JPH08262940A - Image forming device and method - Google Patents

Abstract

PURPOSE: To reduce futile toner consumption by avoiding an optimal bias control in an unnecessary case. CONSTITUTION: This device is provided with a bias control means 7 that controls a bias voltage impressed on a developing means and transfer means based on the image forming condition, a measuring means 24 that measures off-time of the power supply during power-on-time, a control decision means 22 that permits the bias control means 7 to execute the bias control when the measured power-off-time exceeds a specified time and does not permit the same to execute the bias control when the power-off-time does not exceed the specified time, and a storing means 21 that stores the process conditions just prior to switching off of power. The control decision means 22 decides further in response to switching on the power, whether or not the contents of the process conditions prior to the power switch off are abnormal, and permits the bias control means to execute the bias control regardless of the power-off-time in the case of an abnormality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus and method, and more particularly to an image forming apparatus and method having a function of controlling a transfer bias and a developing bias.

[0002]

2. Description of the Related Art Conventionally, in this type of image forming apparatus,
When forming a multicolor image, a high-voltage unit that generates a transfer bias applied to the transfer charger and a developing bias applied to the developing unit according to the number of times of transfer is provided. The printer control means is sequentially turned on / off according to the cycle to form a multicolor image.

FIG. 6 shows a printer control mechanism of a conventional multicolor image forming apparatus of this type. In FIG. 6, reference numeral 1 denotes a printer control circuit, which causes the image processing apparatus 2 to generate a video signal (VD ₀ ) 3 based on a multicolor image signal from the printer controller 11 and output it to the drive circuit 4. The drive circuit 4 outputs a laser drive signal 5 for driving a semiconductor laser (not shown) according to the video signal 3.
The image processing device 2 outputs the first and second video signals 3 generated by the input multicolor image signals, and the driving circuit 4,
An image carrier (photoreceptor) (not shown) is irradiated with a laser beam via a semiconductor laser to form first and second electrostatic latent images, and a start signal 6 is output to the bias controller 7. The bias control unit 7 reads from the storage device 10 the condition data for obtaining the corresponding developing bias and transfer bias based on the multicolor image signal from the printer controller 11, and performs the optimum transfer based on the read condition data. Bias and development bias signal 8
Is output to a transfer charger and a developing unit, whereby the above electrostatic latent image is developed and transferred to a recording paper to form a multicolor image.

The detecting means 13 detects the environmental information such as the density information 14, the temperature information 15, the humidity information 16 and the like which are the above-mentioned condition data. The temperature information 15 and the humidity information 16 are
According to the instruction from the image processing device 2, in order to obtain the condition data for performing sufficient bias control, the detecting means 13 is provided at regular intervals regardless of the on / off state of the device power supply.
Detected and stored in the recording device 10. Further, the density information 14 indicates that the image processing apparatus 2 recognizes when a printing operation of a fixed number of sheets is executed, a sudden change in environment, a jam, a change of a developing device, etc., and then an instruction from the image processing apparatus 2 is given. According to the above, after the driving for detecting the density is performed, it is detected by the detecting means 13 and stored in the recording device 10.

[0005]

However, the conventional image forming apparatus as described above is configured as described above, and the control for obtaining the minimum bias is performed according to the instruction of the image processing apparatus. The conditions for executing the above are, for example, when the power is turned on, after the door has been opened for a predetermined time or more, and after the print processing for a predetermined number of sheets has been completed. Especially, power ON
At this time, the optimum bias control is executed to guarantee the optimum image. However, when the user unnecessarily repeats the power ON / OFF, the optimum bias control can be repeatedly performed to guarantee the optimum image. There are problems such as wasting toner.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to avoid optimal bias control when unnecessary, thereby reducing an unnecessary toner consumption amount. It is to provide a forming apparatus and an image forming method.

[0007]

To achieve the above object, the apparatus of the present invention comprises a developing means for developing a latent image on an image carrier and a transfer means for transferring the developed image onto a recording sheet material. Bias control means for adjusting and controlling the bias signal applied to and based on the image forming conditions, measuring means for measuring the time during which the power supply is off when the power switch is on, and the power supply measured by the measuring means. Comparing means for comparing the off time with a specified time, and as a result of the comparison, when the time between the power off times is equal to or more than the specified time, execution of adjustment control of the bias signal by the bias control means is permitted, And a control determination means for determining that the bias control means does not permit execution of adjustment control of the bias signal when the time between power-offs is the specified time or less. And it features.

The apparatus of the present invention preferably, as one aspect thereof, storage means for storing the process condition before the power switch is turned off, and the power switch off stored in the storage means in response to the power switch being turned on. The control determination unit further includes a determination unit that determines whether or not the content of the previous process condition is abnormal, and the control determination unit determines that the determination unit is abnormal even when the time between the power-offs is the specified time or less. In the case of determining, it is possible to make a determination to permit execution of the bias signal adjustment control by the bias control means.

As another aspect, the apparatus of the present invention preferably has a detecting means for detecting density information, temperature information, and humidity information relating to the image forming conditions, and the bias control means detects the detecting means. The adjustment control of the bias signal may be performed based on the output.

Further, in the method of the present invention, the bias signal applied to the developing means for developing the latent image on the image carrier and the transferring means for transferring the developed image on the recording sheet material is used as the image forming condition. In an image forming method for an image forming apparatus having a bias control means for adjusting and controlling based on a first step, a first step of storing a current process condition in a predetermined storage device in response to turning off of a power supply, and an analog value of a capacitor are defined values. Second to charge the capacitor until reaching
And a step of saving the analog value of the capacitor in a predetermined work area A in response to the power switch being turned on.
And a fourth step of charging the capacitor until the analog value of the capacitor reaches a specified value, and at the same time when the counting of the time counting counter is started,
A fifth step of forcibly discharging the capacitor until the analog value of the capacitor reaches the value saved in the work area A; and the time counting counter when the analog value of the capacitor reaches the saved value. A sixth step of calculating the time during which the power is off from the count value of No. 7, a seventh step of determining whether the calculated time between power off is equal to or more than a specified time, and a seventh step In the case of a negative determination in step, an eighth step of checking the previous process condition stored in the storage device to determine whether the content is abnormal, and the seventh or eighth step The step of permitting the bias control means to execute the adjustment control of the bias signal in the case of a positive determination, and the bypass step in the case of a negative determination in the eighth step. Characterized by a step of non-authorized to perform adjustment control of the bias signal according to the scan control means.

[0011]

According to the present invention, the storing means for storing the process condition before the power switch is turned off, the measuring means for measuring the time during which the power is off when the power switch is turned on, and the execution / non-execution of the bias control are determined. Control determination means for
Based on the time from the measuring means and the previous process condition stored in the storage means by the storage means, the control determination means determines whether the bias control means is executed or not. As a result, it is possible to avoid the optimum bias control when unnecessary and reduce the wasteful toner consumption amount.

[0012]

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

(First Embodiment) FIG. 1 shows the configuration of a printer control circuit of an image forming apparatus according to the first embodiment of the present invention.
The same parts as those in FIG. 6 are designated by the same reference numerals.
When the power is turned on, the printer control circuit 1 turns off the output port connected to the image processing apparatus 2,
After performing initialization processing for image formation processing such as abnormality check of an input port of a sensor or the like, the printer controller 11 is notified of a printer operation status and a command from the printer controller 11 is notified via a signal of the video interface 18. The transfer is started and the printer operation such as initial processing and printing operation processing of a desired electrophotographic process set by an operation panel (not shown) is enabled.

In FIG. 1, reference numeral 21 is a power switch OF.
It is a storage unit for storing the process condition before F, and stores the process condition or the like currently in operation in the storage device 10 upon detection of power OFF. Reference numeral 24 is an OFF time measuring means for measuring the time between power OFFs when the power switch is ON. When the power switch information 23 recognizes that the power ON is detected, the time between power OFFs is measured. , And stores the measured count value in an internal time measurement counter (not shown). Reference numeral 22 is a control judging means for judging execution / non-execution of the bias control, and after the power ON information is detected and recognized by the power switch information 23, the initial is determined according to the count value from the OFF time measuring means 24. Indicates execution / non-execution of optimum bias control at time.

The processing operations of the storing means 21, the OFF time measuring means 24, and the control determining means 22 shown in FIG. 1 will be described below with reference to the flow charts shown in FIGS.

The flowchart of FIG. 7 shows an example of the processing procedure of the optimum bias control.

First, in step S61, it is checked whether or not the optimum bias control at the time of initialization is executed.
If not executed, the process is terminated, and if executed, step S62.
Move to In step S62, driving and operation for this optimum bias control, for example, developing / transfer bias high voltage is applied to hit a patch on the transfer drum,
Turn on the scanner and start execution such as turning on the laser.

When the driving of the transfer drum is confirmed, the desired patch take-in timing is checked with reference to the reference sensor on the transfer drum (step S63). When the timing comes, the patch on the transfer drum at that time is taken in by the density sensor, and this density data is stored in the work (step S64). Then, the fetching process (steps S63 and S64) is performed up to a predetermined number (step S65), and the M, C, Y, and Bk toners for all colors are completely fetched (step S66), and for Dmax control and half. The process is repeated until all patch data for tone data has been fetched (step S67).

When the acquisition of all patch data is completed, the process proceeds to step S68, and the optimum bias and optimum halftone table for Dmax of each color of M, C, Y and Bk are calculated from the density data thus acquired ( Step S6
8). Then, the optimum bias control operation and the transfer drum driving are ended (step S69), and a series of processing is ended.

By the operation described above, the optimum bias and the like can be obtained, but at this time, the patch is hit and the toner for the patch generation is consumed to perform the control.

The flowchart of FIG. 2 shows an example of the processing procedure of the storage means 21 shown in FIG. First, step S
In step 21, the power supply OFF detection check is performed, and if it is determined that the power supply is OFF, the process proceeds to step S22, and the process condition data such as the high-voltage bias value currently in operation, the number of prints, the fixing temperature control temperature, the jam information, and the temperature and humidity data are displayed. , And stores it in the storage device 10, and proceeds to the next step.

From step S23 to step S25,
This is a capacitor process for measuring the OFF time. Charge the capacitor until the analog value of the capacitor (not shown) reaches a specified value (a value for maintaining the accuracy of the OFF time) that has been set in advance, and terminate the processing.
The power is turned off.

The flow chart of FIG. 3 is the same as that shown in FIG.
An example of the processing procedure of the FF time detection means 24 is shown. First,
In step S31, a power ON detection check is performed, and if it is determined that the power is ON, the process proceeds to step S32, and the current analog value of the capacitor is saved (stored) in the work A in the RAM (not shown). Next, the capacitor is charged until the analog value of the capacitor reaches a predetermined specified value (value for maintaining the accuracy of the OFF time) (steps S33, S34), and when the specified value is reached, the capacitor is transferred to the capacitor. Then, the electric charge is turned off (step S35). Next, the process moves to the time measuring process.

The counting of the time measuring counter (not shown) is started (step S36), and the forced discharge of the capacitor is turned on until the analog value of the capacitor reaches the value of the work A saved in step S32 (step S37, S38), when the value of the work A is reached, the forced discharge is turned off (step S40), and the counting of the time measuring counter is also ended (step S39).

Then, the process proceeds to step S41. In step S41, the time for discharging to a certain capacitor analog value by natural discharge is calculated from the count value of the time measurement counter by forced charge charging / discharging obtained up to step S40, and the calculated time is set as OFF time. finish.

The flow chart of FIG. 4 shows a processing procedure in the control judging means 22 shown in FIG. First, in step S45, a power ON detection check is performed, and if it is determined that the power is ON, the process proceeds to step S46. Step S
At 46, the count value of the time measuring counter measured by the OFF time measuring means 24 is checked, and if the count value is equal to or more than a predetermined specified value, the execution permission flag of the optimum bias control at the initial time is turned on. If the count value is less than or equal to the specified value (step S47), the execution flag of the optimum bias control at the initial time is turned off (step S48), and the process is terminated.

The image processing apparatus 2 has the execution permission flag set to O.
If it is FF, the activation signal 6 is not output to the bias control means 7, and if the flag is ON, the activation signal 6 is output.

In this way, the power is turned off in response to the power being turned on.
The time is calculated, and the execution / non-execution of the optimum bias control at the initial time is determined based on the power OFF time. Therefore, even when the user repeatedly turns the power ON / OFF unnecessarily, the optimum image is maintained and useless. The consumption amount of toner can be suppressed.

(Second Embodiment) Next, a second embodiment of the present invention will be described. The configuration of the printer control circuit of the present embodiment is the same as that of the first embodiment of the present invention shown in FIG. 1, except that the processing operation of the control determination means 22 is different.

The flow chart of FIG. 5 shows the processing procedure of the control judgment means 22 in the second embodiment of the present invention. First, in step S51, a power ON detection check is performed, and if it is determined that the power is ON, the process proceeds to step S52.
In step S52, the OFF time measuring means 24
The count value of the time measuring counter measured by is checked. If the count value is less than or equal to a predetermined specified value, the process proceeds to step S53, and if the count value is greater than or equal to the specified value, the process proceeds to step S55. .

In step S53, the storage means 21 checks the high-voltage bias value stored in the storage means 10 at the previous power-on, the number of prints, the fixing temperature control temperature, jam information, temperature / humidity data, etc. (step S53). S5
4) If the result of the check shows that it is abnormal, the execution permission flag of the optimum bias control at the time of initialization is turned on.
Then, the processing is terminated (step S55), and when it is determined that there is no abnormality, the execution permission flag of the optimum bias control at the initial time is turned off (step S56), and the processing is terminated.

The judgment of abnormality in step S54 is as follows.
For example, when it is recognized that there is a rapid environmental change by referring to the temperature and humidity data, or when the previous high-voltage bias is already at the default value, or when the previous power-on / off operation due to a jam is recognized, or This is performed when it is recognized that the power is on / off due to the replacement of the developing cartridge.

As described above, in the second embodiment of the present invention, the power OFF time is measured when the power is ON, which is determined in the first embodiment of the present invention, and the optimum bias control at the time of initializing is executed by the power OFF time. Although the power ON / OFF time was short, which was difficult to recognize in the judgment of non-execution, it also recognizes abnormal changes in process conditions that may seriously affect image assurance, and based on this recognition, Since execution / non-execution of the optimal bias control is also determined, it is possible to avoid unnecessary number of optimal bias controls, and suppress wasteful toner consumption while maintaining an optimal image.

[0034]

As described above, according to the present invention,
A storage means for storing the process condition before the power switch is turned off, a measuring means for measuring the time during which the power is off when the power switch is turned on, and a control determination means for determining whether or not the bias control is executed are provided. Since the control determination means determines whether or not to execute the optimum bias control based on the time from the measuring means and the previous process condition stored in the storage means by the storage means, refer to the section of the prior art. Since there is no need to always execute the optimum bias control when the power is turned on as described above, there is an effect that the unnecessary bias consumption can be reduced by avoiding the optimum bias control when unnecessary.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a printer control circuit of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing an example of a processing procedure of a storage unit of FIG.

FIG. 3 is a flowchart showing an example of a processing procedure of an OFF time detection means of FIG.

FIG. 4 is a flowchart showing an example of a processing procedure of a control determination means of FIG.

FIG. 5 is a flowchart showing an example of a processing procedure of a control determination means of a second embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a printer control circuit of a conventional image forming apparatus.

FIG. 7 is a flowchart showing an example of a processing procedure of optimum bias control executed by the bias control means in accordance with an instruction from the control determination means of FIG.

[Explanation of symbols]

 1 Printer Control Circuit 2 Image Processing Device 4 Drive Circuit 7 Bias Control Means 10 Storage Device 13 Detecting Means 21 Storage Means 22 Control Judging Means 24 OFF Time Measuring Means

Claims (4)

[Claims] 1. A bias for adjusting and controlling a bias signal applied to a developing means for developing a latent image on an image carrier and a transferring means for transferring the developed image on a recording sheet material based on image forming conditions. Control means, measuring means for measuring the time during which the power is off when the power switch is on, comparing means for comparing the time between the power off measured by the measuring means and the specified time, As a result, when the time between power-offs is equal to or longer than the specified time, the bias control means permits execution of adjustment control of the bias signal, and when the time between power-offs is equal to or less than the specified time, the bias control means An image forming apparatus, comprising: a control determination unit that determines that execution of adjustment control of the bias signal is not permitted. 2. Storage means for storing the process condition before the power switch is turned off, and whether or not the content of the process condition before the power switch is turned off, which is stored in the storage means in response to the power switch being turned on, is abnormal. The control determination means further includes a determination means for determining whether or not the power-off time is equal to or less than the specified time, and when the determination means determines an abnormality, the control by the bias control means is performed. The image forming apparatus according to claim 1, wherein the image forming apparatus determines whether to permit the adjustment control of the bias signal. 3. A detection unit for detecting density information, temperature information, and humidity information relating to the image forming conditions, and the bias control unit controls the adjustment of the bias signal based on the detection output of the detection unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. 4. A bias for adjusting and controlling a bias signal applied to a developing means for developing a latent image on an image carrier and a transfer means for transferring the developed image on a recording sheet material based on image forming conditions. In an image forming method of an image forming apparatus having a control means, a first step of storing a current process condition in a predetermined storage device in response to power-off of a power source, and a step of storing the capacitor until the analog value of the capacitor reaches a specified value. A second step of charging, a third step of saving the analog value of the capacitor in a predetermined work area A in response to the power switch being turned on, and the capacitor being charged until the analog value of the capacitor reaches a specified value. At the same time as starting the counting of the fourth step and the time counting counter, the analog value of the capacitor is A fifth step of forcibly discharging the capacitor until it reaches the saved value in region A, and turning off the power from the count value of the time counting counter when the analog value of the capacitor reaches the saved value. In the case of a negative determination in the seventh step, a sixth step of calculating the time during which the power supply is off, a seventh step of determining whether the calculated time between power-offs is a prescribed time or more, and a negative determination in the seventh step. An eighth step of checking the previous process condition stored in the storage device to determine whether or not the content is abnormal, and the bias in the case of a positive determination in the seventh or eighth step. A step of permitting the control means to execute the adjustment control of the bias signal; and a negative signal in the eighth step, the bias signal of the bias control means. Image forming method, the step of disabling the execution of the adjustment control of the signal.