Memory storing data of a toner cartridge is provided, and control of transfer, fixing or the like is performed based on the data

An image forming apparatus includes an image forming unit configured to form an image under a control condition and including developing device; a toner cartridge configured to supply toner to the developing device; a measuring device configured to acquire measurement data; a first memory which is provided for the toner cartridge and includes a data reference destination for obtaining the control condition and a correction value of the control condition for standard data or a plurality of control data corresponding to the measurement data; a second memory configured to store the measurement data, the standard data, one of the correction value and the control data, and the obtained control condition; and a processing mechanism configured to read the standard data and the correction value, or the measurement data and the control data and to obtain the control condition.

FIELD

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

BACKGROUND

In an image forming apparatus, a memory storing data such as characteristics of each toner cartridge is provided for the toner cartridge, and control of transfer, fixing or the like is performed based on the data.

In the image forming apparatus as stated above, when a power source is turned on, or a new toner cartridge is mounted to the image forming apparatus, it is determined that there is a possibility that the toner cartridge is replaced. All data is read from a memory on a toner cartridge side, and is read into a memory on an image forming apparatus side. For example, at the time of return from a sleep mode for energy saving, or at an opening and closing of a toner cartridge, reading of all data is similarly performed.

At this time, respective components of the image forming apparatus are also started, and the data is read before completion of start-up of, for example, a fixing unit including a heat source which takes a relatively long time to start.

In a color printer of an image forming apparatus, since data is sequentially read from memories of respective toner cartridges of yellow, magenta, cyan and black, a readout time is four times longer than that of a monochrome printer. Although it is conceivable to reduce data content in order to shorten the data readout time, the reduction of the data content itself is difficult.

DETAILED DESCRIPTION

Reference will now be made in detail to the present embodiment of the invention, an example of which is illustrated in the accompanying drawing.

FIG. 1is a structural view of an image forming apparatus which is a four-tandem color printer and is an example of an image forming apparatus (MFP) of the embodiment. As shown inFIG. 1, a secondary transfer roller11to transfer an image on an intermediate transfer belt10onto a transfer medium12, and image forming units20Y,20M,20C and20K of yellow, magenta, cyan and black are arranged along a conveyance direction (arrow direction) of the intermediate transfer belt10.

The image forming units20Y,20M,20C and20K include photoreceptors21Y,21M,21C and21K as image carriers. Further, chargers22Y,22M,22C and22K as charging units, developing devices23Y,23M,23C and23K including developing rollers as developing members and containing developers including respective color toner particles of yellow, magenta, cyan and black and carrier particles, primary transfer rollers24Y,24M,24C and24K as transfer units, and cleaner units25Y,25M,25C and25K are provided around the respective photoreceptors. These are respectively arranged along rotation directions of the corresponding photoreceptors21Y,21M,21C and21K.

The respective primary transfer rollers24Y,24M,24C and24K are disposed inside the intermediate transfer belt10, and nip the intermediate transfer belt10in cooperation with the corresponding photoreceptors21Y,21M,21C and21K. Exposure devices26Y,26M,26C and26K are respectively arranged so that exposure points are formed on outer peripheral surfaces of the photoreceptors21Y,21M,21C and21K between the chargers22Y,22M,22C and22K and the developing devices23Y,23M,23C and23K. The secondary transfer roller11is arranged outside the intermediate transfer belt10so as to contact therewith.

A print operation is performed as described below by the image forming apparatus constructed as described above. A toner image of yellow formed on the photoreceptor of the image forming unit20Y is primarily transferred onto the intermediate transfer belt10. A toner image is formed in the image forming unit20Y. The same process is performed also in the image forming units20M,20C and20K in synchronization with a timing of the toner image formation in the image forming unit20Y. Toner images of magenta, cyan and black formed on the photoreceptors of the image forming units20M,20C and20K are also sequentially primarily transferred onto the intermediate transfer belt10.

The transfer medium12is conveyed from a cassette (not shown), and is sent to the intermediate transfer belt10by an aligning roller (not shown) in synchronization with the timing of the toner image on the intermediate transfer belt10.

A bias (+) having a polarity opposite to a toner charge polarity is applied to the secondary transfer roller11by a power source (not shown). As a result, the toner image on the intermediate transfer belt10is transferred onto the transfer medium12by a secondary transfer voltage applied between the intermediate transfer belt10and the secondary transfer roller11. A fixing unit (not shown) to fix the toner transferred on the transfer medium12is disposed, and a fixed image is obtained by causing the transfer medium12to pass through the fixing unit.

Incidentally, here, although the description is made on the example in which the image forming units are arranged in the order of yellow, magenta, cyan and black, the color order is not particularly limited.

FIG. 2is a schematic structural view of an image forming unit20of the image forming apparatus of the embodiment. Incidentally, the image forming units20Y,20M,20C and20K of the respective colors have the same structure.

As shown inFIG. 2, a charger22, a developing device23and a cleaner unit25are arranged around a photoreceptor21. A toner cartridge27is mounted to the developing device23. A memory28is provided to the image forming apparatus and a memory29in which control data is written is attached to the toner cartridge27.

Incidentally, the toner cartridge27may be integrated with the developing device and the like to form a developing unit. In this case, the memory29has only to be attached to the developing unit. Besides, the memory29is separated from the toner cartridge27or the like and may be separately mounted to the image forming unit.

In the image forming apparatus as stated above, readout is performed from the memory on the toner cartridge as described below, and the image forming apparatus is placed into a print operation ready state.

FIG. 3is block diagram of a structural portion in which the readout of data from the memory on a toner cartridge side is performed. As shown inFIG. 3, a CPU31as a processing mechanism of arithmetic control or the like is connected to the respective components of the image forming units20Y,20M,20C and20K such as the chargers22Y,22M,22C and22K, the memory28on the image forming apparatus side, a temperature and humidity sensor30as a measuring equipment, and a display part32to display an error or the like, and is connected to memories29K,29Y,29M and29C of toner cartridges27K,27Y,27M and27C.

FIG. 4shows a correspondence table of address and information content in the memory28of the image forming apparatus, andFIG. 5shows correspondence tables of address and information content in the memories29K,29Y,29M and29C of the toner cartridges.

As shown in the table ofFIG. 4, the memory28of the image forming apparatus includes, for each address, an area (A001) in which an identification code for identifying a machine type is inputted, areas (A002-A005) in which color codes of the image forming units20K,20Y,20M and20C are inputted, a measurement data area (A006) in which temperature and humidity data from the temperature and humidity sensor30is written, areas (A007-A010) in which toner control data from the memories29K,29Y,29M and29C, described later, are written, and areas (A011-A014) in which standard control data of the respective toners are inputted.

As shown in the table ofFIG. 5, each of the memories29Y,29M,29C and29K of the toner cartridge includes areas in which an identification code (00h), a color code (01h), a data reference destination (02h), a correction coefficient (03h) as a correction value for standard control data, and control data (04h-FFh) corresponding to temperature and humidity are inputted.

By the structure as stated above, in the image forming unit, readout of control data, such as a charge amount, is performed as described below.FIG. 6is a flowchart. As shown inFIG. 6, a power source is turned ON, or a front cover is opened and closed in order to attach a new toner cartridge (Act1).

First, readout is performed from the memory29K of the toner cartridge27K. The identification code is read from 00h of the memory29K, and it is determined whether the identification code is coincident with that of A001 of the memory28(Act 2-1). When the identification codes are coincident, the color code K is read from 01h of the memory29K, and it is determined whether the color code is coincident with the color code K of A002 (Act 2-2)

When the identification codes are not coincident, the display part32display an error to that effect (Act 6-1), and the toner cartridge is replaced, or a shift is made to a non-recognition print mode in which control data is not read (Act 6-2).

When the color codes are coincident, the reference destination of the control data is read from 02h of the memory29K (Act 2-3).

At this time, for example, with respect to the toner stored in the toner cartridge27K, when a control condition can be calculated by correcting standard data by a specified correction value independently of the temperature and humidity, the reference destination is the memory28. In this case, only correction coefficient is read from 03h of the memory29K (Act2-4). The CPU31calculates the control condition from the standard data of A011 of the memory28and the correction coefficient of 03h (Act 2-5).

On the other hand, in the toner stored in the toner cartridge27K, for example, when the correction value for calculating the control condition is changed by the temperature and humidity, the reference destination is the memory29K. In this case, all the control data of 04h-FFh are read (Act 2-6). The CPU31selects the control condition from the control data based on the temperature and humidity data previously acquired by the temperature and humidity meter30and stored in A006 (Act 2-7).

The calculated or selected control condition is stored in A007 of the memory28(Act 2-8).

When the color codes are not coincident, an error to that effect is displayed (Act 7-1), and the toner cartridge is replaced with a correct one (Act 7-2).

Similarly, readout from the memory29Y of the toner cartridge27Y, storage of the control condition (Act 3-1 to Act 3-8), readout from the memory29M of the toner cartridge27M, storage of the control condition (Act 4-1 to Act 4-8), readout from the memory29C of the toner cartridge27C, and storage of the control condition (Act 5-1 to Act 5-8) are sequentially performed.

The readout from the memories29K,29Y,29M and29C of all the toner cartridges27K,27Y,27M and27C, and the calculation of the control conditions are ended, the image forming apparatus is placed into the print operation ready state (Act 8). In the respective image forming units20K,20Y,20M and20C, the print operations under the respective control conditions stored in A007 to A010 are performed (Act 9).

In this way, the selection can be performed such that when the control condition can be corrected by the fixed correction value, only the correction value is read, and when not so, all the control data are read. Accordingly, a readout time of the unnecessary readout can be shortened.

For example, as in the related art, when all control data are read, a readout processing time in each of the toner cartridges27K,27Y,27M and27C is 1.020 seconds, and a total processing time is 4.080 seconds. On the other hand, when only the correction value is read, the readout processing time of each is 0.060 seconds, and the total processing time is 0.240 seconds. Accordingly, a memory content is not changed from that of the related art, and the readout time can be greatly shortened. The data readout time can be shortened not only in full-color printing but also in monochrome or monocolor printing.

In this embodiment, although the control condition is a charging output and a development bias, and the measurement data is the temperature and humidity, no limitation is made to this. For example, the control condition may be a laser output, and the measurement data may be the temperature and humidity. Besides, the control data is made a correction value for the standard data dependent on the measurement data, and the control condition may be calculated by the correction value selected based on the measurement data.

Incidentally, by reading intrinsic data of the toner cartridge, such as a serial number of the toner cartridge, it can be determined whether the toner cartridge is a new toner cartridge or is not changed (the same as the toner cartridge at the last printing). When the intrinsic data is coincident with previously read intrinsic data (the same toner cartridge), the correction data is not read, and the control condition stored in A007 of the memory of each toner cartridge can be used as it is. By this, the readout time can be further shortened.