixth invention in which the paper feeding operation is possible after a notification is given regarding any of the weight, type, or thickness of a recording material that cannot be formed, or the product name.

Further, according to the present application, the above-mentioned object is in any one of the first invention to the sixth invention, the paper feeding means is
At least one state of weighing, type, or thickness of recording material, or product name is detected, and the default mode or draft mode is switched based on the detection result to determine the paper feed timing. It is also achieved by the seventh invention of being present.

According to the present application, the above-mentioned object is the fixing means in any one of the first invention to the seventh invention.
By fixing the unfixed image on the recording material by heating the recording material carrying the unfixed image at a predetermined fixing temperature control temperature,
Eighth, the heater input voltage from the image start signal command in the draft mode to the fixing temperature control temperature is different from the heater input voltage from the image start signal command in the default mode to the fixing temperature control temperature. It is also achieved by the invention of.

Further, according to the present application, the above-mentioned object is the fixing means in any one of the first invention to the seventh invention.
By fixing the unfixed image on the recording material by heating the recording material carrying the unfixed image at a predetermined fixing temperature control temperature,
In the draft mode, the heater input voltage from the image start signal command to the fixing temperature control temperature is higher or lower than the heater input voltage from the image start signal command to the fixing temperature control temperature in the default mode. It is also achieved by the nine inventions.

Further, according to the present application, in any one of the first to ninth inventions, the fixing means heats a recording material carrying an unfixed image at a predetermined fixing temperature control temperature. By doing so, the unfixed image is fixed on the recording material, and the temperature control temperature for fixing in the draft mode is higher or lower than the temperature control temperature for fixing in the default mode.

Further, according to the present application, the above-mentioned object is the fixing means in any one of the first to tenth inventions.
In the case of continuous image formation of multiple recording materials by heating the recording material with the heat from the heating element that is controlled at a predetermined temperature control temperature, fixing the succeeding recording material from the end of fixing the preceding recording material in draft mode According to the eleventh invention, the temperature-controlled temperature during the start is higher than the temperature-controlled temperature between the end of fixing the preceding recording material and the start of fixing the following recording material in the default mode. To be achieved.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) First, a first embodiment of the present invention will be described.

FIG. 1 is a sectional view showing a schematic configuration of the image forming apparatus of this embodiment.

In such an image forming apparatus, as shown in FIG. 1, around the photosensitive drum 1 which is a latent image carrier, a charging roller 2 which is a charging means and an exposure which is an exposing means are arranged in order along the rotation direction thereof. A device 3, a developing device 4 as a developing means, a transfer roller 5 as a transferring means, a cleaning device 6 and the like are arranged.

Further, in the lower part of the main body of the image forming apparatus,
A paper feed cassette 7 that stores a sheet-shaped recording material P such as paper is arranged. Along the conveyance path of the recording material P from the paper feed cassette 7, the paper feed roller 15, the conveyance roller 8, the top sensor 9, the transfer roller 5, the conveyance guide 10, the fixation guide, and the fixing means are arranged in order from the upstream side. The device 11, the transport roller 12, the paper discharge roller 13, the paper discharge tray 14, and the like are arranged.

Next, the operation of the image forming apparatus having the above structure will be described.

The photosensitive drum 1 is rotationally driven in the direction of arrow R1 by a driving means (not shown), and its surface is uniformly charged to a predetermined polarity and a predetermined potential by the charging roller 2. Then, the surface of the photosensitive drum 1 after being charged by the charging roller 2 is subjected to image exposure based on image information by an exposure device 3 such as a laser optical system, and charges in the exposed portion are removed to form an electrostatic latent image. It is formed.

The electrostatic latent image is developed by the developing device 4. The developing device 4 has a developing roller 4a,
By applying a developing bias between the developing roller 4a and the photosensitive drum 1, toner is attached to the electrostatic latent image on the photosensitive drum 1 to visualize the electrostatic latent image as a toner image. To do.

On the other hand, the recording material P is stored in the paper feed cassette 7, is fed and conveyed by the paper feed roller 15 and the conveyance roller 8, passes through the detection position of the top sensor 9,
The sheet is conveyed to the transfer nip portion between the photosensitive drum 1 and the transfer roller 5. At this time, the leading edge of the recording material P is detected by the top sensor 9, and the recording material P is synchronized with the toner image on the photosensitive drum 1.

The toner image is transferred onto the recording material P such as paper by the transfer roller 5. At this time, the top sensor 9
The application of a transfer bias between the photosensitive drum 1 and the transfer roller 5 is started by this signal, and the toner image on the photosensitive drum 1 is transferred onto the recording material P as an unfixed toner image.

Recording material P carrying the above-mentioned unfixed toner image
Is transported to the fixing device 11 along the transport guide 10,
Here, the unfixed toner image is heated and pressed to be fixed on the surface of the recording material P. The recording material P on which the toner image has been fixed is conveyed and discharged by the conveying roller 12 and the paper discharging roller 13 onto the paper discharging tray 14 on the upper surface of the image forming apparatus main body.

On the other hand, after the toner image is transferred onto the recording material P by the transfer roller 5, the toner remaining on the surface of the photosensitive drum 1 without being transferred onto the recording material P is removed by the cleaning blade 6a of the cleaning device 6. Prepare for the next image formation.

As described above, in such an image forming apparatus, it is possible to form images one after another by repeating the above operation.

In this embodiment, the transfer roller 5 is
An elastic layer (not shown) of conductive rubber or conductive sponge is formed on a core metal (not shown) such as SUS or Fe. This elastic layer is made of rubber having a high resistance to a medium resistance by adding a low resistance material such as carbon to 10 ⁶ -1.
The resistance is adjusted to 0 ¹⁰ Ω to become an electronic conductor.

A constant current value is maintained between the photosensitive drum 1 and the transfer roller 5 until the image information is written on the photosensitive drum 1 by the laser beam from the exposure device 3 or between the sheets. A constant current controlled bias is applied. Then, the voltage Vo generated in the transfer roller 5 during the constant current control is detected, and the transfer voltage Vt of the transfer bias is determined based on this Vo (Active transfer voltage control for determining such transfer voltage is performed). Contr
ol (hereinafter referred to as ATVC). A transfer bias whose constant voltage is controlled by the transfer voltage Vt is applied to the transfer roller 5. The reason for performing ATVC is that the resistance value in the circumferential direction of the transfer roller varies, and in the contact transfer method, the optimum voltage value to be applied changes depending on the resistance value of the transfer roller. This is to obtain appropriate transferability.

The fixing device 11 of this embodiment will be described with reference to FIG.

FIG. 2 shows a film heating type fixing device 11.
3 is a cross-sectional view showing the schematic configuration of FIG.

In the fixing device 11, as shown in FIG. 2A, an endless and heat-resistant film 102 is externally fitted to a heating body support 101 including a heating body 103 and is rotatably guided. ing. The inner peripheral length of the film 102 is formed to be, for example, about 3 mm larger than the outer peripheral length of the heating body supporting member 101. Therefore, the film 102 is loosely fitted to the heating body supporting body 101 with a sufficient peripheral length. There is.

The film 102 has a film thickness of 100 μm or less, preferably 50 μm or less and 20 μm in order to reduce the heat capacity and improve the quick start property.
Heat-resistant PTFE, PFA, FEP single layer,
Or polyimide, polyamide imide, PEEK, PE
It is possible to use a composite layer film in which the outer peripheral surface of S, PPS or the like is coated with PTFE, PFA, FEP or the like. In this embodiment, PTF is formed on the outer peripheral surface of the polyimide film.
E, coated with PFAE is used.

The heating element 103 is formed by coating an electrical resistance material such as Ag or Pd (silver and palladium) on the surface of a substrate made of alumina or the like by screen printing to have a thickness of about 10 μm and a width of 1 to 3 mm. Glass, fluororesin, or the like is coated thereon as a protective layer 107.

The pressure roller 104 is a rotating body that drives the film 102 by forming a nip N by being pressed by the heating body 103 via the film 102. The pressure roller 104 has a cored bar 104a and a heat-resistant rubber 104b having a good releasability such as silicon rubber, and is rotated by a driving means (not shown) connected to the axial end of the cored bar 104a. It is designed to be driven.

As shown in FIG. 2B, the output of the thermistor 105 provided on the heating element 103 is A / D converted and taken into the CPU 110. Based on this information, the CPU 1
10 drives the triac 111, and the electric power supplied to the heating element 103 is controlled by the phase of the AC voltage, the wave number control, etc., and is temperature-controlled so as to be maintained at a predetermined target temperature.

Next, the operation timing of each section in the image forming apparatus having the above-mentioned configuration will be described.

FIG. 3 is a timing chart showing the operation timing of each part of the image forming apparatus during normal printing (default mode described later).

As shown in FIG. 3, the image forming apparatus is instructed by an image forming start signal (hereinafter referred to as a print signal) (time A), and thereafter, heating of the heating element 103 of the fixing device 11 is started at the same time. The rotation of the polygon mirror (not shown) of the exposure device 3 is started.

When the heating condition of the heating element 103 of the fixing device 11 and the rotating condition of the polygon mirror of the exposure device 3 satisfy certain conditions (time B), the recording material P is fed from the paper feeding cassette 7 to the paper feeding roller. 15 is fed.

Laser exposure of the exposure device 3 is started at a timing after a predetermined time (time D) from when the top sensor 9 detects the leading end of the fed recording material P in the transport direction (time C-1). A latent image is formed on the photosensitive drum 1.

The latent image formed on the photosensitive drum 1 moves as the photosensitive drum 1 rotates and is visualized as a toner image by the developing device 4. After that, when the front end position of the toner image in the rotating direction of the photosensitive drum 1 reaches the transfer portion (time E-1), application of the transfer bias by the transfer roller 5 is started, and the transfer of the toner image to the recording material P is performed. Done.

Next, when the position of the recording material P corresponding to the leading end position of the toner image reaches the fixing device 11 (time F),
The toner image is transferred to the recording material P portion where the fixing process is started by the fixing device 11 and the toner image is transferred.
It is permanently fixed to the top.

After that, when the trailing edge of the recording material P in the conveying direction passes the detection position of the top sensor 9 (time C-2), the top sensor 9 no longer detects the recording material (time C).
-2).

When a plurality of recording materials are continuously printed on the recording material, a predetermined time elapses from the time when the trailing edge of the preceding recording material in the transport direction passes the top sensor 9 (time C-2). At a predetermined timing (time G), the succeeding recording material that follows the preceding recording material is fed by the feed roller 15 and the top sensor 9 detects the leading end in the transport direction (time C-3). Thus, the same processing as described above is performed. Hereinafter, the time between the time C-2 and the time C-3, or the distance between the preceding recording material and the following recording material is referred to as "paper interval".

In this example, the transfer bias is applied only when the recording material is passing through the transfer portion. Then, as soon as the recording material passes through the transfer portion and is no longer present in the transfer portion (time E-2), the transfer bias is set to be smaller than the voltage value and the current value at the time of transfer. This is because when a high bias such as a transfer bias is applied to the photosensitive drum 1 when the recording material is not present in the transfer portion, a phenomenon similar to the exposure occurs on the photosensitive drum 1 and the photosensitive drum 1 is exposed. This is because memory may be generated.

In this example, the charging bias application start timing (time G) and the developing bias application start timing (time H) must be before ATVC. Further, the charging bias and the developing bias must be finished before the top sensor 9 detects the recording material P (before the time C-1). Further, the developing bias (time H) needs to be applied later than the charging bias (time G). To briefly describe these time relationships, if the developing bias is applied at a timing earlier than the charging bias, an uncharged portion of the photosensitive drum 1, that is, an exposed state exists on the photosensitive drum 1. The developing bias must be applied after the charging bias because the portion is developed. Further, with respect to ATVC, it is possible to obtain better detection accuracy by performing measurement with the charging bias and the developing bias applied on the photosensitive drum 1. Although detailed description is omitted here, a mixed bias of an AC component and a DC component is used as the charging bias, and the charging bias mainly means the DC component. Also, AC component and D
The mixed bias of the C component is used, and the developing bias mainly means the DC component.

As described above, in the present embodiment, as shown in FIG. 3, the paper feed timing is determined by the time from the command of the print signal until the state of the image forming apparatus reaches a predetermined operable state. After the paper feed timing (time B), the toner image is transferred onto the recording material. That is, in the present embodiment, the time from the command of the print signal to the transfer of the toner image on the recording material is the time from the command of the print signal until the fixing device 11 and the exposure device 3 are in the ready state. It is determined by the time from the ready state to the completion of the ATVC operation of the transfer roller 5.

Therefore, in the present embodiment, an example in which the FPOT is shortened by shortening the time from the command of the print signal until the toner image as the unfixed image is formed on the recording material will be described. .

In this embodiment, a default mode in which the image forming operation is performed after the state of the image forming apparatus reaches the above-mentioned predetermined operable state by the command of the print signal,
It is set to be switchable between the draft mode in which the image forming operation is performed before the state of the image forming apparatus reaches the predetermined operable state by the command of the print signal.
Further, the paper feed roller 15 has the paper feed timing in the draft mode earlier than the paper feed timing in the default mode.

First, the default mode similar to the above-mentioned conventional example in the present embodiment will be described in detail with reference to FIG.

The conditions of the image forming apparatus of this embodiment are as follows: temperature 23 ° C., humidity 50%, power supply voltage 106V,
Power supply frequency 60 Hz, recording material basis weight 75 g / m ² (Xe
Rox Xx4024). Further, regarding the specifications of the image forming apparatus of the present embodiment, the number of image forming sheets per unit time is 14 sheets / minute, the maximum sheet passing size LTR size,
The process speed is 105 mm / sec, and the heater total resistance value of the heating element 103 of the fixing device 11 is 20Ω. Further, regarding the dimensions of the parts, the photosensitive drum 1 is φ30, the charging roller 2 is φ12, the developing roller 4a is φ16, and the transfer roller 5 is
Is φ14.5. A line extending from the rotation center of the photosensitive drum 1 to the rotation center of the transfer roller 5, the rotation center of the charging roller 2 from the rotation center of the photosensitive drum 1, the laser irradiation position on the photosensitive drum 1 by the exposure device 3, the rotation center of the charging roller 2. The angle formed by the lines
It is 60 ° and 185 °.

<Default Mode> (1) First, when image information is input to the image forming apparatus in the above-described state by a command of a print signal, the image information is expanded. At this time, in the case of a so-called host base in which image information is created by a host device such as a personal computer, the image information is expanded by the host device.

(2) After that, the rotation of the motor (not shown) in the image forming apparatus is started, and the rotational driving of the respective parts such as the transfer roller 5, the fixing film 102, the conveying rollers 8 and 12 is started. .

(3) The heating by the heating element 103 shown in FIG. 2 and the rotation of the polygon mirror (not shown) of the exposure apparatus 3 are started at substantially the same timing as the start of rotation of the motor.

(4) The heating element 103 is in a ready state (in this embodiment, the fixing device has reached a target temperature control temperature of 200 ° C. from room temperature), and the polygon mirror is in a ready state (99% of the target rotation speed). The first criterion is the time when the condition is reached. In the default mode, under the above conditions, in steps (1) to (4) "6.0
0 sec ”is required.

(5) Simultaneously with the first criterion, application of the AC component and DC component of the charging bias to the photosensitive drum 1 is started.

(6) From the above first criterion, 0.56se
After c, the DC component of the developing bias is applied. this is,
This is because, as described above, when a developing bias is applied to the surface portion of the photosensitive drum 1 which is not charged, it is developed by the toner. Therefore, the developing bias is applied to the surface portion of the photosensitive drum 1 after being charged.

(7) From the above first criterion, 0.81se
After c, ATVC of the transfer roller 5 is started. As described above, by applying the bias for the ATVC and performing the ATVC while the photosensitive drum 1 is at the predetermined charging potential and the developing potential, it is possible to control the transfer bias with high accuracy.

(8) The end of ATVC in (7) above is 2.83 seconds after the first criterion. This is AT
AT for four laps of the transfer roller 5 in order to improve the accuracy of VC
This is to secure time for performing VC.

(9) 1.80se from the above first criterion
The feeding of the recording material P is started after c. This is the recording material P
Considering the time from when the paper is fed to when it is conveyed and reaches the transfer site, the steps (1) to (8) are completed before the transfer site of the recording material is reached. The paper feed timing is delayed. In the present embodiment, the paper feed timing is such that the leading edge of the recording material P in the conveyance direction is the top sensor 9 at the timing when ATVC ends.
Is set to reach.

(10) From the first criterion above, 2.83s
After ec, the recording material P reaches the top sensor 9 (the timing at this time is the second criterion).

(11) 0.03s from the above second criterion
After ec, application of the AC component of the developing bias is started.
In this embodiment, the jumping developing method is adopted,
By applying this AC component, the photosensitive drum 1 is not for the first time.
It is possible to develop the latent image above. Further, based on the timing of starting the application of the AC component, the timing of the leading edge of the latent image on the photosensitive drum 1 and the timing of the leading edge of the recording material in the conveying direction are synchronized, and the exposure process on the photosensitive drum 1 is started. It

(12) 0.42 s from the above second criterion
The application of the transfer bias is started after ec. The application timing of the transfer bias is as described above for the photosensitive drum 1.
This is the timing when the leading edge of the upper toner image is synchronized with the leading edge of the recording material P in the conveying direction.

As described above, by the above steps (1) to (12), charging, development, and
By starting the application of each transfer bias, it becomes possible to form an image at an appropriate position on the recording material.

In this default mode, the time required from the command of the print signal to the arrival of the leading edge of the recording material P in the transport direction at the transfer site is (a) the command of the print signal to the polygon mirror of the exposure device 3 and the fixing device. By the time the 11 heating element 103 is ready, 6.00se
c, (b) 2.83 from the ready state until the leading end of the recording material P in the conveyance direction reaches the top sensor 9.
sec, (c) A total of 0.42 sec from when the leading edge of the recording material P in the transport direction reaches the top sensor 9 to when it reaches the transfer portion and the application of the transfer bias starts,
(A) + (b) + (c) = 9.25 sec.

After the front end of the recording material P in the conveying direction is conveyed from the transfer portion, the recording material P passes through the fixing portion and before the rear end of the recording material P in the conveying direction is ejected by the paper ejection roller 13. The required time (d) is 5.00 sec (L
TR size length: 279 mm).

Therefore, the time required from the start of the rotation of the motor by the command of the print signal to the start of the image forming process until the recording material is discharged, that is, F
The POT is 9.25 sec + (d) = 14.25 sec.

Next, the draft mode in this embodiment will be described in detail with reference to FIG. The conditions of the image forming apparatus are the same as in the draft mode described above.

FIG. 4 is a timing chart showing the operation timing of each part of the image forming apparatus in the draft mode.

<Draft Mode> (1) First, when image information is input to the image forming apparatus in the above-described state by a print signal command, the image information is expanded.

(2) After that, the rotation of the motor (not shown) in the image forming apparatus is started, and the rotational driving of the respective parts such as the transfer roller 5, the fixing film 102, the conveying rollers 8 and 12 is started. .

(3) The heating by the heating element 103 and the exposure device 3 are performed at almost the same timing as the start of rotation of the motor.
The rotation of the polygon mirror is started.

(4) The heating element 103 is in a ready state (in this embodiment, the fixing device has reached a target temperature controlled temperature of 200 ° C. from room temperature), and the polygon mirror is in a ready state (90% of the target rotational speed). The first criterion is the time when the condition is reached. In the draft mode, under the above conditions, the steps from (1) to (4) are "5.50."
sec ”is necessary.

(5) Simultaneously with the first criterion, application of the AC component and DC component of the charging bias to the photosensitive drum 1 is started.

(6) From the above first criterion, 0.56se
After c, the application of the DC component of the developing bias is started.

(7) From the above first criterion, 0.81se
After c, ATVC of the transfer roller 5 is started.

(8) The end of ATVC in (7) above is 1.30 seconds after the first criterion. This is AT
In order to maintain the accuracy of VC, A for one rotation of the transfer roller 5
This is to secure time for performing TVC.

(9) 0.27se from the above first criterion
The feeding of the recording material P is started after c.

(10) 1.30s from the above first criterion
After ec, the recording material P reaches the top sensor 9 (the timing at this time is the second criterion).

(11) From the above second criterion, 0.03 s
After ec, application of the AC component of the developing bias is started.

(12) 0.42 s from the above second criterion
The application of the transfer bias is started after ec.

As described above, by the steps (1) to (12) described above, charging, development, and
When the application of each transfer bias is started, the recording material P
It is possible to form an image at an appropriate position of.

In the draft mode of this embodiment, the time required from the command of the print signal to the arrival of the leading edge of the recording material P in the transport direction at the transfer site is (a) the command of the print signal to the polygon of the exposure device 3. By the time the mirror and the heating element 103 of the fixing device 11 are ready 5.
50 sec, (b) 1.30 sec until the leading edge of the recording material P in the transport direction reaches the top sensor 9 after the ready state, (c) the leading edge of the recording material P in the transport direction reaches the top sensor 9. From the time it reaches the transfer site to start applying the transfer bias, a total of 0.42 sec,
That is, (a) + (b) + (c) = 7.22 sec.

Therefore, the FPOT in the draft mode of this embodiment is 7.22 sec + (d) = 12.22.
It becomes sec.

Here, comparing the default mode and draft mode, the draft mode in step (4) and step (5) is 0.5 s in step (4).
ec, 1.53 sec time is shortened in step (5).

In step (4), the ready mode was not set to 99% in the default mode, but in the draft mode, 90% is the first criterion. The relationship between the rotation speed of the polygon mirror of the exposure apparatus 3 and the time is as shown in FIG. 5. In the default mode, the rotation speed of the polygon mirror after the start-up far exceeds the specified rotation speed and overshoots. Because of this, it took a long time to converge to the specified rotation speed. Further, in the default mode, the amount of current supplied to the coil for rotating the polygon mirror also remained constant at the time of startup, so it continues to be energized until it exceeds 99% of the specified rotation speed. there were. Therefore, when the draft mode in the present embodiment is selected, the first criterion is set to 90%, and the amount of current flowing to the coil is reduced at that time to prevent overshoot, and further to the specified rotation speed. The focusing time can be shortened.

On the other hand, in step (8), when the ATVC is performed in the default mode, the resistance value of the transfer roller is measured for four rounds in the circumferential direction, and the bias applied voltage is determined by the average value. . Regarding this voltage, no matter what environment the image forming apparatus is operated in, “piercing”, which is an image problem due to the drum memory caused by a strong transfer bias, or the toner holding force due to a weak transfer bias is generated. In order to prevent the phenomenon of "explosion", which is the scattering of toner due to the decrease and separation from the recording material, it is possible to control to apply the bias at the center value of the transfer bias that does not cause these phenomena. It was done. However, in the draft mode of the present embodiment, since the ATVC is performed only for one round of the transfer roller, it becomes impossible to apply the optimum transfer bias, but the “penetration” image, which is relatively unproblematic as an image problem, is slightly mitigated. A transfer bias of a voltage in the direction of applying is applied. In the present embodiment, control is performed to determine the applied voltage of the transfer bias by a value higher than the average value of the measured resistance value in the circumferential direction of the transfer roller for one rotation. This makes it possible to apply a relatively optimum transfer bias.

As described above, in the present embodiment, the FPOT in the default mode is 14.25 sec, the FPOT in the draft mode is 12.22 sec, and 2.0 in the draft mode than in the default mode.
FPOT is shortened for 3 seconds.

As described above, in this embodiment, the control of the rotational speed of the polygon mirror and each control of the ATVC are changed so that the condition for enabling the image forming operation is set to the condition before the predetermined operable condition in the default mode and the default condition. By setting the paper feed timing earlier than that in the mode, it is possible to shorten the FPOT. Also, by setting the paper feed timing earlier than in the default mode, charging, development,
It is possible to make the application start timing of each bias for transfer earlier than in the default mode. By making the application start timing of each bias earlier than in the default mode, a toner image is normally formed and the image quality is improved. Can be secured.

(Second Embodiment) Next, a second embodiment of the present invention will be described. The description of the same configuration as the first embodiment described above will be omitted.

Although it is possible to shorten the FPOT as described in the above first embodiment, if the time taken for the recording material to reach the transfer portion from the rotation of the motor is shortened, the recording material is transferred to the fixing device. The time it takes to get there is getting shorter. In the above-described first embodiment, the recording material enters the fixing device earlier than the 2.03 sec default mode.
Therefore, if fixing is performed in the draft mode without changing the control of the fixing device as it is in the default mode, the fixing device may be insufficiently warmed and a fixing failure may occur.

Therefore, in the present embodiment, when the draft mode is selected, each control relating to fixing is changed as described later to solve the above problem.

In the default mode, the target temperature control temperature is 200 ° C, the startup power is 90% of the input power, the offset power is 60% of the input power, and the fixing property is 10% (target fixing property is 15% or less, FoxR
iverBond 90 g / m ² ). Here, the fixing property refers to the rate of decrease in image density due to fixing.

However, in the first embodiment described above, when the draft mode (when nothing is changed regarding fixing) is selected, the target temperature adjustment temperature is 200 ° C. 90% of the startup power input power Offset power input power Since the fixing property at this time is 17 to 20% (target fixing property 15% or less, FoxRiverBond 90 g / m ² ), the fixing property is slightly worse than the default mode.

Therefore, as one of the methods for improving the fixability in the draft mode, the target temperature control temperature is 210 ° C., the startup power is 90% of the input power, the offset power is 60% of the input power, and the fixability at this time is 14% (target fixability). 15% or less, FoxR
iverBond 90 g / m ² ) and increasing the target controlled temperature makes it possible to secure the fixability of the first recording material.

However, even with this, the margin is small with respect to the target fixing property. Therefore, in the draft mode of the present embodiment, in order to further improve the fixing property, the target temperature adjustment temperature is 210 ° C. Offset power 60% of the input power The fixability at this time is 10-12% (target fixability 15% or less, FoxRiverBond 90g / m ² ).

As a result, in the present embodiment, it is possible to quickly reach the target temperature control temperature by increasing the target temperature control temperature and further increasing the input power when the target temperature control temperature is raised. It is possible to warm up.

The reason why the power at startup in the default mode is 90% is to prevent the temperature from overshooting after reaching the target controlled temperature. In this example, the reason why the startup power can be set to 100% is that there is a possibility that the above-mentioned overshoot may occur and some hot offset may occur at the tip portion, but the overall fixability is This is because the optimum value can be obtained. Further, as another method, the same effect can be obtained by increasing the offset power.

Next, although the fixing property of the first recording material can be secured by the above method, the fixing property of the second recording material continuously conveyed is also short because the FPOT is short. However, the fixability may be slightly poor. In the default mode, this is a target temperature-controlled temperature between sheets (hereinafter referred to as the target temperature between sheets) as a measure for raising the temperature of the non-sheet passing portion when a narrow recording material is passed through the fixing device. Occurs because the fixing device keeps warming up by the time the second recording material arrives.

In the default mode, the target controlled temperature between sheets is 190 ° C., and the fixing property of the second sheet at this time is 15% (target fixing property 15% or less, FoxRiverBond 90 g / m ² ).

In the first embodiment described above, when the draft mode (when nothing is changed regarding the paper interval) is selected, the target temperature control temperature is 190 ° C. and the fixability of the second sheet at this time is 17 to 20%. (Target fixability 1
Since it was 5% or less and FoxRiverBond 90 g / m ² ), the fixing property of the second and subsequent recording materials would be slightly deteriorated as it is.

Therefore, in the present embodiment, as a method for improving the fixability of the second and subsequent sheets in the draft mode, the paper-sheet target temperature control temperature 195 ° C. is the fixability of 15% (target fixability of 15% or less, FoxR
iverBond 90 g / m ² ).

As a result, in this embodiment, it is possible to secure the fixability of the second and subsequent recording materials by increasing the target controlled temperature between sheets.

In this embodiment, no particular measures are taken to raise the temperature of the non-sheet passing portion without any problem. The reason is that in the present embodiment, the target controlled temperature between sheets is set higher than that in the default mode between the first sheet and the second sheet of continuous sheet feeding, between the second sheet and the third sheet, This is performed only between each sheet between the third and fourth sheets and between the fourth and fifth sheets.The target sheet temperature control temperature after the fifth sheet is the same as the default sheet temperature control temperature. This is because If the target temperature-controlled temperature is increased only for the first to fifth sheets, the temperature rise in the non-sheet-passing area will deteriorate slightly, and the margin for abnormal temperature rise will decrease, which will cause the user to operate the device at all. No change (except for FPOT).

Therefore, according to the present embodiment, when the draft mode is selected, these values are controlled for the control of the target temperature control temperature of the fixing device, the target paper temperature control temperature, the startup power, the offset power, and the like. By changing the value in the default mode as described above, the FPOT can be shortened as in the first embodiment described above, and the fixability can be secured.

In the present embodiment, an example in which the target controlled temperature in the draft mode is set higher than that in the default mode has been described, but the type of recording material is limited to thin ones or those with good surface properties. This makes it possible to set the target controlled temperature in the draft mode lower than that in the default mode. By setting such a low target temperature control temperature, the rising time to the target temperature control temperature can be shortened and the FPOT can be shortened.

(Third Embodiment) Next, a third embodiment of the present invention will be described. Note that the description of the same configuration as the above-described first embodiment or second embodiment will be omitted.

In the present embodiment, an example will be described in which the types of recording materials on which images can be formed in the draft mode are limited and the types of recording materials can be automatically determined.

According to the second embodiment described above, it is possible to secure the fixability while shortening the FPOT, but there may be a case where the fixing is defective depending on the kind of the recording material.

Therefore, in the present embodiment, in order to form a normal image and to improve the fixing property, the type of recording material which can or cannot form an image is announced, so that the second embodiment can be used. It is possible to secure the fixability without separately providing the fixing control for the draft mode as described above in addition to the fixing control for the default mode.

The content of the above announcement is that when announcing a recording material capable of forming an image, it has a good fixing property, for example, "set a basis weight of 80 g / m ² or less".
And so on. On the other hand, when announcing a recording material that cannot form an image, for example, "Do not set a grammage of 80 g / m ² or more", or even if the surface of the recording material is poor Because of the influence, "Bond paper,
Do not load recycled paper. "

As a background of selecting these paper types,
Using the same image forming apparatus as in the first embodiment, the fixability was confirmed for various paper types. The results are shown in Table 1.
Shown in.

[0120]

[Table 1]

Table 1 shows examples of paper types, and basis weights, surface properties and fixing properties thereof.

As can be seen from Table 1, the basis weight is about 80.
When it is more than g / m ² , the fixability is not satisfactory, and it can be judged that the fixability is poor even on paper having poor surface properties. In addition, the surface property in Table 1 means that the standard is Xx4024, and the basis weight is 75 g /
and m ^2, the bad paper type of surface than the paper type is "×", the good surface properties of paper was evaluated as "○". What is fixability?
When the density decrease rate was 15% or more, it was marked as "x", and when the density decrease rate was 15% or less, it was marked as "O".

Next, a concrete method of the above announcement will be described.

When the draft mode is selected by the user, a screen as a paper type setting window as shown in FIG. 6A is displayed on the information display device (for example, monitor) of the user, and image formation is possible or impossible. Display and announce information on various recording materials. Further, as shown in FIG. 6B, it can be displayed in the printer setting information window for the image forming apparatus, or as shown in FIG. 6C, an image can be formed in the paper type setting portion of the setting information window. Only the types of recording materials that are available will be displayed and announced. By these announcements, the user selects a recording material or resets the recording material and shifts to the image forming start operation.

As another method of this announcement, there is also a method of announcing to the user the type of recording material capable of forming an image or not forming an image as a voice.

On the other hand, even if the draft mode is not selected by the user, it automatically shifts to the draft mode without bothering the user by automatically discriminating the type of the recording material set in the paper feed cassette or the like. Therefore, the FPOT can be shortened. If the type of recording material that is set cannot be used for image formation, a screen that is a paper type setting window is displayed on the user's information display device (for example, a monitor), and the set paper type is displayed. Information for prompting the change, displaying information for prompting a similar change in the printer setting information window for the image forming apparatus, and being set in the paper type setting section of the setting information window. The type of recording material is displayed, and information on paper types that can be used for image formation is displayed in a list for announcement. By these announcements, the user changes the recording material and shifts to the image forming start operation.

As a method of informing the information of the recording material capable of forming an image or incapable of forming an image, it is possible to use a voice in addition to the display on the screen as described above.
It is also possible to combine these notification methods.

Therefore, according to the present embodiment, the optimum recording material for fixing is selected by informing the information such as the type of recording material capable of forming an image or the type not capable of forming an image before the paper feeding timing. Since it can be fed,
In addition to the effect of the second embodiment described above, the fixing property is further improved, and a high quality image can be obtained. Further, since the information of the recording material is automatically discriminated, the default mode or the draft mode can be automatically selected, and the usability can be improved.

[0129]

As described above, according to the first invention of the present application, when the default mode is selected, the state of the image forming apparatus can be operated in a predetermined state by the instruction of the image forming start signal. When the image forming operation is performed after the state is reached and the draft mode is selected, the paper feeding unit feeds the recording material earlier than in the default mode, and the image forming apparatus is instructed by the image forming start signal. Since the image forming operation is performed before the state reaches the predetermined operable state, the first printout time, which is the time from the command of the image forming start signal to the image forming completion, is shortened as necessary. Therefore, it is possible to achieve both the reduction of the first printout time and the improvement of the image quality.

According to the second invention of the present application,
When the default mode is selected, the image forming operation is performed after the state of the image forming apparatus reaches a predetermined operable state by the command of the image formation start signal, and when the draft mode is selected, the sheet feeding operation is performed. The means feeds the recording material earlier than in the default mode, the exposure means starts the exposure processing earlier than in the default mode, and the state of the image forming apparatus can be in the predetermined operation by the instruction of the image formation start signal. Since the image forming operation is performed before the state is reached, it is necessary to shorten the first printout time, which is the time from the command of the image forming start signal to the completion of image forming, while ensuring the image quality. Therefore, it is possible to reduce the first printout time and achieve high image quality at the same time.

Further, according to the third invention of the present application, when the default mode is selected, the image is formed after the state of the image forming apparatus reaches a predetermined operable state by the instruction of the image forming start signal. When the forming operation is performed and the draft mode is selected, the sheet feeding unit feeds the recording material earlier than in the default mode, the transfer unit starts applying the transfer bias earlier than in the default mode,
Since the image forming operation is performed before the state of the image forming apparatus reaches the predetermined operable state by the instruction of the image forming start signal, the image forming is performed from the instruction of the image forming start signal while ensuring the image quality. The first print-out time, which is the time until completion, can be shortened as necessary, and both reduction of the first print-out time and high image quality can be achieved.

Further, according to the fourth invention of the present application, when the default mode is selected, the image is formed after the state of the image forming apparatus reaches a predetermined operable state by the instruction of the image forming start signal. When the forming operation is performed and the draft mode is selected, the sheet feeding unit feeds the recording material earlier than in the default mode, and the developing unit starts application of the developing bias earlier than in the default mode. Since the image forming operation is performed before the state of the image forming apparatus reaches the predetermined operable state by the instruction of the image forming start signal, the image forming is performed from the instruction of the image forming start signal while ensuring the image quality. The first printout time, which is the time until completion, can be shortened as necessary, and the first printout time can be shortened and the image quality can be improved. It is possible to achieve both.

According to the fifth invention of the present application,
When the default mode is selected, the image forming operation is performed after the state of the image forming apparatus reaches a predetermined operable state by the command of the image formation start signal, and when the draft mode is selected, the sheet feeding operation is performed. The means feeds the recording material earlier than in the default mode, the charging means starts charging bias application faster than in the default mode, and the state of the image forming apparatus is set to the predetermined operation by the instruction of the image forming start signal. Since the image forming operation is performed before the ready state is reached, the first printout time, which is the time from the command of the image forming start signal to the image forming completion, is shortened as necessary while ensuring the image quality. Therefore, it is possible to reduce the first printout time and achieve high image quality at the same time.

Further, according to the sixth invention of the present application, when the default mode is selected, the image is formed after the state of the image forming apparatus reaches a predetermined operable state by the instruction of the image forming start signal. When the forming operation is performed and the draft mode is selected, the sheet feeding unit notifies the weighing amount, the type, the thickness, or the product name of the recording material that can or cannot form an image. After that, the recording material is fed earlier than in the default mode, and the image forming operation is performed before the state of the image forming apparatus reaches the predetermined operable state by the instruction of the image forming start signal. The first printout time, which is the time from the command of the image formation start signal to the completion of image formation, can be shortened as necessary while securing the fixing property. It is possible to achieve both of the high image quality of the shortening and image strike printout time.

According to the seventh invention of the present application,
At least one state of weighing, type, or thickness of recording material, or product name is detected, and the default mode or draft mode is switched based on the detection result, and when the default mode is selected, the image is displayed. When the image forming operation is performed after the state of the image forming apparatus reaches a predetermined operable state by the command of the formation start signal and the draft mode is selected, the sheet feeding unit causes the recording material to move faster than in the default mode. The image forming operation is performed before the state of the image forming apparatus reaches the above-mentioned predetermined operable state by feeding an image forming start signal to the image forming apparatus. It is possible to shorten the first printout time, which is the time from the start signal command to the completion of image formation, if necessary. It is possible to achieve both of the high image quality of the shortening and images § over strike printout time.

According to the eighth invention of the present application,
When the default mode is selected, the image forming operation is performed after the state of the image forming apparatus reaches a predetermined operable state by the instruction of the image formation start signal, and when the draft mode is selected, the fixing unit is selected. Causes the heating element to be heated to the fixing control temperature with a power different from that in the default mode, the paper feeding unit feeds the recording material earlier than in the default mode, and the image forming apparatus is instructed by the image forming start signal. Since the image forming operation is performed before the state reaches the predetermined operable state, the first printout time which is the time from the command of the image forming start signal to the completion of image forming while securing the fixing property. Can be shortened as required, and both the shortening of the first printout time and the improvement in image quality can be achieved.

According to the ninth invention of the present application,
When the default mode is selected, the image forming operation is performed after the state of the image forming apparatus reaches a predetermined operable state by the instruction of the image formation start signal, and when the draft mode is selected, the fixing unit is selected. Is to heat the heating element to the fixing control temperature with more or less electric power than in the default mode, the paper feeding unit feeds the recording material earlier than in the default mode, and the image forming start signal instructs the image formation. Since the image forming operation is performed before the state of the forming apparatus reaches the predetermined operable state,
The first printout time, which is the time from the command of the image formation start signal to the completion of image formation, can be shortened as necessary while securing the fixing property. It is possible to achieve both.

Further, according to the tenth invention of the present application, when the default mode is selected, the image is formed after the state of the image forming apparatus reaches a predetermined operable state by the instruction of the image forming start signal. When the forming operation is performed and the draft mode is selected, the sheet feeding unit feeds the recording material earlier than in the default mode, and the state of the image forming apparatus is set to the predetermined operation by the instruction of the image forming start signal. The image forming operation is performed before the ready state is reached, and the fixing unit is
Since the fixing temperature is higher or lower than that in the default mode, the first printout time, which is the time from the image formation start signal command to the image formation completion, is required while securing the fixing property. Accordingly, it is possible to reduce both the first printout time and the high image quality at the same time.

According to the eleventh invention of the present application, when the default mode is selected, after the state of the image forming apparatus reaches a predetermined operable state by the instruction of the image forming start signal. When the image forming operation is performed and the draft mode is selected, the paper feeding unit feeds the recording material earlier than in the default mode, and the state of the image forming apparatus is set to the predetermined state by the instruction of the image forming start signal. When the image forming operation is performed before reaching the operable state, and in the case of continuous image formation of a plurality of recording materials, the temperature control between the sheets from the end of fixing of the preceding recording material to the start of fixing of the succeeding recording material. Since the temperature is higher than in the default mode, the first printout time, which is the time from the command of the image formation start signal to the completion of image formation, can be shortened as necessary while securing the fixability. Can be, it is possible to achieve both high image quality of the shortening and the image of the first print out time.

[Brief description of drawings]

FIG. 1 is a sectional view showing a schematic configuration of an image forming apparatus according to a first embodiment of the present invention.

2 is a sectional view showing a schematic configuration of a fixing device provided in the image forming apparatus of FIG.

FIG. 3 is a timing chart for explaining the operation of each part of the image forming apparatus in the default mode according to the first embodiment of the present invention.

FIG. 4 is a timing chart for explaining the operation of each part of the image forming apparatus in the draft mode according to the first embodiment of the present invention.

FIG. 5 is a diagram showing a relationship between the number of revolutions of a polygon mirror provided in the exposure unit and time according to the first embodiment of the present invention.

FIG. 6 is a diagram showing an example of a method of informing a recording material capable of forming an image or incapable of forming an image according to a third embodiment of the present invention.

[Explanation of symbols]

1 Photosensitive drum (latent image carrier) 2 Charging roller (charging member) 3 Exposure device (exposure means) 4 Developing device (developing means) 4a Developing roller (developer carrier) 5 Transfer roller (transfer member) 11 Fixing device (fixing means) 15 Paper feed roller (paper feed means) 103 heating body P recording material

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H027 DA21 DA38 DC04 DC05 DE07                       DE09 EC06 ED03 ED04 ED09                       ED17 ED24 ED25 EE02 EF06                       FA25 FA35 FB14 FB15 FB19

Claims (11)

[Claims] 1. A latent image carrier capable of carrying a latent image, a charging unit for charging the surface of the latent image carrier to a predetermined potential, and the latent image carrier after being charged by the charging unit according to image information. Exposure means for forming a latent image on the latent image carrier by exposing the body to light; developing means for visualizing the latent image formed by the exposure means as a developer image;
An image forming apparatus comprising: a transfer unit that transfers the developer image from the latent image carrier to a recording material as an unfixed image; and a fixing unit that fixes the unfixed image to the recording material. In an image forming apparatus including a sheet feeding unit that feeds a recording material toward a transfer position at a sheet feeding timing after a command of a signal, the state of the image forming apparatus reaches a predetermined operable state by an instruction of an image forming start signal. After that, the default mode in which the image forming operation is performed and the draft mode in which the image forming operation is performed before the state of the image forming apparatus reaches the predetermined operable state by the instruction of the image forming start signal are set to be switchable. The image forming apparatus is characterized in that the paper feeding means has a paper feeding timing in the draft mode earlier than a paper feeding timing in the default mode. 2. The exposure means is such that the exposure start timing from the image start signal command in the draft mode is earlier than the exposure start timing from the image start signal command in the default mode.
The image forming apparatus according to item 1. 3. The transfer means applies a predetermined transfer bias via a recording material between a transfer member arranged in contact with or close to the latent image carrier and the latent image carrier. The developer image on the latent image carrier is transferred to the recording material, and the transfer bias application start timing from the image start signal command in the draft mode is the transfer bias application start timing from the image start signal command in the default mode. The image forming apparatus according to claim 1, wherein the image forming apparatus is faster than the image forming apparatus. 4. The developing means applies a predetermined developing bias between the latent image bearing member and a developer bearing member which is disposed close to or in contact with the latent image bearing member and holds the developer. A developer is applied to the latent image carrier to make the latent image on the latent image carrier a developer image, and the development bias application start timing from the command of the image start signal in the draft mode is the image start in the default mode. The image forming apparatus according to any one of claims 1 to 3, wherein the development bias application start timing is earlier than a signal command. 5. The latent image carrier is charged by applying a predetermined charging bias between the latent image carrier and a charging member arranged in proximity to or in contact with the latent image carrier. It is charged to a predetermined potential, and the charging bias application start timing from the image start signal command in the draft mode is earlier than the charging bias application start timing from the image start signal command in the default mode. The image forming apparatus according to any one of claims 1 to 4. 6. The paper feeding means, in the draft mode, weighs, types, and
Alternatively, the image forming apparatus according to any one of claims 1 to 5, wherein the sheet feeding operation is possible after the notification of either the thickness or the product name is made. 7. The paper feeding means detects the state of at least one of weighing, type, or thickness of a recording material, or a product name, and the default mode or draft mode is switched based on the detection result. The image forming apparatus according to any one of claims 1 to 6, wherein the paper timing is determined. 8. The fixing unit fixes the unfixed image on the recording material by heating the recording material carrying the unfixed image at a predetermined fixing temperature control temperature by supplying electric power, and starts the image in the draft mode. The supply power from the command of the signal to the fixing controlled temperature is different from the supply power from the command of the image start signal in the default mode to the fixing controlled temperature. The image forming apparatus according to any one of claims. 9. The fixing means fixes the unfixed image on the recording material by heating the recording material carrying the unfixed image at a predetermined fixing temperature control temperature by supplying electric power, and starts the image in the draft mode. 8. The supply power from the command of the signal to reaching the fixing controlled temperature is more or less than the supply power from the command of the image start signal to the fixing controlled temperature in the default mode. The image forming apparatus according to claim 1. 10. The fixing means fixes the unfixed image on the recording material by heating the recording material carrying the unfixed image at a predetermined fixing temperature control temperature, and the fixing temperature control temperature in the draft mode is The image forming apparatus according to claim 1, wherein the temperature is higher or lower than the fixing temperature control temperature in the default mode. 11. The fixing unit heats a recording material by heat from a heating body whose temperature is controlled at a predetermined temperature, and in the case of continuous image formation of a plurality of recording materials, the preceding recording material in the draft mode is used. The temperature controlled temperature from the end of fixing to the start of fixing of the trailing recording material is higher than the temperature controlled temperature from the end of fixing of the preceding recording material to the start of fixing of the trailing recording material in the default mode. The image forming apparatus according to claim 1, further comprising: