JPS5828179Y2 - rotary encoder - Google Patents

Description

[Detailed description of the invention] This invention is a rotary encoder, more specifically, a desired angle θ.
This relates to a rotary encoder that generates a number of pulses proportional to the shθ button and part θ by rotating it.
For example, it is used in planimeters, drawing instruments, etc.

As a conventional device of this type, for example, Japanese Patent Application No. 48-134134
The inventor of the present invention has already filed an application for the No. 1, but in this conventional one, the second scale plate is moved parallel to the fixed first scale plate, so the first scale plate becomes large. In order to improve measurement accuracy, a scale plate with a width of 25 μm must be formed on the scale plate, but since the lines are thinner and the area of the scale plate is large, it becomes expensive.

The present invention solves this problem by providing a pair of first and second scale plates so as to be able to rotate at equal angles in the same direction. A first scale line and a second parallel scale line perpendicular to the first scale line are provided in an annular manner, and the mutually parallel scales are made to interfere with each other to generate a pulse proportional to 5ilOb and θ of the rotation angle θ of the scale plate. It is designed to be detected.

An embodiment of the present invention will be described in detail below with reference to the drawings.

As shown in Figures 1 and 2, a pair of first and second shafts 2 and 3 are supported in the housing 1 so as to rotate vertically by bearings 4 and 4 pivots 5° and 6.1, respectively. 3 are connected via gears 8, 9 and an intermediate gear 11 fixed to a shaft 10, and are connected so as to rotate at equal angles in the same direction.

When the present invention is applied to a planimeter, linear wheels 12 and 13 are fixed to both sides of the housing 1, and a measuring rod 14 for tracing a figure is fixed to the upper end of the shaft 2.

Shafts 2 and 3 are pulleys or belts instead of intermediate gears,
They may be connected by a wire or the like so that they rotate at equal angles in the same direction.

In FIG. 3, 15 is a frame that supports the shaft 10 of the intermediate gear 11, and 16 and 17 are the same pivots.

As shown in the second and fourth figures, the shafts 2 and 3 are made of glass, for example.
The first and second scale plates 20.21 made of a transparent material such as plastic are fixed, and the first and second scale plates 20.21 are fixed.
Parallel first scale lines 23 and 24 as shown in the fourth figure are provided in an annular shape at positions where they overlap each other on the outer periphery of the scale.

Further, on the innermost and outermost peripheries of the first and second scale plates 20.21, there are vernier scale lines each having a phase difference of one period leading, to, and after the first scale line 23.24. 23a.

24a is provided in an annular shape.

On the first and second scale plates 20.21, second scale lines 25.26 are circularly arranged in a direction perpendicular to the first scale line 23.24 and parallel to the first scale line 23.24. establish.

On the inside and outside of the second scale lines 25, 26, vernier scale lines 25a, 26a are provided annularly, leading and trailing by one period, respectively.

As shown in the third figure, a lens 30 and a light source 31 are fixed by a frame 32 below the weight portions of the first and second scale plates 20 and 21, and above them a pair of phototransistors 33, 34, 34a.

33a is fixed by a frame 35, and a light shielding plate 36.
36...... is fixed.

Since the present invention has such a configuration, when the shaft 2 rotates by an angle θ, the shaft 3 also rotates in the same direction and by the same angle.

Therefore, the overlapping portions of the scale plates 20.21 operate at the same angle in opposite directions in the vertical direction of FIG. 4, but as shown in FIG. Since they are tilted at an angle θ in the same direction and their rotation angles are equal,
The first scale lines 23.23a and 24, 24a and the second scale lines 25.25a, 26, 26a are always kept parallel to each other, and both are 2sinθ and 2COSθ [strictly speaking, 2(1-COSθ)]. Move relatively by a proportional length.

Therefore, the light passing from the light source 31 through the lens 30 and passing through the first scale lines 23.23a and 24.24a has a 2si
Moiré interference fringes proportional to nθ are generated, and the phototransistors 33 and 33a generate a number of pulses proportional to 2sinθ.

Also, the second scale line 25 is displayed from the light source 31 through the lens 30.
The light passing through ゜25a and 26.26a generates moiré interference fringes proportional to 2CO8θ, and the phototransistor 3
4.34a generates a number of pulses proportional to 2COSθ.

In the above embodiment, the diameters of the first and second scale plates 20°210 are equal, but they do not necessarily have to be equal.

At this time, the overlap between the two is 2 sin θ. 2CO8θ
They operate on each other at higher magnifications.

As described above, in the present invention, since the first button and the second scale plate are provided with the first and second scale lines that are perpendicular to each other, it is possible to trace signals proportional to sin θ and part θ. Since the processing of the signal becomes easy, the capacity of the calculator and calculation time can be saved, and the quadrant can be determined by comparing both signals, so there is no need to obtain a signal for quadrant determination. Since the mechanical structure is also simpler than that of a three-axis type, the device can be made smaller.

In addition, since the overlapping portions of the first and second scale plates operate in opposite directions, it is possible to generate pulses proportional to sin θ and 弼 θ with an accuracy more than twice that of conventional ones, which not only allows for precise measurements, but also The size of the scale line can be increased to 50 μm, for example, and therefore the scale line can be formed at low cost, and the device can also be made smaller.

[Brief explanation of drawings]

Figure 1 is a plan view 1 of an embodiment of the present invention, and Figure 2 is its A.
3 is a sectional view taken along the line B-B, FIG. 4 is an enlarged explanatory plan view of the scale plate, and FIG. 5A is a sectional view of the scale plate 20.
21 is an explanatory diagram showing the scale lines 23.24 before rotation, and the opening is an explanatory diagram showing the tilted state of the scale lines 23.24 after the scale plate 20.21 is rotated. 20.21...Scale plate, 23.24...
・First scale line, 25, 26... Second scale line.

Claims (1)

[Claims for Utility Model Registration] A pair of first and second scale plates are provided to rotate equiangularly in the same direction, and each of the first and second scale plates has a parallel first scale line and a second scale plate. A second parallel parallel direction orthogonal to that
The scale lines are provided in an annular shape, and some of the parallel scales are made to interfere with each other, so that the rotation angle θ of the scale plate is 4n.
os- and cm. A rotary encoder characterized by detecting pulses proportional to .