Other

Endress U. Hauser Gmbh U. Co.

Endress+hauser Gmbh+co.

Ernst Luder

Traugott Kallfass

Hubert Benzel

Frank Hegner

Joerg Schaepperle

Georg Schneider

Kai Schleupen

Stefan Kull

Gerhard Bader

Christian Borgwardt

Volker Hochholzer

Masoud Habibi

In a first variant of this pressure sensor with a substrate and a diaphragm which are joined together parallel to each other in a defined spaced relationship, forming a chamber sealed at least at the edge, the chamber-side surface of the diaphragm is completely covered with a diaphragm electrode. The chamber-side surface of the substrate supports a reference electrode consisting of an outer portion, which extends along the edge of the chamber and whose capacitance is virtually pressure-independent, and a pressure-dependent central portion, which is located at the center of the substrate and is connected with the outer portion via a connecting portion. The remainder of the substrate surface is covered with a measuring electrode spaced from the reference electrode by a constant distance. In a second circular variant and in a third, rectangular variant, the reference electrode consists of an outer portion, which extends along the edge of the chamber and whose capacitance is virtually pressure-independent, and two pressure-dependent central portions, which are each located in one half of the substrate symmetrically with respect to the substrate center and are connected with the outer portion via one connecting portion each, and whose boundary curves are continuous and are optimized by an iterative method. In a third variant, the reference electrode differs from that of the second variant in that it is not centrosymmetrical, but symmetrical with respect to a substrate diameter.

Capacitive pressure sensors with high linearity by optimizing electrode

The apparatus for providing an autostereoscopic view of three dimensional structures includes a display device including several different two-dimensional views of a three-dimensional structure, optical image forming devices arranged in front of the display device and a screen for forming images in an observation plane from light rays issuing from the optical image forming devices so that images of the two-dimensional views appear in respective observation zones in the observation plane. The optical image forming devices (AE) are provided with aperture stops and include a device for overlapping the observation zones (BZ6) to form overlapping zones (UZ6). The aperture stops are provided with edge regions having a continuous transitional decrease of light transmission from complete transmission at their edges to zero transmission at a predetermined distance from their edges.

Apparatus and process for autostereoscopic viewing of a

The process of converting a digital data word having N-bits into an analog voltage value includes decrementing or incrementing a counter word (B) having N-bits from a respective maximum or minimum value to form a series of decremented or incremented values, synchronizing the decrementing or incrementing of the counter word (B) to a time course of an analog reference voltage (U.sub.ramp) having a ramp-shaped time dependence, evaluating a logical connection function of the decremented or incremented values of the counter word (B) with a digital data word (A) to determine when one of the decremented or incremented values of the counter word (B) is equal to a complement of the digital data word (A) and setting an output analog voltage value (U.sub.column) equal to the analog reference voltage (U.sub.ramp) as soon as the decremented or incremented value of counter word (B) equal to the complement of data word (A) is reached.

Process and apparatus for conversion of an N-bit digital data word into

The circuit device has a plurality of cascaded stages. Each cascaded stage includes several partial stages and has at most two capacitors (C.sub.n1, C.sub.nB) and at most seven transistors (T.sub.n1, T.sub.n2, T.sub.n3, T.sub.n4, T.sub.n5, T.sub.n6, T.sub.n7). The circuit device includes a device for controlling the cascaded stages with four periodic clock signals (.PHI..sub.1, .PHI..sub.2, .PHI..sub.3, .sub.101 .sub.4) phase-shifted about 90.degree. relative to each other such that each of the cascaded stages is controlled by a respective assigned one of four predetermined sets of two of the four periodic clock signals and the same one of the four predetermined set repeats every fifth cascaded stage. Each cascaded stage includes an output stage (12, 12') including a bootstrap-capacitor (C.sub.nB) and three transistors (T.sub.n5, T.sub.n6, T.sub.n7) electrically connected to the bootstrap-capacitor (C.sub.nB); and a charging and discharging stage (11) for the bootstrap-capacitor (C.sub.nB). The charging and discharging stage (11) includes at least one transistor (T.sub.n4) connected electrically to the bootstrap capacitor (C.sub.nB). Each cascaded stage can advantageously also include an inverter stage connected to the charging and discharging stage and including two transistors (T.sub.n1, T.sub.n2) and a memory capacitor (C.sub.n1) electrically connected with each other and controlled by an input signal so that so that both transistors (T.sub.n1, T.sub.n2) are never simultaneously conducting.

Circuit device for controlling circuit components connected in series or

Resistive and capacitive absolute pressure sensors are disclosed which are made by surface micromachining and thin-film techniques. In the case of a capacitive sensor, the electrodes have a high insulation resistance relative to each other, the diaphragm exhibits only little tensile strain in the finished condition, no sublimation step is necessary to prevent the diaphragm from sticking to the substrate, the diaphragm provides a measurement signal over a wide pressure range even if its rests against the substrate, the measurement signal is virtually temperature-independent, and only few chemical-vapor-deposition and photolithographic steps are necessary. The capacitive sensor has a glass substrate and a diaphragm which bound a hermetically sealed cavity, the substrate supporting, on the cavity side, a substrate electrode with first interconnection tracks or corner pads extending therefrom, the diaphragm being made of the material of a first insulating layer, which firmly adheres, at least in part, to the substrate at the edge of the cavity, and supporting, on the side remote from the cavity, a top electrode and a second insulating layer which completely covers the top electrode and the diaphragm and hermetically seals the cavity, and the top electrode having second interconnection tracks extending therefrom onto the first insulating layer outside the diaphragm. In the case of a resistive sensor, the substrate electrode is omitted, and the top electrode is replaced by a half or full bridge consisting of piezoresistors. Four manufacturing process variants are disclosed.

Methods of manufacturing thin-film absolute pressure sensors

A switching electrode especially for controlling image points in liquid crystal indicators has a ground electrode, a dielectric, and a counterlectrode. Parameters of the switching element are controllable in a broad region independently from one another. The production of the switching element can be easily integrated in production process of a liquid crystal indicator.

Method of producing electronic switching element

A moisture sensor is manufactured by applying a thin layer of tantalum oxide to a moisture insensitive substrate and placing at least two electrodes on the tantalum oxide layer. The tantalum oxide layer comprises the oxide of a highly resistive low density tantalum where the tantalum in the layer applied to the substrate has a density of less than 15 g/cm.sup.3. The low density tantalum may be applied by cathode sputtering and the oxide may be formed by anodic oxidation.

Method of manufacturing a moisture sensor

A moisture sensor comprises a moisture-sensitive layer formed from the oxide of highly resistive porous low density tantalum on a moisture-insensitive substrate. Between the substrate and the moisture-sensitive tantalum oxide layer there is a base electrode of an anodically oxidizable metal, preferably tantalum, of a density higher than the density of the low density tantalum from which the tantalum oxide layer is formed. A covering electrode partially covering the tantalum oxide layer has windows through which the water vapor containing medium can penetrate into the moisture-sensitive tantalum oxide layer. The inactive regions of the tantalum oxide layer disposed below the windows are removed to increase the rate of response.

Moisture sensor with valve metal composition electrodes

A moisture sensor including a thin layer of tantalum oxide applied to a moisture insensitive substrate and at least two electrodes placed on the tantalum oxide layer spaced apart from each other wherein the tantalum oxide layer comprises the oxide of a highly resistive low density tantalum where the tantalum in the layer applied to the substrate has a density of less than 15 g/cm.sup.3.

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Stuttgart, Germany

Ernst Luder