Abstract: The purpose of the present invention is to provide an LED lighting circuit, which can normally light an LED even if an alternating current power supply is an electronic transformer, an LED illuminating device, and a socket for an LED illuminating unit. Disclosed is an LED lighting circuit includes a rectifier circuit for rectifying an AC output from an AC power supply, an LED drive unit, which drives the LED by having rectifying output inputted thereto from the rectifying circuit, a reverse current preventing unit, which is provided between the rectifying circuit and the LED drive unit, and a terminal voltage control unit, which reduces the output terminal voltage of the rectifying circuit in the case where the alternating current output from the alternating current power supply is unstable or stopped. Also provided are an LED illuminating device, and a socket for an LED illuminating unit.

Abstract: An object of the invention is to provide an LED drive circuit that can suppress the generation of harmonic noise. The LED drive circuit includes a rectifying circuit an LED array, and a current supply circuit which includes a capacitor and a time constant adjusting element, wherein the discharge time constant of the current supply circuit is set longer than the charge time constant of the current supply circuit, and wherein during a period of time when the magnitude of AC commercial power supply voltage is larger than the light emission threshold of the LED array, current to the light-emitting circuit is supplied mostly from the rectifying circuit, and during a period of time when the magnitude of AC commercial power supply voltage is not larger than the light emission threshold of the LED array, current to the light-emitting circuit is supplied from the current supply circuit.

Abstract: The purpose of the present invention is to provide an LED lighting circuit, which can normally light an LED even if an alternating current power supply is an electronic transformer, an LED illuminating device, and a socket for an LED illuminating unit. Disclosed is an LED lighting circuit includes a rectifier circuit for rectifying an AC output from an AC power supply, an LED drive unit, which drives the LED by having rectifying output inputted thereto from the rectifying circuit, a reverse current preventing unit, which is provided between the rectifying circuit and the LED drive unit, and a terminal voltage control unit, which reduces the output terminal voltage of the rectifying circuit in the case where the alternating current output from the alternating current power supply is unstable or stopped. Also provided are an LED illuminating device, and a socket for an LED illuminating unit.

Abstract: An image forming apparatus includes an image holding member, a visible image detecting unit, a shielding part, a conveying passage, and a medium contact part. The visible image detecting unit includes a detecting part and detects a visible image, and the detecting part is disposed to face the image holding member. The shielding part is supported to be movable between a shielding position where the detecting part is shielded, and a detection permitting position where the detecting part is exposed. The medium contact part is supported to be movable between an entry position where the medium contact part enters a conveying passage, and a medium contact position where the medium contact part comes into contact with a medium and recedes from the entry position. The image forming apparatus moves the shielding part while interlocking with the movement of the medium contact part.

Abstract: A conveyance member includes: a rotating shaft; a plurality of support members that extend from the rotating shaft in a direction crossing an axial direction of the rotating shaft; and a plurality of arcuate members each having one end supported respectively by one of the support members, and having another end extending in a direction other than the axial direction so as to form an arc, wherein: when viewed in a direction perpendicular to the axial direction, there are a plurality of overlapping areas in which adjacent arcuate members overlap in the axial direction; and a length of at least one of the plurality of overlapping areas close to one end of the rotating shaft is greater than a length of each of the overlapping areas in the axial direction toward another end of the rotating shaft.

Abstract: An object of the invention is to provide an LED drive circuit that can suppress the generation of harmonic noise. The LED drive circuit includes a rectifying circuit an LED array, and a current supply circuit which includes a capacitor and a time constant adjusting element, wherein the discharge time constant of the current supply circuit is set longer than the charge time constant of the current supply circuit, and wherein during a period of time when the magnitude of AC commercial power supply voltage is larger than the light emission threshold of the LED array, current to the light-emitting circuit is supplied mostly from the rectifying circuit, and during a period of time when the magnitude of AC commercial power supply voltage is not larger than the light emission threshold of the LED array, current to the light-emitting circuit is supplied from the current supply circuit.

Abstract: A conveyance member includes: a rotating shaft; a plurality of support members that extend from the rotating shaft in a direction crossing an axial direction of the rotating shaft; and a plurality of arcuate members each having one end supported respectively by one of the support members, and having another end extending in a direction other than the axial direction so as to form an arc, wherein: when viewed in a direction perpendicular to the axial direction, there are a plurality of overlapping areas in which adjacent arcuate members overlap in the axial direction; and a length of at least one of the plurality of overlapping areas close to one end of the rotating shaft is greater than a length of each of the overlapping areas in the axial direction toward another end of the rotating shaft.

Abstract: An image forming apparatus includes an image holding member, a visible image detecting unit, a shielding part, a conveying passage, and a medium contact part. The visible image detecting unit includes a detecting part and detects a visible image, and the detecting part is disposed to face the image holding member. The shielding part is supported to be movable between a shielding position where the detecting part is shielded, and a detection permitting position where the detecting part is exposed. The medium contact part is supported to be movable between an entry position where the medium contact part enters a conveying passage, and a medium contact position where the medium contact part comes into contact with a medium and recedes from the entry position. The image forming apparatus moves the shielding part while interlocking with the movement of the medium contact part.

Abstract: An image forming apparatus including: an outputted image density control portion that forms a patch image and determines an outputted image density control condition based on a comparison result of the density of the patch image with a preliminarily set target value; a pixel count portion capable of counting the amount of image pixel at the time of image formation; a pixel count value accumulating memory portion that accumulates and stores the pixel count value; a toner supply portion; a toner supply amount measuring portion capable of measuring the amount of toner supplied to the developing device; a toner supply amount accumulating memory portion that accumulates and stores the toner supply amount; and a target value correcting portion that corrects the target value of the density of the patch image from the relation between a pixel count accumulating value and a toner supply amount accumulation value, is provided.

Abstract: An image forming apparatus including: an outputted image density control portion that forms a patch image and determines an outputted image density control condition based on a comparison result of the density of the patch image with a preliminarily set target value; a pixel count portion capable of counting the amount of image pixel at the time of image formation; a pixel count value accumulating memory portion that accumulates and stores the pixel count value; a toner supply portion; a toner supply amount measuring portion capable of measuring the amount of toner supplied to the developing device; a toner supply amount accumulating memory portion that accumulates and stores the toner supply amount; and a target value correcting portion that corrects the target value of the density of the patch image from the relation between a pixel count accumulating value and a toner supply amount accumulation value, is provided.

Abstract: An electrophotographic printing device using a light source for emitting predetermined light and a photosensitive material on which an electrostatic latent image is formed by the light from the light source. The electrophotographic printing device has a memory for storing density control information on light intensity of the light source and density of an image formed on a printing medium, and a light intensity controller for controlling the light intensity of the light source based on the information in the memory. The density control information stored in the memory is determined from a relationship between the density of the image to be formed and potential of the electrostatic latent image, and a relationship between the potential of the electrostatic latent image and the light source.

Abstract: In a control method for a transfer roller, after detecting an interval between a first recording medium and a second recording medium following the first recording medium, one of a first control mode and a second control mode is selected. If the first control mode is selected, and if the interval is not longer than a time period corresponding to one turn of the transfer roller, the transfer roller is kept at a first voltage until a second transfer to the second recording medium is completed. If the second control mode is selected, and if the interval is longer than the time period corresponding to one turn, the transfer roller changes between the first voltage and a second voltage which are opposite in polarity, before the second transfer to the second recording medium.

Abstract: When a resolution R (dpi) and a process speed (mm/sec) are determined, a voltage generating circuit 100 applies to a charging member a voltage consisting of an AC component having a frequency f which lies in a range having a maximum value and a minimum value determined by RS/25.4.+-.120 (Hz), and a DC component superimposed on the AC component. The DC voltage should only be 0.5 kV to 1.2 kV while the peak-to-peak voltage of the AC component is selected to be slightly higher than the DC voltage. The peak-to-peak voltage should be higher than a discharge start voltage; a sufficient discharge occurs when it ranges from 0.9 kV to 1.3 kV. In this configuration, not only clear-cut character images are printed without regard to changes in environment, but also mesh images are free from moire and vertical stripes.

Abstract: A developing device for an electrophotographic image forming apparatus has a toner layer regulating member which presses a toner carrier with a bent portion thereof and extends in a direction generally opposite to an intended direction of rotation of the toner carrier. The toner carrier is made of silicone rubber, urethane rubber or similar elastic material while the toner layer regulating member is implemented as a spring member made of metal.