WO2017161905A1

WO2017161905A1 - Optical encoder

Info

Publication number: WO2017161905A1
Application number: PCT/CN2016/106670
Authority: WO
Inventors: 范小斌; 顾建国; 仲晓伟; 毛剑
Original assignee: 海安县申菱电器制造有限公司
Priority date: 2016-03-23
Filing date: 2016-11-21
Publication date: 2017-09-28
Also published as: CN105651320B; CN105651320A

Abstract

Provided is an optical encoder (111). The optical encoder (111) comprises a light source (1), a lens (2), an optical disk (3) with a rotating shaft (32) in the center, a scale (4) provided with a fixed grating, and a light receiving element (7) sequentially arranged inside the optical encoder (111). The body of the optical disk (3) is a rotatable disk and a center through hole (31) is arranged in the center of the disk base of the optical disk (3), and the rotating shaft (32) is through-connected to the optical disk (3) via the through hole (31). A grating transmission area is arranged on the disk base and a rectangular grating channel (33) is arranged in the grating transmission area. The width of the rectangular grating channel (33) decreases in a linear fashion with the rectangular grating channel (33) arranged so that it circles around the disk to meet itself, the width of one end being the grating width, and the width of the other end being as narrow as possible. The present invention removes higher harmonics and achieves high efficiency and accuracy without increasing manufacturing costs.

Description

Optical encoder

Technical field

The present invention relates to the field of encoder technologies, and in particular, to a photoelectric encoder.

Background technique

The photoelectric encoder is a sensor that detects the displacement and angular acceleration of the transmission member, and realizes light-to-electric conversion. It has a wide range of applications, not only for elevators but also for CNC machine tools, radars, ships, etc. The annual demand in China is about 300,000, of which the elevator needs to reach 100,000. At present, there are fewer manufacturers in China. Changchun Optical Instrument Factory, Nanjing Astronomical Instrument Research Center of Chinese Academy of Sciences, etc., among which only Changchun Optical Instrument Factory has industrial production capacity, and other enterprises have relatively small production scale. At present, more than 50% of the photoelectric encoder market uses imported products. Hai'an Shenling Electric Manufacturing Co., Ltd. has obtained the national patented photoelectric encoder, which has originality in the materials, processing technology and overall structure of the parts. It not only fills the domestic blank, but also replaces the import and exports the same ladder. . The product has strong anti-interference ability, reliable performance and low price compared with imported products, so the market competitiveness is strong.

The photoelectric encoder is an integrated product of light, machine and electricity. It is a precision sensor component that uses the principle of photoelectric conversion to detect the displacement, angular velocity and angular acceleration of the transmission. It consists of a shaft system, a circular encoder system, and an optoelectronic system. Generally, the photoelectric encoder component includes a light source, a slit, a moving grating, and a light receiver, and the assembly position between the components is absolutely accurate. As shown in FIG. 1 , the existing photoelectric encoder component is debugged after being shipped from the factory. Not fixed together, the bracket is used to set the light source and the slit, the movable grating surrounds the sleeve, the light receiver is connected with the circuit board, the user assembles the separate parts of the photoelectric encoder, and the light receiver is screwed with the screw fixing column of the bracket. However, the relative position of the assembled product may be incorrect, and the height of the light source, the slit, the moving grating and the light receiver on a line, such as the height between the moving grating and the bracket, and the height between the moving grating and the light receiver, may not be ensured. The position of the moving grating in the center is not accurate and can be used after re-commissioning. For example, the Chinese patent (application number: 200810201951.X) discloses a photoelectric encoder assembly, which comprises a bracket provided with a light source, a slit and a screw fixing column, a moving grating, a light receiver, a circuit board disposed on the light receiver, and a moving grating. The sleeve is disposed at a center, and the light receiver is screwed to the sleeve of the moving grating; the light receiver is screwed to the screw fixing post of the bracket by a screw. The position of the moving grating is determined by a plug plate that is disposed between the moving grating and the light receiver and that is taken out after installation. The photoelectric encoder assembly is fixed to the motor by screws. The photoelectric encoder assembly is radially fixed to the motor shaft by screws. The technical solution mainly solves the problems of convenient installation, fast time, easy operation, low cost and long service life, but it is well known. Simple connection by threaded screws is not very satisfactory. Although the photoelectric encoder assembly and the motor shaft are matched in the installation direction, the actual use effect is not very superior, so there is a problem to be improved.

Chinese Patent (Application No.: 200710005925.5) discloses a photoelectric encoder (incremental encoder or absolute encoder) having a scale relative to a prescribed pattern (incremental pattern or simulated random pattern), which can be relatively displaced The detector has a plurality of photosensitive systems for dividing the detection range of the pattern that should be simultaneously detected at least in the detection direction, and detecting each of the detection areas. This technical solution proposes the use of a plurality of photosensitive systems to enable the measurement of a wide detection range using a simple small optical system and a photosensitive system. However, this technical solution still exists to make the internal optical system increase, and it is easy to be sensitive to dirt on the scale.

Therefore, the existing photoelectric encoder assembly still has the assembly work with the motor, and the ordinary worker is not easy to install or cannot be installed at all, and requires professional and precision equipment to complete, and the time is long and the cost is high. If the general purchaser does not have such conditions, it will bring great inconvenience to the user. It can be seen that the existing photoelectric encoder has a long installation time, is difficult to operate, has high cost, and has insufficient performance to become a technical bottleneck of the photoelectric encoder.

Summary of the invention

In order to overcome the problems of long installation time, difficult operation, high cost and insufficient performance of the photoelectric encoder existing in the prior art, the present invention provides a photoelectric encoder.

The technical solution adopted by the present invention is: a photoelectric encoder, which comprises a light source, a lens, an optical disk centered on a rotating shaft, a scale provided with a fixed grating, and a light receiving element, and the innovation is The optical disk main body is a rotatable disk, and the center of the disk base is provided with a central through hole, and the rotating shaft is connected to the optical disk through the central through hole, and the grating substrate is provided with a grating transmission area. The grating has a rectangular grating track in the transmission region, and the rectangular grating track changes linearly from the width of one end to the width of the other end; one end of the rectangular grating track is connected end to end with the other end, and the width of one end is a grating width, which varies linearly. The width of the other end tends to be infinitely small.

In this regard, the photoelectric encoder further includes an optical imaging system disposed between the scale and the light receiving element, the optical imaging system including an imaging lens and a diaphragm combination, the imaging lens being disposed in front of the aperture assembly.

Based on this, the aperture combination includes a first aperture and a second aperture, a first aperture and a second aperture A movable aperture stop is disposed on the upper surface, and the size and shape of the movable aperture stop are matched with the aperture size; the first aperture and the second aperture are symmetrically disposed on opposite sides of the nip.

On the basis of the above, the first aperture and the second aperture have the same structure. The first aperture and the second aperture have a specific structure: the first aperture and the second aperture both include the aperture body and the driving device, and the driving device is installed on the The aperture body is provided with a light-transmissive hole in the center of the aperture body, and is provided with a movable aperture stop piece coupled thereto, and the movable aperture stop piece realizes shielding or opening or reducing the light-transmitting aperture of the light-transmitting hole.

On the basis of the above, the driving device is a motor provided with an output shaft, and the output shaft of the motor is connected with the movable aperture stop in the aperture body to realize the movement of the aperture stop automatically.

Based on this, a plurality of photosensitive systems are also included, and the plurality of photosensitive systems are arranged side by side with the optical imaging system.

Based on this, the photosensitive system is provided with 3 to 5.

On the basis of the above, the light-receiving element includes a plurality of light-receiving elements and a light-shielding portion disposed on the light-receiving element, the light-receiving elements are evenly arranged in the same direction and used for detecting the brightness of the light. The light shielding portion is used to block the light and control the brightness of the light.

Based on this, the number of the light receiving elements is 5 to 10.

Based on this, the light receiving element is a photodiode.

Compared with the prior art, the beneficial effects of the present invention are as follows:

(1) The photoelectric encoder of the present invention, the optical disk main body is a rotatable disk, and the center of the disk base of the optical disk is provided with a central through hole, and the rotating shaft is connected to the optical disk through the central through hole, thereby facilitating the optical disk Rotating work, the grating substrate is provided with a grating transmission area, and the grating transmission area is provided with a rectangular grating track, and the rectangular grating track changes linearly from the width of one end to the width of the other end; one end of the rectangular grating track is connected end to end with the other end The width of one end is the width of the grating, and the width of the other end which changes linearly tends to be infinitely small. The specific arrangement of the rectangular grating tracks can remove high-order harmonics without increasing the manufacturing cost, thereby achieving high efficiency and high precision.

(2) The photoelectric encoder of the present invention, the photoelectric encoder further comprising an optical imaging system, the optical imaging system being disposed between the scale and the light receiving element, effectively preventing an increase in the volume of the optical system, and improving the miniaturization process of the optical encoder, and The optical imaging system comprises an imaging lens and an aperture combination, and the imaging lens is arranged in front of the aperture assembly, and has a simple structure and convenient installation.

(3) The photoelectric encoder of the present invention, the aperture combination includes a first aperture and a second aperture, the first aperture A movable aperture stop is disposed on the second aperture, and the size and shape of the movable aperture stop are matched with the aperture size; the first aperture and the second aperture are symmetrically fixed on both sides of the gap, thereby effectively increasing the scale. The field of view on the ruler is enlarged, and the figure or shape of the image can be maintained.

(4) The photoelectric encoder of the present invention, the aperture comprises a diaphragm body and a driving device, the driving device is mounted on the aperture body, a light transmission hole is arranged in the center of the aperture body, and a movable aperture stop piece combined with the same is provided The moving aperture stop realizes shielding or opening or reducing the transmission aperture of the light transmission hole, and effectively maintains the image clarity. The driving device is a motor provided with an output shaft, and the output shaft of the motor and the movable aperture stop in the aperture body The connection realizes the movement of the aperture stop automatically, and the degree of automation is improved.

(5) The photoelectric encoder of the present invention further includes a photosensitive system which is arranged side by side with the optical imaging system, preferably has a number of 3 to 5, and the position is arranged reasonably, which can improve the efficiency of signal detection and expand the allowable range of assembly. .

(6) The photoelectric encoder of the present invention, the light-receiving element includes a plurality of light-receiving elements and a light-shielding portion which are disposed on the light-receiving element, the light-receiving elements are evenly arranged in the same direction and used for detecting the brightness of the light, The light shielding portion is used for blocking the light and controlling the brightness of the light, so as to ensure that the light or the pattern does not overlap with each other in the case of staggered arrangement, thereby effectively improving the image quality.

DRAWINGS

1 is a schematic structural view of the internal structure of the photoelectric encoder of the present invention;

2 is a schematic structural view of an optical encoder of the photoelectric encoder of the present invention;

3 is a schematic structural view of a light receiving element of the photoelectric encoder of the present invention;

4 is a schematic view showing the aperture structure of the photoelectric encoder of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The present invention relates to a photoelectric encoder, as shown in FIG. 1. The photoelectric encoder 111 includes a light source 1, a lens 2, an optical disk 3 centered on a rotating shaft, a scale 4 provided with a fixed grating, and a light receiving unit. The main body of the optical disc 3 is a rotatable disc, as shown in FIG. 2: a center through hole 31 is formed in the center of the disc base of the optical disc 3, and the rotating shaft 32 is connected to the optical disc 3 through the central through hole 31. a grating transmission region is disposed on the disk base, and a rectangular grating track 33 is disposed in the grating transmission region, and the rectangular grating track 33 linearly changes from the width of one end to the width of the other end; one end of the rectangular grating track 33 and the other end of the end Connect, The width of one end is the width of the grating, and the width of the other end that varies linearly tends to be infinitely small. The optical disk structure of the embodiment can facilitate the rotation of the optical disk, and the grating substrate is provided with a grating transmission region, and the grating grating region is provided with a rectangular grating track, and the specific arrangement of the rectangular grating track can be used without increasing the manufacturing cost. The high-order harmonics are removed to achieve high efficiency and high precision.

As shown in FIG. 3, the light receiving element of the present embodiment includes a plurality of light receiving elements 71 and a light blocking portion 72. The light blocking portion 72 is disposed on the light receiving element, and the light receiving elements 71 are evenly arranged in the same direction and used for detecting light. The light and shade portion 72 is used to block light and control the light and darkness of the light. Among them, preferably, the number of the light receiving elements 71 is six, and the light receiving element 71 is selected as a photodiode. The structural arrangement and special arrangement of the light-receiving elements can ensure that the light or the pattern does not overlap with each other in the case of staggered arrangement, thereby effectively improving the image quality.

As shown in FIG. 1, the photoelectric encoder 111 further includes an optical imaging system disposed between the scale 4 and the light receiving element 7, the optical imaging system including the imaging lens 5 and the aperture combination 6, and the imaging lens 5 is disposed in the aperture combination 6 front. The invention comprises an optical imaging system, which is arranged between the scale and the light-receiving element, can effectively prevent the increase of the volume of the optical system, and improve the miniaturization process of the optical encoder, and the optical imaging system comprises an imaging lens and an aperture combination, and the imaging The lens is arranged in front of the aperture assembly, and has a simple structure and convenient installation.

As shown in FIGS. 1, 2, and 4, the aperture assembly 6 includes a first aperture 61 and a second aperture 62. The first aperture 61 and the second aperture 62 are each provided with a movable aperture stop 614, and a movable aperture stop 614. Both the size and the shape are matched with the aperture size; the first aperture 61 and the second aperture 62 are symmetrically disposed on both sides of the nip. The structural arrangement of the aperture combination includes a first aperture and a second aperture, which effectively increases the magnification of the field of view on the scale and maintains the pattern or shape of the image.

Specifically, as shown in FIG. 4, the first aperture 61 and the second aperture 62 have the same structure, and the first aperture 61 and the second aperture 62 have a specific structure: the first aperture 61 and the second aperture 62 both include an aperture. The body 611 and the driving device 612 are mounted on the aperture body 611. The aperture body 611 is provided with a light transmission hole 613 at the center thereof, and is provided with a movable aperture stop 614 coupled thereto. The movable aperture stop 614 is realized. The light-transmitting hole shields or opens or reduces the light-transmitting aperture. Specifically, the aperture comprises a diaphragm body and a driving device, and is provided with a movable aperture stop combined with the aperture stop, the movable aperture stop realizes shielding or opening or reducing the transmission aperture of the light transmission hole, effectively maintaining image clarity and driving The device realizes the movement of the aperture stop automatically, and the degree of automation is improved.

Specifically, the driving device 612 is a motor provided with an output shaft 615, and the output shaft of the motor is connected to the movable aperture stop 614 in the aperture body 611 to automatically drive the movement of the aperture stop.

As shown in FIG. 1 , as a preferred embodiment of the present invention, the photoelectric encoder further includes three photosensitive systems 8 , and three photosensitive systems 8 are arranged side by side with the optical imaging system, and the configuration of the photosensitive system can improve signal detection. Efficiency, expanding the allowable range of assembly.

The above description shows and describes a preferred embodiment of the present invention. As described above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be construed as being Combinations, modifications, and environments are possible, and can be modified by the teachings of the above teachings or related art within the scope of the inventive concept described herein. All changes and modifications made by those skilled in the art are intended to be within the scope of the appended claims.

Claims

A photoelectric encoder, the photoelectric encoder (111) internally comprising a light source (1) placed in sequence, a lens (2), an optical disk (3) provided with a rotating shaft at the center, a scale (4) provided with a fixed grating, and The light receiving element (7) is characterized in that: the main body of the optical disk (3) is a rotatable disk, and a center through hole (31) is provided in the center of the disk base of the optical disk (3), and the rotating shaft (32) Through the central through hole (31) and the optical disk (3), the disk substrate is provided with a grating transmission region, the grating transmission region is provided with a rectangular grating track (33), and the rectangular grating track (33) is from one end The width of the rectangle to the other end varies linearly; one end of the rectangular grating track (33) is connected end to end with the other end, the width of one end is the width of the grating, and the width of the other end which changes linearly tends to be infinitely small.
The photoelectric encoder according to claim 1, wherein said photoelectric encoder (111) further comprises an optical imaging system, said optical imaging system being disposed between the scale (4) and the light receiving element (7), The optical imaging system includes an imaging lens (5) and an aperture combination (6), and an imaging lens (5) is disposed in front of the aperture assembly (6).
A photoelectric encoder according to claim 2, wherein said aperture assembly (6) comprises a first aperture (61) and a second aperture (62), a first aperture (61) and a second aperture (62) A movable aperture stop (614) is disposed on the upper surface, and the movable aperture stop (614) is sized and shaped to match the aperture size; the first aperture (61) and the second aperture (62) are respectively symmetrically fixed Set on both sides of the nip.
The photoelectric encoder according to claim 3, wherein the first aperture (61) is identical in structure to the second aperture (62), and the first aperture (61) and the second aperture (62) are specific The structure is: the first aperture (61) and the second aperture (62) both include a diaphragm body (611) and a driving device (612), and the driving device (612) is mounted on the aperture body (611), the aperture body (611) The center is provided with a light transmission hole (613), and is provided with a movable aperture stop (614) coupled thereto, and the movable aperture stop (614) realizes shielding or opening or reduction of the light transmission hole (613). Light aperture.
The photoelectric encoder according to claim 4, wherein said driving device (612) is a motor provided with an output shaft (615), and an output shaft (615) of the motor and a diaphragm body (611) are The moving aperture stop (614) is connected to automatically drive the movement of the aperture stop.
The photoelectric encoder of claim 1 further comprising a plurality of photosensitive systems (8), each of said plurality of photosensitive systems (8) being juxtaposed with the optical imaging system.
The photoelectric encoder according to claim 6, characterized in that the photosensitive system (8) is provided with 3 to 5.
The photoelectric encoder according to claim 1, wherein the light receiving element (7) includes a plurality of light receiving elements (71) and a light blocking portion (72), and the light shielding portion (72) is disposed on the light receiving element ( 71) The light receiving elements (71) are evenly arranged in the same direction and used to detect the brightness of the light, and the light blocking portion (72) is used to block the light and control the brightness of the light.
The photoelectric encoder according to claim 8, wherein the number of the light receiving elements (71) is 5 to 10.
A photoelectric encoder according to claim 8, wherein said light receiving element (71) is a photodiode.