Abstract: A manuscript document detecting system and method, wherein a rotatable body having a scanning mirror surface is rotated by a motor, and thereby light emitted from an light-emitting-diode (LED) is guided to a surface of a manuscript document. The rotatable body directs, toward a photo-diode (PD), light reflected from the manuscript document and a light-reflection processing device on a rear surface of an outer frame of a manuscript document mounting stand generates a light receiving signal. The rotatable body further includes an encoder having a row of slits mounted on a circular disk. When the slits pass through a photo sensor, pulse signals are output therefrom. Disturbance light reflected when a pressing plate, which holds the manuscript document against the mounting stand, is lifted generates a light receiving signal of a 75% duty cycle. The reflected light from the manuscript document generates a light receiving signal of a 25% duty cycle.

Abstract: A manuscript document detecting system and method, wherein a rotatable body having a scanning mirror surface is rotated by a motor, and thereby light emitted from an light-emitting-diode (LED) is guided to a surface of a manuscript document. The rotatable body directs, toward a photo-diode (PD), light reflected from the manuscript document and a light-reflection processing device on a rear surface of an outer frame of a manuscript document mounting stand generates a light receiving signal. The rotatable body further includes an encoder having a row of slits mounted on a circular disk. When the slits pass through a photo sensor, pulse signals are output therefrom. Disturbance light reflected when a pressing plate, which holds the manuscript document against the mounting stand, is lifted generates a light receiving signal of a 75% duty cycle. The reflected light from the manuscript document generates a light receiving signal of a 25% duty cycle.

Abstract: An original placement table is provided, on which an original sheet is placed. An original scanning device causes a light beam to scan the original sheet placed on the original placement table. A light receiving device receives a light beam which has been reflected by the original sheet placed on the original placement table after being emitted by the original scanning device. An original edge determining device monitors light intensity of the light beam received by the light receiving device. The original edge determining device determines that the light beam currently being received by the light receiving device is the light beam reflected by an edge of the original sheet placed on the original placement table when a significant variation is detected in the light intensity either for the first time or for the last time in one scanning operation of the original scanning device.

Abstract: A document detecting apparatus installed and used in an image forming apparatus that projects a scanning light is incident to a document placed on a document mount and a size and a position of the document are detected by detecting light reflected from the document, including a document pressing device which presses the document on the document mount, an opening or closing detecting device which detects opening or closing state of the document pressing device, and while the document pressing device is detected as in an opening state, document detecting operation is executed repeatedly and a detecting result is renewed, and, just before it is detected that the pressing board is closed or just before it to detected that an operation for reading an image of the document starts, the size and the position of the document are calculated on the basis of the of the detecting result in a calculation processing device.

Abstract: An original placement table is provided, on which an original sheet is placed. An original scanning device causes a light beam to scan the original sheet placed on the original placement table. A light receiving device receives a light beam which has been reflected by the original sheet placed on the original placement table after being emitted by the original scanning device. An original edge determining device monitors light intensity of the light beam received by the light receiving device. The original edge determining device determines that the light beam currently being received by the light receiving device is the light beam reflected by an edge of the original sheet placed on the original placement table when a significant variation is detected in the light intensity either for the first time or for the last time in one scanning operation of the original scanning device.

Abstract: An original placement table is provided, on which an original sheet is placed. An original scanning device causes a light beam to scan the original sheet placed on the original placement table. A light receiving device receives a light beam which has been reflected by the original sheet placed on the original placement table after being emitted by the original scanning device. An original edge determining device monitors light intensity of the light beam received by the light receiving device. The original edge determining device determines that the light beam currently being received by the light receiving device is the light beam reflected by an edge of the original sheet placed on the original placement table when a significant variation is detected in the light intensity either for the first time or for the last time in one scanning operation of the original scanning device.

Abstract: A network interface unit couples a lattice communication network and at least one token ring network. The network interface unit includes a sequence controller which controls a token detector and a reception register so that message information received from the lattice communication network via a node apparatus connection port is looped back from the token ring network via a terminal connection port and output from the node apparatus connection port when an address detector detects that a destination address matches a stored source address, and absorbed when the address detector detects that the destination address does not match the stored source address.

Abstract: A communication control unit controls data transmission and reception between a terminal and a communication network which includes a full duplex communication path, and a communication is made by transmitting a sending signal which includes a destination address of a destination terminal and transmitting a returning signal when the destination address is confirmed.

Abstract: A communication control unit controls communication between a terminal and a communication network employing a multi-conjunction architecture, and comprises a transmitter/receiver for transmitting and receiving a signal to and from the communication network, a switch part for enabling signal transmission and reception between the terminal and the communication network through the transmitter/receiver in a first state and for disabling the signal transmission and reception between the terminal and the communication network through the transmitter/receiver in a second state, and a control part comprising a signal detecting circuit for detecting whether or not a signal received from the communication network through the transmitter/receiver is intended for the terminal coupled to the communication control unit.

Abstract: A method for a charge control and multi-step deflection control type ink jet printer is disclosed which renders halftone by multi-step gradation. When an ink ejected from a nozzle is to be charged, a charging voltage is suitably varied to cause a shift in deflection by a pitch smaller than one dot pitch in the deflection direction, thereby selectively causing dots in the deflection direction to overlap and separate from each other. The pitch for developing the shift is variable to control the overlapping or separating degree of the dots in order to accomplish gradation in numerous densities.

Abstract: An ink level detector for use with an ink jet printer includes two electrodes for sensing changes in ink level inside an ink reservoir due to consumption. Fresh ink is supplied to the reservoir from an ink cartridge which is mounted in an upper wall of the reservoir. At least one of the two electrodes is positioned adjacent to a location where the cartridge is mounted to the upper wall of the reservoir.

Abstract: A control system for a charge deflection type ink jet printer which prints out one character line of print data by a plurality of strokes on a paper is disclosed. Data associated with odd scanning lines are printed out by one printing stroke of a carriage, then the paper is fed by a predetermined amount, and then data associated with even scanning lines are printed out. Thereafter, the paper is fed by an amount produced by subtracting a number of dots corresponding to a predetermined number of odd or even scanning lines from a number of dots corresponding to the total number of the odd and even scanning lines.

Abstract: A deflection control ink jet recording apparatus is capable of compensating for dislocation of dots at all the deflection steps. A deflection amount is adjusted with respect to two points to determine a correlationship between the amplification gain, charge code and deflection amount, so that an amplification gain and a charge code free from dislocation is set for each deflection step. A charge code compensation value is detected to add it to or subtract it from a predetermined charge code assigned to each deflection step, thereby setting a charge voltage code to be assigned to each deflection step in a printout operation.

Abstract: An ink jet head prints an image by superposing individual dot matrices of at least two colors. A computing unit receives electrical input signals representing the image and generates and feeds corresponding electrical signals representing the individual matrices of the at least two colors to the head means for printing. The computing means includes matrix generator means for generating the matrices in such a manner that the total number of dots to be printed in all of the matrices is limited to a first predetermined value which is less than the maximum possible total number of dots which can be printed in all of said individual dot matrices, and the total number of dots to be printed in the matrices which are formed by superposed dots of different colors is limited to a second predetermined value which is less than said first predetermined value.