Minolta Camera Kabushiki Kaisha

Minolta Company, Ltd.

Minolta Camera Co., Ltd.

Ken Matsubara

Tomohiko Masuda

Hirohisa Kitano

Itaru Saito

Tsukasa Yagi

Kouichi Shingaki

Kenichi Wada

Yuji Kamoda

Koji Wakamiya

Kohichi Shingaki

Isao Doi

Atsushi Fujita

Itaru Saitoh

Shuji Iino

Yuji Enoguchi

Masazumi Morishita

Hirchisa Kitano

Hiroshisa Kitano

Tatsuya Kanazawa

Yasuyuki Hiromoto

While light of R, G and B is switched from one to another and directed to a plurality of light shutter elements made of PLZT, a voltage is applied in accordance with image data between individual electrodes for the respective light shutter elements and a common electrode for all the light shutter elements. While a half-wave voltage Vr for light of R is applied to the individual electrodes, the voltage applied to the common electrode is altered to 0V, Vr-Vg and Vr-Vb in synchronization with switch of the three primary colors so that half-wave voltages for the respective colors can be applied to the light shutter elements.

Light shutter device and a driving method thereof

A light shutter device including a group of light shutter elements and formed on a light shutter chip made of PLZT has a construction in which an electrode gap is set wider in a element in which an electric field acts more strongly to equalize half wavelength voltages of elements almost to the same level since electric fields acting on the elements are different in strength from each other even under a prescribed voltage applied between a common electrode and each of individual electrodes . An electrode gap of an element having a weaker electric field is comparatively set narrower, whereas an electrode gap of an element having a stronger electric field is set comparatively wider. Moreover, a shape of electrodes of each element are altered so as to make half wavelength voltages of elements almost equal.

Light shutter device

A light shutter device which has a plurality of light transmitting portions (light shutter elements) on a planar PLZT substrate. By applying voltages between a common electrode and individual electrodes to apply electric fields to the light shutter elements, the light shutter elements transmit and shut light individually. Suppose each of the individual electrodes faces the common electrode at a distance L and has a dimension W in a direction perpendicular to the direction of electric field, W/L>2. Suppose each of the individual electrodes has a dimension D in the direction of electric field, preferably D/L>0.5. Further, the individual electrodes are so placed that the distance between a side of one light shutter element which extends in a direction perpendicular to the direction of electric field and each of the individual electrodes which drive the other light shutter elements is not less than 5L.

An image forming apparatus which is capable of composing an image with a high accuracy on an image receiving member with use of a plurality of light signal emitting heads. The image forming apparatus, which is used for forming an image on the image receiving member such as a photographic paper or a electrophotographic photosensitive member. Each light signal emitting head turns on and off a plurality of light signal emitting elements extending in a main scanning direction in accordance with image data. The image receiving member is guided by a cylindrical guide roller with being adhered to the curving section of the guide roller at an exposure position. The light emergent from each light signal emitting head is changed its optical path at a dichroic prism or a half mirror and exposes the image receiving member linearly.

Image forming apparatus provided with a plurality of light signal emitting heads

A method for measuring the quantity of light emitted from an optical write head which drives an array of light shutter elements extending in a main scanning direction individually in accordance with image data. In order to measure the quantity of light outputted from each of the light shutter elements, a photosensor is moved in the main scanning direction at a constant speed while the light shutter elements are driven in such a way that adjacent elements are not driven at a time. While light shutter elements which are in odd numbers in the array are driven, the photosensor is moved forward to measure the quantities of light outputted therefrom, and while light shutter elements which are in even numbers in the array are driven, the photosensor is moved backward to measure the quantities of light outputted therefrom. The optical write head is employed in a printer together with a light-quantity measuring unit for the optical write head, so that light-quantity measurement and production of light-quantity correction data are possible at real time.

Method for measuring the quantity of light emergent from an optical tip array and image forming apparatus provided with an optical tip array

A PLZT optical shutter array includes an optical shutter array, a driving circuit, a temperature compensating circuit, an IC control unit, a driving IC and a temperature sensor. Temperature of the optical shutter array is detected by the temperature sensor, and based on a voltage representing the temperature and a reference voltage for driving optical shutter element, a driving voltage for the optical shutter element is generated in the temperature compensating circuit. The driving voltage is applied to the optical shutter element through the IC control unit and a driving IC. As a result, a voltage applying apparatus for a light signal emitter which has a simple structure and allows cost reduction is provided.

Voltage applying apparatus facilitating adjustment of a driving voltage

Disclosed is an optical writing device having an array of a plurality of writing light shutter elements for an image forming purpose. The optical writing device also has at least one first monitoring light shutter element and at least one second monitoring light shutter element. During recording period, the first second monitoring light shutter element is frequently driven, and the second monitoring light shutter element is infrequently driven. After the recording period, the first and second monitoring light shutter elements are driven with varying voltage, and light amounts from the first and second monitoring light shutter elements are sensed by a sensor. Based on the output from the sensor, optimal drive voltage for the next recording period is set.

Optical writing device with controlled driving voltages

In a display device in which one dimensional light emitted from a light emitting element driven by an image signal generating device is scanned by moving a reflecting member so as to provide a two-dimensional image to an observer utilizing after image phenomenon, in order to prevent variation in an amplitude or variation of the center of vibration of the reflecting member which may cause image deviation, angle of displacement of the reflection member is detected by a detector, a position signal from the detector is compared with a reference signal and based on the result of comparison, the image signal generating device is controlled.

Image display device using vibrating mirror

An optical shutter element drive mechanism for driving optical shutter elements that are electrically equivalent to condensers by charging and discharging the elements by a power source and switching elements. The optical shutter element drive mechanism includes a resistor through which a current for charging the optical shutter elements flows when the optical shutter elements are charged and through which a current for discharging the optical shutter elements flows when the optical shutter elements are discharged.

Optical shutter element drive mechanism

The present invention relates to a light shutter array which has shutter elements made of an electro-optical material. The quantity of light transmitted by each shutter element in the array is measured, and a limit is set relative to the smallest measured value such that the transmitted light quantity distribution of the light shutter array would be regarded substantially even if all shutter elements transmitted light within the limit. To achieve such a substantially even distribution, shutter elements which transmit light over the limit are subjected to trimming. Since trimmed regions on a shutter element do not transmit light, the quantity of light transmitted through a trimmed shutter element is lowered in proportion to the area of the trimmed region. Alternatively, individual electrodes and/or portions of a common electrode corresponding to the shutter elements which transmit light over the limit are trimmed. As a result, electric fields generated in the shutter elements are weakened, and the polarizing effects of the shutter elements are weakened. Consequently, the quantity of light transmitted through those shutter elements is lowered.

Light shutter array with a substantially even distribution transmitted

An optical shutter device for use, e.g., in an optical printer includes a plurality of electrooptic chips each having a plurality of very small segments for optical modulation. The optical shutter device has a voltage adjusting circuit which individually supplies the driving voltage to the chips depending on the light transmitting characteristics intrinsic to the chips. Thus, even when the chips have different light transmitting characteristics, the image produced by the chips will have a uniform intensity.

Optical shutter device

An image forming apparatus which comprises a light shutter disposed between a source of light and an image carrier, which is electrostatically charged to a predetermined polarity, and capable of exhibiting a light transmissivity which varies according to a voltage applied to the light shutter. A first voltage of a predetermined direction is applied to the light shutter according to image information during a first period in which a first area of the image carrier passes across the light shutter, to form the electrostatic latent image on the image carrier. This electrostatic latent image is subsequently developed into a toner image. In order to substantially recover the light shutter from a light-induced fatigue, i.e., internal polarization of an electro-optical material forming the light shutter, a second voltage of a direction counter to the predetermined direction is applied to the light shutter during a second period in which a second area of the image carrier passes across the light shutter.

Image forming apparatus

An image forming apparatus for producing completed copies includes a main body. An image forming device is provided in the main body for forming images on paper to produce the completed copies. A tray is also provided in the main body for receiving and stacking the completed copies produced by the image forming device. A sheet transport path transports the completed copies from the image forming device to the tray. In addition, a support mechanism movably supports the tray from a first position inside of said main body where the completed copies are received and stacked thereon to a second position outside of the main body where the completed copies can be manually removed therefrom.

Image forming apparatus having a movable sheet receiving tray

A method and device for driving an electro-optical light shutter array including a plurality of shutter elements each having an electro-optical effect to polarize an incident light by setting up an electric field. The device includes a plurality of individual electrodes provided on the respective shutter elements and a common electrode provided on the respective shutter elements electrically in common. A square pulse is applied to the arbitrary individual electrode while a triangular pulse is applied to the common electrode to set up an electric field of which an intensity continuously varies within one driving period. Moreover, an alternating electric field may be set up in the electro-optical light shutter array in a recovery period. In this case, a first light amount when the positive electric field is set up and a second light amount when the negative electric field is set up are detected. A recovery operation is carried out until the first and second light amounts become substantially equal with each other.

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Takatsuki, Japan

Ken Matsubara