JPS60169713A - Optical tachometer - Google Patents

Abstract

PURPOSE:To obtain a tachometer, which is connected by thin optical fiber cables, which do not impede the movement of the movable bent part of a robot device, by reducing the numbers of the optical fibers for incident light and the optical fibers for outputting received light. CONSTITUTION:In a rotary plate 1, an index slit 21, a B phase slit 22 and an A phase slit 23 are provided. The slits 22 and 23 are arranged at the same pitch so that the phases are shifted by pi/2. For example, white light is inputted by a piece of optical fiber 5 for inputting light. The light is split by a splitter 8 comprising spectral plates 62 and 63. The light having a wavelength lambda1 is coupled to an optical fiber 42 for outputting the received light through the slit 22. The light having a wavelength of lambda2 is coupled to an optical fiber 43 for outputting received light through the slit 23. The light having the measuring wavelengths, which has passed the spectral plates 62 and 63, is totally reflected by a total reflecting mirror 61 and coupled to an optical fiber 41 for outputting the received light. Thus the information of the rotary angle, the directivity of the forward or reverse rotation and the absolute position of the angle of the rotary plate 1 can be outputted to the optical fibers 41, 42 and 43.

Description

[Detailed description of the invention] Technical fields> The present invention relates to an optical rotation meter using an optical fiber.

<Prior Art> In recent years, an optical rotation meter as shown in FIG. 1 has been used as a detector for obtaining angle signals for drive control of rotating parts and bending parts of a rodet device. FIG. 1 is a side view of such an optical rotation meter, and FIG. 2 is a plan view showing the arrangement of slit rows on the rotary plate of the optical rotation meter shown in FIG.

In FIG. 1, l is a rotating plate, 21.2. , 2. 3 □, 32, 3 . are circumferential slit rows provided in the rotating plate 1 in a radial direction. is an input optical fiber that inputs the incident light ' into each slit row, 41 r 4. +
43 is an output optical fiber coupled to each slit row. As shown in FIG. 2, the rotary plate l has index slits, a B-phase slit row, and a facial slit row arranged from the inside in the radial direction.

Index slit 2. is a slit that provides information on absolute position determination of rotation angle. B-phase slit row 22 and human face slit row 2. Both have, for example, 1 m too slits, that is, slit rows arranged at the same pitch, but in the human phase and the B phase, the phase is, for example, V2 in the electrical angle of pulse generation.
It's out of alignment.

Therefore, depending on the direction of rotation, the phase delay at the rising edge of the received light pulse is different for the human phase and B phase, and is used to detect whether the rotation is normal or reversed.

In the conventional optical rotation meter shown in FIGS. 1 and 2, an input optical fiber 3 + 32 + 3B and an output optical fiber 7
1 r G + 43 A total of 6 optical fiber bundles are coupled through the slit row of the optical rotation meter ◇ Therefore, the cost increases and the optical fiber cable that accommodates these optical fiber bundles becomes thicker. This results in poor flexibility. Therefore, in a robot device in which a large number of such optical rotation meters are installed, a thick optical fiber cable is placed at the base, which hinders the mobility of the movable bending part of the robot device. This was not favorable in terms of drive control.

<Purpose of the Invention> The present invention was made in view of the above-mentioned deficiencies of the conventional example, and it is an optical rotation meter connected with a thin optical fiber cable that does not hinder the movement of the movable bending part of the robot device. The purpose is to provide

Means for Solving Problems〉 The configuration of the optical rotation meter according to the present invention that achieves the above object is as follows:
A rotary plate equipped with a row of slits arranged in a radial direction for detecting forward rotation, reverse rotation, and a reference point, a single light beam 7 for inputting light into the rotary plate, and a rotary plate provided in the vicinity of the rotary plate. ,
A splitter that is coupled to the optical fiber and branches the input light corresponding to the slit row, and a splitter that is split by the splitter, receives the light transmitted/blocked by each slit row independently for each slint, and outputs the light. It is characterized by consisting of a plurality of optical fibers.

<Example> An example of the optical rotation meter according to the present invention will be described with reference to the drawings.

FIG. 3 is a side view of the optical rotation meter of the present invention.

In FIG. 3, l is a rotary plate, and the slit arrangement value of this rotary plate l is the same as that shown in FIG.

That is, 2□r 21 + 2B is a slit row provided on the rotary plate l; is the index slit, 22 is B
Phase slit, 2. The A-phase slits, the B-phase slits 22, and the human face slits 23 are arranged at the same pitch, and the phases are shifted by %. 41yGr'j is a receiving output optical fiber, 5 is an input optical fiber, 6t+63+ is a half mirror or a spectroscopic plate, 61 is a total reflection mirror, 7o, 7s, 7t,
7B is a lens system for condensing light.

In addition, Half Mira 62, 6. In this embodiment, is a spectroscopic plate that reflects only light of a specific wavelength and transmits light of other wavelengths. In the optical rotation meter shown in FIG.
The incident white light, for example, passes through the spectroscopic plate 6. which constitutes the splitter 8. ,6. 1 by the total reflection mirror 61, and the light of wavelength λ1 is passed through the slit 2. The light with the wavelength λ is coupled to the receiving output optical fibers 4t and 4a via the slit 2s, and the remaining wavelength light that has passed through the spectrometer plates 6, 6s is totally reflected by the total reflection mirror 6I and passes through the slit 21. The light receiving output light is connected to the 4m optical fiber 4m and receives information about the rotation angle of the rotating plate, the forward/reverse direction of rotation, and the absolute position of the angle.'I+4.14
It can be output to j. Note that 56tr6& may be a /M 7 mirror that reflects a part of the incident light regardless of the wavelength. Note that when a spectroscopic plate is used, even if the optical fibers on the light receiving side are combined into one, the light can be divided into three output lights later by the spectroscopic plate, so it is possible to further reduce the number of optical fibers.

In the optical rotation meter according to the present invention, the number of input, light receiving and output optical fibers is only four in total, which can be reduced compared to the conventional one shown in FIG. The optical fiber cable that converges and wires these lights has become thinner, making it easier to install inside the device, reducing obstacles to flexibility at movable bending parts, and reducing the overall cost. The splitter 8 in the present invention is not limited to the one shown in Fig. 3.For example, in the embodiment shown in Fig. 4, the input optical fiber 5 is coupled to one splitter 8, 8 divides the incident light into three equal parts and connects them to three short optical fibers 9., 9.
,9. into the optical fiber 91. '9. ,9. The light branched into the light receiving side optical fibers 4I24□, 4. This is what is combined with t and output.

The embodiment shown in FIG. 4 also requires a total of four input optical fibers 5 and receiving optical fibers, and has the same effect as the embodiment shown in FIG. 3.

The optical rotating needle according to the present invention can be widely used for detecting the rotation and bending of robot machine tools, detecting the opening angle of valves, rotating machine tools, and as tachometers for vehicles.

<Effects of the Invention> According to the optical rotating needle according to the present invention, the number of input optical fibers and optical fibers for receiving and outputting light can be reduced compared to conventional ones, so that it is possible to reduce the number of optical fibers with the necessary optical fiber bundle. The thickness of cables has become thinner, and it has become possible to use cables with greater flexibility. Therefore, when the optical rotating needle according to the present invention is used to measure the angle of a rotating part or a bent part of a robot machine tool, it becomes easy to wire the optical fiber cable in the robot machine tool. The influence of the weight of the optical fiber cables wired in the drive control of the robot's arms, etc. is reduced, and the drive control of the robot machine tool is not hindered, allowing accurate operation at all times and improving the reliability of the equipment. Became.

According to the optical rotating needle of the present invention, the number of optical fibers used for input and light reception and output is reduced, so the optical fiber cable can be an inexpensive one with a small number of optical fiber cores i.
This makes it possible to reduce costs, especially for equipment with many optical rotating needles and a large amount of optical fiber cables used.

[Brief explanation of drawings]

FIG. 1 is a side view of a conventional optically rotating needle, FIG. 2 is a plan view of a rotating plate of the optically rotating needle shown in FIG. 1, and FIG. 3 is a side view of an embodiment of the optically rotating needle according to the present invention. FIG. 4 is a side view of another embodiment of the invention. In the drawings, I is a rotating disk, 2□, 2□, 2. is a slit row, 3, , 32.3. is the input optical fiber, 41,4□,
43 is an optical fiber for receiving and outputting light, 61 is a total reflection mirror, 62 and 63 are half mirrors or splitting plates, 70y71+
7□, 7. is a lens system, 8 is a splitter, 9I, 9□, 9. is Optical Fino 5. Patent applicant: Sumitomo Electric Industries, Ltd. Patent attorney: Shibu Mitsuishi (and 1 other person)

Claims (3)

[Claims] (1) A rotary plate equipped with a row of slits arranged in a radial direction for detecting forward rotation, reverse rotation, and a reference point, an optical fiber that inputs light to the rotary plate, and a connection to the optical fiber. a splitter that branches the input light corresponding to the slit rows, and a plurality of optical fibers that independently receive and output the light split by the splitter and transmitted/blocked by each slit row for each slit. An optical rotation meter that is characterized by: (2) The optical rotation meter according to claim 1, wherein the branching device is formed of a half mirror or a spectroscopic plate and a total reflection mirror. (3) The optical rotation meter according to claim 1, characterized in that each slit row of the rotary plate and the branching device are connected by short individual optical fibers.