Ricoh Company, Ltd.

Takashi Michiyoshi

Tetsuro Tatebe

Koji Kawahata

Yasutoshi Hirano

A discharge waveform generating device includes a timing reference generation circuit, a timing adjustment circuit, a waveform pattern generation circuit, and a timing correction circuit. The timing reference generation circuit generates a discharge timing for generating, from image data, a discharge waveform of ink to print the image data, based on a line synchronization signal for synchronizing discharge operations of discharge nozzles to discharge ink. The timing adjustment circuit sets an adjustment value of the discharge timing. The waveform pattern generation circuit generates the waveform from the image data, based on outputs of the timing reference generation circuit and the timing adjustment circuit. The timing correction circuit causes the waveform pattern generation circuit to start generation of the waveform in a condition in which the waveform pattern generation circuit has not finished the generation of the waveform when the timing reference generation circuit receives the line synchronization signal.

Discharge waveform generating device, method of generating discharge waveform, and non-transitory recording medium storing program

An exposure device, which emits light according to a gray level of image data, includes plural light emitting element lines arranged at different positions in a sub scanning direction, a number of the light emitting element lines being a number of bits representing a number of gray levels. Each of the light emitting element lines includes plural light emitting elements arranged in a line in a direction parallel to a main scanning direction, the light emitting elements numbers of layers of organic electro-luminescence light emitting elements being the same. The numbers of layers of the organic electro-luminescence light emitting elements laminated in the light emitting element lines, which are arranged at different positions in the sub scanning direction, are different from each other.

Exposure device and image forming apparatus

A PWM signal generating circuit, printer, and PWM signal generating method are described. The PWM signal generating circuit includes: a single counter configured to count values expressed in N bits; and at least one arithmetic device configured to generate a PWM signal, each of the at least one arithmetic device including a pulse width data storage unit for storing N-bit pulse width data representing a pulse width of the PWM signal to be generated, and an adder for calculating a carry value from a most significant bit obtained when adding the count value and the pulse width data. A signal having a level corresponding to the carry value is output at every change in the count value so that the PWM signal having the pulse width of the pulse width data is generated.

PWM signal generating circuit, printer, and PWM signal generating method

The oscillating circuit () includes a variable frequency oscillating circuit () for generating a clock signal (CK) whose frequency increases in response to an up-signal (UP) and decreases in response to a down-signal (DOWN), the frequency going up and down continuously between an upper-limit frequency and a lower-limit frequency. An up/down control circuit () outputs the down-signal when a duration of a low level of the clock signal drops below a first delay time and outputs the up-signal when the duration exceeds a second delay time longer than the first delay time.

Oscillating circuit, DC-DC converter, and semiconductor device

An oscillation frequency control circuit configured to control a frequency of a second clock signal of an oscillation circuit generating and outputting the second clock signal having a frequency in response to an input control signal is disclosed. The oscillation frequency control circuit includes a frequency difference detection circuit unit configured to detect a difference between a frequency of a predetermined first clock signal input externally and the frequency of the second clock signal, and generate and output a signal indicating a result of the detection; and a frequency control circuit unit configured to control the frequency of the second clock signal so that the frequency of the second clock signal continually changes back and forth between a predetermined lower limit value and a predetermined upper limit value in response to the output signal from the frequency difference detection circuit.

Oscillation frequency control circuit, and DC-DC converter and semiconductor device having the same

An oscillation frequency control circuit controls a second oscillation circuit, which generates and outputs a second clock signal of a second frequency according to a received control signal, to control the second frequency. The oscillation frequency control circuit includes a frequency difference detection circuit unit configured to detect a difference between a predetermined first frequency of a first clock signal generated by an external first oscillation circuit and the second frequency, and generate and output an output signal indicating a detection result, and a frequency control circuit unit configured to control, according to the output signal of the frequency difference detection circuit unit, the second oscillation circuit to control the second frequency of the second clock signal to make an absolute value of the difference between the first frequency and the second frequency greater than a predetermined value.

Oscillation frequency control circuit, DC-DC converter including the oscillation frequency control circuit, and semiconductor device

In a color video signal processing method, color difference component signals are converted into RGB component signals by a digital to digital conversion so as to reduce a size of a processing unit used for the conversion. An analog composite signal is converted into analog color difference component signals. The analog color difference component signals are then converted into digital color difference component signals. The digital color difference component signals are converted into digital RGB component signals by a digital to digital conversion based on an approximation method. Finally, the digital RGB component signals are converted into analog RGB component signals. The digital-to-digital conversion may be performed in accordance with equations in which each factor is a fractional number having a denominator of a power of 2.

Color video signal processing method and apparatus for converting

The present invention provides a processing system capable of displaying images on a screen and moving the images on the screen in response to for example user input. The system displays images on, for example, a computer monitor or a video game monitor using an image display apparatus that includes a background screen control portion that provides image data for one or more background screens and which is capable of performing horizontal and vertical scrolling functions.

Growing community of inventors

Osaka, Japan

Takashi Michiyoshi