Abstract: An image forming apparatus includes: a pseudo-halftone processing unit that processes input image data to output image data of first resolution; a resolution converting unit that converts the image data of the first resolution into image data of second resolution that is higher than the first resolution; a modulation-signal generating unit that generates a modulation signal obtained by modulating the image data of the second resolution according to a clock signal; and a light-source driving unit that drives a light source according to the modulation signal. The pseudo-halftone processing unit converts a region of pixels having the same pixel value into a parallel line pattern that is formed with a plurality of parallel lines oblique relative to a direction of arrangement of pixels. The resolution converting unit generates the image data o in which each edge of the lines forming the parallel line pattern is smoothed.

Abstract: A light source drive circuit for driving a light source is disclosed including a drive current generating unit generating a drive current, the drive current including a predetermined current for obtaining a predetermined light amount from the light source, a first auxiliary current input to the light source prior to input of the predetermined current, and a second auxiliary current added to the predetermined current in synchronization thereto; and a signal generating unit generating a first signal and a second signal, the first signal causing the first auxiliary current to be input for a first period and the second signal causing the second auxiliary current to be applied to the predetermined current for a second period. The first period is shorter than a period from a rise of the predetermined current to when a light amount from the light source reaches the predetermined light amount with the predetermined current.

Abstract: An image forming apparatus forms an image by irradiating light from a light source to an image carrier. The image forming apparatus includes: an image processing unit that processes image data at resolution N; and a control unit that generates modulation data to drive the light source at resolution m×N (m is a positive integer equal to or larger than 2), which is higher than the resolution N, based on the processed image data. Processing at the image processing unit is pseudo-halftone processing to perform line thinning or thickening on a part of the image data. The control unit converts the image data at the resolution N that has been subjected to the pseudo-halftone processing into data at the resolution m×N, and adjusts an amount of light for a part of the image data based on the resolution m×N.

Abstract: An image forming apparatus for forming an image by scanning an image bearer with light modulated in accordance with image information includes a light source configured to emit the light and a control device configured to control the light source in accordance with the image information. The control device sets light emission duration of the light source for forming a particular pixel in the image to be shorter than light emission duration of the light source for forming a normal pixel, which is a pixel other than the particular pixel irk the image, and sets light emission intensity of the light source for forming the particular pixel to be higher than light emission intensity of the light source for forming the normal pixel.

Abstract: An image forming apparatus includes: a pseudo-halftone processing unit that processes input image data to output image data of first resolution; a resolution converting unit that converts the image data of the first resolution into image data of second resolution that is higher than the first resolution; a modulation-signal generating unit that generates a modulation signal obtained by modulating the image data of the second resolution according to a clock signal; and a light-source driving unit that drives a light source according to the modulation signal. The pseudo-halftone processing unit converts a region of pixels having the same pixel value into a parallel line pattern that is formed with a plurality of parallel lines oblique relative to a direction of arrangement of pixels. The resolution converting unit generates the image data o in which each edge of the lines forming the parallel line pattern is smoothed.

Abstract: An apparatus includes an image-processing-unit that generates tag information indicating whether each of pixels of a first-resolution image data is a pixel of a character or a line, a resolution-converting-unit that converts the first-resolution image data to image data with a second resolution higher than the first resolution, and a light-source-driving-unit that drives light-source according to the second-resolution image data. The resolution-converting-unit includes an image-matrix-acquiring-unit that acquires an image matrix being image data and tag information with the first resolution in an area containing a target-pixel and pixels around the target-pixel, a pattern-matching-unit that determines whether the target-pixel is a pixel of an edge of a character or a line based on the image matrix, and a first-converting-unit that, when the pixel is the edge pixel, converts the image data to image data with the second resolution of a pattern determined in accordance with a layout of the target-pixel.

Abstract: An image forming apparatus that forms an image according to light emitted from a light source is provided. The image forming apparatus includes: a first image processor that performs image processing on image data having a first resolution and outputs the resulting image data; a resolution converter that acquires the image data having the first resolution output from the first image processor and converts the image data to image data having a second resolution that is higher than the first resolution; a modulation signal generator that modulates the image data having the second resolution according to a clock signal to thereby generate a modulation signal; a light source driver that drives the light source according to the modulation signal; and a second image processor that performs image processing on the image data having the second resolution to be modulated to the modulation signal.

Abstract: A light source drive device includes a first current source which provides a predetermined current to a light source corresponding to a predetermined light output, and a second current source which provides an overshoot current to the light source synchronized with the predetermined current. A processor is configured to set an overshoot time during which the overshoot current is provided to the light source. Further, an overshoot current is set which is applied to the light source. The overshoot time is set so that the overshoot time based on the rising of the predetermined current to when a light emission of the light source is detected.

Abstract: A range finder which irradiates a subject by emission of a light source, and receives reflected light from the subject so as to measure a distance to the subject, the range finder includes a plurality of light-source-driving circuits supplying a driving current to the light source when a light-emitting signal that controls the emission of the light source is input, wherein the light-emitting signal is output to one of the light-source-driving circuits, and each of the light-source-driving circuits has a different response speed to the light-emitting signal.

Abstract: An image forming apparatus includes a drive signal generating unit that generates a drive signal for driving a light source based on a reference pulse signal serving as a reference to form a plurality of pixels arranged in the main-scanning direction of an image, and the drive signal generating unit generates the drive signal by adjusting the pulse width of the reference pulse signal so that the amplitude of portions of the reference pulse signal with the adjusted pulse width corresponding to specific pixels among the pixels is larger than the amplitude of portions corresponding to normal pixels that are pixels other than the specific pixels among the pixels, and so that the pulse width of the portions of the reference pulse signal with the adjusted pulse width corresponding to the specific pixels is smaller than the pulse width of the portions corresponding to the normal pixels.

Abstract: An image forming apparatus that forms an image according to light emitted from a light source is provided. The image forming apparatus includes: a first image processor that performs image processing on image data having a first resolution and outputs the resulting image data; a resolution converter that acquires the image data having the first resolution output from the first image processor and converts the image data to image data having a second resolution that is higher than the first resolution; a modulation signal generator that modulates the image data having the second resolution according to a clock signal to thereby generate a modulation signal; a light source driver that drives the light source according to the modulation signal; and a second image processor that performs image processing on the image data having the second resolution to be modulated to the modulation signal.

Abstract: A light source drive circuit which drives a light source is disclosed, including a drive current generating unit which generates a drive current, the driving current including a predetermined current for obtaining a predetermined light amount from the light source; and first and second overshoot currents which are applied to the predetermined current in synchronization thereto; and a control unit which sets, to the drive current generating unit, a value of the first overshoot current to a fixed value, and a value of the second overshoot current in accordance with a light amount output from the light source.

Abstract: An image forming apparatus includes: a light source; and a light source control unit that supplies a pulse drive current according to image data to the light source. An amplitude of a part of the drive current corresponding to a specified pixel of the image data is larger than an amplitude of a part of the drive current corresponding to a normal pixel of the image data that is a pixel other than the specified pixel and the pulse width of the part of the drive current corresponding to the specified pixel is smaller than the pulse width of the part of the drive current corresponding to the normal pixel.

Abstract: A light source driving device which drives a plurality of light emitting parts provided in a light source to emit a plurality of light beams based on image information, includes a plurality of driving circuits configured to drive the plurality of light emitting parts. Each of the driving circuits includes a signal generation circuit that generates a modulation signal to control a light emitting intensity of the corresponding light emitting part based on the image information, a detection circuit that detects a light emitting status of the corresponding light emitting part; and a light emitting circuit that outputs a driving signal to the corresponding light emitting part to emit a light beam in accordance with the modulation signal and adjustment data obtained based on the light emitting status of at least one of the plurality of light emitting parts.

Abstract: An image forming apparatus includes: a pseudo-halftone processing unit that processes input image data to output image data of first resolution; a resolution converting unit that converts the image data of the first resolution into image data of second resolution that is higher than the first resolution; a modulation-signal generating unit that generates a modulation signal obtained by modulating the image data of the second resolution according to a clock signal; and a light-source driving unit that drives a light source according to the modulation signal. The pseudo-halftone processing unit converts a region of pixels having the same pixel value into a parallel line pattern that is formed with a plurality of parallel lines oblique relative to a direction of arrangement of pixels. The resolution converting unit generates the image data o in which each edge of the lines forming the parallel line pattern is smoothed.

Abstract: There provided is a semiconductor laser control device which including plural light sources that are configured with eight or more semiconductor laser elements, a one detecting section that detects a light power of the light sources, a light power control unit that compares a signal according to a light power detected by the detecting section with a control signal corresponding to a predetermined light power to control a current supplied to the light sources, and a voltage clamp circuit that functions as an overvoltage preventing means for the detecting section when turning on each of the light sources to perform light power control.

Abstract: An image forming apparatus is disclosed, including a light source; a drum; an optical scanning apparatus; and an endless belt. The image forming apparatus further includes a pattern forming unit which forms, on the endless belt along a conveying direction of the endless belt, a density fluctuation detecting pattern having a period; a density sensor which detects the density fluctuating detecting pattern and outputs a density signal including information on density fluctuations in the conveying direction of the endless belt; and a period detecting sensor which detects the period included in the density fluctuations.

Abstract: An image forming apparatus for forming an image in accordance with light to be emitted from a light source includes: a digital half-toning unit configured to convert a uniform-pixel-value region of image data to a parallel-line pattern formed with a plurality of parallel lines extending obliquely with respect to a direction, in which pixels are arrayed, thereby expressing each gray level of the image data as an area percentage; a modulated-signal generating unit configured to generate a modulated signal by modulating the converted image data with a clock signal; a light-source driving unit configured to drive the light source according to the modulated signal; and an edge control unit configured to narrow a to-be-illuminated region, which is to be illuminated by the light from the light source, in each of edge neighborhoods of the lines constituting the parallel-line pattern, while increasing intensity of the light.

Abstract: A light source driving circuit that drives a light source includes a driving electric current generator that generates a driving electric current including a predetermined electric current, a first auxiliary current, and a second auxiliary current; and a controller that sets values of the first and second auxiliary currents by using first and second lighting pattern signals, wherein each of the first and second lighting pattern signals is for controlling supply of the predetermined electric current to the light source. After setting a first value of the first auxiliary current, a second value of the second auxiliary current is set by using the second lighting pattern signal that defines a time period for stopping supply of the predetermined electric current to be shorter than a time period for stopping the supply of the predetermined electric current that is defined by the first lighting pattern signal.

Abstract: A light source drive circuit which drives a light source is disclosed, including a drive current generating unit which generates a drive current, the driving current including a predetermined current for obtaining a predetermined light amount from the light source; and first and second overshoot currents which are applied to the predetermined current in synchronization thereto; and a control unit which sets, to the drive current generating unit, a value of the first overshoot current to a fixed value, and a value of the second overshoot current in accordance with a light amount output from the light source.