Abstract: A test chart on which measurement images are formed is conveyed in one direction. When the measurement images pass a color sensor, they undergo pre-scanning. A color sensor accumulation time is determined for each measurement image according to the pre-scanning. The test chart is subsequently conveyed in the one direction, whereupon the conveyance direction is changed. In this way, after the color sensor has completed pre-scanning for all of the measurement images, the test chart is once again conveyed toward the color sensor. When the test chart passes the color sensor again, main scanning of the measurement images is executed.

Abstract: An image forming apparatus includes an image forming unit configured to form a measurement image on a sheet, a measurement unit configured to irradiate light on the measurement image and measure reflected light from the measurement image, a white reference plate provided to be movable to a first position and a second position, a black member provided to be movable to a third position where the black member shields light that is irradiated on the white reference plate and to a fourth position that is retracted from the third position, and a control unit configured to, in a state in which the white reference plate is at the second position and the black member is at the third position, cause the sheet, on which the measurement image has been formed, to pass between the measurement unit and the black member and cause the measurement unit to measure the measurement image.

Abstract: An image forming apparatus includes an image forming unit configured to form a measurement image on a sheet, a measurement unit configured to emit light to the measurement image, and measure light reflected from the measurement image, a selection unit configured to select one of a first mode for feeding a sheet, forming a measurement image on the sheet with the image forming unit, and measuring the measurement image on the sheet with the measurement unit, and a second mode for feeding a chart on which a measurement image has already been formed, and measuring the measurement image on the chart with the measurement unit without performing image formation with the image forming unit, and a control unit configured to control the measurement unit to perform measurement of the measurement image according to the mode selected by the selection unit.

Abstract: When an unfixed toner image is formed on a recording material, a maximum toner amount per unit area satisfies A<(??L)/30?3, where a specific gravity of a toner is ? (g/cm3), a weight-average particle size is L (?m), and the toner amount per unit area of the unfixed toner image on the recording material is A (mg/cm2), in formation of the unfixed toner image with each color toner, and the unfixed toner image is fixed so that a region where colors of chromatic toners of respective colors in the above-described images are seen in an overlaid state is 84% or more.

Abstract: An image forming apparatus includes a color toner image forming portion for forming a toner image with a color toner on a recording material; a clear toner image forming portion for forming a toner image with a clear toner on the recording material, wherein the clear toner has a melt viscosity, at a fixing temperature, higher than that of the color toner; a fixing device for fixing the toner image formed on the recording material; an obtaining portion for obtaining information on an area in which designated glossiness is partly increased, partly decreased, or partly increased and decreased; and a control device for determining the order of formation of the toner image with the color toner and the toner image with the clear toner on the recording material depending on the information obtained by the obtaining portion.

Abstract: An image forming portion of an image forming apparatus is configured to form a toner image on a recording medium such that a relationship of M???L/(30?3) is satisfied, where a volume average particle size of toner is L(?m), density of the toners is ? (g/cm3), and a maximum toner laid quantity per unit area of a single color toner image on a recording medium is M (mg/cm2). The toner image formed by the image forming portion is fixed on the recording medium by a fixing nip portion by being heated and applied a force in a direction of a plane of the recording medium.

Abstract: An image heating apparatus includes: (i) an endless belt; (ii) a driving member; (iii) a heater including: (iii-i) a substrate; (iii-ii) a resistor; (iii-iii) a first electroconductive portion electrically connected to the resistor in a widthwise end side; and (iii-iv) a second electroconductive portion electrically connected to the resistor in another widthwise end side; and (iv) a selector for selecting one of first and second electric energy supply paths. The first electric energy supply path is electrically connected to a region of the first electroconductive portion at a longitudinal central portion of the resistor and to a region of the second electroconductive portion in at the longitudinal central portion. The second electric energy supply path is electrically connected to a region of the first electroconductive portion at a longitudinal end portion of the resistor and to a region of the second electroconductive portion at another longitudinal end portion.

Abstract: An image forming apparatus includes a color toner image forming portion, a transparent toner image forming portion, a heating portion, an obtaining portion that obtains information on an area where a gloss level should partly be increased and an area where the gloss level should partly be decreased in an image, and a controller controls the color toner image forming portion and the transparent toner image forming portion to form the color toner images and a first partial transparent toner image on a recording material, controls the heating portion to heat the color toner images and the first partial transparent toner image on the recording material, controls the transparent toner image forming portion to form a second partial transparent toner image on the recording material, and controls the heating portion to heat the second partial transparent toner image on the recording material based on information obtained by the obtaining portion.

Abstract: A heater includes: a substrate; a resistor, provided obliquely on the substrate with respect to a sheet passing direction, for generating heat by electric energy supply; a pair of first electrodes which are disposed opposed to each other via the resistor and which are electrically connected with respective ends of the resistor with respect to the sheet passing direction; and a pair of second electrodes which are disposed opposed to each other via the resistor and which are electrically connected with respective ends of the resistor with respect to the sheet passing direction. One of the first electrodes and one of the second electrodes overlap with each other as seen from the sheet passing direction.

Abstract: An image forming apparatus includes control device for selectively executing a first mode in which the non-transparent toner image is formed, then the transparent toner image is formed on the sheet not yet heated, then the sheet is subjected to the heating or a second mode in which the non-transparent toner image is formed, then the transparent toner image is formed on the sheet subjected to the heating, then the sheet is subjected to the heating; and storing device for storing selection information compared with information of amount of the non-transparent toner image, wherein the selection information indicates which mode provides larger difference in glossiness of the image fixed by the fixing device between when the transparent toner image of a predetermined amount is overlaid on the non-transparent toner image of a amount to be formed on the sheet and when the transparent toner image is not overlaid.

Abstract: Temperature of a printing medium 110 is sufficiently decreased by stopping the printing medium 110 in a discharge path, conveying the printing medium at a low speed, switching a conveyance path, or the like. If the temperature of the printing medium 110 can be sufficiently decreased, the thermochromism phenomenon is suppressed. As a result, it is possible to provide an image forming apparatus capable of achieving highly accurate color matching and color stability.

Abstract: A fixing device includes a belt heating a toner image on recording material, a member slidable on the belt inner surface, a pressor pressing the belt against the member to form a recording material nip, and a projection and recess provided on a nip forming surface of the member. When pressure applied when a toner temperature of the toner image reaches a softening temperature T1 (° C.) is P1 (kgf/cm2), pressure applied when the toner temperature reaches an incipient fluidization temperature T2 (° C.) is P2 (kgf/cm2), the toner temperature when P(t)/?(t) wherein ?(t)is a toner melt viscosity (Pa·s) and P(t) is a pressure (kgf/cm2) applied with the toner melt viscosity ?(t) is maximum is T3 (° C.), and pressure applied when the toner temperature reaches T3 (° C.) is P3 (kgf/cm2), the following relationships are satisfied: 0.3<P1/(P1+P2+P3),??1) 0.3<P2/(P1+P2+P3), and??2) 0.2<P3/(P1+P2+P3)<0.3.

Abstract: When glossiness in an area designated by a user was adjusted, the glossiness adjustment was achieved by exchanging a plurality of toners having different glass transition points. Thus, the user was required to select an appropriate toner when the glossiness in the area designated by the user was adjusted. Further, the user took some time or effort to set the selected toner every glossiness adjustment. In the present invention, how to adjust the glossiness in the area designated by the user is obtained as mode information and on the basis of the obtained mode, control is effected so that a transparent image is selectively formed in the area designated by the user or an image formable area except for the area designated by the user.

Abstract: An image forming apparatus includes control device for selectively executing a first mode in which the non-transparent toner image is formed, then the transparent toner image is formed on the sheet not yet heated, then the sheet is subjected to the heating or a second mode in which the non-transparent toner image is formed, then the transparent toner image is formed on the sheet subjected to the heating, then the sheet is subjected to the heating; and storing device for storing selection information compared with information of amount of the non-transparent toner image, wherein the selection information indicates which mode provides larger difference in glossiness of the image fixed by the fixing device between when the transparent toner image of a predetermined amount is overlaid on the non-transparent toner image of a amount to be formed on the sheet and when the transparent toner image is not overlaid.

Abstract: A fixing device includes a belt heating a toner image on recording material, a member slidable on the belt inner surface, a pressor pressing the belt against the member to form a recording material nip, and a projection and recess provided on a nip forming surface of the member. When pressure applied when a toner temperature of the toner image reaches a softening temperature T1 (° C.) is P1 (kgf/cm2), pressure applied when the toner temperature reaches an incipient fluidization temperature T2 (° C.) is P2 (kgf/cm2), the toner temperature when P(t)/?(t) wherein ?(t) is a toner melt viscosity (Pa·s) and P(t) is a pressure (kgf/cm2) applied with the toner melt viscosity ?(t) is maximum is T3 (° C.), and pressure applied when the toner temperature reaches T3 (° C.) is P3 (kgf/cm2), the following relationships are satisfied: 0.3<P1/(P1+P2+P3),??1) 0.3<P2/(P1+P2+P3), and??2) 0.2<P3/(P1?P2+P3)<0.3.

Abstract: An image forming apparatus includes a color toner image forming portion, a transparent toner image forming portion, a heating portion, an obtaining portion that obtains information on an area where a gloss level should partly be increased and an area where the gloss level should partly be decreased in an image, and a controller controls the color toner image forming portion and the transparent toner image forming portion to form the color toner images and a first partial transparent toner image on a recording material, controls the heating portion to heat the color toner images and the first partial transparent toner image on the recording material, controls the transparent toner image forming portion to form a second partial transparent toner image on the recording material, and controls the heating portion to heat the second partial transparent toner image on the recording material based on information obtained by the obtaining portion.

Abstract: An image forming apparatus includes a color toner image forming portion for forming a toner image with a color toner on a recording material; a clear toner image forming portion for forming a toner image with a clear toner on the recording material, wherein the clear toner has a melt viscosity, at a fixing temperature, higher than that of the color toner; a fixing device for fixing the toner image formed on the recording material; an obtaining portion for obtaining information on an area in which designated glossiness is partly increased, partly decreased, or partly increased and decreased; and a control device for determining the order of formation of the toner image with the color toner and the toner image with the clear toner on the recording material depending on the information obtained by the obtaining portion.

Abstract: When glossiness in an area designated by a user was adjusted, the glossiness adjustment was achieved by exchanging a plurality of toners having different glass transition points. Thus, the user was required to select an appropriate toner when the glossiness in the area designated by the user was adjusted. Further, the user took some time or effort to set the selected toner every glossiness adjustment. In the present invention, how to adjust the glossiness in the area designated by the user is obtained as mode information and on the basis of the obtained mode, control is effected so that a transparent image is selectively formed in the area designated by the user or an image formable area except for the area designated by the user.

Abstract: In an image heating apparatus, the following expressions are satisfied: ?2<?1 0.2<?1<0.5 0.005<?2<0.3 0.9<V2/V1<1.0 where ?1 is a friction coefficient between a fusing roller (heating rotary member) and a pressing belt (endless belt), ?2 is a friction coefficient between the pressing belt and a driving roller, V1 is a peripheral speed of the fusing roller, and V2 is a peripheral speed of the driving roller.

Abstract: A belt nip type fixing apparatus, which prevents a formation of an icicle-like uneven glossiness occurring on a surface of a fixed image due to pressure release in a fixing nip. In addition, an image forming apparatus provided with the fixing apparatus for preventing an occurrence of image failure even in a case where a coated paper sheet, which is most likely to cause the image failure, is used as a recording material and for enlarging a scope of application of the recording material while maintaining a productivity, to thereby attain an improved merchantability. The apparatus is configured such that a wedge-shaped space, which is formed between a belt, a separation roller, and a pressure pad, is adequately filled by a sliding sheet, thereby preventing a pressure in the fixing nip from being decreased.