CN1262892C - Process cartridge, memory medium for the process cartridge, image forming apparatus and image formation control system - Google Patents

Abstract

A memory medium is provided to a cartridge detachably mountable to an image forming apparatus. Into the memory medium, as information for performing charge control, information on the amount of usage of an image-bearing member and information on a charging alternating voltage (a threshold value for selection control of a charging peak-to-peak voltage Vpp) are written. The image forming apparatus includes a charging-bias power-supply circuit, on its body side, including AC oscillation output circuit capable of outputting two or more species of alternating peak-to-peak voltages and an AC detector for detecting an alternating current passing through the image-bearing member. Charge control is performed on the basis of a detected value detected by the AC detector and memory information for the cartridge, whereby good charge control space saving, and cost reduction of the power-supply circuit are compatibly realized.

Description

Handle box is used for storage medium, imaging device and the imaging control system of handle box

Technical field

The present invention relates to a kind of handle box that adopts electrophotography, electrostatic recording etc.; A kind of storage medium that is used for handle box; A kind of imaging device and a kind of imaging control system.

Background technology

Figure 18 represents the schematic section of an embodiment of common imaging device.

The imaging device of present embodiment is an electrophotographic copier or printer.

With reference to Figure 18, this imaging device comprises a rotary drum type electronic photographic photosensitive component 100 (hereinafter referred to as " photosensitive drum ") as the sub-image load bearing component.Photosensitive drum 100 drives by predetermined circle speed rotatably along the direction of arrow, during rotation is charged as predetermined polarity and predetermined potential equably by a charging equipment 101, stands the image style exposure of an exposure sources 102 then.As a result, on the photosensitive drum surface, form a width of cloth electrostatic latent image, develop by a developing apparatus 103 usefulness toners then, to be revealed as toner image.Be transferred to unshowned sheet feed section branch is supplied with from one recording medium 104 by a transfer apparatus 105 for example on the paper at the toner image that forms on the photosensitive drum surface.After toner image is transferred on it, recording medium 104 from the dismounting of photosensitive drum surface, to send into a fixation facility 106, is made toner image by this fixation facility 106, to discharge as the piece image finished product.After the recording medium dismounting, the photosensitive drum surface obtains cleaning by a cleaning equipment 107 by scraping off the transfer printing remaining toner, and repeatedly stands imaging.

As mentioned above, by the device of above-mentioned imaging device, the step of recharge, exposure, development, transfer printing, photographic fixing and cleaning is carried out imaging.

As for charging equipment 101, use those charging equipments of using the contact charging scheme widely, a roll-type or vane type charging unit are contacted with the photosensitive drum surface, simultaneously the contact charging unit is applied voltage, so that the photosensitive drum surface charging.Especially, use the contact charging scheme of roll-type charging unit (charging roller) to allow the constant charge in long-time to operate.

From a charging biasing bringing device charging roller as the contact charging parts is applied a charging bias voltage.The charging bias voltage can only be made up of dc voltage, but also can comprise the bias voltage that a dc voltage Vdc who setovers or superpose with AC voltage is formed, here the dark-coloured part current potential of the hope on dc voltage Vdc and photosensitive drum Vd is corresponding, and AC voltage has a P-to-P voltage (Vpp), and it is the twice of the discharge ionization voltage when applying dc voltage Vdc at least.Using such bias voltage is the known conditions (Japanese Laid-Open PatentApplication (JP-A) Sho 63-149669) of realizing even chargeable property.

This charging scheme is for being good with photosensitive drum surface uniform charging, and comprises with the voltage of the dc voltage of AC voltage bias by applying one, eliminated the local potential scrambling on the photosensitive drum.The charging voltage Vd that forms converges on the dc voltage value Vdc that applies equably.

Yet, when with only apply the dc voltage component relatively as the situation of charging bias voltage, this scheme has increased the discharge charge amount, thereby is easy to quicken surface degradation, photosensitive drum is surperficial owing to the abrasion between photosensitive drum surface and the cleaning equipment are worn and torn like this.In order to prevent such surface degradation, require the AC P-to-P voltage Vpp of charging roller by the bias voltage that suppresses to charge, prevent over-discharge can for photosensitive drum.

Yet, AC P-to-P voltage (Vpp) always and the relation between the discharge charge amount inconstant because it is with variations such as the thickness of the lip-deep photosensitive layer of photosensitive drum, operating environment conditions.

For example, even when a charging roller is applied same P-to-P voltage, the impedance of charging roller increases under low temperature and low-humidity environment, has reduced the discharge charge amount.On the other hand, under high temperature and high humidity environment, this impedance reduces, and the discharge charge amount is increased.In addition, even under same operating environment, when using wearing and tearing to cause abrasion when the photosensitive drum surface because with it, the impedance and the starting stage of formation relatively reduce, thereby cause a large amount of discharge charges.

In order to eliminate this problem, proposed to control the method (U.S.Patent No.5,420,671, corresponding to Japanese Patent Publication (JP-B) No.Hei 06-093150) of AC component with steady current.According to this method, detect and control and flow through the alternating current Iac of photosensitive drum (photosensitive part), so that be constant.As a result, P-to-P voltage freely changes with the caused impedance variation of the abrasion of environmental change or photosensitive drum, and is total so that might keep the discharge charge amount fully constant, and has nothing to do with the thickness of environmental change, photosensitive drum etc.

In addition, U.S.Patent Publication No.2001-19669 (corresponding to JP-A2001-201920) discloses a kind of method, wherein when non-imaging when charging equipment being applied one when exchanging P-to-P voltage Vpp, by detecting the alternating current Iac that flows through photosensitive drum with respect to region of discharge and absence of discharge district, and according to the Iac value with respect to the relation between region of discharge and the absence of discharge district, calculate the discharge current amount, obtain an AC voltage that allows suitable discharge capacity, this AC voltage is setovered as charging.According to this method, discharge current is further directly controlled, so as with conventional steady current control ratio, become and might control discharge current accurately.

Said method is bringing many influences aspect increase life-span that guarantees photosensitive drum and the good chargeable property.

As mentioned above, for irrespectively to control the discharge charge amount fully constant with the use pattern, might adopt No.5,420 as U.S.Patent, 671 described AC steady current control methods, or as the described discharge capacity computing method of U.S.Patent Publication No.2001-19669.Yet, in these methods, shown in Figure 16 A, when from the superimposed voltage of a single supercharging device T-AC output AC and DC, exchanging P-to-P voltage is set under high temperature or high humidity, or use the later stage of (imaging) to reduce at photosensitive drum, so can not obtain the voltage that the capacitor that produces dc voltage is charged fully.As a result, do not carry out good charging, can produce difficulty in some cases, the charging failure for example occurs photosensitive drum according to the environmental baseline of using.

, state in the use under the situation of method for this reason, restricted for output with the superimposed voltage of the AC of single supercharging device and DC.Therefore, shown in Figure 16 B, in order to obtain stable charging bias voltage, a DC power supply T-DC and an AC power supplies are arranged in dismounting ground, thereby require to install DC and two supercharging devices of AC.

Yet supercharging device is not only expensive, and occupies large-size within charging generation circuit.As a result, in the imaging device that reduces size and reduce cost, consider that the space of power circuit is saved and the cost reduction, wish from a stable charging bias voltage of single supercharging device output.

In addition, JP-A HEI 09-190143 discloses a kind of method, wherein make a handle box have detection and the memory storage of the running time of this handle box, and be provided with one and exchange P-to-P voltage, so that at least two kinds of constant voltage outputs to be provided, with the thickness of estimation photosensitive drum, thereby be classified to reduce to exchange P-to-P voltage.

Shown in Figure 16 A, under these circumstances, wherein the AC component is controlled with a constant voltage, then step-up transformer (supercharging device) T-AC of AC output is connected with a capacitor C who is used to produce dc voltage by a diode D, and this capacitor is charged fully, can produce a dc voltage, might provide a kind of power supply architecture, so that only with stack biasing of single supercharging device T-AC output with the DC of AC biasing so become.

If use this power supply architecture, do not need to be used in combination DC power supply and AC power supplies, so with the situation of steady current control relatively, simplified power circuit significantly.As a result, reduce cost and save the space with regard to it, this power circuit brings a plurality of advantages.

Yet, in the described method of JP-A HEI 09-190143, the offset generating circuit that wherein charges is made up of a single supercharging device, and provide two or more constant voltage outputs, with the output AC P-to-P voltage, with use amount according to photosensitive drum, progressively reduce P-to-P voltage, then carry out voltage transitions (reducing to exchange P-to-P voltage) predetermined regularly (when photosensitive drum uses the schedule time).As a result, for example,, P-to-P voltage prescribes a time limit when being output as the following of tolerance limit, even the discharge charge amount is in proper range, also carry out voltage transitions, thereby cause not enough discharge capacity, causing the charging failure in some cases according to the power-supply tolerance etc. of charging offset generating circuit.On the other hand, when the output of P-to-P voltage is prescribed a time limit on tolerance limit, even can expect that discharge capacity is excessive, before predetermined timing, can not carry out voltage transitions, thereby quicken the wearing and tearing and the abrasion of photosensitive drum.As a result, this method is worse than above-mentioned steady current control method with regard to the accuracy of discharge control.The problems referred to above can solve by resistance that reduces charging equipment and/or the power-supply tolerance that charges offset generating circuit, but less power-supply tolerance requires at the cost of regulating power-supply tolerance, thereby unfavorable with regard to production cost.

Consider these situations, wish to carry out charging control,, also can not cause the charging failure, and the degree of wear of photosensitive part (drum) is kept minimum even use the simple power circuit of the stack biasing of an enough single supercharging device output AC of energy and DC.

Summary of the invention

The present invention realizes in order to address the above problem.

An object of the present invention is to provide a kind of handle box, a kind of storage medium that is used for handle box, a kind of imaging device and a kind of imaging control system that can carry out suitable charging control.

A specific purpose of the present invention provides a kind of handle box that can carry out suitable charging control, a kind of storage medium that is used for handle box, a kind of imaging device, with an imaging control system, in a kind of power source design, by stack biasing conduct charging bias voltage, so that produce dc voltage with the AC supercharging device with AC and dc voltage.

Another object of the present invention provides a kind of imaging device and imaging control system, by canned data in the memory storage that utilizes handle box, can carry out suitable charging control.

Another object of the present invention provides a kind of storage medium that is used for handle box, this handle box, a kind of imaging device and a kind of imaging control system, in the imaging device of such power source design, with the information stores of the use amount of handle box in storage medium, the individual difference that adapts to handle box then in advance, to be used for selecting being fit to timing (threshold value of the use amount of the handle box) information of charging AC voltage (charging P-to-P voltage) of individual cassette characteristic and charging AC voltage (charging P-to-P voltage) information stores at storage medium, and produce a dc voltage of setovering as charging with an AC supercharging device.

Another object of the present invention provides a kind of handle box, a kind of storage medium that is used for handle box, and a kind of imaging device and a kind of imaging control system, it can realize that the space of power circuit is saved and cost reduces, and allows suitably charging control.

According to the present invention, a kind of imaging device is provided, comprising:

An image bearing member,

A charging unit is used for the image bearing member charging,

Voltage output device can apply a plurality of alternating voltages with varying level to charging unit,

A storer is used to store the information that is used for selecting one of a plurality of alternating voltages,

Pick-up unit, when from voltage output device during to the charging unit output AC voltage, be used to detect the electric current that flows through image bearing member and

Control device is selected the information of one of a plurality of alternating voltages and the detected value of the electric current that pick-up unit detects according to being used for of storing in the storer, and is used to determine during imaging from the alternating voltage of voltage output device to charging unit output.

According to the present invention, a kind of handle box also is provided, comprising:

An image bearing member,

A charging unit, be used for to image bearing member charging and

A storage medium, the information that is used to store relevant this handle box,

Wherein can supply with a plurality of alternating voltages to charging unit with varying level, and

Storage medium has a memory block that is used to store the information that is used for selecting one of a plurality of alternating voltages.

According to the present invention, a kind of storage medium also is provided, be installed on the handle box, this handle box is removably mounted on the imaging device, and this handle box comprises an image bearing member and a charging unit that is used for the image bearing member charging, wherein can supply with a plurality of alternating voltages to charging unit with varying level, and

Storage medium comprises:

A memory block that is used to store the information that is used for selecting one of a plurality of alternating voltages,

The information that wherein is used for selecting one of a plurality of alternating voltages is the information that is used to determine being applied to the alternating voltage on the charging unit during the imaging, and assigns to determine by the control part of imaging device.

According to the present invention, a kind of control system also is provided, be used to control a kind of imaging device that comprises an apparatus body and a handle box, wherein imaging device comprises an image bearing member, a charging unit that is used for the image bearing member charging, can apply the voltage output device of a plurality of alternating voltages to charging unit with varying level, with when from voltage output device during to the charging unit output AC voltage, be used to detect the pick-up unit of the electric current that flows through image bearing member, and wherein control system comprises a storage medium, be installed on the box, has a memory block that is used to store the information that is used for selecting one of a plurality of alternating voltages, and control device, according to the information that is used for selecting one of a plurality of alternating voltages of storing in the storer, the detected value of the electric current that detects with pick-up unit is used to determine during imaging from the alternating voltage of voltage output device to charging unit output.

The description of together with accompanying drawing the preferred embodiments of the present invention being done below considering, these and other purposes of the present invention, characteristics and advantage will become more apparent.

Description of drawings

Fig. 1 is the schematic section of expression according to the processing boxlike imaging device of the used detachable installation of the first embodiment of the present invention of the following stated.

Fig. 2 is the schematic section from the handle box of imaging device dismounting.

Fig. 3 is the synoptic diagram of the sequence of operation of expression imaging device.

Fig. 4 is the block scheme of expression charging bias power supply circuit.

Fig. 5 is the curve map that expression exchanges the relation between P-to-P voltage and the available output dc voltage.

Fig. 6 is a process flow diagram of determining the method for charging biasing among expression first embodiment.

Fig. 7 is the curve map of environmental baseline and the relation between the AC electric current (detection voltage) of charging among expression first embodiment and second embodiment.

Fig. 8 is the curve map of the use amount and the relation between the charging AC electric current (detection voltage) of photosensitive drum among expression first embodiment.

Fig. 9 is the view that is used to illustrate an example of the charging biasing when printing.

Figure 10 is the view that is used to illustrate the detection voltage when determining the charging biasing.

Figure 11 is a process flow diagram of determining the method for charging biasing among expression second embodiment.

Figure 12 is the curve map of the use amount and the relation between the charging AC electric current (detection voltage) of photosensitive drum among expression second embodiment.

Figure 13 is a process flow diagram of determining the method for charging biasing among expression the 3rd embodiment when printing.

Figure 14 is the process flow diagram that the charging biasing when printing applies order among expression the 3rd embodiment.

Figure 15 is the curve map of the use amount and the relation between the charging AC electric current (detection voltage) of photosensitive drum among expression the 3rd embodiment.

Figure 16 A and Figure 16 B are the views of representing the normal charge bias power supply circuit separately.

Figure 17 is the detailed view that expression is combined in the storer in the box.

Figure 18 is the schematic section of expression conventional imaging equipment.

Embodiment

＜the first embodiment 〉

(1) layout of imaging device and operation

Fig. 1 is the schematic section according to the imaging device of present embodiment.This imaging device is the laser beam printer of an electrofax and disassembly treating box scheme.

With reference to figure 1, imaging device comprises a rotary drum type electronic photographic photosensitive component (photosensitive drum) 1 as image bearing member, and it is parts to be charged.In the present embodiment, photosensitive drum 1 is the organic photosensitive parts that can bear charging, and is rotatably driven by predetermined circle speed by the clockwise direction of a unshowned driving motor along arrow.During rotation, photosensitive drum 1 is charged as the predetermined negative current potential equably by a charging equipment.Charging equipment is a contact charging equipment, uses charging roller 2 as charging unit.

Charging roller 2 cooperates with photosensitive drum 1 rotation.Apply a bias voltage from a charging bias supply (not shown) to charging roller 2.The charging bias voltage applies scheme according to stack and applies, wherein with one with photosensitive drum on the corresponding dc voltage of hope surface potential superpose or setover one and have the AC voltage of P-to-P voltage (Vpp), P-to-P voltage (Vpp) is the twice of discharge ionization voltage at least.This charging method is by applying the dc voltage with the AC voltage bias, the same current potential of dc voltage that the photosensitive drum surface is charged as equably and applies.

Then, make photosensitive drum 1 stand the image style exposure of exposure sources 1.Exposure sources 21 will form electrostatic latent image on the uniform charging surface of photosensitive drum 1, and will comprise a semiconductor laser beam scanner in the present embodiment.The laser L of the corresponding modulation of picture (image) signal that a main equipment (not shown) within exposure sources 21 outputs and the imaging device is sent, and, scan exposure (exposure of image style) is carried out on the uniform charging surface of photosensitive drum 1 by the exposal window of a catoptron 21a and handle box C (hereinafter describing).On the photosensitive drum surface, become less than the absolute value of charging potential at the absolute value of exposure position, thereby form electrostatic latent image continuously according to view data.

With a reverse developing apparatus 5 make latent electrostatic image developing, to be revealed as toner image thereafter.In the present embodiment, use jump development scheme.According to this development scheme, by applying a development bias voltage that comprises the superimposed voltage of AC and DC to development sleeve 7 from a unshowned developing bias power supply, in the contact portion of development sleeve 7 with developer bed thickness adjusting portion part 6, the toner of negative charging oppositely develops the electrostatic latent image that forms on the photosensitive drum surface with frictional electricity.

The lip-deep toner image of photosensitive drum is transferred to recording medium (transfer materials) by a transfer apparatus, for example from the paper of a paper feed (not shown) supply.The used transfer apparatus of present embodiment is the contact transfer-type, and comprises a transfer roll 22.Transfer roll 22 by a device for exerting (not shown) for example pressure spring press to the center position of photosensitive drum 1.When by transmission transfer materials starting transfer step, apply a positive transfer bias from a unshowned transfer printing bias supply to transfer roll 22, thereby the lip-deep negative charging toner of photosensitive drum is transferred on the transfer materials.

The transfer materials that stands the toner image transfer printing, wherein with toner image thereon, is discharged to transfer materials on the paper output tray 25 by a paper path 24 to send into a fixation facility 23 then from the dismounting of photosensitive drum surface.Fixation facility 23 utilizes heat or pressure will be transferred to toner image photographic fixing for good and all on the transfer materials.

At the transfer materials after separating, the photosensitive drum surface scrapes off the transfer printing remaining toner by cleaning equipment 4 a usefulness cleaning blade 3 and obtains cleaning.Cleaning blade 3 will be recovered in the transfer step not from photosensitive drum 1 and be transferred to transfer printing remaining toner on the transfer materials, and with certain pressure near photosensitive drum 1, reclaiming the transfer printing remaining toner, thereby cleaning photosensitive drum surface.After finishing cleanup step, charge step is stood on the photosensitive drum surface again.

Imaging device repeats each step of above-mentioned charging, exposure, development, transfer printing, photographic fixing and cleaning by utilizing said apparatus respectively, carries out imaging.

In the present embodiment, handle box C is replaceable and be removably mounted on the main body 20 of imaging device, and comprise four treatment facilities, promptly be used as the photosensitive drum 1 of sub-image load bearing component, charging roller 2 as the charging unit that contacts with photosensitive drum 1, developing apparatus 5 and cleaning equipment 4, they integrally are supported in the equipment body 20.In addition, handle box C has a storer 10 as storage area.By the communicator (not shown) on the base side of imaging device, carry out and read or writing information from storer 10.

By opening or closing a box door (body door) 20a of main body 20, make handle box C adhere to or separate with the main body 20 of imaging device.Carry out the installation of handle box C in this manner,, then box door 20a is closed so that handle box C is inserted and is installed on the equipment body 20 by predetermined way.The handle box C that installs like this on equipment body 20 is in the state that a kind of main body 20 examples with imaging device are mechanical and be electrically connected in a predefined manner.

By opening the handle box C that pulls out in a predefined manner after the box door 20a within the equipment body, carry out slave unit main body 20 and remove handle box C.Fig. 2 is illustrated in the handle box C under the state of removing.Under the state of removing of handle box C, drum covers 8 and moves on to off-position, to cover and to protect the bottom surface section of exposing of photosensitive drum 1.In addition, exposal window also remains on closed condition by a shutter 9.Drum cover 8 and shutter 9 move on to and remain on open position under the installment state of the handle box C within the equipment body 20 respectively.

Here, detachably be installed in during setting up on the imaging equipment body be equipped with at one, by integrally supporting charging device, developing apparatus or cleaning plant with electronic photographic photosensitive component, or by integrally supporting at least one in photosensitive part and charging device, developing apparatus and the cleaning plant, or, prepare handle box by integrally supporting developing apparatus and photosensitive part at least.

(2) printer operation order

With reference to figure 3, the cutline of printer operation order in the present embodiment will be provided.

With reference to figure 3, when connecting the power supply of imaging device, begin rotating multi step in advance, and during the driving that makes the photosensitive drum rotation by main motor, that carries out handle box deposits the detection that is in or be not in and the cleaning of transfer roll.

After finishing in advance rotating multi, imaging device is changed to wait (standby) state.When for example principal computer was to imaging device transmitted image data from a not shown output unit, main motor drove imaging device, thereby equipment is changed to preceding rotation step.In preceding rotation step, be implemented as the preparatory function of the printing of various treatment facilities, for example to the preparation charging on photosensitive drum surface, determining of biasing printed in the starting of laser beam scanner, transfer printing, and the control of the temperature of fixation facility.

Before finishing, after the rotation step, begin printing step.During printing step, carry out supply at predetermined transfer materials regularly, in the lip-deep image style exposure of photosensitive drum, develop etc.After finishing printing step, existing under the situation of print signal subsequently, imaging device is set at interval by paper, up to supplying with printed material subsequently, thereby prepare printing subsequently.

After finishing printing, if there is no print signal subsequently is changed to back rotation step with imaging device.In back rotation step, carry out and remove, and/or the toner that will be attached on the transfer roll is shifted to photosensitive drum (cleaning of transfer roll) at the lip-deep electric charge of photosensitive drum.

After finishing, after the rotation step, again imaging device is changed to wait (standby) state, and waits for print signal subsequently.

(3) generation of charging biasing and suitably determining of charging biasing

Present embodiment is characterised in that, the handle box C that has memory storage 10 is removably mounted on the main body 20 of imaging device, and by using the device of the information in the memory storage 10 being carried out read-write operation, and according to canned data in the memory storage 10, vibration by P-to-P voltage detects the charging AC that flows through photosensitive drum 1, to detect bias voltage as charging biasing AC voltage with one when the imaging, carry out the control of charging biasing, this charging biasing AC voltage has a minimum and is not less than the value that makes the desired minimum charging corresponding magnitude of voltage of AC of photosensitive drum 1 uniform charging (threshold voltage).Minimum charging AC be one at the current value that applies under the P-to-P voltage situation, so that under the situation of a small amount of discharge of charging roller, in the part that does not have enough to carry out the charging of photosensitive drum, can not form stain image (drift sand is like image), promptly do not cause the appearance of charging scrambling.

3-1) the generation (charging bias power supply circuit) of charging biasing

With reference to figure 4, will the used charging bias power supply circuit 30 of present embodiment be described.

With reference to figure 4, charging bias power supply circuit 30 can be from five different interchange P-to-P voltage Vpp of AC vibration output 31 outputs, i.e. Vpp-1, Vpp-2, Vpp-3, Vpp-4 and Vpp-5 (Vpp-1＞Vpp-2＞Vpp-3＞Vpp-4＞Vpp5).By utilizing a control device 38 in the engine controller 37 to control AC output selection device 40, selectively carry out the output of these P-to-P voltages Vpp-1 to Vpp-5.

At first, amplified by an amplifying circuit 32 from the output voltage of AC vibration output 31 outputs, by a sinusoidal voltage change-over circuit 33 that comprises operational amplifier, resistor, capacitor etc., convert sine wave to, remove the DC component by a capacitor C1, and be input to a step-up transformer T1 as supercharging device.The voltage that is input to step-up transformer is enhanced to and the corresponding sine wave of the coil turn of transformer.

On the other hand, strengthen sinusoidal voltage, then a capacitor C2 is charged fully, thereby produce certain dc voltage Vdc1 by rectification circuit D1 rectification.In addition,, export an output voltage of for example determining,, be input to the negative input end of operational amplifier IC1 then by rectification circuit 35 rectifications according to print density from a DC oscillatory circuit 34.Simultaneously, with two resistors of a usefulness to one of the terminal voltage of step-up transformer T1 dividing potential drop given voltage Vb, be input to the positive input terminal of operational amplifier IC1, drive a transistor Q1 then, so that voltage Va and Vb equate mutually.As a result, current flows through resistor R1 and R2 cause that voltage reduces, thereby produce a dc voltage Vdc2.

With above-mentioned dc voltage Vdc1 and Vdc2 addition, can obtain the dc voltage of a hope, then with this dc voltage that superposes of the above-mentioned AC voltage on the secondary side of AC supercharging device T1, so that the charging roller within the handle box C 2 is applied the voltage of this formation.In other words, the used method of present embodiment is the constant voltage controlling schemes, wherein export dc voltages of interchange P-to-P voltages stack of 31 outputs, and the superimposed voltage that will form is applied on the charging roller 2 by 40 selections of AC output selection device and from the AC vibration.

Incidentally, in the present embodiment, dc voltage is produced by AC supercharging device T1, so that dc voltage depends on P-to-P voltage Vpp.In other words, for the dc voltage Vdc that obtains to wish, must under certain level, charge to capacitor C2.Therefore, as shown in Figure 5, carrying out in the scheme of charging with the superimposed voltage of DC and AC voltage, in order to obtain predetermined dc voltage Vdc ', exchange P-to-P voltage Vpp and require to be at least 2 * | Vdc ' |.If exchange P-to-P voltage Vpp less than 2 * | Vdc ' |, capacitor C2 can not charge fully, thereby predetermined dc voltage Vdc ' can be provided.As a result, can not be with the photosensitive drum surface charging to having and the current potential Vd that wishes that level equates, thereby can not provide superior images.

As mentioned above, according to relevant environmental baseline, Vpp is made as different value with P-to-P voltage.Especially, under high temperature and high humidity environment, Vpp is made as smaller value with P-to-P voltage, so as the charging voltage Vpp that forms becoming in some cases less than 2 * | Vdc ' |, reduced the AC voltage level.As a result, capacitor C2 not exclusively charges, and at the dc voltage that does not obtain in some cases to wish.

Therefore, in the present embodiment, be provided with and can export the minimum value Vpp-min of the 31 available interchange P-to-P voltage Vpp that exported from exchanging vibration, to satisfy relation following and predetermined dc voltage Vdc ', to obtain preferable image:

Vpp-min≥2×|Vdc’|。

As a result, even establish P-to-P voltage less under high temperature and high humidity environment, the Vpp-min of formation also is not less than 2 * | Vdc ' |, thereby produce the dc voltage of wishing.

That 3-2) suitably charges and setover determines

Below, will method that determine the charging bias voltage when imaging be described with reference to figure 4, Fig. 6 and Fig. 8.

With reference to figure 4, when charging roller 2 being applied charging bias voltage (charging P-to-P voltage), alternating current Iac flows through high-voltage power circuit GND by charging roller 2 and photosensitive drum 1.At that time, AC testing circuit 36 utilizes a unshowned filtering circuit, detect and only select an alternating current component, it has a frequency that equates with the charge frequency of alternating current Iac, and the alternating current component of selecting is converted into a corresponding voltage, and this value is input to engine controller 37 then.Charging AC current value is in some cases with the circulation change of photosensitive drum.Especially, because coating unevenness during production stage and the abrasion scrambling that causes because of eccentricity are causing the thickness scrambling of photosensitive drum in some cases, thereby are causing the fluctuation of impedance at circumferencial direction.As a result, even when applying identical charging AC voltage (charging P-to-P voltage), the AC electric current I ac of formation also fluctuates, so preferably in order to improve accuracy of detection, by detecting at least one cycle period of photosensitive drum, carry out and for example ask average processing.Incidentally, AC testing circuit 36 for example can be made up of resistor, capacitor and diode, thereby lessly influences the cost of power circuit and the increase in space.

The input voltage and the predefined starting voltage V0 that are input to the controller 38 of engine controller 37 are compared.Incidentally, starting voltage V0 (corresponding with the magnitude of voltage of the pairing AC current detection circuit of Iac-0) is an output voltage for the minimum interchange P-to-P voltage that does not cause the charging scrambling, and determines its value according to the minimum current value Iac-0 that can carry out uniform charging.The value of Iac-0 is with processing speed, charge frequency and the charging equipment 2 of equipment and the changes in material of photosensitive drum 1.For this reason, preferably under the situation starting voltage V0 is being set equally suitably separately.

At this moment, output voltage V 1 is set applying under the maximal value Vpp-1 that can apply the AC P-to-P voltage, satisfying V1 〉=V0 in any environment, thereby can not occurs the charging failure in any environment by maximal value Vpp-1 is set.

Controller 38 in the engine controller 37 is for the storer 10 of the memory storage that is used as handle box C, and execution information is read or information writes.By utilizing canned data in the storer 10, controller 38 is carried out the control of charging biasing.

Storer 10 is designed to the information of stores processor box C, and for example has the memory block of the information of a use amount that is used to store photosensitive drum.

Secondly, with reference to the process flow diagram of figure 6, will the process that the charging biasing is determined in the present embodiment be described.

At first, handle box C is installed on the main body 20 of imaging device, and when body door 20a closes (step S101), imaging device is changed to charging current detecting pattern (step S102).Carrying out this pattern during the rotating multi in advance, and when under conversion regime, applying charging AC voltage (charging P-to-P voltage) Vpp-k (Vpp-k:k=5 to 1), the AC electric current I ac-k that will flow through photosensitive drum 1 feeds back to the controller 38 in (being input to) engine controller 37 as detecting voltage Vk.At this moment, value Vk can be stored in the storer 10 of handle box C.

Figure 10 is when being illustrated in the charging current detecting pattern of step S102, applies under conversion regime under the situation of charging AC voltage Vpp (charging P-to-P voltage), detects the view of the state of voltage Vk.Vpp is transformed into Vpp-5 from Vpp-1, to detect charging current, as detecting voltage V1 to V5.In Figure 10, for the necessary electric current of minimum, the minimum Vk that is not less than starting voltage V0 is V2, thus require to apply charging AC voltage Vpp-2, to obtain the output voltage of a V2.Charging AC voltage when as a result, Vpp-2 is defined as imaging.

In the storer 39 of the memory storage that is used as engine controller 37, storage and the corresponding starting voltage V0 of charging minimum current I ac-0.Relatively Vk and V0 (step S103) are with the charging biasing (hereinafter referred to as " printing biasing ") (step S104) of (during imaging) when Vpp-n is defined as printing of a minimum charging AC voltage (charging P-to-P voltage) that satisfies Vk 〉=V0.

Fig. 8 is the curve map of the relation between the durability degree (use amount of photosensitive drum) of expression charging AC voltage and photosensitive drum.With reference to figure 8, Vpp-n is expressed as minimum charging AC voltage.Each printing is write the storer 10 of handle box C with the information of the use amount of photosensitive drum, thereby be stored and upgrade.

Then, in mainframe memory storage detect poor Δ between voltage V (n+1) m and the starting voltage V0=| V (n+1) m-V0| (step S105) is applying detection voltage V (n+1) m under the magnitude of voltage Vpp-(n+1) than applying charge the little one-level of detection voltage Vnm under the AC voltage Vpp-n of minimum.Imaging device be changed to ready-to-print state (step S106) thereafter.The saved differences Δ is so that suitably be provided with charging AC voltage according to the drum use amount during printing.

Secondly, refer step S107 and later step are with the order during the explanation printing.

Monitoring value Vn (step S107) during printing.During printing, carry out imaging, increase with the drum use amount but detect voltage Vn by applying definite charging AC voltage Vpp-n.The bulging use amount that is stored in the storer 10 of handle box C is read by the controller 38 of engine control 37, and for example calculates and detect poor between voltage Vn and the detection voltage Vnm when bulging use amount reaches A (threshold value) | Vn-Vnm|.When difference | Vn-Vnm| be not less than Δ=| during V (n+1) m-V0| (step S108), the charging AC voltage during with imaging is transformed into Vpp-(n+1) from Vpp-n.Simultaneously, with difference from Δ=| V (n+1) m-V0| be transformed into Δ=| V (n+2) m-V0| (step S109).

The value A of drum use amount can be stored in the memory storage 39 in the engine controller 37.In addition, difference DELTA can be stored in the storer 10 of handle box C.

After finishing printing, to rouse the storer 10 (step S110) that use amount (according to the value of at least one calculating in printer paper number, drum rotation number and the charging biasing application time) writes handle box C, and then imaging device will be changed to ready-to-print state (S111).

Above-mentioned conversion operations can by the actual Vpp-(n+1) that applies, be carried out after affirmation detection voltage is not less than V0 during preceding rotation or back rotation.

(4) effect of present embodiment

4-1) to the influence of the output tolerance limit P-to-P voltage of operating environment and equipment body

According to present embodiment, even operating environment changes, or the output valve of the P-to-P voltage of the main body of imaging device changes between the upper and lower bound of the output tolerance limit of power circuit, shown in Fig. 6 process flow diagram, when installing process cartridge, use the charging current detecting pattern, thereby allow to select suitable charging biasing.

In addition, the situation of different operating environment will be described with reference to figure 7.

Fig. 7 represents when identical imaging device is applied charging voltage Vpp-1 to Vpp-5, the relation between the detection voltage that operating environment (high temperature and high humidity environment (HT/HH), normal temperature and normal humidity environment (NT/NH) and low temperature and low-humidity environment (LT/LH)) and AC current sensing means are detected.

Charging equipment has a big and little impedance under the HT/HH environment under the LT/LH environment, thereby the variation that brings AC current value I ac.

With reference to figure 7, the minimum P-to-P voltage that is used to detect required minimum current value Iac-0 (voltage V0 is corresponding with detecting) is Vpp-2 under LT/LH environment and NT/NH environment, and is Vpp-3 under the HT/HH environment.Therefore, select these P-to-P voltages Vpp respectively.

In the present embodiment, being provided with can be from the minimum value Vpp-min within the output area of the AC vibration output 31 available P-to-P voltages of being exported, with with respect to the predetermined dc voltage Vdc ' that does not cause charging failure, satisfy relation: Vpp-min 〉=2 * | Vdc ' |, even so causing under the HT/HH environment of less AC P-to-P voltage, also minimum P-to-P voltage Vpp-min is made as and is not less than 2 * | Vdc ' |.As a result, might export the AC P-to-P voltage, it can make the photosensitive drum uniform charging, and irrelevant with operating environment.

As mentioned above, change, also when installing process cartridge, carry out charging current and detect, to determine charging AC voltage (charging P-to-P voltage) Vpp according to photosensitive drum even when operating environment changes, cause the impedance of charging equipment.As a result, excessively the AC electric current can not flow through photosensitive drum, and can not cause the charging failure, thereby allows good charging control.

4-2) to the influence of the fluctuation of print paper number

As shown in Figure 8, the AC current value increases with the printer paper number of photosensitive drum.This is attributable to owing to the abrasion on photosensitive drum surface (wearing and tearing) make impedance and reduces.

With reference to figure 8, Vpp-n is set, and, after detecting, Vpp-n is setovered as printing in the starting stage that monitors Vn.When difference | Vn-Vnm| reach at least Δ=| during V (n+1) m-Vo|, in drum use amount A or afterwards, when imaging with Vpp-(n+1) as printing biasing.In addition, when drum use amount B, applying the detection voltage Vn+1 under the Vpp-(n+1) and applying difference between detection voltage V (n+1) m under Vpp-(n+1) m during at drum use amount B | Vn+1-V (n+1) m| reach at least difference DELTA=| V (n+2) m-V0|, so in drum use amount B or afterwards, when printing with Vpp-(n+2) as printing biasing.

As mentioned above, when according to the difference between drum use amount monitoring threshold voltage V0 and the detection voltage time, carry out the control of the conversion of charging AC voltage, might suitable charging AC voltage be set according to the drum use amount thereby become.

Incidentally, as shown in Figure 9, in preceding rotation and back rotation,, the charging biasing can be located at smaller value Vpp-(n+2), Vpp-(n+3) etc. within the scope that does not cause the image failure printing (imaging) before and afterwards.In the present embodiment, respectively charging is biased in when printing and is made as Vpp-2, when preceding rotation, be made as Vpp-4, and when the rotation of back, be made as Vpp-5.As a result, the charging current amount that flows through photosensitive drum further reduces, and the operation lifetime of photosensitive drum is prolonged.

In addition, need not the charging biasing is calculated in each time printing, and can determine the timing of calculating charging biasing according to the information of drum use amount.For example, when reaching predetermined value A or B, the drum use amount calculates the charging biasing.

As mentioned above,, can export the charging bias power supply circuit of two or more AC P-to-P voltages, realize these effects similarly by using other though as an example the time, described the effect of present embodiment with the method for controlling five kinds of P-to-P voltages.Therefore, should be appreciated that such situation is also contained within the scope of the present invention.

Incidentally, except that in installing process cartridge, also can when preheating, carry out determining of charging P-to-P voltage under the charging current detecting pattern.

As mentioned above, according to present embodiment, even in the system of the stack biasing that applies AC and DC with single supercharging device, when installing process cartridge (when the door of the main body of closing imaging device), the AC current sensing means also detects the current value that flows through photosensitive part (drum) under a plurality of AC voltages applying, and an appropriate voltage level is applied as a bias voltage, control this bias voltage by using the information that detects current value.

As a result, become and might carry out charging control, control the caused impedance variation of thickness of proofreading and correct owing to operating environment and photosensitive drum by this charging, and the tolerance limit of charging bias supply.As a result, become and to combine with suitable charging (discharge) control, realize that the cost of power circuit reduces to save with the space.

＜the second embodiment 〉

Present embodiment is characterised in that the timing of determining to detect charging current according to drum use amount (by printer paper number, drum rotational time and apply at least one in the offset time of charging calculate).

With reference to the process flow diagram of Figure 11 and the curve map of Figure 12, with the process of explanation present embodiment.

Shown in Figure 11 process flow diagram, close the door (step S201) of the main body of imaging device, and imaging device is changed to charging current detecting pattern (step S202).Selection is not less than the minimum voltage value Vpp-n of V0, and is stored in the storer 39 of main body of imaging device (step S203)., when drum use amount reach predetermined value (step S207), again imaging device be changed to charging current detecting pattern (step S202), and select minimum voltage value Vpp-n thereafter.For example, when the drum use amount reach respectively the photosensitive drum life-span 20%, 40%, 50%, 60%, 70%, 80%, 85%, 90% and 95% the time, even when imaging equipment is changed to the charging current detecting pattern, also can realize enough effects.

In addition, shown in Figure 12 curve map, the interval of the conversion of charging biasing is quite long, so need not to monitor continuously charging current value.As a result, for charging biasing conversion, it is enough detecting charging current value by about 1/10 the interval in drum life-span.In addition, at the later stage (continuous imaging) of the use of photosensitive drum, the thickness of photosensitive drum is easier to reduce, thereby is easy to the increase of accelerated charging electric current.For this reason, if be shown in the stage early of total bulging use amount (continuous imaging) with at interval long as D1 or D2, and be shown in thereafter stage phase with the short detection of carrying out charging current at interval as D5 or D6, just imaging device over and over again must be changed to the charging current detecting pattern, thereby cause the short printing stand-by period.

＜the three embodiment 〉

Present embodiment is characterised in that having a handle box C as the storer 10 of memory storage with one is removably mounted on the main body 20 of imaging device; By in storer 10, storing the information of the use amount of photosensitive drum in advance, and in storage medium the information of the threshold value of accumulator drum use amount in advance, with timing as the charging AC P-to-P voltage pp of the individual characteristic of selecting to be suitable for used handle box, information with threshold voltage, (this value is identical with starting voltage among first embodiment with controlling charging AC P-to-P voltage to select according to the drum use amount, and be called " charging Vpp selection/control threshold value " in the present embodiment), adapt to the poor individually of used handle box; And the control of carrying out the charging biasing in this manner, so that by the AC P-to-P voltage being vibrated detect the charging AC electric current that flows through photosensitive drum 1, and with one for the minimum and pairing detection bias voltage of detection current value that is not less than threshold current value as the charging bias voltage.

Those characteristics that comprise other characteristics of the layout of imaging device and operation, printer operation order and charging biasing production method and first embodiment are similar, and the descriptions thereof are omitted.

The charging control of the canned data of the use handle box that constitutes the present embodiment feature will be described in detail.

Confirmed to be used for the charging Vpp selection/control threshold value (threshold voltage) of charging control of the present invention,, be subjected to the influence of characteristic variations especially according to the mode of operation of charging roller 2 with the characteristic and the operational state change of each used device of handle box.

More specifically, use charging roller, when small toner particle was attached on the charging roller surface, the roller surface was easy to have surface heterogeneity, thereby was arranged on a kind of state that is imbued with fine discharge electrode part.As a result, using under the charging roller,, become less so confirmed can not cause the minimum AC peak one peak voltage (charging Vpp selection/control threshold value) of charging scrambling because charging roller is easy to cause inhomogeneous discharge.

Therefore, in the present embodiment, as shown in figure 17, storer 10 has the memory block that is used to store following message.

(1) storage is determined the information of coefficient of arithmetic expression of the data of drum use amount according to the characteristic of photosensitive drum 1 and charging roller 2 in storer 10.

(2) the charging biasing application time of measuring according to imaging equipment body, driving (operation) time and the coefficient information of photosensitive drum 1 are calculated drum use amount (information), then from the main body side write store.

(3) in storer storage according to the information of the timing (threshold value) of the main bulging use amount of determining of the impedance operator of charging roller institute and the information of the Vpp selection/control threshold value (threshold voltage) of charging.

Engine controller 37 is carried out the Card read/write operation with storer 10, and storer 10 is as the memory storage of handle box C side.According to information (2) and (3), engine controller 37 is carried out such control, so that make the vibration of AC P-to-P voltage, flow through the charging AC electric current (as magnitude of voltage) of sub-image load bearing component with detection, and with AC P-to-P voltage and charging Vpp selection/control threshold ratio, determining that is not less than charging Vpp a selections/control threshold value, and provide the AC P-to-P voltage of minimum detection current value, the charging when the being used as imaging AC voltage of setovering.

In storer 10, storing various information.In the present embodiment, in storer 10 storage comprise at least bulging use amount arithmetic expression coefficient φ, drum use amount timing (threshold value) Tc and to the information of inductive charging Vpp selection/control threshold value (threshold voltage) V0 and V1.These threshold values and coefficient for example with the susceptibility of photosensitive drum and material, in the characteristic variations of the thickness and the charging roller 2 of photosensitive drum production period, and when producing handle box, with itself and the corresponding value write store of characteristic separately, as characteristic information about photosensitive drum 1.In addition, these canned datas always are changed to such state, so that they can transmit and receive for main body controller 38.According to these information, carry out arithmetical operation, and carry out data verification by controller 38.

Drum use amount data computing method in the present embodiment will be described.

In controller (arithmetic operating apparatus) 38, carry out the arithmetical operation of drum use amount D according to reduction formula D=A+B * φ, the A integrated value of biasing application time data of representing to charge wherein, B represents the integrated value of photosensitive drum rotational time data, and φ represents to be stored in the weighting coefficient in the storer 10 of handle box C.Any time when incidentally, the arithmetical operation of rousing the use amount data can stop in the driving of photosensitive drum 1 carries out.

Secondly, will the process of determining of charging biasing in the present embodiment be described with reference to the process flow diagram of Figure 13 and Figure 14.

The operation of imaging device begins (START).

＜step 〉

S301: the power supply of connecting the main body of imaging device.Preceding rotation beginning.

S302: controller 38 is read bulging use amount data D from the storer 10 of handle box C, the arithmetic expression coefficient φ (being used to carry out the arithmetical operation of bulging use amount) of drum use amount data, charging Vpp selection/control threshold information V0 and V1, and drum use amount timing (threshold value) information Tc-1.

S303: relatively rouse use amount data D and Tc-1.

S304: when D＜Tc-1, with V0 as charging Vpp selection/control threshold value (threshold voltage).

S305: as D〉during Tc-1, with V1 as charging Vpp selection/control threshold value.

S306:, detect charging current I-n by applying a charging P-to-P voltage Vpp-n.Voltage application is according to Vpp-1, Vpp-2 ..., Vpp-5 (carry out by the order of Vpp-1＞Vpp-2＞Vpp-3＞Vpp-4＞Vpp-5).

S307: will carry out voltage transitions the detection voltage Vn that obtains and the Vpp selection/control threshold value (threshold voltage) of charging to charging current and compare.

S308: will at first satisfy Vn〉the charging P-to-P voltage (minimum and be not less than charging Vpp selection/control threshold value) of charging Vpp selections/control threshold value is chosen as to charge and setovers.If Vn＜charging Vpp selection/control threshold value, step S306 is returned in operation.

S309: upgrade the bulging use amount data D that stores in the storer 10 of handle box C.

S310: imaging device is changed to stand-by state.

Figure 14 is illustrated in the process flow diagram that the charging biasing applies when printing.The precedence diagram and first embodiment that this charging biasing applies are same, and are shown in Fig. 9.

＜step 〉

S401: imaging device is changed to stand-by state.

S402: slave controller 38 sends a print start signal.

S403: controller 38 is read bulging use amount data D from the storer 10 of handle box C, the arithmetic expression coefficient φ (being used to carry out the arithmetical operation of bulging use amount) of drum use amount data, charging Vpp selection/control threshold information V0 and V1, and drum use amount timing (threshold value) information Tc-1.

S404: relatively rouse use amount data D and Tc-1.

S405: when D＜Tc-1, with V0 as charging Vpp selection/control threshold value (threshold voltage).

S406: when D 〉=Tc-1, with V1 as charging Vpp selection/control threshold value.

S407: during preceding rotation, apply a P-to-P voltage Vpp (n+1), it is chosen as the little one-level of charging P-to-P voltage Vpp (minimum and be not less than charging Vpp selections/control threshold value) of charging biasing during than imaging, with detection charging current I-(n+1).

S408: will compare by detecting charging current I-(n+1) voltage transitions the output voltage V n+1 that obtains and the Vpp selection/control threshold value (threshold voltage) of charging.

S409: when Vn+1＜charging Vpp selection/control threshold value, apply Vpp-n, the charging biasing during as imaging.

S410: when Vn+1 〉=charging Vpp selection/control threshold value, apply Vpp-(n+1), the charging biasing during as imaging.

S411, S412: judge whether printing continues.

S413: back rotation beginning.Vpp-min is applied as the charging biasing.

S414: upgrade the bulging use amount data D that stores in the storer 10 of handle box C.

S401: imaging device is changed to stand-by state.

Control according to the charging that above-mentioned process flow diagram is carried out in the present embodiment.

The effect of present embodiment is below described.

(1) to the influence of the output tolerance limit of the P-to-P voltage of operating environment and equipment body

Similar with first embodiment, according to present embodiment, even operating environment changes, or the output valve of P-to-P voltage changes use charging current detecting pattern when installing process cartridge between the upper and lower bound of the tolerance limit of power circuit.As a result, can determine charging AC voltage Vpp, so excessively the AC electric current can not flow through photosensitive drum, thereby allow suitable charging biasing to select, and do not cause charge fault according to photosensitive drum.

In addition, similar with first embodiment, equally in the present embodiment, being provided with can be from the minimum value Vpp-min within the output area of the available P-to-P voltages of AC vibration output 31 outputs, with with respect to the predetermined dc voltage Vdc ' that does not cause fault, satisfy relation: Vpp-min 〉=2 * | Vdc ' |, so even causing under the HT/HH environment of less AC P-to-P voltage, also minimum P-to-P voltage Vpp-min is made as and is not less than 2 * | Vdc ' |.As a result, might export the AC P-to-P voltage, it can make photosensitive drum charge equably, and irrelevant with operating environment.

(2) to the influence of the fluctuation of print paper number

As shown in figure 15, the AC current value increases with the printer paper number of photosensitive drum.This is attributable to because the impedance that the abrasion (wearing and tearing) on photosensitive drum surface cause reduces.In addition, as mentioned above, charging Vpp selection/control threshold value changes with characteristic variations according to the mode of operation of charging roller 2.

With reference to Figure 15, Vpp-2 is set, and, after detecting, Vpp-2 is chosen as printing and setovers in the starting stage that monitors Vn.When printing, during preceding rotation, V3 (the detection voltage when applying Vpp-3) and charging Vpp selection/control threshold value V0 are compared.

Thereafter, when the drum use amount reached Tc-1, the Vpp selection/control threshold value of will charging became V1 from V0.

At this moment, during the preceding rotation of printing, compare V3 and charging Vpp selection/control threshold value V1.As a result, satisfy V3 〉=V1, thereby the charging P-to-P voltage Vpp when selecting Vpp-3 as imaging.

Then, during preceding rotation, compare V4 (at the detection voltage that applies under the Vpp-4) and charging Vpp selection/control threshold value V1.When V4 〉=V1, the charging P-to-P voltage Vpp when selecting Vpp-4 as imaging.

Therefore, about the output valve of the charging AC P-to-P voltage of the main body of imaging device, under the situation of operating environment fluctuation,, can carry out suitable charging and control at the impedance of handle box and the scrambling of the caused power-supply tolerance of continuous imaging.

In the present embodiment, by (threshold value of photosensitive drum use amount) information of storage timing in advance in storage medium, to be suitable for the charging AC P-to-P voltage of the individual characteristic of used handle box as selection, with charging Vpp selection/control threshold value (threshold voltage) information, adapt to indivedual differences (especially in regard to the impedance operator of charging roller), and detect the charging AC electric current that flows through photosensitive drum 1 by the vibration that utilizes the AC P-to-P voltage, and with a charging AC P-to-P voltage of detection voltage that provides minimum and be not less than threshold value the charging biasing AC voltage during as imaging, carry out charging biasing control.As a result, might carry out suitable charging biasing control according to the information of the individual characteristic of the used handle box of storage in the storer 10.

In the present embodiment, the value V0 and the V1 of storage conduct charging Vpp selection/control threshold value (starting voltage information) information in the storer of handle box, and the value Tc-1 of timing (threshold value) information of conduct drum use amount.Yet these values can become appropriate value according to the box characteristic.

As mentioned above,, can export the charging bias power supply circuit of two or more AC P-to-P voltages, realize these effects similarly by using other though as an example the time, described the effect of present embodiment with the method for controlling five kinds of P-to-P voltages.Therefore, should be appreciated that such situation is also contained within the scope of the present invention.

Incidentally, except that the time of installing process cartridge, also can when preheating, carry out determining of charging P-to-P voltage under the charging current detecting pattern.

As mentioned above, according to present embodiment, even in the system of the stack biasing that applies AC and DC with single supercharging device, when installing process cartridge (when the door of the main body of closing imaging device), the AC current sensing means also detects the current value that flows through photosensitive part (drum) under a plurality of AC voltages applying, and an appropriate voltage level is applied as a bias voltage, control this bias voltage by using the information that detects current value.

As a result, become and might carry out charging control, control the caused impedance variation of thickness of proofreading and correct owing to operating environment and photosensitive drum by this charging, and the tolerance limit of charge power supply.As a result, become and to combine with suitable charging (discharge) control, realize that the cost of power circuit reduces to save with the space.

＜other 〉

1) shape of contact charging parts 2 is not limited to roll forming.And can for example be endless belt shape.In addition, except that charging roller, the contact charging parts can also be got the form of banister brush, felt, cloth and use.Also may provide suitable elasticity (flexibility) and electric conductivity to charging unit 2 by layering.In addition, charging unit 2 can be altered to charging blade, magnetic brush type charging unit etc.

2) exposure device that is used to form electrostatic latent image is not limited to form with digital form the laser beam flying exposure device 21 of sub-image, and can be other devices, for example common simulation image exposing apparatus and comprise the light-emitting device of LED.Might use any device that can form the electrostatic latent image corresponding with view data, for example light-emitting device, have the combination of such fluorescent light of liquid crystal shutter.

3) sub-image load bearing component 1 for example can be an electrostatic recording dielectric.In this case, the surface of dielectric is predetermined polarity and predetermined potential by initial uniform charging, spends charge devices then, for example goes electric charge syringe needle or electron gun selectively to remove electric charge, thereby forms the target electrostatic latent image by writing.

4) developing apparatus 5 that is used for the foregoing description is reverse development formula, but is not limited thereto.Can also use normal development formula developing apparatus.

Usually, the development method of electrostatic latent image roughly can be divided into four types: single component noncontact development method, wherein with blade etc. toner is coated in developer bearing part for example on the sleeve for nonmagnetic toner, or for magnetic color tuner the effect with magnetic force is coated on the developer bearing part, and toner is carried under contactless state and is coated on the image bearing member, with developing electrostatic latent image; Single component contact development method, wherein the toner that will be coated in the above described manner on the developer bearing part is coated on the image bearing member under contact condition, with developing electrostatic latent image; Bi-component contact development method is wherein prepared a kind of two-component developing agent by toner particle and a kind of magnetic carrier are mixed mutually, and this two-component developing agent is coated on the image bearing member under contact condition, with developing electrostatic latent image; With bi-component noncontact development method, wherein two-component developing agent is coated on the image bearing member under contactless state, with developing electrostatic latent image.For the present invention, available this development method of four types.

5) transfer device 22 is not limited to transfer roll, and can change to the transfer device that uses belt, corona discharge etc.In addition, also may use an intermediate transfer element (parts of an interim transfer printing), for example transfer drum or transfer belt with except that monochrome image, are used for a kind of imaging device that forms polychrome or full-colour image by multiple transfer operation.

6) as for the waveform of the AC component of voltage that is applied to the biasing on charging unit 2 or the developer bearing part 7 (being that the AC component is the voltage with cycle variation magnitude of voltage), might adopt sine wave, square wave and triangular wave.In addition, AC voltage can comprise a kind of by switching on and off the square wave that the DC power supply forms periodically.

As mentioned above, according to the present invention, about a kind of imaging device, it comprises removable sub-image load bearing component and the charging device that contacts with the sub-image load bearing component, then become and not only to realize good charging control, and realize that the space saving and the cost of power circuit reduce.

In addition, the invention is not restricted to the foregoing description, and can realize various changes and change within the scope of the present invention.

Claims (24)

1. imaging device comprises:

An image bearing member,

A charging unit is used for described image bearing member charging,

Voltage output device can apply a plurality of alternating voltages with varying level to described charging unit,

A storer is used to store the information that is used for selecting one of described a plurality of alternating voltages,

Pick-up unit, when from described voltage output device during to described charging unit output AC voltage, be used to detect the electric current that flows through described image bearing member and

Control device, according to the described information that is used for selecting one of described a plurality of alternating voltages of storing in the described storer, the detected value of the electric current that detects with described pick-up unit is used to determine during imaging from the alternating voltage of described voltage output device to described charging unit output.

2. according to the equipment of claim 1, the described information that wherein is used for selecting one of described a plurality of alternating voltages is a relevant information that is used for determining to the threshold value of the alternating voltage of described image bearing member charging.

3. according to the equipment of claim 2, wherein when from described voltage output device when described charging unit is exported described a plurality of alternating voltage, the described threshold of storing in a plurality of detected values that described control device detects described pick-up unit and the described storer, to determine the minimum alternating voltage of corresponding with described detected value described a plurality of alternating voltages of exporting from described voltage output device, as the alternating voltage of exporting to described charging unit from described voltage output device during imaging, described minimum alternating voltage is not less than described threshold value.

4. according to the equipment of claim 1, wherein said storer is also stored the information of the use amount of relevant described image bearing member, and described control device is determined the alternating voltage of exporting to described charging unit from described voltage output device according to selecting the described information of one of described a plurality of alternating voltages with corresponding being used for of described information of relevant described use amount during imaging.

5. according to the equipment of claim 1, wherein said storer is also stored the information of the use amount of relevant described image bearing member, and when the described use amount of described image bearing member reached a predetermined value, described control device was carried out the control of determining alternating voltage.

6. according to the equipment of claim 1, wherein supply with a superimposed voltage that comprises AC voltage and dc voltage to described charging unit, and be applied to the twice of the minimum voltage value of a plurality of alternating voltages on the described charging unit greater than dc voltage from described voltage output device.

7. according to the equipment of claim 1, it is removably installed a handle box, this handle box comprises described image bearing member, described charging unit and described storer, and they are integrally supported to form a unit.

8. according to the equipment of claim 7, wherein this handle box also comprises any one of a developing parts and a cleaning member, the electrostatic latent image that described developing parts is used to develop and forms on the described image bearing member, described cleaning member is used to clear up the developer on the described image bearing member.

9. according to the equipment of claim 1, wherein said storer is also stored the information of the use of relevant described image bearing member, and described information according to the use of relevant described image bearing member, and when applying determined alternating voltage by detected value that described pick-up unit detected and when applying than the little alternating voltage of determined alternating voltage by the difference between the detected value that described pick-up unit detected, described control device is controlled the alternating voltage to described charging unit output during imaging.

10. handle box comprises:

An image bearing member,

A charging unit, be used for to the charging of described image bearing member and

A storage medium, the information that is used to store relevant described handle box,

Wherein can supply with a plurality of alternating voltages to described charging unit with varying level, and

Described storage medium has a memory block that is used to store the information that is used for selecting one of described a plurality of alternating voltages.

11. according to the handle box of claim 10, the described information that wherein is used for selecting one of described a plurality of alternating voltages is a relevant information that is used to determine be applied to the threshold value of the alternating voltage on the described charging unit.

12. according to the handle box of claim 10, wherein said storage medium also has the memory block of the information of a use amount that is used to store relevant described image bearing member.

13. according to the handle box of claim 12, wherein said storage medium also has a memory block that is used to store the information of relevant arithmetic efficient, with the arithmetical operation of the described use amount of carrying out described image bearing member.

14. handle box according to claim 10, also comprise any one of a developing parts and a cleaning member, the electrostatic latent image that described developing parts is used to develop and forms on the described image bearing member, described cleaning member is used to clear up the developer on the described image bearing member.

15. storage medium, be installed on the handle box, this handle box is removably mounted on the imaging device, and this handle box comprises an image bearing member and a charging unit that is used for described image bearing member charging, wherein can supply with a plurality of alternating voltages to described charging unit with varying level, and

Described storage medium comprises:

A memory block that is used to store the information that is used for selecting one of described a plurality of alternating voltages,

The described information that wherein is used for selecting one of described a plurality of alternating voltages is the information that is used to determine being applied to the alternating voltage on the described charging unit during the imaging, and assigns to determine by the control part of described imaging device.

16. according to the storage medium of claim 15, the described information that wherein is used for selecting one of described a plurality of alternating voltages is a relevant information that is used to determine be applied to the threshold value of the alternating voltage on the described charging unit.

17., also have the memory block of the information of a use amount that is used to store relevant described image bearing member according to the storage medium of claim 15.

18. according to the storage medium of claim 17, also have a memory block that is used to store the information of relevant arithmetic efficient, with the arithmetical operation of the described use amount of carrying out described image bearing member.

19. storage medium according to claim 15, wherein said box also comprises any one of a developing parts and a cleaning member, the electrostatic latent image that described developing parts is used to develop and forms on the described image bearing member, described cleaning member is used to clear up the developer on the described image bearing member.

20. control system, be used to control a kind of imaging device that comprises an apparatus body and a handle box, wherein said imaging device comprises an image bearing member, a charging unit that is used for described image bearing member charging, can apply the voltage output device of a plurality of alternating voltages to described charging unit with varying level, with when from described voltage output device during to described charging unit output AC voltage, be used to detect the pick-up unit of the electric current that flows through described image bearing member, and wherein said control system comprises a storage medium, be installed on the described box, has a memory block that is used to store the information that is used for selecting one of described a plurality of alternating voltages, and control device, according to the described information that is used for selecting one of described a plurality of alternating voltages of storing in the described storer, the detected value of the electric current that detects with described pick-up unit is used to determine during imaging from the alternating voltage of described voltage output device to described charging unit output.

21., wherein be used for selecting the described information of one of described a plurality of alternating voltages, be a relevant information that is used for determining to the threshold value of the alternating voltage of described image bearing member charging according to the system of claim 20.

22. according to the system of claim 21, wherein said voltage output device can be exported a plurality of alternating voltages to described charging unit; And when from described voltage output device when described charging unit is exported described a plurality of alternating voltage, the described threshold that described control device is stored a plurality of detected values that described pick-up unit detected and described storage medium, to determine the minimum alternating voltage of corresponding with described detected value described a plurality of alternating voltages of exporting from described voltage output device, as the alternating voltage of exporting to described charging unit from described voltage output device during imaging, described minimum alternating voltage is not less than described threshold value.

23. system according to claim 20, wherein said storage medium also has a memory block that is used to store the information of described a plurality of alternating voltages, memory block with the information of a use amount that is used to store relevant described image bearing member, and described control device is according to the described information of relevant described use amount, be used for selecting the described information of one of described a plurality of alternating voltages by conversion, determine during imaging from the alternating voltage of described voltage output device to described charging unit output.

24. system according to claim 20, wherein this handle box also comprises any one of a developing parts and a cleaning member, the electrostatic latent image that described developing parts is used to develop and forms on the described image bearing member, described cleaning member is used to clear up the developer on the described image bearing member.

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