Abstract: An image forming apparatus, includes: an image carrier that carries a developer image by a charge layer provided on a surface of the image carrier; a charger that charges the image carrier; a feeder that feeds the charger with a charge; a total charge amount detector that detects the total amount of the charge output by the feeder; an unsupplied charge amount calculator that calculates the amount of the charge output by the feeder but not supplied to the charger; and a layer thickness calculator that calculates the thickness of the charge layer based on the unsupplied charge amount calculated by the unsupplied charge amount calculator and the total charge amount detected by the total charge amount detector.

Abstract: A light-emitting device driver that includes a driver unit that drives a light-emitting device, a compensator that compensates for at least one of the rising and falling responses of the driver unit, a switching unit that switches on and off the compensator, and a control unit that performs on/off control on the switching unit.

Abstract: An image forming apparatus including a photoreceptor that rotates, a charging member provided in contact with or in close proximity of the photoreceptor to charge the photoreceptor, a charge amount detecting portion that accumulates current flowing across the photoreceptor to obtain a charge amount of the photoreceptor, while the current is being applied from the charging member until a voltage on a surface of the photoreceptor substantially corresponds to the voltage applied by the charging member, and a controller that calculates a film thickness of the photoreceptor based on the charge amount.

Abstract: A light-emitting device driver that includes a driver unit that drives a light-emitting device, a compensator that compensates for at least one of the rising and falling responses of the driver unit, a switching unit that switches on and off the compensator, and a control unit that performs on/off control on the switching unit.

Abstract: In view of realizing higher resolution in the sub-scanning direction and achieving high precision and high quality image formation without generating ununiform distribution of exposure, a scanning surface of a photosensitive material is scanned with an optical beam on sequential parallel linear scanning lines with a predetermined angle for the main scanning direction to form an exposed image thereon.

Abstract: Multi-value character (line image) data, characteristic information and half-tone data are stored while the memory is effectively used. Half-tone data is outputted from the attribute separating section 20. Vector pixels or the density data of 5 bits and the characteristic flag of 3 bits are outputted from the resolution converting section 12 and the edge detecting section 13. After a discriminating flag (1 bit) has been added to them by the data mixing section 21, they are formatted in a predetermined manner and stored in the memory M. In this case, both halftone data and vector pixels are stored as raster data of 9 bits. Further, the characteristic flag is stored as a portion of the vector pixels. Accordingly, the memory M is not wasted, and it is not necessary to separately provide a memory exclusively used for the characteristic flag.

Abstract: To form an exposed image with striking contrast on photosensitive material and form a high definition and high quality image, a first beam modulated according to an image signal and a second beam modulated according to an inverted image signal generated by inverting this image signal with smaller deelectrification effect than the first beam are synthesized on the photosensitive material.

Abstract: A period determination signal is generated in accordance with the image type of an input image signal. A clock signal having one of a plurality of periods is generated in accordance with the period determination signal. A CR integration circuit having a resistor and at least one capacitor generates a triangular-wave signal based on the clock signal. The combined capacitance of the CR integration circuit is changed in accordance with the period determination signal. A pulse-width modulated binary image signal is produced by comparing the triangular-wave signal with the input image signal. The amplitude of the triangular signal is kept constant by changing the combined capacitance of the CR integration circuit in proportion to the period of the clock signal.