Abstract:
An analog display includes a dial and a movable EL pointer positioned adjacent the dial for indicating a measured value. The pointer is an elongated EL lamp having a conductive pin extending through one end of the lamp and about which the lamp pivots. The pin is mechanically secured to the lamp and is electrically connected to the front electrode of the lamp. A hole larger than cross-sectional diameter of the pin is formed in the rear electrode and in the phosphor layer to prevent the pin from shorting the front electrode to the rear electrode. A conductive spring rests on the pin to provide electrical power to the front electrode. Power is supplied to the rear electrode either through a conductive ferrule attached to the rear electrode or through a resilient wiper. The wiper can be attached to the pointer or to the face of the dial. For plural pointers, concentric conductive pins are used with a sliding contact for the rear electrodes.
Abstract:
A scale is disclosed for a measuring instrument in which a plurality of display elements, specifically liquid crystal display elements which are energizable to a visible condition or an enhanced visible condition selectively to provide a linear scale or a logarithmic scale. The scale is divided into decades which specifically have twelve display elements of which ten are selectively energizable to provide the linear scale and then to provide the logarithmic scale.
Abstract:
A device for displaying the value of a quantity represented by input data comprises a mobile indicator member (24) driven by a stepping motor (20), a control circuit (18) for this motor for delivering drive pulses to the motor in response to the input data to move the indicator member to a position corresponding to the value of the quantity, and a dial (26) for showing an indexing system, for example a scale, which cooperates with the indicator member to indicate the value at least approximately. The dial comprises a liquid crystal, electrochromic or electroluminescent electrooptical display device (26) which displays the indexing system in response to signals from another control circuit (28) when the latter receives an activation signal. The device enables values of a single quantity situated in different ranges or values of distinct quantities to be indicated, by making the cell selectively display corresponding indexing systems. A specific application of the device is for automobile dashboards.
Abstract:
A measuring symbol driving circuit drives the measurement symbols on a liquid crystal display in a digital multimeter. This measuring symbol driving circuit includes a rotary measuring range changeover switch which selects the respective measuring symbols to be displayed. A control signal generating circuit receives the backplane pulse signal supplied to the common electrode of the liquid crystal display, and phase inverts this signal through the use of an exclusive OR gate in order to develop a control signal supplied to the measuring symbol selected by the measuring range changeover switch. Further, the driving circuit includes a circuit for monitoring the presence of a short circuit between the input jack and common electrode of the digital multimeter to selectively display a short circuit indicator symbol. This input comparing circuit receives the backplane pulse signal at one terminal of an exclusive OR gate and supplies the other terminal of an exclusive OR gate the output of a comparator which is logically high when a short circuit is detected in order to reverse the phase of the backplane signal to produce a control signal for application to the display symbol, and supply the logical low signal to the input of the exclusive OR gate to apply a signal equivalent to the backplane pulse signal to the control terminal of the short circuit symbol to maintain this symbol in a non-displayed state.
Abstract:
An electric gage driving a pointer has an extended spindle so that the gage movement can be substantially spaced from the pointer. The gage includes a spindle, an armature driving the spindle, a bobbin supporting a bearing for the spindle and electrical coils around the bobbin. An outrigger support remote from the bobbin and adjacent the pointer holds another spindle bearing which may be misaligned with the bobbin. The bearing on the bobbin accommodates the misaligned spindle.
Abstract:
An electrical indicator device for providing simultaneous relatively coarse analog, and higher-resolution, digital readings of a particular electrical parameter, all in one instrument. The device includes either a d'Arsonval meter movement or a servo-motor or other motivated electro-responsive device which carries a pointer movable over a predetermined portion of a calibrated meter scale plate, and a liquid crystal display having multiple digits, each digit being constituted of multiple segments. The segments are disposed completely within the confines of the meter scale plate, but lie substantially completely outside of the said predetermined portion thereof. The display is driven or energized by a digital voltmeter having its terminals connected to receive and monitor the same parameter that is being measured by the motivated electro-responsive device. The arrangement is such that the individual segments of the digital display are always completely visible regardless of the position which the pointer occupies with respect to the said predetermined portion of the scale plate.
Abstract:
A signal strength meter indicates signal level directly in dBmV. The signal under test is attenuated to a level which centers a meter indicator, and the attenuator movement is translated into numerical direct reading information of signal level. Push button switches select a channel for testing, and each switch incorporates gain compensation for the frequency of the signal to be tested. Within each channel the operator can select between audio and video carrier frequency.