CN1841227A - Image forming apparatus - Google Patents
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- CN1841227A CN1841227A CN 200610065997 CN200610065997A CN1841227A CN 1841227 A CN1841227 A CN 1841227A CN 200610065997 CN200610065997 CN 200610065997 CN 200610065997 A CN200610065997 A CN 200610065997A CN 1841227 A CN1841227 A CN 1841227A
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Abstract
An image forming apparatus including a photoreceptor that rotates, a charging member provided in contact with or in close proximity of the photoreceptor to charge the photoreceptor, a charge amount detecting portion that accumulates current flowing across the photoreceptor to obtain a charge amount of the photoreceptor, while the current is being applied from the charging member until a voltage on a surface of the photoreceptor substantially corresponds to the voltage applied by the charging member, and a controller that calculates a film thickness of the photoreceptor based on the charge amount.
Description
Technical field
The present invention relates to a kind of image processing system, wherein apply AC bias voltage and DC bias voltage, thereby equably photoreceptor is charged with contact charging method or next-door neighbour's charging method, relate more specifically to a kind of measuring technique of thickness of photoreceptor with discharge operation principle.
Background technology
Various assemblies such as charging roller, develop brush (brash) and transfer roll, cleaning brush, cleaning doctor etc. contact with the surface physics of the photoreceptor of image processing system.Along with image formation is repeatedly handled, this physics contact is worn and torn the surface of photoconductive layer gradually.Particularly, the size of the force of sliding friction that is applied by cleaning brush or cleaning doctor is enough big and cause photoconductive layer to wear and tear.
Because above-mentioned wearing and tearing are a certain amount of if the thickness of photoconductive layer reduces, then remarkable degeneration of photonasty meeting or charge characteristic can deteriorations.This makes and can not be charged equably in the surface of photoreceptor with the current potential of expectation, thereby can not form distinct image.
Therefore, as time goes by the thickness of the photoconductive layer of photoreceptor is measured, to estimate the serviceable life of photoreceptor.
Japanese Patent Application No.59-69774 (hereinafter referred to as document 1) has described described measuring technique.After photoreceptor is charged, by detector two current potentials on the photosensitive surface are measured immediately, have the surface voltage V0 of dark decay characteristic with calculating.Then, in the computing formula below, come the thickness L of measuring light conducting shell by the electric current I of this surface voltage V0 and per unit discharge length.
I＝(ε/L)·v·V0
Here, ε represents the specific inductive capacity of photoreceptor, and v represents the movement velocity of photoreceptor.
Japanese Patent Application Publication No.5-223513 (hereinafter referred to as document 2) has also described described measuring technique.Provide two the voltage V1 and the V2 of the voltage that is equal to or greater than when beginning to discharge respectively to charging roller, to measure electric current I 1 and I2.Calculate the gradient of V-I characteristic by (I2-I1)/(V2-V1).At this moment, come calculated thickness d by following equation.
The gradient of V-I characteristic=ε LVp/d (first method)
Here, Vp represents processing speed, and ε represents the specific inductive capacity of photoreceptor, and L represents effectively to charge width.As prerequisite, V2-V1 needs the presentation surface potential difference (PD).
I=ε LVpVd/d (second method)
Japanese Patent Application No.9-101654 (hereinafter referred to as document 3) described when by charging roller once more when eliminating lamp and eliminated the surperficial uniform charging of photoreceptor of electric charge by electric charge, measure the DC current of the charging roller that between photoreceptor and charging roller, charges.Can shown in first phenomenon among Fig. 1 of document 3, detect the thickness of photoconductive layer.
Yet, in document 1 to 3 disclosed measuring technique,, still use this electric current I to measure thickness although the electric current I of the photoreceptor of flowing through comprises leakage current.Therefore, the thickness that can go out by above-mentioned Equation for Calculating is relatively poor aspect the accuracy of detection.In addition, eliminated the electricity on the photoreceptor even electric charge is eliminated lamp, but the surface potential of photoreceptor can not be reduced to 0V.The problem that this electric current I that causes recording like this changes.In addition, detect in the method for thickness, measure DC current to estimate thickness in the flow through electric current I of photoreceptor of use.If the defective (for example, pin hole etc.) that exists or occur causing because of low breakdown voltage then flows in this defective too much with the leakage current that charging has nothing to do, cause incorrect measurement in photoreceptor.Also have another problem, i.e. the variation of processing speed has changed DC current to be measured.
In addition, there is following problem respectively in above-mentioned document 1 to 3.
The problem of document 1 is, because the dark decay characteristic is for environment and unstable, so potential value V0 and the out of true calculated.The movement velocity v of photoreceptor also changes.
The problem of document 2 is, because the resistance of the charging assembly that causes owing to environment or pollute resistance is had a negative impact and resistance is changed, so V2-V1 is not corresponding with the surface electrical potential difference.In the second approach, because the influence of the precision of Vp and I, so thickness is unexcellent aspect precision.
Also there are the following problems for document 3.At first, the DC current on the charging roller changes because of environment easily.Direct electric current stream is subjected to the very big influence of the surface state around the high-pressure section.The various dusts that comprise toner powder are attached on the periphery of high-pressure section.High humility has reduced lip-deep resistance, has increased the leakage of DC current, thereby makes the accuracy of detection deterioration of thickness.
In addition, another problem is that the light quantity that electric charge is eliminated lamp can change DC current.Electric charge is set eliminates lamp so that before by charging roller being charged in the surface, the surface potential that makes photoreceptor is an earth potential.The purpose of the electric charge elimination lamp that is provided with like this is to detect afterimage, thereby photoreceptor needn't be exposed under the following high light, and this high light may cause light fatigue and make photoreceptor be in earth potential fully.Therefore, even electric charge is arranged in also common residue after photoreceptor has been eliminated surface potential.This residual charge is eliminated lamp according to electric charge the degeneration of intensity, photoreceptor is with environment and different.Therefore, when charging roller charged to photoreceptor once more, DC current was always not identical.This makes the accuracy of detection deterioration of thickness.
In addition, another problem is, can not detect described thickness under the situation that does not have electric charge elimination lamp.Picture quality is not had in the device of adverse effect at afterimage, electric charge is not set eliminates lamp.In these cases, DC current can not flow through charging roller.Therefore, can not calculate described thickness.
Summary of the invention
According to an aspect of the present invention, provide a kind of image processing system, it comprises: the photoreceptor of rotation; Charging assembly, it is configured to contact or be close to described photoreceptor, so that described photoreceptor is charged; Quantity of electric charge test section, it is when described charging assembly applies electric current, accumulative total is flowed through the electric current of described photoreceptor obtaining the quantity of electric charge of described photoreceptor, up to the voltage on the described photosensitive surface basically with till the voltage that is applied by described charging assembly is corresponding; And controller, it calculates the thickness of described photoreceptor according to the described quantity of electric charge.According to the present invention, detect thickness by obtaining surface potential up to the photoreceptor quantity of electric charge till saturated, thereby make it possible to accurately detect the thickness of photoreceptor and can not be subjected to the resistance of charging assembly or the influence of pollution or environmental change.Therefore, can detect the serviceable life of the photoreceptor that reduces because of thickness.In addition, this also is useful for is provided to photoreceptor longer serviceable life.
According to a further aspect in the invention, provide a kind of image processing system, it comprises: the photoreceptor of rotation; Charging assembly, it is configured to contact or be close to described photoreceptor, so that described photoreceptor is charged; Quantity of electric charge test section, it is when discharging to the photoreceptor that has charged, accumulative total is flowed through the electric current of described photoreceptor obtaining the quantity of electric charge of described photoreceptor, up to the voltage on the described photosensitive surface basically with till ground level is corresponding; And controller, it calculates the thickness of described photoreceptor according to the described quantity of electric charge.
According to a further aspect in the invention, provide a kind of image processing system, it comprises: the photoreceptor of rotation; Charging assembly, it is configured to contact or be close to described photoreceptor, so that described photoreceptor is charged; Capacitor with known capacitance, itself and described charging assembly are connected in parallel; Current detection component, it detects first magnitude of current and second magnitude of current, and this first magnitude of current flows in the described capacitor, and this second magnitude of current is from the described charging assembly described photoreceptor of flowing through; And controller, its ratio according to described first magnitude of current and second magnitude of current detects the electric capacity between described charging assembly and described photoreceptor.According to the present invention, capacitor and charging assembly with known capacitance are connected in parallel, and detect electric capacity between charging assembly and the photoreceptor according to the ratio of the magnitude of current that flows into the magnitude of current in the capacitor and the photoreceptor of flowing through, make it possible to accurately to obtain the electric capacity between charging assembly and the photoreceptor thus, even the voltage waveform of charging assembly is different with ideal waveform.
Description of drawings
To describe exemplary embodiment of the present invention in detail based on the following drawings below, in the accompanying drawing:
Fig. 1 is a curve map of describing conventional art;
Fig. 2 is the view of expression according to the structure of the image processing system of first embodiment of the invention;
Fig. 3 represents the structure of charge detection part;
Fig. 4 represents the relation between the direct current flow of the number of revolutions of photoreceptor, the surface potential of photoreceptor and the photoreceptor of flowing through;
Fig. 5 represents the number of revolutions of photoreceptor and the relation between the DC current;
Fig. 6 is the view of expression according to the structure of the image processing system of second embodiment of the invention;
Fig. 7 represents the structure of photoreceptor unit;
Fig. 8 represents the off-centre of photoreceptor and charging roller;
Fig. 9 represents how the distance between photosensitive drums and the charging roller changes with eccentric;
Figure 10 to Figure 12 represents the structure of rectification circuit and low-pass filter;
Figure 13 is illustrated in the structure according to the funtion part of the detection quantity of electric charge in the image processing system of third embodiment of the invention;
Figure 14 is the process flow diagram of expression according to the operating process of third embodiment of the invention; And
Figure 15 is the view of the structure of expression analog integrator circuit.
Embodiment
Provide description below with reference to accompanying drawings to exemplary embodiment of the present invention.
(first exemplary embodiment)
With reference to Fig. 2, will provide description now to the present invention's first exemplary embodiment.Photoreceptor 2 as image holder is the OPC photoreceptors with bulging shape.Photoreceptor 2 is the center with its central shaft perpendicular to paper, with given processing speed (that is peripheral speed) (as shown by arrows) rotation along clockwise direction.
Outer periphery at photoreceptor 2 is equipped with the charging roller 3 that contacts with photoreceptor 2, grating optical scanner (ROS) 4, developing apparatus 5, cleaning doctor 7 and the electric charge as exposure device eliminated lamp 8.
Subsequently, shine (with the form of scan exposure) to the outside surface to be charged of the photoreceptor 2 of such rotation from the laser beam of ROS 4 output modulation images and with it.The potential decay of exposed portion also forms electrostatic latent image.
When sub-image arrives the developing location relative with developing apparatus 5 according to the rotation of photoreceptor 2, provide the toner that fills negative electricity from developing apparatus 5, and generate toner image by discharged-area development.
In the downstream of developing apparatus 5, when when the sense of rotation of photoreceptor 2 is seen, be provided with the conduction transfer roll 6 that contacts with photoreceptor 2 pressure, and the occlusion portion of photoreceptor 2 and transfer roll 6 constitutes transfer section.
When the toner image that generates arrives above-mentioned transfer section according to the rotation of photoreceptor 2, provide paper to transfer position with synchronous timing on the surface of photoreceptor 2.Simultaneously, apply given voltage to transfer roll 6, thus with toner image from the surface transfer of photoreceptor 2 to paper.
Will be in the transfer position transfer printing paper input fixing device 9 of toner image, with toner image on the surface of paper, export from image processing system then.
Simultaneously, will after transfer printing, brush by photoreceptor 2 lip-deep remaining toners by cleaning doctor 7.The surface of photoreceptor 2 is cleaned to carry out the processing of image formation next time.Eliminate lamp 8 by electric charge and remove electrostatic latent image.
According to this exemplary embodiment, also be provided with power supply 10, charge detection part 11 and controller 12.Power supply 10 provides the voltage that generates by stack AC voltage on dc voltage to charging roller 3.Charge detection part 11 detects the quantity of electric charge that is charged on the photoreceptor 2.Controller 12 is controlled the voltage that provides from power supply 10 according to the quantity of electric charge that is detected by charge detection part 11.
Fig. 3 represents the structure of charge detection part 11.Charge detection part 11 comprises current-voltage transfer resistance device 21, polarity controller 22 and totalizer 23.Polarity controller 22 changes the polarity of the voltage that imposes on the counting circuit in the totalizer 23.Totalizer 23 detects the quantity of electric charge that is charged on the photoreceptor 2.Totalizer 23 comprises operational amplifier 24, capacitor 25 and switch 26, as shown in Figure 3.
The processing of calculating thickness d according to by the charge detection part 11 detected quantities of electric charge will be described below.Calculate thickness d by following expression.
D=ε effective charge length photoreceptor diameter π V/Q (wherein, Q represents the quantity of electric charge, and V represents the voltage that applied)
As can be seen from above-mentioned expression formula, the every constant that is except Q and V.Therefore, can detect thickness with the precision higher than conventional art.Hereinafter, the thickness of photoreceptor 2 is represented the outermost thickness of photoreceptor 2.
Below the method that detects the electric charge on the photosensitive surface by charge detection part 11 will be described.Fig. 4 represents when the surface potential and the DC current that apply when having the AC voltage that is enough to the level that charged in this surface and dc voltage.Transverse axis is represented the number of revolutions of photoreceptor.As dc voltage, when rotating for the first time, apply-750V.Apply after this dc voltage charging potential approaching immediately-750V, but still unsaturation.Need twice or rotation more frequently reach capacity (reach-750V).Only flow through and the corresponding DC electric current of charging potential difference.Therefore, if as measuring thickness after the rotation for the first time as described in the document 2, and apply like this-dc voltage of 750V causes on photosensitive surface-700V, then has the difference as the 50V of detection error.In addition, because the current potential after the rotation for the first time changes according to the pollution of the thickness of photoreceptor, environment, charging assembly, so can not proofread and correct by corrected value.On the contrary, according to the present invention, when charging potential is corresponding with dc voltage, just detect charging potential.Therefore, can accurately calculate thickness, and not be subjected to the influence of above-mentioned error.
To describe below and how handle leakage current.The electric current that flows through photosensitive drums 2 is little of tens μ A.Therefore, must consider the influence of leakage current.In fact, there is the leakage current of about 1 μ A, the error of about 10% in causing detecting.In conventional art, ignored the influence of leakage current.Leakage current comprises the leakage relevant with electric current of not depending on magnitude of voltage and depends on the leakage relevant with resistance of magnitude of voltage.
DC electric current when Fig. 5 represents rotating each time of photosensitive drums 2.Rotation in the number of revolutions 2 of photoreceptor 2 regularly applies signal.When the number of revolutions 1 of photoreceptor 2, flow through the leakage relevant with electric current.In number of revolutions 2, the charging current of comprise the leakage relevant, the relevant leakage with resistance of the resistive element of flowing through and helping being charged with electric current.Number of revolutions 5 to 7 o'clock, current potential was saturated and no longer flow through charging current, and only flows through leakage current.
Therefore, can only obtain charging current by the aggregate-value that from the aggregate-value of the electric current of number of revolutions 2 to 4, deducts the electric current of number of revolutions 5 to 7.Carry out the subduction of aggregate-value by the connection that selectively changes polarity controller 22.In number of revolutions 2 to 7 accumulative total electric currents,, realize this subduction by making the signal polarity on the polarity controller 22 opposite in number of revolutions 5 to 7.
According to this exemplary embodiment, in applying the charging process of dc voltage, detect thickness by electric charge.Yet, can under charged state, in discharge process, detect thickness.Also can in exposure process, make photosensitive drums 2 shelf depreciations, and subsequently photosensitive drums 2 be charged, detect the quantity of electric charge and detect local thickness.According to mode same as described above, can detect thickness by shelf depreciation.
[second embodiment]
Various details second exemplary embodiment.Referring now to Fig. 6, for charging roller 3 provides a plurality of power supplys (AC power supplies 31 and DC power supply 32), and these power supplys are connected in parallel with the capacitor 33 with known capacitance.According to electric current that flows through capacitor 33 and the ratio that flows through the electric current of charging roller 3, can obtain the electric capacity between charging roller 3 and the photosensitive drums 2 with known capacitance.More specifically, divider shown in Fig. 6 40 calculates electric current that flows through the capacitor 33 with known capacitance and the ratio that flows through the electric current of charging roller 3, and the electric capacity of itself and capacitor 33 is multiplied each other.
In aforementioned calculation, electric capacity is not imposed on the influence of the output impedance of the AC frequency of charging roller 3 or AC power supplies.Even waveform is not sinusoidal wave, perhaps waveform is rectangle, triangle, or owing to be in given voltage or more high-tension clamping voltage is out of shape, also can apply similar waveform to the capacitor 33 with known capacitance, and can not make measuring accuracy decline.If described in document 3, the specific inductive capacity of photoconductive layer changes according to environment, then can use identical materials to make the dielectric layer of capacitor 33 and photosensitive drums 2 to eliminate described influence.
Effective capacitance between charging roller 3 and the photosensitive drums 2 is determined by the contact area of occlusion portion.The contact area of this occlusion portion is according to photoreceptor and difference.Therefore, even measured electric capacity, the electric capacity of Ce Lianging can not be converted to thickness like this.
Because the off-centre of photosensitive drums 2 and charging roller 3, (that is, occlusion portion) area changes according to rotation, thereby can not obtain accurate thickness by the capacitance when detecting and make contact portion.
Referring now to Fig. 8, photosensitive drums 2 and charging roller 3 off-centre.ω 1 and ω 2 represent the angular velocity of charging roller 3 and photosensitive drums 2 respectively.Can use additive value and the subtraction value of ω 1 and ω 2,, obtain the distance between the center of the center of distance between the surface of the center of charging roller 3 and photoreceptor 2 or charging roller 3 and photosensitive drums 2 by following expression.How the distance that Fig. 9 shows between photosensitive drums 2 and the charging roller 3 changes with eccentric.As shown in Figure 9, waveform has the shape of wherein carrying out the AC modulation by two frequencies.
Cosω1t+Cosω2t＝2Cos((ω1t+ω2t)/2)×Cos((ω1-ω2)/2)
This only shows needs applying from charging roller 3 and the electric current of the photoreceptor 2 of flowing through averaged in the cycle of the difference that is equal to or greater than ω 1 and ω 2, to suppress because the measuring error of the thickness that the distance change causes.In fact, can perhaps, come by making it through the low-pass filter that cutoff frequency fc is higher than its cycle with less error measure thickness by using this cycle to carry out integration.
Figure 10 to Figure 12 represents the structure of rectification circuit 41 and low-pass filter 42.Circuit shown in Figure 10 comprises comparer, and it is as rectification circuit 41, so that comparer switches on and off switch A and B carries out rectification.Low-pass filter 42 is normally used wave filters, and it comprises resistor and capacitor.
[the 3rd embodiment]
To provide the description of the 3rd exemplary embodiment of the present invention now.In the 3rd exemplary embodiment, before detecting the quantity of electric charge, with the control of Electric potentials of photoreceptor for having initial voltage V1.Then, applying voltage to photoreceptor 2, is given voltage V2 with the potential setting with photoreceptor 2.At this moment, the electric current of the photoreceptor 2 of flowing through is added up, calculating the quantity of electric charge, and come calculated thickness according to this quantity of electric charge subsequently.According to this exemplary embodiment, the surface potential V2 after the surface potential V1 before detecting the quantity of electric charge and the detection quantity of electric charge is essential.Therefore, accurately control surface current potential V1 and V2.Before detecting the quantity of electric charge, be the given current potential that is used for true integral with the potential setting of photoreceptor.This makes it possible to accurately calculate the quantity of electric charge and accurately measures thickness.
According to this exemplary embodiment, photoreceptor 2 is that diameter is the aluminium drum of 30mm, and its outside surface is coated with the OPC photoconductive layer.This photoreceptor also comprises charge carrier (carrier) transport layer with 29 μ m thickness that is arranged on the charge generating layer.There is following certain situation, wherein according to service condition residual voltage on photoreceptor 2.Even the photoreceptor 2 that has this residual voltage on it applies the dc voltage of 0V, the current potential of photoreceptor 2 is not 0V yet.If the voltage that is applied when calculating thickness is not equal to the current potential of photoreceptor, then error can appear.The surface potential of photoreceptor for this reason, applies the given voltage rather than the 0V of the negative dc voltage that is equal to or less than tens volts, so that can have given state.This has eliminated the influence of residual voltage.Subsequently, carry out the processing that detects the quantity of electric charge.
By applying the voltage that generates by stack AC voltage on dc voltage to charging roller 3, surface potential V1 is controlled to be surface potential V2 on the photoreceptor 2.At this moment, when applying the surface potential V2 different, obtain surface potential V2 when can be at the surface potential of photoreceptor 2 saturated as dc voltage with surface voltage V1.Be used for saturated predetermined amount of time by whether having passed through by what test obtained, whether the surface potential of determining photoreceptor 2 is saturated to and is enough to have surface potential V2.The above-mentioned time period can be substituted by the number of revolutions of photoreceptor 2.In addition, the DC electric current of the photoreceptor 2 of flowing through is monitored, and can when the DC electric current does not change, determine saturated.Alternatively, can use cheap apparent surface's current potential electrometer to detect and definite surface potential saturated.
By when applying the voltage that generates by stack AC voltage on dc voltage to charging roller 3 and measure the quantity of electric charge, the developer roll of developing apparatus 5 and transfer roll 6 be set at have high resistance.In addition, ROS 4 and electric charge being eliminated lamp 8 is set at and closes (off).In order to set this high resistance, developer roll is mechanically separated with photoreceptor 2 with transfer roll 6.Alternatively, developer roll and transfer roll 6 are constructed with the current potential identical with the photoreceptor 2 that is in electric quick condition.Alternatively, power supply 10 is controlled to be makes electric current can not flow into the photoreceptor 2 from developer roll or transfer roll 6.Controller 12 control aforesaid operations.Yet, flow under the situation of the electric current the photoreceptor 2 from developer roll or transfer roll 6 known, can proofread and correct this electric current after a while.
The structure of Figure 13 presentation function part is wherein carried out integration by the DC electric current to the photoreceptor 2 of flowing through and is calculated the quantity of electric charge, and calculates thickness by the quantity of electric charge of such calculating.Funtion part shown in Figure 13 comprises current-voltage transfer resistance device 43, low-pass filter 42, A/D converter 13 and controller 12.To the flow through current conversion of photoreceptor 2 of current-voltage transfer resistance device 43 is a voltage.Hereinafter, abbreviate low-pass filter 42 as LPF 42.
Comprise AC component on the DC component that is superimposed upon power supply 10 by current-voltage transfer resistance device 43 detected voltages.Therefore, AC frequency decay in LPF 42.In addition, LPF 42 can remove the AC component and reduce sample frequency.According to sampling thheorem, this frequency is constructed to as two double-lengths in the AC cycle of the power supply in sampling period or longer.In this case, can think along with data volume to be sampled increases and increased the load of digital processing.For this reason, thus LPF 42 is set reduces sample frequency to eliminate the AC component.This feasible load that can under the situation that accuracy of detection is reduced, reduce digital processing.
The upper limit in sampling period is constructed to make that precision can not reduce in being used to change the control cycle of dc voltage.If dc voltage changes in 50ms, then the sampling period must be set in the 50ms.Between the thickness detection period, the sampling period can all equate in all cycles.Alternatively, only when having variation, shorten this cycle.
The digital voltage value that controller 12 adds up to be changed by A/D converter 13 is to obtain the quantity of electric charge.In addition, can determine the accumulative total cycle by the number of revolutions of photoreceptor 2 as mentioned above, perhaps can determine the accumulative total cycle when DC electric current does not change in the DC of photoreceptor 2 electric current at monitoring stream.In addition, can adopt cheap apparent surface's current potential electrometer to detect and definite surface potential saturated.
In following formula, use the thickness that calculates photoreceptor by the quantity of electric charge that voltage is added up to obtain.
The thickness d=ε effective charge length photoreceptor diameter π of photoconductive layer | V2-V1|/Q
Q represents the quantity of electric charge, and V1 is illustrated in the dc voltage that imposes on photoreceptor 2 before the detection, and V2 is illustrated in the dc voltage that imposes on photoreceptor 2 when detecting.
Under the situation of known initial film thickness before photoreceptor 2 wearing and tearing, measuring the quantity of electric charge before photoreceptor 2 wearing and tearing is the initial charge amount to be set.Can obtain thickness d according to the ratio of the quantity of electric charge of measuring after initial charge amount and photoreceptor 2 wearing and tearing.
The quantity of electric charge of the thickness d=original depth * initial charge amount/current detection of photoreceptor
In the aforementioned calculation method, need not any parameter item, thereby eliminated the individual difference of photoreceptor 2 or charging roller 3, and make it possible to calculate accurately thickness.
Referring now to Figure 14, the operations according to the instant invention process will be described.At first surface potential is controlled to be and has initial potential V1 (at step S1).Here, apply the voltage that generates by stack AC voltage on dc voltage, and be V1 the potential setting of photoreceptor 2 to charging roller 3.
Then, apply the voltage that generates by stack AC voltage on dc voltage, and the surface potential of photoreceptor 2 is controlled to be has current potential V2 (at step S2) to charging roller 3.At this moment, apply the current potential V2 different as dc voltage with V1.When the surface potential of photoreceptor 2 is saturated, this surface potential is changed into V2.At this moment, the current conversion that will flow through photoreceptor 2 by current-voltage transfer resistance device 43 becomes voltage.Then, change to obtain quantity of electric charge Q (at step S3) by 13 pairs of these voltages of A/D converter.The surface potential V1 and the V2 of the quantity of electric charge Q, effective charge length, photoreceptor diameter and the photoreceptor 2 that obtain are like this composed to above-mentioned expression formula, to obtain the thickness d of photoreceptor 2.
Referring now to Figure 15, can use analog integrator circuit 50 to calculate the quantity of electric charge.This analog integrator circuit 50 is the Perfected process that can not produce integral error, although can cause integral error by the sampling period of digital integration method integration.The electric current of the photoreceptor 2 of flowing through is stored among the capacitor C51 as electric charge, and this quantity of electric charge is converted to voltage and output subsequently.A/D converter 13 carries out the AD conversion of voltage.Switch S 1 and S3 are set optionally to change the sense of current of the capacitor C51 that flows through.Be connected by switch S 1 being changed into be connected with terminal A among Figure 15 and switch S 3 changed into terminal C among Figure 15, the electric current of the photoreceptor 2 of will flowing through is stored among the capacitor C51.On the contrary, can be connected, come in capacitor C51, to reduce the electric current of the photoreceptor 2 of flowing through by switch S 1 being changed into be connected with terminal B among Figure 15 and switch S 3 changed into terminal D among Figure 15.Switch S 2 makes capacitor C51 discharge, and such charge stored is reset to zero.
The operation of the analog integrator circuit 50 shown in Figure 15 will be described below.At first make switch S 2 short circuits so that capacitor C51 discharge is zero thereby the quantity of electric charge is set to.Open switch S 2 then, apply charging voltage to photoreceptor 2, so that surface potential is controlled to be V2 with given current potential V1.At this moment, capacitor C51 storage flow is through the electric charge and the leakage current of the electric current of photoreceptor 2.Then, when the surface potential of photoreceptor 2 is saturated, change switch S 1 and S3.Switch S 1 is connected from being connected with terminal A to change into terminal B, and switch S 3 is connected from being connected with terminal C to change into terminal D.At this moment, current potential is saturated and does not have the electric current photoreceptor 2 of flowing through.Therefore, leakage current flow only.In addition, change the polarity of electric current and electric charge is reduced the amount of leakage current.Changing being connected of switch S 1 and S3, and passing through the surface potential that makes photoreceptor 2 after the saturated time period, can obtain output valve by the electric current of the photoreceptor 2 of flowing through owing to apply voltage to photoreceptor 2.This output valve is used to calculate thickness as the quantity of electric charge that is detected.
Although illustrated and described exemplary embodiments more of the present invention, but it should be appreciated by those skilled in the art, can be without departing from the principles and spirit of the present invention, these exemplary embodiments are made amendment, and scope of the present invention is limited by claims and equivalent thereof.
The application requires the right of priority of Japanese patent application No.2005-095836 that submitted on March 29th, 2005 and the Japanese patent application No.2006-006749 that submitted on January 13rd, 2006, by reference it is incorporated at this.
Claims (12)
1, a kind of image processing system, it comprises:
The photoreceptor of rotation;
Charging assembly, it is set to contact or be close to described photoreceptor, so that described photoreceptor is charged;
Quantity of electric charge test section, it is when described charging assembly applies electric current, accumulative total is flowed through the electric current of described photoreceptor obtaining the quantity of electric charge of described photoreceptor, up to the lip-deep voltage of described photoreceptor basically with till the voltage that is applied by described charging assembly is corresponding; And
Controller, it calculates the thickness of described photoreceptor according to the described quantity of electric charge.
2, image processing system according to claim 1, wherein, when after the surface potential with described photoreceptor is set at initial potential surface potential being charged to given current potential, described quantity of electric charge test section accumulative total is from the flow through electric current of described photoreceptor of described charging assembly.
3, image processing system according to claim 1, wherein,
Electric current when accumulative total described photoreceptor in described quantity of electric charge test section is saturated, and detect the margin of error that causes by leakage current in the described quantity of electric charge; And
Described quantity of electric charge test section deducts the described margin of error from the described quantity of electric charge.
4, image processing system according to claim 1 also comprises exposed portion, and it makes the face exposure of described photoreceptor,
Wherein, described quantity of electric charge test section make the exposure of described photoreceptor by described exposed portion after once more when described charging assembly applies electric current, accumulative total is flowed through the electric current of described photoreceptor obtaining the quantity of electric charge of described photoreceptor, up to the lip-deep voltage of described photoreceptor basically with till the voltage that is applied by described charging assembly is corresponding.
5, image processing system according to claim 1, wherein, when detecting the described quantity of electric charge, described controller will develop partly and transfer section is controlled to be and has high resistance.
6, image processing system according to claim 1, wherein, when obtaining the described quantity of electric charge, described controller cuts out electric charge and eliminates lamp and exposed portion.
7, image processing system according to claim 1, wherein, described quantity of electric charge test section is an analog integrator circuit.
8, image processing system according to claim 1, wherein, described controller multiply by first thickness of described photoreceptor with the ratio of first quantity of electric charge and second quantity of electric charge, calculating second thickness of described photoreceptor,
Described first quantity of electric charge was measured by described quantity of electric charge test section before described photoreceptor wearing and tearing,
Described second quantity of electric charge is measured by described quantity of electric charge test section after described photoreceptor wearing and tearing,
Described first thickness was measured by described quantity of electric charge test section before described photoreceptor wearing and tearing,
Described second thickness is the current thickness after described photoreceptor wearing and tearing.
9, a kind of image processing system, it comprises:
The photoreceptor of rotation;
Charging assembly, it is set to contact or be close to described photoreceptor, so that described photoreceptor is charged;
Quantity of electric charge test section, it is in the described photoreceptor discharge of having charged, accumulative total is flowed through the electric current of described photoreceptor obtaining the quantity of electric charge of described photoreceptor, up to the lip-deep voltage of described photoreceptor basically with till ground level is corresponding; And
Controller, it calculates the thickness of described photoreceptor according to the described quantity of electric charge.
10, a kind of image processing system, it comprises:
The photoreceptor of rotation;
Charging assembly, it is set to contact or be close to described photoreceptor, so that described photoreceptor is charged;
Capacitor with known capacitance, itself and described charging assembly are connected in parallel;
Current detection component, it detects first magnitude of current and second magnitude of current, and this first magnitude of current flow in the described capacitor, and this second magnitude of current is from the described charging assembly described photoreceptor of flowing through; And
Controller, its ratio according to described first magnitude of current and described second magnitude of current detects the electric capacity between described charging assembly and the described photoreceptor.
11, image processing system according to claim 10, also comprise memory portion, it stores first thickness of described photoreceptor and first electric capacity between described photoreceptor and the described charging assembly, this first thickness obtained before using described photoreceptor, this first electric capacity was detected by described controller before using described photoreceptor
Wherein, described controller according to and described first electric capacity carried out described first thickness that multiplies each other and the ratio of second electric capacity between described photoreceptor and the charging assembly, calculate second thickness of described photoreceptor, this second film thickness is the current thickness after using described photoreceptor, and this second electric capacity is detected by described controller after using described photoreceptor.
12, image processing system according to claim 10 also comprises:
Rectifier, it detects and rectification described second magnitude of current; And
Low-pass filter, it makes following frequency cutoff, and this frequency is corresponding with the frequency that is equal to or greater than the rotation difference between described photoreceptor and the described charging assembly.
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| JP2005095836 | 2005-03-29 | ||
| JP2005095836 | 2005-03-29 | ||
| JP2006006749 | 2006-01-13 |
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| CN1841227A true CN1841227A (en) | 2006-10-04 |
| CN100474155C CN100474155C (en) | 2009-04-01 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNB2006100659974A Expired - Fee Related CN100474155C (en) | 2005-03-29 | 2006-03-29 | Image forming apparatus |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101329527B (en) * | 2007-06-22 | 2012-04-18 | 富士施乐株式会社 | Total layer thickness detection apparatus and detection method, charging apparatus and image forming apparatus |
| CN102651796A (en) * | 2011-02-28 | 2012-08-29 | 株式会社理光 | Residual image correcting method of electronic images and electronic image forming device |
| CN107463076A (en) * | 2016-06-02 | 2017-12-12 | 富士施乐株式会社 | Image forming apparatus |
| CN109782555A (en) * | 2017-11-13 | 2019-05-21 | 株式会社理光 | Image forming apparatus, image forming method, storage medium and computer installation |
| CN110058501A (en) * | 2016-06-29 | 2019-07-26 | 柯尼卡美能达株式会社 | Image forming apparatus |
| CN110501884A (en) * | 2018-05-16 | 2019-11-26 | 柯尼卡美能达株式会社 | Image forming apparatus and control method |
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- 2006-03-29 CN CNB2006100659974A patent/CN100474155C/en not_active Expired - Fee Related
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101329527B (en) * | 2007-06-22 | 2012-04-18 | 富士施乐株式会社 | Total layer thickness detection apparatus and detection method, charging apparatus and image forming apparatus |
| CN102651796A (en) * | 2011-02-28 | 2012-08-29 | 株式会社理光 | Residual image correcting method of electronic images and electronic image forming device |
| CN102651796B (en) * | 2011-02-28 | 2014-09-17 | 株式会社理光 | Residual image correcting method of electronic images and electronic image forming device |
| CN107463076A (en) * | 2016-06-02 | 2017-12-12 | 富士施乐株式会社 | Image forming apparatus |
| CN110058501A (en) * | 2016-06-29 | 2019-07-26 | 柯尼卡美能达株式会社 | Image forming apparatus |
| CN109782555A (en) * | 2017-11-13 | 2019-05-21 | 株式会社理光 | Image forming apparatus, image forming method, storage medium and computer installation |
| CN109782555B (en) * | 2017-11-13 | 2021-11-02 | 株式会社理光 | Image forming apparatus, image forming method, storage medium, and computer apparatus |
| CN110501884A (en) * | 2018-05-16 | 2019-11-26 | 柯尼卡美能达株式会社 | Image forming apparatus and control method |
| CN112346312A (en) * | 2019-08-09 | 2021-02-09 | 株式会社理光 | Image forming apparatus with a toner supply device |
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