Patent application number | Description | Published |
20080252787 | ANALOG PROCESSING CIRCUIT, ANALOG INTEGRATED CIRCUIT DEVICE, IMAGE READING DEVICE, AND IMAGE FORMING APPARATUS - A first clamping unit clamps a base voltage of an input image signal to a predetermined reference voltage. A sampling-and-holding unit samples and holds the image signal after clamping or a reference signal that becomes the base voltage of the image signal. An amplifying unit amplifies the image signal sampled and held by the sampling-and-holding unit. An analog-to-digital converting unit converts the image signal after amplification into a digital image signal. A second clamping unit clamps the reference signal to a predetermined voltage. | 10-16-2008 |
20080297616 | IMAGE READING DEVICE AND IMAGE READING METHOD - In an image reading device, a sampling-and-holding circuit generates a plurality of analog image signals by sampling an image signal at each sampling-and-holding timing and holding sampled image signals for a predetermined amount of time, an analog-to-digital converting unit converts the analog image signals into a plurality of digital image signals at each sampling-and-holding timing, a phase regulating unit performs phase regulation of each sampling-and-holding timing based on corresponding digital image signals to obtain phase-regulated sampling-and-holding timing. The sampling-and-holding circuit generates the analog image signal at each phase-regulated sampling-and-holding timing. | 12-04-2008 |
20090059324 | SIGNAL GENERATOR, IMAGE READING DEVICE, AND IMAGE FORMING APPARATUS - A clock-signal generating unit generates temporally-continuous clock signals. A spread-spectrum clock-signal generating unit generates a spread-spectrum clock signal by modulating a frequency spectrum of a clock signal generated by the clock-signal generating unit. A signal delaying unit generates a fixed delay unaffected by a spread spectrum from the spread-spectrum clock signal generated by the spread-spectrum clock-signal generating unit, and delays a phase of the spread-spectrum clock signal based on an amount of the fixed delay. | 03-05-2009 |
20090213261 | TIMING GENERATOR AND IMAGE SCANNING APPARATUS - A clock output from a quartz oscillator is input to a timing generator via a spread spectrum clock generator that spreads the spectrum of the clock. The clock is multiplexed by a phase locked loop to generate pixel clocks having the same frequency as a pixel frequency. The pixel clock is input to a delay locked loop, which generates a multi-layer clock by dividing each cycle of the pixel clock by 60. Clock generating units select a required phase from the multi-layer clock, thereby generating a timing signal. The phase, the pulse width, and the output period of the timing signal are controlled as desired by setting appropriate values to a register. | 08-27-2009 |
20100142009 | IMAGE READING APPARATUS - When a light source is in off state, a gray level of image data on a pixel-by-pixel basis is generated as a first black level and an average of gray levels of a portion of the image data corresponding to optical black image portions of sensor chips is generated as a second black level. After that, when an image of an original is read, an average of gray levels of the black image data on a line-by-line basis is generated as a third black level. The first black level is subtracted from a gray level of the image data on a line-by-line basis (an offset correction), and a difference between the third black level and the second black level is added to a gray level of the image data after being subjected to the subtraction on a line-by-line basis. | 06-10-2010 |
20100231979 | IMAGE READING DEVICE, IMAGE READING METHOD, AND IMAGE FORMING APPARATUS - A reference-signal generating unit generates a reference signal for generating a driving signal to drive each unit of the image reading device. A frequency modulating unit modulates frequency of the reference signal, thereby generating a frequency-modulated reference signal. A driving-signal generating unit generates the driving signal from the frequency-modulated reference signal. A photoelectric converting unit converts an incident light into an analog image signal using the driving signal. An AD converting unit converts the analog image signal into a digital image signal. A correcting unit corrects the digital image signal by generating a correction signal for eliminating a noise superimposed on the digital image signal using the frequency-modulated reference signal and adding the correction signal to the digital image signal. | 09-16-2010 |
20130162870 | IMAGE SIGNAL PROCESSING APPARATUS, IMAGE SCANNING APPARATUS AND METHOD FOR PROCESSING IMAGE SIGNAL - A signal processing circuit | 06-27-2013 |
20130201373 | IMAGE PROCESSING APPARATUS AND METHOD - An image processing apparatus includes an amplifying unit for, during a main scanning line period, amplifying an analog image signal input from a photoelectric conversion element and outputting the signal; an A/D converting unit for analog/digital-converting the signal to digital image data and outputting the data; and a digital offset correcting unit for performing a low-pass filter calculation based on the data to obtain an average value, calculating, based on the average value, a digital correction value used for correcting the data to obtain a desired black offset level, and performing correction on the data using the value. The digital offset correcting unit compares the value to a threshold, reduces the value to be equal to or less than the threshold if the value is equal to or greater than the threshold and updates the value to the reduced value, and performs the low-pass filter calculation and calculates the value. | 08-08-2013 |