Abstract: An apparatus includes an obtaining unit configured to obtain, using an optical coherence tomography, an analysis map for a disk and an analysis map for a macular area, which are analysis results of three-dimensional data obtained by capturing an image of a region of a fundus of a subject's eye that includes the disk and the macular area, and a control unit configured to cause a display unit to display side by side a two-dimensional image of the region including the disk and the macular area, the analysis map for the optic disk, and the analysis map for the macular area.

Abstract: An image forming apparatus includes a photosensitive member, a first developer carrying member for carrying a developer comprising toner and a carrier for developing an electrostatic image formed on the photosensitive member, and a second developer carrying member for carrying the developer received from the first developer carrying. The second developer carrying member is disposed downstream of the first developer carrying member with respect to a rotational direction of the photosensitive member. In addition, a voltage source applies a developing bias voltage to the first developer carrying member and second developer carrying member, and a driving device rotates the first developer carrying member at a peripheral speed higher than that of the photosensitive member and rotates the second developer carrying member at a peripheral speed which is higher than that of the photosensitive member and which is lower than that of the first developer carrying member.

Abstract: An image forming method using a two component developing system is provided in which a print speed is not less than 300 mm/s, a peak-to-peak voltage of an AC component in a developing bias is not more than 1.3 kV, a sufficient image density can be ensured, and a recorded image having a small amount of magnetic carrier remaining on the image and having high image quality can be obtained. A magnetic carrier that forms a two component developer contains a magnetic core and a resin. The magnetic core is a ferrite containing Sr and Ca inside thereof at the same time, having a small crystal grain diameter, a high density crystal-grain boundary structure, and an extremely large capacitance of the grain boundary. Use of the ferrite can provide the above method.

Abstract: An image forming method using a two component developing system is provided in which a print speed is not less than 300 mm/s, a peak-to-peak voltage of an AC component in a developing bias is not more than 1.3 kV, a sufficient image density can be ensured, and a recorded image having a small amount of magnetic carrier remains on the image and having high image quality can be obtained. A magnetic carrier that forms a two component developer contains a magnetic core and a resin. The magnetic core is a ferrite containing Sr and Ca inside thereof at the same time, having a small crystal grain diameter, a high density crystal-grain boundary structure, and an extremely large capacitance of the grain boundary. Use of the ferrite can provide the above method.

Abstract: A duty ratio Du (%), denoted by (T2/(T1+T2))×100, is in the range of 60?Du?80; a magnetic carrier has a resistivity ? which decreases in accordance with an increasing electric field strength, and a relative dielectric constant ? which increases in accordance with an increasing electric field strength; a product of a time constant ?0??(s) of electric charge decay in an electric field strength E2D decided by a second peak voltage V2 and a dark potential VD, and an electric field strength E2D satisfies a relation of 20??0?? E2D (s·V/cm); and a time constant ?0??(s) and a relative dielectric constant ? in an electric field strength E1L, which is decided by a first peak voltage V1 and a bright potential VL, satisfy the following relations: ?0??(s)?6.0×10?4, and 30??.

Abstract: In the formation of images by a two-component development system, provided is a magnetic carrier that can be used to output an image which has sufficient density, in which few white spots are present in a low-density portion located near the boundary between a high-density region and a low-density region, and in which the low-density portion has good graininess. The magnetic carrier contains magnetic carrier particles each of which has resin and a magnetic particle. The magnetic particle contains ferrite phases and phases comprising a perovskite-structured compound. The ferrite phases and phases comprising a perovskite-structured compound are combined.

Abstract: An image forming apparatus includes a developer carrying member to which a developing bias is applied. A frequency f of a developing bias waveform, a developing area S1 which is a time-integrated value of a difference between a voltage value of the developing bias and a solid electrostatic image potential VL in a developing period of the developing bias, a collecting area S2 which is a time-integrated value of a difference between the voltage value of the developing bias and VL in a collecting period of the developing bias, and a developing contrast value Vcon are used for defining a range of a value of the developing bias frequency f, a range of a value of a voltage change rate ? at VL during transition of the developing bias voltage value from a developing-side voltage to a collecting-side voltage, and a range of a value represented by the formula: {(S1?1.28×S2)×f/Vcon}×exp(?2.0×10?5×f/Hz).

Abstract: An image forming apparatus includes a photosensitive drum to which an electrostatic image is formed and a developing sleeve carrying a developer including toner carrier. An alternating voltage is applied to the sleeve to form an alternating electric field between the sleeve and the drum to develop the electrostatic image with the developer. A relation |K1|<|K2| is satisfied, where K1: a slope at an electric field intensity Ed=|(Vp2?VL)/D|, K2: a slope at an electric field intensity Eb=|(Vp1?VL)/D|, VL: a potential [V] of the electrostatic image at which a maximum density is obtained, Vp1: a peak potential [V] that provides a potential difference to move the toner toward the drum, Vp2: a peak potential [V] that provides a potential difference to move the toner toward the sleeve, and D: a closest distance [m] between the drum and the sleeve.

Abstract: A duty ratio Du (%), denoted by (T2/(T1+T2))×100, is in the range of 60?Du?80; a magnetic carrier has a resistivity ? which decreases in accordance with an increasing electric field strength, and a relative dielectric constant ? which increases in accordance with an increasing electric field strength; a product of a time constant ?0??(s) of electric charge decay in an electric field strength E2D decided by a second peak voltage V2 and a dark potential VD, and an electric field strength E2D satisfies a relation of 20??0?? E2D (s·V/cm); and a time constant ?0??(s) and a relative dielectric constant ? in an electric field strength E1L, which is decided by a first peak voltage V1 and a bright potential VL, satisfy the following relations: ?0??(s)?6.0×10?4, and 30??.

Abstract: An image forming apparatus includes a photosensitive drum to which an electrostatic image is formed and a developing sleeve carrying a developer including toner carrier. An alternating voltage is applied to the sleeve to form an alternating electric field between the sleeve and the drum to develop the electrostatic image with the developer. A relation |K1|<|K2| is satisfied, where K1: a slope at an electric field intensity Ed=|(Vp2?VL)/D|, K2: a slope at an electric field intensity Eb=|(Vp1?VL)/D|, VL: a potential [V] of the electrostatic image at which a maximum density is obtained, Vp1: a peak potential [V] that provides a potential difference to move the toner toward the drum, Vp2: a peak potential [V] that provides a potential difference to move the toner toward the sleeve, and D: a closest distance [m] between the drum and the sleeve.

Abstract: A carrier has an impedance Z having a frequency dependence, obtained by alternating current impedance measurement. When the frequency dependence is fitted by a fitting function, parameter ? lies in a range of 0.70 to 0.90 in an electric field of 103 V/cm.

Abstract: An image forming apparatus includes a photosensitive drum to which an electrostatic image is formed and a developing sleeve carrying a developer including toner carrier. An alternating voltage is applied to the sleeve to form an alternating electric field between the sleeve and the drum to develop the electrostatic image with the developer. A relation |K1|<|K2| is satisfied, where K1: a slope at an electric field intensity Ed=|(Vp2?VL)/D|, K2: a slope at an electric field intensity Eb=|(Vp1?VL)/D|, VL: a potential [V] of the electrostatic image at which a maximum density is obtained, Vp1: a peak potential [V] that provides a potential difference to move the toner toward the drum, Vp2: a peak potential [V] that provides a potential difference to move the toner toward the sleeve, and D: a closest distance [m] between the drum and the sleeve.

Abstract: An image forming apparatus includes a developer carrying member to which a developing bias is applied. A frequency f of a developing bias waveform, a developing area S1 which is a time-integrated value of a difference between a voltage value of the developing bias and a solid electrostatic image potential VL in a developing period of the developing bias, a collecting area S2 which is a time-integrated value of a difference between the voltage value of the developing bias and VL in a collecting period of the developing bias, and a developing contrast value Vcon are used for defining a range of a value of the developing bias frequency f, a range of a value of a voltage change rate ? at VL during transition of the developing bias voltage value from a developing-side voltage to a collecting-side voltage, and a range of a value represented by the formula: {(S1?1.28×S2)×f/Vcon}×exp(?2.0×10?5×f/Hz).

Abstract: An image forming apparatus includes a photosensitive drum to which an electrostatic image is formed and a developing sleeve carrying a developer including toner carrier. An alternating voltage is applied to the sleeve to form an alternating electric field between the sleeve and the drum to develop the electrostatic image with the developer. A relation |K1|<|K2| is satisfied, where K1: a slope at an electric field intensity Ed=|(Vp2?VL)/D|, K2: a slope at an electric field intensity Eb=|(Vp1?VL)/D|, VL: a potential [V] of the electrostatic image at which a maximum density is obtained, Vp1: a peak potential [V] that provides a potential difference to move the toner toward the drum, Vp2: a peak potential [V] that provides a potential difference to move the toner toward the sleeve, and D: a closest distance [m] between the drum and the sleeve.