摘要:
An image forming apparatus including a developing unit for stocking a developing agent containing toner and forming a toner image on a photosensitive medium with the developing agent, a toner supply unit for supplying the toner to the developing unit, a toner specific concentration detecting unit for detecting the toner specific concentration of the developing agent stocked in the developing unit, a humidity detecting unit for detecting humidity in the neighborhood of the developing unit, a storage unit for storing the humidity information detected by the humidity detecting unit, and a toner specific concentration correcting unit for controlling the toner supply amount of the toner supply unit on the basis of the humidity information stored to correct the toner specific concentration, wherein the toner specific concentration correcting unit compares newly-detected humidity with reference humidity corresponding to the humidity which is detected at the time when the developing agent is stocked into the developing unit or exchanged by new developing agent and which is stored in the storage unit, and corrects the toner specific concentration in accordance with the comparison result.
摘要:
In case of a developing density correction based on a test image (patch image) density, normally, the developing density is carried out in a short period of time by correction (γ correction) of a developing bias and a grid voltage (S11). When a correction amount of the γ correction exceeds an ordinary range, the γ correction (S11) and adjustment of toner concentration (magnetic permeability reference value) (S5) are carried out in combination. Furthermore, when the toner concentration is changed, the setting of a correction reference of the γ correction (γ correction TBL) and correction timing of the γ correction are accordingly changed (S6, S7). Therefore, in the developing density correction based on the test image density in the developing device using binary developer, it is possible to carry out the developing density correction, which is carried out in a short time, and whose correction width is wide, while maintaining the accuracy of a developing density adjustment.
摘要:
In case of a developing density correction based on a test image (patch image) density, normally, the developing density is carried out in a short period of time by correction (γ correction) of a developing bias and a grid voltage (S11). When a correction amount of the γ correction exceeds an ordinary range, the γ correction (S11) and adjustment of toner concentration (magnetic permeability reference value) (S5) are carried out in combination. Furthermore, when the toner concentration is changed, the setting of a correction reference of the γ correction (γ correction TBL) and correction timing of the γ correction are accordingly changed (S6, S7). Therefore, in the developing density correction based on the test image density in the developing device using binary developer, it is possible to carry out the developing density correction, which is carried out in a short time, and whose correction width is wide, while maintaining the accuracy of a developing density adjustment.
摘要:
A developing device having a reduced size in the horizontal direction and in which a developing agent is transported with stirring along a circulating route inside a developing tank to effectively mix newly added toner therewith and stir the mixture. A developing tank for storing developing agent therein is horizontally divided with a partition member thereby providing an upper chamber and a lower chamber. A developer roller and a stirring roller are disposed in the lower chamber. Two screw rollers are disposed in the upper chamber. An inlet opening is formed between an end of the partition member and a regulating member for restricting a layer if the developing agent adsorbed to the developing roller. A developing agent removed by the restricting member is fed through an inlet opening to the screw rollers in the upper chamber. The developing agent is mixed with fresh toner supplied through a supply inlet and transported with being stirred by the screw roller in its axial direction. Then, the developing agent is transferred to the screw roller disposed parallel to the screw roller and it is further transported and returned to the stirring roller in the lower chamber through a return port provided opposite to the screw roller. The compact construction of the developing device is realized by arranging screw rollers for stirring and transporting toner in the upper chamber.
摘要:
An object of the present invention is to obtain, in an accurate and stable manner, an image density at a tone rise point in a low-density region in order to form a stable image. At the time of execution of an image density correction in an image forming apparatus which employs an electrophotographic process, a toner pattern of a plurality of toner patches is formed on the basis of a reference density correction table which specifies an image density output value used for correction of an image density input value, the density of the toner patches is detected by a density detecting sensor, points corresponding to a plurality of image densities in a low-density region, detected above a predetermined level of sensitivity of the sensor, are plotted thereby to find a linear interpolation formula, an image density in the low-density region below the predetermined level of sensitivity of the density detecting sensor is interpolated with the linear interpolation formula, a comparison between the reference density correction table and a result of the interpolation is made so as to correct the image density output value, and a correction table as a post-modification correction table is prepared. An actual image is prepared using the correction table.
摘要:
A high density detecting toner pattern is formed on a photosensitive body and a high density correction is effected by comparing a value detected by a reflection sensor with a high density reference value so as to maintain an image density at a specific level. An image density correcting section adopts a result of the preceding high density correction as the high density reference value, and compares the same with a result of a current high density correction. The image density correcting section effects the half-tone density correction only when a difference reaches or exceeds a preset difference reference value by forming a half-tone density detecting toner pattern on the photosensitive body and comparing a value detected by the reflection sensor with a half-tone reference value. Consequently, it has become possible to provide an image forming apparatus which can maintain a density output of an entire image at a specific level for any kind of images including solid, line, and half-tone, etc. while shortening a time required for the density correction and reducing a quantity of toner consumed for the density correction.
摘要:
A projection exposure apparatus has a pattern lighting optical system including an exposure light source for lighting a pattern on a photomask, a projection optical system for forming an image of the pattern lighted by the exposure light source on the surface of a wafer, an alignment lighting optical system including an alignment light source for lighting alignment marks on the photomask and the wafer, and an alignment optical system for detecting relative positional relationship between the mask pattern and the wafer through the projection optical system, and further the projection optical system includes an image-forming system which exhibits two extremums of axial aberration as a function of wavelength.
摘要:
An optical apparatus comprising a laser light source, an optical system for focusing a beam of light from the laser light source onto an object surface through an objective lens and a spatial filter disposed at the entrance pupil of the objective lens or at a position conjugated with the entrance pupil, wherein the origin of the divergence of the laser beam having an angle of divergence emitted from the laser light source is projected on the entrance pupil of the objective lens by the optical system.
摘要:
An illumination optical system comprises a multi-beam generator which includes a plurality of each of two kinds of lens elements different in optical characteristics and which is interposed between a source for generating a collimated light beam and a light condenser. The multi-beam generator generates a large number of secondary light sources from the collimated light beam. The illumination optical system is capable of supplying illuminating light rays having an extremely uniform illumination distribution.
摘要:
A mirror converging-type illumination optical system for converging light rays from a light source into substantially parallel light rays using a concave reflecting mirror having a secondary curved surface comprises a conical refraction member having a convex conical refraction surface at an input or incident side thereof and another convex conical refraction surface at an output side thereof. The refraction member is arranged in a path of the parallel light rays with a vertex of the conical refraction member being substantially aligned with the optical axis of the illumination optical system. The refraction member inverts the inner and outer portions of the incident parallel light rays. The absence of incident parallel light around the optical axis thereof is corrected to achieve a uniform intensity of light rays.