Abstract: A high-voltage power supply for an image forming apparatus compares a detected output voltage generated by dividing a high-voltage output by a voltage dividing circuit with a control value to feedback control the high-voltage output and outputs a voltage that is to be applied to a member involved in image formation. The high-voltage power supply includes a printed circuit board on which a resistor connected to a high-voltage output side of the voltage dividing circuit is mounted. A slit including a first portion and a second portion is formed in the printed circuit board. The first portion extends across a straight line connecting terminals of the resistor. The second portion continues from the first portion and extends in a direction receding from one of the terminals of the resistor.

Abstract: A power supply apparatus outputs a developing voltage in which a pulse wave shape at a time of positive amplitude is different from a pulse wave shape at a time of negative amplitude. Voltages are supplied from two switching regulators respectively to a bridge circuit for driving a transformer. Here, an absolute value of a difference between a drive frequency of a first switching regulator and a drive frequency of a second switching regulator is configured to be not less than an invisible frequency at which a banding cannot be recognized by humans.

Abstract: A high-voltage power supply for an image forming apparatus compares a detected output voltage generated by dividing a high-voltage output by a voltage dividing circuit with a control value to feedback control the high-voltage output and outputs a voltage that is to be applied to a member involved in image formation. The high-voltage power supply includes a printed circuit board on which a resistor connected to a high-voltage output side of the voltage dividing circuit is mounted. A slit including a first portion and a second portion is formed in the printed circuit board. The first portion extends across a straight line connecting terminals of the resistor. The second portion continues from the first portion and extends in a direction receding from one of the terminals of the resistor.

Abstract: An image forming apparatus includes a photosensitive member, an exposure unit configured to expose the photosensitive member corresponding to an image, a developing unit configured to develop, using a toner, an electrostatic latent image formed on the exposed photosensitive member, a generation unit configured to generate a waveform signal for the developing unit, a parallel-to-serial conversion unit configured to apply, at a predetermined sampling period, parallel-to-serial conversion to a plurality of signals including the generated waveform signal, a serial-to-parallel conversion unit configured to apply, at the predetermined sampling period, serial-to-parallel conversion to the signals output from the parallel-to-serial conversion unit, and a voltage applying unit configured to apply to the developing unit a voltage composed of a direct-current voltage and an alternating-current voltage superimposed thereon based on the waveform signal among signals output from the serial-to-parallel conversion unit.

Abstract: A power supply apparatus outputs a developing voltage in which a pulse wave shape at a time of positive amplitude is different from a pulse wave shape at a time of negative amplitude. Voltages are supplied from two switching regulators respectively to a bridge circuit for driving a transformer. Here, an absolute value of a difference between a drive frequency of a first switching regulator and a drive frequency of a second switching regulator is configured to be not less than an invisible frequency at which a banding cannot be recognized by humans.

Abstract: An image forming apparatus capable of suppressing occurrences of image defects and maintaining the image density constant while improving the development ability. The image forming apparatus includes a photosensitive drum on which an electrostatic latent image is carried, a developing sleeve on which developer is carried, an AC high-voltage drive circuit, an AC transformer, a DC high-voltage circuit, a p-p voltage detection circuit, and a CPU. The p-p voltage detection circuit converts a peak-to-peak voltage across a capacitor into a DC voltage which is taken out as a capacity detection signal. Based on the capacity detection signal output from the p-p voltage detection circuit, the CPU changes an image formation condition, e.g., a set value of a developing bias voltage.

Abstract: An image forming apparatus includes a photosensitive member, an exposure unit configured to expose the photosensitive member corresponding to an image, a developing unit configured to develop, using a toner, an electrostatic latent image formed on the exposed photosensitive member, a generation unit configured to generate a waveform signal for the developing unit, a parallel-to-serial conversion unit configured to apply, at a predetermined sampling period, parallel-to-serial conversion to a plurality of signals including the generated waveform signal, a serial-to-parallel conversion unit configured to apply, at the predetermined sampling period, serial-to-parallel conversion to the signals output from the parallel-to-serial conversion unit, and a voltage applying unit configured to apply to the developing unit a voltage composed of a direct-current voltage and an alternating-current voltage superimposed thereon based on the waveform signal among signals output from the serial-to-parallel conversion unit.

Abstract: The conventional techniques cannot set optimal energy saving modes separately for a plurality of loads and can hardly attain further suppression of power consumption. To accomplish this, in an image forming apparatus including a main circuit board which has a master CPU and controls the operation of the entire image forming apparatus, and a plurality of sub circuit boards each have a slave CPU and control each corresponding control target, the operating condition of each slave CPU is stored in correspondence with the operation mode of the image forming apparatus, and, upon being notified of the operation modes of the image forming apparatus, the slave CPU of each of the plurality of sub circuit boards sets the operation status of the slave CPU by referring to the table of the operation modes.

Abstract: An image forming apparatus which can prevent degradation of image quality in a case where dot patterns for preventing the formation of image stripes are superimposed on respective developed images corresponding to image signals. Developed images are formed on a photosensitive drum using developers of respective different colors based on image information. The developed images formed on the photosensitive drum are transferred onto an intermediate transfer belt. For each of the developed images of the respective colors, a number of dot developed images which are minute dot-shaped images formed in a dispersed manner are transferred onto the intermediate transfer belt.

Abstract: An area signal generation unit and a logical operation circuit control a dot pattern forming unit which forms a dispersed dots image by dispersing dot developer images each having the area of at least one dot, so as not to form a dot pattern in the area of a patch image to be formed by a patch image forming unit or the sensing area of the patch image. An image forming apparatus capable of avoiding the influence of a dispersed dots image on a patch image with suppressing nonuniformity caused by a line-like image when forming a patch image for color stabilization control, is provided.

Abstract: An image forming apparatus capable of suppressing occurrences of image defects and maintaining the image density constant while improving the development ability. The image forming apparatus includes a photosensitive drum on which an electrostatic latent image is carried, a developing sleeve on which developer is carried, an AC high-voltage drive circuit, an AC transformer, a DC high-voltage circuit, a p-p voltage detection circuit, and a CPU. The p-p voltage detection circuit converts a peak-to-peak voltage across a capacitor into a DC voltage which is taken out as a capacity detection signal. Based on the capacity detection signal output from the p-p voltage detection circuit, the CPU changes an image formation condition, e.g., a set value of a developing bias voltage.

Abstract: An area signal generation unit and a logical operation circuit control a dot pattern forming unit which forms a dispersed dots image by dispersing dot developer images each having the area of at least one dot, so as not to form a dot pattern in the area of a patch image to be formed by a patch image forming unit or the sensing area of the patch image. An image forming apparatus capable of avoiding the influence of a dispersed dots image on a patch image with suppressing nonuniformity caused by a line-like image when forming a patch image for color stabilization control, is provided.

Abstract: A control board includes a main-board and a plurality of sub-boards which control loads. The sub-boards each include a providing unit which provides a board type ID, a read unit which reads an installation location ID, and a transmission unit which transmits the board type ID and the installation location ID to the main-board. The main-board includes a communication control unit, a configuration information acquisition unit which acquires configuration information expressed by a combination of the board type ID and the installation location ID, an analysis unit which analyzes the configuration information, and a control unit which controls the sub-unit on the basis of information analyzed by the analysis unit.

Abstract: An image forming apparatus that can maintain the accuracy of temperature control of an object to be heated within a predetermined range and avoid adverse effects of contamination of first temperature detection means. The image forming apparatus 1 has a photosensitive drum 14, a heater 901, a thermopile temperature sensor 902, a non-contact thermistor 903, and a control circuit 904. The control circuit 904 controls the heater 901 based on an output signal 902s in a case where the output signal 902s is output earlier in time than the output signal 903s, and informs of a state of the thermopile temperature sensor 902 in a case where the output signal 903s is output earlier in time than the output signal 902s.

Abstract: An image forming apparatus which can prevent degradation of image quality in a case where dot patterns for preventing the formation of image stripes are superimposed on respective developed images corresponding to image signals. Developed images are formed on a photosensitive drum using developers of respective different colors based on image information. The developed images formed on the photosensitive drum are transferred onto an intermediate transfer belt. For each of the developed images of the respective colors, a number of dot developed images which are minute dot-shaped images formed in a dispersed manner are transferred onto the intermediate transfer belt.

Abstract: The conventional techniques cannot set optimal energy saving modes separately for a plurality of loads and can hardly attain further suppression of power consumption. To accomplish this, in an image forming apparatus including a main circuit board which has a master CPU and controls the operation of the entire image forming apparatus, and a plurality of sub circuit boards each have a slave CPU and control each corresponding control target, the operating condition of each slave CPU is stored in correspondence with the operation mode of the image forming apparatus, and, upon being notified of the operation modes of the image forming apparatus, the slave CPU of each of the plurality of sub circuit boards sets the operation status of the slave CPU by referring to the table of the operation modes.

Abstract: An image forming apparatus that can maintain the accuracy of temperature control of an object to be heated within a predetermined range and avoid adverse effects of contamination of first temperature detection means. The image forming apparatus 1 has a photosensitive drum 14, a heater 901, a thermopile temperature sensor 902, a non-contact thermistor 903, and a control circuit 904. The control circuit 904 controls the heater 901 based on an output signal 902s in a case where the output signal 902s is output earlier in time than the output signal 903s, and informs of a state of the thermopile temperature sensor 902 in a case where the output signal 903s is output earlier in time than the output signal 902s.

Abstract: An image forming apparatus has a movable image bearing member, a image forming device for forming a developer image on the image bearing member, and an intermediate transfer member on which the developer image on the image bearing member is transferred while it is moving at a predetermined surficial moving speed different from the surficial moving speed of the image bearing member. The image forming apparatus forms a predetermined image prior to formation of a normal image.

Abstract: A control board includes a main-board and a plurality of sub-boards which control loads. The sub-boards each include a providing unit which provides a board type ID, a read unit which reads an installation location ID, and a transmission unit which transmits the board type ID and the installation location ID to the main-board. The main-board includes a communication control unit, a configuration information acquisition unit which acquires configuration information expressed by a combination of the board type ID and the installation location ID, an analysis unit which analyzes the configuration information, and a control unit which controls the sub-unit on the basis of information analyzed by the analysis unit.

Abstract: Provided is an image forming apparatus, including: a movable image bearing body; an image forming unit for forming a developer image on the image bearing body; a transferring unit for transferring the developer image formed on the image bearing body onto a moving transferring medium; and a control unit for controlling the image forming unit to form a predetermined image composed of a dot image with a predetermined density prior to formation of a normal image, in which a composite image is formed from the normal image and the predetermined image in an area where the normal image is to be formed, and the dot image is formed in a dot area having the normal image and the predetermined image overlapped with each other, with a density determined on the basis of a relationship between a density of the normal image and the predetermined density in the dot area.