JP4574176B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, such as a printer, a copier, or a facsimile, that controls the potential of a photoreceptor surface before image formation.

Conventionally, when an image forming apparatus such as a printer, a copying machine, or a facsimile machine is started up, as shown in FIG. 5A, the fixing device warms up (time from starting to reaching the fixing target temperature) in units of minutes. It took time. In particular, in a high-speed, high-quality image forming apparatus, the time required for warming up the fixing device tends to be long. Using the warm-up time, as shown in FIG. 5B, control around the photoreceptor, for example, adjustment of the non-exposure portion target potential by the charging device, adjustment of the exposure portion target potential by the exposure device, etc. It was.

  However, in recent years, due to the improvement in performance of the fixing device, as shown in FIGS. 6A and 6B, as shown in FIGS. It has become possible to

  In addition, with regard to the charging device and the exposure device, the performance of the image carrier, the power supply of the charging device, and the exposure device is improved as compared with the conventional one, and even if it is not controlled, it is usually used for characters and line drawings. Has become possible to output images with no problem level.

  In conventional control, for example, as disclosed in Patent Document 1, adjustment is generally made so that the charging potential becomes a predetermined value, and then adjustment is made so that the exposure amount becomes a predetermined value. In many cases, control is performed immediately after warm-up, in which temperature and the like are likely to change.

JP-A-6-230642

  It is desirable for a user who uses the image forming apparatus to be able to output an image simultaneously with activation. However, as shown in FIG. 6, although the warm-up time of the fixing device is shortened, it takes time to control the periphery of the photoconductor. The current situation is that the control of the surroundings is restricted and the shortening of the warm-up time of the fixing device is not effectively utilized.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that can shorten the time from when a user activates the image forming apparatus until an output image can be obtained.

According to a first aspect of the present invention, there is provided a photosensitive member, a charging unit that charges the surface of the photosensitive member, an exposure unit that exposes the charged surface of the photosensitive member to form an electrostatic latent image, and the electrostatic latent image. Developing means for developing the toner image with toner, heating means for heating and fixing the toner image onto a transfer material onto which the toner image formed on the photosensitive member has been transferred, potential detecting means for detecting the surface potential of the photosensitive member, A control unit that executes an adjustment process for adjusting the image formation condition based on a detection value of the potential detection unit ; and a memory that stores the image formation condition that is sequentially set in the adjustment process . The adjustment step is executed in parallel with the warm-up for causing the heating unit to reach the fixing target temperature, and the image output signal is received and the warm-up of the heating unit is completed before the adjustment step is completed. Case , The addition to interrupt the adjustment process, the start the image formation in the warm-up completion of the heating means in the image forming condition stored in the memory, continues the adjustment process described above interrupted after completion of the image formation performed It is characterized by.

According to a second aspect of the present invention, there is provided a photosensitive member, a charging unit that charges the surface of the photosensitive member, an exposure unit that exposes the charged surface of the photosensitive member to form an electrostatic latent image, and the electrostatic latent image. Developing means for forming a toner image by developing the toner, heating means for heating and fixing the toner image onto a transfer material onto which the toner image formed on the photosensitive member is transferred, and potential detection for detecting the surface potential of the photosensitive member And a control means for executing an adjustment process for adjusting the image forming conditions based on a detection value of the potential detection means, and a memory for storing the image forming conditions sequentially set in the adjustment process, The control means executes the adjustment step in parallel with the warm-up for causing the heating means to reach the fixing target temperature. Before the adjustment step is completed, the control means receives an image output signal and the warm-up of the heating means Completed If you are, before completion of the adjustment step, the start of the image formed by the image forming condition stored in the memory in the warm-up completion of the heating means, formed the adjusting step on the photosensitive member This is characterized in that it is continuously executed in a non-image area between the image areas.

According to a third aspect of the present invention, there is provided a photosensitive member, a charging unit that charges the surface of the photosensitive member, an exposure unit that exposes the charged surface of the photosensitive member to form an electrostatic latent image, and the electrostatic latent image. A developing means for developing the toner image with toner, a heating means for heating and fixing the toner image onto a transfer material onto which the toner image formed on the photoconductor is transferred, and a loading amount detecting means for detecting the toner loading amount of the toner image. And a control means for executing an adjustment process for adjusting the image forming condition based on a detection value of the above-described detection amount detecting means, and a memory for storing the image forming conditions sequentially set in the adjustment process, The means executes the adjustment step in parallel with the warm-up for causing the heating means to reach the fixing target temperature, and receives the image output signal and completes the warm-up of the heating means before the adjustment step is completed. Shi If you are, the with interrupting the adjustment process, the start the image formation in the warm-up completion of the heating means in the image forming condition stored in the memory, it continues the adjustment process described above interrupted after completion of image formation It is characterized by being executed.

According to a fourth aspect of the present invention, there is provided a photosensitive member, a charging unit for charging the surface of the photosensitive member, an exposure unit for exposing the charged surface of the photosensitive member to form an electrostatic latent image, and the electrostatic latent image. A developing means for developing the toner image with toner, a heating means for heating and fixing the toner image onto a transfer material onto which the toner image formed on the photoconductor is transferred, and a loading amount detecting means for detecting the toner loading amount of the toner image. And a control means for executing an adjustment process for adjusting the image forming condition based on a detection value of the above-described detection amount detecting means, and a memory for storing the image forming conditions sequentially set in the adjustment process, The means executes the adjustment step in parallel with the warm-up for causing the heating means to reach the fixing target temperature, and receives the image output signal and completes the warm-up of the heating means before the adjustment step is completed. Shi If you are, before completion of the adjustment step, the start of the image formed by the image forming condition stored in the memory in the warm-up completion of the heating means, formed the adjusting step on the photosensitive member This is characterized in that it is continuously executed in a non-image area between the image areas.

According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the warm-up of the heating unit is completed, and the adjustment process is not completed. It is characterized by comprising display means for displaying that it can be formed .

According to the present invention, since the image formation is started before the adjustment process for adjusting the image formation conditions is completed, the time until the start of the image formation is shortened accordingly, and the waiting time is shortened.

Hereinafter, embodiments and reference examples of the present invention will be described with reference to the drawings. In addition, what attached | subjected the same code | symbol in each drawing has the same structure or effect | action, The duplication description about these was abbreviate | omitted suitably.

< Reference example >
FIG. 1 shows an image forming apparatus according to the present embodiment and a reference example as an example of the image forming apparatus according to the present invention. The image forming apparatus shown in the figure is an electrophotographic image forming apparatus, and the figure is a longitudinal sectional view schematically showing a schematic configuration of a main part thereof.

  The image forming apparatus shown in FIG. 1 includes a drum-type electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) 1 as an image carrier. The photosensitive drum 1 is supported by an image forming apparatus main body (not shown) so as to be rotatable in the arrow R1 direction.

Around the photosensitive drum 1, a primary charger (charging means) 2, an exposure device (exposure means) 3, a potential sensor (potential detection means) 9, and a developing device (developing means) 4 are arranged almost in order along the rotation direction. , A toner application amount sensor (application amount detection means) 13, a transfer charger (transfer means) 5, a separation charger (separation means) 6, a cleaning device (cleaning means) 7, and a pre-exposure device (pre-exposure means) 8. It is installed. Further, the heating having the fixing roller 11 and the pressure roller on the downstream side of the separation charger 6b along the conveyance direction (arrow K direction) of the transfer material P (for example, sheet-like paper, transparent film). A fixing device 10 as a means is disposed. Further, an environmental sensor (not shown) for detecting temperature and humidity is disposed in the image forming apparatus main body. A charger power supply 15 controlled by a printer controller (control means) 14 is connected to the primary charger 2 described above. The printer controller 14 is connected to the exposure device 3, the potential sensor 9, the developing device 4, and the toner application amount sensor 13, and each operation is controlled. The printer controller 14 has a memory (storage means) 16 for storing the set value (charge amount) of the primary charger 2 and the set value (exposure amount) of the exposure device 3.

  In the image forming apparatus described above, at the time of image formation, the photosensitive drum 1 is rotationally driven at a predetermined process speed (circumferential speed) in the direction of the arrow R1 by a driving unit (not shown).

  The surface of the photosensitive drum 1 is uniformly (uniformly) charged to a predetermined polarity and potential by the primary charger 2. The surface of the photosensitive drum 1 after charging is irradiated with laser light that is controlled to be turned on / off based on image information by the exposure device 3, and the charge of the irradiated portion is removed to form an electrostatic latent image. The electrostatic latent image is developed as a toner image by the developing device 4 with toner attached at the developing portion D. As the developer, for example, a non-magnetic one-component developer can be used.

  The toner image thus formed on the photosensitive drum 1 reaches the transfer portion T between the photosensitive drum 1 and the transfer charger 5 by rotating the photosensitive drum 1 in the direction of arrow R1. The transfer material P is supplied to the transfer portion T so as to match the timing of the toner image. On the supplied transfer material P, the toner image on the photosensitive drum 1 is transferred by an electrostatic force generated between the photosensitive drum 1 and the transfer charger 5 by the transfer charger 5 to which a transfer bias having a polarity opposite to that of the toner image is applied. Transcribed.

  The transfer material P after the toner image is transferred is separated from the photosensitive drum 1 by the separation charger 6 to which a separation bias is applied and is conveyed to the fixing device 10. The transfer material P conveyed to the fixing device 10 is heated and pressurized when passing between the fixing roller 11 and the pressure roller 12 to fix the toner image on the surface, and is discharged outside the image forming apparatus. The

  On the other hand, after the toner image is transferred, the toner (transfer residual toner) remaining on the surface without being transferred to the transfer material P at the time of transfer described above is removed by the cleaning device 7 and the charge remaining on the surface is pre-exposed. It is removed by the vessel 8 and used for the next image formation.

  FIG. 2 is a flowchart showing a flow until image formation is started in the above-described image forming apparatus. 3A shows the change in temperature of the fixing roller 11 at that time, and FIG. 3B shows the photosensitive member potential (surface potential of the photosensitive drum 1).

When the image forming apparatus main body in the sleep mode (S1) returns from the sleep mode (for example, returns from the off mode, the sleep mode, or the energy saving mode by turning on the main switch or the soft switch) by a user operation or the like (S2). The printer controller 14 checks whether the main body of the image forming apparatus is normal, displays “print reservation is possible in fast mode” on the operation panel 17 (see FIG. 1) as display means (S3), and the fixing device 10 ( The warming-up ( see FIG. 1) and the adjustment process for adjusting other image forming conditions including potential control are started (S4). Here, the “fast mode” refers to a mode in which image formation is started after completion of warm-up (fixing warm-up ) of the fixing device 10 and before potential control.

Then, when the warm-up of the fixing device 10 other than the potential control is completed (S5), “printable in fast mode” is displayed (S6). This “printing is possible in the fast mode” is displayed until the potential control (adjustment process) is completed after the fixing warm-up is completed. When the potential control is completed, the display changes to “printing is possible in the normal mode”.

  Here, the potential control of the photosensitive drum 1 will be specifically described with reference to FIG. First, rotation of the photosensitive drum 1 is started and the pre-exposure unit 8 is turned on. The printer controller 14 sets the laser non-exposed portion potential and the exposed portion potential from the temperature, humidity, image mode, and the like. For example, the temperature detected by the environmental sensor is 23 ° C., the humidity is 50%, and the laser non-exposed portion potential is set to −600 V and the exposed portion potential is set to −100 V from the setting of the copy mode. The charge amount (current value) of the primary charger 2 was set to −1000 μA while confirming the potential of the photosensitive drum 1 with the potential sensor 9 so that the set non-exposed portion potential was −600V. Next, exposure is started while charging under the adjusted primary charging condition so that the exposure portion potential becomes −100 V, and the exposure amount is set to 120 while confirming the potential of the photosensitive drum 1 with the potential sensor 9 in the same manner as the primary charging. (Digital value).

  Although only a specific mode has been described here, depending on the setting of the image forming apparatus main body, the adjustment of the charge amount of the primary charger 2 and the adjustment of the exposure amount of the exposure device 3 may be performed for each mode (for example, copy mode, The charging amount and the exposure amount for each mode may be stored. Further, instead of setting the potential according to the temperature and humidity, the mode, etc., the primary charge and the exposure amount may be set while observing the toner amount on the photosensitive drum 1 by the toner amount sensor 13.

As described above, by setting each condition (adjusting the image forming condition) while directly confirming the potential of the photosensitive drum 1 or the amount of applied toner in each mode, it is possible to reproduce the target image quality.

  Returning to the flowchart of FIG.

  When the user issues an image output instruction (when an image output signal is input) while the “print reservation is possible in the fast mode” display (S3) before the fixing warm-up is completed (S5), that is, the user is in the fast mode. When the print reservation is made (Yes in S7), the printer controller 14 receives the instruction, and completes the fixing warm-up (S5), interrupts the potential control, and determines the charge amount of the primary charger 2 and the exposure device 3. The exposure amount is set to a backup value (S8), and image formation is started (S9).

  In addition, when the user instructs image output during the “printable in fast mode” display before the potential control is completed, that is, when the “printable in fast mode” display (S6) is displayed, the user still has If no print reservation is made (No in S7) and the user instructs printing while the potential control is continuing (S10) (S11), the potential control completion “printing in normal mode” is displayed at this point. When there is no image (No in S12), the printer controller 14 receives the instruction, interrupts the potential control, sets the charge amount of the primary charger 2 and the exposure amount of the exposure device 3 to backup values (S8), and the image. Formation is started (S9). On the other hand, when the user in step S11 instructs printing, if the potential control completion “printing in normal mode” is already displayed (Yes in S12), the printer controller 14 that has received the instruction performs primary charging. The charge amount of the device 2 and the exposure amount of the exposure device 3 are set to values obtained from the completed potential control (S13), and image formation is started (S9).

As described above, if the fixing warm-up has been completed, even if the control (adjustment process) for the charge amount of the primary charger 2 and the exposure amount of the exposure device 3 has not been completed, printing in the fast mode is performed. Execute. In other words, the image formation with the expected setting for the charge amount and the exposure amount is somewhat less reproducible than when the control is completely completed, but the user does not have to wait for the control to end without waiting for the control to end. Actual image formation can be started in a short time after the forming apparatus main body is activated.

< Embodiment >
This embodiment than Example, is capable to close the photoreceptor potential or toner amount to the target value to obtain an image close to the desired image quality.

The process until the user is informed that “printing is possible in the fast mode” is the same as in FIG. 2 of the reference example described above.

  FIGS. 4A and 4B show a change in the temperature of the fixing roller 11 (see FIG. 1) and a change in the photoreceptor potential in the present embodiment, respectively.

  It is assumed that the user instructs printing before the potential control is completed. The timing was during adjustment of the setting of the primary charger 2, and the exposure amount of the exposure apparatus 3 was not yet controlled. Therefore, the printer controller 14 sets the value −1050 μA last used for controlling the output value of the primary charger 2 and the average value −975 μA of the backup value −900 μA stored in the memory 16 of the printer controller 14 in advance. The exposure amount was calculated using the original value of the backup and the set value of the primary charger 2 and set from 100 × (−975 / −900) to 108V. At this time, the non-exposed portion potential was −590 V, and the exposed portion potential was −115 V.

After setting, start image output. In this embodiment, an IAE (image area exposure) method in which toner is placed on the exposure unit is used. Therefore, a non-image area corresponding to a space between the transfer material (image area) and the transfer material (image area) on the surface of the photosensitive drum 1, that is, a so-called paper gap, has the same non-exposed portion potential as the blank portion. By performing the potential control of the non-exposed portion potential between the sheets, the output value of the primary charger 2 can be set to −1000 μA, which is the same as when it is controlled. The exposure amount was changed by calculation from the non-exposure portion potential obtained during sequential image output, and was set from 100 × (−1000 / −900) to 111 when the control of the primary charger 2 was completed. At this time, the non-exposed portion potential was −600 V, and the exposed portion potential was −105 V.

  After the image output is completed, the exposure amount is reset to 120 by performing the potential control of the exposure unit that has not been controlled as usual. As a result, the non-exposed portion potential is −600 V and the exposed portion potential is −100 V, which can be perfectly matched with the target potential, and a desired image quality can be obtained at the next image output time.

By controlling as above, Oite to the present embodiment is not perfect, it is possible to perform image output image quality close to the further target picture quality than the reference example described above. Further, since the image is output in accordance with the target potential from the next image formation, it is possible to provide the user with an output image with good image quality.

In the above embodiments and reference examples , the toner application amount sensor 13 detects the toner application amount on the photosensitive drum 1. Instead, the toner application amount sensor 13 on the transfer material P after being transferred to the transfer material P is used. The amount of applied toner may be detected. Further, the case where the present invention is applied to a single-color image forming apparatus has been described above as an example. However, the present invention can be replaced with an image forming apparatus that forms a multi-color image (for example, a full-color four-color image). The present invention can be similarly applied to an image forming apparatus. In this case, unlike the above-described embodiments and reference examples , the toner image formed on the photosensitive drum is temporarily transferred to an intermediate transfer member (for example, an intermediate transfer belt or an intermediate transfer drum) and then transferred onto the intermediate transfer member. When the configuration in which the toner image is secondarily transferred to the transfer material is employed, the toner application amount sensor may detect the toner application amount of the toner image on the intermediate transfer member.

1 is a diagram schematically showing a schematic configuration of an image forming apparatus according to the present invention. It is a flowchart which shows the flow of control of this invention. FIG. 6 is a diagram illustrating transition of a fixing roller temperature and a photoreceptor potential in a reference example . Definitive to the embodiment, a diagram showing changes in temperature and the photosensitive member potential of the fixing roller. It is a figure which shows transition of the temperature of a conventional fixing roller, and a photoreceptor potential. It is a figure which shows transition of the temperature of a fixing roller in recent years, and a photoreceptor potential.

Explanation of symbols

1 Photoconductor (Photosensitive drum)
2 Charging means (primary charger)
3 Exposure means (exposure equipment)
4 Development means (developing device)
9 Potential detection means (potential sensor)
13 Amount-of-load detection means (toner amount sensor)
14 Control means (printer controller)
16 Storage means (memory)
P transfer material

Claims (5)

A photoreceptor,
Charging means for charging the surface of the photoreceptor;
Exposure means for exposing the surface of the photoreceptor after charging to form an electrostatic latent image;
Developing means for developing the electrostatic latent image with toner;
Heating means for heating and fixing the toner image on a transfer material onto which the toner image formed on the photosensitive member is transferred;
A potential detecting means for detecting a surface potential of the photoreceptor;
Control means for executing an adjustment process for adjusting image forming conditions based on the detection value of the potential detection means;
A memory for storing image formation conditions sequentially set in the adjustment step ,
The control means executes the adjustment step in parallel with the warm-up for causing the heating means to reach the fixing target temperature, receives an image output signal before the adjustment step is completed, and warms up the heating means. Is completed, the adjustment process is interrupted , and image formation is started under the image formation conditions stored in the memory at the time when the heating means is warmed up . Continue the adjustment process,
An image forming apparatus. A photoreceptor,
Charging means for charging the surface of the photoreceptor;
Exposure means for exposing the surface of the photoreceptor after charging to form an electrostatic latent image;
Developing means for developing the electrostatic latent image to form a toner image;
Heating means for heating and fixing the toner image on a transfer material onto which the toner image formed on the photosensitive member is transferred;
A potential detecting means for detecting a surface potential of the photoreceptor;
Control means for executing an adjustment process for adjusting image forming conditions based on the detection value of the potential detection means;
A memory for storing image formation conditions sequentially set in the adjustment step ,
The control means executes the adjustment step in parallel with the warm-up for causing the heating means to reach the fixing target temperature, receives an image output signal before the adjustment step is completed, and warms up the heating means. When the adjustment process is completed , image formation is started under the image formation conditions stored in the memory when the warming-up of the heating unit is completed before the adjustment process is completed, and the adjustment process is performed as the photosensitive process. Continuously in non-image areas between image areas formed on the body,
An image forming apparatus. A photoreceptor,
Charging means for charging the surface of the photoreceptor;
Exposure means for exposing the surface of the photoreceptor after charging to form an electrostatic latent image;
Developing means for developing the electrostatic latent image with toner;
Heating means for heating and fixing the toner image on a transfer material onto which the toner image formed on the photosensitive member is transferred;
A loading amount detecting means for detecting a toner loading amount of the toner image;
Control means for executing an adjustment process for adjusting the image forming condition based on the detection value of the preceding amount detection means;
A memory for storing image formation conditions sequentially set in the adjustment step ,
The control means executes the adjustment step in parallel with the warm-up for causing the heating means to reach the fixing target temperature, receives an image output signal before the adjustment step is completed, and warms up the heating means. Is completed, the adjustment process is interrupted , and image formation is started under the image formation conditions stored in the memory at the time when the heating means is warmed up . Continue the adjustment process,
An image forming apparatus. A photoreceptor,
Charging means for charging the surface of the photoreceptor;
Exposure means for exposing the surface of the photoreceptor after charging to form an electrostatic latent image;
Developing means for developing the electrostatic latent image with toner;
Heating means for heating and fixing the toner image on a transfer material onto which the toner image formed on the photosensitive member is transferred;
A loading amount detecting means for detecting a toner loading amount of the toner image;
Control means for executing an adjustment process for adjusting the image forming condition based on the detection value of the preceding amount detection means;
A memory for storing image formation conditions sequentially set in the adjustment step ,
The control means executes the adjustment step in parallel with the warm-up for causing the heating means to reach the fixing target temperature, receives an image output signal before the adjustment step is completed, and warms up the heating means. When the adjustment process is completed , image formation is started under the image formation conditions stored in the memory when the warming-up of the heating unit is completed before the adjustment process is completed, and the adjustment process is performed as the photosensitive process. Continuously in non-image areas between image areas formed on the body,
An image forming apparatus. A display unit that displays that image formation is possible in a state where the warm-up of the heating unit is completed and the adjustment step is not completed;
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

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