Tokyo Electric Co.

Kabushiki Kaisha Tec

Yoshihisa Nishiyama

Tohru Kitagawa

Seiji Suzuki

Kunihiko Fujii

Yukihiro Hirosaki

Koichiro Sato

Noriyasu Fujii

Yasuhiro Ushijima

Sadao Ohyoshi

Shuji Takabayashi

A load cell unit in accordance with the present invention comprises a load cell and a wiring board. The load cell comprises a flexible member provided with a through hole formed between the fixed end and the moving end thereof so as to form four flexible portions, and strain gages attached to the flexible portions, respectively. The wiring board is provided with a circuit connected to the strain gages of the load cell so as to form a bridge circuit including the strain gages, and a processing circuit connected to the bridge circuit. The wiring board has a first major surface mounted with at least film capacitors among the circuit elements of the processing circuit, and a second major surface. A first shield cover is attached to the first major surface of the wiring board so as to cover the circuit elements mounted on the first major surface, and a second shield cover is attached to the second major surface of the wiring board so as to cover the circuit elements mounted on the second major surface of the wiring board. The wiring board is disposed beside the load cell with the first shield cover disposed in the through hole of the load cell. The wiring board of the load cell unit is shielded effectively and the load cell unit has a compact construction.

Load cell unit

A load cell weighing device has a plurality of load cells. In the device, detection values are respectively output from the load cells. The detection values are digitized by analog-to-digital conversion circuits. Low frequency noise components involved in the digitized detection values are reduced by digital filters. Then, the noise-reduced values are summed to provide weight data.

Device for measuring a physical force

A resistor-adjusting apparatus is provided for adjusting resistors of a load-cell scale which has a load cell, having a resistance bridge circuit, for generating an electrical signal corresponding to a load weight, and an A/D converting section for converting the electrical signal supplied from the load cell into a digital signal corresponding to the load weight. A thin-film resistor for adjusting temperature characteristic, which is connected to the bridge circuit, is provided on the load cell so as to be exposed. The resistor-adjusting apparatus comprises a resistor adjustor for removing part of the thin-film resistor in response to a control signal and thus adjusting a resistance thereof, and a control unit for supplying, to the resistor adjustor, a control signal corresponding to digital signals that are generated by the A/D converting section in response to a predetermined load weight at different temperatures, causing the resistor adjustor to change the resistance of the thin film resistor.

Method and apparatus for adjusting resistors in load-cell scale

The invention provides an electronic appliance wherein a detection output of a sensor means is not influenced by a high frequency component originating in external radio waves. The electronic appliance comprises a conductor member located in a spaced relationship by a predetermined distance from a base which constitutes a body case together with a housing. A by-pass route is provided for by-passing a sensor means near the conductor member to introduce a high frequency component of electric current flow induced in the conductor member to the base. A distributed capacitance forming means is interposed in the by-pass route. Thus, a high frequency component of electric current flow induced in the conductor member is released to the body case via the by-pass route.

Electronic appliance

A multi-range load cell weighing scale includes a load receiving pan provided at the top of a casing, a high-range load cell disposed in the casing for a high range of weight determination, and a low-range load cell disposed in the casing for a low range of weight determination in a substantially horizontally juxtaposed relation to the high-range load cell. The low-range load cell has one end connected to one end of the high-range load cell. The other end of the high-range load cell is supported on the bottom of the casing, while the other end of the low-range load cell defines a load support on which the pan is supported. The load to be weighed bears on the two load cells simultaneously. The scale enables a wide range of highly accurate weight determination, despite its use of inexpensive load cells.

Multi-range load cell weighing scale

A load cell has a span resistor hole for enclosing a span resistor that is provided on the beam body, so that the span resistor may be free from the influence of environmental factors such as temperature and moisture and thus can be satisfactorily protected. The span resistor hole is located in a deformation-proof portion of the beam body, whereby the span resistor is not exposed to external mechanical force.

Load cell

An analog/digital converter has an integrator for integrating for a predetermined time a difference voltage (&lt;VX) between a voltage equal to half a source voltage V1 and an input voltage VX supplied to the first input terminal after an initialization period, generating an output voltage increasing in proportion to the input voltage, and generating an output voltage decreasing at a predetermined rate after the predetermined time has elapsed, and a counter for generating count data until the output voltage from the integrator reaches a predetermined level. This converter also has a resistor-type voltage divider and a capacitor. The voltage divider is coupled between source terminals and generating from first and second output terminals first and second output voltages E1 and E2 which are lower than voltage V1/2. The capacitor has one terminal coupled to the first input terminal of the integrator and the other terminal coupled to the first and second output terminals of the resistor-type voltage divider through first and second switches. During initialization, the first switch closes and a voltage (E1-V1/2) is charged on the capacitor. After the predetermined period of time has elasped, the second switch is closed and a voltage (E1+E2-V1/2) is applied to the first input terminal of the integrator.

Analog/digital converter

A load cell wherein strain gauges are produced by a thin film process on a pattern forming surface of a strain-inducible element in such a manner that the resistances of the strain gauges are varied in accordance with deformations caused in thin portions of the strain-inducible element, and adjustable resistors are deposited by the thin film process for an electric circuit assembly including a differential amplifier, a potential divider, a signal amplifier and a zero-point setter. And each of the resistors is adjusted by trimming simultaneously with trimming adjustment of the strain gauges.

Load cell having a thin film strain-inducible element

A load cell type weight measuring device includes a load cell which produces an output voltage corresponding to the weight applied thereto, an amplifier circuit for amplifying the output voltage of the load cell, and an A/D converter for converting an output voltage of the amplifier circuit to digital data. This weight measuring device further includes a rated voltage generating circuit for generating an output voltage equal to the output voltage generated from the load cell which is applied with a rated weight; switches for selectively connecting the load cell, the rated voltage generating circuit and the ground terminal to the amplifier circuit; and a microcomputer which gives control signals to the switches and inhibits the output data of the A/D converter from being supplied as effective weight measurement data when it is detected that the difference between two items of output digital data of the A/D converter, which are respectively obtained when the ground terminal and the rated voltage generating circuit are selected, exceeds a predetermined range.

Load cell type weight measuring device and a sensitivity checking method

A load cell type weight-measuring device includes a load cell; a test voltage generator for generating a voltage equal to a rated output voltage of the load cell; a zero-point setting circuit; an amplifying circuit; a switching circuit for selectively coupling the load cell and test voltage generator to the amplifying circuit; and a data processing circuit for generating weight data corresponding to an output signal from the amplifying circuit. The amplifying circuit includes a first amplifier of a gain 1 for amplifying an output voltage from the zero-point setting circuit; first and second resistors; and a second amplifier whose first input terminal is connected to an output terminal of the first amplifier through the first resistor and is connected to its own output terminal through the second resistor and whose second input terminal is connected to the switching circuit.

Load cell type weight-measuring device

In an automatic weighing apparatus wherein a weight measurement is performed by passing a commodity on a weighing conveyor which is coupled so as to become a load of a load cell, and a label on which data based on the measured value are printed is automatically stuck to the commodity, while a print fixing label in which a print content is fixed can also be issued; the zero-point setting is automatically performed at times when the commodity does not exist on the weighing conveyor, so as to execute in a stable state a measurement having an accurate reference point.

Zero-point adjusting method for automatic weighing apparatus

A full-auto labeling system having sending-in conveyor, a weighing conveyor and a sticking conveyor disposed in alignment, and the respective conveyors provided with sensors for detecting a commodity, so as to control an operation of a load cell with outputs of the sensors providing the basis of an improvement which consists of a load cell periodically operated even when no commodity is being transported, whereby when a measurement value becomes necessary a stable operation can be immediately performed, and that A/D conversion by the load cell is executed twice with a single start signal, a second output being taken as the measurement value, whereby the measurement value of high reliability can be obtained.

Full-auto labeling system

An electronic weight measuring device includes a load cell producing an output voltage varying from -V.sub.X to 0 volts according to the weight of load, a bias circuit producing a variable bias voltage V.sub.X, voltage generator receiving the output voltages from the load cell and bias circuit and producing an output voltage varying within a range from -1/2 V.sub.X to +1/2 V.sub.X, and an analog-digital converter for converting the output voltage from the voltage generator. The electronic weight measuring device further includes a zero point setting circuit coupled to the load cell and bias circuit and applying an output voltage varying with the output voltage from the bias circuit to the load cell, so that the no-load output voltage of the load cell is kept at substantially 0 volts.

Electronic weight measuring device

An electronic weight measuring device comprises a load cell to produce a voltage signal corresponding to the weight of load applied, an amplifier circuit for amplifying the output signal of the load cell, an A/D converter circuit for converting the output signal of the amplifier circuit into a digital signal, a counter for counting the number of clock pulses corresponding to the output signal of the A/D converter circuit, a microcomputer for deriving a weight indicating signal from the count output signal of the counter, and a display unit for displaying the weight indicating signal from the microcomputer. The electronic weight measuring device further includes a bias circuit to apply a bias voltage to the amplifier circuit so as to reduce to a zero level the output signal produced from the amplifier circuit when it has received from the load cell an output signal corresponding to 1/2 of the rated weight, and the A/D converter circuit produces a digital output signal corresponding to the absolute value of a positive or negative output signal from the amplifier circuit.

Growing community of inventors

Shizuoka, Japan

Yoshihisa Nishiyama