215 results about "Capacitance ratio" patented technology

PCT No. PCT/JP97/03807 Sec. 371 Date Dec. 21, 1998 Sec. 102(e) Date Dec. 21, 1998 PCT Filed Oct. 22, 1997 PCT Pub. No. WO98/38736 PCT Pub. Date Sep. 3, 1998In a piezoelectric vibrator which has excitation electrodes respectively disposed on the top surface and undersurface of a piezoelectric substrate, at least one of the excitation electrodes being an inverted-mesa electrode that has a recess formed in the opposite side of the electrode from the side which contacts the piezoelectric substrate. Thus, an AT-cut quartz resonator in which the capacitance ratio gamma is reduced to a value below the limit value can be provided as a result of use of the inverted-mesa electrodes as excitation electrodes.

In the hold phase, two negative feedback circuits constituted by the negative feedback capacitors 6p and 6m and two positive feedback circuits constituted by positive feedback capacitors are provided between an input terminal and an output terminal of an operational amplifier. Here, in a sampling phase before a hold phase, charges according an input signal V1p is stored in each of the capacitors, and charges according to an input signal V1p are stored in each of the capacitors. As a result, a gain of the switched capacitor amplifier circuit is derived from (Ca+C)/(Ca−Cx) wherein Ca indicates an electrostatic capacitance of the negative feedback capacitors, and Cx indicates an electrostatic capacitance of the positive feedback capacitors, and thus the gain can be increased without significantly increasing an electrostatic capacitance ratio.

The present invention provides a display apparatus that can reduce a voltage irregularity and a brightness irregularity accompanied by making an enlarged and a high resolution type display apparatus. The display apparatus comprises plural pixel electrodes 5 arranged in a matrix, a switching element 3 connected with the pixel electrode, a scanning electrode 1, a picture signal electrode 2, an opposite electrode forming a capacitance with the pixel electrode 5, and further comprising; a storage capacitance 7 between the pixel electrode 5 and the scanning electrode 5 other than the scanning electrode 1 of the present line; more than two capacitance elements connected with the pixel electrode 5, including at least one of a gate-drain inter-electrode capacitance 4 of the switching element 3 and the storage capacitance 7, having a different value according to the distance from the power feeding edge of the scanning electrode 1; wherein, each capacitance in each pixel is set so that, when all capacitance connected with the pixel electrode 5 in a pixel is denoted as Ctot, a first capacitance ratio α gd=Cgd/Ctot increases continuously or in stages according to the distance from the power feeding edge of the scanning electrode 1, or a second capacitance ratio α st=Cst/Ctot is substantially constant.

A tunable oscillator includes an input for receiving an input signal from a source of precision frequency such as a CMOS quartz crystal oscillator. The tunable oscillator converts the frequency of the input signal to a first current using a frequency to current converter. The current produced is proportional to a first capacitor, C1. The first current is replicated to produce a subsequent current using a current mirror structure. The subsequent current is then used to generate a periodic signal using a current to frequency converter. The output frequency of the current to frequency converter is inversely proportional to a second capacitor, C2. As such the output frequency of the tunable oscillator is tunable by changing the value of the capacitance ratio C1/C2. The invention is suitable for applications that require a precision tunable source of frequency such as automated test equipment (ATE) and electrical instrumentation.

The invention relates to a capacitance ratio type icing thickness sensor and a detection method thereof. The sensor is characterized in that: a relative capacitance value detection loop is formed by a single chip microcomputer inside a sensor, a double-channel capacitance digital converter, detected media icing or air spreading between pole plates, a group of parallel pole plate detection capacitors which have an geometric structure the same with a reference parallel plate pole plate detection capacitor and are arranged according to fixed ruler scale spacing positions, as well as a double-channel programmable control scale gating circuit; under the control of the single chip microcomputer, the capacitance value obtained by each relative capacitance value detection loop is compared with the reference capacitance value obtained by a reference capacitance value detection loop which is formed by the single chip microcomputer inside the sensor, the double-channel capacitance digital converter and the reference parallel plate pole plate detection capacitor, and the measurement on the surface icing thickness of the sensor is realized by analyzing and judging a ratio result. Under the condition of ice rain or freezing, the sensor can continuously and automatically detect the icing thickness of suspended power transmission lines, pylons, buildings, equipment surfaces, branches, etc.

Disclosed herein is a functional electrical stimulation (FES) device and system. In one embodiment, sequential bipolar pulse stimulation may be provided to an area of a living body via one or more electrode leads applied to the area via a FES device comprising a current pulse generating circuit comprising output nodes for operative coupling to the one or more electrode leads, and configured for operative coupling to a voltage supply. The current pulse generating circuit generally comprises positive and negative stimulation paths drawing from the voltage supply to respectively apply positive and negative currents through the area via the one or more electrode leads. In one example, the stimulation paths comprise respective capacitive elements, a capacitance ratio of which dictating, at least in part, an amplitude ratio of the positive and negative currents, wherein periodic alternative activation of the stimulation paths provides the sequential bipolar pulse stimulation. In another example, each path comprises a respective charging element and a respective activation switch, wherein each respective charging element is charged by the voltage supply and discharged upon activation of the respective activation switch to generate positive and negative current pulses respectively, such that a pulse rise time of the positive and negative current pulses is predominantly dictated by a switching speed of each respective switch. Systems and uses for these devices, and FES in general, are also described.

An LCD device includes a plurality of pixels arranged in a matrix. Each pixel includes a first sub-pixel and a second sub-pixel. Each of the first and second sub-pixels includes a liquid crystal capacitor and a storage capacitor. A capacitance ratio of the liquid crystal capacitor to the storage capacitor in the first sub-pixel is smaller than that in the second sub-pixel. In a first pixel and a second pixel among all the pixels, the first sub-pixel of the first pixel and the first sub-pixel of the second pixel are staggered, and the second sub-pixel of the first pixel and the second sub-pixel of the second pixel are staggered.

A quartz crystal resonator has a quartz crystal tuning fork base and quartz crystal tuning fork tines connected to the quartz crystal tuning fork base. Each of the quartz crystal tuning fork tines has opposite main surfaces, a groove formed in at least one of the main surfaces, and an electrode disposed in the groove formed in at least one of the main surfaces so that a merit value M₁ of a fundamental mode of vibration of the quartz crystal tuning fork resonator is greater than a merit value M₂ of a second overtone mode of vibration thereof. The merit values M₁ and M₂ are defined by the ratios Q₁/r₁ and Q₂/r₂, respectively, where Q₁ and Q₂ represent a quality factor of the fundamental mode of vibration and the second overtone mode of vibration, respectively, of the quartz crystal tuning fork resonator and r₁ and r₂ represent a capacitance ratio of the fundamental mode of vibration and the second overtone mode of vibration, respectively, of the quartz crystal tuning fork resonator. A piezoelectric constant e₁₂ of the the quartz crystal tuning fork resonator is within a range of 0.095 C/m² to 0.19 C/m² in the absolute value.

A liquid crystal display device includes a plurality of pixels arranged in a matrix mode. Each pixel contains at least a first sub-pixel and a second sub-pixel, each of the first or the second sub-pixel includes a liquid crystal capacitor and a storage capacitor, and the liquid crystal capacitance and the storage capacitance ratio of the first sub-pixel is less than that of the second sub-pixel, wherein, in a first pixel and a second pixel of all the pixels, the first sub-pixel of the first pixel is in dislocation setting with the first sub-pixel of the second pixel, and the second sub-pixels pixel of the first pixel is in dislocation setting with the second sub-pixel of the second pixel.

A processor of a signal processing circuit for calibrating an electro-capacitance pressure sensor includes a coefficient arithmetic section for calculating calibration value and a calibration arithmetic section. The calibration arithmetic section calculates an electro-capacitance ratio between electro-capacitance C1 and C2 detected by an electro-capacitance pressure sensor and conducts a calibration calculation from the electro-capacitance ratio to output a converted pressure value. The processor includes a fundamental arithmetic section for conducting a calculation given by f=(Z-W)/(X-Y) for predetermined arguments X, Y, Z and W input by the coefficient arithmetic section or the calibration arithmetic section and for outputting the calculation result f to the one of the coefficient arithmetic section and the calibration arithmetic section providing the input. The fundamental arithmetic section provides shared calculating for the coefficient calculation and calibration calculation.

The invention discloses an LCD faceplate, a driving method and an LCD. The LCD faceplate comprises a plurality of pixel units arranged in arrays. Each pixel unit is provided with a plurality of sub-pixel zones and comprises a plurality of driving elements, a plurality of liquid crystal capacitances and a plurality of storing capacitances. The driving elements are respectively arranged in one of the sub-pixel zones and are respectively electrically connected with a scanning line and a data line. The liquid crystal capacitances are respectively arranged in the sub-pixel zones and each liquid crystal capacitance is electrically connected with the corresponding driving element. The storing capacitances are respectively arranged in the sub-pixel zones and each storing capacitance is electrically connected with the corresponding driving element; wherein, the capacitance ratio between the storing capacitance and the liquid crystal capacitance of any one sub-pixel zone of the same pixel zone is not equal to the capacitance ratios between the storing capacitance and the liquid crystal capacitance of other sub-pixel zones. The invention can lead the light penetration rates of each sub-pixel zones to be different so as to improve the phenomenon of color cast of the LCD faceplate.

The invention discloses a current sampling circuit and relates to the technical field of switching power supply by using a resonant zero current technology. The current sampling circuit comprises a sampling branch circuit, a sampling resistor and a potential translational circuit, wherein the sampling branch circuit is connected in parallel with an oscillating capacitor of a switching power supply circuit and the potential translational circuit is connected in parallel with the sampling resistor; the sampling branch circuit comprises a shut capacitor and a current transformer which are connected in series; the sampling resistor and the current transformer are connected in parallel; the potential translational circuit comprises a level isolating capacitor and a clamping diode, the cathode of the clamping diode and the level isolating capacitor are connected in series, and the anode of the clamping diode is grounded. Because the current sampling circuit is connected in parallel with a resonant capacitor, a current distribution relation is determined by a capacitance ratio of shunt capacitance to main circuit capacitance, and only very low current is available in the current sampling circuit, thereby the power loss of the current sampling circuit is greatly reduced. Furthermore, in the circuit, current detection of a heavy current circuit can be realized by using a small mutual inductor, thereby reducing the cost and the volume.

The embodiment of the invention provides a liquid crystal display panel and an adjustment method of the liquid crystal display panel, and relates to the technical field of display. The changes of the capacitance ratios in pixel units can be monitored in real time, the reference voltage value of a public electrode can be adjusted in real time according to the conditions of environment changes, and therefore the image flicking phenomenon on the liquid crystal display panel can be kept at the lowest degree. The liquid crystal display panel comprises an array substrate, wherein the array substrate comprises a plurality of pixel units which are arranged in a matrix mode, each pixel unit comprises a first transistor, a second transistor, a first data line, a second data line, a first data line connection line, a first gate line, a second gate line, a second gate line connection line and a pixel electrode. The liquid crystal display panel further comprises the public electrode. The liquid crystal display panel which can keep the image flicking display at the lowest degree can be manufactured.

The present invention provides a configuration method of main reactive compensation capacitor group of transformer substation. The configuration method is characterized by the following steps: first, arranging the capacitance ratio of capacitors according to the optimum capacitance ratio of the capacitors; secondly, the reactive compensation capacitance required by the main transformer of the transformer substation is directly multiplied by the corresponding coefficient in Table 2, to acquire the capacitance of the group of capacitors. The formula of optimum indexes in Formula I is adopted to optimize the configuration of the main reactive compensation capacitor group of transformer substation. The configuration method solves the technical problem that the improper configuration of the main reactive compensation capacitor group of transformer substation can not effectively complete the reaction compensation, leads to the equipment waste, and has no function of maintaining the voltage and reducing the net loss.

The invention discloses a mutual capacitance type touch key signal detection method. The method comprises the steps that initialization is carried out, wherein the electric charge quantity of an A point in the initialization phase is obtained; measurement is carried out, the voltage of the A point is obtained according to conservation of the electric charge of the A point; whether reference capacitance is larger than parasitic mutual capacitance or not is judged according to the judgment result of whether the voltage VA2 of a capacitive coupling point A is larger than the initial voltage of the capacitive coupling point A or not; whether a touch signal exists or not is judged according to the judgment result. Compared with the prior art, detection of the touch signal is completed within one period through a reference capacitance comparison method, the detection speed is much higher than that of a traditional relaxation oscillation method; Because of the single-period detection, a capacitor of a touch key does not need to be charged and discharged frequently, system power consumption is greatly saved; in addition, due to the method, a system has very low dynamic power consumption, working frequency can be flexibly changed, the touch key can be used under the low-power-consumption standby mode with the rigorous requirement for power consumption, and the hardware guarantee is provided for a full-touch human-computer interaction interface. The invention further discloses a detection circuit of the touch key signal detection method.

This invention is an amplification circuit which limits increased power consumption and circuit surface area use and an imaging device including this amplification circuit. After initially discharging a capacitor, a signal charge corresponding to the difference between pixel signals is transferred repeatedly to the capacitor during an integration phase storing a signal charge proportional to the number of repetitions. The output of amplification is the signal charge accumulated in the capacitor. The gain is independent of the capacitor capacitance ratio. Thus the capacitor size can be smaller than conventional amplification circuits.