EP1179754A2 - Process isolation program for an electrophotographic marking apparatus - Google Patents

Abstract

An electrophotographic marking apparatus has an associated marking motor control, which is characterized in that it is set to enable process isolation in the electrophotographic process. The process isolation enables the electrophotographic process to be terminated at one point, the termination being controlled by the marker motor controller. Controlled exiting is done to anticipate the effects of an emergency stop or hard stop. <IMAGE>

Description

The present invention relates to the maintenance and operational diagnosis of a electrophotographic marking apparatus, especially the optional interrupting an electrophotographic marking process during normal printing and then resuming normal printing.

Electrophotographic markers such as copiers and printers are required various forms of maintenance, such as Refill the toner and paper to make the keep the desired copy functions ready. In addition, since this Devices become more complex, the performance of the user interface is expanded when the troubleshooting in the apparatus is complete and should be designed effectively.

Diagnostic procedures often require service personnel to analyze the problem. Problems with paper transport in one machine can occur in different places and due to different conditions or malfunctions of different parts in the Apparatus occur. A difficulty with previous diagnostic services is that an easy and automatic precise identification of parts or subordinate Systems that cause equipment malfunction are not possible.

There is therefore a need for an electrophotographic marking machine which can be optionally controlled to analyze and examine the steps of the process To provide imaging prior to the completion of the electrophotographic process. Further there is a need to interrupt the electrophotographic process predetermined steps, wherein a reconfiguration process is provided to the Set the machine back to normal printing.

The present invention relates to an electrophotographic process control that different steps of imaging and handling paper from each other controls in isolation. This can be the reason for defects in the image that occur during image generation arise (e.g. lubrication, insufficient coverage, cloudy pressure), and problems in Handling the paper in the transport system (e.g. kinked corners, damage to the Edges) can be correctly identified and fixed efficiently. The present invention also enables isolation of the steps on the paper path from insertion to Finishing.

In a first construction, the invention comprises an electrophotographic Marking apparatus with a logic and control unit, which is configured to the Printing operation stops at a predetermined point before the printing operation ends, without causing a hard stop or emergency stop configuration. The predetermined point can be any copy of multiple copies, a point in time or a location correspond to the paper path. The logic and control unit is selected to one To provide regeneration sequence that returns the marker to normal Print mode.

Fig. 1

ist eine schematische Seitenansicht eines üblichen/typischen elektrophotographischen Markierungsapparats, auf den die vorliegende Erfindung anwendbar ist.

Fig. 2

ist ein Blockdiagramm einer Logik- und Steuereinheit von Fig. 1.

Fig. 3

ist ein Flussdiagramm/Ablaufdiagramm des Prozessisolierungsprogramms von Fig. 2.

The present invention further relates to a method of operating an electrophotographic marking apparatus by selectively stopping a normal operating configuration of the electrophotographic marking apparatus while the apparatus is in a printing operation at a predetermined point before the electrophotographic process is finished, and then reconfiguring / re-setting the marking apparatus on the normal printing.

Fig. 1

Figure 3 is a schematic side view of a conventional electrophotographic marking apparatus to which the present invention is applicable.

Fig. 2

FIG. 1 is a block diagram of a logic and control unit of FIG. 1.

Fig. 3

FIG. 2 is a flowchart / flowchart of the process isolation program of FIG. 2.

An electrographic marking apparatus 10 is shown in FIG. The present Invention is based on a special electrographic marking apparatus, such as e.g. a copier or printer. Still, it should be noted that, though the invention is suitable for use in such apparatus, but also with other types can be used by electrophotographic copiers and printers. The electrophotographic marker 10 includes a paper path from which Paper feed extends to the final treatment. The term also refers to paper also sheets, paper webs, transparent carrier elements, composite carrier elements or those made of laminates.

Since devices of the type described herein are known, the present one is Description focused in particular on the elements that are part of the present Invention are or are directly related to it.

V₀= Haupt/Primärspannung (relativ zur Erdung) auf dem Fotoleiter, wie sie direkt nach der ersten Ladeeinrichtung gemessen wird. Sie wird manchmal auch als "Anfangsspannung" bezeichnet.

V_0(m) = Mittelwert der einzelnen V₀ Werte.

V_B = Elektrodenvorspannung der Entwicklereinheit.

To facilitate understanding, the following definitions are established:

V ₀ = main / primary voltage (relative to ground) on the photoconductor as measured directly after the first charging device. It is sometimes referred to as the "initial tension".

V _{0 (m)} = mean value of the individual V ₀ values.

V _B = electrode bias of the developer unit.

In the electrophotographic marking apparatus 10 shown in FIG. 1 there is a movable image bearing element, e.g. a light-conducting tape 18 around a variety of Tensioned rollers, one of which is driven by a motor, pass the belt at a number of processing stations of the printer. The image carrier element can also be designed as a drum. The logic and control unit (LCU) 24 which can include a digital computer, assigns a stored program successive actuation of the different processing stations or subordinate systems of the apparatus 10.

A charging station makes the belt 18 photosensitive by applying a uniform electrostatic charge of a predetermined primary voltage V ₀ to the surface of the belt. The power of the first charging station is regulated by a programmable controlled power supply 30, which in turn is controlled by the LCU 24 in order to set the primary voltage V _0, for example by controlling the electrical potential (V _Grid ) on a grid electrode 28b, which controls the movement of the charged ions which is caused by the operation of the charging pole wires 28a on the surface of the carrier element. In the present example, a negative electrical bias is present at the grid electrodes 28b, for example between -350 and -750 volts; a target bias can be -500 volts.

At an exposure station, the projected light from a write head 34 modulates the electrical charge on the photoconductive belt 18 to form a latent electrostatic image to generate a document to be copied or printed. The print head points preferably a series of light emitting diodes (LEDs) or another Light source, e.g. a laser or other exposure source to expose the photoconductive tape. The exposure takes place picture element (pixel) for picture element with a regulated in accordance with the signals from the LCU to the write head interface 32 Intensity, the write head interface being a programmable control unit includes. Alternatively, the exposure can be carried out by optical projection of an image of a Document made on the photoconductor.

If an LED or other electro-optical exposure source is used, the image data to be recorded from a data source 36 for generating electrical Image signals, e.g. from a computer, a document scanner, a memory or a data network. Signals from the data source and / or LCU can also output control signals to a writer network, etc.

The movement of the belt 18 in the direction of arrow A leads the areas that are latent carry electrostatographic charge images, past a developer station 38. The The toner or developer unit has one (several in different colors) or several Magnetic brushes next to, but at a distance from the belt. Magnetic brush developer units are known from US 4,473,029 and 4,546,060.

The LCU 24 optionally operates the developer unit in relation to the areas of the image gliding past that carry the latent images. The Magnetic brush either in contact with or at a short distance from belt 18 brought. The charged toner particles of the contacted magnetic brush are called Image is drawn onto the latent image pattern to develop the pattern. In doing so also developed the calibration marks used for process control.

As is known from the prior art, the conductive parts of the developer unit, such as conductive application cylinders, act as electrodes. The electrodes are connected to a variable supply of DC potential V _B , which is regulated by a programmable controller 40. The details regarding the developer units are set out using an example, but are not essential to the invention.

In this example, the development corresponds to a DAD process (DAD = development of the discharged area), in which negatively charged toner particles alternatively in relative Develop discharged areas of the light guide element. Other types of Developer units are known and can also be used.

A transmission unit 46, as is also known, is provided to transmit one Recording sheet S in register with the image in contact with the light-guiding element bring. In this way the image is placed on a recording sheet, e.g. made of paper, or transfer a plastic sheet. Alternatively, the image can first be on an intermediate element and then transferred to the recording sheet. In the embodiment in FIG. 1 the transmission unit comprises a transmission corona charger 47.

The toner image is transferred electrostatically with a suitable voltage, which is applied to the transfer charger 47 to supply a constant current generate as described below. The back of the receiver sheet is in this Example charged with a positive charge by the transfer charging device, contacts the toner image on the photoconductor element during the recording sheet in order to Drag the toner image onto the recording sheet.

After the transfer, the recording sheet can be made using a known (not )) non-stick corona charger can be released from the belt 18. A Cleaning brush 48 or a knife is also arranged downstream of the transmission unit provided to remove the toner from the belt 18 so as to be reusable the surface for forming additional images is made possible. To remove Lightening the toner residue and other particles from the brush 48 is common a charging device 43 is provided, in this case positive charge on the Neutralize light guide element or the electrostatic adhesion of the remaining particles to reduce the volume 18. The tension of cleaning and Preparation charger is controlled by a power supply 42. While separate power supplies for each charger can be shown, one Power supply with several supply lines instead of several Power supply devices are used.

After transferring the unfixed toner images to a recording sheet, the Receiving sheet transported to a melting unit 49, on which the image is fixed.

A densitometer 76 is between the developer unit 38 and the transfer unit 46 arranged. The densitometer 76 monitors the development of the areas of the light-conductive tape 18, as is known from the prior art.

A second sensor, which is also preferably provided for process control, is an electrostatic voltmeter 50. A voltmeter is preferably located downstream of the first charging station 28 in order to provide readings of measured V ₀ s or V _{0 (m)} s. The output V _{0 (m)} s and densities, which the densitometer 76 determines, are fed to the LCU 24, which generates new setpoints for E ₀ , V ₀ and the actuation of the toner replenishment in accordance with a process control program.

In addition, the LCU 24 provides overall control of the device and its different child systems. Programming commercially available Microprocessors are familiar to the person skilled in the art. The following revelation aims to enable a programmer to create a suitable control program for to write such a microprocessor.

The logical links described in this document can be left out of microprocessors also from or in cooperation with non-programmable (hardware) or programmable logic devices can be created. To the precisely control the timing of the various processing facilities, are usually encoders in conjunction with indicators on the photoconductor used to provide timely signals indicating the frame areas and their position show in relation to the different units. Other types of control for timing of operations can also be used.

2 shows a block diagram of a typical LCU 24. The typical LCU 24 includes a temporary data storage, the central processing unit 154, the Timing and cycle control unit 156, the process isolation program 155 and the stored program control 158. Data input and output takes place sequentially based on or under the supervision of the program control.

Input data is either stored in one by the input signal latch 160 Input data processor 162 fed or by an interrupt signal processor 164. The input signals are from various switches, sensors and analog-to-digital Transducers that are parts of apparatus 10, derived from or from external sources be passed on to him. The output data and control signals become immediate or fed into suitable output drivers 168 by a catch register 166. The Output drivers are connected to the appropriate subordinate systems.

The LCU 24 includes the "stop and regeneration" or "process isolation" routines to stop the electrophotographic process and to reset the Apparatus 10 to the normal printing configuration. The LCU 24 thus enables Isolate the successive steps of imaging so that the respective Steps can be examined individually. The LCU holds the electrophotographic Process under the control of the LCU optionally at any point under one Variety of predetermined points. When the electrophotographic process starts one of these predetermined points is stopped, an on-site engineer can resulting product and the machine configuration at the predetermined point investigate to malfunction of a particular child system or Identify image irregularities.

Stopping the electrophotographic process by the LCU 24 is one to distinguish traditional "hard stop". A hard stop is a complete stop of the Apparatus. In the case of a hard stop, the operator usually has to intervene and some Carry out regeneration steps. A hard stop usually includes a inevitable complete reconfiguration of the system before another step of the electrophotographic process can be done. In contrast, the Points where the process isolation program stops, different parts to continue working on the apparatus. In addition, the following can Regeneration process requirements of apparatus 10 when controlled stopping is essential be reduced.

In Fig. 3 it is shown that the process isolation program the usual electrophotographic marking process to a predetermined point at which the marking process ends with a command from the LCU 24 becomes. This is not the case with the hard stops or the emergency stops due to a change in the apparatus, e.g. opening a door or a paper jam equate. If the LCU 24 determines the stopping of the marking process, there is not necessarily a hard stop or emergency stop of the relevant subordinate Systems. In the case of a configuration, the LCU 24 puts the apparatus 10 back on normal printing operation, initiates the subsequent printing and ends the subsequent one Printing at a predetermined location after the first termination. Consequently the process isolation program enables an investigation of the Marking process product at a variety of steps during the Marking process. The process isolation program can be configured to an automatic examination on a number of successive steps causes.

1. "Kalibrierungsmarkenstop" (zwischen zwei aufeinanderfolgenden Bildern) am Densitometer. Wenn die Kalibrierungsmarke am Densitometer 76 angehalten wird, kann das Tonen der zwei aneinandergrenzenden latenten Bilder untersucht werden.

2. "Nahtstellenstop" (zwischen zwei Bildern) bei der Übertragung. Dieser Stop ermöglicht eine Untersuchung der Naht.

3. "Transport-Stop". Dieser Stop erlaubt das Überprüfen des Bildes nach der Übertragung.

4. "Einschmelzvorrichtung-Stop". Dieser Stop erlaubt das Überprüfen des Bildes in der Einschmelzvorrichtung.

5. "Ausgangspfad-Stop". Dieser Stop erlaubt das Überprüfen des Bildes, nachdem es eingeschmolzen wurde.

Common points at which a stop occurs:

1. "Calibration mark stop" (between two successive images) on the densitometer. When the calibration mark is stopped on the densitometer 76, the toning of the two contiguous latent images can be examined.

2. "Interface stop" (between two images) during the transfer. This stop enables the seam to be examined.

3. "Transport stop". This stop allows the image to be checked after transmission.

4. "Melting device stop". This stop allows the image to be checked in the melting device.

5. "Exit Path Stop". This stop allows the image to be checked after it has been melted down.

The stops can be preprogrammed in the LCU 24, so that they are only carried out by one Engineer can be selected on site.

In addition, the present invention enables programming of a stop on everyone given point in the electrophotographic process. For example, can be a certain Sheet number can be programmed in a print job by an engineer on site.

The selected sheet of the print job can be placed at any point before the Registering should be stopped for an investigation of the paper path before the To enable image transmission. It is similar with duplex print jobs where one programmable stop for arches, apart from the first few arches, may be provided can, causing the examination of the duplex paper path before or after the second Transmission is made possible.

Because the predetermined stop of the electrophotographic process for any one Sheet of the print job is programmable, examining the paper path up for finishing is possible by placing a print job of appropriate length in Connection with the selection of the arc to be stopped is selected. In the This description includes the electrophotographic process in the Print operation of the entire paper path, including the finishing steps. By both the stops and the configuration of the apparatus at the predetermined Stops are controlled, the apparatus 10 is triggered by hard stop Stresses kept free. Complications in dealing with it also become corresponding avoided with the material that comes with hard stops.

The stop initiated by the LCU 24 originates from the LCU 24 rather than being a Response to an incident in the apparatus, e.g. opening a door, removing a tray or a stop command entered by the user.

The regeneration process works together with the predetermined stop point and can restore the apparatus to a normal process status or a process sequence for stop the subsequent stopping by the engineer on site.

List of reference numbers

10

marking machine

18

light-conducting tape

24

Logic and control unit (LCU)

28

first charging station

28a

Aufladepoldrähte

28b

grid electrodes

30

power supply

32

interface

36

Data Source

38

developer unit

40

programmable control

42

power supply

43

loader

46

transmission unit

47

corona charger

48

brush

49

Einschmelzeinheit

50

voltmeter

51

power supply

76

densitometer

154

central processing unit

155

Process isolation program

156

Timing and cycle control unit

158

saved program control

160

Input signal buffers

162

Input data processor

164

Interrupt signal processor

166

latch

168

output driver

S

arc

Claims (10)

Electrophotographic marker with
a logic and control unit (24) which is set to (i) stop a printing operation of the marking apparatus (10) at a predetermined point before the completion of the printing operation and (ii) issue a regeneration command corresponding to the stop set the machine back to normal printing. An electrographic marking apparatus according to claim 1,
characterized in that the predetermined point corresponds to a copy of a plurality of copies, a time or a location on the paper path. An electrographic marking apparatus according to claim 1,
characterized in that the logic and control unit (24) comprises a regeneration command associated with each predetermined point. The electrographic marking apparatus according to claim 3,
characterized in that the connection is a one-to-one correspondence. An electrographic marking apparatus according to claim 1,
characterized in that the regeneration command is connected only to the predetermined point. A method of operating an electrophotographic marking apparatus comprising the step of:
Initiating the completion of a normal printing operation setting of an electrophotographic marking apparatus (10) at a predetermined point before the completion of the electrophotographic process by an LCU (24). The method of claim 6, further comprising resetting the electrophotographic marker (10) in response to stopping with respect to the predetermined point. The method of claim 6, further comprising stopping the electrophotographic process on a particular copy from a predetermined number of copies, a time or a location on one Includes paper path. Method for operating an electrophotographic marking apparatus, the has a logic and control unit, which comprises the following steps: optionally stopping normal printing operation at a predetermined point by a preprogrammed command from an LCU (24) before the termination of the electrophotographic marking process and preventing an emergency stop or a hard stop response from the logic and control unit (24). The method of claim 9, further comprising initiating regeneration of the electrophotographic marking apparatus (10) to a normal one Print operation that corresponds to the command from the LCU (24).

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