Hitachi, Ltd.

Hitachi Denshi Kabushiki Kaisha

Hitachi Engineering Co., Ltd.

Yasuyuki Kozima

Kozo Nakamura

Yasushi Yokosuka

Nagaharu Hamada

Masaharu Tadauchi

Tatsuki Inuzuka

Keisuke Nakashima

Kiyohiko Tanno

Kazuhiko Takaoka

Kunihiro Sakata

Koozoo Nakamura

Kagehiro Yamamoto

Yoshiharu Nagae

Yasuo Inoue

Yuji Mori

Yasuro Hori

Kyohei Fukuda

Teiji Okamoto

Kunio Sato

Minoru Hoshino

Takatoshi Ikeda

Masahiro Takasaka

Takeshi Asai

Yukihito Ishihara

Fumitaka Ito

Saburo Yasukawa

Yoshiaki Tsuchihashi

Toru Takei

Noboru Suemori

Hiroshi Suehiro

Shuichi Hirano

Katuyuki Hunahata

Hayao Kozai

Ichiro Ishi

Kozoo Nakamura

Takamitu Kouno

Youhei Saito

Tadahiko Hasimoto

Atsushi Mizuno

Manabu Shirasaka

A high-speed image signal processing system for encoding an image signal, read out at a high speed, into an encoded signal, and/or for recording a decoded signal obtained through a decoding operation on an encoded signal. The image signal, obtained through a scanning operation on an original document, is sent to an encoder through an image bus. A code bus, provided at an output of the encoder, is connected with an encoded-signal memory for storing the encoded signal. A code transfer unit, for performing input/output operation over the encoded signal and for performing transfer of the encoded signal from the code bus to a system bus, is disposed between the code bus and the system bus. A control unit, performing control over the entire system, and a document management data memory, storing management data for performing management over documents stored in the encoded-signal memory, are connected to the system bus. Further, the control unit, when receiving a request from a data input/output unit, issues a command indicative of the start of the encoding/decoding operation to the encoder/decoder. The encoder/decoder, when receiving the command from the control unit, sequentially processes the data from the data input/output unit without any intervention of the control unit, and when the data processing is completed, informs the control unit of the end of the data processing.

High-speed image signal processing system

In a high-speed image scanner, a driving method is proposed which needs no timing adjustment between the sensor driving pulse and the motor drive pulse required when the motor shifts from an accelerated state to a constant-speed state. The period of the sensor driving pulse is selected to be equal to or 1/N (N=integer) of that of the motor drive pulse at the time of constant-speed operation, and the phases of the sensor driving pulse and motor drive pulse are controlled independently of each other. Thus, even though the sensor driving pulse and the motor drive pulse are out of good timing, each line of the image can be surely read.

Image scanner and image scanning method

A facsimile apparatus which carries out ringing of a telephone first for calling, and transmits a voice message informing of 'absence' and 'facsimile receivable' to a calling station when offhook is not detected during a predetermined period. The facsimile apparatus also transmits a called station identification signal CED after a silence interval of about 5 seconds. When the calling station onhooks a handset during the period of ringing of the telephone by judging that the called station is absent, a fee for a telephone call will not be charged. Furthermore, by setting the silence interval, the CED signal after the voice message is prevented from being heard by the calling station.

Facsimile receiving method and facsimile apparatus carrying out the

Three chrominance signals representative of a color image are represented by a coordinate system in a uniform color space, and a probability of occurrence of colors on the color space and a correlation of the chrominance signals for pixels are referenced in encoding color image information signals.

Method and apparatus of encoding color image information

An apparatus for decoding a coded image into a pixel image and printing the pixel image at an essentially constant speed without using decoding means which decodes the coded image faster than a printing speed and pixel memory means for storing at least one page of pixel information. Decoding amount calculation means for calculating the decoding amount of the code to be decoded is provided, and compare means monitors whether the decoding amount exceeds the printing amount of the pixels to be printed and the code is converted to other code depending on the comparison result. The decoding means needs only receive the converted code from the code memory means and decode it to the pixel information. Thus, the constant speed printing apparatus is attained without high speed decoding means and one-page memory.

Method and appratus for decoding and printing coded image, and facsimile

A modem (modulator-demodulator) apparatus provided with modem circuits having different signal processing standards, which is optimized for a facsimile machine. Switching of modem functions can be accurately performed by concurrently operating modems with required standards selected from modems with different standards incorporated in a modem apparatus and incorporating in a common input/output port means for selectively switching an input/output of each modem and a dedicated signal detection means required for the switching, and further by constituting a facsimile using the this modem apparatus so as to perform the switching control from the facsimile body or automatically. Moreover, the modem signal after switching can be obtained by using a low speed modem as dedicated signal detection means, detecting a flag pattern after having completed an initial sequence consisting of detection of the presence (power) of an input signal, automatic gain control (AGC), carrier reproduction (PLL), timing synchronization, etc. and deciding that a signal for receiving a low speed modem signal has been received on the condition that at least one of the flag pattern has been detected.

Multimode modem for facsimile

In a synchronizing circuit, such as a DPLL (Digital Phase-Locked Loop), adapted to be synchronized in accordance with clock signals of an external clock, a programmable timer in the circuit is forcedly reset in synchronism with the edge of an external clock signal pulse at the time of the clock signal's initial state in accordance with a clock detection circuit. Subsequently, baud timing of the external clock signals is detected by making use of internal clock signals produced by the circuit. Synchronism is thus established and maintained between the circuit and the external device.

Synchronizing system

An image processing system which can learn user's preference to satisfy him to the full, and also comprises means for inquiring a user about his satisfication degree to enhance it. The image processing system comprises means for learning user's preference such as his manner of setting and pressing a button, a destination, a condition set for copying, and means for changing a control parameter on the basis of the learning result.

Image processing system suitable for use for a facsimile

A first phase control loop not including a signal delay part and a second phase control loop including a signal delay part such as an automatic equalizer are formed independently of each other in a demodulator incorporated in a MODEM. The first and second phase control loops are arranged in such a relation that an input to the second phase control loop is not affected by an output of the first phase control loop, so that correction of a frequency offset by the first phase control loop and correction of a frequency jitter by the second phase control loop can be carried out independently of each other. This arrangement facilitates the design of the first and second phase control loops and improves the stability of the phase control system.

Phase control device

The disclosure relates to a projector having an arrangement of polarizers and liquid crystal cells aligned on the axis of light in the order a first color polarizer colored in red, a first twisted nematic liquid crystal cell, a second twisted nematic liquid crystal cell, a second color polarizer colored in a green, a third twisted nematic liquid, a neutral polarizer and Guest-Host type colored in blue. Since, according to this, a polarizer having inferior color characteristics can be replaced by a Guest-Host type liquid crystal cell, the excitation purity and the scope of color reproduction are improved. Further, since the mixture of color is additive, the brightness of the reproduced color is also much improved.

Projector using guest-host liquid crystal cells for improved color purity

When a document and a recording medium are moved in a vertical scanning direction to read the document and record signals on the recording medium, the read signals are stored in a line buffer memory. The present invention changes over hysteretically a high speed vertical scan mode and a low speed vertical scan mode in accordance with the number of the buffered code bits in the line buffer memory to read the document and record the signal on the recording medium. Thus, the present invention reduces the number of stops of vertical scan.

Control method of vertical scan speed

The present invention provides a method for controlling the movement of a print medium to be printed, for example, in a facsimile device. The invention uses printing velocities for each line (or printing unit) to be printed, which are calculated based on the number of black picture elements in the image signal related to this line (or picture unit). These calculated printing velocities are stored each for succeeding line to be printed and are then used to determine the moving velocity of the print medium for the actual line being printed.

A method of controlling the movement of a medium to be printed

A picture signal processing apparatus comprises a signal processing means for performing signal processing such as picture element density conversion of picture signals, a first memory means for storing temporarily picture signals as object of the signal processing, a first signal path through which signals are received or transmitted between the signal processing means and the first memory means, an encoding means for performing encoding processing, a second memory means for storing temporarily picture signals as object of the encoding processing, a second signal path through which signals are received or transmitted between the encoding means and the second memory means, a control means for controlling the signal processing means and the encoding means, and a third signal path through which signals are received or transmitted between the signal processing means and the encoding means, thereby signal processing and encoding processing can be performed concurrently and high speed processing is realized.

Picture signal processing apparatus

A control circuit is used for matrix drive recording. It includes a microprocessor, a RAM for storing data to be recorded therein, an address signal editing circuit for modifying the input addresses to the RAM, a shift register for converting the data from parallel to serial form and transferring it to a recording circuit, and a DMA controller for reading the data from the RAM and transferring it to the shift register.

Control circuit for matrix-driven recording

In a facsimile transmitter in which original document information to be transmitted is photoelectrically converted to an analog video signal which is binary-coded through a binary-coder to be stored in a buffer memory, and the stored information is read from the buffer memory to be sent to transmission lines the transmitter is further provided with a transition detector for detecting the transition point of the binary-coded video signal read from the buffer memory, a run length signal generator for counting the number of pulses of a clock signal until the transition point of the binary-coded video signal is detected thereby to generate a run length signal, and a small computer for effecting the redundancy suppressing process on the basis of the binary-coded video signal and the run length signal.

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Hitachi, Japan

Yasuyuki Kozima