JPS5892910A - Magnetic graduated scale - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a method of moving the reading head or scale plate facing a fixed scale plate or reading head and sequentially reading scales attached to the scale plate with the reading head. This relates to a magnetic scale that measures the amount of movement of a plate.

Conventionally, optical measuring devices, such as optical A table measuring device that can measure up to a minimum of 1 μm by using a reader (product name) or a ring-shaped magnetic head arranged at equal intervals and the corresponding signal size, such as the Sony Magnescale (product name) or a laser with a fixed wavelength. There are laser measurement devices that use light, but these measurement devices have a complicated structure, which makes installation, adjustment, handling, etc. troublesome.

In order to eliminate the drawbacks of the conventional example, the present invention provides a magnetic scale consisting of a scale plate with a multi-track magnetic scale and a reading head in which a plurality of magnetically sensitive elements are arranged in one row. It is something to do. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention, and FIG.
The figure shows an example of the arrangement of scales on a scale plate according to an embodiment of the present invention.
The figure is a side view of one embodiment of the present invention. Reference numeral 1 denotes a reading head that is movable, for example, in the direction of arrow A;
Five magnetically sensitive elements, such as magnetoresistive elements (not shown), are arranged at equal intervals in a direction perpendicular to the direction of movement on the front surface of the apparatus. 2 is a substrate 3 made of a non-magnetic material, such as quartz glass or special alloy, which has a small coefficient of thermal expansion and can easily obtain parallelism and flatness;
, the main scale 4 is set at a constant interval a in the direction of movement of the reading head 1.
Each of the tracks 5 and 7 has one main scale track 5 arranged as shown in FIG.
By shifting the positions of scales 4 and 6 by a15 in the direction of movement of the reading head 1, a scale plate (second
(see figure), the multi-track scale 8 of this scale plate 2 is
A ferromagnetic i-material, for example, Fe-N1-, is deposited and formed on the surface of the substrate 3 in accordance with the pattern of the multi-track scale 8.
This is a film made of AI-Co-Cu (newly 8 steel-alnico) that is magnetized. Reference numeral 9 denotes a level comparison circuit that amplifies the signal read from the scale plate 2 by the reading head 1, and an amplifier 110 that compares the levels of the signals output from the amplifier 9 to operate the counter 11. Reference numeral 12 denotes a display device.

In this embodiment configured in this way, when the reading head 1 is moved while maintaining the distance between the reading head 1 and the scale plate 2 (see FIG. 3), the magnetoresistive element of the reading head 1 is From the main scale 4 of the shaku track 5, the sub scale 6 of the first vernier track 7, second vernier track 7, third vernier track 7, and fourth vernier track 7 are sequentially read from the repeating table. .

Therefore, the number m of main graduations 4 read from the main scale track 5
By comparing and determining which (n) magnetoresistive element among the four magnetoresistive elements that read the subscale 6 from the vernier track 7 is outputting a signal, the movement 1 of the reading head 1 can be determined.
1, that is, the length 1 of the object to be measured is 1 = (mX, a) + (nx+), and this value is displayed on the J display device 12.

Incidentally, the reading head 1 may be fixed and the scale plate 2 may be moved to measure the amount of movement of the scale plate 2.

Furthermore, if the number of magnetoresistive elements arranged in the read head 1 is increased, the measurement accuracy will be increased. Further, the vernier track 7 is arranged such that the interval between the scales of adjacent tracks is at least 2 a/n in order to prevent the scales of the track to be read and the scales of adjacent tracks from interfering with each other. Fourth
They may be arranged as shown in the figure.

As explained above, according to the present invention, the structure is simple, so there is an advantage that installation, adjustment, and handling are easy. Additionally, since the multi-track scale on the scale plate is formed by depositing a highly magnetic material on a non-magnetic substrate, the scale can be shaped by trimming or other means, which has the advantage of increasing measurement accuracy. There is.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the configuration of an embodiment of the present invention, FIG. 2 is an example of the arrangement of scales on a scale plate of an embodiment of the present invention, and FIG. 3 is a side view of an embodiment of the present invention. FIG. 4 shows another example of the arrangement of the scales on the scale plate according to the embodiment of the present invention. 1...Reading head, 2...
...Scale plate, 3...Base board, 4...
...Main scale, 5...Main 1-shaku track, 6...Sub scale, 7...
...Vernier track, 8...Multi-track scale. Patent applicant: Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] Moving the reading head or the scale plate facing the fixed scale plate or reading head, respectively, and sequentially reading the scales attached to the scale plate from the front with the reading head,
In a scale for measuring the amount of movement of the reading head or the scale plate, the scale plate has one main track in which main scales are arranged at a constant interval a in the direction of movement, and subscales in the direction of movement. (n - 1) vernier tracks arranged at a constant interval a equal to the main scale, the position of the scale of each track is sequentially shifted by a/n in the movement direction, and A multi-track scale arranged in a vertical direction is applied to a non-magnetic substrate by means of a magnetized magnetic material. A magnetic graduation scale characterized by being arranged in a row at regular intervals in the direction.