DE2410741A1 - CONTROLLER FOR REPRODUCTION EQUIPMENT - Google Patents

Description

Xerox Corporation, Rochester, N.Y. / USA 9Λ1Π7Α1

Reproduction device controller 24 965

The invention relates to an improved reproduction device having an electrostatic controlled by an electrometer Development field and in particular a reproduction device with an electrometer, in which the energy supply for the electrometer and for the development field device part controlled by the electrometer one and the same.

The invention relates to a device for regulating the electrostatic development field in a reproduction device to assist the development of the electrostatic latent image on the photoconductive part of the reproduction machine, said reproduction machine being associated with the electrostatic Device parts contributing to the development field a charging device for

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Loading the photoconductive part in preparation for the composition, an exposure device for exposing the charged photoconductive Partly to obtain an electrostatic latent image of the original on the photoconductive member, and a developing device for developing the image.

It is known to those skilled in the copier art that the effectiveness of electrostatic copiers depends on the correct relative charge which is maintained between the photoconductive member and the developing device will. Because of this charge ratio or electrostatic development field, developer material, i. Toner, from a supply source to the photoconductive part, according to both the outline and the density of the electrostatic Image attracted to the photoconductive part. The electrostatic image that is subject to this development can be formed in that the previously charged photoconductive member is a light image of the original to be copied is exposed.

A method of promoting proper charge relationships between the photoconductive member and the developing device is to use a potential sensor, commonly called an electrometer, to measure the potentials on the photoconductive Capture part at an appropriate point. This device can be used as a maintenance tool, with the help of a Measuring device a visible display of the charge level of the FotQ receptor after which the electrostatic development field can be adjusted by hand. In other cases a feedback loop can be provided to provide an automatic To enable regulation of the development field via the electrometer. The regulation of the electrostatic development field can, for. B. by controlling or regulating the developer bias or by controlling the potentials on the photoconductive

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Part itself by regulating the corona charger or exposure device of the copier.

The copier or reproduction device contains energy sources in order to provide the individual parts of the device with the necessary electrical energy To supply energy. The machine parts of the copier include those parts which are responsible for the development of the latent electrostatic Images on the photoconductive part are responsible. The power supplies of the copier are, however normally housed enclosed in the copier, making maintenance and repair difficult. Can continue from economic reasons a power supply of the copier different parts of the device are used, so that the failure in a part of the energy supply a difficult and expensive replacement or repair of the entire energy supply may be required for the copier.

The aim of the invention is based on the possibilities mentioned and apparatus an improved reproduction apparatus having a device for regulating the electrostatic development field to accomplish.

This goal is achieved with a device of the type described in the opening paragraph, which according to the invention comprises the combination a potential regulator with a probe arranged adjacent to the photoconductive part for detecting the potentials on the photoconductive part Part and a regulator section for regulating an energy source in such a way that a regulated voltage in response from the energy source on changes in potential detected by the probe on the photoconductive part is output, the controller a having internal energy source for its control, a device for coupling the energy source of the controller with at least one of the device parts contributing to the electrostatic development field, whereby the own energy source of the

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Regulator serves as an energy source for the device part, and a
Circuit for coupling the controller section of the controller with
the energy source of the regulator to a regulated voltage
for one part of the device with the following regulation of the
to obtain electrostatic development field.

Appropriate embodiments and developments of the invention emerge from the claims.

The invention provides a copier in which the bias voltage source for the developer of the copier is the regulating
Electrometer includes. An automatic potential regulator for copiers is created, in which the energy supplies for the regulator and for the regulated part of the copier
are designed as a single power supply. In particular, the controller used with the copier can serve both as an electrometer and as a bias source for the copier's development system.

The invention provides a reproduction device with an electrometer regulator created with which the electrostatic development field of the device is automatic in response to changes in the operating potential of the photoreceptor of the reproduction device can be regulated, the regulated development field device part contains the power supply of the electrometer.

In particular, the invention provides an improved electrometer controller for regulating the bias voltage on the magnetic brush developing device of a reproduction machine which the controller both as a bias source for the Ent winding device as well as serving as a regulating element for this.

Further details and advantages of the invention will emerge from the following description in conjunction with the drawing.

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Show in the drawing

Fig. 1 is a schematic sectional view of an electrostatic reproduction machine having an automatic one Potential regulator according to the invention,

Fig. 2 is a side view of the magnetic brush developing device for the reproduction device shown in Fig. 1,

Fig. 3 is a side view from the opposite side of the magnetic brush developing device shown in Fig. 2; which shows the drive mechanism for the magnetic brush roller device,

4 is a top plan view of the magnetic brush assembly showing details of the mechanism for applying a Shows the bias on the magnetic brushes,

5 shows a schematic view of the automatic potential regulator according to the invention in combination with the reproduction device of Fig. 1, and

Figure 6 is a schematic diagram of the interconnecting circuit of the automatic potential regulator shown in FIG.

For a general understanding of the copier or reproduction machine shown, with which the invention can be used is shown in Fig. 1 an example of a reproducing or copying machine 5 shown, which is an automatic potential regulator or controller 100 according to the invention.

An original 11 to be copied is placed on a transparent carrier

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Plate 16 brought, which is firmly attached to a lighting arrangement 10 on the left side of the device 5. Light beams from a lighting system are guided to the original in a flash to form image beams corresponding to the information areas to create. The image rays are applied to the photosensitive surface with the aid of an optical system a xerographic plate in the form of a flexible photoconductive belt 12 which rests on a belt assembly 14 is appropriate, projected.

The belt 12 includes a photoconductive layer on a conductive backing Layer of selenium, which is the surface that absorbs the light and the medium of the device that builds up the image. The surface of the photoconductive belt is through a preliminary step of uniform charging with the aid of a corona generating device or a corotron 13 made photosensitive.

The belt is continuously movably guided over three rollers 20, 21 and 22, the axes of which are parallel to one another. The photoconductive Belt assembly 14 is slidably mounted on two supporting axles 23 and 24, the roller 22 being rotatable on that of the frame of the device mounted axis 23 is seated and by a suitable motor and a drive device, not shown, in the direction of the arrow is driven at constant speed. During the exposure of the belt 12 is of one on the Support plate arranged template, reflected light image in flashes or intermittently brought onto the surface of the belt, around in an exposure station 27 a latent electrostatic To generate image on the tape.

As the surface of the belt continues to move, the electrostatic image passes through a development station 28, in which a developing device 30 with a magnetic brush

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is arranged. In the development station, the electrostatic Image developed with the help of several brushes as it moves through the development zone, as shown below is described in more detail.

The developed electrostatic image becomes one from the hand Transfer station 29 brought where a sheet of copy paper or a transmission part at a speed synchronous to move the moving belt between a transfer roller and the belt to effect a transfer of the developed image solely with the help of an electrical pre-tension on the transfer roller transferred to. In this station, a transport mechanism 17 is provided for sheets, which paper sheets from a paper handling mechanism 18 to move the developed image on the belt in transfer station 29.

After the sheet is stripped from the belt 12, it is transferred to a fuser assembly 19 where the developed and transferred xerographic powder image on the sheet material is permanently fixed on this. After melting, the finished copy will be dispensed from the device at a suitable point for collection outside the device. The rest on the developed image Residual toner particles, background particles, and those particles that have not otherwise been transferred are removed from the belt 12 brought to a cleaning device 26, which in the edge zone of the tape is arranged between the rollers 20 and 22 adjacent to a loading device 25. More details regarding the structure of the belt arrangement 14 and its connection with the device and the supporting structure for this can be found in the parallel Applicant's U.S. patent application serial number 102,312.

Referring to Figs. 2 to 4, there is a magnetic brush developing device 30 shown, which has a series of rollers 36, the

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are mounted in end plates 32, 34 of a frame. The rollers 36 consist of a cylindrical sleeve 46 with a roughened Surface made of non-magnetizable material and extend extending almost the entire length of the housing of the developing device 30. End sleeves 48 are made of an insulating material shrunk onto the cylindrical sleeve 46 at the ends thereof. One end of the sleeve 46 is closed with a cap 50 which has a Roller drive shaft 52 coaxial with sleeve 46 carries. The other end of the sleeve 46 has a cap 54 with an opening 56 closed, through which the axis 58 of the inner bar magnets 61 protrudes. Appropriate bearings 60 are provided for rotation of the sleeve 46 relative to the axis 58 to enable.

The roller drive shafts 52 are supported in bearings in the end plate 32 and carry drive wheels 96 at their protruding ends. The drive wheels 96 are made of an insulating material.

As can be seen in particular from FIGS. 2 and 3, the magnetic roller arrangement is or developing device 30 disposed in a housing 66 which is substantially rectangular in cross-section and has a length which exceeds the width of the photoconductive belt 12. The housing 66 is essentially closed except for an opening opposite the photoconductive one Belt 12 where the latent image development on belt 12 is effected. The housing 66 also serves as a container for development material. The developing material consists of carrier granules made of magnetizable material and colored electrostatic Toner particles adhering to the former.

To provide a bias for the magnetic brush rollers or rollers 36 To provide a suitable wiper 50 is provided in electrical contact with the axes 58 of the bar magnets 61, which extends along and is carried by side plate 34 for electrical connection from a power supply

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supply section 113 of the automatic potential regulator or Regulator 100 to each of the sleeves 46 of the rollers. A line 71 connects the wiper 70 to the regulator 100. During During development, the rollers 36 are rotated in the same direction by a suitable drive via the drive wheels 96 the inner bar magnets 61 remain stationary. The by the influence of the bar magnets 61 and the magnetizable Carrier granules in the developer material acting electric field generated brush bristles will be on the Form the upper region of the sleeves 46 adjacent to the underside of the belt 12 with selenium.

This results in the shape of a "magnetic blanket", which continuously from one roller brush 36 to the other across the entire width of the development zone or development station 28 runs where material is deposited or, to a certain extent, is available for development purposes. more details the structure and operation of the "magnetic blanket" are described in co-pending US patent application Ser. No. 330,285 Applicant described.

The controller 100 according to FIGS. 1, 5 and 6 contains an electrometer 116 with a suitable probe 101 for detecting potentials on the photoconductive belt 12. In the arrangement shown as an example, the probe 101 is adjacent to the belt 12 and in operative connection therewith mounted at a point between the corotron 13 and the exposure station 27. The probe 101, which is conveniently located in the center of the belt 12, detects the potential on the photoconductive surface of the belt 12 after the belt has been charged, but before exposure, since the exposure leads to a selective discharge of the belt 12. Is located between the electrometer 16 and the copier, or the device 5, as explained in more detail below, a circuit _t 119th

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The electrometer 116 is designed so that it a the potentials output signal reproducing the tape. The electrometer

116 has an internal power supply section 113 for operating the electrometer parts. The power supply section 113 of the electrometer usually contains a suitable rectifier for converting an alternating current in the input to one Line L1, L2 into a direct current. The power supply section 113 can be converted into a low-voltage section 114 and into a high voltage section 115 may be divided.

6, circuit 119 includes a suitable one Function amplifier 120 for converting a relatively high signal

117 from the electrometer 116 to one for a summing circuit 122 suitable height. The output of the summing circuit 122 is connected to an integrating circuit 121, which has a function amplifier 123 and a capacitor 124 as a feedback or Having signal storage capacitor. The summing circuit 122 sums the electrometer signal from the functional amplifier 120 to a predetermined reference potential from a functional amplifier 126, which in turn is determined by the setting of a switch 130 for bias control. the The voltage source for the reference potential is the low-voltage section 114 of the power supply. The resulting low voltage signal output the integrating circuit 121 is fed to a high-voltage circuit 128.

A voltage tap 115 ′ is on the high-voltage section 115 of the power supply section 113 for the electrometer is provided. The high-voltage circuit 128, which contains a function amplifier 129, is used to control the voltage from the high-voltage section 115 to the magnetic brush rollers 36 of the development station 28 in response to the control signal from the integrating circuit 121 applied bias. The controlled output of the high voltage circuit 128 is via line 71 to the

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Wiper 70 led to the required operating bias for the sleeves 46 of the magnetic brush rollers.

The bias control switch 130 allows for presetting the amount of bias on the rollers 36. The switch 130 is used to increase the resistance in the bias circuit to the puncture amplifier 12'6 and thus this to change the supplied reference potential.

The low voltage section 114 of the power supply section 113 is used to obtain the mentioned bias voltage for the functional amplifier 126. This is why there are resistors 132, 133, 134 are provided, which by the switch 130 optionally in the bias circuit of the functional amplifier be switched on.

It will be understood by those skilled in the art that the development of the electrostatic latent image built up on the belt 12 can occur from the voltage differential between the latent image and the developing device depends. This voltage differential, which can be described as the xerographic development field serves to attract toner to the electrostatic latent image according to the outline and density of the image faithfully reproduce the copied original. The strength and the structure of the xerographic field of development can e.g. can be set so that the charging voltage for the image areas and the areas without an image is raised or lowered, which is achieved by Changing the energy supply to the corotron 13 can be done. Alternately For example, the bias voltage applied to the magnetic brush rollers 36 can be changed, or in the case of an electrode development system the voltage applied to the developing electrode or electrodes can be changed.

As described above, controller 100 serves as both a source

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as well as to control the bias for the magnetic brushes of the rollers 36 in response to the tension conditions on the belt 12, thus regulating the xerographic development field as described above. Alternatively, a regulation or control can be accomplished through the corotron 13, and in this case the high voltage portion 115 is the controller 100, the output of which can be suitably modified, _y to give the required voltage levels for the corotron 13, and which in response to the loading conditions on the belt 12 is controlled by the controller 100, as an energy source for the loading device or the corotron 13.

While the invention has been described in connection with a preferred embodiment, it is not based on The details presented here are limited to, but include all modifications and changes within the scope of the conception of the Invention and in particular the claims.

Briefly stated, the invention comprises a copier or reproducing machine with a photoconductive plate, a corona generating device for loading the plate in preparation for image formation on this, an exposure device for exposing the loaded plate with a light image of the copied original, a Developing means for supplying developing material to the electrostatic image, and a transfer means for transferring the developed image to a supporting material, i.e., a copy sheet.

In order to control the electrostatic development field to reach between the photoconductive plate and the developing section, and thereby the development unterstützen.ist an automatic potential regulator containing an electrometer _/ provided.

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The electrometer has a probe section which is arranged to detect voltages on the plate, wherein The purpose of the electrometer is to produce a signal corresponding to the plate potentials. The signal from the electrometer is used by the controller to control the electrostatic development field, for example by regulating the amount supplied to the developer Adjust preload automatically. The electrometer has its own internal power supply for the electrometer components, and circuits are provided to respond to the internal energy supply, regulated by the controller itself to changes in the electrostatic development field, to use as a bias source for the developer and thereby avoid the need for separate and additional energy supplies.

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Claims (7)

Claims Device for regulating the electrostatic development field in a reproduction device for assistance the development of the electrostatic latent image on the photoconductive part of the reproduction machine, the reproduction machine as device parts contributing to the electrostatic development field, a charger for charging the photoconductive part in preparation for the composition, a Exposure means for exposing the charged photoconductive member to form an electrostatic latent image of the original to achieve on the photoconductive member, and a developing device for developing the image, g e k en η draws by combining a potential regulator (100) with one arranged adjacent to the photoconductive part (12) Probe (101) for detecting the potentials on the photoconductive part (12) and a regulator section for regulating an energy source (113) such that from the energy source (113) a regulated Voltage is output in response to changes in potential detected by the probe (101) on the photoconductive member (12) wherein the controller (100) has an internal energy source (113) for its control, means (119) for coupling the energy source (113) of the controller (100) with at least one of the device parts contributing to the electrostatic development field, whereby the own energy source (113) of the controller (100) serves as an energy source for the device part, and a circuit for coupling the regulator section of the regulator (100) to the energy source (113) of the regulator to provide a regulated voltage for the device part with consequent regulation of the electrostatic Development field. 2. Apparatus according to claim 1, characterized in that the developing device (30) of the reproduction device contains at least one magnetic brush and the A09850 / 1021 - 15 - Energy source (113) of the controller (100) is operatively coupled to the magnetic brush to the magnetic brush accordingly to bias the changes in potential on the photoconductive part (12) as indicated by the probe (101) of the controller (100) can be detected. 3. Apparatus according to claim 1, characterized in that the loading device of the reproduction device a corona generator (13) for charging the photoconductive member (12) in preparation for image formation, and the Energy source (113) of the controller (100) with the corona generator (13) is coupled to the photoconductive member (12) accordingly to load the changes in potential on the photoconductive member (12) as detected by the probe (101) of the controller (100) will. 4. Apparatus according to claim 1, characterized by means (130) for selecting the potential control point of the controller (100) and means (121, 122) for obtaining a control signal in accordance with the context between the selected potential control point and the potential detected by the probe (101) of the controller (100), the control section of the regulator (100) regulates the output voltage of the energy source (113) in response to the control signal. 5. Copier with a photoconductive part on which images are electrostatically transferred to copy sheets be developed, with a control device according to one of claims 1 to 5 and with a charging device for charging the photoconductive part in preparation for image formation, an exposure device for discharging selective parts of the photoconductive member in accordance with the copied image, one A device comprising a biasable part for developing the image, a device for transferring the developed image 409850/1 021 - ₁₆ _ on the photoconductive part to a copy sheet and an electrometer for controlling the bias on the developing device member in response to charge potentials on the photoconductive one Part of helping the development of the electrostatic image, where the electrometer has a probe to monitor the Has voltage potentials on the photoconductive part and an internal energy supply for the operation of the electrometer, gekennz eichnet that the power supply (113) of the electrometer (116) with the developing device part (36) is connected to the developing device part (36) according to the voltage potentials on the photoconductive part (12) to apply a regulated bias voltage, thereby providing a power supply (113) as well as operating the electrometer (116) Energy source as well as a bias source for the developing device part (36) works. 6. Copier according to claim 5, characterized in that g e k e η η ζ It is assumed that the developing device member (36) is a magnetic brush. 7. Device for controlling the electrostatic development field a reproduction device in response to the charge states of the photoconductive surface of the reproduction device, in particular according to one of claims 1 to 4, with a internal energy source for operating the device, characterized by a circuit (119) for Coupling the power source (113) to the reproduction device to provide an electrical bias to support the development field and regulating means (100) for regulating the output voltage of the energy source (113) in response to the states of charge the photoconductive surface (12), creating the electrostatic development field in response to the charge states the photoconductive surface (12) is changeable. 409850/1021 ι * ■ Le e rs e ι te