Photoelectric encoder based on local surface plasmon effect

Abstract

The invention discloses a photoelectric encoder based on a local surface plasmon effect, which comprises a shell, a mounting frame, a lamp holder, a coded disc I, a coded disc II, a photoelectric conversion device, a rotating wheel and a rotating shaft, and is characterized in that the rear end of the rotating shaft is connected with the output end of a measured object, and the other end of the rotating shaft extends into the shell; a lamp holder, a first code disc, a second code disc, a photoelectric conversion device and a rotating wheel are sequentially arranged in the shell at intervals in the direction from the front end to the rear end of the rotating shaft, lamp beads are installed on the lamp holder, light-transmitting grooves are distributed in the first code disc and the second code disc in the radial direction, the first code disc and the second code disc are fixed to the rotating shaft, and the light-transmitting grooves of the first code disc and the light-transmitting grooves of the second code disc are arranged in a staggered mode. The photoelectric conversion device is installed on the inner wall of the shell through a fixing frame, the face, facing the second code disc, of the photoelectric conversion device is a light receiving area, gold nanoparticles are distributed on the light receiving area, and the photoelectric conversion device is connected with the resistor and the current display device to form a detection loop. The rotating shaft penetrates through the lamp holder and the photoelectric conversion device.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric encoders, and in particular to a photoelectric encoder based on localized surface plasmon effect. Background Art

[0002] The photoelectric encoder is mainly composed of a grating disk and a photoelectric detection device. In the servo system, the grating disk is coaxial with the motor so that the rotation of the motor drives the rotation of the grating disk, and then a number of pulse signals are output through the photoelectric detection device. The current motor speed can be calculated based on the number of pulses per second of the signal.

[0003] Usually, the photoelectric detection device of the photoelectric encoder is a code disk that outputs two optical codes with a phase difference of 90 degrees, converts the displacement into an electrical signal, and then converts the electrical signal into a counting pulse. It can usually be divided into two types: non-contact and contact. Among them, the contact code disk uses a brush to contact the electrical area or the insulating area, and the non-contact type uses a non-photosensitive element to receive the light-transmitting area or the opaque area to distinguish the current position state. The absolute encoder uses several concentric code channels, and uses the different positions of the light source and the photosensitive element on both sides of the code disk to cause the photosensitive element to receive light changes to distinguish the current code disk position. The main working principle of the hybrid absolute encoder is the same as the first two encoders, the only difference is the output quantity.

[0004] During the use of encoders, they are often restricted by the use conditions of photosensitive elements or optical code disks, which makes it impossible to directly install them in harsh environments such as high temperature and high vibration. At the same time, there are many structures installed in the encoder, which makes the installation complicated. The encoder cannot be used in high vibration environments, and there are also significant problems such as high maintenance costs. Therefore, it is urgent to propose solutions to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a photoelectric encoder based on the localized surface plasmon effect, which can effectively improve the working temperature range of the photoelectric encoder, improve the anti-vibration ability of the photoelectric encoder, and improve the working efficiency of the encoder in various harsh environments.

[0006] In order to achieve the above tasks, the present invention adopts the following technical solutions:

[0007] A photoelectric encoder based on localized surface plasmon effect, comprising a housing, a mounting frame, a lamp frame, a first code disc, a second code disc, a photoelectric conversion device, a rotating wheel and a rotating shaft, wherein:

[0008] The shell is a closed cavity, the rear end of the rotating shaft is connected to the output end of the object to be measured, and the other end extends into the interior of the shell; on the rotating shaft inside the shell, the lamp holder, code disc 1, code disc 2, photoelectric conversion device and rotating wheel are arranged in sequence from the front end to the rear end of the rotating shaft, wherein the lamp holder is fixed to the inner wall of the shell through a mounting frame, and lamp beads are installed on the lamp holder; code disc 1 and code disc 2 are both radially distributed with light-transmitting grooves, code disc 1 and code disc 2 are fixed on the rotating shaft and the light-transmitting grooves of the two are staggered; the photoelectric conversion device is installed on the inner wall of the shell through a fixing frame, the side of the photoelectric conversion device facing code disc 2 is a light-receiving area, gold nanoparticles are distributed on the light-receiving area, the photoelectric conversion device is connected to the resistor and the current display device to form a detection circuit; the rotating shaft passes through the lamp holder and the photoelectric conversion device.

[0009] Furthermore, the wavelength range of the emitted light from the lamp beads installed on the lamp holder is between 460nm and 720nm.

[0010] Furthermore, the code disc 1 and the code disc 2 are both disc structures, and the light-transmitting grooves are symmetrically distributed on both sides of the diameter of the code disc 1 and the code disc 2; wherein the width of the light-transmitting groove on the code disc 1 is greater than the width of the light-transmitting groove on the code disc 2.

[0011] Furthermore, there is an angle of 30° to 60° between the light-transmitting groove on the first code disc and the light-transmitting groove on the second code disc.

[0012] Furthermore, the photoelectric conversion device comprises a silicon dioxide semiconductor with a disc-shaped structure, and the upper surface of the silicon dioxide semiconductor is a light-receiving area on which gold nanoparticles are distributed.

[0013] Furthermore, the processing technology of the photoelectric conversion device is:

[0014] S1, performing reactive ion etching on the upper surface of the silicon dioxide semiconductor, thereby forming spherical holes on the upper surface;

[0015] S2, coating the upper surface of the silicon dioxide semiconductor with a P4VP ethylene polymer;

[0016] S3, coating a layer of potassium chloroaurate solution on the upper surface coated with the P4VP ethylene polymer; in this process, the vinyl groups in the P4VP ethylene polymer use electrostatic adsorption to adsorb the gold nanoparticles 9 in the potassium chloroaurate solution onto the upper surface of the silicon dioxide semiconductor and in the spherical pores;

[0017] S4, washing away the P4VP ethylene polymer on the upper surface of the silicon dioxide semiconductor to form a light receiving area.

[0018] Furthermore, the spherical hole is 5-10 nm, the etching time is 5-10 s, and the depth of the spherical hole is 4-8 nm.

[0019] Furthermore, the diameter of the gold nanoparticles is 5-10 nm.

[0020] Furthermore, the mass concentration of the potassium chloroaurate solution is 15%.

[0021] Furthermore, the photoelectric conversion device is connected to the resistor and the current display device through a wire; after the metal nanoparticles on the photoelectric conversion device receive light radiation, a current is generated in the detection circuit, and the intensity of the current is affected by the light intensity;

[0022] According to the results of the advance test and calibration, the relationship between the current intensity and the rotation angle of the shaft can be obtained, and thus the precise rotation angle of the object under test can be obtained through the reading of the current display device.

[0023] Compared with the prior art, the present invention has the following technical features:

[0024] 1. The photoelectric conversion device designed in the present invention based on the localized surface plasmon effect LSPR can greatly improve the working temperature range of the photoelectric encoder. Since the photoelectric conversion device uses gold nanoparticles, which have high thermal and chemical stability, it can ensure that the photoelectric encoder can be used in higher temperatures and harsher environments.

[0025] 2. The photoelectric conversion device in the present invention has a physical property of metal nanoparticles because its photoelectric response process is inherent to the metal nanoparticles. Therefore, this property will not change with changes in the external environment. At the same time, when the incident light shines on the gold nanoparticles, the photocurrent generated on the surface responds immediately without any delay, thus ensuring the real-time and accuracy of the photoelectric encoder signal to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 is a schematic structural diagram of a photoelectric conversion device;

[0028] Figure 3 It is a structural schematic diagram of the code disk 1;

[0029] Figure 4 This is a schematic diagram of the structure of the code disk 2.

[0030] Explanation of the numbers in the figure: 1 mounting frame, 2 lamp frame, 3 code disc one, 4 code disc two, 5 rotating wheel, 6 photoelectric conversion device, 7 rotating shaft, 8 shell, 9 gold nanoparticles, 10 current display device, 11 resistor, 12 wire. DETAILED DESCRIPTION

[0031] See attached Figure 1The present invention provides a photoelectric encoder based on the localized surface plasmon effect, comprising a housing 8, a mounting frame 1, a lamp frame 2, a code disc 1 3, a code disc 2 4, a photoelectric conversion device 6, a rotating wheel 5 and a rotating shaft 7, wherein:

[0032] The shell 8 is a closed cavity, the rear end of the rotating shaft 7 is connected to the output end of the object to be measured, and the other end extends into the interior of the shell 8; on the rotating shaft 7 inside the shell 8, the lamp holder 2, the code disc 1 3, the code disc 2 4, the photoelectric conversion device 6 and the rotating wheel 5 are arranged in sequence from the front end to the rear end of the rotating shaft 7, wherein the lamp holder 2 is fixed to the inner wall of the shell 8 by the mounting frame 1, and lamp beads are installed on the lamp holder 2; the code disc 1 3 and the code disc 2 4 are radially distributed with light-transmitting grooves, the code disc 1 3 and the code disc 2 4 are fixed on the rotating shaft 7 and the light-transmitting grooves of the two are staggered; the photoelectric conversion device 6 is installed on the inner wall of the shell 8 by a fixing frame, the side of the photoelectric conversion device 6 facing the code disc 2 4 is a light receiving area, and gold nanoparticles 9 are distributed on the light receiving area, and the photoelectric conversion device 6 is connected to the resistor 11 and the current display device 10 to form a detection circuit; the rotating shaft 7 passes through the lamp holder 2 and the photoelectric conversion device 6.

[0033] In the present invention, the wavelength range of the light emitted by the lamp beads installed on the lamp holder 2 is between 460nm and 720nm. The light within this wavelength range is within the strong absorption range of the gold nanoparticles 9 on the photoelectric conversion device 6, which is conducive to the accurate response of the encoder.

[0034] See also Figure 3 and Figure 4 In this scheme, the code disc 1 3 and the code disc 2 4 are both disc structures, and strip-shaped light-transmitting grooves are distributed radially on the code disc 1 3 and the code disc 2 4, and the light-transmitting grooves are symmetrically distributed on both sides of the diameter of the code disc 1 3 and the code disc 2 4; during actual processing, the light-transmitting grooves should be made to cover the surface of the code disc 1 3 and the code disc 2 4 as much as possible.

[0035] The width of the light-transmitting groove on the code disc 1 3 is greater than the width of the light-transmitting groove on the code disc 2 4; in one embodiment of the present invention, the widths are 0.2 cm and 0.1 cm respectively; the code disc 1 3 and the code disc 2 4 are fixed on the rotating shaft 7 and rotate with the rotating shaft 7; when installing the code disc 1 3 and the code disc 2 4, ensure that the light-transmitting groove on the code disc 1 3 and the light-transmitting groove on the code disc 2 4 are staggered, that is, there is an angle of 30° to 60° between the two; then under the illumination of the lamp beads, as the code disc 1 3 and the code disc 2 4 continue to rotate, the light intensity that passes through the light-transmitting grooves on the code disc 1 3 and the code disc 2 4 and reaches the light-receiving area on the photoelectric conversion device 6 is also constantly changing, thereby causing the current intensity in the detection circuit to change.

[0036] The rotating wheel 5 is used to increase the rotation load of the rotating shaft 7, so that the rotating shaft 7 rotates more smoothly.

[0037] See attached Figure 2 The photoelectric conversion device 6 described in this scheme includes a disk-shaped silicon dioxide semiconductor, the upper surface of which is a light-receiving area and is distributed with gold nanoparticles 9; the specific process is as follows:

[0038] S1, the upper surface of the silicon dioxide semiconductor is subjected to reactive ion etching to form spherical holes with an outer diameter of 5-10nm on the upper surface, the etching time is 5-10s, and the depth of the spherical holes is 4-8nm; by processing the spherical holes, the light receiving surface can be increased and the photoelectric conversion efficiency can be improved.

[0039] S2, coating the upper surface of the silicon dioxide semiconductor with P4VP ethylene polymer.

[0040] S3, coating a layer of potassium chloroaurate solution with a mass concentration of 15% on the upper surface coated with the P4VP ethylene polymer; in this process, the vinyl groups in the P4VP ethylene polymer utilize electrostatic adsorption to adsorb gold nanoparticles 9 in the potassium chloroaurate solution onto the upper surface of the silicon dioxide semiconductor and in the spherical pores, and the adsorbed gold nanoparticles can be effectively cross-linked; the diameter of the gold nanoparticles 9 is 5-10nm.

[0041] S4, using distilled water to rinse the P4VP ethylene polymer on the upper surface of the silicon dioxide semiconductor to form the light receiving area.

[0042] In this solution, the processed photoelectric conversion device 6 is connected to the resistor 11 and the current display device 10 (for example, an ammeter) through the wire 12, and the working principle is as follows:

[0043] After receiving light radiation, the metal nanoparticles on the silicon dioxide semiconductor generate hot electrons and hot holes that can be transmitted to the N region and P region of the silicon dioxide semiconductor. After the two ends of the PN junction absorb the hot electrons and hot holes respectively, an electric potential difference will be generated at both ends of the PN junction. Therefore, a current can be generated by connecting the two ends of the PN junction with a wire 12 to form a loop. The intensity of the current is affected by the light intensity.

[0044] According to the results of the advance test and calibration, the relationship between the current intensity and the rotation angle of the shaft 7 can be obtained, thereby the precise rotation angle of the object under test can be obtained through the reading of the current display device 10; by selecting the resistance value of the resistor 11, the current size in the detection circuit can be adjusted for easy measurement.

[0045] When the present invention is in use, the rotating shaft 7 is connected to the output end of the object to be measured, and the object to be measured drives the code disk 1 3 and the code disk 2 4 to rotate through the rotating shaft 7, thereby changing the light intensity irradiated on the light receiving area of ​​the photoelectric conversion device 6, so that the current intensity detected by the current display device 10 changes, and the rotation angle of the object to be measured is obtained according to the pre-calibrated corresponding relationship.

[0046] The present invention utilizes the localized plasma effect on the metal surface to generate a photoelectric response module for photocurrent, which can effectively improve the applicable temperature range of the photoelectric encoder, broaden its scope of application, and greatly reduce the manufacturing difficulty. At the same time, the stability of the metal surface plasma effect is extremely high, which reduces the manufacturing cost and reduces the cumbersome maintenance process.

[0047] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A photoelectric encoder based on localized surface plasmon effect, characterized in that: It comprises a housing (8), a mounting frame (1), a lamp frame (2), a code disc 1 (3), a code disc 2 (4), a photoelectric conversion device (6), a rotating wheel (5) and a rotating shaft (7), wherein: The housing (8) is a closed cavity, the rear end of the rotating shaft (7) is connected to the output end of the object to be measured, and the other end extends into the interior of the housing (8); on the rotating shaft (7) inside the housing (8), the lamp holder (2), the code disc 1 (3), the code disc 2 (4), the photoelectric conversion device (6) and the rotating wheel (5) are arranged in sequence from the front end to the rear end of the rotating shaft (7), wherein the lamp holder (2) is fixed to the inner wall of the housing (8) by means of a mounting frame (1), and a lamp bead is mounted on the lamp holder (2); the code disc 1 (3), the code disc 2 (4) 4) are radially provided with light-transmitting grooves, the first code disc (3) and the second code disc (4) are fixed on the rotating shaft (7) and the light-transmitting grooves of the two are arranged alternately; the photoelectric conversion device (6) is installed on the inner wall of the shell (8) through a fixing frame, the side of the photoelectric conversion device (6) facing the second code disc (4) is a light-receiving area, and gold nanoparticles (9) are distributed on the light-receiving area, the photoelectric conversion device (6) is connected with a resistor (11) and a current display device (10) to form a detection circuit; the rotating shaft (7) passes through the lamp frame (2) and the photoelectric conversion device (6).

2. The photoelectric encoder based on the localized surface plasmon effect according to claim 1, characterized in that: The wavelength range of the emitted light from the lamp beads installed on the lamp frame (2) is between 460nm and 720nm.

3. The photoelectric encoder based on the localized surface plasmon effect according to claim 1, characterized in that: The code disc 1 (3) and the code disc 2 (4) are both disc structures, and the light-transmitting grooves are symmetrically distributed on both sides of the diameter of the code disc 1 (3) and the code disc 2 (4); wherein the width of the light-transmitting groove on the code disc 1 (3) is greater than the width of the light-transmitting groove on the code disc 2 (4).

4. The photoelectric encoder based on the localized surface plasmon effect according to claim 1, characterized in that: There is an angle of 30° to 60° between the light-transmitting groove on the first code disc (3) and the light-transmitting groove on the second code disc (4).

5. The photoelectric encoder based on the localized surface plasmon effect according to claim 1, characterized in that: The photoelectric conversion device (6) comprises a silicon dioxide semiconductor with a disc-shaped structure, and the upper surface of the silicon dioxide semiconductor is a light receiving area on which gold nanoparticles (9) are distributed.

6. The photoelectric encoder based on the localized surface plasmon effect according to claim 1, characterized in that: The processing technology of the photoelectric conversion device (6) is as follows: S1, performing reactive ion etching on the upper surface of the silicon dioxide semiconductor, thereby forming spherical holes on the upper surface; S2, coating the upper surface of the silicon dioxide semiconductor with a P4VP ethylene polymer; S3, coating a layer of potassium chloroaurate solution on the upper surface coated with the P4VP ethylene polymer; in this process, the vinyl groups in the P4VP ethylene polymer use electrostatic adsorption to adsorb the gold nanoparticles 9 in the potassium chloroaurate solution onto the upper surface of the silicon dioxide semiconductor and in the spherical pores; S4, washing away the P4VP ethylene polymer on the upper surface of the silicon dioxide semiconductor to form a light receiving area.

7. The photoelectric encoder based on the localized surface plasmon effect according to claim 1, characterized in that: The spherical hole is 5-10 nm, the etching time is 5-10 s, and the depth of the spherical hole is 4-8 nm.

8. The photoelectric encoder based on the localized surface plasmon effect according to claim 1, characterized in that: The diameter of the gold nanoparticles (9) is 5-10 nm.

9. The photoelectric encoder based on the localized surface plasmon effect according to claim 1, characterized in that: The mass concentration of the potassium chloroaurate solution is 15%.

10. The photoelectric encoder based on the localized surface plasmon effect according to claim 1, characterized in that: The photoelectric conversion device (6) is connected to a resistor (11) and a current display device (10) via a wire (12); after the metal nanoparticles on the photoelectric conversion device (6) receive light radiation, a current is generated in a detection circuit, and the intensity of the current is affected by the light intensity; According to the results of the pre-test calibration, the relationship between the current intensity and the rotation angle of the rotating shaft (7) can be obtained, and thus the precise rotation angle of the object to be measured can be obtained through the reading of the current display device (10).

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