Seikosha Co., Ltd.

Kabushiki Kaisha Seikosha

Tetsuro Konno

Hitoshi Ikeno

Mitsuyuki Sugita

Hirofumi Yanagi

Tetsuya Fujita

Yutaka Kanai

Nakanobu Moritani

Isamu Hoshino

Hirobumi Yanagi

The electrophotographic recording apparatus includes a photo-sensitive member comprises of a transparent support plate, a transparent electrode formed on the support, a transparent electrode layer formed on the photoconductive layer, and floating electrodes formed on the photoconductive layer. The floating electrodes are composed of small plural electrode segments independently and electrically insulatively separated from each other. These electrode segments may be separated from each other by insulating partition walls. The photosensitive member is suitable for use in an electrophotographic recording system of directly transferring charged toner onto a recording paper.

Electrophotographic recording system

An overtone crystal oscillator includes a crystal vibrator, a CMOS circuit connected in parallel to the crystal vibrator, and two load capacitors connected to the input and output of the CMOS circuit, respectively. The capacitors have respective capacitances C.sub.g and C.sub.d determined to satisfy at least one of following two conditions wherein the first condition is that an oscillation starting resistance R.sub.KN of a desired N-th overtone is sufficiently larger than an effective resistance R.sub.QN of the crystal vibrator of the N-th overtone, the oscillation starting resistance being expressed as:

Overtone crystal oscillator

Disclosed is an electrophotographic recording apparatus comprising a pair of toner containers for accommodating a toner, a photosensitive member constituted by a transparent substratum, a transparent electrode and a photoconductive layer, a light irradiating means for irradiating this photosensitive member with light such as a laser beam from the transparent substratum side (rear surface side) thereof, and a transfering means. With this apparatus, an area required for the photosensitive device can be made small, a long durable life of the photosensitive member can be ensured, and no special toner is required.

Electrophotographic recording apparatus

An adjustable frequency crystal oscillator circuit has an adjustment capacitor which is connected in parallel, via a switching circuit, to a load capacitor of a piezoelectric vibrator. The oscillation frequency is controlled by varying the duty factor of the pulses applied to the switching circuit for switching the adjustment capacitor into and out of parallel connection with the load capacitor. The frequency-temperature characteristic is compensated for by varying the duty factor according to changes in temperature. No trimmer capacitor is needed, and the frequency-temperature characteristic is effectively compensated for over a wide temperature range.

Adjustable frequency crystal oscillator with temperature compensation

An oscillator comprises plural electrodes formed on a piezoelectric vibrator, and the oscillation frequency is controlled by varying the duty factor of the pulses for switching an effective electrode area of the plural electrodes. The frequency-temperature characteristic of the oscillator is compensated by varying the duty factor of the switching pulses according to temperature variations. No trimmer condenser is needed, and the frequency-temperature characteristic is compensated over a wide temperature range.

Circuitry for switching effective electrode area on a crystal in a

A driving electrode on a surface of the piezoelectric vibrator in accordance with the present invention has a blank which is narrow at the center portion and wide at the right and left portions on the Z axis. And the driving electrode is the shape easy to operate in the fundamental main vibration, and hard to operate in the spurious vibration. Thus the piezoelectric vibrator operates efficiently in the fundamental main vibration.

Electrode configuration for thickness-shear mode piezoelectric vibrator

A thickness-shear mode piezo-electric vibrator comprises a piezo-electric crystal operable in the thickness-shear mode, driving electrodes formed on opposed surfaces of the crystal, and an addition mass formed on at least one of the driving electrodes and positioned on the nodal line of a 3-fold harmonic vibration so that the frequency f.sub.o of the fundamental main vibration and the frequency f.sub.3s of the 3-fold harmonic vibration always satisfy the following relation within the practical application ranges of temperature and load capacitance; ##EQU1## thereby effectively eliminating or preventing the 'abnormal frequency phenomenon' which would otherwise occur due to the 3-fold harmonic vibrations.

Thickness-shear piezo-electric vibrator with additional mass for mode

A thickness-shear mode quartz oscillator characterized in that an addition mass fitted to a driving electrode of the oscillator for the purpose of adjusting its oscillation frequency has a non-circular shape or the fitting position thereof is deviated from the center of a quartz slice, or both in combination. Such addition mass provides different piezoelectric effects and effects of addition of the mass between the fundamental main vibration and harmonic vibrations and eliminates or restricts a 'frequency abnormal phenomenon'. Consequently, even when driven by a C-MOS type integrated circuit not having a frequency selection circuit in its oscillation loop, the thickness-shear mode quartz oscillator exhibits stable frequency-temperature characteristics.

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Tokyo, Japan

Tetsuro Konno