EP1047980B1 - Printing and photocopying device and method whereby one toner mark is scanned at at least two points of measurement - Google Patents

Printing and photocopying device and method whereby one toner mark is scanned at at least two points of measurement Download PDF

Info

Publication number
EP1047980B1
EP1047980B1 EP99904782A EP99904782A EP1047980B1 EP 1047980 B1 EP1047980 B1 EP 1047980B1 EP 99904782 A EP99904782 A EP 99904782A EP 99904782 A EP99904782 A EP 99904782A EP 1047980 B1 EP1047980 B1 EP 1047980B1
Authority
EP
European Patent Office
Prior art keywords
toner
mark
flt
carrier
sensor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP99904782A
Other languages
German (de)
French (fr)
Other versions
EP1047980A1 (en
Inventor
Joseph Knott
André SCHWARZKOPF
Peter Bremmer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Canon Production Printing Germany GmbH and Co KG
Original Assignee
Oce Printing Systems GmbH and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Oce Printing Systems GmbH and Co KG filed Critical Oce Printing Systems GmbH and Co KG
Publication of EP1047980A1 publication Critical patent/EP1047980A1/en
Application granted granted Critical
Publication of EP1047980B1 publication Critical patent/EP1047980B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
    • G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
    • G03G15/0822—Arrangements for preparing, mixing, supplying or dispensing developer
    • G03G15/0848—Arrangements for testing or measuring developer properties or quality, e.g. charge, size, flowability
    • G03G15/0849—Detection or control means for the developer concentration
    • G03G15/0855—Detection or control means for the developer concentration the concentration being measured by optical means
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/50—Machine control of apparatus for electrographic processes using a charge pattern, e.g. regulating differents parts of the machine, multimode copiers, microprocessor control
    • G03G15/5033—Machine control of apparatus for electrographic processes using a charge pattern, e.g. regulating differents parts of the machine, multimode copiers, microprocessor control by measuring the photoconductor characteristics, e.g. temperature, or the characteristics of an image on the photoconductor
    • G03G15/5041—Detecting a toner image, e.g. density, toner coverage, using a test patch
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G2215/00—Apparatus for electrophotographic processes
    • G03G2215/00025—Machine control, e.g. regulating different parts of the machine
    • G03G2215/00029—Image density detection
    • G03G2215/00033—Image density detection on recording member
    • G03G2215/00037—Toner image detection
    • G03G2215/00042—Optical detection

Definitions

  • the invention relates to a device for printing or copying, wherein at least one toner mark on a toner carrier to check and adjust the toner area coverage is colored with toner.
  • the invention further relates to a Process for printing or copying.
  • a conventional printer or copier has a toner carrier for example a photoconductor; on which a latent Image, for example by exposure, is generated.
  • a Developer station is also used to color the latent image Toner.
  • This developer station contains a developer mixture from toner and carrier, for example magnetic iron particles, with an adjustable amount of toner.
  • To cover the toner area to be able to check and adjust is on the toner carrier a toner mark colored with toner and scanned this toner mark, for example with the help of a Reflex sensor.
  • the factors c to f are relative for a certain device type constant device parameters.
  • the factors a and b are interdependent; the toner supply in the developer zone depends on the Toner concentration, so that the degree of coloration of the latent Image is determined by the toner concentration. This degree of coloring or the toner area coverage is proportional for toner concentration.
  • the setting is made for previous printers or copiers the toner area coverage by measuring the toner mark, for example with the help of a reflex sensor.
  • the signal of the The reflex sensor then serves as a measure of the area coverage, i.e. the darker the coloring of the toner mark with toner, the more the signal level of the voltage of the receiver is lower, which the reflected radiation is detected.
  • This signal level is but also the reflection behavior of the toner and the surface the toner carrier, e.g. depends on the photoconductor surface.
  • the tolerances of the reflex sensor that the Toner mark scans to be noted. Therefore it is state of the art Technology, an individual setting for each printer the toner material, the developer station, the toner carrier etc. to make.
  • a toner density sensor has two toner marks a photoconductor drum.
  • the sensor contains two photo receivers, which is the reflectance of the two toner marks evaluate.
  • the toner marks are transverse to the direction of movement arranged the photoconductor drum, the one toner mark a high toner density and the other toner brand a low one Has toner density.
  • a bias for the developer unit is set.
  • From US-A-5,410,388 is a device or a method known for electrographic printing or copying, at a densitometer at two successive measuring locations an elongated toner mark the respective area coverage determined using infrared radiation. If between the Coverage in the front area of the toner mark and the there is a difference at the rear of the toner mark manifests itself in a different degree of reflection, so parameters of the developer process are simulated, for example, the toner concentration can be changed. Is the difference in reflectivity or the difference in the values of the area coverage equal to zero, so the development process leave unchanged.
  • the invention uses an effect that in the coloring of a full area in the direction of movement of the toner carrier.
  • Two component developer mixes occur.
  • the toner supply is initially large, which leads to a high area coverage. If this first toner supply is transferred to the toner carrier, new toner must first be conveyed through the developer rollers be what at low toner levels too leads to a decrease in area coverage. After the initial The drop in toner supply will then be along the length of the toner mark seen the toner supply remain constant and so also set a constant fan coverage.
  • the colored toner mark is in the direction of movement of the toner carrier seen on at least two successive measured values by at least one sensor scanned and the respective area coverage at these measuring locations mapped as electrical signals.
  • the proportion of toner in the developer mixture set. So it won't be the absolute level of the signal of the sensor, but along the toner mark measured difference in the signals or the quotient of the Signals. This difference or the quotient is extensive regardless of the reflectivity of the toner used, so that no different for different types of toner Settings must be made.
  • the reflectivity the surface of the toner carrier for example the Surface of a photoconductor drum or that of a carrier material from paper on which the toner mark is printed and then is scanned, has little impact on the result, especially then, as explained in more detail below, a measurement of the reflection behavior of the respective Surface is made.
  • An embodiment is characterized in that the Difference or the quotient of the signals at the two Measuring locations is compared with a target value, and that a controller controls a conveyor depending on the comparison, which feeds toner to the developer station.
  • a control system is created which ensures that the printer is always in an optimal operating condition high quality printing result is kept.
  • the control process for a certain undertone, i.e. the Difference is greater than zero or the quotient is not equal One, inserts, is through the subsequent control process ensures that an operating condition with over-toning not set because of a certain control deviation from the setpoint remains.
  • a timing controller is preferably used as the controller used the conveyor between an OFF state and switches an ON state back and forth.
  • the invention is of a fixed Scanning sensor, which is preferably the same sensor that the Scans the toner mark at the two measuring locations, the reference time found a reference point on the toner mark past the scanning sensor.
  • a reference point preferably the leading edge or the trailing edge of the toner mark used.
  • Scanning these locations then takes place for each toner mark with respect to the reference point in defined distances to this reference point.
  • the part of the invention described is preferably used if the evaluation of the electrical signals according to the previously described facility and the process takes place. He can however, can also be used to advantage to the location of a toner mark to be scanned at two measuring locations.
  • Fig. 1 shows a rectangular toner mark 10, the longitudinal extent in the direction of movement of a photoconductor drum lies.
  • the toner mark 10 provided with toner becomes two Measuring locations a1, a2 scanned. Due to the longitudinal movement of the Photoconductor drum results from a circular beam spot an areal extension of the measuring locations a1, a2 Kind of an elongated hole.
  • the measurement location a1 lies approximately in the middle of the first third and the measurement location a2 lies approximately in the middle the last third of the toner mark 10.
  • Figure 1 on the right is a diagram of the course of the voltage U of a radiation receiver over the length L of the toner mark 10 shown.
  • the radiation receiver (not shown) detects that of the toner mark 10 and the surface the photoconductor drum (also not shown) reflected Radiation and converts this if necessary after amplification into a voltage U um.
  • a first section 12 of the curve is radiation from the reflex sensor from the bare photoconductor surface with high reflectivity reflected, and there is a maximum voltage level Um, which is used as the reference level.
  • the Radiation sensor the front edge 10a of the toner mark 10, wherein the reflected radiation and thus also the voltage U decrease.
  • section 14 there is a minimum of the voltage curve, when the beam spot passes the leading edge 10a lies completely within the toner mark 10.
  • section 16 which by detection of the measurement location a1 is marked.
  • the course of tension increases slightly in this area. The reason for that will be explained below.
  • the measurement spot detects the Trailing edge 10b.
  • the voltage U rises again until in section 24 it again reaches the maximum value Um Has. According to the invention is shown in the figure Difference value ⁇ U evaluated.
  • the middle ones Voltage values U in the measuring locations a1 and a2 are taken into account.
  • FIG. 2 a diagram shows that the toner supply TA over the length of a full area, such as the toner mark 10, in the counter-development principle decreases.
  • Photo conductor drum FLT and developer roller EW in opposite directions Direction of rotation, as shown schematically in Figure 2 below is.
  • Developer roller EW reached, so there are many at first Toner particles for transfer to the FLT photoconductor drum ready, so there is a high toner supply TA.
  • After delivery of the first toner particles depletes the toner supply TA, and only as many toner particles are transferred as conveyed through the developer station to the developer roller EW become.
  • the drop in the toner supply TA is around in the initial range the steeper the lower the toner concentration TK.
  • Corresponding the difference in reflection behavior is also greater at the two measuring locations a1 and a2 and accordingly consequently the differential voltage ⁇ U is also greater.
  • Figure 3 shows a similar characteristic field as Figure 2, however for a synchronous development principle in which the directions of rotation of FLT photoconductor drum and EW developer roller are in the same direction. Because of the same directional rotation there is an increased at the rear edge 10b of the toner mark 10 Toner supply, since the developer roller EW with higher Speed as the FLT photoconductor drum rotates. Also here the measuring locations a1, a2 are once in the straight line part of the characteristic curve and once in the relatively steeply falling characteristic part to arrange.
  • Figure 4 relates to the characteristics of the toner supply TA over the Length of the toner mark 10 in the case of a co-reverse development principle, in which two developer rollers EW to each other be moved in opposite directions. There is a falling Characteristic curve of the toner supply TA near the front edge 10a and the rear edge 10b. In the sloping area this The measuring spot a1 or a1 'is to be arranged in a straight line Area of measurement location a2.
  • Figure 5 shows the relationship between area coverage FD a full area, such as a toner mark 10, and the toner supply TA in the developer zone.
  • the area coverage FD is low. This Coverage increases up to 100% when the toner supply increases. An area coverage of 100% means that the toner mark 10 is completely covered with toner and no defect is present, which shows through the surface of the photoconductor drum allows. If with an area coverage of Accordingly, 100% more toner layers are built up the blackening in printing does not increase any further.
  • FIG. 6 shows the arrangement of the measuring locations a1 and a2 in the counter-development principle.
  • a measuring location a1 in Area of the falling characteristic curve can be arranged during the other measurement location a2 in the rectilinear area of the characteristic to be ordered.
  • the characteristic curve 30 also shows intersection points Characteristic curves of different toner concentration TK, their the corresponding lengths L define the measuring locations for a2. For practical For reasons, the measurement location a2 becomes to the right of curve 30 at relatively large length L set.
  • FIG. 7 shows the relationship using a practical example between toner offer TA and area coverage FD uber the length L at different toner concentrations TK, where the lowest characteristic 34 is a low toner concentration Has.
  • the characteristic curves 36, 38, 40, 42 show increasing toner concentrations TK, the characteristic 42 being a very high one TK toner concentration affects, for example, 7 percent by weight and more.
  • the toner mark 10 has a typical one Length 1 from 8 to 16 mm and a width b from 4 to 10 mm. It differences ⁇ TA im result at the measuring locations a1 and a2 Toner supply, which with increasing toner concentration TK lose weight.
  • FIG. 8 shows the relationship between the voltage U measured by the radiation receiver at the various measuring locations a1, a2 for a black toner with low reflectivity and a red toner with relatively high reflectivity via the toner concentration TK, which is plotted in percent by weight.
  • the maximum voltage Um is obtained when the voltage receiver measures the radiation reflected from the bare surface of the photoconductor drum.
  • the characteristic curves for the red toner and the black toner show the voltage values as measured at the measuring locations a1 and a2.
  • the vertical dashed area corresponds to the respective voltage difference ⁇ U. It depends on the reflectivity of the respective toner.
  • R T is the reflectivity of the respective toner
  • R FLT is the reflectivity of the surface of the photoconductor drum
  • K is a device-side constant for a predetermined area coverage, for example close to 100%.
  • the reflection ratio R T / R FLT can be determined for each toner color and for each photoconductor drum and can then be taken into account in an evaluation, for example in the form of a correction table.
  • the respective voltage difference ⁇ U can then be corrected to take into account different toner types.
  • the ratio of R T / R FLT is very small, since the reflectivity of the respective toner is negligible compared to the reflectivity of the surface of the photoconductor drum.
  • the value R T / R FLT about 1/300 for black toner, and 1/10 is highly reflective toner such as yellow or red toner. The error resulting from the different reflectivities of different toner colors is therefore relatively small.
  • Figure 9 shows a comparison of the reflectivity different types of toner, as expressed by the characteristic curve 46, assuming an area coverage FD close to 100% becomes. The result is shown in the diagram below in FIG. 9 control taking into account the voltage difference ⁇ U shown. A value is specified as the setpoint, where the area coverage FD should be close to 100%. Independently of the absolute reflectivity and the absolute values the voltage U generated by the radiation sensor results for different colored toners a relatively constant value of the area coverage FD. The characteristic of the toner concentration TK, however fluctuates for the different toner colors.
  • FIG. 10 shows the schematic structure of a printing device, in which the invention is implemented.
  • a photoconductor drum FLT turns towards the Arrow P1, wherein a toner image is printed on single sheets 50 becomes.
  • a developer station 52 contains a container 54, in which the developer mixture of toner in carrier is processed.
  • a developer roller 56 transfers the toner on the surface of the FLT photoconductor drum.
  • the photoconductor drum FLT and developer station 52 operate on the Counter-development principle, i.e. the directions of rotation of the The developer roller 56 and the photoconductor drum FLT are each other opposed.
  • a toner conveying device 58 which comes from a reservoir Toner a toner cross feed 60 doses. This toner cross feed 60 delivers the toner to the container 54 from.
  • the toner delivery device 58 includes a drive motor, by a two-point controller 62 in the operating state Is switched ON or OFF.
  • a toner mark 10 is provided on the photoconductor drum FLT and is scanned with the aid of a reflex sensor 64.
  • This reflex sensor 64 contains an LED 66 which emits monochromatic infrared radiation.
  • the use of infrared radiation has the advantage that this radiation reacts less sensitively to the different toner colors, so that their reflectivity is less important in the result.
  • white interference light can be suppressed better by using infrared radiation.
  • the LED 66 is supplied with the current I L from a controllable current source 68.
  • a glass cover 72 is arranged between the photoconductor drum FLT and the reflex sensor 64, which prevents contamination by toner particles.
  • the emitted beam 74 is reflected differently.
  • the reflected radiation is composed of a portion 76 that originates from the surface of the photoconductor drum FLT.
  • a further radiation component 78 results due to the reflection on the glass cover 72.
  • a radiation component 80 which results from the reflection on the toner particles.
  • the radiation reflected overall by the toner mark 10 is detected by a receiving device 82 which contains a receiving diode.
  • the value ⁇ U is compared with a setpoint Us on the controller 62. If ⁇ U is larger than Us, the toner delivery device becomes 58 switched to the ON state and as long as toner promoted until the deviation between ⁇ U and Us approaches Is regulated zero.
  • switch 84 turns towards of arrow 86 switched, which makes the controllable power source 68 is controlled via the controller 62.
  • this adjustment phase a standardization on the reflectivity of the bare surface of the FLT photoconductor drum.
  • the bare surface of the photoconductor drum FLT illuminated by the reflex sensor 64 and in the receiving device 82 the associated voltage value U is measured.
  • the controllable current source 68 is now set so that a constant maximum value Um in the receiving device 82 established. With this setting, the toner mark will later become 10 scanned. By doing this, that the reflectivity of the surface of the photoconductor drum less important in the result because that different reflection behavior is based on the value Um normalized.
  • a transverse to the direction of rotation P1 of the photoconductor drum FLT Character generator arranged in front of the developer station 52 (not shown) writes the latent image or latent ones Images for a toner brand 10 or more toner brands on the surface of the FLT photoconductor drum.
  • the line generator and also the reflex sensor 64 are generally detachable installed, whereby installation tolerances result. these can add up so that the distance along the circumference of the photoconductor drum FLT between character generator and reflex sensor 64 typically fluctuates up to 2 mm.
  • Usually a timer is used to scan the toner marks 10. With the start of writing the latent image a start time is determined by the character generator. Due to the constant rotation speed of the photoconductor drum FLT and the known distance between Line generator and reflex sensor 64 becomes a delay time tm determined from which the sampling time for the toner mark 10 results from the reflex sensor 64.
  • FIG. 11 shows the voltage curve U as the toner mark passes 10 on the reflex sensor 64.
  • the course corresponds to that according to Figure 1.
  • the scanning of the toner mark 10 takes place within a time frame ZR at times T1 to T16.
  • To each Raster times T1 to T16 four samples are obtained, which are fed as digital values to a computer control.
  • the mean value of the 16 samples determined at each time T1 to T16 are used.
  • the averaged samples are stored in a memory cached.
  • the time frame ZR begins at the raster time T1 after expiry the delay time tm.
  • Methods are called measured values, from which the difference is then or the quotient are determined, averaged samples won the times T4 to T7 and T10 to T13.
  • the averaged Samples at times T4 to T7 and T10 up to T13 are again averaged to account for the significant amount of interference to be filtered out in the signals by averaging.
  • the values obtained in this way for the measuring locations a1 and a2 are then further processed.
  • the time frame ZR with respect to the Delay time tm shifted and each time T1 the voltage U sampled.
  • This shifting is done iteratively per toner mark by a time interval between the times T1 and T2.
  • the number of move steps required are to determine the voltage Uh, then indicates by how much the delay time tm has to be corrected by the To scan toner mark 10 at the measuring locations a1, a2, their position a defined distance to the front edge 10a or to the rear edge 10b of the toner mark 10.
  • Sampling at the time T1 is chosen because of interrupt runtimes the interrupt-controlled generation of the times T1 to T16 later times can vary in time. It should also be pointed out here that in FIG Voltage curve U reproduced in a vertically compressed state is; the voltage Uref is much higher in with respect to the voltage Utm as reproduced in the course.
  • Figure 12 shows the state around which the time frame ZR so far has been shifted until the time T1 the voltage Uh to investigate.
  • the number of times to find the voltage Uh required shift clocks is a measure of how much the delay time tm is to correct the toner mark 10 or the toner marks at the predetermined measuring locations a1, a2 scan.
  • the procedure described for determining the exact location of the Toner mark 10 will appear every time the printer is first set up or the copier applied. With this setting, a Large number of toner marks printed on the FLT photoconductor drum, to achieve a high precision in the setting.
  • the method steps mentioned can also be specified in predetermined Intervals, e.g. at intervals of one hour of operation, or each time the printer is turned on or copier (set up) can be used.
  • the embodiment shown can be within the scope of the invention amend.
  • the sensor 64 the toner mark 10 after transfer printing onto a carrier material, for example Paper, palpate.
  • a carrier material for example Paper, palpate.
  • the reflectivity of the carrier material standardized.
  • Another one Variant can instead of a photoconductor drum a photoconductor tape be used. Black toner material, colored toner material, one made of toner materials with different basic colors mixed toner or a transparent toner material can be used. This variant is described for example in WO98 / 39691 A1.

Description

Die Erfindung betrifft eine Einrichtung zum Drucken oder Kopieren, wobei auf einem Tonerträger mindestens eine Tonermarke zum Überprüfen und Einstellen der Toner-Flächendeckung mit Toner eingefärbt wird. Ferner betrifft die Erfindung ein Verfahren zum Drucken oder Kopieren.The invention relates to a device for printing or copying, wherein at least one toner mark on a toner carrier to check and adjust the toner area coverage is colored with toner. The invention further relates to a Process for printing or copying.

Ein herkömmlicher Drucker oder Kopierer hat einen Tonerträger, beispielsweise einen Fotoleiter; auf welchem ein latentes Bild, beispielsweise durch Belichten, erzeugt wird. Eine Entwicklerstation dient zum Einfärben des latenten Bildes mit Toner. Diese Entwicklerstation enthält ein Entwicklergemisch aus Toner und Träger, beispielsweise magnetische Eisenpartikel, mit einem einstellbaren Anteil an Toner. Um die Toner-Flächendeckung überprüfen und einstellen zu können, wird auf den Tonerträger eine Tonermarke mit Toner eingefärbt und diese Tonermarke abgetastet, beispielsweise mit Hilfe eines Reflexsensors.A conventional printer or copier has a toner carrier for example a photoconductor; on which a latent Image, for example by exposure, is generated. A Developer station is also used to color the latent image Toner. This developer station contains a developer mixture from toner and carrier, for example magnetic iron particles, with an adjustable amount of toner. To cover the toner area to be able to check and adjust is on the toner carrier a toner mark colored with toner and scanned this toner mark, for example with the help of a Reflex sensor.

Die Toner-Flächendeckung bei einem solchem Zweikompcnentenentwicklungssystem ist im wesentlichen durch die folgenden Faktoren bestimmt, nämlich

  • a) durch das Tonerangebot in der Entwicklerzone, d.h. an der Berührungsfläche von Entwicklerstation und Oberfläche des Tonerträgers;
  • b) durch die Tonerkonzentration im Entwicklergemisch;
  • c) durch das elektrostatische Ladeverhalten der Oberfläche der Fotoleitertrommel;
  • d) durch das Trieboverhalten des Entwicklergemisches, d.h. der Haftkraft zwischen Trägerteilchen und Toner;
  • e) durch die Form und Größe der Teilchen im Entwicklergemisch;
  • f) und durch die Aktivität der Tonerteilchen, die von der Entwicklerwalze in der Entwicklerzone angeboten werden.
    • The toner area coverage in such a two-component development system is essentially determined by the following factors, namely
  • a) through the toner supply in the developer zone, ie at the contact surface of the developer station and the surface of the toner carrier;
  • b) by the toner concentration in the developer mixture;
  • c) by the electrostatic charging behavior of the surface of the photoconductor drum;
  • d) by the drive behavior of the developer mixture, ie the adhesive force between carrier particles and toner;
  • e) by the shape and size of the particles in the developer mixture;
  • f) and by the activity of the toner particles offered by the developer roller in the developer zone.

    • Für einen bestimmten Gerätetyp sind die Faktoren c bis f relativ konstante Geräteparameter. Im Hinblick auf die Faktoren a und b ist eine gegenseitige Abhängigkeit gegeben; das Tonerangebot in der Entwicklerzone ist nämlich abhängig von der Tonerkonzentration, so daß der Einfärbungsgrad des latenten Bildes von der Tonerkonzentration bestimmt wird. Dieser Einfärbungsgrad oder die Toner-Flächendeckung ist proportional zur Tonerkonzentration.The factors c to f are relative for a certain device type constant device parameters. In terms of the factors a and b are interdependent; the toner supply in the developer zone depends on the Toner concentration, so that the degree of coloration of the latent Image is determined by the toner concentration. This degree of coloring or the toner area coverage is proportional for toner concentration.

    Bei bisherigen Druckern oder Kopierern erfolgt die Einstellung der Toner-Flächendeckung durch Messung der Tonermarke, beispielsweise mit Hilfe eines Reflexsensors. Das Signal des Reflexsensors dient dann als Maß für die Flächendeckung, d.h. je dunkler die Einfärbung der Tonermarke mit Toner ist, um so geringer ist die Signalhöhe der Spannung des Empfängers, welcher die reflektierte Strahlung erfaßt. Diese Signalhöhe ist jedoch auch vom Reflexionsverhalten des Toners und der Oberfläche des Tonerträgers, z.B. der Fotoleiteroberfläche abhängig. Weiterhin sind die Toleranzen des Reflexsensors, der die Tonermarke abtastet, zu beachten. Daher ist es Stand der Technik, für jeden Drucker eine individuelle Einstellung auf das Tonermaterial, die Entwicklerstation, den Tonerträger etc. vorzunehmen. Bei Änderung des Tonertyps und bei Austausch des Tonerträgers muß diese Einstellung immer wieder neu vorgenommen werden. Um die Einstellarbeit zu erleichtern, wurden in herkömmlichen Druckern Korrekturprogramme installiert, die bei externer Eingabe des Tonertyps und der Art der Fotoleitertrommel innerhalb gewisser Bandbreiten eine automatische Anpassung vornehmen. Trotz dieser Korrekturmaßnahmen ist das Ergebnis häufig unbefriedigend und es kann sich eine Übertonerung einstellen, bei der die Tonerschicht auf dem Tonerträger dicker als erforderlich ist, was zu einem übermäßigen Tonerverbrauch führt.The setting is made for previous printers or copiers the toner area coverage by measuring the toner mark, for example with the help of a reflex sensor. The signal of the The reflex sensor then serves as a measure of the area coverage, i.e. the darker the coloring of the toner mark with toner, the more the signal level of the voltage of the receiver is lower, which the reflected radiation is detected. This signal level is but also the reflection behavior of the toner and the surface the toner carrier, e.g. depends on the photoconductor surface. Furthermore, the tolerances of the reflex sensor that the Toner mark scans, to be noted. Therefore it is state of the art Technology, an individual setting for each printer the toner material, the developer station, the toner carrier etc. to make. When changing the toner type and when replacing of the toner carrier must make this setting again and again be made anew. To make adjustment work easier, correction programs were installed in conventional printers, the external input of the toner type and the type of Automatic photoconductor drum within certain bandwidths Make adjustment. Despite these corrective actions the result is often unsatisfactory and there may be one Set over toning where the toner layer is on the toner carrier thicker than necessary, resulting in excessive Toner consumption leads.

    Aus der DE-A-39 38 354 ist ein Bildaufzeichnungsgerät bekannt, bei dem ein Tonerdichten-Fühler zwei Tonermarken auf einer Fotoleitertrommel abtestet. Der Fühler enthält zwei Fotoenpfänger, die den Reflexionsgrad der beiden Tonermarken auswerten. Die Tonermarken sind quer zur Bewegungsrichtung der Fotoleitertrommel angeordnet, wobei die eine Tonermarke eine hohe Tonerdichte und die andere Tonermarke eine niedrige Tonerdichte hat. Abhängig vom Meßergebnis der Fotoempfänger wird eine Vorspannung für die Entwicklereinheit eingestellt.From DE-A-39 38 354 an image recording device is known where a toner density sensor has two toner marks a photoconductor drum. The sensor contains two photo receivers, which is the reflectance of the two toner marks evaluate. The toner marks are transverse to the direction of movement arranged the photoconductor drum, the one toner mark a high toner density and the other toner brand a low one Has toner density. Depending on the measurement result of the photo receiver a bias for the developer unit is set.

    Aus der US-A-5,410,388 ist eine Einrichtung bzw. ein Verfahren zum elektrografischen Drucken oder Kopieren bekannt, bei dem ein Densitometer an zwei aufeinanderfolgenden Meßorten einer langgestreckten Tonermarke die jeweilige Flächendeckung mithilfe von Infrarotstrahlung bestimmt. Wenn zwischen der Flächendeckung im vorderen Bereich der Tonermarke und dem hinteren Bereich der Tonermarke ein Unterschied besteht, welcher sich in einem unterschiedlichen Reflexionsgrad äußert, so werden Parameter des Entwicklerprozesses nachgestellt, beispielsweise kann die Tonerkonzentration geändert werden. Ist die Differenz im Reflexionsvermögen oder die Differenz in den Werten der Flächendeckung gleich Null, so wird der Entwicklerprozeß unverändert belassen.From US-A-5,410,388 is a device or a method known for electrographic printing or copying, at a densitometer at two successive measuring locations an elongated toner mark the respective area coverage determined using infrared radiation. If between the Coverage in the front area of the toner mark and the there is a difference at the rear of the toner mark manifests itself in a different degree of reflection, so parameters of the developer process are simulated, for example, the toner concentration can be changed. Is the difference in reflectivity or the difference in the values of the area coverage equal to zero, so the development process leave unchanged.

    Es ist Aufgabe der Erfindung, eine Einrichtung und ein Verfahren anzugeben, die bzw. das den Einstellaufwand verringert und ein relativ hochwertiges Druckergebnis erzielt.It is an object of the invention, a device and a method to specify, which reduces the adjustment effort and achieved a relatively high quality print result.

    Diese Aufgabe wird für Einrichtungen durch die Merkmale der Ansprüche 1 und 22 sowie für entsprechende Arbeitsverfahren durch die Merkmale der Ansprüche 13 und 30 gelöst. Vorteilhafte Weiterbildungen sind in den abhängigen Ansprüchen angegeben.This task is accomplished by the characteristics of the facilities Claims 1 and 22 and for corresponding working methods solved by the features of claims 13 and 30. advantageous Developments are specified in the dependent claims.

    Die Erfindung nutzt einen Effekt, der bei der Einfärbung einer vollen Fläche in Bewegungsrichtung des Tonerträgers bei Zweikomponentenentwicklergemischen auftritt. In Bewegungsrichtung des Tonerträgers gesehen ändert sich nämlich das Tonerangebot innerhalb der Entwicklerzone. Das Tonerangebot ist zunächst groß, was zu einer hohen Flächendeckung führt. Wenn dieses erste Tonerangebot an den Tonerträger übertragen ist, so muß erst neuer Toner durch die Entwicklerwalzen nachgefördert werden, was bei niedriger Tonerkonzentration zu einer Abnahme der Flächendeckung führt. Nach dem anfänglichen Abfall des Tonerangebots wird dann über die Länge der Tonermarke gesehen das Tonerangebot konstant bleiben und sich so auch eine konstante Fächendeckung einstellen. In diesem Zusammenhang spricht man von einem Verarmungseffekt in einer Vollfläche in Bewegungsrichtung des Tonerträgers. Dieser Verarmungseffekt macht sich in einer Verringerung der Flächendeckung bemerkbar, bis eine Sättigung erreicht ist, d.h. innerhalb der Verarmungszone die Flächendeckung 100% auf der Tonermarke ist. Bei diesem Grad der Flächendeckung ist die Tonermarke dicht mit Toner ohne Fehlstellen bedeckt - die Erhöhung der Schichtdicke des Toners ergibt keine zusätzliche Schwärzung bei einem schwarzen Toner. Die Schwankungen in der Flächendeckung längs der Tonermarke sind umgekehrt proportional zur Tonerkonzentration. Je höher die Tonerkonzentration, um so kleiner sind die Flächendeckungsunterschiede bzw. die Einfärbungsunterschiede auf der Tonermarke.The invention uses an effect that in the coloring of a full area in the direction of movement of the toner carrier Two component developer mixes occur. In the direction of movement seen from the toner carrier, namely the toner supply changes within the developer zone. The toner supply is initially large, which leads to a high area coverage. If this first toner supply is transferred to the toner carrier, new toner must first be conveyed through the developer rollers be what at low toner levels too leads to a decrease in area coverage. After the initial The drop in toner supply will then be along the length of the toner mark seen the toner supply remain constant and so also set a constant fan coverage. In this context one speaks of an impoverishment effect in one Full area in the direction of movement of the toner carrier. This impoverishment effect results in a reduction in area coverage noticeable until saturation is reached, i.e. within the depletion zone the area coverage 100% on the Toner brand is. At this degree of area coverage is Toner brand densely covered with toner without defects - the Increasing the layer thickness of the toner does not result in an additional one Blackening with a black toner. The fluctuations in the Area coverage along the toner mark is inversely proportional for toner concentration. The higher the toner concentration, the smaller the area coverage differences or Color differences on the toner mark.

    Bei der Erfindung wird nur die eingefärbte Tonermarke in Bewegungsrichtung des Tonerträgers gesehen an mindestens zwei aufeinanderfolgenden Meßerten durch mindestens einen Sensor abgetastet und die jeweilige Flächendeckung an diesen Meßorten als elektrische Signale abgebildet. Abhängig von der Differenz oder dem Quotienten der Beträge der Signale an diesen beiden Meßorten wird der Anteil an Toner im Entwicklergemisch eingestellt. Es wird also nicht die absolute Höhe des Signals des Sensors ausgewertet, sondern der längs der Tonermarke gemessene Unterschied in den Signalen bzw. der Quotient der Signale. Dieser Unterschied bzw. der Quotient sind weitgehend unabhängig vom Reflexionsvermögen des verwendeten Toners, so daß für unterschiedliche Tonertypen keine unterschiedlichen Einstellungen vorgenommen werden müssen. Auch das Reflexionsvermögen der Oberfläche des Tonerträgers, beispielsweise der Oberfläche einer Fotoleitertrommel oder die eines Trägermaterials aus Papier, auf das die Tonermarke gedruckt und dann abgetastet wird, geht nur gering in das Ergebnis ein, insbesondere dann, wenn wie weiter unten noch genauer erläutert, eine Einmessung auf das Reflexionsverhalten der jeweiligen Oberfläche vorgenommen wird.In the invention, only the colored toner mark is in the direction of movement of the toner carrier seen on at least two successive measured values by at least one sensor scanned and the respective area coverage at these measuring locations mapped as electrical signals. Depending on the difference or the quotient of the amounts of the signals thereon In both measuring locations, the proportion of toner in the developer mixture set. So it won't be the absolute level of the signal of the sensor, but along the toner mark measured difference in the signals or the quotient of the Signals. This difference or the quotient is extensive regardless of the reflectivity of the toner used, so that no different for different types of toner Settings must be made. Also the reflectivity the surface of the toner carrier, for example the Surface of a photoconductor drum or that of a carrier material from paper on which the toner mark is printed and then is scanned, has little impact on the result, especially then, as explained in more detail below, a measurement of the reflection behavior of the respective Surface is made.

    Wenn eine Einstellung des Anteils an Toner im Entwicklergemisch so vorgenommen wird, daß die Differenz nahe Null oder der Quotient nahe Eins ist, so wird nahezu keine Schwankung der Flächendeckung über die Länge der Tonermarke stattfinden. In diesem Betriebszustand ist eine optimale Einfärbung gewährleistet, ohne daß eine Übertonerung stattfindet.When adjusting the amount of toner in the developer mixture is made so that the difference is close to zero or the quotient is close to one, there is almost no fluctuation the area coverage over the length of the toner mark. In this operating state, an optimal coloring is guaranteed, without overtoning.

    Ein Ausführungsbeispiel ist dadurch gekennzeichnet, daß die Differenz oder der Quotient aus den Signalen an den beiden Meßorten mit einem Sollwert verglichen wird, und daß ein Regler abhängig vom Vergleich eine Fördervorrichtung ansteuert, die der Entwicklerstation Toner zufördert. Auf diese Weise wird ein Regelungssystem geschaffen, welches sicherstellt, daß der Drucker immer in einem optimalen Betriebszustand mit hochqualitativem Druckergebnis gehalten wird. Als Sollwert wird ein Wert nahe Null bei Auswertung der Differenz und ein Wert nahe Eins bei Auswertung des Quotienten gewählt. Wenn der Regelvorgang bei einer gewissen Untertonerung, d.h. die Differenz ist größer als Null bzw. der Quotient ist ungleich Eins, einsetzt, so ist durch den nachfolgenden Regelvorgang sichergestellt, daß ein Betriebszustand mit Übertonerung sich nicht einstellt, da eine gewisse Regelabweichung zum Sollwert verbleibt. Vorzugsweise wird als Regler ein Zeitpunktregler verwendet, der die Fördervorrichtung zwischen einem AUS-Zustand und einem EIN-Zustand hin und her schaltet.An embodiment is characterized in that the Difference or the quotient of the signals at the two Measuring locations is compared with a target value, and that a controller controls a conveyor depending on the comparison, which feeds toner to the developer station. In this way a control system is created which ensures that the printer is always in an optimal operating condition high quality printing result is kept. As a setpoint becomes a value near zero when evaluating the difference and a Value close to one selected when evaluating the quotient. If the control process for a certain undertone, i.e. the Difference is greater than zero or the quotient is not equal One, inserts, is through the subsequent control process ensures that an operating condition with over-toning not set because of a certain control deviation from the setpoint remains. A timing controller is preferably used as the controller used the conveyor between an OFF state and switches an ON state back and forth.

    Bei der vorgenannten Einrichtung und dem Auswertungsverfahren ist es wesentlich, daß die relative Lage der Meßorte auf der Tonermarke gleich bleibt. Mechanische Einbautoleranzen des Tonerträgers bzw. des Sensors können dazu führen, daß sich der Abstand zwischen Tonertrager und Sensor ändert. Auch beim Austausch des Tonerträgers oder des Sensors können sich derartige Lageveränderungen ergeben. Wenn nun der Sensor nach einer vorbestimmten Verzögerungszeit, in der die mit Toner eingefärbte Tonermarke nach dem Schreiben des latenten Bildes bis zum Erreichen des Sensors vorwärtsbewegt worden ist, durch den Sensor abgetastet wird, so wird nicht immer an denselben Meßorten der Tonermarke gemessen. Die Folge davon ist, daß die aus den elektrischen Meßsignalen der Sensoren gewonnene Einstellung nicht mehr optimal ist. Demgemäß wird in den Ansprüchen 22 und 30 eine Einrichtung und ein Verfahren angegeben, die bzw. das es erlaubt, die Tonermarke an Meßorten abzutasten, deren Lage in bezug auf die Tonermarke konstant bleibt.With the aforementioned facility and the evaluation procedure it is essential that the relative position of the measuring points on the Toner brand remains the same. Mechanical installation tolerances of the Toner carrier or the sensor can cause the distance between the toner carrier and the sensor changes. Also at Replacing the toner carrier or the sensor can be such Changes in location result. If now the sensor after a predetermined delay time in which the toner colored toner mark after writing the latent image has been moved forward until the sensor is reached, is sensed by the sensor, it is not always on the same Measuring locations of the toner mark measured. The consequence of this is that the obtained from the electrical measurement signals from the sensors Setting is no longer optimal. Accordingly, in the Claims 22 and 30 specified a device and a method, which allows the toner mark at measuring locations to scan, whose position with respect to the toner mark is constant remains.

    Gemäß diesem Aspekt der Erfindung wird von einem ortstfesten Abtastsensor, der vorzugsweise derselbe Sensor ist, der die Tonermarke an den zwei Meßorten abtastet, der Referenz-Zeitpunkt festgestellt, zu dem ein Referenzpunkt auf der Tonermarke am Abtastsensor vorbeiläuft. Als Referenzpunkt wird vorzugsweise die Vorderkante oder die Hinterkante der Tonermarke verwendet. Abhängig von diesem Referenz-Zeitpunkt können bei Kenntnis der Transportgeschwindigkeit des Tonerträgers die weiteren Zeitpunkte festgelegt werden, zu denen die zwei Meßorte abzutasten sind. Das Abtasten dieser Meßorte erfolgt dann je Tonermarke bezüglich des Referenzpunktes in definierten Abständen zu diesem Referenzpunkt.According to this aspect the invention is of a fixed Scanning sensor, which is preferably the same sensor that the Scans the toner mark at the two measuring locations, the reference time found a reference point on the toner mark past the scanning sensor. As a reference point preferably the leading edge or the trailing edge of the toner mark used. Depending on this reference point in time with knowledge of the transport speed of the toner carrier the further times at which the two measuring locations are to be scanned. Scanning these locations then takes place for each toner mark with respect to the reference point in defined distances to this reference point.

    Der beschriebene Erfindungsteil wird vorzugsweise eingesetzt, wenn die Auswertung der elektrischen Signale gemäß der vorher beschriebenen Einrichtung und dem Verfahren erfolgt. Er kann jedoch auch dann vorteilhaft eingesetzt werden, um die Lage einer an zwei Meßorten abzutastenden Tonermarke festzustellen.The part of the invention described is preferably used if the evaluation of the electrical signals according to the previously described facility and the process takes place. He can however, can also be used to advantage to the location of a toner mark to be scanned at two measuring locations.

    Ein Ausführungsbeispiel der Erfindung wird im folgenden anhand der Zeichnung erläutert. Darin zeigt

    Figur 1
    die Tonermarke mit zwei Meßorten sowie den Verlauf einer Sensorspannung über die Länge der Tonermarke,
    Figur 2
    ein Kennlinienfeld des Tonerangebots über die Länge einer Vollfläche beim Gegenlaufentwicklungsprinzip,
    Figur 3
    ein Kennlinienfeld nach Figur 2 für ein Gleichlaufentwicklungsprinzip,
    Figur 4
    ein Kennlinienfeld nach Figur 2 für ein Gleich-Gegenlaufentwicklungsprinzip,
    Figur 5
    den Zusammenhang zwischen Flächendeckung und Tonerangebot in der Entwicklungszone,
    Figur 6
    die Flächendeckung über die Länge einer Vollfläche bei unterschiedlichen Tonerkonzentrationen,
    Figur 7
    den Zusammenhang der Flächendeckung über die Länge einer Tonermarke für unterschiedliche Tonerkonzentrationen,
    Figur 8
    die von einem Reflexsensor abgegebene Spannung über die Tonerkonzentration für einen schwarzen und einen roten Toner,
    Figur 9
    das Reflexionsvermögen für verschiedene Tonerfarben und den Grad der Flächendeckung für diese verschiedenen Tonerfarben bei Regelung der Tonerkonzentration,
    Figur 10
    schematisch den Aufbau einer Druckeinrichtung, bei der die Erfindung realisiert ist,
    Figur 11
    Rasterzeitpunkte, zu denen der Verlauf der Sensor-spannung über die Länge der Tonermarke abgetastet und abgespeichert werden, und
    Figur 12
    das Abtasten beim Vorbeilauf der Hinterkante der Tonermarke am Reflexsensor.
    An embodiment of the invention is explained below with reference to the drawing. In it shows
    Figure 1
    the toner mark with two measuring locations and the course of a sensor voltage over the length of the toner mark,
    Figure 2
    a characteristic field of the toner supply over the length of a full surface with the counter-development principle,
    Figure 3
    2 shows a characteristic field according to FIG. 2 for a synchronous development principle,
    Figure 4
    2 shows a characteristic field according to FIG. 2 for a principle of counter-clockwise development,
    Figure 5
    the relationship between area coverage and toner supply in the development zone,
    Figure 6
    the area coverage over the length of a full area with different toner concentrations,
    Figure 7
    the relationship of the area coverage over the length of a toner mark for different toner concentrations,
    Figure 8
    the voltage emitted by a reflex sensor via the toner concentration for a black and a red toner,
    Figure 9
    the reflectivity for different toner colors and the degree of area coverage for these different toner colors when regulating the toner concentration,
    Figure 10
    schematically the structure of a printing device in which the invention is implemented,
    Figure 11
    Grid times at which the course of the sensor voltage over the length of the toner mark are scanned and stored, and
    Figure 12
    scanning as the trailing edge of the toner mark passes the reflex sensor.

    Fig. 1 zeigt eine rechteckförmige Tonermarke 10, deren Längsausdehnung in Bewegungsrichtung einer Fotoleitertrommel liegt. Die mit Toner versehene Tonermarke 10 wird an zwei Meßorten a1, a2 abgetastet. Aufgrund der Längsbewegung der Fotoleitertrommel ergibt sich bei einem kreisförmigen Strahlfleck eine flächenhafte Ausdehnung der Meßorte a1, a2 nach Art eines Langlochs. Der Meßort a1 liegt etwa in der Mitte des ersten Drittels und der Meßort a2 liegt etwa in der Mitte des letzten Drittels der Tonermarke 10.Fig. 1 shows a rectangular toner mark 10, the longitudinal extent in the direction of movement of a photoconductor drum lies. The toner mark 10 provided with toner becomes two Measuring locations a1, a2 scanned. Due to the longitudinal movement of the Photoconductor drum results from a circular beam spot an areal extension of the measuring locations a1, a2 Kind of an elongated hole. The measurement location a1 lies approximately in the middle of the first third and the measurement location a2 lies approximately in the middle the last third of the toner mark 10.

    In Figur 1 rechts ist in einem Diagramm der Verlauf der Spannung U eines Strahlungsempfängers über die Länge L der Tonermarke 10 dargestellt. Der Strahlungsempfänger (nicht dargestellt) erfaßt die von der Tonermarke 10 und der Oberfläche der Fotoleitertrommel (ebenfalls nicht dargestellt) reflektierte Strahlung und wandelt diese gegebenenfalls nach Verstärkung in eine Spannung U um. In einem ersten Abschnitt 12 des Kurvenverlaufs wird Strahlung des Reflexsensors von der blanken Fotoleiteroberfläche mit hohem Reflexionsvermögen reflektiert, und es ergibt sich ein maximaler Spannungspegel Um, der als Referenzpegel verwendet wird.In Figure 1 on the right is a diagram of the course of the voltage U of a radiation receiver over the length L of the toner mark 10 shown. The radiation receiver (not shown) detects that of the toner mark 10 and the surface the photoconductor drum (also not shown) reflected Radiation and converts this if necessary after amplification into a voltage U um. In a first section 12 of the curve is radiation from the reflex sensor from the bare photoconductor surface with high reflectivity reflected, and there is a maximum voltage level Um, which is used as the reference level.

    Wenn sich die Tonermarke 10 mit der Geschwindigkeit v in der angegebenen Pfeilrichtung vorwärts bewegt, so erfaßt der Strahlungssensor die Vorderkante 10a der Tonermarke 10, wobei die reflektierte Strahlung und somit auch die Spannung U abnimmt. Es ergibt sich in Abschnitt 14 ein Minimum des Spannungsverlaufs, wenn der Strahlfleck nach Vorbeilauf der Vorderkante 10a komplett innerhalb der Tonermarke 10 liegt. An den Abschnitt 14 schließt der Abschnitt 16 an, der durch Erfassen des Meßortes a1 gekennzeichnet ist. Der Spannungsverlauf nimmt in diesem Bereich leicht zu. Der Grund hierfür wird weiter unten erläutert. Es erfolgt eine weitere Zunahme der Spannung U im Abschnitt 18. Im Abschnitt 20 wird der Meßort a2 abgetastet. Im Abschnitt 22 erfaßt der Meßfleck die Hinterkante 10b. Aufgrund der hohen Reflexion der Oberfläche der Fotoleitertrommel steigt die Spannung U wieder an, bis sie im Abschnitt 24 wieder den maximalen Wert Um erreicht hat. Erfindungsgemäß wird der in der Figur eingezeichnete Differenzwert ΔU ausgewertet. Vorzugsweise werden die mittleren Spannungswerte U in den Meßorten a1 und a2 berücksichtigt.If the toner mark 10 at the speed v in the Moves forward indicated arrow, so the Radiation sensor the front edge 10a of the toner mark 10, wherein the reflected radiation and thus also the voltage U decrease. In section 14 there is a minimum of the voltage curve, when the beam spot passes the leading edge 10a lies completely within the toner mark 10. On section 14 is followed by section 16, which by detection of the measurement location a1 is marked. The course of tension increases slightly in this area. The reason for that will be explained below. There is a further increase of the voltage U in section 18. In section 20 the measuring point a2 scanned. In section 22, the measurement spot detects the Trailing edge 10b. Because of the high reflection of the surface of the photoconductor drum, the voltage U rises again until in section 24 it again reaches the maximum value Um Has. According to the invention is shown in the figure Difference value ΔU evaluated. Preferably the middle ones Voltage values U in the measuring locations a1 and a2 are taken into account.

    In der Figur 2 ist an Hand eines Diagramms dargestellt, daß das Tonerangebot TA über die Länge einer Vollfläche, wie beispielsweise der Tonermarke 10, beim Gegenlaufentwicklungsprinzip abnimmt. Bei diesem Gegenlaufentwicklungsprinzip haben Fotoleitertrommel FLT and Entwicklerwalze EW gegensinnige Drehrichtungen, wie unten in Figur 2 schematisch dargestellt ist. Wenn die Tonermarke 10 mit ihrer Vorderkante 10a die Entwicklerwalze EW erreicht, so stehen im ersten Moment viele Tonerteilchen zur Übertragung auf die Fotoleitertrommel FLT bereit, es besteht also ein hohes Tonerangebot TA. Nach Abgabe der ersten Tonerpartikel verarmt das Tonerangebot TA, und es werden lediglich so viele Tonerpartikel übertragen, wie durch die Entwicklerstation an die Entwicklerwalze EW nachgefördert werden. Es ergibt sich im Tonerangebot TA ein Abfall, wie dies durch die drei Kennlinien ausgedrückt wird, welche eine hohe Tonerkonzentration TK, eine mittlere Tonerkonzentration TK und eine niedrige Tonerkonzentration TK betreffen. Im Bereich dieses Abfalls ist ein Meßort, z.B. der Meßort a1, anzuordnen. Nach einer gewissen Länge ist die nachgeförderte Menge an Toner konstant - die Kennlinien verlaufen annähernd parallel zu einer gestrichelt eingezeichneten Sättigungskennlinie 26, bei der eine 100 % ige Einfarbung der Tonermarke 10 erfolgt ist, d.h. auch bei einer Erhöhung der Tonerteilchen pro Flächeneinheit ergibt sich bei einem schwarzen Toner keine zusätzliche Schwärzung beim Druck. In diesem Bereich der weitgehend parallel verlaufenden Kennlinien ist der Meßort a2 anzuordnen. Wie aus dem Kennlinienfeld zu erkennen ist, ist der Abfall des Tonerangebots TA im Anfangsbereich um so steiler, je niedriger die Tonerkonzentration TK ist. Entsprechend größer ist dann auch der Unterschied im Reflexionsverhalten an den beiden Meßorten a1 und a2 und entsprechend größer demzufolge auch die Differenzspannung ΔU.In FIG. 2, a diagram shows that the toner supply TA over the length of a full area, such as the toner mark 10, in the counter-development principle decreases. Have with this counter-development principle Photo conductor drum FLT and developer roller EW in opposite directions Direction of rotation, as shown schematically in Figure 2 below is. When the toner mark 10 with its leading edge 10a Developer roller EW reached, so there are many at first Toner particles for transfer to the FLT photoconductor drum ready, so there is a high toner supply TA. After delivery of the first toner particles depletes the toner supply TA, and only as many toner particles are transferred as conveyed through the developer station to the developer roller EW become. There is a waste in the TA toner supply, as expressed by the three characteristics, which a high toner concentration TK, a medium toner concentration TK and a low toner concentration TK concern. In the area of this waste there is a measuring point, e.g. the measurement location a1, to arrange. After a certain length is the post-funded Amount of toner constant - the characteristic curves run approximately parallel to a dashed saturation curve 26, in which a 100% inking of the toner mark 10 has taken place, i.e. even if the toner particles increase per unit area results with a black toner no additional blackening when printing. In this area of the largely parallel characteristic curves is the measuring point to arrange a2. As can be seen from the characteristic field is, the drop in the toner supply TA is around in the initial range the steeper the lower the toner concentration TK. Corresponding the difference in reflection behavior is also greater at the two measuring locations a1 and a2 and accordingly consequently the differential voltage ΔU is also greater.

    Figur 3 zeigt ein ähnliches Kennlinienfeld wie Figur 2, jedoch für ein Gleichlaufentwicklungsprinzip, bei dem die Drehrichtungen von Fotoleitertrommel FLT und Entwicklerwalze EW gleichsinnig sind. Aufgrund der gleichsinnigen Drehbewegung ergibt sich an der Hinterkante 10b der Tonermarke 10 ein erhöhtes Tonerangebot, da sich die Entwicklerwalze EW mit höherer Geschwindigkeit als die Fotoleitertrommel FLT dreht. Auch hier sind die Meßorte a1, a2 einmal im geradlinigen Kennlinienteil und einmal im relativ steil abfallenden Kennlinienteil anzuordnen.Figure 3 shows a similar characteristic field as Figure 2, however for a synchronous development principle in which the directions of rotation of FLT photoconductor drum and EW developer roller are in the same direction. Because of the same directional rotation there is an increased at the rear edge 10b of the toner mark 10 Toner supply, since the developer roller EW with higher Speed as the FLT photoconductor drum rotates. Also here the measuring locations a1, a2 are once in the straight line part of the characteristic curve and once in the relatively steeply falling characteristic part to arrange.

    Figur 4 betrifft Kennlinien des Tonerangebots TA über die Länge der Tonermarke 10 bei einem Gleich-Gegenlaufentwicklungsprinzip, bei welchem zwei Entwicklerwalzen EW zueinander gegensinnig bewegt werden. Es ergibt sich eine abfallende Kennlinie des Tonerangebots TA in der Nähe der Vorderkante 10a sowie der Hinterkante 10b. Im abfallenden Bereich dieser Kennlinien ist der Meßfleck a1 bzw. a1' anzuordnen, im geradlinigen Bereich der Meßort a2.Figure 4 relates to the characteristics of the toner supply TA over the Length of the toner mark 10 in the case of a co-reverse development principle, in which two developer rollers EW to each other be moved in opposite directions. There is a falling Characteristic curve of the toner supply TA near the front edge 10a and the rear edge 10b. In the sloping area this The measuring spot a1 or a1 'is to be arranged in a straight line Area of measurement location a2.

    Figur 5 zeigt den Zusammenhang zwischen Flächendeckung FD an einer Vollfläche, wie beispielsweise einer Tonermarke 10, und dem Tonerangebot TA in der Entwicklerzone. Bei geringem Tonerangebot TA ist auch die Flächendeckung FD gering. Diese Flächendeckung nimmt bis zu 100% zu, wenn das Tonerangebot ansteigt. Eine Flächendeckung von 100% bedeutet, daß die Tonermarke 10 völlig mit Toner bedeckt ist und keine Fehlstelle vorhanden ist, die ein Durchscheinen der Oberfläche der Fotoleitertrommel ermöglicht. Wenn bei einer Flächendeckung von 100% weitere Tonerschichten aufgebaut werden, so wird demzufolge die Schwärzung beim Druck nicht weiter erhöht. Interessanterweise wird nach dem Erreichen einer Flächendeckung FD von 100% und zunehmendem Tonerangebot TA bei vielen Druckern ein Kurvenverlauf gemäß der Kurve 28 festgestellt, wobei die Flächendeckung FD wieder abnimmt. Dies mag auf eine Verklumpung und auf Irregularitäten beim Tonerschichtaufbau zurückzuführen sein, so daß Schichten entstehen, die die komplette Flächendeckung wieder aufheben.Figure 5 shows the relationship between area coverage FD a full area, such as a toner mark 10, and the toner supply TA in the developer zone. With little Toner supply TA, the area coverage FD is low. This Coverage increases up to 100% when the toner supply increases. An area coverage of 100% means that the toner mark 10 is completely covered with toner and no defect is present, which shows through the surface of the photoconductor drum allows. If with an area coverage of Accordingly, 100% more toner layers are built up the blackening in printing does not increase any further. Interestingly, becomes FD after reaching an area coverage of 100% and increasing toner supply TA for many printers a curve shape determined according to curve 28, the Area coverage FD decreases again. This may be due to clumping and attributed to irregularities in the toner layer structure be so that layers are created that complete the Remove area coverage again.

    Figur 6 zeigt die Anordnung der Meßorte a1 und a2 beim Gegenlaufentwicklungsprinzip. Wie erwähnt muß ein Meßort a1 im Bereich der abfallenden Kennlinie angeordnet werden, während der andere Meßort a2 im geradlinigen Bereich der Kennlinie anzuordnen ist. Die Kennlinie 30 zeigt Schnittpunkte mit Kennlinien unterschiedlicher Tonerkonzentration TK, deren zugehörigen Längen L die Meßorte für a2 definieren. Aus praktischen Gründen wird der Meßort a2 rechts der Kurve 30 bei relativ großer Länge L festgelegt.FIG. 6 shows the arrangement of the measuring locations a1 and a2 in the counter-development principle. As mentioned, a measuring location a1 in Area of the falling characteristic curve can be arranged during the other measurement location a2 in the rectilinear area of the characteristic to be ordered. The characteristic curve 30 also shows intersection points Characteristic curves of different toner concentration TK, their the corresponding lengths L define the measuring locations for a2. For practical For reasons, the measurement location a2 becomes to the right of curve 30 at relatively large length L set.

    In der Figur 6 ist ferner zu erkennen, daß für sehr hohe Tonerkonzentrationen TK die Kennlinie für die Flächendeckung FD einen geraden Verlauf hat, d.h. die Kennlinie fällt nicht ab, sondern kann sogar im Anfangsbereich leicht ansteigen, wie dies durch den Abschnitt 32 angedeutet ist. Bei sehr hohen Tonerkonzentrationen ergibt sich also über die Länge einer Vollfläche eine gleichmäßig dichte Flächendeckung von etwa 100%.In Figure 6 it can also be seen that for very high toner concentrations TK the characteristic curve for the area coverage FD has a straight course, i.e. the characteristic does not drop, but can even rise slightly in the beginning, like this is indicated by section 32. At very high Toner concentrations thus result over the length of one Full area a uniformly dense coverage of about 100%.

    Figur 7 zeigt anhand eines praktischen Beispiels den Zusammenhang zwischen Tonerangebot TA und Flächendeckung FD uber die Lange L bei verschiedenen Tonerkonzentrationen TK, wobei die unterste Kennlinie 34 eine niedrige Tonerkonzentration hat. Die Kennlinien 36, 38, 40, 42 zeigen zunehmende Tonerkonzentrationen TK, wobei die Kennlinie 42 eine sehr hohe Tonerkonzentration TK betrifft, beispielsweise von 7 Gewichtsprozent und mehr. Die Tonermarke 10 hat eine typische Länge 1 von 8 bis 16 mm und eine Breite b von 4 bis 10 mm. Es ergeben sich an den Meßorten a1 und a2 Differenzen ΔTA im Tonerangebot, welche mit ansteigender Tonerkonzentration TK abnehmen.FIG. 7 shows the relationship using a practical example between toner offer TA and area coverage FD uber the length L at different toner concentrations TK, where the lowest characteristic 34 is a low toner concentration Has. The characteristic curves 36, 38, 40, 42 show increasing toner concentrations TK, the characteristic 42 being a very high one TK toner concentration affects, for example, 7 percent by weight and more. The toner mark 10 has a typical one Length 1 from 8 to 16 mm and a width b from 4 to 10 mm. It differences ΔTA im result at the measuring locations a1 and a2 Toner supply, which with increasing toner concentration TK lose weight.

    Figur 8 zeigt den Zusammenhang zwischen der durch den Strahlungsempfänger gemessenen Spannung U an den verschiedenen Meßorten a1, a2 für einen schwarzen Toner mit geringem Reflexionsvermögen und einem roten Toner mit relativ hohem Reflexionsvermögen über die Tonerkonzentration TK, die in Gewichtsprozent aufgetragen ist. Die maximale Spannung Um ergibt sich, wenn der Spannungsempfänger die von der blanken Oberfläche der Fotoleitertrommel reflektierte Strahlung mißt. Die Kennlinien für den roten Toner und den schwarzen Toner zeigen die Spannungswerte, wie sie an den Meßorten a1 und a2 gemessen werden. Der vertikal gestrichelte Bereich entspricht der jeweiligen Spannungsdifferenz ΔU. Sie ist abhängig vom Reflexionsvermögen des jeweiligen Toners. Die Beziehung für ΔU ist rechts oben im Diagramm wiedergegeben, worin RT das Reflexionsvermögen des jeweiligen Toners, RFLT das Reflexionsvermögen der Oberfläche der Fotoleitertrommel und K eine geräteseitige Konstante für einen vorbestimmten Flächendeckungsgrad, z.B. nahe 100%, ist.FIG. 8 shows the relationship between the voltage U measured by the radiation receiver at the various measuring locations a1, a2 for a black toner with low reflectivity and a red toner with relatively high reflectivity via the toner concentration TK, which is plotted in percent by weight. The maximum voltage Um is obtained when the voltage receiver measures the radiation reflected from the bare surface of the photoconductor drum. The characteristic curves for the red toner and the black toner show the voltage values as measured at the measuring locations a1 and a2. The vertical dashed area corresponds to the respective voltage difference ΔU. It depends on the reflectivity of the respective toner. The relationship for ΔU is shown at the top right of the diagram, in which R T is the reflectivity of the respective toner, R FLT is the reflectivity of the surface of the photoconductor drum and K is a device-side constant for a predetermined area coverage, for example close to 100%.

    Das Reflexionsverhältnis RT/RFLT kann für jede Tonerfarbe und für jede Fotoleitertrommel ermittelt und dann bei einer Auswertung berücksichtigt werden, beispielsweise in Form einer Korrekturtabelle. Die jeweilige Spannungsdifferenz ΔU kann dann korrigiert werden, um unterschiedliche Tonertypen zu berücksichtigen. In der Praxis hat es sich gezeigt, daß der Quotient aus RT/RFLT sehr klein ist, da das Reflexionsvermogen des jeweiligen Toners gegenüber dem Reflexionsvermögen der Oberfläche der Fotoleitertrommel zu vernachlässigen ist. Beispielsweise ist der Wert RT/RFLT etwa 1/300 für schwarzen Toner und 1/10 für stark reflektierenden Toner, wie z.B. gelben oder roten Toner. Der sich aus den unterschiedlichen Reflexionsvermögen verschiedener Tonerfarben ergebende Fehler ist daher relativ klein.The reflection ratio R T / R FLT can be determined for each toner color and for each photoconductor drum and can then be taken into account in an evaluation, for example in the form of a correction table. The respective voltage difference ΔU can then be corrected to take into account different toner types. In practice, it has been shown that the ratio of R T / R FLT is very small, since the reflectivity of the respective toner is negligible compared to the reflectivity of the surface of the photoconductor drum. For example, the value R T / R FLT about 1/300 for black toner, and 1/10 is highly reflective toner such as yellow or red toner. The error resulting from the different reflectivities of different toner colors is therefore relatively small.

    Aus der Figur 8 wird deutlich, daß für zunehmende Tonerkonzentration TK die Spannungsdifferenz ΔU gegen Null geht. Es ergibt sich ein praktischer Regelbereich RB von ca. 2,3 bis 6,6 Gewichtsprozent Toner. Rechts der Linie 44 liegt Übertonerung vor, wobei sich die Spannungsdifferenz ΔU umkehrt. Dieser Bereich der Übertonerung wird vermieden, wenn der Regelvorgang links von der Linie 44 begonnen und bis zu einem Sollwert geführt wird, der geringfügig größer als Null ist.It is clear from FIG. 8 that for increasing toner concentration TK the voltage difference ΔU goes to zero. It there is a practical control range RB of approx. 2.3 to 6.6 weight percent toner. Overtoning is to the right of line 44 before, the voltage difference ΔU being reversed. This area of over-toning is avoided when the control process started on the left of line 44 and up to one Setpoint is guided, which is slightly greater than zero.

    Figur 9 zeigt eine Gegenüberstellung des Reflexionsvermögens unterschiedlicher Tonerarten, wie sie die Kennlinie 46 ausdrückt, wobei eine Flächendeckung FD nahe 100% angenommen wird. Im darunterliegenden Diagramm der Figur 9 ist das Ergebnis einer Regelung unter Berücksichtigung der Spannungsdifferenz ΔU aufgezeigt. Als Sollwert wird ein Wert vorgegeben, bei dem die Flächendeckung FD nahe 100% sein soll. Unabhängig vom absoluten Reflexionsvermögen und den Absolutwerten der vom Strahlungssensor erzeugten Spannung U ergibt sich für verschiedenfarbige Toner ein relativ konstanter Wert der Flächendeckung FD. Die Kennlinie der Tonerkonzentration TK dagegen schwankt für die unterschiedlichen Tonerfarben.Figure 9 shows a comparison of the reflectivity different types of toner, as expressed by the characteristic curve 46, assuming an area coverage FD close to 100% becomes. The result is shown in the diagram below in FIG. 9 control taking into account the voltage difference ΔU shown. A value is specified as the setpoint, where the area coverage FD should be close to 100%. Independently of the absolute reflectivity and the absolute values the voltage U generated by the radiation sensor results for different colored toners a relatively constant value of the area coverage FD. The characteristic of the toner concentration TK, however fluctuates for the different toner colors.

    Figur 10 zeigt den schematischen Aufbau einer Druckeinrichtung, bei der die Erfindung realisiert ist. Eine Fotoleitertrommel FLT dreht sich beim Druckvorgang in Richtung des Pfeiles P1, wobei auf Einzelblätter 50 ein Tonerbild aufgedruckt wird. Eine Entwicklerstation 52 enthält einen behalter 54, in welchem das Entwicklergemisch aus Toner in Trager aufbereitet wird. Eine Entwicklerwalze 56 überträgt den Toner auf die Oberfläche der Fotoleitertrommel FLT. Die Fotoleitertrommel FLT und die Entwicklerstation 52 arbeiten nach dem Gegenlaufentwicklungsprinzip, d.h. die Drehrichtungen der Entwicklerwalze 56 und der Fotoleitertrommel FLT sind einander entgegengesetzt. Zur Entwicklerstation 52 gehört auch eine Tonerfördervorrichtung 58, welche aus einem Vorratsbehälter Toner einer Tonerquerzuförderung 60 dosiert zuführt. Diese Tonerquerzuförderung 60 gibt den Toner an den Behälter 54 ab. Die Tonerfördervorrichtung 58 enthält einen Antriebsmotor, der durch einen Zweipunktregler 62 in den Betriebszustand EIN oder AUS geschaltet wird.FIG. 10 shows the schematic structure of a printing device, in which the invention is implemented. A photoconductor drum FLT turns towards the Arrow P1, wherein a toner image is printed on single sheets 50 becomes. A developer station 52 contains a container 54, in which the developer mixture of toner in carrier is processed. A developer roller 56 transfers the toner on the surface of the FLT photoconductor drum. The photoconductor drum FLT and developer station 52 operate on the Counter-development principle, i.e. the directions of rotation of the The developer roller 56 and the photoconductor drum FLT are each other opposed. Also belongs to the developer station 52 a toner conveying device 58 which comes from a reservoir Toner a toner cross feed 60 doses. This toner cross feed 60 delivers the toner to the container 54 from. The toner delivery device 58 includes a drive motor, by a two-point controller 62 in the operating state Is switched ON or OFF.

    Auf der Fotoleitertrommel FLT ist eine Tonermarke 10 vorgesehen, die mit Hilfe eines Reflexsensors 64 abgetastet wird. Dieser Reflexsensor 64 enthält eine LED 66, die monochromatische Infrarotstrahlung aussendet. Die Verwendung von Infrarotstrahlung hat den Vorteil, das diese Strahlung weniger sensibel auf die unterschiedlichen Tonerfarben reagiert, so daß deren Reflexionsvermogen weniger stark in das Ergebnis eingeht. Außerdem kann durch Verwendung der Infrarotstrahlung weißes Störlicht besser unterdrückt werden. Die LED 66 wird aus einer steuerbaren Stromquelle 68 mit dem Strom IL gespeist. Zwischen der Fotoleitertrommel FLT und dem Reflexsensor 64 ist eine Glasabdeckung 72 angeordnet, die das Verschmutzen durch Tonerpartikel verhindert. Das ausgesandte Strahlenbündel 74 wird unterschiedlich reflektiert. Die reflektierte Strahlung setzt sich zusammen aus einen Anteil 76, der von der Oberfläche der Fotoleitertrommel FLT herrührt. Ein weiterer Strahlungsanteil 78 ergibt sich aufgrund der Reflexion an der Glasabdeckung 72. Schließlich ergibt sich noch ein Strahlungsanteil 80, der von der Reflexion an den Tonerteilchen herrührt. Die von der Tonermarke 10 insgesamt reflektierte Strahlung wird von einer Empfangseinrichtung 82 detektiert, die eine Empfangsdiode enthält. Die Empfangereinrichtung 82 bildet den Wert ΔV=Ua2-Ua1. A toner mark 10 is provided on the photoconductor drum FLT and is scanned with the aid of a reflex sensor 64. This reflex sensor 64 contains an LED 66 which emits monochromatic infrared radiation. The use of infrared radiation has the advantage that this radiation reacts less sensitively to the different toner colors, so that their reflectivity is less important in the result. In addition, white interference light can be suppressed better by using infrared radiation. The LED 66 is supplied with the current I L from a controllable current source 68. A glass cover 72 is arranged between the photoconductor drum FLT and the reflex sensor 64, which prevents contamination by toner particles. The emitted beam 74 is reflected differently. The reflected radiation is composed of a portion 76 that originates from the surface of the photoconductor drum FLT. A further radiation component 78 results due to the reflection on the glass cover 72. Finally, there is also a radiation component 80 which results from the reflection on the toner particles. The radiation reflected overall by the toner mark 10 is detected by a receiving device 82 which contains a receiving diode. The receiver device 82 forms the value ΔV = Ua2-Ua1.

    Der Wert ΔU wird mit einem Sollwert Us am Regler 62 verglichen. Wenn ΔU größer als Us ist, so wird die Tonerfördervorrichtung 58 in den EIN-Zustand geschaltet und solange Toner nachgefördert, bis die Abweichung zwischen ΔU und Us auf annähernd Null geregelt ist.The value ΔU is compared with a setpoint Us on the controller 62. If ΔU is larger than Us, the toner delivery device becomes 58 switched to the ON state and as long as toner promoted until the deviation between ΔU and Us approaches Is regulated zero.

    Während einer Einstellphase wird der Schalter 84 in Richtung des Pfeiles 86 geschaltet, wodurch die steuerbare Stromquelle 68 über den Regler 62 angesteuert wird. In dieser Einstellphase wird eine Normierung auf das Reflexionsvermögen der blanken Oberfläche der Fotoleitertrommel FLT vorgenommen. Hierbei wird die blanke Oberfläche der Fotoleitertrommel FLT durch den Reflexsensor 64 angestrahlt und in der Empfangseinrichtung 82 der zugehörige Spannungswert U gemessen. Die steuerbare Stromquelle 68 wird nun so eingestellt, daß sich in der Empfangseinrichtung 82 ein konstanter Maximalwert Um einstellt. Mit dieser Einstellung wird dann später die Tonermarke 10 abgetastet. Durch diese Vorgehensweise wird erreicht, daß das Reflexionsvermögen der Oberfläche der Fotoleitertrommel weniger stark ins Ergebnis eingeht, denn das unterschiedliche Reflexionsverhalten wird auf den Wert Um normiert. Die Werte ΔU unterschiedlicher Fotoleitertrommel sind somit bei ansonsten gleicher Tonerabtastung weitgehend konstant. Bei Austausch der Fotoleitertrommel FLT gegen eine andere ändert sich also an der Regelung der Tonerkonzentration nichts. Die beschriebene Einstellphase kann auch in Zeitabständen wiederholt werden, um eine Änderung im Reflexionsvermögen der Oberfläche der Fotoleitertrommel FLT zu korrigieren.During an adjustment phase, switch 84 turns towards of arrow 86 switched, which makes the controllable power source 68 is controlled via the controller 62. In this adjustment phase a standardization on the reflectivity of the bare surface of the FLT photoconductor drum. Here, the bare surface of the photoconductor drum FLT illuminated by the reflex sensor 64 and in the receiving device 82 the associated voltage value U is measured. The controllable current source 68 is now set so that a constant maximum value Um in the receiving device 82 established. With this setting, the toner mark will later become 10 scanned. By doing this, that the reflectivity of the surface of the photoconductor drum less important in the result because that different reflection behavior is based on the value Um normalized. The values ΔU of different photoconductor drums are thus largely the same with otherwise identical toner scanning constant. When exchanging the FLT photoconductor drum for one others therefore change in the regulation of the toner concentration Nothing. The adjustment phase described can also be done at intervals be repeated for a change in reflectivity to correct the surface of the FLT photoconductor drum.

    Ein quer zur Rotationsrichtung P1 der Fotoleitertrommel FLT vor der Entwicklerstation 52 angeordneter Zeichengenerator (nicht dargestellt) schreibt das latente Bild oder die latenten Bilder für eine Tonermarke 10 oder mehrere Tonermarken auf die Oberfläche der Fotoleitertrommel FLT. Der Zeilengenerator und auch der Reflexsensor 64 sind im allgemeinen lösbar eingebaut, wobei sich Einbautoleranzen ergeben. Diese können sich so summieren, daß der Abstand längs des Umfangs der Fotoleitertrommel FLT zwischen Zeichengenerator und Reflexsensor 64 typischerweise bis zu 2 mm schwankt. Üblicherweise wird zum Abtasten der Tonermarken 10 eine Zeitsteuerung verwendet. Mit dem Start des Schreibens des latenten Bildes durch den Zeichengenerator wird ein Startzeitpunkt festgelegt. Aufgrund der konstanten Drehgeschwindigkeit der Fotoleitertrommel FLT und des an sich bekannten Abstandes zwischen Zeilengenerator und Reflexsensor 64 wird eine Verzögerungszeit tm ermittelt, aus der sich der Abtastzeitpunkt für die Tonermarke 10 durch den Reflexsensor 64 ergibt.A transverse to the direction of rotation P1 of the photoconductor drum FLT Character generator arranged in front of the developer station 52 (not shown) writes the latent image or latent ones Images for a toner brand 10 or more toner brands on the surface of the FLT photoconductor drum. The line generator and also the reflex sensor 64 are generally detachable installed, whereby installation tolerances result. these can add up so that the distance along the circumference of the photoconductor drum FLT between character generator and reflex sensor 64 typically fluctuates up to 2 mm. Usually a timer is used to scan the toner marks 10. With the start of writing the latent image a start time is determined by the character generator. Due to the constant rotation speed of the photoconductor drum FLT and the known distance between Line generator and reflex sensor 64 becomes a delay time tm determined from which the sampling time for the toner mark 10 results from the reflex sensor 64.

    Figur 11 zeigt den Spannungsverlauf U beim Vorbeilauf der Tonermarke 10 am Reflexsensor 64. Der Verlauf entspricht dem nach Figur 1. Das Abtasten der Tonermarke 10 erfolgt innerhalb eines Zeitrahmens ZR zu Zeitpunkten T1 bis T16. Zu jedem Rasterzeitpunkt T1 bis T16 werden vier Abtastwerte gewonnen, die als Digitalwerte einer Computersteuerung zugeführt werden. Als gemittelter Abtastwert wird dann der Mittelwert der zu jedem Zeitpunkt T1 bis T16 ermittelten 16 Abtastwerte verwendet. Die gemittelten Abtastwerte werden in einem Speicher zwischengespeichert.FIG. 11 shows the voltage curve U as the toner mark passes 10 on the reflex sensor 64. The course corresponds to that according to Figure 1. The scanning of the toner mark 10 takes place within a time frame ZR at times T1 to T16. To each Raster times T1 to T16, four samples are obtained, which are fed as digital values to a computer control. The mean value of the 16 samples determined at each time T1 to T16 are used. The averaged samples are stored in a memory cached.

    Der Zeitrahmen ZR beginnt zum Rasterzeitpunkt T1 nach Ablauf der Verzögerungszeit tm. Bei dem weiter oben beschriebenen Verfahren werden als Meßwerte, aus denen dann die Differenz bzw. der Quotient ermittelt werden, gemittelte Abtastwerte zu den Zeitpunkten T4 bis T7 und T10 bis T13 gewonnen. Die gemittelten Abtastwerte zu den Zeitpunkten T4 bis T7 und T10 bis T13 werden wiederum gemittelt, um den erheblichen Störanteil in den Signalen durch Mittelwertbildung auszufiltern. Die so gewonnenen Werte zu den Meßorten a1 und a2 werden dann weiterverarbeitet. The time frame ZR begins at the raster time T1 after expiry the delay time tm. In the case described above Methods are called measured values, from which the difference is then or the quotient are determined, averaged samples won the times T4 to T7 and T10 to T13. The averaged Samples at times T4 to T7 and T10 up to T13 are again averaged to account for the significant amount of interference to be filtered out in the signals by averaging. The values obtained in this way for the measuring locations a1 and a2 are then further processed.

    Wie erwähnt wird als Referenzpunkt zum Erkennen der Lage der Tonermarke 10 die Vorderkante 10a oder die Hinterkante 10b der Tonermarke 10 verwendet. Wenn der Strahlfleck des Reflexsensors 64 hälftig auf diese Vorderkante 10a bzw. Hinterkante 10b trifft, so beträgt die Spannung Uh zumindest annähernd Uh = (Uref - Utm) / 2, worin Uref die Spannung bei Reflexion der Strahlung an der blanken Fotoleitertrommel FLT und Utm die Spannung bei Reflexion an der Tonermarke 10 zu den Zeitpunkten T10 bis T13 ist.As mentioned, the front edge 10a or the rear edge 10b of the toner mark 10 is used as a reference point for recognizing the position of the toner mark 10. If the beam spot of the reflex sensor 64 strikes half of this front edge 10a or rear edge 10b, the voltage Uh is at least approximately Uh = (Uref - Utm) / 2, where Uref is the voltage upon reflection of the radiation on the bare photoconductor drum FLT and Utm is the voltage upon reflection at the toner mark 10 at times T10 to T13.

    Um den zur Spannung Uh gehörenden Zeitpunkt Tref entweder an der Vorderkante 10a oder an der Hinterkante 10b der Tonermarke 10 zu ermitteln, wird der Zeitrahmen ZR bezüglich der Verzögerungszeit tm verschoben und jeweils zum Zeitpunkt T1 die Spannung U abgestastet. Dieses Verschieben erfolgt iterativ je Tonermarke um einen Zeitabstand zwischen den Zeitpunkten T1 und T2. Die Anzahl der Verschiebeschritte, die erforderlich sind, um die Spannung Uh zu ermitteln, gibt dann an, um wieviel die Verzögerungszeit tm zu korrigieren ist, um die Tonermarke 10 an den Meßorten a1, a2 abzutasten, deren Lage eine definierte Entfernung zur Vorderkante 10a bzw. zur Hinterkante 10b der Tonermarke 10 haben. Das Abtasten zum Zeitpunkt T1 wird deshalb gewählt, weil sich aufgrund von Interruptlaufzeiten der interruptgesteuerten Erzeugung der Zeitpunkte T1 bis T16 spätere Zeitpunkte zeitlich variieren können. Auch hier ist darauf hinzuweisen, daß in Figur 11 der Spannungsverlauf U in einem vertikal gestauchten Zustand wiedergegeben ist; die Spannung Uref ist wesentlich höher in bezug auf die Spannung Utm als in dem Verlauf wiedergegeben.At the time Tref belonging to the voltage Uh either on the leading edge 10a or the trailing edge 10b of the toner mark 10, the time frame ZR with respect to the Delay time tm shifted and each time T1 the voltage U sampled. This shifting is done iteratively per toner mark by a time interval between the times T1 and T2. The number of move steps required are to determine the voltage Uh, then indicates by how much the delay time tm has to be corrected by the To scan toner mark 10 at the measuring locations a1, a2, their position a defined distance to the front edge 10a or to the rear edge 10b of the toner mark 10. Sampling at the time T1 is chosen because of interrupt runtimes the interrupt-controlled generation of the times T1 to T16 later times can vary in time. It should also be pointed out here that in FIG Voltage curve U reproduced in a vertically compressed state is; the voltage Uref is much higher in with respect to the voltage Utm as reproduced in the course.

    Figur 12 zeigt den Zustand, um dem der Zeitrahmen ZR so weit verschoben worden ist, bis zum Zeitpunkt T1 die Spannung Uh zu ermitteln. Die Anzahl der zum Auffinden der Spannung Uh erforderlichen Verschiebetakte ist ein Maß dafür, um wieviel die Verzögerungszeit tm zu korrigieren ist, um die Tonermarke 10 bzw die Tonermarken an den vorbestimmten Meßorten a1, a2 abzutasten.Figure 12 shows the state around which the time frame ZR so far has been shifted until the time T1 the voltage Uh to investigate. The number of times to find the voltage Uh required shift clocks is a measure of how much the delay time tm is to correct the toner mark 10 or the toner marks at the predetermined measuring locations a1, a2 scan.

    Das beschriebene Verfahren zum Festlegen der genauen Lage der Tonermarke 10 wird bei jeder Ersteinstellung des Druckers oder des Kopierers angewandt. Bei diesem Einstellen wird eine Vielzahl von Tonermarken auf die Fotoleitertrommel FLT gedruckt, um eine hohe Präzision bei der Einstellung zu erzielen. Die genannten Verfahrensschritte können auch in vorgegebenen Zeitabständen, z.B. in Abständen von einer Stunde Betriebszeit, oder nach jedem erneuten Einschalten des Druckers oder Kopierers (set up) angewandt werden.The procedure described for determining the exact location of the Toner mark 10 will appear every time the printer is first set up or the copier applied. With this setting, a Large number of toner marks printed on the FLT photoconductor drum, to achieve a high precision in the setting. The method steps mentioned can also be specified in predetermined Intervals, e.g. at intervals of one hour of operation, or each time the printer is turned on or copier (set up) can be used.

    Das gezeigte Ausführungsbeispiel läßt sich im Rahmen der Erfindung abändern. Z.B. kann der Sensor 64 die Tonermarke 10 nach dem Umdrucken auf ein Trägermaterial, beispielsweise Papier, abtasten. In diesem Fall wird dann auf das Reflexionsvermögen des Trägermaterials normiert. Bei einer anderen Variante kann anstelle einer Fotoleitertrommel ein Fotoleiterband verwendet werden. Als Toner kann schwarzes Tonermaterial, farbiges Tonermaterial, ein aus Tonermaterialien mit verschiedenen Grundfarben zusammengemischter Toner oder ein transparentes Tonermaterial verwendet werden. Diese Variante ist beispielsweise in der WO98/39691 A1 beschrieben. The embodiment shown can be within the scope of the invention amend. For example, can the sensor 64 the toner mark 10 after transfer printing onto a carrier material, for example Paper, palpate. In this case, then the reflectivity of the carrier material standardized. Another one Variant can instead of a photoconductor drum a photoconductor tape be used. Black toner material, colored toner material, one made of toner materials with different basic colors mixed toner or a transparent toner material can be used. This variant is described for example in WO98 / 39691 A1.

    BezugszeichenlisteLIST OF REFERENCE NUMBERS

    1010
    Tonermarketoner mark
    10a10a
    Vorderkante der TonermarkeFront edge of the toner mark
    10b10b
    Hinterkante der TonermarkeTrailing edge of the toner mark
    12-2412-24
    Abschnitte der Kennlinie der Sensorspannung über die Länge L der TonermarkeSections of the characteristic curve of the sensor voltage the length L of the toner mark
    2626
    SättigungskennlinieSaturation characteristic
    2828
    Kurvenabschnittcurve section
    3030
    Kennliniecurve
    3232
    KennlinienabschnittCharacteristic section
    34-4234-42
    Kennlinien der TonerkonzentrationCharacteristic curves of the toner concentration
    4444
    Grenzlinieboundary line
    5050
    EinzelblätterSingle sheets
    5252
    Entwicklerstationdeveloper station
    5454
    Behältercontainer
    5656
    Entwicklerwalzedeveloper roller
    5858
    TonerfördervorrichtungToner conveyor
    6060
    TonerquerzuförderungTonerquerzuförderung
    6262
    ZweipunktreglerTwo-point controller
    6464
    Reflexsensorreflex sensor
    6666
    LEDLED
    6868
    steuerbare Stromquellecontrollable power source
    7272
    Glasabdeckungglass cover
    7474
    Strahlenbündelray beam
    76,78,8076,78,80
    Strahlungsanteileradiation components
    8282
    Empfängereinrichtungreceiver device
    8484
    Schalterswitch
    8686
    Pfeil P1 PfeilArrow P1 arrow
    a1,a2a1, a2
    Meßortemeasurement sites
    UU
    Spannungtension
    LL
    Länge der TonermarkeLength of the toner mark
    UmAround
    maximaler Spannungswertmaximum voltage value
    vv
    Geschwindigkeit speed
    ΔU.DELTA.U
    Differenzwert der SpannungDifferential value of the voltage
    TATA
    Tonerangebottoner supply
    EWEW
    Entwicklerwalzedeveloper roller
    FLTFLT
    FotoleitertrommelPhotoconductor drum
    TKTK
    Tonerkonzentrationtoner concentration
    FDFD
    Flächendeckungcoverage
    ΔTA.DELTA.Ta
    Differenz im TonerangebotDifference in toner supply
    RT R T
    Reflexionsvermögen des TonersReflectivity of the toner
    RFLT R FLT
    Reflexionsvermögen der FotoleitertrommelReflectivity of the photoconductor drum
    ZRZR
    Zeitrahmentimeframe
    TrefTref
    ReferenzzeitpunktReference time
    UhUh
    Spannung zum Referenz-ZeitpunktVoltage at the reference time
    UtmUtm
    Spannung bei Reflexion an der TonermarkeTension upon reflection at the toner mark
    T1 - T16T1 - T16
    Meßzeitpunktemeasuring times

    Claims (35)

    1. Device for electrographic printing or copying, comprising
      a toner carrier (FLT), on which a latent image is generated,
      a developer station (52) for inking the latent image with toner, said developer station containing a developer mixture of toner and carrier with an adjustable proportion of toner,
      wherein on the toner carrier (FLT) at least one toner mark (10) is inked with toner for monitoring and adjusting the toner surface coverage (FD),
      the toner mark (10) provided with toner is scanned by at least one sensor (64) at at least two measurement locations (a1, a2) that are arranged successively as seen in a direction of motion of the toner carrier (FLT), and electrical signals (U) are formed from the respective surface coverage (FD) at said measurement locations (a1, a2),
      a toner supply (TA) over the length of the toner mark (10) falls or rises in one section and is constant in another section,
      at least one of the measurement locations (a1, a2) is located in the section with falling or rising toner supply (TA),
      and wherein the proportion of toner in the developer mixture is adjusted dependent on the difference (ΔU) or the quotient of the absolute values of the signals at these two measurement locations.
    2. Device according to claim 1, characterized in that the sensor (64) scans the toner mark provided with toner on the toner carrier (FLT) and/or on a carrier material.
    3. Device according to claim 1 or 2, characterized in that the difference (ΔU) or the quotient is compared to a desired value (Us), and that, dependent on the comparison, a controller (62) actuates a transport mechanism (58) which feeds toner to the developer station (52).
    4. Device according to claim 3, characterized in that the controller (62) is a two-position controller.
    5. Device according to claim 3 or 4, characterized in that a fraction of the value of the signal (Um) is prescribed as desired value (Us), which signal is generated given reflection at the surface of the toner carrier (FLT) or of the carrier material, preferably 1/300 to 1/10.
    6. Device according to one of the preceding claims, characterized in that a first measurement location (a1) is located within the first third of the length of the toner mark (10) as seen in the direction of motion of the toner carrier (FLT).
    7. Device according to one of the preceding claims, characterized in that a second measurement location (a2) is located within the last third of the length of the toner mark (10) as seen in the direction of motion of the toner carrier (FLT).
    8. Device according to one of the preceding claims, characterized in that the toner mark is scanned using a reflex sensor (64).
    9. Device according to one of the preceding claims, characterized in that the reflex sensor (64) emits monochromatic infrared radiation.
    10. Device according to one of the preceding claims, characterized in that the toner mark is scanned using a capacitive sensor.
    11. Device according to one of the preceding claims, characterized in that the signals over several toner marks are averaged and that an average difference of the averaged signals is used as difference.
    12. Device according to one of the preceding claims, characterized in that black toner, coloured toner, a toner that is mixed together from toner materials with primary colours, or a transparent toner is used as toner.
    13. Method for electrographic printing or copying,
      in which a latent image is generated on a toner carrier (FLT),
      a developer station (52) inks the latent image with toner, said developer station (52) containing a developer mixture of toner and carrier with an adjustable proportion of toner,
      at least one toner mark (10) on the toner carrier (FLT) is inked with toner for monitoring and adjusting the toner surface coverage (FD),
      the toner mark (10) provided with toner is scanned by at least one sensor (64) at at least two measurement locations (a1, a2) that are arranged successively as seen in the direction of motion of the toner carrier (FLT), and electrical signals (U) are formed from the respective surface coverage (FD) at these measurement locations (a1, a2),
      a toner supply (TA) over the length of the toner mark (10) falls or rises in one section and is constant in another section,
      at least one of the measurement locations (a1, a2) is located in the section with falling or rising toner supply (TA),
      and wherein the proportion of toner in the developer mixture is adjusted dependent on the difference (ΔU) or the quotient of the absolute values of the signals at these two measurement locations.
    14. Method according to claim 13, characterized in that the sensor (64) scans the toner mark (10) provided with toner on the toner carrier (FLT) and/or on a carrier material.
    15. Method according to claim 13 or 14, characterized in that the difference (ΔU) or the quotient is compared to a desired value (Us), and that, dependent on the comparison, a controller (62) actuates a transport mechanism (58) which feeds toner to the developer station (52).
    16. Method according to claim 15, characterized in that the controller (62) is a two-position controller.
    17. Method according to one of the preceding claims, characterized in that a first measurement location (a1) is located within the first third of the length of the toner mark (10) as seen in the direction of motion of the toner carrier (FLT).
    18. Method according to one of the preceding claims, characterized in that a second measurement location (a2) is located within the last third of the length of the toner mark (10) as seen in the direction of motion of the toner carrier (FLT).
    19. Method according to one of the preceding claims, characterized in that the toner mark is scanned using a reflex sensor (64).
    20. Method according to one of the preceding claims, characterized in that the signals over several toner marks are averaged and that an average difference of the averaged signals or an average quotient of the averaged signals is used as difference.
    21. Method according to one of the preceding claims, characterized in that black toner, coloured toner, a toner that is mixed together from toner materials with primary colours, or a transparent toner is used as toner.
    22. Device for electrographic printing or copying, comprising
      a toner carrier (FLT), on which a latent image is generated,
      a developer station (52) for inking the latent image with toner, said developer station (52) containing a developer mixture of toner and carrier,
      wherein on the toner carrier (FLT) at least one toner mark (10) is inked with toner for monitoring and adjusting the toner surface coverage,
      the toner mark (10) provided with toner is scanned by at least one sensor (64) at at least two measurement locations (a1, a2) that are arranged successively as seen in the direction of motion of the toner carrier (FLT), and electrical signals (U) are formed from the respective surface coverage (FD) at these measurement locations (a1, a2), which signals are processed by a control device,
      a toner supply (TA) over the length of the toner mark (10) falls or rises in one section and is constant in another section,
      at least one of the measurement locations (a1, a2) is located in the section with falling or rising toner supply (TA),
      a reference time (Tref) is defined, at which a reference point (10a, 10b) on the toner mark (10) passes a stationary scanning sensor (64),
      and wherein the scanning at the two measurement locations (a1, a2) occurs relative to this reference time (Tref).
    23. Device according to claim 22, characterized in that the front edge (10a) or the back edge (10b) of the toner mark is used as reference point on said toner mark (10).
    24. Device according to claim 22 or 23, characterized in that the sensor (64) which scans the toner mark (10) at the two measurement locations (a1, a2) is provided as scanning sensor.
    25. Device according to one of the preceding claims, characterized in that the scanning at the two measurement locations (a1, a2) occurs after a predetermined delay time (tm), which passes after the time at which the writing of the toner mark (10) occurs.
    26. Device according to claim 25, characterized in that the delay time (tm) is varied dependent on the reference time (Tref).
    27. Device according to one of the preceding claims, characterized in that the reference time (Tref) is fixed when the electrical signal (Uh) of the scanning sensor (64) is approximately equal to the relation Uh = (Uref - Utm) / 2, wherein Uref is the voltage given reflection of the radiation at the blank photoconductive drum (FLT) and Utm is the voltage given reflection at the toner mark (10).
    28. Device according to one of the preceding claims, characterized in that the reflex sensor (64) emits monochromatic infrared radiation.
    29. Device according to one of the preceding claims, characterized in that several scan values are acquired at each measurement location (a1, a2), and an average value is formed from these scan values, which average value is processed.
    30. Method for electrographic printing or copying,
      in which a latent image is generated on the toner carrier (FLT),
      the latent image is inked with toner in a developer station (52), the developer station (52) containing a developer mixture of toner and carrier,
      wherein at least one toner mark (10) on the toner carrier (FLT) is inked with toner for monitoring and adjusting the toner surface coverage,
      the toner mark (10) provided with toner is scanned by at least one sensor (64) at at least two measurement locations (a1, a2) that are arranged successively as seen in the direction of motion of the toner carrier (FLT), and electrical signals (U) are formed from the respective surface coverage (FD) at these measurement locations (a1, a2), which signals are processed by a control device,
      a toner supply (TA) over the length of the toner mark (10) falls or rises in one section and is constant in another section,
      at least one of the measurement locations (a1, a2) is located in the section with falling or rising toner supply (TA),
      a reference time (Tref) is defined, at which a reference point (10a, 10b) on the toner mark (10) passes a stationary scanning sensor (64),
      and wherein the scanning at the two measurement locations (a1, a2) occurs relative to this reference time (Tref).
    31. Method according to claim 30, characterized in that the front edge (10a) or the back edge (10b) of the toner mark (10) is used as reference point on said toner mark (10).
    32. Method according to claim 30 or 31, characterized in that the sensor (64) which scans the toner mark (10) at the two measurement locations (a1, a2) is used as scanning sensor.
    33. Method according to one of the preceding claims, characterized in that the scanning at the two measurement locations (a1, a2) occurs after a predetermined delay time (tm), which passes after the time at which the writing of the toner mark (10) occurs.
    34. Method according to claim 33, characterized in that the delay time (tm) is varied dependent on the reference time (Tref).
    35. Method according to one of the preceding claims, characterized in that the reference time (Tref) is fixed when the electrical signal (Uh) of the scanning sensor (64) is approximately equal to the relation Uh = (Uref - Utm) / 2, wherein Uref is the voltage given reflection of the radiation at the blank photoconductive drum (FLT) or at a carrier material, when the toner mark is scanned on the carrier material, and Utm is the voltage given reflection at the toner mark (10).
    EP99904782A 1998-01-16 1999-01-15 Printing and photocopying device and method whereby one toner mark is scanned at at least two points of measurement Expired - Lifetime EP1047980B1 (en)

    Applications Claiming Priority (5)

    Application Number Priority Date Filing Date Title
    DE19801521 1998-01-16
    DE19801521 1998-01-16
    DE19821922 1998-05-15
    DE19821922 1998-05-15
    PCT/EP1999/000211 WO1999036834A1 (en) 1998-01-16 1999-01-15 Printing and photocopying device and method whereby one toner mark is scanned at at least two points of measurement

    Publications (2)

    Publication Number Publication Date
    EP1047980A1 EP1047980A1 (en) 2000-11-02
    EP1047980B1 true EP1047980B1 (en) 2002-04-10

    Family

    ID=26043151

    Family Applications (1)

    Application Number Title Priority Date Filing Date
    EP99904782A Expired - Lifetime EP1047980B1 (en) 1998-01-16 1999-01-15 Printing and photocopying device and method whereby one toner mark is scanned at at least two points of measurement

    Country Status (6)

    Country Link
    US (1) US6434346B1 (en)
    EP (1) EP1047980B1 (en)
    JP (1) JP2002509291A (en)
    CA (1) CA2316162C (en)
    DE (1) DE59901179D1 (en)
    WO (1) WO1999036834A1 (en)

    Families Citing this family (12)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    EP1254559A2 (en) * 2000-02-04 2002-11-06 Océ Printing Systems GmbH Method and device for control of toner concentration in an electrographic process
    DE10136259A1 (en) * 2001-07-25 2003-02-20 Oce Printing Systems Gmbh Method for controlling a printing process in a printer or copier uses a character generator to produce a toner mark on an intermediate carrier and a reflection sensor to determine color density for a colored toner mark
    US6684035B2 (en) * 2002-06-19 2004-01-27 Nexpress Solutions Llc Adjustable automatic process control density patch location detection
    DE10234711A1 (en) 2002-07-30 2004-02-12 OCé PRINTING SYSTEMS GMBH Method and device for minimizing unwanted toner transfer in a transfer printing station of an electrographic printing device
    DE10246736A1 (en) 2002-10-07 2004-04-22 OCé PRINTING SYSTEMS GMBH Toner feed adjustment method for electrographic printer or copier with toner feed increased to maintain minimal toner feed to developer station
    DE10246733B4 (en) * 2002-10-07 2004-09-30 OCé PRINTING SYSTEMS GMBH Process for instantaneous implementation of a change in the setting of printing parameters on the printed image in an electrographic printing or copying device
    DE10246737A1 (en) * 2002-10-07 2004-01-15 OCé PRINTING SYSTEMS GMBH Method of generating developer in the developing station of an electrophotographic printer or copier where toner is added and its concentration measured until the desired concentration is reached
    US20040196282A1 (en) * 2003-02-14 2004-10-07 Oh Byong Mok Modeling and editing image panoramas
    CN100394322C (en) * 2004-03-02 2008-06-11 精工爱普生株式会社 Toner quantity measuring device, method of measuring toner quantity and image forming apparatus
    DE102006058579A1 (en) 2006-12-12 2008-06-26 OCé PRINTING SYSTEMS GMBH A method and apparatus for processing a measurement signal to detect a property of a toner mark
    JP4710964B2 (en) * 2008-11-28 2011-06-29 ブラザー工業株式会社 Image forming apparatus
    JP5822037B1 (en) * 2015-02-20 2015-11-24 富士ゼロックス株式会社 Image forming apparatus

    Family Cites Families (6)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    JPH07120096B2 (en) * 1986-08-11 1995-12-20 株式会社リコー Image density control device for recording device
    JPS63254476A (en) * 1987-04-11 1988-10-21 Minolta Camera Co Ltd Electrophotographic copying machine
    JP3518812B2 (en) * 1993-04-30 2004-04-12 株式会社リコー Image forming device
    US5410388A (en) * 1993-05-17 1995-04-25 Xerox Corporation Automatic compensation for toner concentration drift due to developer aging
    US5773827A (en) * 1996-12-16 1998-06-30 Xerox Corporation Xerographic infrared reflectance densitometer (IRD) sensor
    US5966573A (en) * 1998-10-08 1999-10-12 Xerox Corporation Seamed flexible electrostatographic imaging belt having a permanent localized solid attribute

    Also Published As

    Publication number Publication date
    US6434346B1 (en) 2002-08-13
    JP2002509291A (en) 2002-03-26
    EP1047980A1 (en) 2000-11-02
    DE59901179D1 (en) 2002-05-16
    CA2316162C (en) 2007-09-04
    CA2316162A1 (en) 1999-07-22
    WO1999036834A1 (en) 1999-07-22
    WO1999036834A9 (en) 1999-10-14

    Similar Documents

    Publication Publication Date Title
    DE19731251B4 (en) Image forming apparatus and developing method for an image forming apparatus
    DE4411715C2 (en) Color image generating device
    DE102008028248B4 (en) Image forming apparatus and image forming method
    EP1410113B1 (en) Method and device for controlling a print process with high colour density
    DE19837418C2 (en) Imaging apparatus
    DE69531391T2 (en) Method and device for improving the color conflict in a printing device with the first print in black
    DE10111216B4 (en) Printing system and printing process
    DE4340606C2 (en) Color image generator
    EP0403523B1 (en) Electrophotographic printing device with regulated electrophotographic process
    DE102007025700B4 (en) Image forming apparatus and toner adhesion amount correction method
    EP1047980B1 (en) Printing and photocopying device and method whereby one toner mark is scanned at at least two points of measurement
    DE60002416T2 (en) Image generation method and device for effective image density control
    DE4210077C2 (en) Electrophotographic imaging equipment
    DE3627172A1 (en) METHOD AND DEVICE FOR DETECTING AND CONTROLLING THE TONER DENSITY IN COPYING MACHINES
    EP1141787B2 (en) Method and device for adjusting toner concentration in an electrographic process
    DE3728493C2 (en)
    DE19821218C2 (en) A color image forming apparatus for preventing a toner image from shifting on an image carrier
    DE3834232A1 (en) DEVICE AND METHOD FOR RECORDING A COLOR IMAGE
    DE69637039T2 (en) Method for controlling the line width of a toner image
    DE4232232C2 (en) Method and device for applying toner images to a photosensitive medium
    EP1145539B1 (en) Printing methods which are dependent on attributes of the printed image support, and corresponding printing devices
    EP1525514A1 (en) Method and device for setting the toner concentration in the developer station of an electrophotographic printer or copier
    DE3914496A1 (en) TONER DENSITY CONTROL DEVICE FOR A PICTURE GENERATION DEVICE
    DE3342625C2 (en)
    DE3935231C2 (en) Electrophotographic imaging equipment

    Legal Events

    Date Code Title Description
    PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

    Free format text: ORIGINAL CODE: 0009012

    17P Request for examination filed

    Effective date: 20000816

    AK Designated contracting states

    Kind code of ref document: A1

    Designated state(s): BE DE FR GB

    GRAG Despatch of communication of intention to grant

    Free format text: ORIGINAL CODE: EPIDOS AGRA

    17Q First examination report despatched

    Effective date: 20010424

    GRAG Despatch of communication of intention to grant

    Free format text: ORIGINAL CODE: EPIDOS AGRA

    GRAH Despatch of communication of intention to grant a patent

    Free format text: ORIGINAL CODE: EPIDOS IGRA

    GRAH Despatch of communication of intention to grant a patent

    Free format text: ORIGINAL CODE: EPIDOS IGRA

    REG Reference to a national code

    Ref country code: GB

    Ref legal event code: IF02

    GRAA (expected) grant

    Free format text: ORIGINAL CODE: 0009210

    AK Designated contracting states

    Kind code of ref document: B1

    Designated state(s): BE DE FR GB

    REF Corresponds to:

    Ref document number: 59901179

    Country of ref document: DE

    Date of ref document: 20020516

    GBT Gb: translation of ep patent filed (gb section 77(6)(a)/1977)

    Effective date: 20020711

    ET Fr: translation filed
    PLBE No opposition filed within time limit

    Free format text: ORIGINAL CODE: 0009261

    STAA Information on the status of an ep patent application or granted ep patent

    Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

    26N No opposition filed

    Effective date: 20030113

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: FR

    Payment date: 20130207

    Year of fee payment: 15

    Ref country code: GB

    Payment date: 20130125

    Year of fee payment: 15

    Ref country code: DE

    Payment date: 20130325

    Year of fee payment: 15

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: BE

    Payment date: 20130125

    Year of fee payment: 15

    REG Reference to a national code

    Ref country code: DE

    Ref legal event code: R082

    Ref document number: 59901179

    Country of ref document: DE

    Representative=s name: PATENTANWAELTE SCHAUMBURG, THOENES, THURN, LAN, DE

    REG Reference to a national code

    Ref country code: DE

    Ref legal event code: R082

    Ref document number: 59901179

    Country of ref document: DE

    Representative=s name: PATENTANWAELTE SCHAUMBURG, THOENES, THURN, LAN, DE

    Effective date: 20130820

    Ref country code: DE

    Ref legal event code: R081

    Ref document number: 59901179

    Country of ref document: DE

    Owner name: OCE PRINTING SYSTEMS GMBH & CO. KG, DE

    Free format text: FORMER OWNER: OCE PRINTING SYSTEMS GMBH, 85586 POING, DE

    Effective date: 20130820

    REG Reference to a national code

    Ref country code: FR

    Ref legal event code: TP

    Owner name: OCE PRINTING SYSTEMS GMBH & CO. KG, DE

    Effective date: 20140513

    BERE Be: lapsed

    Owner name: *OCE PRINTING SYSTEMS G.M.B.H. & CO. K.G.

    Effective date: 20140131

    REG Reference to a national code

    Ref country code: DE

    Ref legal event code: R119

    Ref document number: 59901179

    Country of ref document: DE

    GBPC Gb: european patent ceased through non-payment of renewal fee

    Effective date: 20140115

    REG Reference to a national code

    Ref country code: GB

    Ref legal event code: 732E

    Free format text: REGISTERED BETWEEN 20140904 AND 20140910

    REG Reference to a national code

    Ref country code: DE

    Ref legal event code: R119

    Ref document number: 59901179

    Country of ref document: DE

    Effective date: 20140801

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: DE

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20140801

    REG Reference to a national code

    Ref country code: FR

    Ref legal event code: ST

    Effective date: 20140930

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: FR

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20140131

    Ref country code: GB

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20140115

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: BE

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20140131