Canon Kabushiki Kaisha

Kouki Kuroda

Koji Suzuki

Jyoji Nagahira

Yoshiaki Takayanagi

Nao Nagashima

Tsuneki Inuzuka

Toshiaki Yagasaki

Hiroshi Ogawa

Joyji Nagahira

A data processing device capable of digital processing of analog data and obtaining analog output signals from the result of digital processing, without the use of analog-digital converters or digital-analog converters.

Data processing device having a D/A function

Adjustment of a gain and an offset of a data processing apparatus for controlling the operation of a copying machine or the like can be performed all at once without requiring adjustment of individual components making up the apparatus, such as an A/D converter. Changes in the gain and/or offset of the apparatus which occur with time can be compensated for. Data fetch and output can be efficiently performed.

Apparatus for correcting errors in a digital-to-analog converter

An analog-to-digital converter comprises an output generator for forming an output signal in response to application of a start signal; a comparator for comparing an analog signal, to be converted to a digital signal, with the level of the output signal formed by the output generator and for providing an output representing the time period from initiation of formation of the output signal to occurrence of a predetermined relation between the output signal and the analog signal; and a clock signal generator. The converter further comprises a digital computer that includes an output terminal from which the start signal is applied to the output generator and an input terminal for receiving the output from the comparator. The computer further includes a counter for counting the pulses produced by the clock signal generator from the time the start signal is applied from the output terminal until a time when the input terminal receives the output representing the aforesaid time period, and a digital signal generator for forming a digital signal corresponding to the output signal on the basis of the count of clock pulses by the counter.

Analog-digital converter

An electrostatic recording apparatus including an image former for forming an electrostatic latent image, a device for developing the formed image, and a device for applying a bias voltage to the developer device in accordance with an identification as to whether the original relates to a character image or a half tone image. The bias voltage applying device includes first and second voltage generators for generating different bias voltages, and a selector device for selecting between the first and second generators. The bias voltage applying device is operable, during a developing time, to apply the selected bias voltage to the developer device, and during a non-developing time, to apply thereto a bias voltage different from the bias voltage applied during developing.

Electrostatic recording apparatus including a controlled developer device

A temperature control apparatus for controlling, e.g., a fixing heater of a copying machine has a fuse resistor connected to the fixing heater through a power relay, a thermistor for detecting the surface temperature of a fixing roller heated by the fixing heater, abnormality timers for counting the ON time of the fixing heater and having different preset counts corresponding to different modes of the copying machine, and a control circuit for disconnecting the fuse resistor when the output from the thermistor indicates overheating or the ON time of the heater exceeds the preset count of the timer. Overheating of the heater is prevented with high reliability.

Temperature control apparatus for detecting an abnormality in a heater

A recording apparatus in which a control unit utilizes a copy counter for plural purposes. The control unit also achieves other features such as securer jam detection, a constant operation regardless of the frequency of commercial power supply, securer timing and temperature control with limited number of sensors.

Recording apparatus

An image forming device constracted with an image forming device, a memory device to store therein a plurality of programs for stable control of an image quality, and a device for selecting and executing one of the programs stored in the memory device. The image forming device is further provided with a humidity detection device, a temperature control device, and a control device to effect potential control.

Image forming device

There is disclosed an image forming apparatus capable of compensating for fluctuations in the image forming conditions thereby ensuring optimum image formation. The image forming apparatus is provided with a control for modifying outputs from a processor for image formation when the length of pause in the image formation operation of the processor exceeds a predetermined value.

Image forming apparatus with control for image forming conditions

An image forming device constructed with an image forming device, a memory device to store therein a plurality of programs for stable control of an image quality, and a device for selecting and executing one of the programs stored in the memory device. The image forming device is further provided with a humidity detection device, a temperature control device, and a control device to effect potential control.

An image formation apparatus has detection signal generator for generating an analog detection signal, reference signal generator for generating an analog reference signal of a reference level, A/D converter for converting the analog signal into a digital signal, and controller for causing the detection signal to be input to the A/D converter and putting out a desired control signal and for causing the reference signal to be input to the A/D converter and determining the then magnitude of the digital signal to thereby detect abnormality of the A/D converter.

Image formation apparatus having a diagnosing function

The invention provides an image formation apparatus having a photosensitive drum, primary and secondary chargers which are controlled by first and second high voltage transformers, respectively, a predischarge charger controlled by a predischarge high voltage transformer, a transfer charger controlled by a transfer high voltage transformer, an exposure lamp controlled by a light control circuit, a developing roller which receives a controlled bias voltage from an AC developing bias circuit, a surface potentiometer, and a microprocessor. In preliminary exposure, an original is exposed to light to form an electrostatic latent image on the photosensitive drum. The potential of this latent image is measured by the surface potentiometer so as to detect the potential of the original. Based on the potential of the original and hence a detected density of an image of the original, image formation conditions such as a development bias voltage, corona charge, and an original exposure voltage are corrected.

Image formation apparatus including means for detecting and controlling

An electrostatic recording apparatus has a sensor for detecting a surface potential of a photosensitive member on which an electrostatic latent image is formed and a controller for controlling a developing bias voltage in accordance with the detected surface potential. The developing bias voltage includes an A.C. component and a D.C. component which are selectively used in accordance with a latent image potential. The frequency of the A.C. developing bias and the magnitude of the D.C. developing bias are variable so that an optimum quality of image is reproduced.

Electrostatic recording apparatus

An image formation apparatus reproduces both an image of a text and a continuous tone image such as a photograph with excellent gradation. The AC bias voltage to be applied to a developing roller is controlled stepwise or continuously in accordance with the spatial frequency of an original.

Image formation apparatus

A surface potentiometer comprises a measuring electrode, a chopper for intermittently shielding the electric field between the measuring electrode and an object to be measured, a preamplifier circuit for converting an AC signal induced in the measuring electrode into a low impedance signal, and a printed substrate having the wiring pattern of the preamplifier circuit formed on one surface thereof and the electrode pattern of the measuring electrode formed on the other surface thereof.

Growing community of inventors

Tokyo, Japan

Kouki Kuroda