JPS6082901A - Digital tape measure - Google Patents

Abstract

PURPOSE:To display surely length without errors by magnetizing a magnetic material layer provided on one surface of a long-sized body for measuring length to different states, detecting the magnetized states with a detecting part into which a Hall element is incorporated, calculating the detected states and converting the same to length. CONSTITUTION:The layer of a magnetic material provided as a surface extending over roughly the entire part in the longitudinal direction of a long-sized body B is magnetized. For example, the magnetic material layer is segmented by each unit length (x) along the longitudinal direction (z) of the long-sized body from a reference line (y) and the inside of the first region is magnetized to the state N-S. The inside of the 2nd region is then magnetized to the state S-N. The magnetic material layer is thus alternately magnetized to different states by each of the unit length (x) to constitute a row 1. The row 2 is segmented by each unit length 2x along the longitudinal direction of the long-sized body from the line (y). The inside of the first region is magnetized to the state N-S and the inside of the next region is magnetized to the state S-N to constitute said row. The row 3 is similarly magnetized by making the unit length 4x. The digital tape measure is thus constituted by magnetizing generally the rows (n) to the alternately different states with 2<(n-1)>x as the unit length.

Description

[Detailed description of the invention] This invention relates to a digital tape measure.

A digital tape measure is a length measuring device that is rolled around a core and housed in a case. When you pull it out of the case and place it on the object to be measured, you can measure the length without having to read the scale. It is a tape measure that is automatically displayed as a numerical value.

In conventional measuring tapes, scales are attached to a length-measuring elongate body, and measurements are carried out by placing the elongate body over the object to be measured and reading the scales on the elongate body. With this method, it was easy to misread the scale, and it was difficult to measure length in a dark place. Therefore, an attempt was made to have a machine read the scale and display the read value as a numerical value.

One of the attempts is the Japanese Patent Application Publication No. Shojj;
It is stated in the No. In this publication, a magnetic material is coated on the surface of a long body for length measurement in a tape measure, and a non-magnetic material is coated on top of it at equal intervals corresponding to the length measurement scale, and the magnetic material and non-magnetic material are appear alternately at regular intervals, and when pulling out the elongated body from the case,
It is proposed to calculate the number of regions of magnetic material and non-magnetic material and display the length as the sum of the numbers. in particular,
In order to count the number of regions of magnetic material and non-magnetic material, a magnetic detector is installed close to the elongated body.

A magnetic detector generates a voltage when a magnetic material moves in front of it, but does not generate a voltage when a non-magnetic material moves in front of it, so we decided to count these repeated pulses and display the number to determine the length. There is.

However, the method taught in this publication has the disadvantage that if the elongated body is pulled out at a high speed, errors in counting are likely to occur, and therefore accurate measurements cannot be made. Also, depending on this method, after storing the long body in its original state,
The length will not be calculated unless you pull it out again.

Therefore, it is necessary to pull out the long object from the beginning every time a survey is carried out. Therefore, there was a drawback that length measurement was cumbersome.

The inventor attempted to improve the above-mentioned drawbacks. The inventor followed the teachings of the above-mentioned publication in applying the magnetic material to the surface of the elongated body, but completely changed the state of magnetization. That is, the surface coated with the magnetic material is divided in the width direction to form a plurality of magnetization rows extending in the longitudinal direction, a Hall element is provided adjacent to each magnetization row, and each Hall element is made to detect the magnetization state. Take this as a signal,
An attempt was made to display the length by calculating this signal. As a result, we confirmed that the length could be displayed accurately. This invention was made based on such confirmation.

This invention provides a length measuring elongated body which is rolled around a core body and housed in a case, a magnetic material layer is provided on the negative side of the length measuring body, and the magnetic material layer is divided into n rows extending in the longitudinal direction and magnetized. In addition, each row is divided into unit lengths, and the unit lengths that are in momentary contact are magnetized in different states, and the unit lengths are made different between rows to obtain the minimum scale unit, (, -> and twice that, 1g times... ...2x, a detection section is attached close to each row within the case, the magnetization state of each row is detected by a Hall element built into each detection section, and the result is sent as a signal to a decoder or computer. This invention relates to a digital tape measure that is characterized in that it is calculated in a decoder or computer and displays the length of a drawn-out portion of a long body as a numerical value.

An example of the implementation of this invention will be described below based on the drawings. FIG. 1 is a front view of a digital tape measure according to the present invention, and FIG. 2 is a sectional view taken along the line ■-■ in FIG. FIG. 3 is a model diagram showing the magnetization state of the length measuring elongated body of the tape measure according to the present invention. FIG. 2 is an explanatory diagram showing the relationship between the magnetization state and the detection section in the tape measure of the present invention. FIG. 5 is a model diagram showing the relationship between the position of the detection unit and the signal.

In Figures 1, 2, A is a tape measure case, B is a length measuring elongate body, 0 is a core body, D is a guide, E is a detection unit incorporating a Hall element, and F includes a decoder or computer. In the electronic circuit section, G is a digital display section. The tape measure according to the present invention is disclosed in Japanese Patent Application Laid-Open No. 6-1999 in that it is equipped with each of these parts. It is similar to the one described in the f-7,22/θ3 publication, but the magnetization state of the magnetic material in the elongated body B and the structure and function of the detection unit E and decoder or computer F related thereto are different. I have to.

The material of the length measuring elongated body used in this invention may be a belt-shaped body made of non-magnetic steel (for example, SUS jθ stainless steel), or a belt-shaped body made of synthetic resin reinforced with glass fiber. It may be the body. Its width is 5~da θu1 thickness 0.01-0. j) Codfish with a length of 7 to 209 m can be used. The elongated body used in the present invention is made of such a material and has a layer of magnetic material provided on at least one surface thereof. A magnetic material is a material that can be magnetized, such as ferrite powder. The layer of magnetic material is provided, for example, by mixing powder of magnetic material with a suitable paint and applying the mixture. The magnetic material layer can be provided by a known method that is generally used in manufacturing magnetic tapes and the like. In this way, the layer of magnetic material is formed as a surface extending over substantially the entire length of the elongated body.

In this invention, the layer of magnetic material provided as described above is magnetized. When magnetizing, the elongated body is magnetized in several rows extending in the longitudinal direction, so that a magnetized state divided into a plurality of rows, especially many rows, is formed. Furthermore, each row is divided into unit lengths corresponding to graduations, and the divided regions are made to have the same magnetization state, while adjacent regions are made to have different magnetization states. Also, for the unit length between different columns, twice the minimum unit length,
(n-1) Da times...2 times the relationship.

The relationship between the unit lengths is specifically illustrated in FIG. 3. In FIG. 3, / to j respectively indicate the magnetization states of seven columns.

The column / is divided into unit lengths X along the longitudinal direction 2 of the elongated body from the reference my. Then, the first region is magnetized to the N-5 state. The magnetized region in this state is indicated by diagonal lines. Next, the second region adjacent to this is magnetized in a state different from that in the first region, for example, S
- Magnetized to H state. The magnetized region in the SN state is shown without hatching. The inside of the third region is magnetized to the N-3 state similarly to the inside of the first region. thus,
Each unit length X is alternately magnetized to a different state to form a row/.

The column is along the longitudinal direction 2 of the elongated body from the reference May,
Divide into unit lengths of 2x, and divide this into N-S in the first area.
It is magnetized to the state of , and the next region is magnetized to the state of S-H. Column ko has a unit length of 2 compared to column /.
The only difference is that it is doubled.

Next, the column J is magnetized in the same manner as the above-mentioned columns/and C, with the unit length being DaX. In addition, the unit length of the column is koX,
The magnetization is 0-1) in the same manner as in the above-mentioned rows/ to 3. Thus, in general, arrays n are constructed by having a unit length of 2 x and being alternately magnetized to different states.

The unit length X, expressed as an absolute value, can be selected from a value in the range of Q, θ/, and/or Omm.

Also, the number n of columns is preferably as large as possible, but due to the width of the Hall element H, /M! The value is within the range of 0.

In this invention, since the elongated body is divided into n rows and magnetized, a detection section is attached to each row. A detection unit is attached adjacent to each column. The degree of proximity is 0 in terms of distance,
It is a distance of 0j to / dew.

These detection units are arranged side by side with the Hall elements therein facing in the longitudinal direction of the elongated body. These Hall elements are housed in the detection section E shown in FIG.

The mechanism by which the Hall element H senses the magnetization state is as follows. In FIG. 7, the detection unit B approaches the elongated body B.
When / is attached, the detection part E
A magnetic flux current J is generated within /.

That is, when the magnetization state region N-8 comes directly below the detection part IC/, a magnetic flux is generated that flows in the direction of the arrow P, and a voltage is generated in the Hall element H in accordance with the flow of this magnetic flux.

However, when the oppositely magnetized S-H magnetization state region comes, a magnetic flux flows in the direction of arrow Q, and
According to the flow of this magnetic flux, a voltage opposite to the previous voltage is generated in the Hall element (2).

As a result, a positive or negative voltage is produced on the voltmeter V, respectively. This voltage is sent as a signal to a decoder or computer F. Based on this, calculations are performed within the decoder or computer 1.

Within the decoder or computer F, calculations are carried out according to the principles described below. FIG. 5 shows a part of the elongated length measuring body B similar to that shown in FIG. 3 in an enlarged manner. In FIG. 5, the tip of the detection section IIi/ is placed at the L position. At this time, since the detection section E/ on the column/top is located above the region magnetized in the state of S-H, magnetic flux flows in the direction of the arrow Q and a negative voltage is exhibited. Since the detection section on the column C is located above the region magnetized to the N-8 state, a magnetic flux flows in the direction of arrow P and a positive voltage is shown. Similarly, the detectors on column 3 exhibit positive voltages, the detectors on column Z exhibit positive voltages, and the detectors on column j exhibit negative voltages. In this way, at the position L, a combination of "negative, positive, positive, positive, negative..." is shown as a voltage. Such a combination is constant depending on the position of L. Then, this combination is guided to a decoder or computer F as a signal. In the decoder or computer F, this signal is converted from a binary value to /θ
It is converted into a base value and sent as a length value to the digital display section G, where it is displayed as a numerical value.

In the above, when one region is magnetized to the S-H state, the other region is magnetized to the H-S state in order to make each row have a different magnetization state. Not limited to. It is also possible to magnetize one region and leave the other region unmagnetized. Alternatively, one region may be strongly magnetized and another region may be weakly magnetized, and the magnetization may be differentiated based on the strength of magnetization.

According to the digital tape measure of the present invention, in the elongated body for length measurement, which is wrapped around a core body and housed in a case, a magnetic material layer is provided on the side thereof, and the layer is magnetized in different states. However, we decided to detect this magnetization state with a detection unit incorporating a Hall element installed close to the magnetic material inside the nurse, and calculate the detection result with a decoder or computer and convert it into length. The length is displayed as you pull the body out of the case. In addition, the magnetic material layer is divided into n rows extending in the longitudinal direction and magnetized, and within each row, adjacent unit lengths are magnetized in different states depending on the unit length, and furthermore, the unit lengths are different between the rows. Close it, the minimum scale unit and its twice S da times 12 times...-! (′-”) times, the combination of magnetization states in each row is different for each minimum scale unit.In other words, the magnetization state in each row is unique depending on its position on the elongated body. Therefore, by sending this relationship to a decoder or computer and calculating it, the length can be displayed as a numerical value.Thus, this tape measure generates a signal specific to the position on the long object. Since this is displayed as a length, the length can be displayed reliably without error.Furthermore, the display is easy to read because it is displayed as a numerical value on the digital display section. It has advantages.

[Brief explanation of drawings]

FIG. 1 is a front view of a digital tape measure according to the present invention, and FIG. 2 is a sectional view taken along the line ■--■ in FIG. FIG. 3 is a model diagram showing the magnetization state of the length measuring elongated body of the tape measure according to the present invention. FIG. 7 is an explanatory diagram showing the relationship between the magnetization state and the detection section in the tape measure of the present invention. FIG. 5 is an explanatory diagram showing the relationship between the position of the detection unit and the signal. In the figure, a person is a tape measure case, B is a long length measuring body, 0 is a core body, D is a guide, E is a detection unit including a Hall element, F is a decoder or computer, G is a digital display unit,
H is a Hall element. Also, / to 2 is a magnetization array. Figure 1 Figure 2 Figure 4 Figure 5

Claims (1)

[Claims] In a long body for length measurement which is rolled around a core body and housed in a case, a magnetic material layer is provided on the negative side of the length measuring body, and the magnetic material layer is divided into n rows extending in the longitudinal direction and magnetized. Within a row, adjacent unit lengths are divided into unit lengths, and adjacent unit lengths are magnetized in different states, and the unit lengths are made different between rows to obtain the minimum scale unit and 2 times, 7 times, etc., 2 (-゛) A decoder that doubles up and has a detection section attached close to each row within the case, detects the magnetization state of each row with a Hall element built into each detection section, and sends the result as a signal to a decoder or computer. Or a digital tape measure, which is calculated in a computer and displays the length of the drawer part of the elongated body as a numerical value.