GB2389196A

GB2389196A - A development process cartridge with a re-programmable memory device.

Info

Publication number: GB2389196A
Application number: GB0207914A
Authority: GB
Inventors: Stephen Bassett; Gregory V Thompson
Original assignee: PBT International Ltd
Current assignee: PBT International Ltd
Priority date: 2002-04-05
Filing date: 2002-04-05
Publication date: 2003-12-03
Also published as: GB0207914D0

Abstract

A development process cartridge for use with a photocopier or printer is provided with a re-programmable memory device thereby permitting reconditioning and re-use of the process cartridge in the same or different printer The memory device is provided with its own power supply (4). . In addition the device provides toner low and full status readings for the user throughout the entire life of the process cartridge of the printer. Once the cartridge has reached the end of its first life cycle a trained operative may recondition the process cartridge to render it capable of another cycle in either the same printer or alternatively configure it for another cycle in a different printer.

Description

( 2389196

FIELD OF THE INVENTION

The present Invention relates to an Image forming apparatus such as an electro photographic printer or copier and In particular to a detachable process cartridge otherwise known as a print development unit, for such equipment provided with a 5 memory device capable of responding to information received from the processing circuit of the printer relating to the use and life of the print development unit BACKGROUND OF THE INVENTION

to Detachable process cartridges for Image forming apparatus such as photocopiers and printers have been in use for some years Such process cartridges house mayor components of photocopiers and printers which during use become depleted such as toner material held In a reservoir, or worn such as the print developer unit, cleaner unit and the photoconductve drum As a result the process cartridge has to be replaced either by a brand new process cartridge or one that has been reconditioned Toner material has also constantly to be replenished with time. Such reconditioning Will Include refilng with toner and the replacement of other appropriate imaging materials.

Various systems that Incorporate electronic memory devices have been incorporated into replaceable process cartridges over recent years to monitor the operation of its various component parts for example by Canon as disclosed In U.S. patent 4,551,000 and by Lexmark In U S patent 5,995, 774 Thus for 25 example an electronic counter circuit has been Incorporated within an electronic memory to store the number of operations of the photoconductive drum and thereafter to provide a particular observable output signal acting as a warning

4; l indicator that the service life of the photoconductive drum has or Is about to expire. In some cases such memory devices are adapted to prevent or discourage the 5 subsequent reconditioning and reuse of the print development unit or the memory devices themselves once its operating components have completed one cycle and the toner in the print development unit Is depleted For example the Optra T Senes of printers sold by Lexmark International Inc of to the United States of America Include a memory device In the form of an EPROM which has a number of lock out bits which prevents reuse of the print development unit when the toner material has been depleted. This same type of device is also employed by Toshiba in some of its e-studio punters and by NRG in its range of printers.

Consequently If the level of toner In the print development unit increases by a significant amount by being refilled, the printer will lock out and prohibit operation of the same (or different) punter with that particular unit 20 The same series of printers also restrict the use of alternative pnot development units by checking for the presence of a manufacturers serial number stored In the EPROM. If the serial number Is not present or the one that Is does not correspond to a valid number, then the printer Will display an error message preventing any further use of the print development unit

t,. crap f By these means the print development unit once it has completed one cycle of use, cannot be reconditioned or reused by having the toner level replenished, and therefore may be discarded This is wasteful of resources.

5 SUMMARY OF INVENTION

It is an object of the invention to overcome the disadvantages of the prior art and

to provide a process cartridge for use with a photocopier or printer provided with a reusable memory device thereby permitting reconditioning and reuse of the process cartridge In the same (or different) printer In addition the device will 10 provide full and toner low status readings for the user throughout the entire life of the print development unit Once the unit has reached the end of its first life cycle then a trained and equipped operative may then re-condton the print development unit to render it capable of another cycle In the same printer or configure it for another cycle In a different punter.

According to the Invention there Is provided a memory device for use with a replaceable process cartridge for image forming apparatus such as a laser punter the process cartridge housing as its components parts a toner reservoir, a photoconductive drum, cleaning unit and a print developer unit, said device 20 comprising a pair of contacts for matching with contacts on the printer connected to the processing circuit of the printer, selectively reprogrammable memory means which can be programmed to respond to a first series of signals from the processing circuit of the printer to provide an Indication of compatibility with said processing circuit and subsequently to a second series of signals to cause the 25 memory means to provide a first Indication that the toner reservoir of the process cartridge is full and a second indication that the toner reservoirs empty, and a power supply independent of the printer for operating the memory means to

l dI d' provide a reversible record of usage thereby to enable the toner reservoir to be refilled and the cartridge reused or the cartridge to which the memory means Is attached to be reconditioned and reused at the end of its useful life 5 Advantageously the memory means includes and EEPROM having an electrically erasable memory including a temporary memory for storing Information in response to said second series of signals as an indication of the live status of the cartridge. 0 BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will become apparent from the following description of a preferred embodiment of the Invention taken

with reference to the accompanying drawings wherein Figure 1 Is an upper perspective view of a memory device In accordance with the invention for attachment to a detachable print development unit for an electro photographic printer or copier, figure 2 is an underneath view of the device of figure 1, Figure 3 shows the device of figures 1 and 2 detachably mounted to a detachable print development unit for use with an electric photographic printer or copier; 25 Figure 4 is a schematic circuit diagram of the memory device In accordance with the invention,

i,:d t:l't: I':' Figure 5 Is a flow diagram Illustrating how the memory device In accordance with the invention checks for compatibility with the processing circuit of an electrophotographic punter; 5 figure 6 Is a flow diagram Illustrating how the memory device In accordance with the Invention interfaces with the processing circuit of a printer to monitor toner level depletion and Figure 7 is a block schematic diagram illustrating the Interface relationship to between the punter and the replaceable print development unit housed therein and provided with a memory device in accordance with the Invention PREFERRED EMBODIMENTS OF THE INVENTION

The memory device shown in the drawings and particularly In Figs 1, 2 and 3 Is 15 designed specifically for use with the Lexmark Optra T and SE series of printers sold by Lexmark International inc of the L1 S A This Is not a limiting factor of the Invention however since the device can be adapted and programmed for use with other printers such as for example those 20 sold by Toshiba and NRG As referred to earlier Lexmark Optra T printers employ a detachable print development unit provided with an EPROM which communicates with the processor circuit of the printer to cause a bit In the EPROM to be permanently 25 burned after a given amount of toner has been used

: : (1 As a result if an attempt Is made to replenish the development unit with toner material, the printer will lock-out In effect the unit Is no longer useable even though there Is still life left In it as regards wear and tear on the operative component parts of the development unit.

The interface between the processing circuit of the Lexmark Optra T and SE series of printers and the EPROM circuit on the Optra T detachable print development unit for those printers is also designed such that operation of the unit is locked out if there is a discrepancy between a serial number stored In the to EPROM circuit and the valid manufacturers serial number These prior designs represent efforts made by manufacturers to prevent re-use and or re-condtionng of their print development units and moreover to prevent them from functioning even if their operating parts are not worn out, simply by ts replenishment of toner material The earlier Lexmark Optra S series of printers use a detachable pent development unit which Is not as sophisticated as the Optra T series In terms of the use of a memory circuit which Interfaces with the processing circuit of the 20 printer whereby to Inhibit replenishment of toner material and eventual re conditioning once the unit Is worn out.

A basic aim of the present Invention Is to provide a memory device which can be attached to the Optra S series of detachable print development units and designed to interface with the processing circuit of the Lexmark Optra T series of printers in a totally different manner compared to the workings of the memory device incorporated in the Optra T print development units by the manufacturer

l ;; d l l This will become clear from the description of a preferred embodiment of the

invention as appearing hereinafter 5 The memory device shown in figure 1 for mounting on an Optra S detachable process cartridge for eventual use with the Lexmark Optra T and SE series of printers comprises a support plate 1 mounting an electronic memory in the form of an EEPROM processor 2 connected to two sets of contacts 3 which make contact with the processing circuits of the printer when the cartridge is inserted 10 therein to receive data from the printer relating to operational usage and for addressing the EEPROM processor 2 which Is pre-programmed In a fashion which Will become evident as this descnpton proceeds The device is powered by rechargeable or replaceable batteries 4 mounted on 15 the support plate 1 and includes a power Interruption device 5 which enables a fast and simple controlled reset of the programme and memory in the EEPROM processor 2 The support plate 1 has flexible mounting plates 6 as shown in Figure 2 to 20 maximse the contact between the contacts 3 and the processing circuit of the printer. The mounting plates are designed for releasable attachment of the memory device to the process cartridge 7 of a printer as shown In Fig 3 The EEPROM processor 2 has three areas of memory being an electrically 25 erasable programmable read-only memory, temporary memory where life storage indications are stored and can provide a reversible record of usage and an area

of flash memory which Is used to store the program script used during processing in the application of the invention Since it can be re-set and reprogrammed the memory device in accordance with 5 the invention can be used repeatedly either on the same print development unit or on another unit thus avoiding wastage as with the prior art

The memory device In accordance with the Invention for mounting on a pant development unit such as the Lexmark series of printers Is provided with an to independent power supply 4 so that it can perform unilaterally and does not have to depend on the power supply to the printer The operation of the memory device in accordance with the Invention when used in conjunction with the processing circuit of a Lexmark Optra T or SE printer may 5 be demonstrated with reference to Figs 4 through Fig 7, Fig 7 In particular being a representation in block form of the processing interface between the Optra T development unit PDU provided with an EEPROM processing circuit In accordance with a preferred embodiment of the Invention, and a Lexmark printer p A device tab 9 on the memory device shown in Figure 3 and in the flow diagram of Fig 5 is removed prior to Insertion in the printer (not shown) which then enables power to reach the EEPROM processor 2 The processor 2 then sits In normal mode see Fig 5 until the two contacts within the printer make contact with 25 the contact plates 3 of the memory device mounted on the print development unit 7. Once the lid of the printer is closed a micro switch initiates a request by the printer to verify the identity of the unit Inserted.

) This is done in the following way A voltage drop occurs on the data line feed 8 of the EEPROM processor 2, see Fig 4, which Initiates a wake up programme In the EEPROI\/I processor 2 The printer also sends a request to view the contents of a number of addresses in the processor 2 The EEPROM processor 2 processes this request and then returns the information that the printer should continue to function 10 The printer P then copies a set of variables to its RAM address 10, see Fig 5 and 7. The printer P also checks that the yield wheel toner sensor mechanism 11, see Fig 5 is of the type acceptable to the EEPROM processor 2 If there is a match then the printer 2 continues,orocessng if there Is not then the 5 primer displays an error message on display 12 Dunng the pnotng process toner contained in the print development unit 7 Is used. Once the mechanism of the printer P detects that a critical transition has occurred then the printer P compares the new status with the status of the stored 20 data in its NVRam 11 and then sends a write command to the EEPROM 2 The EEPROM 2 processes the command and once the printer sends the command with the address determining that the toner has been depleted the program recognises the command and will then write "the flag" for toner low 2s The device can be reset by operation of the Interruption device 5 This would normally be earned out by the operative reconditioning the printer development unit using for example an tnsuiated non conductive Instrument to slide between

hi J() the contacts on the interrupt devices This would momentarily deplete the device of power and so remove from the memory of the EEPROM 2 any written data The EEPROM processor 2 also has pins which can be accessed using a PC 5 interface board to erase the current program and load an aiternat/ve program compatible with the processing circuit of another manufacturer's punter.

As indicated above the present invention has particular appiicat/on to use with the Lexmark Optra T and SE series of printers It Is adaptable however as Will be to evident to those skilled m the art to other printers by virtue of its reprogramming ability to suit requirements. The applicant Is the first of its knowledge to provide a print development unit with a reprogrammable memory device having the versatility and adaptability as that In accordance with the present invention and which will allow the print development unit to which it Is attached to be 5 replenished with toner material throughout the life of the cartridge and thereafter to be reconditioned and reused with the same memory device

Claims

( CLAIMS

1. A memory device for use with a replaceable process cartridge for image 5 forming apparatus such as a laser punter the process cartridge housing as its components parts a toner reservoir, a photoconductve drum, cleaning unit and a print developer unit, said device comprising a pair of contacts for matching with contacts on the printer connected to the processing circuit of the printer, reprogrammable memory means which can be programmed to respond to a first 10 series of signals from the processing circuit of the punter to provide an indication of compatibility with said processing circuit and subsequently to a second series of signals to cause the memory means to provide a first indication that the toner reservoir of the process cartridge is full and a second indication that the toner reservoir is empty, and a power supply independent of the printer for operating the 15 memory means to provide a reversible record of usage thereby to enable the toner reservoir to be refilled and the cartridge reused or the cartridge to which the memory means is attached to be reconditioned and reused at the end of its useful life

2 A memory device as claimed In claim 1 wherein the memory means includes 20 an EEPROM having an electrically erasable memory Including a temporary memory for storing inforrnaton in response to said second series of signals as an indication of the life status of the cartridge

3. A memory device as claimed In claim 2 wherein the memory means Includes a power interruption device to enable a controlled reset of the programme in the EEPROM memory.

5

4. A memory device as claimed in any preceding claim wherein said power supply is in the form of replaceable or re-chargeable batteries for powering the memory means

5. A detachable cartridge provided with a memory device as claimed In any 10 preceding claims.

6 A memory device substantially as hereinbefore described with reference to and as i!!ustrated en the accompanying drawings.

15 7. A detachable cartridge for an Image forming apparatus such as a laser printer substantially as herenbefore described with reference to and as illustrated in the accompanying drawings