Abstract: A developer bearing member includes a base body, a surface layer, and a plurality of concave portions provided on the surface layer, wherein a resistance value of the surface layer is 102 ?·cm to 108 ?·cm, the number of the concave portions per unit area is 2250/mm2 to 12254/mm2, a major diameter of an opening of the concave portion is 8 ?m to 20 ?m, a depth of the concave portion is 2 ?m to 5 ?m, a dimensional tolerance of the major diameter is 0.5 ?m or less, and a dimensional tolerance of the depth is 0.5 ?m or less.

Abstract: Energy consumption in a fixing process of an electrophotographic image-forming apparatus is reduced. An unfixed toner image T1 is fixed on a recording medium by applying a photopolymerizable composition D1 to the unfixed toner image T1 formed on the recording medium and then performing irradiation with light having a maximum emission wavelength in a wavelength range of from 420 to 470 nm using a light emitting diode or an organic EL device for curing the photopolymerizable composition D1 by photopolymerization.

Abstract: A toner image fixing method reduces energy consumed in a fixing step in an electrophotographic image forming apparatus. A photopolymerization composition is coated on an unfixed toner image formed on a recording medium. Then, the photopolymerization composition is irradiated with light, which does not have an emission wavelength band in a far infrared range and which has a maximum emission wavelength of 360 nm or longer to 420 nm or shorter, by using an LED, whereby the photopolymerization composition is cured and the unfixed toner image is fixed to the recording medium.

Abstract: A developer bearing member includes a base body, a surface layer, and a plurality of concave portions provided on the surface layer, wherein a resistance value of the surface layer is 102 ?·cm to 108 ?·cm, the number of the concave portions per unit area is 2250/mm2 to 12254/mm2, a major diameter of an opening of the concave portion is 8 ?m to 20 ?m, a depth of the concave portion is 2 ?m to 5 ?m, a dimensional tolerance of the major diameter is 0.5 ?m or less, and a dimensional tolerance of the depth is 0.5 ?m or less.

Abstract: In an image forming apparatus that outputs a reference clock, divides the outputted reference clock based on a set multiple, and generates an image clock based on the division, a width of a synchronization signal that indicates dynamic deviation characteristics is detected, and the multiple is set in accordance with the detected width of the synchronization signal.

Abstract: In an image forming apparatus that outputs a reference clock, divides the outputted reference clock based on a set multiple, and generates an image clock based on the division, a width of a synchronization signal that indicates dynamic deviation characteristics is detected, and the multiple is set in accordance with the detected width of the synchronization signal.

Abstract: In a laser beam printer, automatic optical quantity (APC) control is performed based on an optical quantity detection output to generate a laser beam having a predetermined quantity of light. In each scanning cycle, APC is effected by utilizing a period (unblanking period) in which the laser device is forcibly actuated to generate a horizontal synchronization signal. The unblanking period may be changed according to the print paper size or image formation/non-image-formation periods. Also, light quantity control may be effected through a plurality of scanning cycles before image formation and may be effected by utilizing the unblanking period during the period corresponding to the intervals of print sheets. Techniques also provided to prevent a transfer unit from being contaminated by toner images formed as a byproduct of APC.

Abstract: An image forming apparatus includes a light beam generator for generating a light beam, a rotational polygon mirror for scanning the light beam generated by the light beam generator across a member to be illuminated, a rotation detector for detecting whether or not the rotational polygon mirror rotates at a predetermined rotation number for an image formation, and a determining device for determining whether or not the rotational polygon mirror rotates at the predetermined rotation number stably in accordance with an output from the rotation detector.

Abstract: A hybrid type image forming apparatus capable of forming a high quality image by using two image forming units having different resolution from each other, perform high throughput image forming by selecting most suitable image forming method or methods depending upon a kind of input image data, and reducing its running cost. In the apparatus, input image data of resolution of 300 dpi is separated into monochromatic image data and color image data. The monochromatic image data is converted into that of 600 dpi so that four pixels of an image of 600 dpi make one pixel of an image of 300 dpi. Then, a monochromatic image is formed on the basis of the monochromatic image data of 600 dpi by the image forming unit employing the electrophotograph method. A print medium on which the monochromatic image is formed is conveyed to the image forming unit employing the ink-jet printing method where a color image is formed on the basis of the color image data of 300 dpi.

Abstract: An image forming apparatus which converts character or pattern information into bit map information (pixel information) and forms an image based thereon. The image forming apparatus includes a light-beam generator for generating a modulated light beam, a light-beam deflector for scanning an image carrier, a device for feeding a sheet to registration rollers and a driver for driving the image carrier. A time period is provided to operate the light-beam deflector and the feeding device before the driver starts to drive the image carrier to form an image.

Abstract: An image forming apparatus comprises image information which outputs a sync signal and means generated image information synchronously with the sync signal; image forming means form an image on the basis of the image information at either one of a plurality of resolutions and which generates a sync request signal to request a transmission of the sync signal; and a resolution changeover means. When the image forming unit received the resolution change over request signal before the sync request signal is generated, the image forming unit executes the switching operation of the resolution, and if the image forming unit received the resolution changeover request signal after the sync request signal had been generated, the image forming unit does not execute the switching operation of the resolution.

Abstract: An image forming apparatus for scanning a light beam modulated in accordance with image information using a rotational polygon mirror comprises a light beam generator for generating the light beam, an adjuster for adjusting the light quantity of the light beam generated by the light beam generator, a driver for driving the rotational polygon mirror in rotation, and a detector for detecting whether the rotational number of the rotational polygon mirror reaches a predetermined rotation number within a predetermined time. The light quantity adjuster starts the light quantity adjustment after the start of driving of the rotational polygon mirror with the driver, and before the rotation number of the rotational polygon mirror reaches the predetermined rotation number.

Abstract: An image forming apparatus includes a feeder means and a recorder. The feeder feeds a sheet of recording paper to a predetermined position in response to a spare paper feed signal instructing the feeding of the sheet of recording paper to the predetermined position preliminarily, and then feeds the sheet of recording paper being stopped at the predetermined position again in response to a record request signal. The recorder records an image on the sheet of recording paper fed by the feeder means through an electrophotographic process. The recorder means starts preparation to execute the electrophotographic process upon receiving the spare paper feed signal. As a result throughput is increased without causing other problems.

Abstract: An image forming apparatus for adjusting image density includes an input device for inputting a plurality of image type information and a discriminating device for discriminating the image type information in accordance with a signal other than a signal to be recorded. An image forming circuit, such as a printer, forms an image on the basis of image type information. A density adjusting circuit adjusts the image forming density of the image forming circuit in accordance with the input image type information. The discriminating device inputs a signal indicative of whether the input image type information indicates a text image or a graphics image, or whether it denotes Japanese or a European language (e.g., English). The discriminating device also inputs a signal indicative of the kind of font included in the input image type information or a signal indicative of a resolution for an output image to be formed by the printer.

Abstract: An image forming apparatus which can adjust a density comprises: a first input device to input image information; a second input device to input the kind of image information; an image forming circuit such as a printer form an image on the basis of image information which can vary an image forming density; and a density adjusting circuit to adjust the image forming density of the image forming circuit in accordance with the kind of input image information. The second input device inputs a signal indicative of whether the input image information indicates a text image or a graphics image or whether it denotes Japanese or European/English language. The second input device inputs a signal indicative of the kind of font included in the input image information or a signal indicative of a resolution of an output image which is formed by the printer.

Abstract: An image forming apparatus comprises image information which outputs a sync signal and generated image information synchronously with the sync signal; an image forming apparatus forms an image on the basis of the image information at either one of a plurality of resolutions and which generates a sync request signal to request a transmission of the sync signal; and a resolution changeover means.When the image forming unit received the resolution change over request signal before the sync request signal is generated, the image forming unit executes the switching operation of the resolution, and if the image forming unit received the resolution changeover request signal after the sync request signal had been generated, the image forming unit does not execute the switching operation of the resolution.

Abstract: In a laser beam printer, automatic optical quantity (APC) control is performed based on an optical quantity detection output to generate a laser beam having a predetermined quantity of light. In each scanning cycle, APC is effected by utilizing a period (unblanking period) in which the laser device is forcibly actuated to generate a horizontal synchronization signal. The unblanking period may be changed according to the print paper size or image formation/non-image-formation periods. Also, light quantity control may be effected through a plurality of scanning cycles before image formation and may be effected by utilizing the unblanking period during the period corresponding to the intervals of print sheets. Techniques also provided to prevent a transfer unit from being contaminated by toner images formed as a byproduct of APC.

Abstract: An image forming apparatus comprises includes a feeder means and recorder. The feeder feeds a sheet of recording paper to a predetermined position in response to a spare paper feed signal instructing the feeding of the sheet of recording paper to the predetermined position preliminarily, and then feeds the sheet of recording paper being stopped at the predetermined position again in response to a record request signal. The recorder records an image on the sheet of recording paper fed by the feeder means through an electrophotographic process. The recorder means starts preparation to execute the electrophotographic process upon receiving the spare paper feed signal. As a result, throughput is increased without causing other problems.

Abstract: A driver IC for driving a light source comprises means for generating a constant current, switching means for switching the constant current supplied to the light source, first input terminal for inputting a first signal to modulate a light emitted by the light source, said switching means performing a switching operation in accordance with the first signal, and second input terminal for inputting a second signal so as to supply the constant current to the light source, irrespective of the first signal.

Abstract: A communication system includes a main control unit controlling a plurality of units, a transmitter for transmitting information between the main control unit and the plurality of units, and an error detector. The error detector can include a modulator and demodulator for modulating or demodulating the transmitted information on the basis of a predetermined rule. The error detector detects a communication error in the transmitted information in accordance with the predetermined rule. Alternatively, the error detector can include a transmitted data creator/analyzer for creating data based on the transmitted information in a state in which the information contains positive data and negative data of the same bit in one frame and analyzes data when the data is received. This error detector detects a communication error in the transmitted information on the basis of the comparison between the positive and negative data.