Patent Application
20080050147
The present invention relates to a casing for an electronic circuit, and more particularly to a casing for housing an electronic circuit for use in a remanufactured replaceable consumable unit. A typical replaceable consumable unit such as a toner cartridge, ink jet cartridge, Organic Photo Conductor (OPC) drum assemblies or the like may be used in various types of imaging devices such as printers, copiers, or fax machines. These replaceable consumable units may contain many different components. Some examples of components may include toner, ink, the OPC drum, developer roller, electronic circuits and so forth. The replaceable consumable units may also vary between monochrome and color based devices. As technology continues to change, there is no end in sight to the variations of replaceable consumable units that will be necessary to interoperate with new imaging devices.
Along with the moveable parts, imaging device manufacturers have also started storing information on the replaceable consumable unit. In some of the earlier replaceable consumable units, the Original Equipment Manufacturers (OEM's) devised a way of detecting specific information that was stored on the replaceable consumable unit itself. This was done via a mechanical process. With electronic circuits becoming smaller in physical size, more efficient in terms of increased storage capacity and able to perform more complex tasks, imaging devices are increasingly moving additional information to the replaceable consumable units. For example, information such as operating voltage, cartridge serial number, manufacturing history, printer history, toner consumption, and remaining toner may be stored within memory on the cartridge. This allows the information associated with a specific replaceable consumable unit to move with the replaceable consumable unit should it be transported from one imaging device to another. It also allows the manufacturer to track the cartridge during its lifetime.
In order to protect its profitability, some OEM's have designed the replaceable consumable unit to be a single use product. Once the product had reached the end of its life, the OEM anticipated that the consumer would discard the used part and replace it with a new replaceable consumable unit. Additionally, the OEM has ensured that the replaceable consumable units may not simply be refilled with toner and placed back into service, by installing protection measures on the replaceable consumable unit. For example, OEM's have installed a one-time writable electronic circuit onto the replaceable consumable unit itself. The imaging device has the ability to interface with this electronic circuitry and once this circuit has been disabled, the replaceable consumable unit ceases to function.
An industry known as the Remanufacturing Industry has evolved to address the refurbishing of these replaceable consumable units. Even though the OEM's may have initially wanted the replaceable consumable unit to be single use only, many of the components and assemblies were still reusable. The remanufacturer may be able to take the spent replaceable consumable unit, disassemble it, replace the worn or broken components and then reintroduce the recycled product back into the stream of commerce. Part of the refurbishment process may include the removal of electronic circuitry mounted on the replaceable consumable unit.
During the refurbishment process, one problem encountered with the current designs of replaceable consumable units is that the electronic circuitry may not be easily physically removed. The electronic circuitry is usually mounted on the exterior of the replaceable consumable unit and held in place with some type of adhesive. The area where the electronic circuit is mounted may be cramped with no space to insert a removal tool. The present invention is intended to facilitate the removal process.
In accordance with an embodiment of the present invention, a casing used to house an electronic circuit includes a plurality of walls, and a feature for making the casing easier to remove. This feature may be a protrusion or the like that allows a service technician to use a tool to pry the casing away from the replaceable consumable unit by applying pressure against the feature and the area on the replaceable consumable unit to which the casing is mounted. The feature may also be an indentation that allows the service technician to place a tool between the casing and the replaceable consumable unit. The feature may also take the form of a fixture formed on the casing that may be used by the service technician to pull the casing away from the replaceable consumable unit without having to pry the casing.
The following detailed description of preferred embodiments refers to the accompanying drawings which illustrate specific embodiments of the invention. Henceforth the embodiments of the present invention will be described with reference to a toner cartridge for use in a printer. Other embodiments having different structures and operations do not depart from the scope of the present invention.
The newer toner cartridges have an electronic circuit, which is utilized for various functions. This circuitry may be used to store information that is unique to the specific toner cartridge. Information that may be stored in this electronic circuit may include data such as the serial number of the cartridge, the model type, the yield, the amount of toner remaining and so forth. The printer may periodically access the information stored in the electronic circuit during the life cycle of the cartridges. Whenever the cover of a printer is opened or if the power is turned back on, the printer may query the printer cartridge to obtain its current status. This query may be due to the fact that the printer does not know if it is the same cartridge that was installed prior to the opening and closing of the printer cover. The printer may need to know the cartridge characteristics of the cartridge since it may set certain parameters based on this information.
This electronic circuit has also been used to thwart any recycling of these replaceable consumable units by third parties not affiliated with the OEM. The OEM's have employed various methods to make any refurbishment of the cartridges extremely difficult if not impossible. To begin with, the circuit is designed to become disabled by the printer once the toner level has reached an empty state. Another level of difficulty is that the two components may employ a unique communication scheme. Additionally, the printer might require a validation of the communication. Another level of difficulty that the printer could employ could involve an encryption of the communications in addition to the validation. The list of different ways to encode this information and lock out a third party is endless.
A replacement electronic circuit may be introduced to repair the nonfunctional original electronic circuit during the refurbishment process. This replacement electronic circuit may allow the circuit to still operate, but all communications with the printer would be intercepted. The replacement electronic circuit may have the capability of monitoring the communications going back and forth between the printer and the original electronic circuit. By monitoring the communications coming from the printer, the replacement electronic circuit may intercept, process and resend the data to the original electronic circuit. The original electronic circuit responds accordingly and this is retransmitted to the printer. A processor may also be able to determine when the specific memory locations corresponding to the toner level are being accessed and will subsequently use its own memory locations to store this information. The processor in the recent example may provide a new memory location that would store the toner bucket level. Once the cartridge using the replacement electronic circuit has depleted all of the usable toner the printer will once more write the appropriate value in the correct memory location and the processor may be instructed to disable the ability to change this memory location. The cartridge may then be sent back to be recycled.
In order for the replacement electronic circuit mounted on a replaceable consumable unit to function properly, the replacement electronic circuit must effectively communicate with the printer. As is common in any bi-directional communication architecture, both communicating devices may be able to send and receive information according to an agreed upon protocol and timing criteria. Each printer or family of printers may employ unique protocol schemes. In another illustration, the replacement electronic circuit may communicate with the printer via a one-wire bus architecture protocol. This is the protocol used by several different OEM printer manufacturers. This protocol is based on a one-wire standard developed by Dallas Semiconductor. The printers employing this standard may use a Dallas DS2432 chip to facilitate the communications function on the replaceable consumable unit. Any replacement circuit must be able to emulate this protocol.
The Dallas DS2432 chip also employs a verification technique called SHA-1 or Secure Hash Algorithm-1. This hash algorithm was first created for the Federal Government to be used in conjunction with an encryption scheme. The difference between an encryption algorithm and a hash algorithm is that the hash is unidirectional or one way only. Once information is encoded into an encryption scheme, the data may be extracted once the key is used to unlock the information. This is in contrast to the hash computation because the data is not recoverable once it is used in computing the hash. The hash algorithm is used as a complex way of verifying data integrity similar to the basic cyclic redundancy check that exists in many of the early data communication designs. The SHA-1 algorithm has become an accepted standard for data transmission verification. It uses a complex scheme of mathematical equations and data manipulations to “process” a 64-byte input and determine a 20-byte response sequence. What makes this process unique, when applied in conjunction to this Dallas part, is that of the 64-byte input, 8-bytes are pseudo random data that is stored in a “secret” location which is unreadable. These 8-bytes are downloaded into the part when it is initially stored with data at the factory. Anyone who is skilled in the art might be able to decipher the formula for determining this random data being loaded into this secret location by crunching all of the different possible combinations of the 8-bytes. The total number of combinations would be roughly 1.845×1019. As one could imagine the number crunching might possibly take years if all the possible combinations were tested.
When refurbishing replaceable consumable units, remanufacturers have been limited in what they are able to do to repair these circuits once they have become disabled. If a completely independent replacement circuit were to be developed, it would have to be able to implement this random number. Without the actual knowledge of how it is generated, a remanufacturer would have to generate random numbers until one could be found that would be compatible with a certain set of circuit data. It is analogous to searching for the proverbial needle in a haystack. Absent the ability to decipher the hash, a replacement electronic circuitry is essentially worthless without the original electronic circuit. As pointed out previously, these techniques may be proprietary or extremely difficult to understand. Thus the printer and electronic circuit must be able to communicate and “shake hands” in order for a toner cartridge with such circuitry to be functional within the printer. One aspect of the present invention takes advantage of the nonfunctional electronic circuits capability to speak the unique language as well as employ the encryption protocol. Additionally, once the authentication sequence has been deciphered, a fully functional replacement device employing this technique may be offered utilizing this scheme.
In order to interface with the electronic circuit some printers use electrical contacts. When the toner cartridge is inserted, these printer contacts make an electrical connection with the contacts of the electronic circuit.
Examining some of the prior art toner cartridges, one can show an excellent application of the previously discussed principles.
Other printers may incorporate a wireless communication method to interface to the circuit on the toner cartridge. The same concepts regarding storage of information as applied in the previous prior art cartridge have been adapted for use in the wireless applications. In making the recycling process for the toner cartridge more difficult, the wireless example disables the circuit on the replaceable consumable unit once it has determined that no usable toner remains in the cartridge. To disable the cartridge the printer will write a “disable” value to a specific location in the memory of the circuit. Once written, this memory address may not be overwritten. Simple replacement of this circuit may not be feasible if the communication between the printer and the cartridge employs a unique language or encryption. Therefore, the present invention is applicable to both types of printers since the replacement electronic circuit will take advantage of the original electronic circuit's ability to speak the printer language as well as provide a new memory location for this disabling value.
As applied to the contact toner cartridge, a 16-bit processor may be used. These types of processors may provide a way to communicate between the nonfunctional original electronic circuit on the toner cartridge and the printer. The characteristics that are to be taken into account when choosing a processor is the processor's ability to function at low voltages, low power dissipation, and low cost. In this particular application the processor may be limited to an operating voltage that may vary between about 3.0 V DC and about 4.2 V DC. An additional design restriction for this replacement electronic circuit may be the amount of current that will be able to be sourced at any given time. One possible processor that might be used in an embodiment of the present invention may be the Texas Instruments MSP430F1121A, as this particular processor may operate within the guideline parameters.
When a replacement electronic circuit is installed in conjunction with an original electronic circuit, the replacement electronic circuit together with the original electronic circuit may not exceed the power limitations of the printer supply. The power for these circuits will be derived from the one-wire contacts. Under normal operating conditions this particular microcontroller will require approximately 160 μA to function. When evaluating a replacement circuit alternative, caution must be taken not to overdrive the printer data circuit. Not only must the communications be conducted over these contacts but the power to run these devices must also be supplied from them as well.
Due to size constraints of the replacement electronic circuit, a battery may not be the most feasible alternative to power the processor. A capacitor 51 may be used to store enough voltage potential while the communications line is driven low due to communications taking place. In the preferred embodiment, a 22 μF capacitor 51 may provide enough current to keep the processor operational. In addition, a special reset circuit 102 may be used to ensure the stable operation of the processor. The purpose of this circuit is to allow enough time for the power rail to reach a minimum threshold and remain at or above that minimum level before allowing the processor to start operating. During insertion of the toner cartridge into the printer, the power applied to the replacement electronic circuit data contact 32 the original electronic circuit may fluctuate for a brief period of time. This reset circuit 102 may attempt to ensure that the power rail has had enough time to stabilize before starting the processor. As a result, the reset circuit 102 may hold the reset line of the processor 101 low for an additional 200-300 mS after a 2.25VDC threshold has been reached. Delaying the processor 101 from starting until the power rail has become stabilized may ensure that the processor has enough power to run. In addition, a Shottky diode 53 may be placed in the design to prevent any reverse current from flowing from the capacitor 51 to the printer during times when the printer is driving the data line low.
This processor 101 may be initially programmed using a unique programmer. In this embodiment, the processor may need separate contacts that will allow subsequent reprogramming. This may be due to the processor requiring approximately 6.2-6.8 V DC in order to burn the appropriate memory locations. The processor may be programmed either serially via the data line of the circuit or via a parallel bus. Programming the device via the parallel bus may be accomplished more efficiently by reading and writing in bytes as opposed to bits. Conversely, the handshaking that occurs in the serial procedure will slow down the programming process. However, by having a serial process available, the design becomes more adaptable due to the fact that during the refurbishment process the microprocessor may be reprogrammed by the use of a special dongle. The processor may also be reprogrammed while still mounted on the replaceable consumable unit. This saves time and effort by not having to remove the chip, reprogram it and then reattach it.
Another major advantage of using a processor in this embodiment is that the design may be modified at a later date simply by reprogramming the device. If flexibility or adaptability may be an essential element in the design of a replacement electronic circuit, then discrete logic may not be the best alternative. By using a processor that contains intelligence, the replacement electronic circuit may also be utilized to perform additional functions that the original electronic circuit is incapable of doing. The processor 101 may be able to monitor the communication that occurs between the printer and the toner cartridge and take the appropriate action.
The printer may receive the appropriate hash and determine that it could allow information to pass down to the replaceable consumable unit. The next phase may be to read additional information stored on the device such as the current bucket level. For this to occur, the printer may start the communication as shown in block 201. This time however, no authentication sequence may be necessary because the printer has previously recognized and acknowledged the identity of the cartridge. Therefore, the function may be either a read or a write to memory locations. The processor 101 may determine if it is a read request in block 207, and if so it may access the information in block 208 and pass it along to the printer. If it is not a read request, it may be a write request, and as a result, the information may be stored by the processor in the correct memory location as shown in block 209. Once either a read or write has occurred, the processor could go back to its wait loop, waiting for the processor to once again initiate communications.
Another advantage of the embodiment is that it may incorporate the ability to be reprogrammed serially as illustrated in
Printers in general have the ability to determine how much toner remains in the current replaceable consumable unit installed in the printer. One method described in U.S. Pat. No. 5,995,772, issued to Barry, et al., describes how a paddle would measure a delay as it rotated through toner contained in a toner hopper. The amount of delay experienced by the paddle is proportional to the amount of toner remaining in the cartridge. This delay is then used in a mathematical equation to determine how much toner is remaining in the toner hopper. Another way of determining toner level is a variation of the paddle. This variation would determine how long and how far the paddle is able to freely rotate from the top of its arch to the point it contacted toner within the toner hopper. Instead of a delay, as the paddle made its way through the toner, there would be a brief period of time that the drive shaft would not be moving the paddle since it is rotating freely as it falls. Another alternative means to determine how much toner remains is to measure the electrical or magnetic characteristics of the toner remaining in the hopper. The printer would measure the impedance or capacitance across the toner and then determine the appropriate amount of toner remaining accordingly.
Once a printer has determined how much toner is remaining it has to convey this information to the end user as well as keep a running log for its own purposes. One particular way a printer stores how much toner is remaining is the use of a “bucket level.” The printer stores a value associated with the amount of toner remaining in the bucket level memory location of the electronic circuit on the replaceable consumable unit. This area of memory is capable of being written to on a very limited basis. Initially, this bucket level will be “full” on a new or newly refurbished replaceable consumable unit. As toner is consumed the bucket level will be adjusted accordingly. The bucket level can only be decremented and never incremented during the operation of the replaceable consumable unit. If the bucket levels were ever to increase by a certain percentage, then the printer would detect this as an unauthorized attempt to refill the replaceable consumable unit and it will disable the particular replaceable consumable unit. Printer manufacturers have determined that most replaceable consumable units, once installed into a printer, may not be refilled during its current life cycle. Once the amount of usable toner has been determined to be “empty” by the printer, the printer will then store an “empty” bucket level value in the electronic circuit. Thereafter the printer will disable the replaceable consumable unit from operating by writing to another location in the circuit memory that is analogous to an “on/off” switch. In order for the printer to operate the location must correspond to an “on” value. Once this location has been rewritten with an “off” value the replaceable consumable unit will no longer function. The cartridge will then either be recycled or thrown away. The process of making these locations in memory unalterable is analogous to recording information on a 3½″ floppy diskette that has a write protection tab. Once the memory protection tab has been changed, the floppy becomes write protected.
In order to better understand the additional functionality that a replacement circuit may be able to offer, it is important to understand the significant parts of the replaceable consumable unit. Some of these parts in particular may be controlled by the actions of the replacement circuit.
The operation of a typical xerographic replaceable consumable unit is described in the U.S. Pat. No. 5,012,289 issued Apr. 30, 1991 to Aldrich, et al. In this patent, the process by which toner is transferred from the toner hopper to the developer roller and then to the Organic Photo Conductor (OPC) is outlined in great detail.
In
The developer roller 24 sits on an axle and is rotated by a developer roller drive gear 12. At the opposite end of the axle, the developer roller contact bushing 11 engages the developer electrical contact 10, which allows for a DC potential to be applied across the developer roller 24 providing a charge necessary to negatively charge the toner. Sufficient voltage may be required to differentially bias the toner and may allow it to become electrically charged. As a result the toner may be attracted to the appropriate locations on the OPC drum (not shown), which may contain the image to be transferred to the print media. The OPC drum may be in close proximity to the developer roller 24 when the printer cartridge 1 is fully assembled. This proximity allows the toner to migrate from the developer roller to the OPC drum. Once toner has been transferred to the OPC drum, print media will be fed into the printer and the toner will become affixed to the media during the fusing process.
Behind the developer roller is an adder roller 15. The adder roller 15 is in physical contact with the developer roller 24 and is instrumental in ensuring a good supply of toner is presented to the developer roller. The adder roller 15 also has an adder roller electrical contact 16 that allows a potential supplied by the printer to pass through the adder roller 15. The adder roller 15 provides an initial negative charge to the toner supply. Additionally, the adder roller 15 is pressed against the developer roller 24 and the friction that results contributes additional negative charge to the toner passing between the developer roller 24 and the adder roller 15. The toner may be electrically charged in a two-stage process. The adder roller 15 may provide the initial charge, and the developer roller 24 may provide the subsequent charge.
In one particular prior art toner cartridge there is no primary charge roller (PCR). Instead the PCR is resident inside the printer. The main purpose of the PCR is to reapply an even electrical charge to the OPC drum so it will wipe clean any latent images left on the drum. As the OPC rotates, a laser will etch an image on the drum creating areas of less negatively charged surfaces that correspond to the lines or shapes of the image. As the OPC rotates and comes in contact with the developer roller 24, toner will be attracted to the less negatively charged areas on the surface of the OPC. Once the toner has become affixed to the OPC, paper or other media is introduced into the printing process. The area behind the printer will also be electrically charged to the toner then migrated to the media and is melted into place.
During the printing process the voltages applied by the printer to the electrical elements of the cartridge may vary. When a higher voltage may be applied to certain components, the resulting electric charge may be greater and more toner may be attracted to the components. As a result the print image may be darker. Over the lifetime of the cartridge, the voltages may have a tendency to fluctuate and in some cases increase substantially. This may be due to the printer manufacturers intent to ensure that there is enough toner for the components to make good quality prints. It also may be a way to use toner faster thus hastening the replaceable consumable unit's toner consumption and effectively shortening the life of the cartridge.
Some printers have the ability to change the voltages being applied to these electrical components. Prior art describes changing the voltages on these components in relation to analyzing the images as they are processed off the OPC drum, which is usually done as part of a calibration procedure. Instead of basing the voltage potential on the image, a new replacement circuit could base the voltage on a specific toner level condition. This may occur when the toner in the toner hopper has reached a “toner low” state and conservation of toner is important. By returning the voltages back to their original operating states or to any level that would make the printer use less toner, the print quality could remain the same while reducing background printing. This in turn may conserve the amount of toner being used and prolong the life of the toner cartridge. In the previously discussed examples, the voltage of the PCR could be maximized (highest negative voltage) at the same time the voltage of the developer roller would be minimized (least negative voltage). The appropriate values corresponding to this change could be loaded into the replacement electronic circuit once a specific toner value had been achieved. Then the next time the printer is opened or the power is cycled, this new value may be read and the changes could then be implemented. An alternative embodiment could change the voltage of the PCR to become minimized and the voltage to the developer roller to become maximized. The voltages may be changed in numerous combinations, depending on the specific printer and the desired results.
As had been discussed previously, the original electronic circuit used for a toner cartridge may employ different communication schemes. They may be either a contact or a wireless communication platform. In particular, the wireless platforms involve the printer providing power to the electronic circuit via the RF waveforms. These circuits may be housed in a plastic casing and could be mounted on the toner cartridge. In these toner cartridges, the original electronic circuits may be mounted in an area that is form fitted for the specific casings.
An example of the prior art original electronic circuit casing 140 is further illustrated in
A variation to the embodiment in
Another embodiment of the present invention is shown in
By contrast,
In another embodiment of the present invention, the replacement electronic circuit casing may be designed to have multiple features that will facilitate removal by multiple tools. As an illustrative example, the replacement electronic circuit casing may have an indenture as well as a ledge. A tool that may fit into an indenture might be used in conjunction with another tool that may contact a ledge. These tools may be used individually, sequentially or even simultaneously with respect to each other. A replacement electronic circuit casing might have multiple indentures or multiple ledges that may be utilized by an automated process to remove the casing from the printer cartridge.
Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art appreciate that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown and that the invention has other applications in other environments. This application is intended to cover any adaptations or variations of the present invention. The following claims are in no way intended to limit the scope of the invention to the specific embodiments described herein.
This application is a continuation of U.S. patent application Ser. No. 10/701,304 filed Nov. 4, 2003 which is in turn a Continuation-In-Part of patent application Ser. No. 10/641,617 filed Aug. 15, 2003, both of which are hereby incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10701304 | Mar 2004 | US |
| Child | 11901887 | Sep 2007 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10641617 | Aug 2003 | US |
| Child | 10701304 | Mar 2004 | US |
