Image forming apparatus and genuine product determining method for toner cartridge

An image forming apparatus includes: a loading unit on which a toner cartridge is loaded, the toner cartridge having a first storage unit in which first information indicating at least a date of manufacture of toner is stored; an image forming unit which forms an image on a sheet; a counting unit which counts time; and a determination unit which determines whether the toner cartridge is a genuine product or not, based on how large a difference is between the first information and second information specified on the basis of a count result from the counting unit.

FIELD

Embodiments described herein relate generally to an image forming apparatus and the like.

BACKGROUND

Conventionally, a toner cartridge loaded in an image forming apparatus such as electrographic apparatus has an IC chip. In the IC chip, necessary data for control to prevent reduction in performance of the image forming apparatus and information for managing the toner cartridge are stored.

This information is performance information proper to disposables such as toner cartridge. It is extremely difficult for manufacturers of non-genuine products to produce the correct information. Consequently, in some cases, an IC chip as a genuine product is directly duplicated or altered and attached to other disposables such as toner cartridge and then distributed in the market with incorrect information written in the product. Users suffer disadvantages such as deterioration in image quality by continuing the use of non-genuine products by mistake. Moreover, there is a risk that the encroachment by the non-genuine products may impair the benefit to the genuine product manufacturer.

DETAILED DESCRIPTION

According to an embodiment, an image forming apparatus includes: a loading unit on which a toner cartridge is loaded, the toner cartridge having a first storage unit in which first information indicating at least a date of manufacture of toner is stored; an image forming unit which forms an image on a sheet; a counting unit which counts time; and a determination unit which determines whether the toner cartridge is a genuine product or not, based on how large a difference is between the first information and second information specified on the basis of a count result from the counting unit.

First Embodiment

FIG. 1is a longitudinal sectional view of an image forming apparatus. However, some functional blocks are indicated by dotted lines.FIG. 2is a perspective view of a loading unit which a toner cartridge is loaded on and unloaded from, and the toner cartridge. The arrows indicate the correspondence at the time of loading.FIG. 3is a block diagram of the image forming apparatus.

An image forming apparatus1has an image reading unit R and an image forming unit P. The image reading unit R scans and reads an image of a sheet document. The image forming unit P forms a developer image on a sheet based on image data of the image read by the image reading unit R. The image reading unit R has an automatic document feeder69which automatically carries a document to a predetermined image reading position. A scanning optical system70reads an image of a document placed on a document tray Rt.

The image forming unit P has pickup rollers51to54, toner cartridges10Y to10K, photoconductive drums20Y to20K, developing devices50Y to50K, and a display unit90.

The image forming apparatus1has an apparatus storage unit17as a second storage unit, a timer18as a counting unit, and a control unit19. In the apparatus storage unit17, various programs which are executed in the image forming apparatus1are stored. The apparatus storage unit17may be a RAM (random access memory), ROM (read only memory), DRAM (dynamic random access memory), or SRAM (static random access memory). The control unit19controls various operations carried out in the image forming apparatus1. The control unit19may be an MPU or CPU and may include any number of MPUs and CPUs. The control unit19may also be an ASIC circuit which executes, in a circuit-based manner, at least a part of processing realized by the MPU and CPU. The timer18counts the current time. The timer18may also be installed inside the control unit19.

The pickup rollers51to54supply a sheet picked up from a cassette, to a sheet carrying path. A laser unit40forms an electrostatic latent image on each of the photoconductive drums20Y to20K based on image data of an image read from a document by the image reading unit R. In the toner cartridges10Y to10K, developers corresponding to yellow (Y), magenta (M), cyan (C) and black (K) are housed. The developing devices50Y to50K supply the developers to the photoconductive drums20Y to20K on which the electrostatic latent images are located. The developer images located on the photoconductive drums20Y to20K are transferred to a belt surface of an intermediate transfer belt. The developer images on the intermediate transfer belt21are transferred onto the carried sheet at a secondary transfer position T. The developer images transferred to the sheet are fixed by being heated by a fixing unit67. The sheet to which the developer images are fixed is discharged from a discharge tray68.

The toner cartridge10Y is detachably loaded on a loading unit1Ya in the image forming apparatus1. InFIG. 1, the loading unit1Ya is indicated by dotted lines. A carrying screw11Y slices the toner housed in the toner cartridge10Y and carries the toner to the developing device50Y. The carrying screw11Y is driven by a screw motor, not shown. The driving force from the screw motor is transmitted to the carrying screw11Y via a main-body-side transmission gear17Y and a cartridge-side transmission gear16Y. The control unit19controls the driving of the screw motor.

The toner cartridges10M to10K are respectively loaded on the loading units1Ma to1Ka in the image forming apparatus1. InFIG. 1, the loading units1Ma to1Ka are indicated by dotted lines. The configuration of the toner cartridges10M to10K is similar to the configuration of the toner cartridge10Y and therefore will not be described further in detail. The configuration of the loading units1Ma to1Ka is similar to the configuration of the loading unit1Ya and therefore will not be described further in detail.

The toner cartridge10Y has a cylindrical part101Y at the center in the direction of diameter. The cylindrical part101Y is located at one end in the longitudinal direction of the toner cartridge10Y. The cylindrical part101Y has cut-outs102Y at predetermined intervals at plural positions in the circumferential direction. A number of rotations detecting unit13Y is located in an area on the inner side of the cylindrical part101Y in the direction of diameter and is fixed to the loading unit1Ya. The number of rotations detecting unit13Y may be a photo-interrupter. The number of rotations detecting unit13Y has a light emitting element and a light receiving element. The number of rotations detecting unit13Y detects a light receiving state where light emitted from the light emitting element and passed through the cut-out102Y of the cylindrical part101Y is received by the light receiving element, and a non-light receiving state where light emitted from the light emitting element is interrupted by the wall part of the cylindrical part101Y and light reception by the light receiving element is prohibited. Thus, the number of rotations detecting unit13Y detects the number of rotations of the screw motor. The control unit19is electrically connected with the number of rotations detecting unit13Y and stores the number of rotations detected by the number of rotations detecting unit13Y into an IC chip14Y of the toner cartridge10Y.

The toner cartridge10Y has a chip fixing part10Ya at one end face in the longitudinal direction. The IC chip14Y is fixed to the chip fixing part10Ya and thus integrated with the toner cartridge10Y. The IC chip14Y may be a RAM (random access memory). History information of toner is stored in the IC chip14Y. The history information may include a manufacturing plant code, manufacturing lot code and classification code as well as the date of manufacture of the toner cartridge10Y. The IC chip14Y is attached to the chip fixing part10Ya when the toner cartridge10Y is manufactured. The loading unit1Ya has a chip terminal part4Y. The chip terminal part4Y has plural springs4Ya. In the state where the toner cartridge10Y is loaded on the loading unit1Ya, the these springs4Ya are pressurized and contact terminal pads101Ya of the chip fixing part10Ya. The IC chip14Y is located in an area which avoids the terminal pads101Ya of the chip fixing part10Ya.

When the screw motor stops rotating, the control unit19updates the number of rotations stored in the IC chip14Y. That is, the total number of rotations of the screw motor after the toner cartridge lay is loaded in the image forming apparatus1is stored in the IC chip14Y. Therefore, when the screw motor does not rotate, the control unit19does not update the total number of rotations stored in the IC chip14Y.

The developing device50Y is a magnetic brush-type and has a developing container501Y, a developing roller502Y, a mixer503Y, and a toner concentration sensor504Y as a second sensor. The developing devices50M to50K have a similar configuration to the configuration of the developing device50Y and therefore will not be described further in detail. The mixer503Y stirs the developer. The developer is made of toner and carrier for yellow. The toner may contain resin and carbon. The carrier includes ferrite and a coating layer formed on the surface of the ferrite. Since there is the coating layer on the surface of the ferrite, the triboelectric effect of the carrier and the toner becomes stable.

As the mixer503Y stirs the developer, a frictional force is generated between the toner and the carrier. The carrier is positively charged and the toner is negatively charged. The developing roller502Y has a magnet and its magnetic force attracts the developer, thereby forming a magnetic brush. As this magnetic brush contacts the photoconductive drum20Y rotating in the direction of arrow S, the electrostatic latent image on the photoconductive drum20Y becomes developed.

The toner concentration sensor504Y detects the toner concentration based on the magnetic permeability of the developer in the developing device50Y. That is, when the carrier ratio in the developer in the developing device50Y is increased, the magnetic permeability becomes higher and the toner concentration sensor504Y has a higher output value.

Next, the function of each unit in the image forming apparatus according to this embodiment will be described with reference toFIG. 3.FIG. 3is a functional block diagram of the image forming apparatus and the toner cartridge. The following description is about the toner cartridge10Y and the description of the other toner cartridges10M to10K is omitted.

The image forming apparatus1has a determination unit30, a loading unit1Ya,1Ma,1Ca,1Ka, an image forming unit P, the timer18, and the apparatus storage unit33. The toner cartridge10Y is loaded on the loading unit1Ya.

The timer18counts the current time. In the apparatus storage unit17, plural pieces of authentication information corresponding to each time counted by the timer18are stored.

FIG. 4is an authentication code table showing an example of authentication information stored in the apparatus storage unit17. With reference toFIG. 4, the authentication information stored in the apparatus storage unit17may be the year (Christian year) in which the toner cartridge10Y is manufactured. There are plural pieces of authentication information, including not only the year when the image forming apparatus1is shipped, but also plural years preceding and following that year. For example, the authentication information of a toner cartridge manufactured in the year 2008 is “2008”, and the authentication information of a toner cartridge10Y manufactured in the year 2011 is “2011”. This authentication information may be encrypted information such that its character information can be analyzed under predetermined rules so as to specify the year. The authentication information may also be the month of manufacture or the day of manufacture of the toner cartridge10Y.

The determination unit30acquires all the authentication information that corresponds to an allowable time zone (first authentication information), from the plural pieces of authentication information stored in the apparatus storage unit17, and determines that the toner cartridge10Y is a genuine product when one of these pieces of authentication information is identical with first information stored in the toner cartridge10Y. The first information will be described later.

The allowable time zone may be a period between a determination time when the determination unit30determines whether the toner cartridge10Y is a genuine product or not (hereinafter referred to as “determination time”) and an allowable start time before that determination time. The determination time may be a power-on time when power is turned on in the image forming apparatus1. The determination time may also be a loading time when the toner cartridge10Y is loaded in the loading unit1Ya.

As the period of the allowable time zone becomes longer, the accuracy of discriminating a non-genuine product becomes lower. As the period becomes shorter, the risk of erroneously regarding a genuine product as a non-genuine product increases. Therefore, it is desirable that the allowable start time is at least in or before the previous year of the year to which the determination time belongs.

The toner cartridge10Y has a first storage unit81. The first information indicating the date of manufacture of the toner cartridge10Y is stored in the first storage unit81. The first information corresponds to the authentication information stored in the second storage unit33. That is, if the date of manufacture is the year 2008, the same information as the authentication information stored in the apparatus storage unit17, that is, “2008” is stored as the first information.

The determination unit30compares the plural pieces of authentication information stored in the apparatus storage unit17with the first information stored in the first storage unit81. When there is identical information, the determination unit30regards the year corresponding to the identical authentication information as the year of manufacture. Moreover, the determination unit30determines whether the year of manufacture belongs to the allowable time zone or not, and thus determines whether the toner cartridge10Y is a genuine product or not.

Next, the method of determining whether the toner cartridge10Y is a genuine product or not, will be described more specifically with reference to the flowchart ofFIG. 5. In ACT101, the control unit19determines whether the toner cartridge10Y is loaded on the loading unit1Ya or not. When the toner cartridge10Y is loaded on the loading unit1Ya, the control unit19goes to ACT102.

In ACT102, the control unit19specifies the current time based on the count result from the timer18and goes to ACT103. In ACT103, the control unit19acquires all the authentication information belonging to the allowable time zone from the apparatus storage unit17and goes to ACT104.

In ACT104, the control unit19acquires the first information stored in the IC chip14Y and goes to ACT105. In ACT105, the control unit19compares the authentication information belonging to the allowable time zone with the first information. When these pieces of information are identical, the control unit19returns to ACT101. When these pieces of information are not identical, the control unit19goes to ACT106.

In ACT106, the control unit19displays alert information on the display unit90. The alert information may be character information showing that the toner is not a genuine product.

Second Embodiment

An image forming apparatus according to this embodiment will be described with reference toFIG. 1,FIG. 6andFIG. 7.FIG. 6is a functional block diagram of the image forming apparatus according to this embodiment.FIG. 7is a flowchart of a correcting method to correct the length of the allowable time zone.

As the period of the allowable time zone becomes longer, the accuracy of discriminating a non-genuine product becomes lower. As the period becomes shorter, the risk of erroneously regarding a genuine product as a non-genuine product increases. Depending on the user, the toner consumption speeds of the toner cartridges10Y to10K varies. For example, if the user intensively uses monochrome print, the consumption speed of black (K) becomes relatively faster. Thus, in this embodiment, the consumption speeds of the toner cartridges10Y to10K are monitored and the length of the allowable time zone is changed according to the result of the monitoring.

The following description is about the toner cartridge10Y and the description of the other toner cartridges10M to10K is duplicate and therefore omitted. With reference toFIG. 6, a first acquisition unit34acquires speed information about the consumption speed of each amount of toner discharged from the toner cartridge10Y.

The first acquisition unit34may be realized by the number of rotations detecting unit13Y and the control unit19in cooperation with each other. In the IC chip14Y, the result of detection by the number of rotations detecting unit13Y and the date and time of loading of the toner cartridge10Y are stored.

Therefore, the control unit19divides the total amount of supplied toner discharged from the toner cartridge10Y by the elapsed time from the date and time of loading, and thus calculates the consumption speed.

With reference toFIG. 7, in ACT201, the control unit19determines whether the toner cartridge10Y is loaded on the loading unit1Ya or not. When the toner cartridge10Y is loaded on the loading unit1Ya, the control unit19goes to ACT202.

In ACT202, the control unit19specifies the current time based on the count result from the timer18and stores the current time as the date and time of loading in the IC chip14Y of the toner cartridge10Y.

In ACT203, the control unit19determines whether an inspection period is reached or not. Here, as the inspection period, a shorter time period than the typical consumption time of the toner charged in the toner cartridge10Y may be set. That is, since the inspection period is a period provided for calculating the consumption speed of the toner, the inspection period is set to have a length from which consumption trend can be grasped.

In ACT204, the control unit19reads out the result of detection by the number of rotations detecting unit13Y from the IC chip14Y and calculates the total amount of toner supplied. In ACT205, the control unit19calculates the elapsed time from the date and time of loading and calculates the consumption speed based on the elapsed time and the total amount of toner supplied.

In ACT206, the control unit19compares the consumption speed with a reference consumption speed. When the consumption speed is relatively slower, the control unit19goes to ACT207. When the consumption speed is relatively faster, the control unit19returns to ACT203. Here, the reference consumption speed may be defined as a designed value by the manufacturer based on the record of actual use, or may be inputted by the user operating the display unit90.

In ACT207, the control unit19extends the allowable time zone and updates the information stored in the apparatus storage unit17. Thus, the toner cartridge10Y, which is a genuine product, is prevented from being erroneously determined as a non-genuine product during the use of the toner cartridge10Y. Moreover, an appropriate allowable time zone according to the consumption speed of each toner is provided.

Third Embodiment

An image forming apparatus according to this embodiment will be described with reference toFIG. 1,FIG. 8and FIG.9.FIG. 8is a functional block diagram of the image forming apparatus according to this embodiment.FIG. 9is a flowchart of a determination method to determine whether the product is a genuine product or not.

When the life of a toner cartridge approaches the end, the amount of toner discharged from the toner cartridge may be reduced. In this case, the toner cartridge may be removed temporarily from the image forming apparatus and shaken and then reloaded in the image forming apparatus. This embodiment discloses a technique for preventing a toner cartridge from being erroneously determined as a non-genuine product when the toner cartridge is reloaded in the image forming apparatus.

The following description is about the toner cartridge10Y. The description of the other toner cartridges10M to10K is duplicate and therefore omitted. With reference toFIG. 8, a second acquisition unit35acquires information about the total amount of toner discharged from the toner cartridge10Y.

The second acquisition unit35may be realized by the number of rotations detecting unit13Y and the control unit19in cooperation with each other. In the IC chip14Y, the result of detection by the number of rotations detecting unit13Y is stored.

With reference toFIG. 9, in ACT301, the control unit19determines whether the toner cartridge10Y is loaded on the loading unit1Ya or not. When the toner cartridge10Y is loaded on the loading unit1Ya, the control unit19goes to ACT302.

In ACT302, the control unit19specifies the current time based on the count result from the timer18and goes to ACT303. In ACT303, the control unit19acquires all the authentication information belonging to the allowable time zone from the apparatus storage unit17and goes to ACT304.

In ACT304, the control unit19acquires the first information stored in the IC chip14Y and goes to ACT305. In ACT305, the control unit19compares the authentication information belonging to the allowable time zone with the first information. When these pieces of information are identical, the control unit19returns to ACT301. When these pieces of information are not identical, the control unit19goes to ACT306.

In ACT306, the control unit19calculates the total amount of toner supplied, based on the result of detection stored in the IC chip14Y, and goes to ACT307.

In ACT307, the control unit19determines whether the total amount of toner supplied exceeds a threshold value or not. When the total amount supplied exceeds the threshold value, the control unit19goes to ACT308. When the total amount supplied does not exceed the threshold value, the control unit19returns to ACT301. Here, the threshold value corresponds to the total amount of toner stored in the toner cartridge10Y.

In ACT308, the control unit19displays alert information on the display unit90. The alert information may be character information indicating that the toner is not a genuine product.

The invention can be carried out in various other forms without departing from the spirit or principal features of the invention. Therefore, the above embodiments are simply examples in every respect and should not be interpreted as limiting the invention. The scope of the invention is defined by the attached claims and is not limited by the specification. Moreover, all modifications, various improvements, alterations and changes that fall within the range of equivalents to the claims are considered to be within the scope of the invention.