Pioneer Corporation

Nippon Precision Circuits Inc.

Pioneer Micro Technology Corporation

Yoshihiro Hanada

Minoru Takeda

Akira Toyama

Kiyoshi Tateishi

Michiaki Nakamura

An image forming apparatus that displays an image, includes: a scanning section that scans light from a light source in a main scanning direction and a sub-scanning direction orthogonal to the main scanning direction, as drawing sine waves; a detecting part that detects a change in a position of the scanning part in the main scanning direction and a change in a position of the scanning part in the sub-scanning direction; a phase difference comparator that detects a phase difference and a frequency ratio between the main scanning direction and the sub-scanning direction, based on the change in the position of the main scanning direction and the change in the position of the sub-scanning direction; and an image data generation part that estimates a scanning trajectory of the scanning part based on the phase difference and the frequency ratio, and generates pixel data corresponding to the scanning trajectory.

Image forming apparatus

A light amount detecting apparatus includes: a photoelectric converting element converting quantity of light inputted to current; a current/voltage converting device having a positive input terminal connected to a first terminal of the photoelectric converting element, a negative input terminal connected to a second terminal of the photoelectric converting element, a negative output terminal for reversing polarity of a current inputted to the positive input terminal and outputting it as a voltage, a positive output terminal for reversing polarity of a current inputted to the negative input terminal and outputting it as a voltage, a first negative feedback resistor connecting the positive and negative output terminals, and a second negative feedback resistor connected between the negative and positive output terminals, the current/voltage converting device setting the photoelectric converting element in zero bias and converting the converted current to the voltage; and an amplifying device for amplifying the converted voltage.

Light amount detecting apparatus, and light amount information processing apparatus

A two-dimensional light scanning apparatus includes: a deflector to drive at a resonance frequency in a main scanning direction and a sub-scanning direction different from the main scanning direction; a position sensor to detect a scanning position of the deflector; a resonance frequency predicting part to predict the resonance frequency of the deflector; and a deflector drive control part to: for drawing a Lissajous figure in which scanning trajectories of the deflector do not overlap with each other for one frame, store a plurality of pairs of respective frequency ratios of driving signals in the sub-scanning direction to driving signals in the main scanning direction, and respective phases of the driving signals in the sub-scanning direction with respect to the driving signals in the main scanning direction; select one pair of a frequency ratio and a phase; and control the deflector with a driving signal.

Two-dimensional light scanning apparatus

Delta sigma D/A converter

An improved delta sigma digital-to-analog converter in which the thermometer code, which is output from a thermometer code converter, is divided into P blocks for every Q bits. An arrangement of the blocks is shifted in rotation by a barrel shifter at a frequency fs. Along with this, an arrangement of bits within each block is shifted in rotation by a shift register at a frequency of Q times fs. The bits within the code thus obtained are provided to local DACs, each specified to correspond to each of the given bits. In this manner, it is possible to maintain a lower operating frequency while at the same time to reducing the distortion in the output caused by a change in shifting the data in rotation in the local DACs, which change occurs depending on bit levels of the data in a form of the thermometer code.

Delta sigma digital-to-analog converter

A delta-sigma D/A converter has a quantizer, a thermometer code converter portion, and an odd/even bit-interchanging portion. The quantizer produces a first digital signal. The thermometer code converter portion and odd/even bit-interchanging portion divide the output level of the first digital signal such that it is represented by the sum of the output levels of second and third digital signals. Each of the second and third digital signals has an output level obtained by dividing the output level of the first digital signal by a factor of 2 or an integer close to it. During the former half of each sampling interval, first and second adders produce, respectively, a level signal corresponding to the second digital signal and an inverted level signal corresponding to an inversion of the third digital signal. During the latter half of the sampling interval, the adders produce, respectively, a level signal corresponding to the third digital signal and an inverted level signal corresponding to an inversion of the second digital signal. An operational amplifier subtracts the inverted level signal from the level signal and produces an analog signal corresponding to the output level of the first digital signal.

Growing community of inventors

Yokohama, Japan

Yoshihiro Hanada