Sharp Kabushiki Kaisha Corporation

Other

Sharp Corporation

Katubumi Koyanagi

Hisashi Uede

Yasuhiko Inami

Hiroshi Take

Hiroshi Hamada

Kohzo Yano

Hiroshi Nakauchi

Yutaka Takafuji

Hiroaki Kato

Tadanori Hishida

Hideyoshi Yamaoka

Hiroshi Kuwagaki

Syuhei Yasuda

One of the preferred embodiments of the present invention provides an entirely novel thin-film magnetic-head assembly for a digital-signal recording/reproducing system using multiple tracks. The assembly comprises electronic-circuit components including a combined capacitor/resistor a constant-current source, an amplifier, and an analogue-signal multiplexer, all located inside a casing that surrounds the thin-film magnetic-head. These electronic circuits are present on the upper and lower surfaces of the casing and are connected by means of an elastomer so that these circuits are integrally connected to the thin-film magnetic head. The thin-film magnetic head of the casing may alternatively be bent and extended so that electronic-circuit components can be mounted to it.

Thin-film magnetic head

For an electro-optical display cell which manifests the electrochromic phenomenon to place the cell into the colored state or bleached state in response to current supplied, a constant current driving technique is carried through in the color (write) mode and a constant voltage is carried through in the bleach (erase) mode.

Constant current/constant voltage drive for an electrochromic display

A method for preparing display electrode layers in an electrochromic display device, comprises the steps of forming a transparent, conductive film on a substrate, forming an insulating film over the entire surface of the transparent, conductive film forming a mask at portions on the insulating film other than a display pattern and a lead-in electrode, removing the insulating film at the display pattern and the lead-in electrode, forming an electrochromic material layer over entire portions other than the lead-in electrode, and removing the mask formed on the insulating film. Preferably, an inorganic resist is used to form the mask at the portions on the insulating film.

Manufacture of display electrode layers in electrochromic display devices

An electrochromic display device is characterized by comprising a counter electrode, opposed to a plurality of display segmented electrodes, for absorbing a charge present in some colored display segments. Thereafter, the counter electrode provides a refreshing charge to said some segments from which charge has been taken off. A total amount of charge, defined as the amount of charge necessary for coloring all the display electrodes, is kept constant by refreshing.

Charge transfer type electrochromic display devices

An electrochromic display device comprises a plurality of display segmented electrodes and first additional electrodes, a layer of an electrochromic material in contact with each of the display segmented electrodes and the first additional electrodes, a first connecting circuit for selectively connecting each of the display segmented electrodes into one of two groups, depending on a display pattern to be indicated, a counting circuit for counting the electrodes and determining the difference in display area between the two groups of display segmented electrodes, a circuit responsive to the difference in display area for connecting each of the first additional electrodes into one of the two groups of the display segmented electrodes, a power supply for supplying power to each of the two groups of the first additional electrodes and the display segmented electrodes, and a second additional electrode for keeping the total amount of charge for coloring all the display electrodes constant.

Electrochromic display devices

A driving circuit is provided for coloring and erasing a plurality of segment electrodes contained within an electrochromic display. The driving circuit comprises a first circuit for applying a constant current to at least one of the segment electrodes for coloring purposes, a second circuit for short circuiting the colored ones of the segment electrodes, and a third circuit for applying a constant voltage to at least one of the colored segment electrodes for erasing purposes. A plurality of pulses respectively resulting from the constant current and the constant voltage are applied to the selected segment electrodes on timesharing basis. The second circuit comprises a circuit element belonging to a part of the first circuit or a third circuit.

Electrochromic display driver with faculties of stabilizing coloration

In an electrochromic display comprising a back plate electrode, a plurality of display electrodes, and a reference electrode available for maintaining the potential of the respective display electrodes at a fixed value, there is provided a detector for sensing the counter electromotive force which is developed between the display electrodes and the reference electrode in a manner such that there is created a remarkable difference in the output voltage signal thereof between in the colored state and in the bleached state. Therefore, the output signal from the detector indicates whether the electrochromic display is held in the colored state or the bleached state.

Electric memory detector in an ECD driver

A combined constant potential and constant voltage driving technique is utilized which is much more effective to drive an electrochromic display. The electrochromic display manifests the electrochromic phenomenon to place the display in a colored state or a bleached state in response to current applied thereto. A constant potential driving manner is employed in coloring the electrochromic display, while a constant voltage driving manner is employed in bleaching the same.

Combined constant potential and constant voltage driving technique for

A plurality of segment electrodes are aligned in an electrochromic display device for displaying an analog value in a bargraph fashion. When the analog value to be displayed increases, a coloration drive signal is applied only to the segment electrode which should be changed from the bleached state to the coloration state. Contrarily, when the analog value to be displayed decreases, a bleaching drive signal is applied only to the segment electrode which should be changed from the coloration state to the bleached state. Remaining segment electrodes do not receive any drive signals in transition of the displayed value.

Segmented bargraph display by an electrochromic display device

An additional electrode is provided for developing a secondary electrochromic phenomenon on a counter electrode apart from the major electrochromic phenomenon which is developed between one or more display electrodes and the counter electrode. Current flows from an additional electrode to the counter electrode in developing the secondary electrochromic phenomenon. Coloration of the counter electrode, where the magnitude of an overvoltage of the counter electrode is small is stabilized to thereby enhance electronic properties of the electrochromic display. The material of the additional electrode is selected from metals having an appropriate ionization tendency with respect to an electrolyte, such as Mg, Al, Zn, Cr, Fe, Ni, Sn, and Pb, or a combination thereof. Otherwise, the material of the additional electrode is selected to be an inert material with respect to the electrolyte such as Ag, Au, Pt, Pd, In.sub.2 O.sub.3, and SnO.sub.2 or a combination thereof. The combination which is composed of both the appropriate ionization tendency metals and the inert metals can be available for the additional electrode. The electrochromic display can be controlled under one of several groups of driving techniques consisting of a potentiostatic driving, a constant current driving, and a constant voltage driving method.

Growing community of inventors

Tenri, Japan

Katubumi Koyanagi