Abstract: A signal communication system includes a control portion and an operation portion. The control portion has an output data transmitter for transmitting output data to the operation portion in the form of a serial signal, and an input data receiver for receiving input data signal from the operation portion. The operation portion has an input data transmitter for transmitting the input data to the control portion in the form of a serial signal, and an output data receiver for receiving the output data from the control signal, and an operable device for executing an operation in accordance with the output data. The control portion further has an output data memory for storing output data, a timing signal generator for generating a timing signal, and a timing signal transmitter for transmitting the timing signal to the output data transmitter and the operable device.

Abstract: The present invention is directed to the provision of a sheet feeder unit mounted in a copying machine or the like having a sheet transport mechanism. The sheet feeder unit feeds sheets to the sheet transport mechanism, and the sheets fed into the sheet transport mechanism are transported by the sheet transport mechanism. Each sheet being transported by the sheet transport mechanism is detected by a pair of sensors disposed with a prescribed space provided between each other, and the sheet transporting speed is calculated from the time in which the sheet travels the distance between the two sensors. The sheet feeding condition is set on the basis of the sheet transporting speed of the sheet feeder unit so that the sheets fed from the sheet feeder unit do not overlap each other.

Abstract: A data generator generates input data for a pulse generator from source data corresponding to a desired pulse width in order to make the pulse generator generate an output pulse having the desired pulse width. In the data generator, the source data are converted into the input data for the pulse generator based on a predetermined conversion relation; the predetermined conversion relation is varied; the width of an output pulse of the pulse generator is compared with that of a calibration pulse having a predetermined pulse width; and a conversion relation between calibration source data corresponding to a pulse width of the calibration pulse and the input data is maintained when the width of the output coincides with that of the calibration pulse.

Abstract: A semiconductor integrated circuit constructed on a single chip. Either one of a signal inputted to a clock signal input terminal and a signal obtained by dividing the frequency of the clock signal inputted to the clock signal input terminal is selected by a selecting circuit responsive to a selection signal supplied from the exterior of the chip to be supplied to a control circuit. Consequently, the frequency dividing circuit can be bypassed in response to the selecting circuit. Accordingly, it is possible to easily provide operation at a high frequency exceeding the maximum operating frequency of component devices forming the semiconductor integrated circuit. This can be done by connecting an external circuit having the same function as that of the circuit bypassed and capable of higher-speed operation.

Abstract: A copier permitting recording and editing of an original document. A copy image, corresponding to an original document read by an original reading part, can be formed directly by an image forming part, or a representation of the original document can be recorded on a removable recording medium mounted in the copying machine. The recorded representation can be edited, if desired. The editing control signals can also be recorded on the recording medium. The representations recorded on the recording medium can be read with or without editing, permitting a copy image to be formed by the image forming part.

Abstract: A recording apparatus has a printer mechanism for printing images successively on sheets of copying paper, and an image control circuit for delivering image information controllably to the printer mechanism so as to enable the latter to print the images successively. The image control circuit includes a plurality of page memories each for storing image information per single page, a first changeover switch for writing image information selectively into the page memories, and a second changeover switch for reading image information selectively from the page memories. When a sheet of copying paper is jammed in the printer mechanism, a microcomputer system controls the second changeover switch to select a switching mode to read an item of image information out of one of the page memories which stores the item of information to be printed on the jammed sheet of copying paper, for thereby allowing the image to be printed in a shorter period of time after paper jam clearance.