Abstract: A control part provides a first region in which an image is formed on an image carrier using only a dark-color toner. The control part provides a second region, which is adjacent to the first region, in which an image is formed using a dark-color toner and a light-color toner. The control part provides a third region in which an image is formed using only a light-color toner at the boundary of the first and second regions. The control part controls a latent-image forming unit, a light-color developing unit and a dark-color developing unit so as to form an image in which these regions are provided. The control part may provide a third region in which neither a light-color toner nor a dark-color toner is used at the boundary of the first and second regions.

Abstract: An image forming apparatus capable of reliably positioning a process unit in a main image forming apparatus body, without impairing ease of mounting/dismounting of the process unit achieved by a simple structure. The image forming apparatus including a convex section, provided on the process unit, that projects towards the insertion side; an engagement section, provided on the main apparatus body, that positions the process unit in a width direction by engaging with the convex section; and a guidance section, provided on at least one of a tip end of the convex section and the main apparatus body, that guides the convex section towards the guidance section when mounting the process unit.

Abstract: An image forming apparatus forms an excellent-quality image by using a recycle developer obtained by recovering a developer remaining on an image carrier.

Abstract: An image forming apparatus includes: photosensitive members; an endless belt facing the photosensitive members; developing rollers respectively supplying, to the photosensitive members, developer of different colors which is charged to a first polarity; cleaning rollers adjacent to the photosensitive members; a separating mechanism separating the developing roller from the photosensitive member in a single color printing. If in a multi color printing, a control unit applies a cleaning bias whose polarity is a second polarity opposite to the first polarity and which holds a first electric potential to each cleaning roller. If in the single color printing, the control unit executes a bias reduction control in which a cleaning bias applied to the cleaning roller not used in the single color printing is given the second polarity and is made to hold a second electric potential whose absolute value is smaller than that of the first electric potential.

Abstract: Electrographic printing of one or more multi-channeled layers having a particular pattern by electrographic techniques. Such electrographic printing includes the steps of forming a desired print image, electrographically, on a receiver member utilizing predetermined sized marking particles; and, where desired, forming one or more final multi-channeled layers utilizing marking particles of a predetermined size or size distribution.

Abstract: A color electrophotographic image forming apparatus including: an opening in a main body; a door opening and closing the opening; a first tray movable between an inside position and an outside position through the opening while removably supporting drum cartridges having photosensitive drums; a second tray movable between the inside position and the outside position through the opening while removably supporting developing cartridges having developing rollers; a transfer member to which toner images are transferred from the photosensitive drums; and a positioning member, which releases, when the door is opened, an engagement between engaging portions of the developing cartridges and engaged portions of the drum cartridges to hold the developing cartridges so that the second tray can be pulled out, and which engages, when the door is closed, the engaging portion with the engaged portion to position the developing cartridges for image formation.

Abstract: Provided is an image forming apparatus in which one of developing units that respectively contain visible toners of black, yellow, magenta, and cyan other than the developing unit that contains the visible toner of black is replaced by a developing unit that contains a transparent fluorescent toner. Consequently, a document image can be expressed by the visible toner of black and a designated color which falls within a color reproduction range determined by two of the visible toners of yellow, magenta, and cyan, and an additional pattern which is an additional information image for preventing falsification and forgery can be printed on the document image with the use of the transparent fluorescent toner.

Abstract: The carrier is used for a two-component developer for developing an electrostatic latent image, and includes a particulate magnetic core material; and a cover layer located on a surface of the particulate magnetic core material and including a crosslinked material. The crosslinked material is formed by hydrolyzing a copolymer including at least a unit (A) having a specific acrylic siloxane structure including a tris(trialkylsiloxy)silanyl group and a unit (B) having a specific acrylic silicone structure to form a material having a silanol group, and subjecting the material having a silanol group to a condensation reaction using an organic zirconium-containing catalyst.

Abstract: A plurality of photosensitive drums is positioned between a first side plate and a second side plate of a holder unit. The first side plate is formed with a plurality of openings. Each of a plurality of toner cases supports each developing roller and is positioned between the first side plate and the second side plate. Each toner case has a confronting surface confronting the first side plate. Each of a plurality of developer couplings is provided at the confronting surface at a position in alignment with each opening and receives an input force to rotate each developing roller. A fixing member has a plurality of intervenient portions and a connecting portion integrally linking neighboring intervenient portion together. Each intervenient portion is interposed between each opening and each developer coupling to fix a position of each toner case relative to the holder unit.

Abstract: A multi-mode, long life monochrome printing system that includes (a) a media supply assembly having a media path (b) a moveable intermediate transfer member for receiving images from image output terminal assemblies and for transferring the images to media on the media path; and (c) a plural number of monochrome image output terminal (IOT) assemblies adjacent the moveable intermediate transfer member, each monochrome image output terminal (IOT) assembly being selectably moveable into and out of image transfer relationship with the moveable intermediate transfer member, and each monochrome image output terminal (IOT) assembly having a development unit including developer material having essentially a same color.

Abstract: An image forming apparatus includes process units arranged in a predetermined direction to form a process-unit row, each having a photosensitive body and a developer container; a casing accommodating the process units and having a cover opening and closing an opening formed at one side in the predetermined direction, and an exposure member exposing the photosensitive body, and having a laser source, a deflector, and an optical element, and the exposure member is arranged facing the developer container of each process unit in a direction orthogonal to the predetermined direction. The process units are detachable from the casing, through the opening of the casing, and the developer container of one process unit arranged at one end of the process-unit row has a protruding portion protruding toward the exposure member to overlap with the exposure member in the orthogonal direction.

Abstract: An image forming apparatus includes: a plurality of image forming units each with an image carrier on which an electrostatic latent image is formed, and each with a developing member for developing process on the electrostatic latent image, wherein the image forming apparatus superimposes toner images of the respective colors to form a composite color image; when images on a plurality of pages are formed, the developing members of the respective colors are started or stopped in response to presence or absence of latent images of the respective colors on a page that is targeted for image formation; and when the image forming unit starts to be driven, a developing member, corresponding to a color whose latent image is not to be formed on a first page of the plurality of pages, is not started.

Abstract: A xerogrpahic system and method use a tri-level development process in which at least one xerographic imaging unit includes a photoreceptor and a pair of developer units. A first developer unit includes a conventional first toner of a given color (CYMK) and a second developer unit includes a hypochromatic light form of the first toner. By use of a specific tri-level process, excellent color-to-color registration can be achieved for each processed color separation because overlap between colorants can be prevented. Moreover, by use of two forms of the same colorant, a smoother tone reproduction curve can be achieved when an aggressive blending strategy is used. Gamut loss and ink limit violation can be avoided by adjusting the blending curve in certain situations.

Abstract: Disclosed is a manufacturing method for forming a full color image and an apparatus for forming a full color image exhibiting excellent color chroma for a secondary color and extension of a color reproduction area in a range of red to orange color. A method for forming a full color image using at least six colors of an electrostatic image developing toner each comprising a resin and a colorant, wherein six colors of an electrostatic image developing toner are a yellow toner, a magenta toner, a cyan toner, an orange toner, a green toner and a black toner, and the colorant containing in the orange toner is a pyrazolone pigment.

Abstract: This invention provides an image forming apparatus, which attains a uniform gloss level of an overall image by preventing regions having different gloss levels from being generated on the image to be formed upon execution of image formation using a transparent toner, and a control method thereof. To accomplish this, an image forming apparatus of this invention identifies pixels to be developed using only a black toner of colored toners from an image signal of an image to be formed on a printing material upon execution of image formation using the transparent toner. Furthermore, the image forming apparatus executes exposure control so as to perform development using the transparent toner in an amount required to reduce a gloss level difference between the pixels to be developed using only the black toner and those to be developed using the colored toners other than the black toner.

Abstract: The present application is directed to methods for determining when to transition between printing color images and printing black-only images in an image forming device. A variety of factors may be evaluated in order to select a trigger value. An examined portion of a print history and an examined portion of a print queue may be evaluated to determine one or more test values. Based on a comparison of the one or more test values with the trigger value, a determination may be made whether to transition between color printing and black-only printing.

Abstract: An image forming apparatus including cyan (C), magenta (M), yellow (Y), and black (K) developing units using a C developer, a M developer, a Y developer, and a K developer, respectively; at least one auxiliary developing unit using a developer other than the C, M, Y, and K developers; a plurality of photosensitive media formed in the C, M, Y, and K developing units and the auxiliary developing unit, respectively; a plurality of cleaning members formed in the C, M, Y, and K developing units and the auxiliary developing unit, respectively, so as to clean surfaces of the plurality of photosensitive media; and waste developer storage units formed in the C, M, Y, and K developing units and the auxiliary developing unit, respectively, so as to collect waste developer cleaned by the plurality of cleaning members.

Abstract: An image forming apparatus includes a plurality of image forming units for forming a developer image on an image supporting member; a transfer unit for transferring and overlapping the developer image on a medium to form a developer laminated portion; and a fixing unit for fixing the developer laminated portion. One of the image forming units uses transparent developer having a softening point higher than that of color developer used in the other of the image forming units, and having an average particle size larger than that of the color developer.

Abstract: A white toner for electrostatic charge image development is disclosed. The white toner for electrostatic charge image development includes a binder resin, a first white pigment, a second white pigment, and a release agent, a specific gravity D1 of the first white pigment satisfying a condition of 3.5<D1<6.0, a specific gravity D2 of the second white pigment satisfying a condition of 0.3<D2<1.2, a total content of the first white pigment and the second white pigment being in the range of from about 20% by weight to about 50% by weight with respect to a total weight of the white toner for electrostatic charge image development, and the release agent including a metal salt.

Abstract: An image forming apparatus includes a first image forming portion for forming a developer image, said first image forming portion including a first image supporting member for forming a static latent image and a first developing member for attaching developer to the static latent image; a second image forming portion for forming a developer image, said second image forming portion including a second image supporting member for forming a static latent image and a second developing member for attaching developer to the static latent image; a transfer portion for transferring the developer image to a printing medium; and a fixing unit for fixing the developer image to the printing medium. The second developing member has a surface roughness greater than that of the first developing member. The fixing unit is disposed at a position closer to the first image forming portion relative to the second image forming portion.

Abstract: Clutch mechanism includes support plate, input element to which driving force is input, output element configured to rotate upon receiving driving force, first elastic member configured to bias output element toward support plate, first member including sliding arm inserted through through-hole of support plate and first slide surface, and second member configured to accommodate first member and including second slide surface. Insertion of the sliding arm into through-hole prevents rotation of first member with respect to support plate but allows first member to approach and move away from support plate. Output element moves apart from input element to cut off driving force when second member is in first rotational position. When second member rotates to second rotational position, output element outputs driving force transmitted from input element.

Abstract: An image forming apparatus includes a detaching and pressing mechanism for releasing developing rollers of developer cartridges mounted in a drum unit from photosensitive drums and pressing the developing rollers on the photosensitive drums. The detaching and pressing mechanism includes a pair of translation members, intermediate members provided on the translation members, cam holders for holding the translation members in such a manner as to be linearly movable in an anteroposterior direction, and a synchronous movement mechanism for allowing the pair of translation members to linearly move in synchronization.

Abstract: An image forming apparatus, comprises an image forming section, a transfer section to transfer the toner image onto a recording material; and a fixing device to fix the toner image onto the recording material; wherein the image forming section includes a plurality of color image forming sections and a transparent image forming section, and the plurality of color image forming sections and the transparent image forming section are arranged such that the transparent image is transferred so as to form a transparent image layer on an outer surface of the color image on the recording material at a fixing time by the fixing device, and wherein an amount of wax contained in the transparent toner is larger than an amount of wax contained in each color toner of the plurality of color toners and smaller than an amount of base resin contained in the transparent toner.

Abstract: An image forming apparatus and a power transmission device capable of intermittently transmitting power reliably to a plurality of driven bodies from a driving source with a small number of clutches. The power transmission device includes a cam part which rotates by receiving power of the driving source, a clutch device which intermittently transmits the power to the cam part to determine a stop position of the cam part, a first power transmission unit which transmits the power to any one of the plurality of driven bodies according to the stop position of the cam part, and a second power transmission unit which transmits the power to the other driven bodies of the plurality of driven bodies according to the stop position of the cam part. The cam part includes a rotating disc and a plurality of press members which are provided on one surface of the rotating disc to press the first power transmission unit and the second power transmission unit according to the stop position of the rotating disc.

Abstract: The developing agent is selected to have a distribution of adhesive force to the surface of an image carrier, which is configured such that the ratio of the developing agent having an adhesive force which is not less than 2.5 times as high as an average value of a distribution of adhesive force is 3% by weight or less based on an entire weight of the developing agent.

Abstract: A method and system for printing image documents using a variety of toners where some toners using a multi-development station having two or more development stations. These toners are co-printed prior to fixing, on the receiver by the multi-development station.

Abstract: A toner set is composed of toners of a plurality of colors that are used in a tandem-type color image forming apparatus. Each of the toners of a plurality of colors includes toner base particles and an external additive. The external additive includes small-diameter silica particles and large-diameter silica particles larger than the small-diameter silica particles. When, of the toners of a plurality of colors, three color toners to be used consecutively for forming the toner image are defined as a first toner, second toner and third toner respectively in order of usage thereof, the average particle diameter of the large-diameter silica particles contained in the second toner is smaller than the average particle diameter of the large-diameter silica particles contained in the first toner and is larger than the average particle diameter of the large-diameter silica particles contained in the third toner.

Abstract: An image forming apparatus is provided. The image forming apparatus includes electrostatic latent image carriers, developer devices, an endless belt, a cleaning roller, a first motor, a first gear train, being coupled to the cleaning roller to rotate in a predetermined direction when the first motor rotates in a first direction and decoupled from the cleaning roller when the first motor rotates in a second direction, a second gear train, being coupled to the cleaning roller to rotate in the predetermined direction when the first motor rotates in the second direction and decoupled from the cleaning roller when the first motor rotates in the first direction, and a third gear train, being coupled to at least one of the developer devices when the first motor rotates in the first direction and decoupled from the at least one of the developer devices when the first motor rotates in the second direction.

Abstract: A transparent toner for electrophotographic image forming method forming an image on a recording medium with one or more chromatic toner and a transparent toner, including a thermoplastic resin; and a lubricant, wherein the transparent toner has a tangent loss (tan ?) determined by the following formula has a maximum peak value not less than 3 in a range of from 80 to 160° C.: tangent loss (tan ?)=loss elastic modulus (G?) of the transparent toner/storage modulus (G?) thereof.

Abstract: A toner set has toners used in an image forming method by forming a toner image with toners of several colors and fixing the toner image onto a recording medium. The toners include first and second toners of different colors. The first and second toners contain toner base particles including a binding resin, a colorant and a wax. The colorant of the first toner contains a quinacridone pigment. The wax includes a carnauba wax and a wax other than the carnauba wax. The base particles of the first toner have a mass % Wq1 of carnauba wax and Wo1 of the other wax and the base particles of the second toner have a mass % Wq2 of carnauba wax and Wo2 of the other wax. These mass % values are selected to satisfy the following: Wq1/(Wq1+Wq2)<Wo1/(Wo1+Wo2) 3?Wo1+Wo2<Wq1+Wq2?10.

Abstract: An image forming apparatus includes developing units designed to have an appropriate developer storage capacity in consideration of developer consumption, and improved convenience of use. The image forming apparatus also includes an image carrier, and plural developing units arranged along a rotating direction of the image carrier to supply developers to the image carrier. The plural developing units include a first developing unit having the largest developer storage capacity and a second developing unit having the second largest developer storage capacity after the first developing unit.

Abstract: An image forming apparatus forming a color image on a recording material mounts black and non-black process cartridges including a photosensitive drum and a developing roller and includes a driving source; first and second clutches connecting and disconnecting the driving source and the developing roller of the black and non-black cartridges, respectively; first and second members actable on the first and second clutches, respectively, each for switching between operation and non-operation states for respectively transmitting and not transmitting a driving force to the developing rollers; and a switching member, movable by the driving force of the driving source and actable on the first and second members for switching among first, second, and third modes, for respectively transmitting the driving force to the developing rollers of all of the process cartridges, to any one of the developing rollers, and only to the developing roller of the black process cartridge.

Abstract: Provided is a full color image forming method wherein high color reproducibility especially on a blue system and a green system can be obtained and an excellent gradation property can be obtained in a full color image to be obtained. The full color image forming method for forming a full color image by using at least yellow toner, magenta toner, and two kinds of cyan toners (1, 2) is characterized in that a toner image formed by the cyan toner (1) alone has the value of the maximum color saturation (C*) of not less than 50 and the value of lightness (L*) in a color space represented by an L*a*b* colorimetric system of not less than 30 and not more than 52, and that a toner image formed by the cyan toner (2) alone has the value of the maximum color saturation (C*) of not less than 50 and the value of the lightness (L*) in the color space represented by the L*a*b* calorimetric system of not less than 58 and not more than 75.

Abstract: A developing method in an image-forming device is provided. The developing method includes the steps of charging a photoreceptor; exposing the photoreceptor to form a first latent image on the photoreceptor; developing the first latent image by a first developing unit having a first potential to form a first toner image; and discharging the photoreceptor having the first toner image, such that when the photoreceptor is charged again, the first toner image on the photoreceptor has a second potential, and the second potential is approximately the same as the first potential of the first developing unit.

Abstract: A method and device for controlling toner transfer during the formation of a toner image within an image forming device is described herein. One exemplary image forming device includes a toner reservoir that stores toner of a first color, a developer member that receives toner from the toner reservoir, a photoconductive member proximate the developer member that receives toner from the developer member, and a driver. While rotating the photoconductive member, the driver selectively rotates the developer member based on a color content of the image. For example, the driver does not rotate the developer member while rotating the photoconductive member when the toner image being formed lacks the first color. Alternatively, the driver lows the rotational speed of the developer member while rotating the photoconductive member when the toner image being formed lacks the first color.

Abstract: An image forming apparatus forms a stamp image with a stamp image developer having a color developing temperature at a color erasing temperature of an image forming developer, and forms a mask image with a mask image developer having a color re-developing temperature at a temperature not lower than a color re-developing temperature of the image forming developer. Accordingly, when a confidential document is color-erased, the stamp image develops color, and when the color-erased confidential document again develops color, it can not be read.

Abstract: An image forming device includes a plurality of image forming units provided in parallel comprising a black image forming unit to form a black toner image and a plurality of color image forming units to form color toner images, an intermediate transfer device to primarily transfer color toner images formed by superimposing the toner images formed at each image forming unit, and a secondary transfer unit to transfer the color toner image to a transfer paper. The color image forming unit employs a non-magnetic-contact-type single-component development device to develop each color toner image with a single-component developer, and the black image forming unit is provided closest to the secondary transfer unit and employs a contact-type two-component development device to develop a black toner image with a two-component developer.

Abstract: An image forming apparatus includes a developing apparatus for developing an electrostatic image with a developer comprising at least a toner and a first external additive, the developing apparatus including a plurality of developing devices, containing toners different in color or lightness from each other, in which at least two developing devices contain a dark color toner and a light color toner which have an identical hue and different lightnesses and the developing device containing the light color toner is subjected to a developing operation prior to another developing device; a first transfer apparatus for sequentially transferring toner images, which have been developed by the plurality of developing devices, onto an intermediary transfer member; and a second transfer apparatus for transferring the toner images from the intermediary transfer member all together onto a transfer medium The first external additive includes particles having an aspect ratio of not less than 1.0 and not more than 1.

Abstract: An image forming apparatus capable of performing monochrome printing and color printing in which all the developing units share a single development transformer is constructed such that at the time of monochrome printing the photoreceptor drums for colors are stopped rotating while all the developing units are constantly applied with a high voltage. Further, the cumulative operation time in which the black photoreceptor drum has been operated for monochrome printing is calculated so that the color-printing photoreceptor drums which are stopped during monochrome printing are rotationally driven by a predetermined angle when the cumulative operation time exceeds predetermined fixed time. Thus, the surface of each color-printing photoreceptor drum that is being worn is restored by making the fresh surface of the drum oppose the associated color developing unit, whereby it is possible to prevent occurrence of defects on the surface of each photoreceptor drum.

Abstract: An image forming apparatus to enhance a user's convenience by adequately designing developer storage capacities of developing devices in consideration of an amount of consumed developer includes an image carrier, and plural developing devices arranged along a rotational direction of the image carrier to supply a developer to the image carrier. The plural developing devices include a first developing device having a largest developer storage capacity, and a second developing device disposed in a most downstream side with respect to the rotational direction of the image carrier. The second developing device has a second largest developer storage capacity.

Abstract: In a color image forming apparatus comprising a plurality of developing devices each provided with a developing roller structured with a developing sleeve and a fixed magnetic pole member, an agitating member, a recovering and feeding member, a regulating member and a developing device casing member, at least one of the plurality of developing devices has a different developer storing capacity and a different outer diameter of the recovering and feeding member for the other developing devices and has the same angle allocation values among the plurality of fixed magnetic poles in the fixed magnetic pole member.

Abstract: An image forming apparatus includes a first development unit, a second development unit, and a control unit. The first development unit forms a first developer image with a first developer absorbing a light having a prescribed wavelength. The second development unit forms a second developer image with a second developer permeating the light having prescribed wavelength therethrough. The control unit controls print of a background design image by the first development unit and print of a print image by the second development unit.

Abstract: Systems and methods of producing image products using printing are provided. The image products are produced by sequentially applying a base image, a first clear toner and a second clear toner. The first clear toner forms one or more lenses, and the first and second clear toners have different indexes of refraction. The image products produced by the systems and methods can be lenticular image products that display different images depending upon a viewing angle.

Abstract: Printing of information with a distinct tactile feel can be accomplished by electrographic techniques. Such electrographic printing includes the steps of forming a desired print image, electrographically, on a receiver member utilizing standard size marking particles; and in areas of the formed print image, forming raised information by printing at least a first raised image and a second raised image. The print and raised images are fixing on the receiver member. The raised images are applied using toner particles having diameters substantially larger than the diameters standard size toner particles used for applying the print image.

Abstract: A developing unit driving apparatus which drives a developing unit having a toner cartridge to accommodate a toner, a developing part disposed in the toner cartridge to develop the toner to a photosensitive body, and a toner supplying part provided in the toner cartridge to supply the toner to the developing part, the apparatus includes: a driving source; a first power transmitter which transmits power supplied from the driving source to the developing part; and a second power transmitter which transmits the power supplied from the driving source to the toner supplying part except when the developing part is driven.

Abstract: Provided are an image forming apparatus and a method for print control which can carry out printing using appropriate toners without selecting an apparatus to be used from apparatuses loaded with different toner groups depending on a print object. In an image forming apparatus provided with an image forming section including photoreceptor drums, writing units to form electrostatic latent images on the photoreceptor drums, and development devices to carry out development by feeding toners to the latent image, there are loaded, as the toners, a first toner group (for example, normal toners) containing three colors of CMY; a second toner group (for example, Vivid toners) containing three colors of CMY with a wider color reproduction area than the first toner group; and a K (black) toner.

Abstract: An image forming apparatus includes a detaching and pressing mechanism for releasing developing rollers of developer cartridges mounted in a drum unit from photosensitive drums and pressing the developing rollers on the photosensitive drums. The detaching and pressing mechanism includes a pair of translation cam members, intermediate members provided on the translation cam members, cam holders for holding the translation cam members in such a manner as to be linearly movable in an anteroposterior direction, and a synchronous movement mechanism for allowing the pair of translation cam members to linearly move in synchronization.

Abstract: An image forming apparatus includes a latent image bearing member and a developing portion having a plurality of developing devices provided facing the latent image bearing member, as well as an inputting portion for inputting an image signal, an auto-discriminating portion for automatically discriminating the kind of image input, and a control portion for changing between a first mode for executing monochrome image formation, a second mode for executing color image formation, and an auto-selecting mode for changing over between the first mode and the second-mode according to the discrimination of the auto-discriminating portion. In the auto-selecting mode, movement of a predetermined developing device to a predetermined position is started before the auto-discriminating portion makes the discrimination.

Abstract: An image forming apparatus having a plurality of image bearing members, a plurality of colored toner developing units, and a transparent toner developing unit. Each colored toner developing unit has a developer bearing member. The rotational direction of the developer bearing members of the colored toner developing units is opposite to the rotational direction of the corresponding image bearing member, and the rotational direction of the developer bearing member of the transparent toner developing unit is the same as the rotational direction of the corresponding image bearing member.

Abstract: A red toner for electrostatic image development, includes: a binder resin; a coloring agent; and a release agent, wherein the red toner for electrostatic image development satisfies the following formulae: 0.3<ID<1.2 5°<A<35° wherein ID represents an image density when a first image is formed on a recording material with a toner loaded amount of 4.0 g/m2 of the red toner; and A represents a hue angle of the first image expressed by an L*a*b* color coordinate space, provided that a hue angle of 0° is on the a*+ axis and a hue angle of 90° is on the b*+ axis.