[0001] The present invention relates to a dry type electrophotographic apparatus such as
a laser printer.
[0002] Recently, a drum unit is used in laser printers. This drum unit includes a photosensitive
drum, an electrifying section, a developing section and a transfer section, for example,
and is detachably mounted to the printer cabinet. Particularly, the photosensitive
drum wears out with frequent usage and needs replacing when its service life expires.
The laser printer is designed to permit replacement of the drum unit when the service
life of the photosensitive member expires, thus facilitating the maintenance work.
[0003] There is known a conventional technique which counts the number of prints as the
history of usage of the photosensitive drum for each printer operation in order to
check if the service life of the photosensitive drum has expired, and uses a memory
device to display the count value (see Published Unexamined Japanese Patent Application
No. 62-75468). The use of this technique allows an operator to know how much the photosensitive
drum has worn out or the degree of degradation of this drum more accurately from the
current print number, compared with the case of checking the use period. Upon confirming
the print number having reached an allowable print number by means of an alarm indicator,
the user has only to replace the drum unit. In this manner, it is possible to prevent
the print quality from lowering due to degradation of the photosensitive drum.
[0004] At the time of shipping laser printers of this type, manufacturers normally check
the print quality, etc. by actually making prints several times. In this checking,
the number of prints made is counted and the count value is stored in the memory device.
It is not desirable that the products be shipped in this state. Conventionally, therefore,
the memory device is detached from each printer after the checking, the print number
data stored in this memory device is cleared to "0" using an exclusive read/write
device. The initialized memory device is reinstalled in the laser printer, which will
then be shipped. Further, in maintenance inspection of the printer, it may be checked
whether or not an alarm indication is made when the print number reaches the allowable
print number. The check is executed in such a manner that another memory device having
the desired print number data close to the allowable print number preset by the exclusive
read/write device is temporarily installed in the printer and printing is actually
done under this condition until the allowable print number is reached.
[0005] In short, according to the prior art, when data of the printing history of the photosensitive
drum needs to be temporarily changed in checking printers at the manufacturing stage,
maintenance, etc., an exclusive read/write device should be used, thus reducing the
working efficiency.
[0006] It is therefore an object of the present invention to provide an electrophotographic
apparatus capable of facilitating inspection at shipment and maintenance.
[0007] To achieve this object, there is provided an electrophotographic apparatus according
to claim 1.
[0008] According to this electrophotographic apparatus, the print number data stored in
the nonvolatile recording section can be set to a value close to the allowable print
number in checking at the time of shipment and maintenance. It is therefore possible
to easily check if the indicating section properly functions by repeating the printing
operation several times following the value setting, without requiring a particular
device for this checking.
[0009] This invention can be more fully understood from the following detailed description
when taken in conjunction with the accompanying drawings, in which:
Fig. 1 is a diagram illustrating the internal structure of a laser printer according
to one embodiment of the present invention;
Fig. 2 is a diagram showing the structure of a laser scanner unit shown in Fig. 1;
Fig. 3 is a block diagram showing a control circuit of the laser printer;
Fig. 4 is a circuit diagram specifically illustrating part of the control circuit
shown in Fig. 3;
Fig. 5 is a diagram illustrating the contents of a process condition data table provided
in a ROM shown in Fig. 3;
Fig. 6 is a diagram illustrating the main memory structure of a RAM shown in Fig.
3;
Fig. 7 is a diagram showing an operation section shown in Fig. 4; and
Figs. 8 to 10B are diagrams for explaining the operation of the control circuit shown
in Fig. 3.
[0010] A laser printer according to one preferred embodiment of the present invention will
now be described referring to the accompanying drawings.
[0011] Fig. 1 schematically illustrates the internal structure of the laser printer. This
laser printer comprises a printer cabinet 1, and also comprises a drum unit 2, a laser
scanner unit 5, a transfer charger 7, a paper storage 10, a paper pickup roller 11,
a fixing unit 12, paper discharge rollers 13, a feed motor 14, a fan 15, an interlock
switch 16 and a DC power supply 17 which are disposed in the cabinet 1. The drum unit
2 includes a photosensitive drum 3, an electrification charger 4, a developing unit
6, a cleaning unit 8, and deelectrifying lamp 9, and is detachably mounted to the
center portion of the cabinet 1. The photosensitive drum 3 has a photosensitive surface
and is driven to rotate in one direction in the printing operation. When the drum
unit 2 is mounted to the cabinet 1, the electrification charger 4, the laser scanner
unit 5, the developing unit 6, the transfer charger 7, the cleaning unit 8, and the
deelectrifying lamp 9 are positioned around the photosensitive drum 3 so as to execute
a sequence of electrophotograph processes. The electrification charger 4 electrifies
the photosensitive surface of the photosensitive drum 3, and the laser scanner unit
5 selectively exposes the electrified photosensitive surface using a laser beam emitted
according to print data to thereby form an electrostatic latent image. The developing
unit 6 supplies toner or a developer to the photosensitive surface of the drum 3 to
make the latent image visible as a toner image by the toner sticking on the photosensitive
surface in accordance with the latent image. The transfer charger 7 electrifies a
sheet of print paper and transfers the toner image on the print paper due to electrostatic
attraction. The cleaning unit 8 clears off the unnecessary toner remaining on the
photosensitive surface of the drum 3, and the deelectrifying lamp 9 deelectrifies
charges on this photo-sensitive surface. The paper storage 10 is disposed at the preceding
stage of the transfer charger 7, and the fixing unit 12 and discharge rollers 13 are
disposed in order at the subsequent stage of the transfer charger 7. Sheets of print
paper stored in the paper storage 10 are picked up one at a time by the pickup roller
11 in each print operation, and the print paper is fed to the transfer charger 7 at
a given timing. The fixing unit 12 applies heat and pressure to the print paper to
fix the transferred toner image on the paper.
[0012] As shown in Fig. 2, the laser scanner unit 5 comprises a laser diode assembly 21
for producing a laser beam, a laser controller 22 for driving this laser diode assembly
21, a start sensor 23 formed of PIN diodes which detects the irradiation start position
of the laser beam, a polygon motor 24 for rotating a polygon mirror, a polygon motor
driver 25 for driving the motor 24, and a PLL controller 26 for controlling the rotation
of the motor 24.
[0013] Fig. 3 schematically illustrates the control circuit of the laser printer. This control
circuit includes a CPU (Central Processing Unit) 31 which executes various data processing
required to control the printing operation, a ROM (Read only Memory) 32 which stores
control program for the CPU 31, various data tables, and the like, a RAM (Random Access
Memory) 33 which temporarily stores data input to and output from the CPU 31 such
as print data supplied from an external host computer, an I/O port 34 and a bus line
35 for interconnecting these components.
[0014] The I/O port 34 is connected to the laser scanner unit 5, the fan 15, a motor driver
36, a high voltage supply circuit 37, a sensor driver 40, an operation unit OP, paper
sensors 42 to 44, an interface 45, and a recording section RD. The motor driver 36
controls the driving of the feed motor 14. The high voltage supply circuit 37 supplies
a high voltage to the electrification charger 4, developing unit 6 and transfer charger
7. The sensor driver 40 drives a toner-empty sensor 38 and a toner-full sensor 39,
both provided in the developing unit 6. The paper sensors 42 to 44 are distributed
to detect paper jamming. The interface 45 receives at least a print start command
and print data from the host computer. The nonvolatile recording section RD stores
print number data A representing the number of prints made by the photosensitive drum
3 and allowable print number data B representing the allowable print number which
is determined in accordance with the service life of the photosensitive drum 3 and
at which the drum unit 2 should be replaced. These data A and B are not erased when
the power supply for the printer is cut off. The interlock switch 16 is inserted in
the power supply line which supplies a voltage of +24 V from the DC power supply 17
to the motor driver 36, laser scanner unit 5, high voltage supply circuit 37 and fan
15. This interlock switch cuts off the power supply when the upper part of the printer
cabinet 1 is rocked open. The CPU 31, ROM 32, RAM 33, I/O port 34, and the other components
operate on a voltage of +5 V supplied from the DC power supply 17.
[0015] Fig. 4 illustrates the specific structure of part of the control circuit. In this
circuit, the CPU 31 accesses a memory card 51 via a card interface 52, directly accesses
the ROM 32 and RAM 33, and accesses the operation section 41 via an operation section
interface 53. The memory card 51 serves as a nonvolatile data storage medium detachable
to the interface 52, and has areas in which the print number data A and allowable
print number data B. The CPU 31 sets a reference voltage of an electrification voltage
supply 54 for the electrification charger 4 in a D/A (Digital/Analog) converter 55
and sets a reference voltage of a transfer voltage supply 56 for the transfer charger
7 in a D/A converter 57. The CPU 31 also sets a reference voltage of a bias voltage
supply 58 for the developing unit 6 in a D/A converter 59 and sets the laser output
of the laser controller 22 in a D/A converter 60. In an initial state, the memory
card 51 has the print number data A of "0" and the allowable print number B of "10000".
The print number data A stored in the memory card 51 is incremented by the print number
in each printing operation. The ROM 32 has an area that constitutes a process condition
data table 70 as shown in Fig. 5. This table 70 includes the electrophotograph process
condition data #1 and #2 associated with different print numbers A and selectively
used to compensate for degradation of the print quality caused by the deterioration
of the photosensitive drum 3. These electrophotograph process condition data #1 and
#2 each consist of reference voltage data of the electrification voltage supply 54,
transfer voltage supply 56 and bias voltage supply 58, and the laser output data of
the laser controller 22. As shown in Fig. 6, the RAM 33 has areas that constitute
a print number memory 71 for storing the print number data A retrieved from the memory
card 51 as process data A′, a flag memory 72 for a data set flag F which is set to
"1" when a data set mode is selected, and an allowable print number memory 88 for
storing the allowable print number data B retrieved from memory card 51 as process
data B′. The operation section 41 is provided with a power switch 81, a data set mode
select switch 82, a set key 83, a reset key 84, an UP key 85, a DOWN key 86 and a
liquid crystal display 87. This display 87 displays message or numeral data such as
the print number data A stored in the memory card 51.
[0016] The operation of the thus constituted laser printer will be explained below.
[0017] The CPU 31 is programmed to perform the operation shown in Fig. 8 when the power
switch 81 is operated to activate the laser printer. When this operation starts, the
CPU 3 first executes the initialization to clear the data in the RAM 33 and reset
the I/O port 34, for example. Then, the CPU 31 checks the status of the set mode select
switch 82. When the switch 82 is set ON for the set mode, the data set flag F in the
flag memory 72 is set to "1." When the switch 82 is not set ON, the data set flag
F in the flag memory 72 is reset to "0". After the flag F is set or reset, the CPU
31 sequentially executes a print preparation process and a print process.
[0018] In this print preparation process, the CPU 31 periodically executes a print discrimination
process shown in Fig.9 and a key discrimination process shown in Figs. 10A and 10B.
[0019] When the print discrimination process starts, the CPU 31 first checks if a print
start command is received from the host computer an set in RAM 33. This print discrimination
process is immediately terminated when the print start command is not set. When it
is detected that the print start command is set, the CPU 31 accesses the memory card
51 to read out the print number data A and allowable print number data B from the
card 51.
[0020] When the print number A is equal to or greater than zero and less than B/2, the electrophotograph
process condition data #1 is read out from the condition data table 70 in the ROM
32 and various data included in this data #1 are respectively set in the D/A converters
55, 57, 59 and 60. More specifically, "-6000 V" is set as the reference voltage of
the electrification voltage supply 54 in the D/A converter 55, "-5000 V" as the reference
voltage of the transfer voltage supply 56 in the D/A converter 57, "-300 V" as the
reference voltage of the bias voltage supply 58 in the D/A converter 59, and "3 mW"
as the laser output of the laser controller 22 in the D/A converter 60.
[0021] When the print number A is equal to or greater than B/2 and less than B, the electrophotograph
process condition data #2 is read out from the condition data table 70 in the ROM
32 and various data included in this data #2 are respectively set in the D/A converters
55, 57, 59 and 60. More specifically, "-7000 V" is set this time as the reference
voltage of the electrification voltage supply 54 in the D/A converter 55, "-6000 V"
as the reference voltage of the transfer voltage supply 56 in the D/A converter 57,
"-400 V" as the reference voltage of the bias voltage supply 58 in the D/A converter
59, and "4 mW" as the laser output of the laser controller 22 in the D/A converter
60.
[0022] The CPU 31 terminates the print discrimination process after data are set in the
D/A converters 55, 57, 59 and 60, so as to execute the print process. In this print
process, the electrification charger 4, laser controller 22, developing unit 6, and
transfer charger 7 are activated in order to execute a sequence of electrophotograph
processes based on the values set in the associated D/A converters 55, 57, 59 and
60, printing an image corresponding to print data set from the host computer on the
print paper. Upon completion of one printing operation, the print number data A is
incremented by "1" in the memory card 51.
[0023] When the print number A reaches the allowable print number B, the CPU 31 causes the
operation section interface 53 to display a message requesting replacement of the
photosensitive drum 3 on the liquid crystal display 87, and inhibits the following
printing operation. When the print number A is over the allowable print number B,
the CPU 31 causes the operation section inter face 53 to display a message, indicating
that the data stored in the memory card 51 is inaccurate, on the display 87 and disables
the following printing operation.
[0024] When the key discrimination process starts, the CPU 31 checks in step ST1 whether
or not the data set keys, namely, the set key 83, reset key 84, UP key 85 and DOWN
key 86, have been operated. Upon detection of the key operations in step ST1, the
CPU 31 selectively performs an initializing of data A and B, an updating of data A,
or an updating of data B.
[0025] The initializing of data A and B is performed when it is confirmed that the reset
key 84 has been operated, the data set flag F has been set to "1", and the set key
83 has not been operated. In this initializing, the print number data A of "0" and
the allowable print number data B of "10000" are written in the memory card 51. The
CPU 31 terminates the key discrimination process after the writing.
[0026] The updating of data A is performed when it is confirmed that the reset key 84 has
not been operated, the set key 83 has been operated, and the data set flag F has been
set to "1". In this updating, print number data A is read out from the memory card
51, and written as process data A′ in the print number memory 71. This process data
A′ is read out from the memory 71 and is displayed, blinking, on the liquid crystal
display 87. Then the CPU 31 repeats steps ST2 to ST4 and waits for any of the data
set keys 83, 85 or 86 excluding the reset key 84 to be operated. If the operation
of the UP key 85 is detected in step ST2, "100" is added to the data A′ stored in
the memory 71. The resultant data A′ is read out from the memory 71 and is displayed,
blinking, on the display 87. After the display operation, the CPU 31 waits for the
next key operation. If the operation of the DOWN key 86 is detected in step ST3, "100"
is subtracted from the data A′ stored in the memory 71. The resultant data A′ is read
out from the memory 71 and is displayed, blinking, on the display 87. After the display
operation, the CPU 31 waits for the next key operation. If the operation of the set
key 83 is detected in step ST4, the data A′ stored in the memory 71 is written as
the print number data A in the memory card 51 and is displayed without blinking on
the display 87. After the display operation, the CPU 31 terminates the key discrimination
process.
[0027] The updating of data B is performed when it is confirmed that the reset key 84 and
set key 83 have been operated, and the data set flag F has been set to "1". In this
updating, allowable print number data B is read out from the memory card 51, and written
as process data B′ in the allowable print number memory 88. This process data B′ is
read out from the memory 88 and is displayed, blinking, on the liquid crystal display
87. Then the CPU 31 repeats steps ST5 to ST7 and waits for any of the data set keys
83, 85 or 86 excluding the reset key 84 to be operated. If the operation of the UP
key 85 is detected in step ST5, "100" is added to the data B′ stored in the memory
88. The resultant data B′ is read out from the memory 88 and is displayed, blinking,
on the display 87. After the display operation, the CPU 31 waits for the next key
operation. If the operation of the DOWN key 86 is detected in step ST6, "100" is subtracted
from the data B′ stored in the memory 88. The resultant data B′ is read out from the
memory 88 and is displayed, blinking, on the display 87. After the display operation,
the CPU 31 waits for the next key operation. If the operation of the set key 83 is
detected in step ST7, the data B′ stored in the memory 88 is written as the allowable
print number data B in the memory card 51 and is displayed without blinking on the
display 87. After the display operation, the CPU 31 terminates the key discrimination
process.
[0028] If it is detected that no key operation is detected in step ST1, the operation of
a key other than the set key 83 and reset key 84 is detected, or the flag F has been
reset to "0", the CPU 31 will terminate the key discrimination process without doing
anything.
[0029] In the above-described laser printer, when power is given using the power switch
81 with the data set mode select switch 82 set ON, the data set flag F is set to "1"
to select the data set mode. After that, when the reset key 84 is operated, the print
number data A stored in the memory card 51 connected to the card interface 52 is reset
to "0."
[0030] If the manufacturer operates the laser printer to check the print quality or the
like prior to its shipment, therefore, the print number data A in the memory card
51 installed in the printer can be cleared to "0" by setting the power switch 81 ON
after the checking with the data set mode select switch 82 rendered ON followed by
the operation of the reset key 84. In other words, this printer can permit initialization
of the memory card 51 by a simple operation without requiring a particular read/write
device, and can thus improve the working efficiency in checking before shipment.
[0031] In this laser printer, if the set key 83 is operated under the condition that the
data set mode has been selected, the print number data A stored in the memory card
51 connected to the card interface 52 is read out and temporarily stored as process
data A′ in the print number memory 71, and the process data A′ is displayed blinking
on the liquid crystal display 87. When the UP key 85 is operated in this state, "100"
is added to the process data A′ stored in the memory 71, and the resultant process
data A′ is displayed blinking on the display 87. When the DOWN key 86 is operated,
"100" is subtracted from the process data A′ stored in the memory 71, and the resultant
process data A′ is displayed blinking on the display 87. When the set key 83 is operated
again, the process data A′ stored in the memory 71 at that point of time is written
as the print number data A in the memory card 51 connected to the card interface 52.
This print number data A is also displayed without blinking on the display 87.
[0032] When it becomes necessary to check if an alarm indication is made when the print
number reaches the allowable print number determined in accordance with the service
life of the photosensitive drum in the maintenance inspection of the present laser
printer, therefore, first the data set mode select switch 82 is rendered ON, then
the power switch 81 is set ON in this state followed by the operation of the set key
83. As a result, the print number data A stored in the memory card 51 in association
with the presently mounted drum unit 2 is displayed blinking on the display 87 so
that the operator writes down this number on a memo or the like. Then, the UP key
85 is repeatedly operated to increase the displayed print number by the units of "100".
When this number approaches to the allowable print number, the set key 83 is operated
again. Consequently, the print number close to this allowable print number is written
in the memory card 51. It is therefore possible to check if a message requesting the
drum replacement is displayed by actually making prints until the print number reaches
the allowable print number.
[0033] When the maintenance inspection is completed in this manner, the set key 83 is operated
again with the set mode selected. Then the DOWN key 86 is repeatedly operated to decrement
the displayed print number by the units of "100". When the resultant print number
becomes the print number taken down on the memo plus the number of the prints actually
made in this inspection, the set key 83 is operated again to write the present print
number data in the memory card 51. Therefore, the printing history of the photosensitive
drum in the laser printer can be set back to the correct value as before the maintenance
inspection. Accordingly, it is possible to check if an alarm indication is made when
the print number reaches the allowable print number in the maintenance inspection
or the like by a simple key operation without requiring a read/write device. This
can therefore ensure easier maintenance inspection.
[0034] In this laser printer, if the set key 83 and reset key 84 are operated under the
condition that the data set mode has been selected, the allowable print number data
B stored in the memory card 51 connected to the card interface 52 is read out and
temporarily stored as process data B′ in the allowable print number memory 88, and
the process data B′ is displayed blinking on the liquid crystal display 87. When the
UP key 85 or DOWN key 86 is repeatedly operated in this state, the process data B′
stored in the memory 88 increases or decreases by the units of "100", and the resultant
process data B′ is displayed blinking on the display 87. When the set key 83 is operated
again, the process data B′ stored in the memory 88 at that point of time is written
as the allowable print number data B in the memory card 51 connected to the card interface
52. This allowable print number data B is also displayed without blinking on the display
87. Since the allowable print number B can be updated, it is possible to cope with
the case where the service life of the photosensitive drum is changed by replacement
of the drum unit.
[0035] In the embodiment, the UP key 85 and DOWN key 86 are provided to increase and decrease
the number data stored in the memory card 51 by the units of "100". Instead, numerical
keys may be provided to directly set the desired number, for example. Although the
memory card 51 is used as an example of the data recording medium in the above embodiment,
a magnetic tape or other types of recording media may be employed as well. The recording
medium may also be a semiconductor memory such as E² PROM or RAM with power backup.
Further, the present invention is not restricted to a laser printer, but may also
be applied to a copying machine in which a drum unit having a photosensitive member
is detachably mounted to the cabinet.
1. An electrophotographic apparatus comprising:
printing means (2, 5, 12), having a photosensitive member (3) to be replaced when
its service life expires, for forming an electrostatic latent image on said photosensitive
member (3), developing the electrostatic latent image by applying developer to said
photosensitive member (3), and transferring the developed image on a sheet of print
paper;
nonvolatile recording means (RD) for storing at least print number data representing
the number of prints made by said photosensitive member (3); and
indicating means (87) for informing that the print number data stored in said recording
means reaches an allowable print number determined in accordance with the service
life of said photosensitive member (3);
characterized in that
said electrophotographic apparatus further comprises update means (31, 32, 33,
81 -86) for setting the print number data stored in said recording means (RD) to a
value close to the allowable print number when the operation of said indicating means
(87) is checked,
and in that said update means (31, 32, 33, 81 - 86) includes means for setting
said print number data stored in said recording means (RD) to zero when the recording
means (RD) is initialized.
2. An electrophotographic apparatus according to claim 1, characterized in that said
recording means (RD) further stores allowable print number data representing said
allowable print number, and said update means (31, 32, 33, 81 - 86) includes means
for changing said allowable print number data when said photosensitive member (3)
is replaced.
3. An electrophotographic apparatus according to claim 1, characterized in that said
update means (31, 32, 33, 81 - 86) includes an input section (81 - 86), a memory (33),
and data processing means (31) for transferring data stored in said recording means
to said memory, changing the data stored in said memory (33) in accordance with the
operation of said input section (81 - 86), and transferring the data stored in said
memory (33) to said recording means (RD).
4. An electrophotographic apparatus according to claim 1 characterized in that said electrophotographic
apparatus further comprises a cabinet (1), and in that said printing means (2, 5,
12) includes a unit (2) detachably mounted to said cabinet (1) and constituted by
at least said photosensitive member (3).
1. Elektrofotografisches Gerät, mit:
einer Druckeinrichtung (2, 5, 12), die ein nach Ablauf seiner Standzeit auszuwechselndes
lichtempfindliches Teil (3) aufweist, um ein latentes elektrostatisches Bild auf dem
lichtempfindlichen Teil (3) zu bilden, das latente elektrostatische Bild durch Aufbringen
von Entwickler auf das lichtempfindliche Teil (3) zu entwickeln und das entwickelte
Bild auf ein Druckpapier zu übertragen;
einer nicht löschbaren Aufzeichnungseinrichtung (RD) zum Speichern zumindest der Druckanzahldaten,
die die Anzahl der von dem lichtempfindlichen Teil (3) erzeugten Drucke darstellen;
und
einer Anzeigeeinrichtung (87) für die Information, daß die in der Aufzeichnungseinrichtung
gespeicherten Druckanzahldaten eine zulässige Druckanzahl erreichen, die entsprechend
der Standzeit des lichtempfindlichen Teils (3) festgelegt ist;
dadurch gekennzeichnet, daß
das elektrofotografische Gerät ferner eine Fortschreibeeinrichtung (31, 32, 33, 81
- 86) aufweist, um die in der Aufzeichungseinrichtung (RD) gespeicherten Druckanzahldaten
auf einen Wert nahe bei der zulässigen Druckanzahl zu setzen, wenn der Betrieb der
Anzeigeeinrichtung (87) kontrolliert wird,
und daß die Fortschreibeeinrichtung (31, 32, 33, 81 - 86) eine Einrichtung aufweist,
um die in der Aufzeichnungseinrichtung (RD) gespeicherten Druckanzahldaten auf Null
zu setzen, wenn die Aufzeichnungseinrichtung (RD) initialisiert wird.
2. Elektrofotografisches Gerät nach Anspruch 1, dadurch gekennzeichnet, daß die Aufzeichnungseinrichtung
(RD) ferner zulässige Druckanzahldaten speichert, die die zulässige Anzahl der Drucke
darstellen, und daß die Fortschreibeeinrichtung (31, 32, 33, 81 - 86) eine Einrichtung
aufweist, um die zulässigen Druckanzahldaten zu ändern, wenn das lichtempfindliche
Teil (3) ausgewechselt wird.
3. Elektrofotografisches Gerät nach Anspruch 1, dadurch gekennzeichnet, daß die Fortschreibeeinrichtung
(31, 32, 33, 81 - 86) einen Eingabebereich (81 - 86), einen Speicher (33) und eine
Datenverarbeitungseinrichtung (31) aufweist, um die in der Aufzeichnungseinrichtung
gespeicherten Daten in den Speicher zu übertragen, die in dem Speicher (33) gespeicherten
Daten in Übereinstimmung mit dem Betrieb des Eingabebereiches (81 - 86) abzuwandeln
und die in dem Speicher (33) gespeicherten Daten zu der Aufzeichnungseinrichtung (RD)
zu übertragen.
4. Elektrofotografisches Gerät nach Anspruch 1, dadurch gekennzeichnet, daß das elektrofotografische
Gerät ferner ein Gehäuse (1) aufweist und daß die Druckeinrichtung (2, 5, 12) eine
Einheit (2) enthält, die aufsteckbar an dem Gehäuse (1) angebracht ist und zumindest
von dem lichtempfindlichen Teil (3) gebildet wird.
1. Appareil électrophotographique, comprenant :
un dispositif d'impression (2, 5, 12) ayant un organe photosensible (3) normalement
remplacé lorsque sa durée de service arrive à expiration, destiné à former une image
électrostatique latente sur l'organe photosensible (3), à développer l'image électrostatique
latente par application d'un agent de développement sur l'organe photosensible (3),
et à reporter l'image développée sur une feuille de papier d'impression,
un dispositif (RD) d'enregistrement permanent destiné à conserver au moins les
données de nombre d'épreuves représentant le nombre d'épreuves formées par l'organe
photosensible (3), et
un dispositif indicateur (87) destiné à donner une information relative au fait
que les données de nombre d'épreuves conservées dans le dispositif d'enregistrement
atteignent un nombre permis d'épreuves déterminé d'après la durée de service de l'organe
photosensible (3),
caractérisé en ce que
l'appareil électrophotographique comporte en outre un dispositif de remise à jour
(31, 32, 33, 81-86) destiné à établir les données de nombre d'épreuves conservées
dans le dispositif d'enregistrement (RD) à une valeur proche du nombre permis d'épreuves
lorsque le fonctionnement du dispositif indicateur (87) est vérifié, et
le dispositif de remise à jour (31, 32, 33, 81-86) comporte un dispositif destiné
à établir les données de nombre d'épreuves conservées dans le dispositif d'enregistrement
(RD) à zéro lorsque le dispositif d'enregistrement (RD) est initialisé.
2. Appareil électrophotographique selon la revendication 1, caractérisé en ce que le
dispositif d'enregistrement (RD) contient en outre des données de nombre permis d'épreuves
représentant le nombre permis d'épreuves, et le dispositif de remise à jour (31, 32,
33, 81-86) comporte un dispositif destiné à changer les données de nombre permis d'épreuves
lorsque l'organe photosensible (3) est remplacé.
3. Appareil électrophotographique selon la revendication 1, caractérisé en ce que le
dispositif de remise à jour (31, 32, 33, 81-86) comprend une section d'entrée (81-86),
une mémoire (33) et un dispositif (31) de traitement de données destiné à transférer
les données mémorisées dans le dispositif d'enregistrement à la mémoire, à changer
les données conservées dans la mémoire (33) d'après le fonctionnement de la section
d'entrée (81-86), et à transférer les données conservées dans la mémoire (33) au dispositif
d'enregistrement (RD).
4. Appareil électrophotographique selon la revendication 1, caractérisé en ce que l'appareil
électrophotographique comporte en outre un coffret (1), et en ce que le dispositif
d'impression (2, 5, 12) comprend un ensemble (2) monté de façon amovible sur le coffret
(1) et constitué par l'organe photosensible au moins (3).