Minolta Camera Kabushiki Kaisha

Tsuneo Kitagawa

Kenji Shibazaki

Tomoji Murata

Kenichi Arai

Kenzo Nagata

Yoshiaki Takano

Masamichi Sugiura

Masazumi Ito

Tetsuo Matsushita

Shoji Kashiwagi

Takeshi Morikawa

Shoji Imaizumi

Kazuhiro Araki

Hiromitsu Saijo

Keiji Yoshida

Hiroyuki Kishimoto

Masakazu Sogame

An image forming apparatus according to the present invention is provided with a developing unit which develops an electrostatic latent image formed on an electrostatic latent image holding body. The image forming apparatus comprises a measuring device for measuring toner concentration in the developing unit, a toner container for storing toner, a first supply unit for supplying a predetermined amount of toner from the toner container to the developing unit when it is determined that the toner concentration measured by the measuring device is lower than a first predetermined concentration, a second supply unit for supplying from the toner container to the developing unit toner of a larger amount than the first supply unit, a storage device for storing predetermined information related to concentration when it is determined that the toner concentration measured by said measuring device is below a second predetermined concentration lower than the first predetermined one, and an actuating device for actuating the second supply unit if the predetermined information has been stored in said storage device when power is turned on.

Image forming apparatus improved in toner supply operation

An image forming apparatus maintaining the fixing temperature at a fixed level, by detecting the surface temperature of a heating roller provided internally with a heater in a fixing unit, and by controlling an on-time which starts upon the surface temperature reaching a predetermined temperature and ends when the heater is switched on and an off-time which starts upon the surface temperature reaching the predetermined temperature and ends when the heater is switched off. The on-time and off-time data are stored in a memory corresponding to use conditions such as ambient temperature and the type of paper to be used. Initially, an image fixing operation is executed in accordance with the data prestored in the memory, and transition of the surface temperature of the heating roller is detected which results from the image fixing operation. Data concerning new on-time and off-time are calculated on the basis of the detection result, and the calculation result is used as feedback for a next image fixing operation.

Image forming apparatus having a controlled fixing means

An image forming apparatus is provided with a developing unit for making a visible image out of an electrostatic latent image with use of developer. The apparatus has a determination unit for making a determination as to whether the developer is stored or not in the developing unit, a supply unit for supplying the developer from a bottle detachably provided to body of the apparatus to the developing unit, and a control unit for actuating supply operation by the supply unit when it is determined by the determination unit that no developer is stored in the developing unit.

Apparatus for initial set-up of developer unit in an image forming

An image duplicating apparatus in which data representative of operational conditions in accordance with which a document sheet is to be duplicated are entered by the user and the natures of document sheets to be duplicated are detected. The data are stored in memory areas of a memory which are respectively assigned to the natures of document sheets. Any one of the memory areas is selected from the memory for the data representative of the operational condition for one of the natures of document sheets written into a selected one of the memory areas and is then read from the storage device for the individual detected natures of document sheets. The copying operation is performed in accordance with the operational conditions represented by the data read by the data read arrangement.

Image duplicating apparatus in which user specified operational

A copying apparatus operating either in a first image scan mode wherein a scan of an original at a standstill on an original table is performed by the movement of an optical system and the image is projected onto a photosensitive member, or in a second image scan mode wherein the optical system standing by a specified position scans an original being transported by an original transport unit and the image is projected onto the photosensitive member. Distance between a position where the optical system actually stops and a standard position where the optical system is supposed to stop is measured, and in an operation in the second image scan mode, the transport of an original and the supply of a copy sheet are adjusted in order to be synchronized with each other, according to the measured distance.

Copying apparatus and copying method

A paper size selecting device for use in a recording apparatus loadable with paper of different sizes selectively, which includes a detector for detecting the size of paper loaded in the apparatus, selecting key for selecting a desired size and a plurality of display members provided for the respective sizes of paper loadable in the apparatus. Each of the display members indicates that the paper of the size concerned is loaded in the apparatus as well as that the paper of the size concerned has been selected by the selecting key.

Paper size selecting device in a recording apparatus

A copying apparatus reduces the possibility of copying error by displaying the copying parameters in different modes. The copying parameters include, for example, the number of copies, the paper size, and the magnification. Since the copying parameters may vary from one copying job to the next, the copying apparatus includes a standard set of copying parameters which are preferably displayed by using continuous lights. After the completion of a copying job, the copying parameters are displayed using intermittent lights, if the copying parameters are different from the set of standard parameters. The intermittent lights provide the next operator of the copying apparatus with an indication that the copying parameters are different from the set of standard parameters.

Copying apparatus having a display warning

An recording apparatus of the present invention has a manual paper feed mechanism which includes a paper inlet, a timing roller and a paper outlet. When a paper is inserted into the paper inlet at a proper timing, the paper is recorded images thereon and then discharged out of the paper outlet. When the paper is inserted at an improper timing, for example, during the rotation of the timing roller, however, the paper is discharged out of the paper outlet without image recording thereon.

Recording apparatus incorporating manual paper feeder

A preset counter apparatus is provided for copying machines having a plurality of key inputs for increasing or decreasing the number of copies to be made. The timer is used to measure a predetermined increment of time for changing the numerical value upon the continuation of a key input. The rate of change of the number of copies to be reproduced can be progressively increased, at least across a predetermined number of increments of values, by the continued activation key member.

Preset counter apparatus for copying machines and the like

The present invention provides a preset counter apparatus for a copying machine wherein input keys are capable of independently controlling the numerical value of the number of copies to be made and displayed. Thus, an operator can activate one key to change the digit positions of units and another key to change the digit position of tens. The control of the number of copies to be made is specifically designed to facilitate operator use and to avoid operator errors. Simultaneous activation of more than one key prevents any change in any values in both the units and tens positions.

A copying apparatus equipped with an improved control device for controlling a copying operation, and including a device for generating a start signal for starting the copying operation, a paper feeding device for starting feeding of copy paper sheets in response to the starting of the copying operation. The control device comprises a device for generating a stop signal for stopping the copying operation and a device for preventing starting of operation of at least the paper feeding device when the stop signal is generated after the start signal has been generated and before the paper feeding device is operated.

Copying apparatus equipped with control device

An automatic paper feeding arrangement for use in a copying machine and the like having a plurality of stages of paper feeding sections for feeding the paper at a selected one of the paper feeding sections. The automatic paper feeding arrangement includes a circuitry for detecting the presence of the paper at each of the paper feeding sections, and a control circuit for cancelling the designation of the paper feeding section previously effected, based on the signal from the detecting circuit when the paper becomes absent in each of the paper feeding sections, and also for designating the paper feeding section in which the paper is initially loaded, based on the signal from the detecting circuit when the paper is loaded in any of the paper feeding sections.

Automatic paper feeding arrangement

This invention is directed to a paper jam detecting device for use in an electrophotographic copying machine which comprises a plurality of paper detector located along the passage of the copy paper transported during copying process, first timer adapted to count the first period of time so as to detect the leading edge of the copy paper by any one of the paper detector and second timer adapted to count the second period of time so as to detect the trailing edge of the copy paper by said one of the paper detector, whereby paper jam can be detected in case where no paper is detected on the first period of time or in case where a paper is detected on the second period of time.

Paper jam detecting device for use in an electrophotographic copying

Sequential control circuit for sequentially controlling the operation of mechanical equipment, for example, an electrophotographic copying apparatus including various devices having respective smaller devices is characterized in that a first train of clock pulses having a fixed predetermined frequency is converted into a third train of clock pulses whose respective pulses are in synchronism with respective pulses of a second train of clock pulses sequentially generated in accordance with respective driven rates of the sequentially driven devices, so that a respective digital timer circuit which is preset with operational time data of its respective device is capable of successively performing the decrement of the predetermined time in response to the respective pulses of the respective third train of clock pulses.

Sequential control circuit means

A trouble detecting system is incorporated in an copying machine having an illumination lamp for projecting light beams onto an original, optical path for transmitting the reflected light beams from the original onto a photoreceptor surface and a scanning device for scanning the original. The trouble detecting system includes a first detector which is disposed along the scanning path of the lamp for detecting the scanning movement of the lamp and a second detector which is coupled with a driving motor for driving the scanning device for detecting the actuation of the driving motor.

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Toyohashi, Japan

Tsuneo Kitagawa