JPH05107102A - Electrical balance - Google Patents

Abstract

PURPOSE:To attain easy-to-identify and accurate indication of overs and short by a pointer-type meter 6. CONSTITUTION:An electrical balance is equipped with a load cell 1, an A/D converter 2, an arithmetic circuit 3, a digital display means 5 of displaying a measured weight and a pointer-type meter 6 indicating overs and shorts. In order to suppress vibration of a pointer, the meter 6 indicating overs and shorts is so designed as to indicate an average value obtained by measuring a difference between the measured weight and a set weight in a plurality of times. Since the pointer-type meter 6 indicates overs and shorts without vibration, indication is easy to identify and accurate and metering can be executed in accordance with the set weight.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric scale used for measuring the weight of an object by adjusting the weight to a preset weight.

[0002]

2. Description of the Related Art For example, when an object is weighed to a certain weight and packed in a bag, it is necessary to weigh the object according to a set weight. At this time, if the scale can display the excess and deficiency with respect to the set weight, it can be conveniently used. Scales to achieve this have already been developed. For example, JP-A-63-8
3616, JP-A-63-83617, JP-A-60-69521, JP-A-63-83620 and JP-A-63-78022 compare the set weight with the measured weight. An electronic balance for displaying values is described. The electronic balances described in these publications digitally display the excess and deficiency with respect to the set weight using a light emitting diode. However, actually, when an object is weighed according to a set weight using this kind of scale, it cannot always be conveniently used. The reason is that the digital display cannot accurately display the degree of excess or deficiency as compared with the analog display.

In order to solve this drawback, a scale for displaying excess and deficiency with an analog meter has been developed (Japanese Patent Laid-Open No. 60-239633). The balance described in this publication digitally displays the measured weight, and displays the excess and deficiency between the measured weight and the set weight with a pointer type analog meter. Since the balance with this structure displays the excess and deficiency with a meter, it can be used conveniently by accurately displaying the weight difference. In addition, since the pointer of the meter moves to indicate the excess or deficiency, it is possible to accurately display the degree of excess or deficiency without displaying the excess or deficiency in stages unlike the digital display that blinks the light emitting diode. it can.

[0004]

However, the scale for indicating the excess or deficiency by the pointer type meter has a drawback that the meter vibrates and it takes time to stand still. The meter can also suppress vibration by the action of a damper.
However, if the damper is made sufficiently open, the movement of the pointer becomes slow and there is a drawback that it takes time to display. In particular, the pointer-type meter that displays the excess or deficiency displays the difference between the measured weight and the set weight in an enlarged manner, and therefore has the drawback that it vibrates so well that it cannot be compared with a meter that displays the total weight.

The present invention was developed for the purpose of solving this drawback, and an important object of the present invention is to suppress the vibration of the pointer so that the measured weight and the set weight can be easily and accurately read. The purpose is to provide an electric scale that can display overs and shorts.

[0006]

In order to achieve the above-mentioned object, an electric balance of the present invention has the following constitution. That is, the electric scale of the present invention includes a load cell 1 for detecting a weight, an A / D converter 2 for converting an output signal of the load cell 1 into a digital quantity, and an A / D converter
Arithmetic circuit 3 for arithmetically processing the measured value digitally converted by D converter 2, and memory circuit 4 for storing the set weight.
And a digital display means 5 for digitally displaying the measured weight.
And a pointer-type meter 6 for calculating and displaying the difference between the measured weight and the set weight by the arithmetic circuit 3. The arithmetic circuit 3 is configured to display the difference between the measured weight and the set weight on the pointer-type meter 6 at regular time intervals.

Further, in order to suppress the vibration of the pointer of the meter 6, the electric scale of the present invention uses the arithmetic circuit 3
However, a plurality of average values of the difference between the measured weight and the set weight are displayed on the meter 6. The arithmetic circuit 3 obtains a plurality of average values of the measured weight and the set weight by a method of averaging the difference between the measured weight and the set weight, and a method of calculating the difference between the average value of the measured weight and the set weight. There is.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. However, the examples shown below are examples of electric scales for embodying the technical idea of the present invention, and the scales of the present invention have the following materials, shapes, structures, and arrangements of components. It is not specific to the structure of. The scale of the present invention can be variously modified within the scope of claims.

Further, in this specification, for easier understanding of the claims, the numbers corresponding to the members shown in the embodiments are referred to as "claims" and "means for solving the problems." It is added to the members shown in "Column". However, the members shown in the claims are not limited to the members of the embodiment.

The electric scale shown in FIGS. 1 and 2 includes a load cell 1 for measuring the weight of an object, an A / D converter 2 for converting an output signal of the load cell 1 into a digital quantity, and an A / D converter. An arithmetic circuit 3 for inputting a signal converted into a digital amount of the D converter 2, a memory circuit 4 for storing a set weight to be measured, a digital display means 5 for digitally displaying the measured weight, and an excess of the measured weight and the set weight. It is provided with a pointer type meter 6 for displaying a shortage.

The load cell 1 converts the weight into an electric signal and outputs an analog signal proportional to the weight.

The A / D converter 2 converts the output signal of the load cell 1 into a digital signal at regular time intervals. The timing when the A / D converter 2 converts the input signal into a digital signal and outputs the digital signal is usually 1 msec to 50 msec.
0 msec, preferably 10 msec to 200 mse
It is set in the range of c. The A / D converter 2 converts the output signal of the load cell 1 into a digital signal and inputs it to the arithmetic circuit 3 at a set time interval.

The arithmetic circuit 3 compares the measured weight corresponding to the digital signal input from the A / D converter 2 with a preset weight, and outputs a value obtained by averaging the comparison values several times to the meter 6. To do. To achieve this,
The arithmetic circuit 3 includes a CPU 7, a memory circuit 4, and a D / A converter 9.

The memory circuit 4 stores the set weight to be weighed. The storage circuit 4 can easily store the set weight by storing the standard weight measured by the scale. In order to realize this, the arithmetic circuit 3 uses C
The set weight set switch 8 is connected to the PU 7. When a standard weight is placed on the balance and the set weight set switch 8 is operated, a set signal is input from the set weight set switch 8 to the CPU 7, and the CPU 7 causes the A / D converter 2
The output signal of is stored in the storage circuit 4. That is, the storage circuit 4 stores a digital amount corresponding to the standard weight. However, the storage circuit 4 can also be connected to a ten-key pad (not shown) to store the set weight.

The CPU 7 compares the digital signal corresponding to the measured weight input from the A / D converter 2 at a constant timing with the set weight of the storage circuit 4 to calculate the excess or deficiency. The calculated excess or deficiency is temporarily stored in the memory. The excess and deficiency stored in the memory are averaged a plurality of times in the order of measurement and input to the meter 6 via the D / A converter 9.

The number that the CPU 7 averages the excess and deficiency is A / D
The optimum value is set in consideration of the timing when the converter 2 measures the weight. If the timing at which the A / D converter 2 outputs the measured weight is long, the average number of excess / deficiency is reduced. If the timing is short, increase the average number of overs and shorts. The reason is that when the timing of the A / D converter 2 is late, if the average number of times is increased, it is delayed in displaying the excess or deficiency on the meter 6. Also, A / D
This is because, when the timing of the converter 2 is short, there is little time delay for the meter 6 to indicate the excess or deficiency even if the average number is increased, and the pointer of the meter 6 can be moved more smoothly.

For example, when the timing at which the A / D converter 2 converts the measured weight into a digital signal and outputs the digital signal is, for example, 100 to 300 msec, the average number of excess and deficiency is set to 2 to 10. That is, 2 to 10 in order
The measured excess and deficiency are averaged and output to the meter 6.

By the way, in this specification, "average value"
Should be interpreted in a broad sense, and not specified as the arithmetic mean of excess or deficiency. Or the geometric mean of multiple excesses and deficiencies multiplied by a coefficient. Further, the average value can be obtained by averaging a plurality of measurement values, subtracting the set weight from the average value, and calculating the deviation.

As shown in FIG. 2, the meter 6 is of a pointer type, and has a scale with the center as 0 point, the deficiency amount on the left side and the excess amount on the right side. Meter 6
Since the pointer can be moved by an analog signal, the digital signal output from the arithmetic circuit 3 is converted into an analog signal by the D / A converter 9 and input to the meter 6.

Furthermore, the scale is equipped with digital display means 5 for displaying the measured weight together with the excess and deficiency. The digital display means 5 receives a signal corresponding to the measured weight from the arithmetic circuit 3 and displays the measured weight as a number.

[0021]

EFFECTS OF THE INVENTION The electric scale of the present invention has a feature that when the weight of an object is weighed according to the set weight, the vibration of the meter pointer indicating the excess or deficiency is very effectively suppressed and the display is easy to see. There is. The reason is that instead of displaying the difference between the measured weight and the set weight immediately, the average value of a plurality of times is displayed.

When an object is adjusted to the set weight and weighed, the amount of the object to be placed on the balance is adjusted by looking at the indication of excess or deficiency.
If the weight put on the scale is less than the set weight, the shortage is guessed and a considerable amount is put on the scale. On the other hand, if the weight put on the scale is heavier than the set weight, a part of the placed object is removed by guessing the excess amount. At this time, the difference between the weight measured by the load cell and the set weight is as shown by the solid line in FIG. In the solid line of this figure, an object is placed on the scale between points C and D. When the output that changes in the state shown in this figure is sent directly to the meter, the pointer of the meter becomes
It vibrates as shown by the chain line. The reason is that the indicated value of the meter changes rapidly between the points C and D.

On the other hand, in the electric scale of the present invention, if the measured values of three times are averaged and displayed, as shown by the alternate long and short dash line, the balance changes without vibrating.
That is, the difference between the measured weight and the set weight is from point C to D
Even if the change suddenly occurs at the point, the amount of change is not directly inputted to the meter, but the signal at the point F is inputted from the point C through the points D ₁ and E ₁ . Also, even if the object placed on the scale is removed and the difference between the measured weight and the set weight changes from point G to point H, the meter will pass from point G to point H _{1 and} point I ₁ The point signal is input. Therefore, even if the difference between the measured weight and the set weight changes abruptly, the electric scale of the present invention does not vibrate the meter pointer and can accurately display the excess and deficiency in an easy-to-see state, which is extremely convenient. It has the feature that you can weigh objects according to the set weight.

[Brief description of drawings]

FIG. 1 is a block diagram of an electric scale showing an embodiment of the present invention.

FIG. 2 is a front view of an electric scale showing an embodiment of the present invention.

FIG. 3 is a graph showing a state in which the excess and deficiency between the measured weight and the set weight changes.

[Explanation of symbols]

1 ... Load cell 2 ... A / D
Converter 3 ... Arithmetic circuit 4 ... Memory circuit 5 ... Digital display means 6 ... Meter 7 ... CPU 8 ... Set weight set switch 9 ... D / A converter

Claims (1)

[Claims] 1. A load cell (1) for detecting a weight, and an A / A for converting an output signal of the load cell (1) into a digital quantity.
D converter (2), arithmetic circuit (3) that arithmetically processes the measured value digitally converted by the A / D converter (2), memory circuit (4) that stores the set weight, and the measured weight is displayed digitally It is equipped with a digital display means (5) and a pointer-type meter (6) that calculates and displays the difference between the measured weight and the set weight by the arithmetic circuit (3), and the arithmetic circuit (3) is constant. In an electric balance configured to display the difference between the measured weight and the set weight on the meter (6) at time intervals, the arithmetic circuit (3) causes the arithmetic circuit (3) to calculate a plurality of average values of the difference between the measured weight and the set weight. An electric scale characterized in that it is configured to display the meter on the meter (6).