KR20040069736A - Voltage regulator for picture processor, and voltage controlling method thereof - Google Patents

Abstract

PURPOSE: An apparatus and method for controlling a voltage of a non-contact developing device are provided to maintain charging efficiency and supply of a toner uniform until the toner is used up. CONSTITUTION: The total quantity of printing carried out by a non-contact developing device with respect to the total quantity of toner having one non-magnetic component, contained in a unit toner container, is measured(S2). The measured total quantity of printing is less than a reference printing quantity, a difference between a supply voltage provided to a supply roller and a developing voltage is maintained smaller than a standard voltage difference(S4). When the measured printing quantity reaches the reference printing quantity, the voltage difference is controlled to be larger than the standard voltage difference(S5).

Description

Voltage control device of non-contact developing device and its method {VOLTAGE REGULATOR FOR PICTURE PROCESSOR, AND VOLTAGE CONTROLLING METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage control device for a non-contact developing device and a voltage control method thereof, and more particularly, to a voltage difference between a supply roller and a developing roller based on a printing amount performed by a non-contact developing device equipped with a toner receptor. As a voltage control device and a voltage control method thereof, a non-contact developing device using toner technology, for example, a printer, a copying machine, and a recording device such as a facsimile, as well as a communication device, an office device, and a mixing device, can be used. Applicable.

1 is a schematic longitudinal cross-sectional view of a printer for performing a non-contact printing operation. As shown in the figure, the printer 1 includes a main body casing 3 having a discharge tray 5, a paper cassette 7 detachable to a lower part of the main body casing 3, and a main body casing 3; And an image forming unit 10 embedded therein. The image forming unit 10 includes a drum unit 11 including a photosensitive drum 12 disposed at the center of the main body casing 3, and an exposure unit 16 provided at an upper and lower portion of the drum unit 11, respectively. And a developing unit 21 and a cleaner unit 31 provided in front and rear of the paper transfer unit 18 and the drum unit 11, respectively.

The drum unit 11 includes a charging roller 14 adjacent to the upper portion of the photosensitive drum 12 and a transfer roller 13 adjacent to the lower portion. The paper conveying unit 18 is provided below the drum unit 11 to form a paper conveying path 19 between the paper cassette 7 and the discharge tray 5. The paper conveyed along the paper conveying path 19 passes between the photosensitive drum 12 and the transfer roller 13. The exposure unit 16 includes, for example, a laser light source or an LED light source, and these light sources emit light in accordance with image information to form an electrostatic latent image on the surface of the photosensitive drum 12.

As can be seen in more detail in FIG. 2, the developing unit 21 contains a one-component nonmagnetic toner 29, a toner receptor 22 having a toner outlet toward the photosensitive drum 12, and a toner receptor. A developing roller 23 and a supply roller 24 provided in the toner discharge port region of the toner discharge region 22 so as to be mutually rotatable, and a regulating blade which is provided at the toner discharge port and regulates the toner layer formed on the surface of the developing roller 23. (25) is provided. The apparatus further includes a toner stirring member 26 which stirs and supplies the one-component nonmagnetic toner 29 contained in the toner container 22 to the feed roller 24.

On the other hand, the cleaner unit 31 includes a scratching blade 32 for removing toner remaining on the surface of the photosensitive drum 12, and a waste toner container 33 for collecting the toner removed by the scratching blade 32. It is provided.

In the printer 1 having such a configuration and performing a non-contact developing phenomenon, the feed roller 24 and the developing roller 23 are provided with a bias supply voltage of about -700 V and about-, for example, by a conventional supply control device. A bias developing voltage of 600 V is applied respectively. Then, the voltage difference of 100 V is maintained between the supply roller 24 and the developing roller 23. Of course, the bias voltage is also supplied to the photosensitive drum 12, the charging roller 14, and the transfer roller 13, respectively, but a description thereof will be omitted. In this state, when the toner stirring member 26 is rotated, the one-component nonmagnetic toner 29 is supplied to the supply roller 24.

The supplied toner 29 is attached to the surface of the supply roller 24 and passes through the contact surface of the supply roller 24 and the developing roller 23 while rotating together. At this time, the one-component nonmagnetic toner 29 is charged by the frictional contact force between the supply roller 24 and the developing roller 23. Here, the charge amount of the toner can be expressed by the amount T corresponding to the hatched portion in Fig. 3 showing the level of the voltage applied between the supply roller 24 and the developing roller 23 which maintains a constant voltage difference. Do. The charged toner is moved from the supply roller 24 toward the developing roller 23 in an electric field maintained at a constant voltage difference, and forms a toner layer on its surface by electromagnetic force centering on the developing roller 23.

On the other hand, the toner layer formed on the surface of the developing roller 23 is managed to have a uniform thickness as a whole by the regulating blades 25 when the developing roller 23 rotates. In other words, a uniform toner layer coated with charged toners is formed on the surface of the developing roller 23. The charged toners uniformly coated in this manner again move toward the photosensitive drum 12 by the voltage difference between the developing roller 23 and the photosensitive drum 12. The toner transferred to the photosensitive drum 12 is applied to the electrostatic latent image to form a visible image, and then the visible image is transferred to the printing paper by the high pressure transfer roller 13.

By the way, in the apparatus for developing in a non-contact manner, when the toners applied to the surface of the developing roller 23 are not sufficiently charged, the amount of charged toner supplied to the photosensitive drum 12 is insufficient to sufficiently apply the electrostatic latent image. There is a problem that the background phenomenon of the image occurs accordingly. Toner that has not been sufficiently charged also has a problem that the force constrained to the electric field is weak, so that the gap between the developing roller 23 and the photosensitive drum 12 cannot be jumped and is scattered in the cabin. Therefore, in the non-contact developing method, an external additive is generally added to increase the charging efficiency of the toner.

However, the external additive is separated from the toner by stress caused by mechanical friction between the developing roller 23 and the supply roller 24 or between the developing roller 23 and the regulating blade 25. The toner having the external additive deteriorated and its charging characteristics deteriorated is fused to the surface of the developing roller 23 or the contact surface of the developing roller 23 and the regulating blade 25 as time passes gradually, There is a problem of deterioration. This problem is particularly acute after the toner in the toner receptor 22 is consumed over a certain amount, as described later.

Therefore, in recent years, various studies have been conducted to improve the above problems, and as a result of this, if the voltage difference between the developing roller 23 and the supply roller 24 is properly adjusted, the charging efficiency of the toner is improved. And supplyability can be varied. 4 is a graph comparing the degree of background generation according to the increase in the printing amount when the voltage difference between the supply roller and the developing roller is changed. Here, it is understood that as the print amount increases, the toner contained in the toner container 22 is used up.

In the figure, the horizontal axis represents the amount of printing, that is, the number of printed sheets, and the vertical axis represents the background density. And, the graph A shows the change in background density as the printing amount gradually increases while the voltage difference ΔV between the developing roller 23 and the supply roller 25 is maintained at 200 V, and the graph B shows the voltage difference. It shows the change of background density in the state kept at 100V.

Referring to the drawing, when the voltage difference is kept constant at 100V, as shown in the graph A, the change in the background concentration is not severe, and it can be seen that the background concentration is lower than when maintaining the voltage difference at 200V. . However, when the printing amount, that is, the number of printing papers is 6,000 or more, the supply of toner gradually increases, and the background phenomenon is more severe when the voltage difference is maintained at 100V than at 200V. .

Therefore, in summation of these comparison results, even if the printing amount, i.e., the number of printing paper gradually increases, if the voltage difference between the supply roller 24 and the developing roller 23 is appropriately varied, the one-component nonmagnetic toner 29 It can be suggested that the charging efficiency and the supplyability can be prevented from being lowered. In other words, even if the developing unit 21 has reached the end of its life as time passes, that is, even if the amount of toner gradually decreases, the background voltage is properly varied by varying the voltage difference between the developing roller 23 and the supply roller 24. The problem of development and toner scattering can be solved.

Accordingly, it is an object of the present invention, in view of the above-mentioned conventional problems and research results, to vary the voltage difference between the supply roller and the developing roller in accordance with the amount of printing performed by the non-contact developing apparatus, whereby the toner in the toner container is exhausted. The present invention provides a voltage control device and a voltage control method capable of maintaining the charging efficiency and supplyability of toner almost uniformly.

Another object of the present invention is to provide a voltage control apparatus for a non-contact developing apparatus, which can maintain a uniform image quality regardless of the use time or the amount of toner contained in a toner container, thereby improving the reliability of the product to the consumer. It is to provide a voltage control method.

1 is a schematic longitudinal sectional view of a general non-contact developing device;

FIG. 2 is an enlarged view of the main part of FIG. 1, and more specifically illustrates a coupling state between a supply roller, a development roller, and a toner receptor;

3 is a view showing waveforms of a supply voltage level applied when a constant voltage difference is maintained between a supply roller and a developing roller according to a voltage control device of the conventional non-contact developing device and the voltage control method thereof;

4 is a graph comparing the degree of background occurrence according to the increase in the printing amount when the voltage difference between the supply roller and the developing roller is different;

5 is a schematic block diagram of an apparatus for controlling a supply voltage of a non-contact developing device according to the present invention;

6 is a flowchart illustrating a method for controlling a supply voltage of a non-contact developing device according to the present invention;

7 is a supply voltage level applied when the level of the AC voltage component is controlled so that the voltage difference between the supply roller and the developing roller is equal to or greater than the standard voltage difference when the total print amount exceeds the reference print amount. A diagram showing the waveform of, and

8 is a waveform of a supply voltage level applied when the level of the DC voltage component is controlled so that the voltage difference between the supply roller and the developing roller is equal to or greater than the standard voltage difference when the total print amount is equal to or greater than the reference print amount. It is a diagram showing.

<Description of main parts of drawing>

3: main body casing 10: image forming unit

11: drum unit 12: photosensitive drum

21: developing unit 22: toner receptor

23: developing roller 24: feeding roller

25: regulation blade 26: toner stirring member

50: voltage control device 52: micom

53: print amount measuring unit 55: voltage control unit

According to the present invention, there is provided a method, comprising: applying a supply voltage to a supply roller capable of supplying a one-component nonmagnetic toner contained in a toner container to a developing roller; And charging and supplying the one-component nonmagnetic toner by applying a developing voltage having a predetermined standard voltage difference to the developing roller to charge the one-component nonmagnetic toner. Measuring the total amount of printing performed by the non-contact developing apparatus with respect to the total amount of the one-component nonmagnetic toner contained in the container; Maintaining the voltage difference between the supply voltage and the developing voltage smaller than the standard voltage difference when the measured total print amount is less than or equal to the reference print amount; And when the measured printing amount reaches the reference printing amount, adjusting the voltage difference to be larger than the standard voltage difference.

The measuring of the total amount of printing may include preparing data on an average number of dots that can be printed on one sheet of printing paper; Counting the total number of dots performed by the non-contact developing apparatus equipped with the unit toner receiver; And counting the number of sheets of paper that can be printed by the total number of dots, and applying the total printing amount, or printing that can be printed by the total amount of the one-component nonmagnetic toner contained in the unit toner container. Providing data regarding the number of sheets; Calculating the amount of used toner by detecting the remaining amount of the one-component nonmagnetic toner in the unit toner container; And calculating the number of sheets printed by the used toner amount, and applying the total amount of printed paper.

At this time, it is preferable that the reference print amount is based on a predetermined number of sheets printed by the non-contact developing apparatus equipped with the unit toner receptor.

The adjusting of the voltage difference to be greater than the standard voltage difference may be performed by adjusting the level of the AC voltage component of the supply voltage or by adjusting the level of the DC voltage component of the supply voltage.

The above object is, on the other hand, in the voltage control apparatus of a non-contact developing apparatus having a supply roller for supplying a one-component nonmagnetic toner contained in a toner receptor to a developing roller having a predetermined standard voltage difference, wherein the unit toner receptor is mounted; A microcomputer for storing data relating to a voltage difference adjustment value between the feed roller and the developing roller associated with an increase in printing amount performed by the non-contact field apparatus; A print amount measuring unit for measuring the total amount of printing performed by the non-contact developing apparatus equipped with the unit toner receptor; And based on a measurement signal from the print quantity measuring unit, maintains a voltage difference between the supply voltage and the developing voltage smaller than the standard voltage difference when the total print amount is less than or equal to the reference print amount, and sets the standard voltage difference when the total print amount is less than the reference print amount. It is also achievable by a voltage control device of a non-contact developing device including a voltage adjusting means for adjusting to be larger.

Wherein the print amount measuring unit measures the print amount based on a signal from an optical sensor for detecting the remaining amount of the one-component nonmagnetic toner remaining in the unit toner receptor; It is simply configurable to measure the print amount based on the total number of dots printed by the one-component nonmagnetic toner contained in the unit toner receptor.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention. Here, the same reference numerals are assigned to the same configurations and the same names related to the above-described and illustrated FIGS. 1 and 2, and the description of the components of the same reference numerals will be omitted.

5 is a schematic block diagram of an apparatus for controlling a supply voltage of a non-contact developing device according to the present invention. As can be seen from this figure, the voltage control device 50 supplies a commercial voltage in accordance with the control signals of the microcomputer 52 and the microcomputer 52 to which commercial power from the power supply unit 51 is applied. 24 and a voltage converting unit 54 for converting the supply voltage and the developing voltage of the developing roller 23, a voltage adjusting unit 55 for adjusting the supply voltage and the developing voltage, respectively, and a print quantity measuring unit for measuring a print workload ( 53).

In the microcomputer 52, data relating to the voltage difference between the supply roller 24 and the developing roller 23 with respect to the print amount is stored. This data is the number of print papers that can be performed with the total amount of the one-component non-magnetic toner 29 contained in the unit toner container 22, that is, the residual toner present in the unit toner container 22 when 6,000 sheets of paper are printed. Information such as the quantity and average number of dots printed on one sheet of paper. Here, the unit toner receptor 22 means a new toner receptor filled with the one-component nonmagnetic toner 29.

The print quantity measuring unit 53 can be simply configured as a developing device, for example, a calculator for counting the total number of dots performed by the printer 1, or an optical sensor for detecting the amount of toner remaining in the toner container 22. .

On the other hand, specifications and development conditions, and physical properties of the other components of the present invention are as follows.

[Specifications and Developing Conditions of Regulating Blade 25]

1.Material: SUS (Steel special Use Stainless)

2. Contact the developing roller at a pressure of 10 to 50 g / cm

[Specifications and Developing Conditions of Developing Roller]

1.Material: NBR (Nitrile Rubber or BuNA-N) rubber of elastic material

2. Surface Roughness: 3 to 9㎛

3. Resistance: 1 × 10 ⁵ to 5 × 10 ⁶ Ω

4. Gap with the photosensitive drum: 150 to 400 ㎛

5. Applied voltage (V _pp ): 1.8㎸

6. Frequency: 2.0㎑

7. Applied DC voltage (V _dc ): -500V

[Mask and Developing Condition of Feed Roller]

1.Material: Urethane Foam

2. Maintain constant NIP with developing roll

3. Applied voltage: Synchronous with developing bias voltage

4. Applied DC voltage (V _dc ): -700V

5. Applicable AC voltage (V _ac ): Synchronous with developing bias voltage

[Property of Toner]

1. One-component nonmagnetic toner: thermoplastic + colorant

2. Addition of external additives

[Etc]

Voltage difference between developer and supply roller: 200V (hereinafter referred to as standard voltage difference)

Hereinafter, a method of controlling the supply voltage using the voltage control device of the non-contact developing apparatus having such a configuration will be described with reference to the drawings showing waveforms of the supply voltage levels of FIGS. 7 and 8.

6 is a flowchart illustrating a method of controlling a supply voltage of a non-contact developing device according to the present invention. When the print command is applied (S1), the microcomputer 52 first measures the total amount of work performed after the unit toner receptor 22 is mounted on the basis of the signal applied from the print quantity measuring unit 53 (S2). Here, the total amount of work can be measured simply by detecting the remaining amount of toner left in the toner container 22 using an optical sensor, and then calculating the number of printable papers by the amount of used toner. The total workload may, on the other hand, be measured by counting the total number of dots printed using a calculator, and then calculating the number of printable sheets as the total number of dots.

As such, when the total amount of work, that is, the number of printed sheets is measured (S2), the measured amount is compared with the reference print amount (S3). Here, it is preferable that the reference print amount is based on 6,000 printing paper indexes in connection with the conventional description of FIGS. 1 to 3. Thus, when the total workload is less than or equal to the reference print quantity, that is, when the number of sheets printed using the unit toner receptor 22 is less than 6,000 sheets, the voltage difference between the feed roller 24 and the developing roller 23 is determined by the standard voltage. It keeps below difference 200V (S4).

In this embodiment, for example, the bias voltage of the developing roller 23 is applied at -700V, and the bias voltage of the supply roller 24 is applied at -600V, so that the voltage difference between the rollers 23, 24 is reduced. It can be maintained at 100V below the standard voltage difference. Then, the level of the supply voltage can be represented by a waveform similar to that described with reference to FIG. 3, wherein the charge amount of the toner can be expressed by the amount T corresponding to the hatched portion as described above. .

However, when the total amount of work, ie, the number of printed sheets, becomes more than 6,000 print sheets, the standard print quantity, the voltage difference between the supply roller 24 and the developing roller 23 is adjusted to be equal to or more than the standard voltage difference (S5). In this embodiment, the voltage difference equal to or greater than the standard voltage difference is kept at 200V.

Here, the voltage difference is simply adjustable by varying the voltage applied to the supply roller 24 with respect to the developing voltage of the developing roller 23. The voltage difference adjustment method can be selected from one of a method of lowering the level of the AC voltage component applied to the supply roller 24 and a method of lowering the level of the DC voltage component.

On the other hand, Figure 7 is a supply when applied when the level of the AC voltage component is lowered so that the voltage difference between the supply roller and the development roller is more than the standard voltage difference in accordance with one embodiment of the present invention, when the total print amount reaches the reference print amount A diagram showing waveforms of voltage levels. Referring to the drawings, when the level of the AC voltage component is lowered, the width of the supply bias voltage is increased with respect to the developing bias voltage, so that the actual charge amount of the toner can be expressed by the area T1 corresponding to the hatched portion.

Here, T1 has a relatively large area compared with T of FIG. 3. Therefore, the difference between these areas, that is, the value corresponding to T1-T, can be applied to the amount of charge and supply increase that can be obtained by lowering the level of the AC voltage component to 6,000 sheets or more of printing paper. That is, by adjusting the level of the AC voltage component, the charging efficiency and supplyability by the value corresponding to T1-T can be improved, which in turn increases the reliability of the quality of the printed image.

8 is a supply voltage level applied when the DC voltage component is lowered so that the voltage difference between the supply roller and the developing roller is equal to or greater than the standard voltage difference when the total printing amount reaches the reference printing amount, according to another embodiment of the present invention. Is a diagram showing waveforms. Referring to the drawings, it can be seen that the supply bias voltage is lowered with respect to the development bias voltage by lowering the level of the DC voltage component, and in this embodiment as well, the area T2 of the hatched portion that can be expressed by the actual charge amount of the toner is also shown. It can be seen that this is increased. Therefore, even in the printing operation of 6,000 sheets or more, the charging efficiency and supplyability of the same one-component nonmagnetic toner 29 can be maintained uniformly before that.

On the other hand, based on the total printing amount, after performing the printing in a state in which the voltage difference between the supply roller 24 and the developing roller 23 is kept below or above the standard voltage difference, it is checked whether or not continuous printing (S6). . At this time, in the case of performing continuous printing, voltage control between the supply roller 24 and the developing roller 24 in the above-described order is repeatedly performed. If continuous printing is not performed, printing is terminated (S7).

On the other hand, in the above-described and illustrated embodiments, it has been described that a series of steps for controlling the supply voltage is repeatedly performed depending on whether or not continuous printing, but when the workload, that is, the number of printed sheets becomes 6,000 or more, It will be preferable to keep the voltage difference between the supply roller 24 and the developing roller 23 above the standard voltage difference in the printing operation after that until the toner container 22 is replaced.

In the above-described and illustrated embodiments, on the other hand, for ease of explanation and understanding, the standard voltage difference is limited to 200V, the voltage difference over the standard voltage difference is described by applying 200V, and the voltage difference below 100V. Of course, the voltage difference values can be applied as appropriate experimental results depending on the performance and the working capacity of the device.

As described above, according to the present invention, according to the amount of printing performed by the non-contact developing apparatus, the voltage difference between the feed roller and the developing roller is varied based on, for example, 6,000 sheets of printing paper, and the toner in the toner container is exhausted. A voltage control device and a voltage control method thereof are provided which can maintain the charging efficiency and supplyability of a toner almost uniformly until it is obtained.

The voltage control device of the non-contact developing device and the voltage control method thereof can also maintain the image quality uniformly regardless of the usage time or the amount of toner contained in the toner container, thereby improving the reliability of the product to the consumer. Excellent effect is provided.

Claims (9)

Applying a supply voltage to a supply roller capable of supplying the one-component nonmagnetic toner contained in the toner container to the developing roller; And charging and supplying the one-component nonmagnetic toner by applying a developing voltage having a predetermined standard voltage difference with the supply voltage to the developing roller. Measuring the total amount of printing performed by the non-contact developing apparatus with respect to the total amount of the one-component nonmagnetic toner contained in a unit toner container; Maintaining the voltage difference between the supply voltage and the developing voltage less than the standard voltage difference when the measured total print amount is less than or equal to the reference print amount; And And adjusting the voltage difference to be greater than the standard voltage difference when the measured printing amount reaches the reference printing amount. The method of claim 1, wherein the measuring of the total printing amount comprises: Providing data regarding an average number of dots that can be printed on one sheet of printing paper; Counting the total number of dots performed by the non-contact developing apparatus equipped with the unit toner receiver; And And calculating the number of sheets of paper that can be printed by the total number of dots, and applying the total amount of printed paper. The method of claim 1, wherein the measuring of the total printing amount comprises: Providing data relating to the number of print sheets that can be printed by the total amount of the one-component nonmagnetic toner contained in the unit toner container; Calculating the amount of toner used by detecting the remaining amount of the one-component non-magnetic toner in the unit toner container; And And calculating the number of sheets printed by the used toner amount and applying the total amount of printed paper. The method of claim 2 or 3, The reference printing amount is a voltage control method for a non-contact developing device, characterized in that the reference number of sheets printed by the non-contact developing device equipped with the unit toner receptor. The method of claim 1, And adjusting the voltage difference so as to be larger than the standard voltage difference, and controlling the level of the AC voltage component of the supply voltage. The method of claim 1, And adjusting the voltage difference so that the voltage difference is greater than the reference voltage difference, and adjusting the level of the DC voltage component of the supply voltage. A voltage control apparatus for a non-contact developing apparatus comprising: a supply roller for supplying a one-component nonmagnetic toner contained in a toner container to a developing roller having a predetermined standard voltage difference; A microcomputer for storing data relating to a voltage difference adjustment value between the feed roller and the developing roller associated with an increase in printing amount performed by the non-contact field apparatus equipped with a unit toner container; A print amount measuring unit for measuring the total amount of printing performed by the non-contact developing apparatus equipped with the unit toner receptor; And On the basis of the measurement signal from the print quantity measuring unit, the voltage difference between the supply voltage and the developing voltage is kept smaller than the standard voltage difference when the total print amount is less than or equal to the reference print amount, and when the total print amount is less than the standard print amount, Voltage control device of a non-contact developing device comprising a voltage adjusting means for adjusting to a large. The method of claim 7, wherein the print amount measuring unit, And the printing amount is measured on the basis of a signal from an optical sensor for detecting the remaining amount of the one-component nonmagnetic toner remaining in the unit toner receptor. The method of claim 7, wherein the print amount measuring unit, And the printing amount is measured on the basis of the total number of dots printed by the one-component nonmagnetic toner contained in the unit toner container.