Sharp Kabushiki Kaisha Corporation

Akihiko Taniguchi

Yasushi Nakanishi

Hiroyuki Kageyama

Tetsunori Mitsuoka

Shunju Anzai

Tamaki Mashiba

Junichi Kajiwara

Hideo Taniguchi

Koichi Sumida

Masanori Mori

Yoshiyuki Nakai

Takahiro Fukunaga

Yoshiaki Ibuchi

Akira Tamagaki

Kiyoshi Inoue

Takao Horiuchi

Eiichi Shimizu

Yohichi Shimazawa

Haruyoshi Migita

Katsumi Nagata

Masashi Toyoda

Itsuro Kato

Atsuyoshi Nakayama

Kenichi Maeda

Kazuhiko Yamakawa

Yoshitaka Honda

Itsuro Katoh

Yoshiomi Hamano

Hiroki Kai

An image forming apparatus includes photoreceptor drums, a charger, an exposure unit, a developing unit, an intermediate transfer belt and a fixing unit for fixing a toner image to a recording medium. The fixing unit includes a fixing part and a pressing part. The fixing part has a fixing roller, a heating member and a fixing belt. The pressing part has a pressing roller. The heating member is arranged close to, and so as to cover, the outer peripheral side of the fixing roller, and formed with an opening. Both edges of the opening extending along the axial direction of the fixing roller, are positioned closer to the pressing part side than the center axis of the fixing roller is.

Fixing device including fixing belt and image forming apparatus using the same

A fixing device of belt fixing type is provided. A fixing device includes a connector to be connected to wires provided therein. The connector includes integrally primary-side wiring connector terminals to be connected to primary-side wires each leading to a heat generating resistor, and secondary-side wiring connector terminals to be connected to secondary-side wires including wires each leading to a heat generating element-side thermistor, the secondary-side wires flowing current smaller than the primary-side wires.

Fixing device, image forming apparatus, and method of connecting wires in fixing device

A fixing device of belt fixing type is provided. A heat generating member that is a heat generating source for heating a fixing belt has a heat generating layer composed of a resistance heat generating element that generates heat due to being energized. The resistance heat generating element includes a paper passing region heating section and a detecting section provided on an end portion in an axial direction of the heat generating member and electrically connected in parallel with the paper passing region heating section. Furthermore, in a vicinity of the detecting section, an overheat preventing element that suppresses energization to the resistance heat generating element when temperature of the detecting section reaches a predetermined value, is provided.

Fixing device and image forming apparatus including fixing device

An image processing apparatus is provided which can output an image from which only specific image information can be positively detected when the specific image information used to prohibit copying of image information is added to image data. The present invention includes a specific image information adding portion that adds specific image information representing a specific image to image data when image processing is performed for input image data and a specific image information setting portion that sets a color and/or number of the specific image information.

Image processing apparatus, program, and recording medium

A power supply deviceincluding: a current sourcefor supplying current to a load circuitwhich operates on the supplied current, and a power switch unitbetween the current sourceand the load circuitto control passage of current, wherein: the power switch unitincludes a switching elementconnected in parallel with the open-close element, a power supply controllerincluding an open-close element controllerwhich controls operation of the open-close elementand a switching element controllerwhich controls operation of the switching element, and a voltage detectorwhich detects terminal voltage of the load circuit; and the power switch unitturns on the switching element before supplying current to the load circuit and closes the open-close element when the terminal voltage of the load circuit becomes almost equal to supply voltage.

Power supply device preventing inrush current

A control circuit for outputting a signal for controlling an amount of light emitted from a plurality of light emitting elements. The control circuit includes a controller or CPU, and a D/A converter outputting a signal for setting a voltage in multiple gradation in accordance with a lighting state of the light emitting element. An amplifying circuit amplifies an output of the D/A converter and outputs an amplified output as a control signal. A reference voltage generating circuit generates a reference voltage and a comparator compares the control signal with the reference voltage. The controller varies an output of the D/A converter based on the result of comparison by the comparator, to adjust the output of the D/A converter so that the control signal is equivalent to the reference voltage. Accordingly each voltage is reset in the multiple gradation to allow the light emitting element to appropriately emit light based on the adjusted output. As a result, a plurality of light emitting elements can be controlled stably without using a high precision circuit element.

Light emitting element control device, optical sensor control device and

A paper feeding unit includes: a detecting board formed of a regular-polygonal prism having a multiple number of sensors; a detection block with sides which each have a multiple number of signal generating portions and are able to face the sensors; a holder portion holding the detection block so as to allow the posture of the block to be changed to fix the block at setup positions; and a display window which allows a paper-size indicator displayed on the signal generating portions of the detection block to be seen from the outside. In this configuration, the orientation and position of the detection block are adapted to be changed in accordance with the size of paper held in the paper feed cassette.

Paper feeding unit

In an image forming apparatus provided with a cooling fan for cooling an original table glass, a controller measures a cooling time from the end of a previous copying operation to the start of a current copying operation. An operating condition determining section estimates a residual amount of heat energy based on the measured time and the generated amount of heat energy at the pervious copying operation. An amount of heat energy to be generated at the current image forming is added to the thus estimated residual amount of heat energy. Based on the sum of the heat energy, actual temperature-rise characteristics are calculated. The fan is driven at a rotating rate for an operating time in accordance with the thus calculated temperature-rise characteristics.

Image forming apparatus with fan cooling

An image-quality stabilizer provided in a copying machine executes a feedback control on a charger output based on an adhering toner amount detected by a patch sensor in a pre-rotation of the photoreceptor drum directly before each copying operation is started. A time interval between feedback controls is counted by a timer, and a CPU sets an appropriate time interval in accordance with an amount of change in the adhering toner amount detected by the patch sensor or in accordance with the charger output before and after feedback control. According to the described arrangement, since the feedback control is executed at a timing set in accordance with the amount of change in adhering toner, variations in image quality such as an increase in image density caused by overcompensation and an excessive feedback control can be prevented, thereby ensuring stable image quality by efficiently compensating the image density without increasing an amount of toner consumption.

Image-quality stabilizer having adjustable time interval between

A copying machine having a zooming function, the copying machine including a first driving motor for scanning an optical reading system, a first control circuit for controlling the first driving motor, a second driving motor for driving an image forming section including a photosensitive body and for feeding copy paper, a second control circuit for controlling the second driving motor, a side eraser control circuit for controlling the side eraser and switches on a light of a corresponding LED in response to the magnification, and control means for outputting a speed control signal in response to the selected magnification to the first control circuit so as to control the scanning speed of the optical reading system, and outputting a control signal in response to the selected magnification to the side eraser circuit, and outputting a driving signal generated from the control signal to the second control circuit so as to control the second driving motor.

Copying machine having a zooming function

A copying machine having a plurality of blank lamps for removing charges on a non-used area of a photoconductor included in the copy machine for copying an original image includes a unit for generating a PWM signal having a variable pulse width, a unit for converting the PWM signal into a voltage signal based on the pulse width of the PWM signal and supplying the voltage signal, and a unit for controlling turning on and off of the blank lamps based on the voltage signal.

Copying machine

A copying timing counting system for counting the rotation angle of a photoreceptor drum in an electrophotographic copying machine comprises a pulse generator, and a pulse counter. The pulse counter is responsive to the pulse generator for counting both the pulse rising edge and the pulse falling edge. Since the counter can count both the pulse rising edge and the pulse falling edge, the resolving power of the photoreceptor drum can be doubled as compared with the detection system of either of the pulse rising edge or the pulse falling edge taken alone.

Copying process timing control system for electrophotographic copying

A heat fixing device for a image reproduction machine includes a heat roller having a heat source for heat fixing a toner image on a copy paper, a temperature sensing element for sensing the temperature of the heat roller, and a temperature control element responsive to the output of the temperature sensing element for controlling the power supply to the heat source. The temperature sensing element and the temperature control element are integrally combined.

Integrated assembly of thermostat and thermistor in fixing device of

An abnormal condition detection device for an automatically controlled light scanning device includes a light exposure lamp for emitting light toward an original mounted on an original table, a reflection plate for reflecting light from at least a portion of the original table, a sensor for receiving light reflected from the reflection plate, a plurality of comparators for detecting the amount of light received by the sensor, and a detection circuit for determining whether or not the amount of light detected by the comparators is within a predetermined normal range.

Light exposure lamp having abnormal condition monitor

An electrophotographic copying machine includes a control circuit, a combined display responsive to the control circuit for showing the number of one or more copied papers, and the position of any paper jam or the operation condition. The combined display utilizes figure segments illuminated to form any figure, silhouette segments of the figure segments illuminated to provide a silhouette of the copying machine, and position marks illuminated to indicate the position of trouble in the machine and its operation conditions.

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Osaka, Japan

Akihiko Taniguchi