Abstract: An image forming apparatus includes a controller capable of executing a normal mode in which an electrostatic image formed on an image bearing member is developed by setting a peripheral velocity ratio of a developer bearing member relative to the image bearing member to a prescribed peripheral velocity ratio, and a color gamut enlargement mode in which a color gamut of an image to be formed on a recording medium is enlarged as compared to the normal mode by setting the peripheral velocity ratio of the developer bearing member relative to the image bearing member to a larger peripheral velocity ratio than the peripheral velocity ratio in the normal mode, wherein the controller identifies image color gamut information included in image data and forms an image by selecting the normal mode or the color gamut enlargement mode in accordance with the image color gamut information.

Abstract: In a first image formation mode, an image is formed with a first development contrast C1 and a specific dot pattern is formed with a second development contrast C2, which is lower than the first development contrast C1; in a second image formation mode, an image is formed with a third development contrast C3 and a specific dot pattern is formed with a fourth development contrast C4, which is lower than the third development contrast C3; and when ?C1 (=C2/C1) denotes a ratio between the second development contrast C2 and the first development contrast C1, and ?C2 (=C4/C3) denotes a ratio between the fourth development contrast C4 and the third development contrast C3, ?C2<?C1 is satisfied.

Abstract: An image heating device includes, a moving member configured to move while contacting a recording material at one surface of the moving member, a backup member configured to contact the other surface of the moving member, a holding member configured to hold the backup member, a nip portion forming member contacting the one surface of the moving member, and configured to form a nip portion in corporation with the backup member via the moving member, and a high thermal conductive member held between the holding member and the backup member, wherein the recording material on which an image has been formed is heated by heat received from the moving member while being nipped and conveyed at the nip portion, and wherein the holding member includes a recessed portion configured not to apply pressure to the high thermal conductive member.

Abstract: An image heating apparatus includes: a heater including a substrate and a heat generating element; a supporting member; a high heat-conductive member. The recording material on which an image is formed is heated by heat from the heater. The supporting member has a bottom region, where the supporting member supports the heater, including a first region where the supporting member contacts the high heat-conductive member so as to apply pressure between the heater and the high heat-conductive member and including a second region where the supporting member is recessed from the high heat-conductive member relative to the first region. At least a part of the first region overlaps, with respect to a movement direction of the recording material, with a region where the heat generating element is provided.

Abstract: A water supplying step of supplying water to a liquid-fuel channel of a nozzle is executed during a liquid fuel supply state in which only liquid fuel is supplied to the nozzle; a post-switch water purging step of supplying water to the liquid-fuel channel of the nozzle is executed during a gas fuel supply state in which only gas fuel is supplied to the nozzle; and a mid-switch water purging step of supplying water to the liquid-fuel channel of the nozzle is executed during a fuel switching state which is a state of transition from the liquid fuel supply state to the liquid fuel supply state. A second flow rate of water supplied in the mid-switch water purging step is lower than a first flow rate of water supplied in the water supplying step. In the post-switch water purging step, water is temporarily supplied at a third flow rate which is higher than the second flow rate.

Abstract: A heater used for a fixing device includes a substrate, first and second conductor patterns formed at either end of the substrate in the short direction of the substrate, a third conductor pattern formed between the first and second conductor patterns and separated from the two conductor patterns, a first heating member disposed between the first and third conductor patterns and electrically connected to the two conductor patterns, and a second heating member disposed between the second and third conductor patterns and electrically connected to the conductor patterns. The heater has both end regions in which the widths of the third conductor pattern in the short direction is smaller than that of a middle portion of the third conductor pattern. The widths of the first and second heating members in the end regions are smaller than the widths of the first and second heating members in the other region, respectively.

Abstract: A fuel control device includes a combustion temperature estimation value calculation unit that calculates a temperature estimation value when a mixture of fuel and inflow air is burned using an atmospheric condition, an opening degree command value of a valve that controls the amount of air that is mixed with the fuel and burned, and an output prediction value calculated on the basis of a fuel control signal command value used for calculation of a total fuel flow rate flowing through a plurality of fuel supply systems, a fuel distribution command value calculation unit that calculates a fuel distribution command value indicating a distribution of fuel output from the fuel supply systems based on the temperature estimation value, and outputs the fuel distribution command value, and a valve opening degree calculation unit that calculates each valve opening degree of a fuel flow rate control valve of the fuel supply systems.

Abstract: A fixing device includes: a rotatable member; a helical coil; a magnetic core; and a controller for controlling the frequency of an AC current caused to flow through the coil. The AC current is caused to flow through the coil to cause an electroconductive layer of the rotatable member to generate heat through electromagnetic induction heating, thereby heating and fixing the toner image on the recording material by heat of the rotatable member. The controller controls the frequency in a period so that when the frequency is f and a resistance of the electroconductive layer with respect to a circumferential direction is R, f/R is substantially constant.

Abstract: An image heating apparatus includes: a heater; a supporting member for supporting the heater; and a high heat-conductive sheet sandwiched between a part of the heater and the supporting member. A recording material on which an image is formed is heated by heat from the heater. The supporting member includes a bearing surface contacting the sheet so as to apply pressure between the heater and the sheet and includes an opposing portion opposing a part of the heater not sandwiching the sheet. In a state in which the pressure is applied between the heater and the sheet, the thickness of the sheet is not less than the height of the stepped portion between the bearing portion and the opposing portion.

Abstract: An image heating apparatus includes: a heater including a substrate and a heat generating element; a supporting member; a high heat-conductive member. The recording material on which an image is formed is heated by heat from the heater. The supporting member has a bottom region, where the supporting member supports the heater, including a first region where the supporting member contacts the high heat-conductive member so as to apply pressure between the heater and the high heat-conductive member and including a second region where the supporting member is recessed from the high heat-conductive member relative to the first region. At least a part of the first region overlaps, with respect to a movement direction of the recording material, with a region where the heat generating element is provided.

Abstract: An image heating apparatus includes: a heater including a substrate and a heat generating element; a supporting member; and a high heat-conductive member. The recording material on which an image is formed is heated by heat from the heater. The supporting member has a bottom region, where the supporting member supports the heater, including a first region where the supporting member contacts the high heat-conductive member so as to apply pressure between the heater and the high heat-conductive member and including a second region where the supporting member is recessed from the high heat-conductive member relative to the first region. At least a part of the first region overlaps, with respect to a movement direction of the recording material, with a region where the heat generating element is provided.

Abstract: A fixing device includes: a rotatable member; a helical coil; a magnetic core; and a controller for controlling a frequency of an AC current caused to flow through the coil. The AC current is caused to flow through the coil to cause an electroconductive layer of the rotatable member to generate heat through electromagnetic induction heating thereby to heat and fix the toner image on the recording material by heat of the rotatable member. The controller controls the frequency in a period so that when the frequency is f and a resistance of the electroconductive layer with respect to a circumferential direction is R, f/R is substantially constant.

Abstract: A fixing device includes a rotatable member having an electroconductive layer; a magnetic member which does not form a loop outside the electroconductive layer; a coil helically wound outside said magnetic member, wherein the coil forms an AC magnetic field by a flow of a current therethrough to cause the electroconductive layer to generate heat through electromagnetic induction heating; and a back-up member. When a circumferential direction resistance R of the electroconductive layer is represented by the following formula (1), a frequency f of the AC magnetic field and the circumferential direction resistance R satisfy the following formula (2): R=?×2?r/tw??(1) f/R?15 (kHz/milliohm)??(2) where with respect to the electroconductive layer, ? is a volume resistivity at a fixing temperature, t is a thickness, r is a radius, and w is a length with respect to a generatrix direction of the rotatable member.

Abstract: A heater used for a fixing device includes a substrate, first and second conductor patterns formed at either end of the substrate in the short direction of the substrate, a third conductor pattern formed between the first and second conductor patterns and separated from the two conductor patterns, a first heating member disposed between the first and third conductor patterns and electrically connected to the two conductor patterns, and a second heating member disposed between the second and third conductor patterns and electrically connected to the conductor patterns. The heater has both end regions in which the widths of the third conductor pattern in the short direction is smaller than that of a middle portion of the third conductor pattern. The widths of the first and second heating members in the end regions are smaller than the widths of the first and second heating members in the other region, respectively.

Abstract: An image heating device for heating a toner image while nip-conveying a recording material, in a nip, on which the toner image is carried, includes a heating member; and a pressing roller, including an elastic layer, for forming the nip in contact with the heating member. The elastic layer of the pressing roller includes a thermosetting silicon rubber containing a thermal conductive filler. The thermosetting silicon rubber includes pore portions formed with resin microballoons and a pore connecting portion for connecting the pore portions. The elastic layer has a thermal conductivity of 0.15 W/mK to 0.5 W/mK.

Abstract: A heater used for a fixing device includes a substrate, first and second conductor patterns formed at either end of the substrate in the short direction of the substrate, a third conductor pattern formed between the first and second conductor patterns and separated from the two conductor patterns, a first heating member disposed between the first and third conductor patterns and electrically connected to the two conductor patterns, and a second heating member disposed between the second and third conductor patterns and electrically connected to the conductor patterns. The heater has both end regions in which the widths of the third conductor pattern in the short direction is smaller than that of a middle portion of the third conductor pattern. The widths of the first and second heating members in the end regions are smaller than the widths of the first and second heating members in the other region, respectively.

Abstract: A fixing device includes a rotatable member having an electroconductive layer; a magnetic member which does not form a loop outside the electroconductive layer; a coil helically wound outside said magnetic member, wherein the coil forms an AC magnetic field by a flow of a current therethrough to cause the electroconductive layer to generate heat through electromagnetic induction heating; and a back-up member. When a circumferential direction resistance R of the electroconductive layer is represented by the following formula (1), a frequency f of the AC magnetic field and the circumferential direction resistance R satisfy the following formula (2): R=?×2?r/tw ??(1) F/R?15 (kHz/m?) ??(2) where with respect to the electroconductive layer, ? is a volume resistivity, t is a thickness, r is a radius, and w is a length with respect to a generatrix direction of the rotatable member.

Abstract: An image heating device includes, a moving member configured to move while contacting a recording material at one surface of the moving member, a backup member configured to contact the other surface of the moving member, a holding member configured to hold the backup member, a nip portion forming member contacting the one surface of the moving member, and configured to form a nip portion in corporation with the backup member via the moving member, and a high thermal conductive member held between the holding member and the backup member, wherein the recording material on which an image has been formed is heated by heat received from the moving member while being nipped and conveyed at the nip portion, and wherein the holding member includes a recessed portion configured not to apply pressure to the high thermal conductive member.

Abstract: An image heating apparatus includes: a heater including a substrate and a heat generating element; a supporting member; a high heat-conductive member. The recording material on which an image is formed is heated by heat from the heater. The supporting member has a bottom region, where the supporting member supports the heater, including a first region where the supporting member contacts the high heat-conductive member so as to apply pressure between the heater and the high heat-conductive member and including a second region where the supporting member is recessed from the high heat-conductive member relative to the first region. At least a part of the first region overlaps, with respect to a movement direction of the recording material, with a region where the heat generating element is provided.

Abstract: An image heating apparatus includes: a heater; a supporting member for supporting the heater; a high heat-conductive sheet sandwiched between a part of the heater and the supporting member. A recording material on which an image is formed is heated by heat from the heater. The supporting member includes a bearing surface contacting the sheet so as to apply pressure between the heater and the sheet and includes an opposing portion opposing a part of the heater not sandwiching the sheet. In a state in which the pressure is applied between the heater and the sheet, a thickness of the sheet is not less than a height of the stepped portion between the bearing portion and the opposing portion.