WO2021026960A1

WO2021026960A1 - Digital measurement tape, encoding device for digital measurement tape and corresponding measurement method

Info

Publication number: WO2021026960A1
Application number: PCT/CN2019/102099
Authority: WO
Inventors: 胡文亮; 彭圣
Original assignee: 珠海市易迅科技有限公司
Priority date: 2019-08-12
Filing date: 2019-08-23
Publication date: 2021-02-18
Also published as: CN110608757A

Abstract

Provided is an encoding device for digital measurement tape, comprising a coded disc, a roller; wherein the coded disc has a central through hole, a rotation shaft is arranged in the center of the roller and is matched with the central through hole; a metal elastic member is fixedly arranged on the roller; multiple groups of metal contact pieces are arranged on one side surface of the coded disc in a staggered manner along a radial direction of the side surface and protrude out of the side surface, the multiple groups of metal contact pieces do not completely cover one side surface of the coded disc; each group of the multiple groups of metal contact pieces comprises one or more metal contact pieces; the metal elastic member is arranged in a one fourth circle of the roller, and comprises one or more strip-shaped metal elastic contact bodies, which are the same in number with multiple groups of metal contact pieces, are matched with the metal contact pieces and are spaced with each other in a protruding manner.

Description

Digital measuring tape, coding device used for digital measuring tape and corresponding measuring method

Technical field

The invention relates to the field of digital measurement, in particular to a digital measuring tape, an encoding device for the digital measuring tape, and a corresponding measuring method.

Background technique

A tape measure is a tool for measuring length often used in daily life. Because it is soft and can be rolled up, it is also a tape measure. In order to facilitate the measurement and reading, a digital measuring tape has appeared in recent years. Through a certain digital method, the rotation of the code wheel is converted into the length of the measured object and displayed on the LCD screen. However, although some existing digital tape measures are convenient for reading, they have the problem of insufficient measurement accuracy. Such tape measures are not suitable for applications requiring high measurement accuracy. Therefore, it is necessary to design a digital measuring tape that can facilitate reading and improve measurement accuracy to meet the requirements of high measurement accuracy.

The application number is 201611240444.8, a Chinese invention patent entitled "Smart tape measure and its measuring method", discloses a smart tape measure and its measuring method. A counting roller is set at the exit of the tape measure. When the tape measure is pulled out, the roller rotates. The number of laps and the circumference of the roller can be calculated and displayed on the display screen. At the same time, a counting roller is also set in the lower part of the tape measure box to facilitate measuring the length of the concave surface. When the data is confirmed, it will be automatically uploaded to the mobile terminal through the wireless network. After processing on the mobile terminal, it is automatically uploaded to the cloud and saved. However, it requires two counting rollers, and the structure is more complicated.

Summary of the invention

In order to solve the problem of the complicated measurement structure of the digital tape measure in the prior art, the present invention provides a digital tape measure, an encoding device for the digital tape measure, and a corresponding measurement method.

First of all, the present invention proposes an encoding device for digital tape measure, including:

Code disc, said code disc is circular and has a central through hole;

A roller matched with the code wheel, the center of the roller wheel has a rotating shaft matched with the central through hole, so that the roller can be fixed above the code wheel, contact with the code wheel and relative to the code wheel Disk rotation; and

A metal elastic member fixed on the roller;

On one side of the code wheel, a plurality of sets of metal contacts protruding from the side are arranged in a radial direction and staggered along the one side surface, and the multiple sets of metal contacts do not completely cover the code wheel The one side surface; wherein, each of the plurality of sets of metal contacts includes one or more metal contacts;

The metal elastic member is distributed in the 1/4 circle of the roller, and includes the same number as the number of the groups of the plurality of metal contact pieces, and the metal contact pieces are matched with each other and spaced apart from each other. One or more strip-shaped metal elastic contact bodies, so that when the roller rotates relative to the code wheel, it can contact only one metal contact piece in the same group of the multiple sets of metal contact pieces at the same time In addition, at different moments in the same period, the contact relationship between the metal elastic contact body in the metal elastic member and the multiple sets of metal contacts is unique.

Further, in the above-mentioned encoding device proposed by the present invention, in the multiple groups of metal contacts, the radial distance from the center of each of the metal contacts belonging to the same group to the center of the code wheel is equal, and belongs to different The radial distances from the centers of any two metal contact pieces in the group to the center of the code wheel are not equal.

Furthermore, in the above-mentioned encoding device proposed by the present invention, each of the metal contacts is a circular ring segment with a certain radial width, which has a first arc surface and a second arc surface in the radial direction, wherein, The distance from the first arc surface to the center of the code wheel is smaller than the distance from the second arc surface to the center of the circle.

Further, in the above-mentioned encoding device proposed by the present invention, among the multiple groups of metal contacts, each of the metal contacts belonging to the same group is evenly distributed in the circumferential direction of a circle formed at the same radial distance, so that they belong to The center angle formed by the center of two adjacent contact members in the same group and the center of the code wheel is equal.

Further, in the above-mentioned encoding device provided by the present invention, the number of the groups of the plurality of metal contacts is 4 groups.

Further, in the above-mentioned encoding device provided by the present invention, in the first group of metal contacts, the through hole closest to the center of the code disc, and the first arc surface of the first group of metal connection components is at the center of the code disc. The central angle of the composition is 26°; the second group of metal contacts is close to the first group of metal contacts and farther away from the center of the code wheel, and the first arc of the first group of metal contacts is The center angle formed by the center of the code wheel is 30°; the third group of metal contacts is close to the second group of metal contacts and farther away from the center of the code disk, and the first group of metal contacts The central angle formed by the first arc of the piece and the center of the code wheel is 13°; the fourth group of metal contacts is close to the third group of metal contacts and farther away from the center of the code wheel, and The central angle formed by the first arc surface of the fourth group of metal contacts and the center of the code wheel is 6°.

Further, in the aforementioned encoding device provided by the present invention, the diameters of the code wheel and the roller are both φ41, the diameter of the central through hole of the code disk is φ10; the diameter of the rotating shaft of the roller is φ10.6.

Secondly, the present invention provides a digital measuring tape including the encoding device as described above, and further includes a processor, a decoding device, a communication device, and a display device; wherein,

The processor is connected to the encoding device, the decoding device, the communication device and the display device of the digital tape measure, and is used to send control instructions to the above-mentioned device and perform displacement calculation;

The decoding device is connected to the processor and the encoding device, and is used to decode the code generated by the encoding device;

The communication device is connected to the processor, and is used to send the displacement calculated by the processor;

The display device is connected to the processor and is used for displaying the displacement calculated by the processor.

Third, the present invention proposes a method for measuring displacement using the above-mentioned digital tape measure, which includes the following steps:

A. Generated at each detection time point, the metal elastic contact body is respectively the code group formed by the metal contact or not contacting;

B. According to the size of the code disc, the setting mode of the metal contact, and the detection time interval, the corresponding relationship between the angular displacements of the two adjacent codes in the code group is obtained;

C. Determine the amount of displacement according to the above-mentioned correspondence and the number of codes in the received code group.

Finally, the present invention proposes a computer-readable storage medium on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are realized.

The beneficial result of the present invention is that a simple encoding device can be provided, and the accuracy that can be provided is the tenth of a centimeter, that is, 0.1 centimeter.

Description of the drawings

The present invention will be further explained below with reference to the drawings and examples. In the attached drawings, the same reference numerals denote the same components.

Figure 1 shows a code wheel of a digital measuring tape according to the present invention;

Figure 2 shows a roller of a digital tape measure according to the present invention;

Fig. 3 is a schematic diagram showing the cooperation of the code disc and the roller of a digital measuring tape according to the present invention;

Figure 4 shows a system frame diagram of a digital tape measure according to the present invention;

Figure 5 shows a working schematic diagram of a digital tape measure according to the present invention;

Fig. 6 shows a flow chart of a digital tape measuring method according to the present invention.

detailed description

In the following, the concept, specific structure, and technical effects of the present invention will be clearly and completely described with reference to the implementation examples and the accompanying drawings, so as to fully understand the objectives, solutions, and effects of the present invention. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other if there is no conflict. The same reference numerals used throughout the drawings indicate the same or similar parts.

It should be noted that, unless otherwise specified, when a feature is called "fixed" or "connected" to another feature, it can be directly fixed and connected to another feature, or indirectly fixed or connected to another feature. One feature. In addition, the top, bottom, left, right and other descriptions used in this application are only relative to the mutual positional relationship of the various components of this application in the drawings. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

The exemplary embodiments described herein and the drawings should not be considered as limiting. Without departing from the scope of this document and the claims, various mechanical, compositional, structural, electrical and operational modifications, including equivalents, can be made. In some cases, well-known structures and technologies are not shown or described in detail to avoid confusion with the present disclosure. The same reference signs in two or more figures indicate the same or similar elements. In addition, elements and related features described in detail with reference to one embodiment may be included in other embodiments where they are not specifically shown or described in any feasible situation. For example, if an element is described in detail with reference to one embodiment, and the element is not described with reference to the second embodiment, it can also be claimed that the element is included in the second embodiment.

In addition, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. The terminology used in this specification is only for describing specific embodiments, not for limiting the application. The term "and/or" as used herein includes any combination of one or more related listed items.

It should be understood that although the terms first, second, third, etc. may be used in this application to describe various elements, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, without departing from the scope of the present application, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element. Depending on the context, the word "if" as used herein can be interpreted as "when" or "when".

In the embodiment of the present invention, the method steps may be executed in another order. The present invention is not limited to the sequence determined by the described method steps.

Refer to the code wheel of a digital tape measure according to the present invention shown in FIG. 1, and FIG. 2 shows the roller of a digital tape measure according to the present invention. In one embodiment of the present invention, the present invention provides an encoding device for a digital measuring tape, including: a code wheel, the code wheel is circular and has a central through hole; a roller matched with the code wheel, the The center of the roller has a rotating shaft matched with the central through hole, so that the roller can be fixed above the code disc, contact with the code disc and rotate relative to the code disc; and fixed on the roller A metal elastic member; on one side of the code wheel, a plurality of sets of metal contacts protruding from the side are staggered along the radial direction of the one side, and the plurality of sets of metal contacts are not completely covered The one side surface of the code wheel; wherein each of the multiple sets of metal contacts includes one or more metal contacts; the metal elastic members are distributed in a 1/4 circle of the roller, And it includes one or more strip-shaped metal elastic contact bodies that are spaced apart from each other, the number of which is the same as the number of the groups of the plurality of metal contact pieces, so that when the When the roller rotates relative to the code wheel, it can contact with only one metal contact piece in the same group of the multiple sets of metal contact pieces at the same time, and at different times in the same cycle, the metal is elastic The contact relationship between the metal elastic contact body in the component and the multiple sets of metal contacts is unique. Specifically, in an embodiment of the present invention, the cycle is a rotation cycle, that is, the process of the roller relative to the code wheel rotating one circle.

Preferably, in an embodiment of the present invention, the metal elastic member is a spring leaf, as shown in FIG. 2.

Specifically, referring to the schematic diagram of the code wheel and the roller of a digital tape measure according to the present invention shown in FIG. 3, the figure schematically shows how the code wheel and the roller cooperate with each other. The structure composed of the code disc and the spring of the roller is used for level detection. When the spring is in contact with the metal surface of the code disc, the signal detection pin and the signal trigger pin have the same level, so there will be periodicity after the roller rotates once. The level of signal can be judged according to the periodic signal change.

Further, in an embodiment of the present invention, in the multiple groups of metal contacts, the radial distance from the center of each of the metal contacts belonging to the same group to the center of the code wheel is equal, and belongs to different groups. The radial distances from the centers of any two metal contact pieces to the center of the code wheel are not equal. That is, the metal contacts with the same distance to the center of the code wheel belong to the same group.

Further, in an embodiment of the present invention, each of the metal contacts is a circular ring segment with a certain radial width, which has a first arc surface and a second arc surface in the radial direction, wherein The distance from the first arc surface to the center of the code wheel is smaller than the distance from the second arc surface to the center of the code wheel. That is, just because the ring segment has a certain width in the radial direction, the ring segment defines two arc surfaces in the radial direction, and the first arc surface is closer to the code than the second arc surface. The center of the disc, the second arc is farther away from the center of the code disc than the first arc. It should be understood that the above-mentioned first and second expressions are only used to distinguish between different arcs, and do not limit the sequence. Under the premise of not violating the spirit of the present invention, the first arc or the second arc can be closer The center of the code wheel.

Further, in an embodiment of the present invention, among the multiple groups of metal contacts, each of the metal contacts belonging to the same group is evenly distributed in the circumferential direction of a circle formed at the same radial distance, so that they belong to the same group. The center angle formed by the center of the two adjacent contact pieces in the group and the center of the code wheel is equal. It should be understood that the above arrangement is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Under the premise of not departing from the spirit of the present invention, the two adjacent contact members in the same group The center may also be unequal to the central angle formed by the center of the code wheel.

Preferably, in an embodiment of the present invention, the number of the groups of the multiple sets of metal contacts is 4 groups, which is the situation as shown in FIG. 1. It should be understood that the provision of 4 sets of metal contacts is only a preferred embodiment of the present invention. Under the premise of not violating the spirit of the present invention, more sets of metal contacts or fewer sets of metal contacts can be provided. It depends on the accuracy and the ease of processing.

Preferably, in an embodiment of the present invention, the center through hole of the first group of metal contacts closest to the code wheel, and the first arc of the first group of metal contact components is at the center of the code wheel. The central angle of the composition is 26°; the second group of metal contacts is close to the first group of metal contacts and farther away from the center of the code wheel, and the first arc of the first group of metal contacts is The center angle formed by the center of the code wheel is 30°; the third group of metal contacts is close to the second group of metal contacts and farther away from the center of the code disk, and the first group of metal contacts The central angle formed by the first arc of the piece and the center of the code wheel is 13°; the fourth group of metal contacts is close to the third group of metal contacts and farther away from the center of the code wheel, and The central angle formed by the first arc surface of the fourth group of metal contacts and the center of the code wheel is 6°. It should be understood that such an arrangement is only a preferred embodiment of the present invention. On the premise of not violating the spirit of the present invention, the central angle formed by the first arc of each group and the center of the code wheel can be based on Actually need to be set.

Preferably, in an embodiment of the present invention, the diameters of the code wheel and the roller are both φ41, the diameter of the central through hole of the code disk is φ10; the diameter of the rotating shaft of the roller is φ10.6, It should be understood that such a setting method is only a preferred embodiment of the present invention, and other diameter sizes can be set without violating the spirit of the present invention, depending on factors such as the size and range of the measuring tape.

Further, referring to the system framework diagram of a digital tape measure according to the present invention shown in FIG. 4, in an embodiment of the present invention, it further includes a processor, a decoding device, a communication device, and a display device; wherein, the processing The device is connected to the encoding device, the decoding device, the communication device and the display device of the digital tape measure, and is used to send control instructions to the above-mentioned device and perform displacement calculation; the decoding device is connected to the processor and the encoding device, Is used to decode the code generated by the encoding device; the communication device is connected to the processor and used to send the displacement calculated by the processor; the display device is connected to the processor to display the The displacement calculated by the processor.

Preferably, in an embodiment of the present invention, the structure of the code disc device is mainly composed of a rotation level detection sensor composed of a code disc circuit board, a roller and a spring fixed on the roller, which is pre-installed on the code disc circuit board. It is equipped with signal source and signal detection pins. When the measuring tape drives the roller to rotate during the pulling process, the spring plate on the roller will sweep across the copper plane of the code disc. The signal detection pin corresponding to the place where the spring leaf passes will be short-circuited with the signal generation source, so that the signal returned by the detection pin to the main control CPU will generate the same signal as the signal generation source. According to this principle, when the spring sheet scans the copper surface of the code disc at the same time, the four signal detection pins are misaligned and different signals will be sent back to the main control CPU. When the roller turns one circle, the spring leaf will leave a regular serial code on the code disc. The main control CPU calculates the number of repetitions of these serial codes to determine the number of turns of the roller and the current serial code to determine the The angular displacement of the last rotation of the roller. According to the above principles, very precise dimensions can be obtained. According to the regular copper surface on the code wheel, the accuracy of the tape gauge reading to the tenths of centimeters, that is, 0.1 cm, can solve the error value caused by using the number of roller rotations and the circumference to convert the size. The accuracy of reading the value on the master MCU depends on the accuracy of the exposed copper plane spacing on the code disc.

Preferably, referring to the working schematic diagram of a digital tape measure according to the present invention in FIG. 5, the figure shows the situation when the spring sheet sweeps the code disc at a detection moment, and each circle on the code disc represents a signal Detect the pin. When the roller rotates, the spring fixed on the roller is driven to rotate. The 4 electrical signals generated by the place where the spring is swept will be transmitted to the processor at the same time, and at a certain moment, when the spring contacts When it reaches a certain metal contact of the code disc, it is indicated by the code "1". When the spring leaf does not touch a certain metal contact of the code disc, it is indicated by the code "0". In this way, as shown in Figure 5, At a moment, when the springs are in contact with 4 metal contacts at the same time, a 4-bit encoding signal will be generated, such as 1001 and 1110 in the figure. The processor converts the received electrical signal into corresponding displacement information. In this way, the physical quantity measured by the encoding device will be converted into an electrical signal based on these four pins, and the processor will calculate and process the electrical signal and then convert it into the digital quantity of the current measuring tape for display or transmission through the communication device. The figure shows the signal source pins and the signal test pins of PA1, PA2, PA3, and PA4. Among them, the signal test pins of PA1, PA2, PA3, and PA4 correspond to a set of metal contacts, as shown in the figure. As shown, PA1 is on the outermost circle, and PA4 is on the innermost circle; the single-chip microcomputer presets PA0 to always output a square wave signal, and PA1, PA2, PA3, and PA4 are used as signal input capture pins, when the spring is scanned on the code disc , If the spring leaf is in contact with one of the metal contacts, such as PA1 and the metal contact, the PA0 pin and PA1 pin will be short-circuited, thus generating a contact signal, if the spring leaf is not with any metal contact Contact, no short circuit occurs, no contact signal is generated.

Before the measuring tape rotates, the position of the spring leaf leaves four level signals (such as 1001) on the four test pins on the code wheel, and the measuring tape is pulled from 0 to 3 meters. At this time, a series of serial codes from 1001 to 1110 can be measured from these four signal pins, and then the serial codes obtained from 1001 to 1110 after the tape is drawn are calculated how many times are repeated in total. Cycle string code. Because after all, the spring leaf will return to the point of 1001 when it rotates one circle and repeats again, and then it loops the last string code number again. According to this rule, 3000 serial codes are obtained, and a total of 50 laps are repeated. That is, 60 serial codes in a circle. According to this rule, the preset signal serial code will be measured on these four pins every time the tape is pulled out 1 cm, that is, the one-to-one corresponding value can be obtained by looking up the table. According to this rule, we can Determine the size of the tape we pulled out. The table form diagram is as follows:

皮尺尺寸(cm)Measuring tape size (cm)	码盘对应代码(码盘出来值)Code disk corresponding code (code disk output value)	码盘圈数计算(处理器来计算)Calculating the number of encoder turns (calculated by the processor)
0.00.0	10011001	00
1.01.0	10011001	11
2.02.0	10011001	22
0.50.5	11001100	00
1.51.5	11001100	11
2.52.5	11001100	22

Further, according to the foregoing discussion, in an embodiment of the present invention, the measuring tape proposed by the present invention can also be designed according to the required accuracy. For example, if the required accuracy is centimeters, the measuring tape of the present invention When 1 cm is pulled out, only one changing signal string code is needed to correspond to it. In this way, we can find out the position of the tape after pulling it out by looking up the table. For example, the total length of the measuring tape is 3 meters, and the corresponding measuring tape rotates for a total of 50 cycles, and 60 signal strings are needed on the code disc (that is, the four signal pins are from 1001 to 1110 at the same time). Therefore, the code disc It is necessary to design correspondingly 60 sets of signal strings. Therefore, according to this signal set, a code disk with 60 sets of signal strings or 70 sets of signal strings can be designed.

Further, referring to the flow chart of a digital tape measuring method according to the present invention shown in FIG. 6, it includes the following steps: A. Generated at each detection time point, the metal elastic contact body is respectively the metal contact and the generating The code group formed by contact or no contact; B. According to the size of the code disc, the setting method of the metal contact, and the detection time interval, the corresponding angular displacement corresponding to two adjacent codes in the code group is obtained Relationship; C. Determine the displacement based on the above-mentioned corresponding relationship and the number of codes in the received code group. In an embodiment of the present invention, the above-mentioned step C can also calculate the displacement according to the law of period as discussed above.

Finally, in an embodiment of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, characterized in that the computer program is executed by a processor to implement the steps of the above method.

It should be realized that the embodiments of the present invention can be realized or implemented by computer hardware, a combination of hardware and software, or by computer instructions stored in a non-transitory computer-readable memory. The method can be implemented in a computer program using standard programming techniques, including a non-transitory computer-readable storage medium configured with a computer program, wherein the storage medium so configured enables the computer to operate in a specific and predefined manner-according to specific embodiments The methods and drawings described in. Each program can be implemented in a high-level process or object-oriented programming language to communicate with the computer system. However, if necessary, the program can be implemented in assembly or machine language. In any case, the language can be a compiled or interpreted language. Furthermore, the program can be run on a programmed application specific integrated circuit for this purpose.

Further, the method can be implemented in any type of computing platform that is operably connected to a suitable computing platform, including but not limited to personal computers, minicomputers, main frames, workstations, network or distributed computing environments, separate or integrated computer platforms , Or communicate with charged particle tools or other imaging devices, etc. Aspects of the present invention can be implemented by machine-readable codes stored on non-transitory storage media or devices, whether removable or integrated into a computing platform, such as hard disks, optical reading and/or writing storage media, RAM, ROM, etc., so that they can be read by a programmable computer, and when the storage medium or device is read by the computer, it can be used to configure and operate the computer to perform the processes described herein. In addition, the machine-readable code, or part thereof, can be transmitted through a wired or wireless network. When such media include instructions or programs that implement the steps described above in combination with a microprocessor or other data processors, the invention described herein includes these and other different types of non-transitory computer-readable storage media. When programming according to the methods and techniques of the present invention, the present invention also includes the computer itself.

The embodiments of the present disclosure are described herein, including the best mode known to the inventor for carrying out the present invention. After reading the above description, the changes of these described embodiments will become apparent to those skilled in the art. The inventor hopes that the skilled person will adopt such modifications as appropriate, and the inventor intends to practice the embodiments of the present disclosure in a manner different from that as specifically described herein. Therefore, subject to applicable laws, the scope of the present disclosure includes all modifications and equivalents of the subject matter recited in the appended claims. In addition, the scope of the present disclosure encompasses any combination of the above-mentioned elements in all possible variations thereof, unless otherwise indicated herein or otherwise clearly contradictory to the context.

Although the description of the present invention has been quite detailed and specifically described several of the described embodiments, it is not intended to be limited to any of these details or embodiments or any special embodiments, but should be regarded as by reference The appended claims take into account the prior art to provide a broad possible interpretation of these claims, thereby effectively covering the predetermined scope of the present invention. In addition, the above description of the present invention with the embodiments foreseen by the inventor is to provide a useful description, and those insubstantial changes to the present invention that are not currently foreseen can still represent equivalent changes to the present invention.

Therefore, the present specification and drawings should be understood in an illustrative rather than restrictive sense. However, it will be obvious that various modifications and changes can be made to this application without departing from the broader spirit and scope of the application as set forth in the claims.

Other variations are within the spirit of this application. Therefore, although the disclosed technology can tolerate various modifications and alternative configurations, some of its embodiments have been shown in the drawings and described in detail above. However, it should be understood that it is not intended to limit the application to one or more specific forms disclosed; on the contrary, it is intended to cover all modifications falling within the spirit and scope of the application as defined in the appended claims , Alternative structures and equivalents.

Claims

An encoding device for digital tape measure, including:

Code disc, said code disc is circular and has a central through hole;

A roller matched with the code wheel, the center of the roller wheel has a rotating shaft matched with the central through hole, so that the roller can be fixed above the code wheel, contact with the code wheel and relative to the code wheel Disk rotation; and

A metal elastic member fixed on the roller; characterized in that,

On one side of the code wheel, a plurality of sets of metal contacts protruding from the side are arranged in a radial direction and staggered along the one side surface, and the multiple sets of metal contacts do not completely cover the code wheel The one side surface; wherein, each of the plurality of sets of metal contacts includes one or more metal contacts;

The metal elastic member is distributed in the 1/4 circle of the roller, and includes the same number as the number of the groups of the plurality of metal contact pieces, and the metal contact pieces are matched with each other and spaced apart from each other. One or more strip-shaped metal elastic contact bodies, so that when the roller rotates relative to the code wheel, it can contact only one metal contact piece in the same group of the multiple sets of metal contact pieces at the same time In addition, at different moments in the same period, the contact relationship between the metal elastic contact body in the metal elastic member and the multiple sets of metal contacts is unique.
The encoding device according to claim 1, wherein, in the multiple sets of metal contacts, the radial distance from the center of each of the metal contacts belonging to the same set to the center of the code wheel is equal, and, The radial distances from the centers of any two metal contacts belonging to different groups to the center of the code wheel are not equal.
The encoding device according to claim 1, wherein each of the metal contacts is a circular ring segment with a certain radial width, which has a first arc surface and a second arc surface in the radial direction, Wherein, the distance from the first arc surface to the center of the code wheel is smaller than the distance from the second arc surface to the center of the circle.
The encoding device according to claim 3, characterized in that, among the multiple sets of metal contacts, each of the metal contacts belonging to the same set is evenly distributed in the circumferential direction of a circle formed at the same radial distance to The center angle formed by the center of two adjacent contact pieces belonging to the same group and the center of the code wheel is made equal.
4. The encoding device according to claim 4, wherein the number of groups of the plurality of metal contacts is 4 groups.
The encoding device according to claim 5, wherein the first set of metal contact members are closest to the central through hole of the code disk, and the first arc of the first set of metal contact components is connected to the center of the code disk. The central angle formed by the center of the circle is 26°; the second group of metal contacts is close to the first group of metal contacts and farther away from the center of the code wheel, and the first arc of the first group of metal contacts The center angle formed by the surface and the center of the code disk is 30°; the third group of metal contacts is close to the second group of metal contacts and farther from the center of the code disk, and the first group The central angle formed by the first arc of the metal contact and the center of the code wheel is 13°; the fourth group of metal contacts is close to the third group of metal contacts and farther away from the center of the code wheel And the central angle formed by the first arc of the fourth group of metal contacts and the center of the code wheel is 6°.
The encoding device according to claim 1, wherein the diameter of the code wheel and the roller are both φ41, the diameter of the center through hole of the code disk is φ10; the diameter of the rotating shaft of the roller is φ10. 6.
A digital measuring tape comprising the encoding device according to any one of claims 1-7, further comprising a processor, a decoding device, a communication device, and a display device; wherein,

The processor is connected to the encoding device, the decoding device, the communication device and the display device of the digital tape measure, and is used to send control instructions to the above-mentioned device and perform displacement calculation;

The decoding device is connected to the processor and the encoding device, and is used to decode the code generated by the encoding device;

The communication device is connected to the processor, and is used to send the displacement calculated by the processor;

The display device is connected to the processor and is used for displaying the displacement calculated by the processor.
A method for measuring displacement using the digital tape measure according to claim 8, characterized in that it comprises the following steps:

A. Generated at each detection time point, the metal elastic contact body is respectively the code group formed by the metal contact or no contact;

B. According to the size of the code disc, the setting mode of the metal contact, and the detection time interval, the corresponding relationship between the angular displacements of the two adjacent codes in the code group is obtained;

C. Determine the amount of displacement according to the above-mentioned correspondence and the number of codes in the received code group.
A computer-readable storage medium with a computer program stored thereon, wherein the computer program is characterized in that when the computer program is executed by a processor, the steps of the method described in claim 9 are implemented.