Fixing device with receiving portion configured to receive information corresponding to width of recording material from external terminal and image forming apparatus including such fixing device

A fixing device detachably mountable to an image forming apparatus, includes: a pair of rotatable members forming a nip configured to fix a toner image on a recording material by heat and pressure; a receiving portion capable of receiving information corresponding to the width of a recording material from an external terminal so as to limit a use of the fixing device; and a storing portion configured to store the information received by the receiving portion.

FIELD OF THE INVENTION AND RELATED ART

The present invention relates to a fixing device and an image forming apparatus. This fixing device is usable in, e.g., a copying machine, a printer, a facsimile machine and a multi-function machine having a plurality of functions of these machines.

In a conventional image forming apparatus of an electrophotographic type, a fixing device for fixing a toner image formed on a recording material by using an electrophotographic process is mounted. This fixing device has a constitution in which the toner image is heated while nipping and feeding the recording material at a nip formed by a pair of rotatable members, e.g., a fixing roller and a pressing roller.

The state of a surface of the fixing roller has an influence on the glossiness of an image, and therefore it has become important more than ever that the surface property of the fixing roller is stably maintained. However, when a side edge of the recording material continuously contacts the fixing roller at the same position, there is a tendency for the surface property at a portion thereof (contact portion) is inferior to that at another portion.

It would be considered that this is because the side edge of the recording material has a minutely bent (flexed) shape during the manufacturing thereof, i.e., during cutting.

In such a background, when recording materials having the same width are continuously introduced into the fixing device, fixing roller portions contacting both side edges of the recording materials are damaged (also referred to as fixing device).

In such a state that the edge damage is generated on the fixing roller surface, when the image is formed on a recording material wider than the above recording materials, there is a risk that the glossiness of the image at a portion corresponding to the edge damage is lowered compared with that at another portion, and thus uneven glossiness is generated on the image.

Therefore, in an apparatus (device) described in Japanese Laid-Open Patent Application (JP-A) 2008-040365, the generation of uneven glossiness on the image is suppressed by rubbing the fixing roller surface with a roughening roller to level out the surface property of the fixing roller with respect to a longitudinal direction of the fixing roller, and therefore this method is an excellent method that is satisfactory for a general user.

However, in the method described in JP-A 2008-040365, it is difficult to completely eliminate the uneven glossiness of the image, and in the case where the required level by the user with respect to uniformity of the glossiness of the image is very high, it is difficult to deal with the uneven glossiness by using such a method.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, there is provided a fixing device detachably mountable to an image forming apparatus, comprising: a pair of rotatable members forming a nip configured to fix a toner image on a recording material by heat and pressure; a receiving portion capable of receiving information corresponding to a width of a recording material from an external terminal so as to limit a use of the fixing device; and a storing portion configured to store the information received by the receiving portion.

According to another aspect of the present invention, there is provided an image forming apparatus comprising: an image forming device configured to form a toner image on a recording material; and a fixing device configured to fix the toner image, formed by the image forming device, on the recording material. The fixing device includes a receiving portion capable of receiving information corresponding to a width of the recording material from an external terminal and includes a storing portion configured to store the information received by the receiving portion. The image forming apparatus also includes: a reading portion configured to read the information stored in the storing portion; an obtaining portion configured to obtain information of the width of a recording material to be subjected to image formation; and a controller configured to control whether or not an image forming operation should be prohibited the basis of the information read by the reading portion and the information obtained by the obtaining portion.

DESCRIPTION OF THE EMBODIMENTS

Embodiments of the present invention will be described, but although the following embodiments are examples of preferred embodiments, the present invention is not limited to the following embodiments.

General Structure of Image Forming Apparatus

FIG. 2is a schematic view showing a general structure of an image forming apparatus1in this embodiment. This image forming apparatus1is an electrophotographic full-color printer which is of an intermediary transfer type and which has a both-side image forming function. Inside an apparatus main assembly (image forming apparatus main assembly)1A of the image forming apparatus1, e.g., four image forming portions2Y,2M,2C and2K corresponding to Y (yellow), M (magenta), C (cyan) and K (black), respectively, are disposed in series as an image forming means. That is, as the image forming device, a tandem type is employed in which a process is performed in parallel among the respective colors of Y, M, C and K until a visible image is formed.

In order to avoid a cumbersome description, the four image forming portions2Y,2M,2C, and2K, for the respective colors of Y, M, C and K, will be described by representing these portions with the reference numeral “2”, and this schema of using a reference numeral instead of a reference numeral and a letter is similarly applied to the following associated process means, such as the photosensitive members3Y,3M,3C, and3K, the primary chargers4Y4M,4C, and4K, the exposure devices5Y,5M,5C, and5K, the developing devices6Y,6M,6C, and6K, and the cleaning device7Y,7M,7C and7K so that these devices are respectively referred to with reference numerals3,4,5,6, and7. Further, the order of arrangement of the image forming portions2for the respective colors of Y, M, C and K is not limited to the above order.

At each of the image forming portions2, the following respective electrophotographic process means are provided. That is, a photosensitive member (image bearing member)3for bearing an electrostatic latent image on a surface thereof corresponding to an associated one of the colors of Y, M, C and K, a primary charger4, an exposure device5, a developing device6and a cleaning device7are provided.

The primary charger4electrically charges the surface of an associated photosensitive member3uniformly by applying a charging bias voltage having a set potential. The surface of the photosensitive member3is exposed to light by the exposure device5corresponding to an image information pattern, so that the electrostatic latent image is formed. The electrostatic latent image is developed with a toner (developer) by the developing device6, thus being changed into a visible image as a toner image.

Toner images of the respective colors of Y, M, C and K, which are formed and carried on the surfaces of the photosensitive members3of the respective image forming portions2, are successively primary-transferred superposedly onto an endless belt as an intermediary transfer member9by a primary transfer device8. A primary transfer residual toner on each of the photosensitive members3is removed by the cleaning device7.

An unfixed full-color toner image formed on the intermediary transfer member9by superposing the toner images of all the colors of Y, M, C and K is collectively secondary-transferred by a secondary transfer device10onto a recording material P as a recording medium fed from a feeding portion11to the secondary transfer device10.

The recording material (hereinafter referred to as a sheet) P is an image formable sheet-like member and may include plain paper, glossy paper, a resin-made sheet such as an OHP sheet, thick paper, an envelope, a postcard, a label or the like. In the image forming apparatus1in this embodiment, the feeding portion11includes sheet cassettes12and13as upper and lower cassette portions, each accommodating sheets P. Further, a feeding member for the sheet cassette accommodating sheets P, having a width selected and designated in advance, is driven, so that one of the sheets P in the cassette is separated and fed to the secondary transfer device10through a feeding path a.

The width of the sheet P is a sheet dimension with respect to a direction perpendicular to a sheet feeding direction X (FIG. 1) on a sheet surface. In the image forming apparatus1in this embodiment, independently of the width of the sheet P, the sheet P is introduced into a fixing device (fixing unit)100so that a center position of the sheet P with respect to a width direction of the sheet P substantially coincides with a center position of the fixing device100with respect to the width direction of the fixing device100.

The sheet P that has passed through the secondary transfer device10is separated from the intermediary transfer member9and is guided by a feeding device14into the fixing device100functioning as an image heating apparatus. The fixing device100applies heat and pressure to the unfixed toner image while nipping and feeding the sheet P, thus fixing the toner image as a fixed image as described later.

In the case of a one-side image forming mode, the sheet P coming out of the fixing device100is changed in course to a feeding path b side by a flag15, and is discharged, as a full-color image-formed product (resultant product) on which the image is formed on one surface thereof, onto a discharging tray17.

In the case of a double-side image forming mode, the sheet P which comes out of the fixing device100and on which the image has already been formed on a first surface is changed in course to a double-side feeding path mechanism18side by the flag15. Then, the sheet P is fed in a switch-back manner after being fed into a feeding path c of the mechanism18, and is fed again into the feeding path a via a feeding path d in an upside-down state, thus being fed to the secondary transfer device10. As a result, the secondary transfer of the toner image from the intermediary transfer member9onto a second surface of the sheet P is made.

Therefore, similarly as in the case of the one-side image forming mode, the sheet P is fed through a course in the order of the feeding device14, the fixing device100, the feeding path b and a discharging roller pair16, and is discharged, as a full-color image-formed product (resultant product) on which the image is formed on both (first and second) surfaces, onto the discharging tray17by the discharging roller pair16.

FIG. 1is an enlarged schematic view of the fixing device100in the image forming apparatus1inFIG. 2. The fixing device100is detachably mounted as a fixing unit in a mounting portion (fixing device mounting portion)50of the apparatus main assembly1A of the image forming apparatus1in a predetermined manner (procedure). In a state, in which the fixing device100is mounted so as to be positioned and fixed to the mounting portion50of the apparatus main assembly1A of the image forming apparatus1in a predetermined manner, the fixing device is electrically and mechanically connected with a controller, an electric power supplying portion, a driving mechanism portion and the like in the apparatus main assembly1A side in a predetermined manner, thus receiving supplied electric power and a driving force from the apparatus main assembly1A side.

The fixing device100includes a fixing roller (fixing member)101and a pressing roller (opposite member, pressing member)102, are a pair of rotatable members for forming a nip (fixing nip) N where the sheet P carrying thereon an unfixed toner image K is nipped and fed. Further, the fixing device100includes, as an external heating means, an external heating belt105rotatably stretched by first and second supporting rollers103and104. Further, the fixing device100includes a web cleaning device for cleaning the surface of the fixing roller101.

The fixing roller101is prepared by forming a parting layer of a heat-resistant resin material on an outer peripheral surface of a metal core and is rotationally driven in the clockwise direction of an arrow A at a predetermined peripheral speed by a driving motor (driving mechanism)108controlled with respect to a rotational speed by a drive control means (motor controller)109. Inside the metal core of the fixing roller101, a halogen heater111as an internal heat generating element is provided, and heats the fixing roller10in combination with the external heating belt105so that the surface temperature of the fixing roller101is a predetermined temperature.

The pressing roller102is prepared by forming a heat-resistant elastic layer on an outer peripheral surface of a metal core, and is disposed in parallel to the fixing roller101. Further, by an unshown pressing means, the pressing roller102is pressed toward the fixing roller101at a predetermined pressure against the elasticity of the elastic layer, so that the fixing nip N having a predetermined width with respect to the feeding direction X of the sheet P is formed between itself and the fixing roller101.

The pressing roller102is rotated by the rotational drive of the fixing roller101in the counterclockwise direction of an arrow B at a peripheral speed corresponding to the peripheral speed of the fixing roller101. Inside the metal core of the pressing roller102, a halogen heater112as the heat generating element is provided, so that the pressing roller102is heated from an inside thereof so that the surface temperature of the pressing roller102is a predetermined temperature.

The surface temperature of the fixing roller101is detected by a thermistor121as a temperature detecting means contacting the fixing roller101. The surface temperature of the pressing roller102is detected by a thermistor122contacting the pressing roller102. Electrical signals relating to the temperatures outputted from the thermistors121and122are once collected by a fixing device substrate (electrostatic circuit substrate)107provided in the fixing device100, and thereafter are inputted into a heater control means106functioning as a temperature control (adjusting) means.

The heater control means106turns on and off the respective halogen heaters111and112on the basis of detected temperatures of the thermistors121and122, respectively, so that the heater control means106controls the heaters so that each of the surface temperature of the fixing roller101and the surface temperature of the pressing roller102is the predetermined temperature.

The fixing device substrate107also has the following functions in addition to the temperature detection of the thermistors121and122. That is, the fixing device substrate107also has the function of controlling driving of a motor for operating an unshown pressing means for moving the pressing roller102toward and away from the fixing roller101and the function of collecting signal lines and power lines which are used for operating a sensor for detecting positions (pressing state position and pressing-eliminated state position) of the pressing means.

The rotational driving of the fixing roller101and the following rotation of the pressing roller102with the rotational driving of the fixing roller101are performed, and the surface temperatures of both of the rollers are increased up to the predetermined temperatures, so that temperature control is performed. In this fixing device state, the sheet P, which passed through the secondary transfer device10and which is fed into the fixing device100by the feeding device14, is guided by a guiding member110into the nip N, and is nipped and fed. A carrying surface of the sheet P, which is to be guided into the nip N and which carries the unfixed toner image K, is directed upward, and faces the fixing roller101.

In this way, by nipping and feeding the sheet P through the nip N, the unfixed toner image K is fixed as the fixed image on the surface of the sheet (recording material) P under application of heat and pressure. The sheet P coming-out of the nip N is separated from the fixing roller101and the pressing roller102, and is sent from the inside of the fixing device100by a discharging roller pair113for the fixing device100. The web cleaning device wipes and removes offset toner on the surface of the fixing roller101. The external heating means (103,104,105) is provided upstream of the nip N and downstream of the web cleaning device114with respect to the fixing roller rotational direction.

As described above, the fixing device (fixing unit)100includes the fixing portions101and102for fixing the toner image formed on the sheet.

Further, in this embodiment, on the substrate107of the fixing device100, a holding portion117for holding information (information relating to an operating condition) for limiting use of the fixing device100is mounted. In this embodiment, this holding portion117is a nonvolatile memory (storing portion) represented by ROM, RAM, flash memory, or the like.

Specifically, the above information is information corresponding to a specific width of the recording material capable of being introduced into the fixing device, and the information is stored (held) in a size storing region703of the memory117. That is, in the size storing region703, for a user who requires a high level of uniformity in glossiness of the image, specific width information of the recording material, depending on the user's demand (requirement), is stored. This specific width is a dimension of the recording material with respect to a direction perpendicular to the feeding direction X and is hereinafter referred to as an exclusive width. That is, for such a user, in principle, it becomes possible to provide a fixing device exclusively for the recording material having the specific width.

Accordingly, the fixing device mounted in the image forming apparatus1can be replaced with the fixing device for the width of the specific recording material to be subjected to the image formation. That is, the user possesses a plurality of fixing devices (to which the specifications are common) at the same time.

Further, on these fixing devices100, at a position which is readily recognized by the user (operator), a discriminating member130, having a visible label (writing) indicating a specific width (W) corresponding to information stored in the memory117, also be provided.

Further, writing of the above information into the memory117may also be performed through a display portion (touch panel)701A described later. In this case, the writing of the above information into the memory117may only be required to be performed after the fixing device mounted in the image forming apparatus is replaced with an unused fixing device100and before the image formation is effected.

In the case where the user or the operator intends to completely avoid generation of uneven glossiness of the image due to edge damage, which can occur on the surface of the fixing roller101, from the plurality of these fixing devices100, the fixing device100for the sheet (exclusive width setting) having the specific width in order to limit the use of the fixing device is selected.

The selection can be made after seeing the label (writing) of the discriminating member130. Then, the selected fixing device100can be used after the mounted fixing device100is exchanged (replaced) with the selected fixing device100and is mounted in the mounting portion50of the apparatus main assembly1A. As a result, it becomes possible to reliably prevent the generation of an image defect due to the edge damage.

FIG. 3is a block diagram of an outline of a control system of the image forming apparatus1. A general printing operation (image forming operation) of an image forming process mechanism702of the image forming apparatus1is controlled by a central controller700controlled by a CPU.

An operating portion (operating panel)701functions as an inputting means, for inputting various pieces of information, such as a recording material size inputting means. The operating portion701includes a display portion (information display portion)701A and an operating button portion701B as shown inFIG. 5. At the operating button portion701B, various settings of the printing operation performed by the image forming apparatus1are inputted. The display portion701A is a liquid crystal screen of a touch panel type, and at the display portion701A, not only is information display of various messages or the like performed, but also display of various operation buttons (keys) is performed. Also by the displayed operation buttons, the various settings of the printing operation performed by the image forming apparatus1are inputted.

The fixing device substrate107is in an electrically connected state with the controller700of the apparatus main assembly1A side in a state in which the fixing device100is mounted in the mounting portion50of the apparatus main assembly1in a predetermined manner. Further, an information reading function portion (reading portion, obtaining portion)700A of the controller700can read stored information from the memory (storing portion)117of the fixing device substrate107. In this embodiment, the information is stored (held) in the size storing region703of the memory117in advance. That is, as information relating to an operating condition of the fixing device, it is possible to read information corresponding to the specific width of the sheet to be subjected to the image formation.

FIG. 4is a flowchart of the control effected by the controller700in the case where a print job is inputted. When the user starts an inputting operation of the print job contents through the operating portion701(S1), the information reading function portion700A of the controller700detects (recognizes) the exclusive width W of the sheet stored in the size storing region703of the fixing device substrate107of the fixing device100currently mounted in the mounting portion50of the apparatus main assembly1A (S2). This detection of the exclusive width W can also be performed when a (main) power switch SW (FIG. 3) of the image forming apparatus1is turned on.

The controller700can also have a program constituted so that exclusive width information of the fixing device100detected by the information reading function portion700A is displayed at the display portion701A of the operating portion701.

By the user, the input of the print job contents advances, so that the basis weight, the size, the number of sheets, and the like, of the sheet P used are designated (printing setting), and thus the job is started (S3). At this time, the controller (also having the function of the obtaining portion)700makes reference to the exclusive width W detected in the step S2, and checks whether or not a width W2of the sheet P designated by the printing setting (print job contents) in the step S3coincides with the exclusive width W (S4). Then, in the case where the width W2and the exclusive width W coincide with each other, the controller700performs a printing operation in accordance with the inputted print job contents (S5), and when the job is completed, the controller700stops the printing operation (S6, S7).

On the other hand, in the case where the width W2does not coincide with the exclusive width W in the step S4, the controller700discriminates whether the width W2is larger or smaller than the exclusive width W (S8). In the case where the width W2is smaller than the exclusive width W, an error message saying “SHEET OF THIS SIZE CANNOT PASS”, as shown in (a) ofFIG. 5, is displayed at the display portion701A of the operating portion701(S9). That is, the image forming operation is prohibited, and replacement and mounting of the fixing device is prompted at the display portion701A.

After the display of the error, the controller700maintains the image forming apparatus1in a stand-by state. The user performs a replacing operation, on the basis of the above-described error message, in which the fixing device100currently mounted in the apparatus main assembly1A is exchanged with the fixing device100, for which the exclusive width W corresponding to the width W2of the sheet for use was inputted in the step S1, and then is mounted in the apparatus main assembly a1(S10). When the fixing device100is exchanged, the sequence goes back to the step S2, and the exclusive width W stored in the size storing region703of the fixing device100is detected, and then the controller700executes again the above-described control steps.

On the other hand, in the step S8, in the case where the width W2of the sheet is larger than the exclusive width W, the controller700displays a warning “IMAGE MAY DAMAGE” as shown in (b) ofFIG. 5at the display portion701A of the operating portion701(S11). Further, together with the display of this warning, selection buttons (keys) of “OK” (key for permitting the image forming operation) and “NG” (key for not permitting the image forming operation) are displayed on the display portion (touch panel)701A of the operating portion701to seek a user's determination (selection) (S12).

In the case where the user selects “OK” (input of information of permission), the controller700executes the printing operation in accordance with the print job contents inputted in the step S1(S5), and when the job is completed, the printing operation is stopped (S6, S7). On the other hand, when the user selects “NG” (input of information of non-permission), the sequence goes to the step S9, and the error message saying “SHEET OF THIS SIZE CANNOT PASS” as shown in (a) ofFIG. 5is displayed at the display portion701A of the operating portion701.

Then, the controller displays, at the display portion, a message prompting exchange to the fixing device100in which the width W, which coincides with the width W2of the sheet obtained in the step S1, is stored in the memory117. During the period (period until the replacement of the fixing device is performed), the image forming apparatus1is maintained in a stand-by state (S10).

The specific width of the sheet stored in the size storing region703, i.e., the exclusive width W, may also have a certain range, not one certain value. For example, in the case where the width of the sheet P intended to be exclusively used is W1, the width of the sheet designated by printing setting is W2, and a region width in which the image formation of the sheet P is not effected is W3(a width of a non-image forming region at each of both side portions of an image forming region with respect to the width direction of the sheet), if W1≦W2≦W1+2×W3is satisfied, even when the sheet P having the width W2designated by the printing setting is passed, there is no problem of edge damage due to the width W1of the sheet P intended to be exclusively passed, since the region corresponds to the non-image forming region of the sheet P provided by the print job. Accordingly, in discrimination in the step S4inFIG. 4, satisfaction of W1≦W2≦W1+2×W3by the width W2provided by the print job may also be used as a criterion of the discrimination that the widths coincide with each other in the step S4.

An effect of carrying out this embodiment will be described with reference toFIG. 6. In the case where sheets having the same width as the exclusive width W set for the fixing device100are passed, as shown in (a) ofFIG. 6, edge damage101acontinuously extending in a circumferential direction of the fixing roller101is generated at positions corresponding to the exclusive width W on the surface of the fixing roller101. This phenomenon is similarly generated on the surface of the pressing roller102, and therefore, a discussion thereof will be omitted. Y is a center (line)-basis feeding line (phantom line) of the sheet P.

In a state in which such edge damage101ais generated on the surface of the fixing roller101, as shown in (b) ofFIG. 6, the case where the sheet P having the width W2equal to the exclusive width W (W=W2) set for the fixing device100will be considered. In this case, the edge damage101aof the fixing roller101is positioned outside an image forming region width Pa of the sheet P. Accordingly, in an image forming region of the sheet P, an image defect due to transfer of the edge damage101aof the fixing roller101is not generated. An open (hollow) arrow represents the feeding direction of the sheet P.

Further, on the fixing roller101or the pressing roller102, the edge damage101a(102a) is generated only at the positions of the width W, and therefore there is no influence on the sheet P, having the width W2corresponding to the exclusive width W, to be passed thereafter.

InFIG. 6, (c) shows the case where the width W2of the sheet P designated by the printing setting is larger than the exclusive width W set for the fixing device100(W<W2). In this case, in the image forming region of the sheet P, there is a possibility that an image defect101bdue to transfer of the edge damage101ais generated at positions corresponding to the exclusive width W on the surface of the fixing roller101. In such a case, as in the step S11inFIG. 4, in the case where the generation of the damage101bon the image can be permitted by obtaining confirmation by the user, passing of the sheet P having the width W2larger than the exclusive width W is permitted.

At this time, on the fixing roller101on the pressing roller102, as shown in (c) ofFIG. 6, edge damage101ccan be generated within the width W2. However, as shown in (b) ofFIG. 6, when the sheet P having the width W2corresponding to the exclusive width W (W=W2) set for the fixing device100is passed, the image defect due to the edge damage101aor101bis not generated in the image forming region Pa. For that reason, there is no influence on a desired sheet P to be passed thereafter.

Next, as shown in (d) ofFIG. 6, the case where the width W2of the sheet P designated by the printing setting is smaller than the exclusive width W (W>W2) set for the fixing device100will be considered. In this case, in the image forming region of the sheet P, the image defect due to the edge damage101ais not generated.

However, in the case where this sheet is passed, edge damage101dcan be generated at positions of the width W2on the fixing roller101or the pressing roller102. That is, when the sheet P having the width corresponding to the exclusive width W set for the fixing device100is passed thereafter, there is a possibility that the image defect due to the edge damage101dis generated at the positions of the width W2in the image forming region of the sheet P.

Therefore, in this embodiment, in the case where the width W2of the sheet P designated by the printing setting is smaller than the exclusive width W (W>W2) set for the fixing device100, the error is displayed as in the step S9ofFIG. 4, so that execution of the print job is prohibited.

As described above, a plurality of fixing devices100having setting of the exclusive width for each of sizes (widths) of the sheets P used in the image forming apparatus1are prepared. Then, the exclusive width set for the fixing device100mounted in the image forming apparatus1is recognized, and control is made so that only the sheet having the width corresponding to the exclusive width W can pass through the fixing device100.

As a result, it is possible to prevent passing of the sheet, having the width other than the width corresponding to the exclusive width set for the fixing device100, caused by an error in fixing device100to be replaced and mounted in the apparatus main assembly1A or by an erroneous operation of the user. For that reason, it is possible to prevent the generation of the image defect due to the edge damage, on the surface of the fixing roller101, within the image forming region Pa of the sheet P.

Further, in the case where the width W2of the sheet P designated in the printing setting by the user is larger than the exclusive width W (W<W2) set for the fixing device100, the warning that there is a possibility of the generation of damage on the image is made and then a determination of the user is sought. For example, in the case where such a resultant product that image damage is not conspicuous or the user does not worry about the image damage is intended to be outputted, it becomes possible to effect the sheet passing without exchanging the fixing device100. Accordingly, it becomes possible to execute such printing with no waiting time.

Incidentally, e.g., in the case where plain paper low in glossiness is used as the sheet P and a text document is printed, even when the edge damage is generated on the fixing roller101, the image defect due to the edge damage is hardly recognizable on the fixed image. For this reason, in the case where the size information is not stored in the size storing region703, it is also possible to pass the sheets P having all the widths through the fixing device100.

The constitution of the image forming apparatus1described above is summarized as follows. The image forming apparatus1includes the image forming apparatus main assembly1A including the fixing device mounting portion50and includes the fixing device100detachably mountable to the fixing device mounting portion50. Further, the image forming apparatus1includes the holding (storing) means117, provided in the fixing device100, capable of holding (storing) the information relating to the operating condition of the fixing device by setting or setting change of the information. Further, the image forming apparatus1includes the discriminating means700A for discriminating the information held in the holding means117in the state in which the fixing device100is mounted in the fixing device mounting portion50, and includes the controller700for controlling the image forming operation of the image forming apparatus on the basis of a discrimination result of the discriminating means700A.

The information is a size of the sheet capable of being introduced into the fixing device. The holding portion117is a memory.

(Setting Method of Sheet Size Information)

Next, a method of setting sheet size information or changing the setting (of the sheet size information) in the size storing region703of the memory117as the holding portion (storing portion) provided in the fixing device100will be described.

In a state in which the fixing device100is mounted in the image forming apparatus1, in the case where the sheet size information is set in the memory117or the setting is changed, the setting or the setting change can be made using the operating portion701.

That is, the operating portion701is controlled by the controller so that a sheet width setting screen can be displayed as shown inFIG. 7by a screen selecting operation at the display portion701A of the operating portion701. Then, by using this screen, it becomes possible to set the exclusive width or change the setting of the exclusive width, through the operating portion701, in the size storing region703of the memory117in the fixing device100mounted in the mounting portion50of the apparatus main assembly1A.

In the sheet width setting screen, a button of, e.g., “A4/A3 width (297 mm)” size is pushed, and then a button of “SET” is pushed. As a result, a set value of the A4/A3 width (297 mm) size as the exclusive width is written by the controller700in the size storing region703of the memory117of the fixing device100currently mounted in the apparatus main assembly1A.

By this writing, the fixing device100is discriminated, in the state in which the fixing device100is mounted in the mounting portion50of the apparatus main assembly1A, as a fixing device exclusively used for the A4/A3 width by the discriminating means700A of the controller700. The sheet size information written in the size storing region703is written data, and therefore is retained even when the fixing device100is demounted from the apparatus main assembly1A.

Further, at a lower portion of the sheet width setting screen, a button of “CLEAR SETTING (OF SHEET WIDTH)” is displayed in parallel to other buttons, and therefore when this setting is made, the value of the size storing region703is cleaned to be returned to a value in a state of factory shipment.

As described above, the image forming apparatus includes the operating portion701where an operator is capable of inputting information for limiting the width of the recording material subjected to the image formation. Further, the image forming apparatus includes an updating portion (CPU)700for updating the information stored in the storing portion117depending on the information inputted through the operating portion701. As described above, the size storing region of the memory117of the fixing device100is set as a data storing region in which data is arbitrarily set changeably through the operating portion701by the user.

On the other hand, the change in exclusive width setting for the fixing device100can cause a problem of the image defect due to the edge damage when the change is not made simultaneously with the exchange of the fixing device with a new one. For that reason, the change in exclusive width setting is required to be made before the new fixing device is mounted in the apparatus main assembly1A of the image forming apparatus1.

The exclusive width setting in this case was made through, e.g., wireless communication. The fixing device substrate107in this embodiment includes, as shown inFIG. 1, a battery (accumulator)119and a communication module (receiving portion)118of a Bluetooth (registered trademark). For the exclusive width setting, a portable (mobile) information terminal (external terminal)800(FIG. 3) in which an exclusive managing software is installed is used. On an operating screen800A of the portable information terminal800, a setting screen similar to the sheet width setting screen (FIG. 7) displayed at the display portion701A of the operating portion701of the image forming apparatus1is displayed, and writing of sheet size information set in the size storing region703through the wireless communication is made.

The constitution of the above-mentioned fixing unit (fixing device)100is summarized as follows. The fixing unit100is detachably mountable to the image forming apparatus. The fixing unit100includes the fixing portions101and102for fixing the toner image, formed on the recording material, when the fixing unit100is mounted in the image forming apparatus, and includes the rotating portion118capable of rotating signals from the external terminal800when the fixing unit100is demounted from the image forming apparatus. Further, the fixing unit100includes the storing portion117for storing the information, readable by the image forming apparatus, for limiting the width of the recording material to be fixed depending on the signal received by the receiving portion118.

Further, the fixing unit100includes the accumulator119for driving the receiving portion118and the storing portion117when the fixing unit100is demounted from the image forming apparatus. The receiving portion118is capable of receiving wireless signals sent from the external terminal118.

Incidentally, in the case where setting or rewriting of the sheet size information for the fixing device100is made in the above-described manner, for writing of the discriminating member130(FIG. 1), it is preferable that an operation for providing writing corresponding to the set or rewritten sheet size information is performed.

The sheet size information written in the size storing region703is read by the information reading function portion700A of the controller700in the case where the power switch SW of the image forming apparatus1in which the fixing device100is mounted is turned on. Or, the sheet size information is read by the information reading function portion700A when an inputting operation of the print job contents is started by the user. Further, the sheet size information is read by the information reading function portion700A in the case where the fixing device100is demounted from the image forming apparatus1and then is mounted again in the image forming apparatus1for maintenance or the like. That is, the image forming apparatus includes the reading portion700A for reading the information stored in the above-mentioned storing portion117of the fixing device100.

FIG. 8is an illustration showing a sheet size selection screen when the fixing device100for which the exclusive width is set is mounted in the mounting portion50of the apparatus main assembly1A. In an example ofFIG. 8, the case where the fixing device100for which the A4/A3 width (297 mm) size is set is mounted is shown. The exclusive width for the fixing device100is set at the A4/A3 width (297 mm), and therefore selection of a part of the sheet sizes is disabled. That is, in the screen in which the size of the sheet P set in the image forming apparatus1is selected, buttons for setting sizes smaller in sheet width than 297 mm are greyed out, so that the screen is controlled by the controller so that these buttons cannot be selected.

That is, the image forming apparatus includes a limiting portion (CPU)700for limiting the width, of the recording material to be subjected to the image formation, depending on the information read by the reading portion700A. In this way, in the case where the plurality of the fixing devices100different in exclusive width setting are used in the image forming apparatus1in a replacing manner, control corresponding to the set sheet size is effected, so that it is possible to prevent transfer of the edge damage onto the fixed image with reliability.

Or, in the case the fixing device100is replaced with a fixing device in another image forming apparatus1and then is used, control corresponding to the set sheet size is effected, so that it is possible to prevent transfer of the edge damage onto the fixed image with reliability.

In the state in which the fixing device100is demounted from the image forming apparatus1, the sheet size setting can be rewritten, and therefore the user can make flexible setting change so as to meet user's needs of use.

In this embodiment, the wireless communication system used for setting or setting change of the exclusive width for the fixing device100is an example. As shown in (a) ofFIG. 9, a constitution in which an IC tag (RFID)801which does not require the battery119is provided on the fixing device substrate107and in which writing (rewriting) of recorded exclusive width setting is made may also be employed. Further, as shown in (b) ofFIG. 9, a constitution in which a connector802of a USB type or the like is provided on the fixing device substrate107and electric power is supplied from the portable information terminal (external terminal)800connected via a line (cable) with the connector800and in which writing (rewriting) of the exclusive width setting recorded in the memory117is made may also be employed.

As described above, in the image forming apparatus in this embodiment of the type in which the fixing device is replaced, the memory is mounted in the fixing device in order to limit the sheet size introduced into the fixing device. Then, in a stage before the fixing device is mounted in the image forming apparatus, it is possible to limit a use of the fixing device by using the external terminal. Accordingly, a user possessing a plurality of fixing devices to which the specifications are common can impose limitation of use no a desired sheet size at convenient timing. That is, flexible operation is enabled correspondingly to the user's needs, and it becomes possible to prevent the generation of the image defect with reliability.

As described above, the above-mentioned Embodiments were described as applied embodiments of the present invention, but various constitutions can be replaced with other known constitutions within the scope of the concept of the present invention.

For example, the image forming apparatus is not limited to the color image forming apparatus, but may also be a monochromatic (single color) image forming apparatus for a monochromatic image or the like.

For example, the fixing device100is not limited to a device for heating and fixing the unfixed image formed on the recording material. Also a device used in a process for adjusting a surface glossiness of an image by re-heating the toner image which has already been partly fixed or fully fixed (also in this case, the device will be referred to as the fixing device) is embraced in the fixing device100.

For example, the fixing device100can also have a device constitution using an endless belt having flexibility as either one or both of the fixing member101and the opposite member102. The opposite member102can also have a device constitution in which a non-rotatable member, such as a pad member or a plate-like member, having a slidable surface which is low in coefficient of friction with the fixing member101or the recording material P.

Further, the heating mechanism for the fixing member101and the opposite member102is not limited to the halogen heater. The heating mechanism can also have a constitution employing other appropriate heating mechanisms such as a ceramic heater type or an electromagnetic induction heating type.

This application claims the benefit of Japanese Patent Applications Nos. 2014-111045 filed on May 29, 2014 and 2015-076665 filed on Apr. 3, 2015, which are hereby incorporated by reference herein in its entirety.