Sharp Kabushiki Kaisha Corporation

Masanori Mori

Akihiko Taniguchi

Yoshikado Yamada

Masakiyo Okuda

Atsushi Narukawa

Tamaki Mashiba

Junichi Kajiwara

Hideo Taniguchi

Yasushi Nakanishi

Yukio Nakai

Yoshiomi Hamano

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 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 sheet supplying device supplies a sheet to a sheet supplied apparatus which has a predetermined maximum size of the sheet capable of being supplied thereto. The sheet supplying device includes a movable cassette for placing the sheet thereon and movable to at least two transport positions so as to transport the sheet therefrom to the sheet supplied apparatus in at least two transparent directions, and a driving device, to which a driving order is given, for moving the movable cassette to at least two transport positions in response to the driving order. The sheet supplying device further includes a control device, to which the size of the sheet placed on the movable cassette is input, for stopping the driving motion of the driving device prior to the driving order if the input size of the sheet exceeds the maximum size when the movable cassette is moved.

Rotatable sheet supplying cassette and associated controller which may

An automatic exposure control device for use in a copying machine in which a light source for illuminating the light to an original document is controlled based on the signal representing the light amount of the original document sensed by a light senses. There are two kinds of HIGH level limiter for limiting the upper limit of the power supplied to the light source. The HIGH level limiters are selected depending on whether the amount of light of the light source has been raised sufficiently or not, whereby over exposure copy or foggy copy can be prevented.

Automatic exposure device

Growing community of inventors

Ayama, Japan

Masanori Mori