JP2000018972A - Optical encoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable reduction of the number of parts items, reducing a part mounting area, reducing the manufacturing process, lowering cost, and improving reliability by forming a photodetector device, an analog signal processing circuit and a digital signal processing circuit on the same substrate to make an application specific integrated circuit(ASIC). SOLUTION: An encoder signal 1a from a photodetector device 1 receiving a light 1A is input to an analog signal processing circuit 9A, and an output 9Aa thereof is output as a digital encoder signal 9a digitized through a digital signal processing circuit 9. The photodetector device 1, the analog signal processing circuit 9A, and the digital signal processing circuit 9 are each formed of an ASIC, for which the whole is formed in the same substrate 2 as a single ASIC. Accordingly, the photodetector device 1, the analog signal processing circuit 9A, and the digital signal processing circuit 9 are formed on the substrate 2 as an ASIC, or the substrate 2 itself is formed by a silicon substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical encoder, and more particularly, to an optical encoder in which a light receiving element, an analog signal processing circuit and a digital signal processing circuit are mounted on the same substrate.
The present invention relates to a novel improvement for forming a specific IC (hereinafter, referred to as an ASIC), reducing the number of components, reducing the component mounting area, reducing the number of manufacturing steps, reducing the cost, and improving reliability.

[0002]

2. Description of the Related Art As an optical encoder of this type which has been conventionally used, for example, as shown in FIG. 2, a light receiving element 1 of an encoder 10 has a light 1A which enters through a code plate (not shown). And outputs an encoder signal 1a.
This encoder signal 1a is formed by an analog signal processing circuit 9A and an ASIC which are composed of a comparator 3, resistors 4, capacitors 5, 6, a transistor 7, and an operational amplifier 8, which are electrical components of a substrate 2 constituting a signal processing circuit. The digital encoder 9 outputs a digital encoder signal 9 a via the digital signal processing circuit 9.

[0003]

Since the conventional optical encoder is configured as described above, there are the following problems. That is, since the light receiving element is provided in the encoder away from the substrate, the light receiving element and the substrate must be connected by a lead wire or a pattern,
The size of the encoder has been increased and assembly has not been easy. In addition, the analog signal processing circuit has to use many independent discrete electric components, so that it is difficult to reduce the size and it is extremely difficult to improve the reliability.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In particular, a light-receiving element, an analog signal processing circuit, and a digital signal processing circuit are provided on an ASI
It is an object of the present invention to provide an optical encoder which is formed as C, reduces the number of components, reduces the component mounting area, reduces the number of manufacturing steps, reduces the cost, and improves the reliability.

[0005]

An optical encoder according to the present invention is an optical encoder which outputs an encoder signal output from a light receiving element as a digital encoder signal via an analog signal processing circuit and a digital signal processing circuit. The light receiving element, the analog signal processing circuit and the digital signal processing circuit are formed on the same substrate to form an application-specific IC.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the optical encoder according to the present invention will be described below with reference to the drawings.
The same or equivalent parts as those in the conventional example will be described using the same reference numerals. In FIG. 1, reference numeral 1 denotes light 1A.
The encoder signal 1a from the light receiving element 1 is input to an analog signal processing circuit 9A, and the output 9Aa from the analog signal processing circuit 9A is input to the digital signal processing circuit 9, The digital signal processing circuit 9 outputs a digitized digital encoder signal 9a.

The light receiving element 1, the analog signal processing circuit 9A and the digital signal processing circuit 9 are all known ASs.
It is formed of an IC, and the whole is formed as one ASIC on the same substrate 2. Therefore, the light receiving element 1, the analog signal processing circuit 9A, and the digital signal processing circuit 9 are formed on the substrate 2 by an ASIC, or the substrate 2 itself is formed by a silicon substrate. The encoder signal 1a
Is applicable to both the rotary type and the linear type.

[0008]

The optical encoder according to the present invention is configured as described above, so that the following effects can be obtained. That is, since the light receiving element, the analog signal processing circuit, and the digital signal processing circuit are formed on the same substrate by the ASIC, the light receiving element can be formed into an IC using only one substrate, and the number of parts can be reduced. It is possible to achieve a reduction, a reduction in a component mounting area, a reduction in a manufacturing process, a reduction in cost, and an improvement in reliability.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an optical encoder according to the present invention.

FIG. 2 is a configuration diagram showing a conventional optical encoder.

[Explanation of symbols]

 Reference Signs List 1 light receiving element 1a encoder signal 2 substrate 9 digital signal processing circuit 9A analog signal processing circuit 9a digital encoder signal

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Muneaki Kubota 1879 Oikyu, Iida City, Nagano Prefecture Inside Tamagawa Seiki Co., Ltd. (72) Inventor Kenichi Tamura 1879, Okyu, Iida City, Nagano Prefecture Tamagawa Seiki Co., Ltd. Term (reference) 2F003 AA21 AC02 AD04 5J022 DA02 DB01 DC04 DD04

Claims (1)

[Claims] An encoder signal output from a light receiving element (1)
(1a), in an optical encoder that is output as a digital encoder signal (9a) through an analog signal processing circuit (9A) and a digital signal processing circuit (9), the light receiving element (1), an analog signal processing circuit An optical encoder characterized in that (9A) and the digital signal processing circuit (9) are formed on the same substrate (2) and configured as an application-specific IC.