Photoelectric inductor fusion type encoder

Abstract

The invention provides a photoelectric inductor fusion type encoder, which comprises an encoder chip and an encoder coded disc, and is characterized in that the encoder chip comprises a packaging shell, a light source and a receiving wafer, and the light source and the receiving wafer are respectively arranged at two sides in the shell; a light-transmitting sheet for sealing a shell is arranged above the light source and the receiving wafer, an inductance coil which is made of a transparent conductive material and allows light to penetrate through is arranged on the inner side or the outer side of the light-transmitting sheet, and the inductance coil at least comprises a group of exciting coils and a group of receiving coils; the receiving wafer is electrically connected with the inductance coil to acquire an analog signal generated by the inductance coil; the encoder code disc is provided with an optical code channel of a photoelectric encoder, and the front side or the back side of the encoder code disc is provided with a transparent conductive film which forms a conductive rotor equivalent to that in an inductive encoder. The structure is optimized, and fusion of photoelectric detection and inductance detection functions of the encoder is realized.

Description

Technical Field

[0001] This invention relates to the field of encoder technology, and in particular to an optoelectronic and inductive fusion encoder. Background Technology

[0002] Currently, encoders include the following types:

[0003] Photoelectric encoders, inductive encoders, magnetic encoders, and capacitive encoders are commonly used sensors and are widely used in automation, robotics, CNC machine tools, and other fields.

[0004] Photoelectric encoders utilize the photoelectric principle for position detection. Their working principle involves a light source (usually an LED) emitting light, which passes through the transparent and opaque areas on the encoder disk and is ultimately detected by a receiver (such as the photosensitive area of ​​a photodiode). Photoelectric encoders are mainly divided into incremental and absolute types.

[0005] Incremental encoders: These encoders generate a series of pulse signals to represent changes in rotation angle or position.

[0006] Absolute encoders: provide a unique digital code for each position, ensuring accurate location even after a power outage.

[0007] Inductive encoders primarily operate on the principle of electromagnetic induction. Internally, they consist of a coil and a metal encoder disk. Different shapes and positions of the encoder disk alter the inductance of the coil, thereby generating corresponding electrical signals. Inductive encoders are characterized by their resistance to harsh environments and strong anti-interference capabilities.

[0008] Magnetic encoders detect position by utilizing changes in magnetic fields. They typically contain a magnetic encoder disk and one or more Hall effect sensors. The Hall effect sensors detect changes in the magnetic field at different positions on the encoder disk, thereby generating corresponding electrical signals. Magnetic encoders are also classified into incremental and absolute types.

[0009] Capacitive encoders detect position by utilizing changes in capacitance. They work by altering the capacitance value through changes in the distance and relative position between two electrodes, thus detecting position. Capacitive encoders are highly sensitive and suitable for high-precision applications.

[0010] Different encoders require different system architectures and encoder chips to support the overall solution. Each encoder has its own advantages and disadvantages. For example, photoelectric encoders have the highest accuracy but are less resistant to dirt. Magnetic encoders are inexpensive but lack accuracy and require a permanent magnet structure in the system. Inductive encoders have a simple structure and offer a moderate price and accuracy, etc.

[0011] Optical encoders are widely used in servo systems, elevator systems, aerospace, and many other fields due to their high precision. Typically, the core component of an optical encoder, the encoder chip, contains two or more "code tracks," such as incremental and zero-point code tracks, incremental and reference code tracks, or vernier multi-track tracks. Optical encoder chips with multiple code tracks occupy a larger chip area, increasing the overall chip size and thus the encoder system size. They also make the optical design of the optical encoder chip more complex, especially for reflective optical encoders.

[0012] In addition, in some safety-related applications, such as automotive applications, encoder systems need to be designed with redundancy to ensure functional safety. In the event of failure of one system, the other system can still operate normally. It is difficult for a single encoder chip to achieve the design requirements of a "dual redundancy" system.

[0013] Therefore, it is necessary to provide an optoelectronic and inductive fusion encoder to effectively solve the above problems. Summary of the Invention

[0014] This invention provides an optoelectronic and inductive fusion encoder, which optimizes the structure and integrates the optoelectronic detection and inductive detection functions of the encoder, simplifies the structure of the encoder code disk, or achieves redundancy in encoder position detection.

[0015] This invention provides an optoelectronic-inductive fusion encoder, including an encoder chip and an encoder code disk.

[0016] The encoder chip includes a package housing, a light source, and a receiving wafer. The light source and the receiving wafer are respectively disposed on opposite sides inside the housing. A light-transmitting sheet is disposed above the light source and the receiving wafer to enclose the housing. An inductor coil formed of a transparent conductive material that allows light to pass through is disposed on the inner or outer side of the light-transmitting sheet. The inductor coil includes at least one set of excitation coils and one set of receiving coils. The receiving wafer is electrically connected to the inductor coils to collect the analog signals generated by the inductor coils.

[0017] The encoder code disk is provided with the optical code track of the photoelectric encoder. At the same time, a transparent conductive film is provided on the front or back of the encoder code disk, and the transparent conductive film forms a conductive rotor equivalent to that in an inductive encoder.

[0018] In use, the encoder code disk is mounted on the rotating shaft, and the encoder chip is positioned directly opposite the encoder code disk. Light emitted by the light source passes through the inductor coil and the light-transmitting sheet, and after being reflected by the encoder code disk, it illuminates the photosensitive area of ​​the receiving wafer, which receives the optical signal. Simultaneously, the excitation coil emits an electromagnetic induction signal, which, after being disturbed by the conductive rotor on the encoder code disk, is collected by the receiving coil. The receiving wafer combines the optical signal and the electromagnetic induction signal to output an electrical signal indicating the position of the encoder code disk.

[0019] Preferably, the inductor coil is deposited on the surface of the light-transmitting sheet by thin film deposition; the conductive rotor is made of a transparent conductive material and is deposited on the encoder disk by thin film deposition.

[0020] Preferably, the transparent conductive material is ITO or Al:ZnO.

[0021] Preferably, the inductor coil has at least one layer; the conductive rotor has at least one layer.

[0022] Preferably, the excitation coil is a set, and the receiving coil is a set of multiple sets, with the multiple sets of receiving coils evenly distributed at the center of the excitation coil.

[0023] Preferably, the receiving coils are in sets of 2 or 4.

[0024] Preferably, the light source includes an LED chip, and the photosensitive area of ​​the receiving wafer is disposed on the top surface of the receiving wafer.

[0025] Preferably, the code track includes an incremental code track, and the receiving wafer outputs an incremental signal representing the change in the encoder code disk position based on the received optical signal; simultaneously, the receiving wafer outputs a zero-point signal representing the zero-point position of the encoder code disk based on the electromagnetic induction signal of the receiving coil, and outputs an electrical signal representing the position of the encoder code disk based on the incremental signal and the zero-point signal.

[0026] Preferably, the code track includes an incremental code track and an absolute code track. The receiving wafer outputs a first encoding signal representing the position of the encoder code disk based on the received optical signal, and outputs a first electrical signal representing the position based on the first encoding signal. Simultaneously, the receiving wafer outputs a second encoding signal representing the position of the encoder code disk based on the electromagnetic induction signal collected by the receiving coil, and outputs a second electrical signal representing the position based on the second encoding signal.

[0027] Preferably, the material of the light-transmitting sheet is glass, transparent resin, or quartz.

[0028] Compared with the prior art, the technical solution of the embodiments of the present invention has the following beneficial effects:

[0029] This invention provides a photoelectric and inductive fusion encoder, comprising an encoder chip and an encoder code disk. The encoder chip includes a package housing, a light source, and a receiving wafer, with the light source and receiving wafer respectively disposed on opposite sides within the housing. A light-transmitting sheet enclosed by the housing is disposed above the light source and receiving wafer. An inductor coil formed of a transparent conductive material that allows light to pass through is disposed on the inner or outer side of the light-transmitting sheet. The inductor coil includes at least one set of excitation coils and one set of receiving coils. The receiving wafer is electrically connected to the inductor coils to collect the analog signals generated by the inductor coils. The encoder code disk is provided with the optical code track of the photoelectric encoder. A transparent conductive film is disposed on the front or back of the encoder code disk, forming a conductive rotor equivalent to that in an inductive encoder. The transparent inductor coils and conductive rotor do not affect the optical receiving capability of the photoelectric encoder chip, and integrate controllable inductor coils and conductive rotors, enabling the encoder to simultaneously obtain the analog front-end signal acquisition capability of both a photoelectric encoder and an inductive encoder. This achieves the fusion of photoelectric detection and inductive detection functions of the encoder, simplifying the structure of the photoelectric encoder code disk or achieving redundancy in encoder position detection. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention, but not all embodiments. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A schematic diagram of an optoelectronic-inductive fusion encoder provided for one embodiment of the present invention;

[0032] Figure 2 A schematic diagram of an encoder chip provided for one embodiment of the present invention;

[0033] Figure 3 A schematic diagram of the use of an optoelectronic-inductive fusion encoder is provided for one embodiment of the present invention;

[0034] Figure 4 A schematic diagram of an optoelectronic-inductive fusion encoder provided for another embodiment of the present invention;

[0035] Figure 5 A schematic diagram of an inductor coil provided for one embodiment of the present invention;

[0036] Figure 6 A schematic diagram of an inductor coil provided for another embodiment of the present invention.

[0037] In the picture:

[0038] 1. Encoder chip; 2. Encoder code disk;

[0039] 11. Encapsulation housing; 12. Light source; 13. Receiving wafer; 14. Transmitting sheet; 15. Inductor coil; 151. Receiving coil; 152. Excitation coil;

[0040] 21. Code track; 211. Incremental code track; 212. Absolute code track; 22. Conductive rotor. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments.

[0043] Based on the problems existing in the prior art, this invention provides a photoelectric and inductive fusion encoder, which optimizes the structure, integrates the photoelectric detection and inductive detection functions of the encoder, simplifies the structure of the photoelectric encoder code disk, or achieves redundancy in encoder position detection.

[0044] Figure 1 A schematic diagram of an optoelectronic-inductive fusion encoder provided for one embodiment of the present invention; Figure 2 A schematic diagram of an encoder chip provided for one embodiment of the present invention; Figure 3 A schematic diagram of the use of an optoelectronic-inductive fusion encoder is provided for one embodiment of the present invention; Figure 4 A schematic diagram of an optoelectronic-inductive fusion encoder provided for another embodiment of the present invention; Figure 5 A schematic diagram of an inductor coil or a transparent excitation conductive film provided for one embodiment of the present invention; Figure 6 A schematic diagram of an inductor coil or a transparent excitation conductive film provided for another embodiment of the present invention.

[0045] Now see Figures 1 to 6 This invention provides an optoelectronic-inductive fusion encoder, including an encoder chip 1 and an encoder code disk 2.

[0046] The encoder chip 1 includes a package housing 11, a light source 12, and a receiving wafer 13. The light source 12 and the receiving wafer 13 are respectively disposed on both sides inside the package housing 11. A light-transmitting sheet 14 that encloses the package housing 11 is disposed above the light source 12 and the receiving wafer 13. An inductor coil 15 formed of a transparent conductive material that allows light to pass through is disposed on the inner or outer side of the light-transmitting sheet 14. The inductor coil 15 includes at least one set of excitation coils 152 and one set of receiving coils 151. The receiving wafer 13 is electrically connected to the inductor coil 15 to collect the analog signal generated by the inductor coil 15.

[0047] The encoder code disk 2 is provided with the optical code track 21 of the photoelectric encoder; at the same time, a transparent conductive film is provided on the front or back of the encoder code disk 2, and the transparent conductive film forms a conductive rotor 22 equivalent to that in an inductive encoder.

[0048] In use, the encoder code disk 2 is mounted on the rotating shaft, and the encoder chip 1 is positioned directly opposite the encoder code disk 2. The light emitted by the light source 12 passes through the inductor coil 15 and the light-transmitting sheet 14 and is reflected by the encoder code disk 2 to illuminate the photosensitive area of ​​the receiving wafer 13, where the receiving wafer 13 receives the light signal. At the same time, the excitation coil 152 emits an electromagnetic induction signal, which is disturbed by the conductive rotor 22 on the encoder code disk 2 and collected by the receiving coil 151. The receiving wafer 13 combines the light signal and the electromagnetic induction signal and outputs an electrical signal indicating the position of the encoder code disk 2.

[0049] The inductor coil 15 and the conductive rotor 22 do not affect the optical receiving capability of the photoelectric encoder chip, and integrate controllable inductor coil 15 and conductive rotor 22. This allows the encoder to simultaneously acquire the analog front-end signal acquisition capability of both photoelectric encoders and inductive encoders, achieving the fusion of photoelectric detection and inductive detection functions. This simplifies the structure of the photoelectric encoder code disk or provides redundancy for encoder position detection. It can be applied in both transmissive and reflective photoelectric encoders.

[0050] In some embodiments, the inductor coil 15 is deposited on the surface of the light-transmitting sheet 14 by thin film deposition; the conductive rotor 22 is made of a transparent conductive material and is deposited on the encoder code disk 2 by thin film deposition.

[0051] In some embodiments, the transparent conductive material is ITO (indium tin oxide) or Al:ZnO (aluminum-doped zinc oxide), which transmits light while possessing electrical properties similar to those of metals.

[0052] In some embodiments, the inductor coil 15 is at least one layer, and may be one or more layers; the conductive rotor 22 is at least one layer, and may be one or more layers.

[0053] Please see Figure 5 and Figure 6 In some embodiments, the excitation coil 152 is a group, and the receiving coil 151 is a group, with the multiple groups of receiving coils 151 evenly distributed at the center of the excitation coil 152.

[0054] Please see Figure 5 and Figure 6 The receiving coil 151 has 2 or 4 groups.

[0055] In some embodiments, the light source 12 includes an LED chip disposed on the top of the light source 12, and the photosensitive area of ​​the receiving wafer 13 is disposed on the top surface of the receiving wafer 13.

[0056] In some embodiments, the light-transmitting sheet 14 is made of glass, transparent resin, or quartz.

[0057] Please see Figures 1-3 In some embodiments, the code track 21 includes an incremental code track 211. The receiving wafer 13 outputs an incremental signal representing the change in position of the encoder code disk 2 based on the received optical signal. Simultaneously, the receiving wafer 13 outputs a zero-point signal representing the zero-point position of the encoder code disk 2 based on the electromagnetic induction signal collected by the receiving coil 151, and outputs an electrical signal representing the position of the encoder code disk 2 based on the incremental signal and the zero-point signal. The zero-point code track (usually the Z signal code track) of the existing reflective incremental photoelectric encoder chip can be deleted, and an inductor coil 15 and a conductive rotor 22 can be set. The zero-point signal representing the zero-point position of the encoder code disk 2 is output through the electromagnetic induction signal collected by the receiving coil 151. Therefore, the high-precision incremental code track function of the reflective incremental photoelectric encoder chip remains unchanged. Through the inductor coil 15 and the conductive rotor 22, the accurate generation of the zero-point analog signal is realized, simplifying the structure of the photoelectric encoder code disk.

[0058] Please see Figures 2-4In some embodiments, the code track 21 includes an incremental code track 211 and an absolute code track 212. The receiving wafer 13 outputs a first incremental signal representing the change in position of the encoder code disk 2 and a first encoded signal representing the position of the encoder code disk 2 based on the received optical signal, and outputs a first electrical signal representing the position based on the first encoded signal. Simultaneously, the receiving wafer 13 outputs a second encoded signal representing the position of the encoder code disk 2 based on the electromagnetic induction signal of the collected receiving coil 151, and outputs a second electrical signal representing the position based on the second encoded signal. An inductor coil 15 can be set on an existing reflective photoelectric encoder chip, and a conductive rotor 22 can be set on the encoder code disk 2. The high-precision code track function of the existing reflective photoelectric encoder remains unchanged. At the same time, through the inductor coil 15 and the conductive rotor 22, the second electrical signal of the encoder code disk 2 position is accurately generated by inductive measurement, realizing the redundancy design of the inductive encoder output. The dual encoder output design is realized without changing the system size. The encoder photoelectric detection and inductive detection functions are integrated to achieve redundancy of encoder position detection.

[0059] In summary, the present invention provides an optoelectronic inductive fusion encoder, wherein the encoder chip 1 includes a package shell 11, a light source 12, and a receiving wafer 13. The light source 12 and the receiving wafer 13 are respectively disposed on both sides inside the package shell 11. A light-transmitting sheet 14 enclosing the package shell 11 is disposed above the light source 12 and the receiving wafer 13. An inductor coil 15 formed of a transparent conductive material that allows light to pass through is disposed on the inner or outer side of the light-transmitting sheet 14. The inductor coil 15 includes at least one set of excitation coils 152 and one set of receiving coils 151. The receiving wafer 13 is electrically connected to the inductor coil 15 to collect the analog signal generated by the inductor coil 15. The encoder code disk 2 is provided with the optical code track 21 of the photoelectric encoder; at the same time, a transparent conductive film is provided on the front or back of the encoder code disk 2, and the transparent conductive film forms a conductive rotor 22 equivalent to that in an inductive encoder; the inductor coil 15 and the conductive rotor 22 do not affect the optical receiving capability of the photoelectric encoder chip, and integrate controllable inductor coil 15 and conductive rotor 22, so that the encoder simultaneously obtains the analog front-end signal acquisition capability of the photoelectric encoder and the analog front-end signal acquisition capability of the inductive encoder, realizes the fusion of the encoder photoelectric detection and inductive detection functions, simplifies the structure of the photoelectric encoder code disk or realizes the redundancy of encoder position detection.

[0060] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A photoelectric inductive fusion encoder, characterized in that: Including encoder chip and encoder disc, The encoder chip includes a packaging shell, a light source and a receiving wafer, wherein the light source and the receiving wafer are respectively arranged on both sides of the shell; a light-transmitting sheet that closes the shell is arranged above the light source and the receiving wafer, and an inductor coil formed of a transparent conductive material that allows light to pass through is arranged on the inner side or the outer side of the light-transmitting sheet, wherein the inductor coil includes at least one group of excitation coils and one group of receiving coils, and the receiving wafer is electrically connected to the inductor coil to collect the analog signal generated by the inductor coil; The encoder code disc is provided with an optical code track of a photoelectric encoder, and a transparent conductive film is provided on the front or back side of the encoder code disc, and the transparent conductive film forms a conductive rotor equivalent to that in an inductive encoder; When in use, the encoder code disc is installed on the rotating shaft, and the encoder chip is arranged opposite to the encoder code disc. The light emitted by the light source passes through the inductor coil and the light-transmitting sheet, is reflected by the encoder code disc, and then irradiates the photosensitive area of ​​the receiving wafer, and the receiving wafer receives the light signal; at the same time, the excitation coil emits an electromagnetic induction signal, which is disturbed by the conductive rotor on the encoder code disc, and the electromagnetic induction signal is collected by the receiving coil; the receiving wafer fuses the light signal and the electromagnetic induction signal, and outputs an electrical signal indicating the position of the encoder code disc.

2. The photoelectric inductive fusion encoder according to claim 1, characterized in that: The inductor coil is deposited on the surface of the light-transmitting sheet by thin film deposition; the conductive rotor is made of a transparent conductive material, and the conductive rotor is deposited on the encoder code disc by thin film deposition.

3. The photoelectric inductive fusion encoder according to claim 2, characterized in that: The transparent conductive material is ITO or Al:ZnO.

4. The photoelectric inductive fusion encoder according to claim 1, characterized in that: The inductor coil is at least one layer; the conductive rotor is at least one layer.

5. The photoelectric inductive fusion encoder according to claim 1, characterized in that: The excitation coils are grouped into one group, the receiving coils are grouped into multiple groups, and the multiple groups of receiving coils are evenly distributed at the center of the excitation coils.

6. The photoelectric inductive fusion encoder according to claim 5, characterized in that: The receiving coils are in 2 groups or 4 groups.

7. The photoelectric inductive fusion encoder according to claim 1, characterized in that: The light source includes an LED chip, and the photosensitive area of ​​the receiving wafer is arranged on the top surface of the receiving wafer.

8. The photoelectric inductive fusion encoder according to claim 1, characterized in that: The code channel includes an incremental code channel, and the receiving wafer outputs an incremental signal representing the change in the position of the encoder code disk based on the received optical signal; at the same time, the receiving wafer outputs a zero-point signal representing the zero-point position of the encoder code disk based on the collected electromagnetic induction signal of the receiving coil, and outputs an electrical signal representing the position of the encoder code disk based on the incremental signal and the zero-point signal.

9. The photoelectric inductive fusion encoder according to claim 1, characterized in that: The code channel includes an incremental code channel and an absolute value code channel. The receiving wafer outputs a first coded signal representing the position of the encoder code disk according to the received optical signal, and outputs a first electrical signal representing the position according to the first coded signal. At the same time, the receiving wafer outputs a second coded signal representing the position of the encoder code disk according to the collected electromagnetic induction signal of the receiving coil, and outputs a second electrical signal representing the position according to the second coded signal.

10. The photoelectric-inductive fusion encoder according to claim 1, characterized in that: The material of the light-transmitting sheet is glass, transparent resin or quartz.

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