Abstract: An image forming apparatus includes a power supply part that supplies electronic power in two different power modes (first and second modes), a communication part that includes a transmitting and receiving part that receives a network packet in the both modes, and a determination part that stores filter information and determines whether or not the network packet matches one of filter settings, a determination control part that performs a rewrite operation to repeatedly rewrite the filter information while running in the second mode, a power supply control part that transits the power mode of the power supply part from the second mode to the first mode based on a determination result of the determination part, a packet transmitting and receiving part that receives the network packet supplied from the transmitting and receiving part in the first mode and stops an operation of itself in the second mode, and an image forming part stops an operation of itself in the second mode.

Abstract: An image forming apparatus includes a power supply part that supplies electronic power in two different power modes (first and second modes), a communication part that includes a transmitting and receiving part that receives a network packet in the both modes, and a determination part that stores filter information and determines whether or not the network packet matches one of filter settings, a determination control part that performs a rewrite operation to repeatedly rewrite the filter information while running in the second mode, a power supply control part that transits the power mode of the power supply part from the second mode to the first mode based on a determination result of the determination part, a packet transmitting and receiving part that receives the network packet supplied from the transmitting and receiving part in the first mode and stops an operation of itself in the second mode, and an image forming part stops an operation of itself in the second mode.

Abstract: An image forming apparatus capable of realizing miniaturization of apparatus and low cost is supplied. In the image forming apparatus, an inputting section inputs gradation data values P with N bits; a gradation changing section changes the gradation data value P into a data set including 2(N?M) (M<N) data with M bits; and a pixel forming section receives the data sets each includes 2(N?M) (M<N) data with M bits according to an receiving order, forms dots whose energies are different on respective lines of M lines, and forms a gradation pixel of M bits.

Abstract: A power source device includes an oscillator generating a clock, a frequency division unit dividing the clock to output a pulse, a sequence generation unit generating sequences “N” with respect to each switching of the pulse, a frequency division ratio setting unit setting frequency division ratio, a switching element driven by the pulse, and a piezoelectric transformer outputting alternating high voltage from a secondary-side when a primary-side is applied with voltage. The generated sequence and the set frequency division ratio are compared to output the pulses of fractional-M, -M+1 frequencies. An average frequency division ratio of the pulses of fractional-M, -M+1 frequencies determined by (M×?)+(M+1)×?/(?+?), where ? and ? respectively represent the number of pulses of “M” and “M+1” per unit time. The average frequency division ratio and frequency division ratio become equal at a sequence generation cycle and approximated in a period shorter than the sequence generation cycle.

Abstract: A piezoelectric transformer driving device including: an oscillator; a frequency-divider outputting a pulse by dividing a clock signal from the oscillator by a frequency-divide ratio received thereto; a switching element driven by the pulse and intermittently applying a voltage to a primary side of a piezoelectric transformer; a frequency-divide ratio instructing unit holding a frequency-divide ratio instruction value of a real number having an integer part and an fractional part; a binarization unit binarizing the frequency-divide ratio instruction value into two different integer frequency-divide ratios and selectively outputting the frequency-divide ratios. The binarization unit adjusts an appearance ratio of the frequency-divide ratios such that an average of the frequency-divide ratios output from the binarization unit is equal to an average of the frequency-divide ratio instruction value.

Abstract: A piezoelectric transformer driving device including: an oscillator; a frequency-divider outputting a pulse by dividing a clock signal from the oscillator by a frequency-divide ratio received thereto; a switching element driven by the pulse and intermittently applying a voltage to a primary side of a piezoelectric transformer; a frequency-divide ratio instructing unit holding a frequency-divide ratio instruction value of a real number having an integer part and an fractional part; a binarization unit binarizing the frequency-divide ratio instruction value into two different integer frequency-divide ratios and selectively outputting the frequency-divide ratios. The binarization unit adjusts an appearance ratio of the frequency-divide ratios such that an average of the frequency-divide ratios output from the binarization unit is equal to an average of the frequency-divide ratio instruction value.

Abstract: A pseudo random number generating circuit forms uniform distribution random number noises. An insertion noise data forming unit receives the uniform distribution random number noises, center-distributes them around 0 as a center, further reads out output correction values of every recording device from an LED characteristics variation data memory, center-distributes them on the basis of the output correction values, and outputs them. A noise inserting circuit receives an output of the insertion noise data forming unit and adds it to input image data. The occurrence a stripe-shaped concentration variation on an output image is prevented, so that a good output image is obtained.

Abstract: A power source device includes an oscillator generating a clock, a frequency division unit dividing the clock to output a pulse, a sequence generation unit generating sequences “N” with respect to each switching of the pulse, a frequency division ratio setting unit setting frequency division ratio, a switching element driven by the pulse, and a piezoelectric transformer outputting alternating high voltage from a secondary-side when a primary-side is applied with voltage. The generated sequence and the set frequency division ratio are compared to output the pulses of fractional-M, ?M+1 frequencies. An average frequency division ratio of the pulses of fractional-M, ?M+1 frequencies determined by (M×?)+(M+1)×?/(?+?), where ? and ? respectively represent the number of pulses of “M” and “M+1” per unit time. The average frequency division ratio and frequency division ratio become equal at a sequence generation cycle and approximated in a period shorter than the sequence generation cycle.

Abstract: An image forming apparatus illuminates a pixel formation member with optical energy according to image data specifying a value for each pixel in the image. Some of the optical energy emitted to form a pixel is distributed over surrounding pixels; similarly, a pixel may receive peripheral optical energy that was emitted to form surrounding pixels. The amount of peripheral optical energy thus received is calculated, and the amount of optical energy emitted to form the pixel is adjusted to compensate for the peripheral optical energy, so that the total optical energy received by the pixel has the intended value. Image irregularities are thereby avoided, even if the image formation apparatus employs multiple light-emitting elements with different energy emission distributions.

Abstract: An image forming apparatus capable of realizing miniaturization of apparatus and low cost is supplied. In the image forming apparatus, an inputting section inputs gradation data values P with N bits; a gradation changing section changes the gradation data value P into a data set including 2(N?M) (M<N) data with M bits; and a pixel forming section receives the data sets each includes 2(N?M) (M<N) data with M bits according to an receiving order, forms dots whose energies are different on respective lines of M lines, and forms a gradation pixel of M bits.

Abstract: A printing apparatus for printing an image onto a recording medium based on input image data, comprises an electrostatic latent image carrier for forming an electrostatic latent image, and an exposure controller for forming the electrostatic latent image corresponding to one pixel upon exposure of the electrostatic latent image carrier with a combination of a plurality of different exposure amounts, wherein the exposure controller performs the exposure with the combination of the plurality of exposure amounts in a manner to satisfy a condition for an index value LNR expressed by a following general equation (1) using an optical density od (n) standardized on the condition of the maximum optical density equal to 1.0, identification information comb assigned to identify each combination of the plurality of exposure amounts, and the number of varieties m of a cumulative exposure amount used for modulation of the image data.

Abstract: A pseudo random number generating circuit forms uniform distribution random number noises. An insertion noise data forming unit receives the uniform distribution random number noises, center-distributes them around 0 as a center, further reads out output correction values of every recording device from an LED characteristics variation data memory, center-distributes them on the basis of the output correction values, and outputs them. A noise inserting circuit receives an output of the insertion noise data forming unit and adds it to input image data. The occurrence a stripe-shaped concentration variation on an output image is prevented, so that a good output image is obtained.

Abstract: A printing apparatus for printing an image onto a recording medium based on input image data, comprises an electrostatic latent image carrier for forming an electrostatic latent image, and an exposure controller for forming the electrostatic latent image corresponding to one pixel upon exposure of the electrostatic latent image carrier with a combination of a plurality of different exposure amounts, wherein the exposure controller performs the exposure with the combination of the plurality of exposure amounts in a manner to satisfy a condition for an index value LNR expressed by a following general equation (1) using an optical density od (n) standardized on the condition of the maximum optical density equal to 1.0, identification information comb assigned to identify each combination of the plurality of exposure amounts, and the number of varieties m of a cumulative exposure amount used for modulation of the image data.

Abstract: An image forming apparatus illuminates a pixel formation member with optical energy according to image data specifying a value for each pixel in the image. Some of the optical energy emitted to form a pixel is distributed over surrounding pixels; similarly, a pixel may receive peripheral optical energy that was emitted to form surrounding pixels. The amount of peripheral optical energy thus received is calculated, and the amount of optical energy emitted to form the pixel is adjusted to compensate for the peripheral optical energy, so that the total optical energy received by the pixel has the intended value. Image irregularities are thereby avoided, even if the image formation apparatus employs multiple light-emitting elements with different energy emission distributions.

Abstract: An ink jet printer has a printhead formed of a piezoelectric element having an electrical capacitance with a known temperature characteristic. A memory stores a reference temperature Tref and a reference capacitance Cref of the printhead measured at the reference temperature. A capacitance measuring section measures a capacitance Cm of the printhead at a temperature Te when the printer is in use. A temperature computing section computes the temperature Te on the basis of the reference capacitance Cref, the measured capacitance value Cm, and the reference temperature Tref. A table lists various values of the temperatures and corresponding values of the drive voltages. An optimum value is selected from among the values of the drive voltage listed in the table and is used for driving the printhead at the selected temperature.

Abstract: An ink jet printer has ink pressure chambers defined by opposed walls formed of a piezoelectric material. The walls distorts in shear mode to eject ink drops from the ink pressure chambers when voltages are applied to the walls in accordance with print data. A row of ink pressure chambers eject ink drops through orifices during printing operation. A second ink pressure chamber is in communication with the other ink pressure chambers. An ink-state detector provides a voltage to the second ink pressure chamber to measure the impedance of the ink between the walls of the second ink pressure chamber. The impedance reflects the remaining amount of remaining ink.