JP3153125B2 - Measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring apparatus having a function of displaying a detected value, which shows a certain value when a measured value is not measured, but changes to a predetermined value or more during a measurement, and particularly to power saving. The present invention relates to a measurement device that has been developed.

[0002]

2. Description of the Related Art Various measuring devices for measuring various physical quantities are widely used. Such a measuring device has a display function of displaying the detected amount. FIG. 6 shows a conventional measurement using an electric micrometer as an example, in which a probe comes in contact with the surface of an object to be measured, and the displacement of the other end of the probe is detected by a differential transformer to detect the external dimensions. FIG. 2 is a diagram illustrating a configuration of an apparatus.

[0006] In FIG. 6, reference numeral 1 denotes a measuring unit, here an electric micrometer. Reference numeral 2 denotes a display unit for displaying the detection value of the measurement unit 1, which is shown here as a bar graph display device. As shown, the bar graph display device arranges light emitting elements such as LEDs in a line and displays LEDs up to a position corresponding to the detected value, and displays the detected value like an analog signal. The display is controlled by digital processing.

[0004] Some displays display digitally the detected values as they are, and a display unit is provided with, for example, display elements such as 7-segment LEDs such as the number of display digits. In addition, a fluorescent display tube or the like is used. In the measuring device having the display unit as described above, the power consumption of the display unit 2 accounts for a large proportion of the power consumption of the entire measuring device. LED used for bar graphs and 7-segment display elements
Is larger in power consumption than the power consumption of the measuring unit 1 and the like.

[0005] The measuring device as described above is used when the user turns on the power switch of the measuring device when performing the measurement, or when the measuring device is always used in a production line or the like, and is automatically supplied. There is a case where a physical quantity of an object to be measured is measured and its detected value is displayed. A measuring device used in such a production line and used for performing an operation based on a detection value displayed by an operator will be referred to as a manual measuring device here. In the manual measuring device, the display unit is always in operation, and the display unit consumes a lot of power.

[0006]

In the case where the user turns on the power switch every time the display is used, the display unit is activated when it is necessary to perform display, and power is consumed by the display unit. Although it is unavoidable, in the case of a manual measuring device, the time to actually detect and display the physical quantity of the device under test is short, and the effective detection is effective during most of the operating time. Often no value is displayed. For example, when the object to be measured is a workpiece, and the dimension of the completed workpiece is measured with a measuring device such as an electric micrometer to check whether the workpiece is within a predetermined allowable range, the time required for processing is long. , The electric micrometer is always in operation even during machining, which does not need to measure the dimensions and display the detected values.
It wastes power.

Some measuring devices are driven by a battery, and such wasteful power consumption is caused by a measuring device driven by a battery, a digital display having a large number of digits, or an array of a large number of elements. L for a bar graph display device for detailed display
This is particularly problematic when using a light emitting element such as an ED which consumes a large amount of power. An object of the present invention is to reduce the power consumption of a measuring device that has a display unit that displays a detected value and that displays a period during which it is not necessary to display the detected value, thereby wasting power. .

[0008]

FIG. 1 is a block diagram showing a basic configuration of a measuring apparatus according to the present invention. As shown in FIG. 1, the measuring device of the present invention includes a measuring unit 1 that detects a physical quantity of an object to be measured and outputs a detected amount, and a display unit 2 that displays the detected amount output by the measuring unit 1. The detection amount output by the measurement unit 1 indicates a predetermined value when not measuring, and in a measuring device that changes from a predetermined value to a predetermined direction at the time of measurement. The threshold value is stored in the threshold value register 3 that stores a threshold value that is set so as to always change beyond the threshold value, and the detection amount output from the measurement unit 1 is compared with the threshold value stored in the threshold value register 3. When the value is between the predetermined values, the display unit 2 is deactivated,
When the detected amount exceeds the threshold value in a predetermined direction, a comparison means 4 is provided for controlling the display unit 2 to be in an operating state so that the detected amount is displayed.

In the measuring apparatus, when the physical quantity of the object to be measured is not detected, the detected amount indicates a certain value in the non-measurement state. Generally, it changes to some extent from a predetermined value. For example, in an electric micrometer, when the contact is not in contact with the object to be measured and the dimension of the object to be measured is not measured, the contact is stopped at a predetermined position by the limiter. The value indicates a predetermined value. Also, in the case of an electric measuring device for measuring a voltage or the like, when the device under test does not output a voltage or is in a non-measurement state where it does not contact the output terminal,
The detected value indicates zero.

The measurement apparatus of the present invention pays attention to such a change in the detection amount between the measurement state and the non-measurement state, and determines that the detection state is the non-measurement state when the detection amount is equal to or less than the threshold value, and the measurement state when the detection amount is equal to or more than the threshold value. In the non-measurement state, the display unit is turned off to reduce wasteful power consumption. When the measuring unit 4 is set to the non-measurement state, nothing is displayed on the display unit. Therefore, nothing is displayed because the power to the measuring device is not turned on. Since the amount is equal to or less than the threshold value, it is not possible to determine whether the display unit is in the non-measurement state and only the display unit is off. Therefore, it is desirable to provide a pilot lamp with low power consumption and to turn on the pilot lamp so that it can be distinguished when the detection amount is equal to or less than the threshold value and the measurement is not performed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. In these descriptions, a measuring device for detecting an inner diameter and displaying it on a bar graph will be described as an example. However, the present invention is not limited to this. It can be applied to other measurement devices. FIG. 2 is a diagram illustrating an appearance of the measuring device according to the embodiment of the present invention.

In FIG. 2, reference numeral 11 denotes a measuring unit of a measuring device called a column gauge for detecting the inner diameter of a hole formed in a processing step, and 12 denotes a gauge, and the same is applied to the other side. There is. Reference numeral 21 denotes a display unit having a bar graph display LED 22 and a pilot lamp 23.
When the tube portion of the measuring section 11 is inserted into the hole to be measured, the probe 12 is displaced according to the diameter of the hole, and the diameter of the hole can be detected by detecting the displacement. The value of the diameter of the detected hole is
A bar graph is displayed on the display unit 21.

FIG. 3 is a block diagram showing a configuration of a processing circuit of the measuring apparatus according to the embodiment of the present invention. In FIG. 3, reference numeral 100 denotes an object to be measured, 12 and 12 ′ are the probes shown in FIG. 2, and 53 and 54 generate electric signals corresponding to displacements of the probes 12 and 12 ′. 55 and 56 are first and second differential transformers 53
The first and second rectifier circuits rectify the output signals of the first and second rectifier circuits 55 and 56, and 57 is an adder circuit for generating a signal indicating the diameter by adding the outputs of the first and second rectifier circuits 55 and 56. An auto-zero circuit for correcting the output signal of the adder circuit 57 so that the value when the reference master is measured becomes zero, and an A / D converter 59 for converting the output of the auto-zero circuit 58 into a digital signal. . Processing such as display of detected values is performed by a microcomputer. The microcomputer includes a CPU 61, a ROM 62, a RAM 63,
I / O port 64 and switch interface 65
And a display interface 67. Various operation switches 66 for operating the measuring device are connected to the switch interface 65. The bar graph display 21 is connected to the display interface 67, and the bar graph L
Data to be displayed on the ED 22 and a drive signal for the pilot lamp 23 are supplied. The microcomputer is A / D
The detected value converted into the digital signal by the converter 59 is read, and a display corresponding to the detected value is performed on the bar graph display 21. The display interface 67 includes a power supply 71.
Is connected to a switch 72 for controlling on / off of the power supply to the bar graph display 21, and is controlled by a signal from a display interface 67. Although not shown,
The power supply 71 supplies power to the microcomputer and other circuits.

FIG. 4 is a diagram for explaining the principle of determining a measurement state and a non-measurement state from a detection signal in this embodiment. In the non-measurement state in which the tube portion of the measuring section 11 is not inserted into the hole, the probe 12 is in the most protruding state, but does not protrude beyond a predetermined position. Therefore, the detection value in the non-measurement state is constant. When the cylindrical portion of the measuring section 11 is inserted into the hole to measure the inner diameter of the hole, the probe 12
Is displaced by contacting the inner wall of the hole. The inner diameter of the hole is the sum of the displacements of the two tracing styluses 12, and changes in a direction smaller than a predetermined value in the non-measurement state as shown in FIG. And
When the measurement is completed and the cylindrical portion of the measuring section 11 is pulled out of the hole, the detected value returns to the predetermined value in the non-measurement state. Therefore, the threshold level is set so that it is smaller than a predetermined value in the non-measurement state and the detection amount at the time of measurement is always smaller than this value. When the detected value is equal to or higher than the threshold level, the switch 72 is turned off to set the bar graph display 2
The power supply to the bar graph display 21 is turned off by turning on the switch 72 when the detected value falls below this threshold level. While the switch 72 is off, the pilot lamp 23 is turned on. When the switch 72 is switched from the off state to the on state, power supply is started and the bar graph display 21 is turned on. Although there is some time delay before the bar graph display 21 is brought into the operating state, the LED has good responsiveness,
Such a time delay is not a problem.

FIG. 5 is a flowchart showing processing in the microcomputer of the measuring device according to the embodiment of the present invention. In step 200, the switch 72 is turned off, the bar graph display 21 is turned off, and the pilot lamp 23 is turned on. In step 201,
The digitally converted detection value output from the A / D converter 59 via the I / O port 64 is read. Step 20
2 is set in advance and stored in the ROM 62 or the RAM 6
The detected value is compared with the threshold value stored in No. 3, and if the detected value is larger than the threshold value, it is in the non-measurement state. Therefore, the process returns to step 201. If the detected value is smaller than the threshold value, it is in the measurement state. In step 203, the switch 72 is turned on, and the bar graph display 21 is turned on. In step 204, the detected value is read again, and in step 205, the threshold value and the detected value are compared. If the detected value is smaller than the threshold value, it is in the measurement state, and a process of displaying the detected value is performed in step 206. If the detected value is larger than the threshold value, it means that the measurement has not been performed.
In step 7, the switch 72 is turned off, the bar graph display 21 is turned off, and the process returns to step 201.

Although the embodiment in which the present invention is applied to a measuring device for measuring the inner diameter of a hole has been described above, the same applies to the case where the outer diameter of a cylinder is measured. The same applies to the case where an air micrometer or the like is used, and the present invention is also applicable to other electric measurement devices and the like.

[0017]

As described above, according to the present invention,
Since unnecessary display is not performed, useless power consumption can be reduced. Thereby, the battery replacement cycle in the battery-driven measuring device can be lengthened.

[Brief description of the drawings]

FIG. 1 is a diagram showing a basic configuration of a measuring device of the present invention.

FIG. 2 is an external view of a measuring device according to an embodiment.

FIG. 3 is a circuit block diagram of the measuring device of the embodiment.

FIG. 4 is a diagram showing a principle of determining a measurement state and a non-measurement state in the embodiment.

FIG. 5 is a flowchart illustrating a display process in the embodiment.

FIG. 6 is a view showing a conventional measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Measurement part 2 ... Display part 3 ... Threshold register 4 ... Comparison means 11 ... Measurement part of a measuring device 12,12 '... Sensor 21 ... Bar graph display 22 ... Bar graph display LED 23 ... Pilot lamp

Claims (2)

(57) [Claims] 1. A measuring section (1) for detecting a physical quantity of an object to be measured (100) and outputting a detected quantity, and a display section (2) for displaying the detected quantity output by the measuring section (1). The detection amount output by the measurement unit (1) indicates a predetermined value when not measuring, and changes in a predetermined direction from the predetermined value during measurement. In the measurement device, the detection amount changes in the predetermined direction from the predetermined value. A threshold register (3) for storing a threshold set such that a detection amount at the time of measurement always exceeds the threshold, and a detection amount output from the measurement unit (1) and the threshold register (3). ) Is compared with the threshold value, and when the detected amount is between the threshold value and the predetermined value, the display unit (2) is deactivated, and the detected amount exceeds the threshold value in the predetermined direction. Sometimes, the display unit (2) is put into an operating state and the detection is performed. There measuring apparatus characterized by comprising comparison means (4) for controlling so as to be displayed. 2. The measuring device according to claim 1, wherein the display unit includes a pilot lamp (23) that is turned on when the comparison unit (4) is controlled to be in a non-operation state.