JP2001141433A - Rotation angle detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transmitting-type optical rotation angle detecting device which is capable of being formed thin and compactly. SOLUTION: A light emitting element 101 and a light receiving element 102 are connected onto one flexible wiring board 104 composed of a polyimide resin layer 105 and a metal wiring layer 106. By bending and raising a part of the flexible wiring board 104, the light emitting element 101 and the light receiving element 102 are arranged at locations opposite to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In order to control a rotating mechanism incorporated in a control motor, a robot arm, a precision automatic stage device, a printer device, a pointer-type clock device, a pointer-type instrument, etc., the operation rotation angle or rotation speed is precisely controlled. Detect
The present invention relates to a rotation angle detecting device generally called an encoder for converting into an electric signal.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional rotation angle detecting device. An optical rotation angle detecting device generally called an encoder includes a rotating disk type encoder scale 203 coupled to a rotating shaft 212, a light emitting element 201, and a light receiving element 20.
It comprises a detection head section having two pairs. On the encoder scale 203, a radial lattice pattern 218 (grating) for detecting a rotation angle is drawn in a slit shape. The encoder scale 218 may be a metal plate that has been slit-shaped by an etching method or the like,
A transparent glass plate or the like on which a lattice pattern is printed by a photolithography technique is used.

As the light emitting element 201, a light emitting diode or a semiconductor laser is used. As the light receiving element 202, a photo diode or a photo transistor is used. The light emitting element 201 and the light receiving element 202 need to be arranged opposite to each other so that the light emitted from the light emitting element 201 passes through the slit of the encoder scale 203 and reaches the light receiving element 202. Therefore, in the prior art, as shown in the figure, a structure in which the light emitting element 201 and the light receiving element 202 are pointed and fixed using the detection head frame 231 such as a resin molded member. Alternatively, these elements, the encoder scale, and the components are housed in a metal or resin molded housing.

[0004] Further, as wiring for power supply and signal output to the light emitting element 201 and the light emitting element 202, a metal terminal connected to the element is led out of the housing as a lead wire 232, or is connected to the element. The structure was such that a flexible wiring board was further joined to the connected metal terminals and pulled out of the housing.

[0005]

In the structure of a conventional rotation angle detecting device, a structure in which a light emitting element and a light receiving element are supported and fixed by a resin-made molded product or a metal support structure so as to be opposed to each other. Therefore, there is a limit to miniaturization and thinning for incorporating in small devices such as wristwatches, and since the mold required to manufacture a resin or metal housing is extremely expensive, The initial investment for manufacturing was large, and it was difficult to reduce costs.

In the prior art, since each lead wire 232 has a three-dimensional arrangement that is not on the same plane as shown in FIG. 6, it is connected to an electronic circuit board for performing signal processing and control. In order to achieve this, it is necessary to perform three-dimensional wiring, which also makes it difficult to reduce the size and cost.

[0007]

As shown in FIGS. 1 and 2, a light-emitting element 101 and a light-receiving element 102 are connected on a single flexible wiring substrate 104 composed of a polyimide resin layer 105 and a metal wiring layer 106. The angle detecting device is configured by bending and raising a part of the flexible wiring board 104 and disposing the light emitting element 101 and the light receiving element 102 at positions facing each other.

The light emitting element 101 and the light receiving element 102, which are originally minute elements, are directly mounted on the flexible wiring board 104 without being housed in separate packages and without adding individual lead wires and the like. Is possible. In addition, the flexible wiring board 1
The mask 04 is generally inexpensive as compared with a resin-molded mold, so that the initial investment is small. further,
Because of a simple configuration that does not require a substrate other than the flexible wiring substrate 104 or a wiring material, it is possible to reduce material costs and assembly costs. Note that in the case where a driving circuit or a signal processing circuit is necessary for the operation of the light-emitting element 101 or the light-receiving element 102, a semiconductor integrated circuit 112 in which these circuits are integrated can be connected to the same flexible wiring board 104. The entire device can be reduced in size and cost.

When the angle detecting device having the above configuration is incorporated in small devices such as a servomotor and a wristwatch, as shown in FIG. 5, the angle detecting device is bent inside a frame 124 or a housing for supporting a bearing 127 of the device. It is sufficient that the flexible wiring board 104 is sandwiched therebetween, and it is not necessary to provide a special frame or housing for supporting and fixing the angle detection device.

In order to constitute a reflection-type rotation angle detecting device, the light emitting element 101 and the light receiving element 102 may be arranged and connected in parallel to the flexible wiring board 104, and need not be bent.

[0011]

FIG. 1 shows an embodiment of the present invention. The embodiment includes a light emitting element 101, a light receiving element 102, and a flexible wiring board 104. In the embodiment, the light emitting element 1
01 is a light emitting diode (LED), a light receiving element 10
A phototransistor was used as 2. The flexible wiring board 104 includes a polyimide resin substrate 105, which is a flexible material, a metal wiring layer 106, and an insulating protection layer 107. The portion where the light emitting element 101 and the light receiving element 102 are connected exposes the metal wiring layer 106, so that the insulating protection layer 10
7 has an open window.

The light emitting element 101 and the light receiving element 102 are formed by bonding a semiconductor element on a metal lead frame 108. The lead frame is connected to the flexible wiring board 104 by reflow soldering. Light emitting element 1
01 and the light receiving element 102 are molded with a transparent sealing material 109 for protection. Note that a microlens 110 for condensing light was used to improve the sensitivity of the light receiving element.

An electronic circuit for driving the light emitting element 101 and an electronic circuit for amplifying and removing noise components from the signal of the light receiving element 102 and performing arithmetic processing may be required. In such a case, as shown in FIG. 2, a light emitting element 101, a light receiving element 102, a semiconductor integrated circuit 112 in which a drive circuit, a signal amplifier circuit, an arithmetic circuit, and the like are integrated may be connected on the same flexible wiring board 104. . According to this method, it is not necessary to use an extra circuit board or a wiring member. Therefore, it is possible to further reduce the size and cost of the device incorporating the rotation angle detecting device.

The encoder scale 103 intermittently intermits the light emitted from the light emitting element 101 with the rotation thereof and receives the light by the light receiving element 102. 11
8 is engraved. Since light emitted from the light emitting element 101 passes through the encoder scale 103 and is received by the light receiving element 102, a thin metal sheet is formed on the flexible wiring board 104 as shown in FIG. Although the position can be fixed by backing and attaching the plate 113 or the like and bending and raising the flexible wiring board 104, as shown in FIG. 5, a frame that supports a motor, a gear, or a bearing 122 of the encoder scale 103. 1
14 or a case. As a fixing method, the frame 114 and the flexible wiring board 1 are used.
04 may be bonded, or a protrusion provided on the frame 114 may be combined with a hole provided on the flexible wiring board 104.

FIG. 5 shows an embodiment in which the rotation angle detecting device of the present invention is incorporated to detect the rotation angle of the pointer of an information display device such as a wristwatch or a gauge. Attach encoder scale 103 to shaft 122 for rotating pointer 125,
The detection head of the rotation angle detection device is sandwiched and fixed in the gap between the frame 114 (base plate) that supports and fixes the bearing of the shaft 122 of the pointer 125. By the same method, the calendar mechanism of the timepiece device and the rotation angle detecting device according to the present invention can be reduced in size and thickness, and can be incorporated into a small precision device such as a wristwatch having an extremely small internal space.

[0016]

The detection head of the rotation angle detection device is supported.
A frame or a case for fixing, and an extra board or wiring member are not required, so that the thickness and the size can be reduced, and the cost can be reduced. Furthermore, by mounting on a flexible wiring board, it is possible to supply in the form of tape and reel used in mass production automatic manufacturing machines,
Mass productivity is improved.

In addition, the present invention makes it possible to reduce the thickness and size of the rotation angle detecting device, even if it is a micro motor or wristwatch that is too large to be incorporated with the conventional rotation angle detecting device. Has made it possible to incorporate them.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention.

FIG. 2 shows an embodiment of the present invention.

FIG. 3 shows an embodiment of the present invention.

FIG. 4 shows an embodiment of the present invention.

FIG. 5 shows an embodiment of the present invention.

FIG. 6 shows a rotation angle detecting device according to a conventional technique.

DESCRIPTION OF SYMBOLS 101 Light emitting element 102 Light receiving element 103 Encoder scale 104 Flexible wiring board 105 Polyimide resin substrate 106 Metal wiring layer 107 Insulation protection layer 108 Lead frame 109 Transparent sealing material 110 Micro lens 111 Metal wiring 112 Semiconductor integrated circuit 113 Connection Terminal 118 Lattice Pattern 122 Rotation Axis 123 Metal Plate 124 Frame 125 Pointer 126 Dial 127 Bearing 201 Light Emitting Element 202 Light Receiving Element 203 Encoder Scale 208 Lead Frame 209 Transparent Sealant 218 Grid Pattern 222 Rotation Axis 231 Detection Head Frame 232 Lead wire 233 Mounting flange

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Claims (5)

[Claims] 1. A transmission type optical rotation angle detection device having a pair of a light-emitting element and a light-receiving element installed opposite to each other and a disk-shaped encoder scale, wherein a resin substrate and a metal wiring layer are provided. A light-emitting element and the light-receiving element are connected together on one flexible wiring board composed of: a position where the light-emitting element and the light-receiving element face each other by bending a part of the flexible wiring board; A rotation angle detection device, wherein the rotation angle detection device is arranged in a position. 2. An electronic circuit for driving the light-emitting element and a semiconductor integrated circuit for amplifying a signal output from the light-receiving element, removing a noise component, or performing arithmetic processing, etc., are installed and connected to the flexible wiring board. 2. The rotation angle detection device according to claim 1, wherein: 3. The timepiece according to claim 1 or 2, wherein the time is displayed by a rotation angle of a mechanical pointer, and the rotation angle of a gear or an encoder scale connected to a rotation shaft for driving the pointer. A timepiece device, wherein a display rotation angle of the hands is controlled by detecting the time using an angle detection device. 4. A timepiece device having a calendar mechanism for displaying a date or the like according to a display rotation angle of a rotating disk,
The indication of the hands by detecting a gear pattern engraved on the rotating disk or a rotation angle of a gear or an encoder scale connected to the rotating disk using the angle detecting device according to claim 1 or 2. A timepiece device characterized by controlling a rotation angle. 5. An information display device for displaying a physical quantity such as voltage, current, pressure or the like by a display rotation angle of a mechanical pointer, wherein a rotation angle of a gear or an encoder scale connected to a rotation shaft for driving the pointer is provided. 3. An information display device, wherein the display rotation angle of the hands is controlled by detecting using the angle detection device according to claim 1 or 2.