CN104077004A - Action detection method and pointer - Google Patents
Action detection method and pointer Download PDFInfo
- Publication number
- CN104077004A CN104077004A CN201310122732.3A CN201310122732A CN104077004A CN 104077004 A CN104077004 A CN 104077004A CN 201310122732 A CN201310122732 A CN 201310122732A CN 104077004 A CN104077004 A CN 104077004A
- Authority
- CN
- China
- Prior art keywords
- receiving cycle
- cycle
- receiving
- pointer
- action
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Position Input By Displaying (AREA)
- Measuring Fluid Pressure (AREA)
Abstract
The invention relates to an action detection method and a pointer for a digital panel, a learning machine, a hand sign and the like. The method and the pointer achieve the effect that a Q value and the frequency of a pointer resonance circuit are detected simultaneously and independently.
Description
Technical field:
The present invention relates to action method for detecting and the pointers such as Digitizing plate, point reader, hand mark.
Background technology:
Simple and clear in order to describe, the pen in Digitizing plate, point reader, mouse (being different from common mouse is a kind of position indicator of mouse-like) etc. is called pointer, the position of pointer (comprises x, y, z axle), attitude (comprises and x, y, z axle clamp angle, pointer spin angle), pressure (comprises the contact force between nib and panel, the grip of finger gripping pointer), key-press status etc. are all distinguished the difference action of corresponding hand-held pen, the amount to be checked that we detect these pass through electromagnetic coupled modes relevant to pointer characteristic is referred to as action variable, the detecting of these amounts to be checked is called action variable and detects, to become action detection device with the supporting device that detects action variable of pointer, action detection device comprises again antenna array and action detecting circuit, antenna array is comprised of a plurality of sub antennas again, pointer is called to action sensor together with action detection device, action sensor can detect everything variable above-mentioned, also can detect wherein one or several, or also do not mention above other action variable.
The sensor has a common characteristic to rely on pointer and antenna array electromagnetic coupled mode to detect the action of pointer, in patent " 200420003299.8 " " 200910075485x " technology, obtained practice, wherein " 200420003299.8 " are in pointer, to have battery, pointer only has Electromagnetic Launching state, does not have the action of electromagnetism receive status to detect technology, and " 200910075485x " is that in pointer, existing Electromagnetic Launching has again the action of electromagnetism accepting state to detect technology.Principle is that the mode by scanning accesses sub antenna to be checked sampling successively, according to the data of sampling, calculates action variable.
Due to said apparatus utilization is the action that magnetic coupling mode detects pointer, wherein a kind of scheme is the action that the variation that detects resonance frequency in pointer detects hand, such as working pressure sensor converts pressure to the variation of resonant capacitance, thereby affect resonance frequency, use for another example button actuation of keys to be converted to the variation of resonant capacitance, thereby affect resonance frequency, then according to the variation division operation of resonance frequency.But while sometimes needing a plurality of variable to be checked, the interference between variable can affect whole system function.
Summary of the invention:
In order to overcome the above problems, the object of the invention is to:
Realize a kind of action sensor;
Detect the frequency of resonant circuit
Detect the Q value of resonant circuit;
Detected pressures;
Detect button;
Distinguish different time writers;
Communication for time writer and pick-up unit;
Improve detection speed.
In order to realize object of the present invention, the invention of technical scheme 1 is a kind of action method for detecting, a sense cycle, comprises Electromagnetic Launching cycle, the first receiving cycle, the second receiving cycle; Different or end time difference of start time of the first cycle receiving and the second receiving cycle or beginning, end time are all different.Two time period data at least two sense cycle of sampling, as further use relative method calculated rate or Q value, lay the first stone.
The invention of technical scheme 2 is according to the action method for detecting described in technical scheme 1, comprises step: calculate the sample magnitude of the first receiving cycle, calculate the sample magnitude of the second receiving cycle; The raw data of using the sample magnitude of the first receiving cycle and the sample magnitude of the second receiving cycle to detect as calculating action.
The invention of technical scheme 3 is according to the action method for detecting described in technical scheme 2, comprises step, calculates the ratio of the sample magnitude of the first receiving cycle and the sample magnitude of the second receiving cycle.In the situation that using lock detector, according to the mistiming between amplitude ratio, local frequency, the first receiving cycle and the second reception, can calculate the Q value of resonant circuit to be measured.
The invention of technical scheme 4 is action method for detecting according to claim 3, it is characterized in that:
According to the ratio of the sample magnitude of the sample magnitude of the first receiving cycle and the second receiving cycle, drop on the identity of specifying pointer in different specified scopes.
The invention of technical scheme 5 is action method for detecting according to claim 3, it is characterized in that:
According to the ratio of the sample magnitude of the sample magnitude of the first receiving cycle and the second receiving cycle, drop on and in different specified scopes, carry out specify data transfer bit.
The invention of technical scheme 6 is according to the action method for detecting described in technical scheme 1, comprises step, calculates the sampling phase of the first receiving cycle, calculates the sampling phase of the second receiving cycle; The raw data of using the sampling phase of the first receiving cycle and the sampling phase of the second receiving cycle to detect as calculating action.
The invention of technical scheme 7 is according to the action method for detecting described in technical scheme 6, comprises step, calculates the poor of the sampling phase of the first receiving cycle and the sampling phase of the second receiving cycle.In the situation that using lock detector, according to the mistiming between phase differential, local concussion frequency, the first receiving cycle and the second receiving cycle, can calculate the frequency of resonant circuit to be measured.Compare only have a receiving cycle situation more accurately, antijamming capability is stronger.
The invention of technical scheme 8 is action method for detecting according to claim 1, it is characterized in that: the first receiving cycle in different sense cycle is compared from the first receiving cycle, the second receiving cycle in different sense cycle is compared with the second receiving cycle, their start time difference or end time difference or start time, end time are all different.By the first different receiving cycles and the mistiming of second round are set, when detecting Q value, can regulate the first receiving cycle amplitude and the second receiving cycle amplitude ratio to prevent excessive or too small, make the error of the generation of signal conditioning circuit drop on ideal range; When detecting frequency, can regulate the first receiving cycle phase place and the second receiving cycle phase differential to prevent excessive or too small, make phase-detection error drop on ideal range, prevent that phase differential from surpassing 360 degree, produce the false frequency that detects.
The invention of technical scheme 9 is action method for detecting according to claim 1, it is characterized in that: comprise the 3rd receiving cycle.
The invention of technical scheme 10 is a kind of pointer, it is characterized in that, comprises telefault to be checked, and described telefault to be checked and electric capacity form resonant circuit; Comprise resistive element; Regard all inductance, electric capacity as loss-free element, and the side circuit equivalence that comprises described resistive element is become to parallel resistance, after resistance in series, the actual value of described resistive element is less than equivalent parallel resistance value and is greater than series impedance.Can be the variable resistor of different variation ranges, access pointer resonant circuit, and the Q value variation that produces specified scope.
Telefault to be checked, is open telefault, can launch reception electromagnetic induction, is used to refer to position.
Accompanying drawing explanation:
The schematic diagram of the pointer of the existing scheme of Fig. 1
Fig. 2 pointer schematic diagram with pressure-capacitive transducer nib, resistance button of the present invention
Fig. 3 the present invention is with the pointer schematic diagram of pressure-electric resistance sensor nib, electric capacity button
Fig. 4 pointer schematic diagram of the present invention
The principle schematic of Fig. 5 detecting circuit
Fig. 6 signal conditioning circuit schematic diagram
Sense cycle oscillogram of the existing scheme detecting circuit of Fig. 7
Sense cycle oscillogram of Fig. 8 detecting circuit of the present invention
Fig. 9 resistance series system resonant circuit schematic diagram
Figure 10 resistance parallel way resonant circuit schematic diagram
Figure 11 resistance cut-in method schematic diagram group
The meaning of numeral, label representative in figure:
R1, R11, R12: equivalent resistance
R2, R21, R22, R23, R24: pressure-electric resistance sensor
C2: pressure-capacitive transducer
L1, L11, L12, L13, L14: treat test coil
C1, C3, C11, C12, C13, C14, C15: electric capacity
R3: resistance
S1: keyswitch
S2: analog switch
S3: transmitting receives control simulation switch
1; Pointer
2: antenna array
21: sub antenna
22: sub antenna
41: amplifying circuit
42: filtering circuit
43: synchro detection circuit
44:A/D converter
5: calculating part
PS1: test point is positioned at analog switch S3 control line
P41: test point is positioned at amplifier 41 inputs
P42: test point is positioned at wave detector 43 inputs
P43: test point is positioned at lock detector 43 output Q items
P44: test point is positioned at lock detector 43 output I items
P11: test point is positioned at position indicator pointer
P12: test point is positioned at position indicator pointer
Point potential difference between P11-P12: test point P11 and P12
Embodiment:
The schematic diagram of passive pointer (a kind of time writer) as shown in Figure 1, the resonant circuit that pointer coil L1 to be checked and capacitor C 1 form forms, wherein R1 is the lossy equivalent resistance that comprises conductor resistance loss, dielectric loss, launch loss, and its resonance frequency is determined by the value of L1, C1; L1 is opening inductance, when passing the coil of inductance L 1, the vicissitudinous magnetic line of force can produce voltage, inductance L 1 meeting transmission of electromagnetic signals when vicissitudinous electric current flows through inductance L 1, when the identical electromagnetic signal of the resonance frequency by forming with L1, C1 encourages, the resonant circuit that in pointer, L1, C1 form produces resonance, continues to keep decay concussion echo when pumping signal is cancelled.C2 is pen point pressure-capacitive transducer, when pressure increases, electric capacity increases, thereby the resonance frequency of pointer is reduced, the pressure that the variation of frequency can detect nib changes, button S1 connects capacitor C 3, C3 is greater than the maximal value of variable capacitance C2, resonance frequency when thereby button is pressed is all lower than the frequency under any pressure, whether all buttons of can distinguishing are pressed, but because the effect of trembling of button is difficult to the correct pen point pressure that detects in having the process of button, button and pen point pressure detect conflict.
As shown in Figure 2 be the pointer with pressure-capacitive transducer nib, resistance button, button S1 is connected with resistance R 3, be used for changing the Q value of resonant circuit, and button whether press affect only have Q value, on not impact of frequency, so can eliminate the interference between button and pen point pressure detection in principle like this.In figure, only drawn a button, certainly configured a plurality of buttons and be not a problem.
As the position indicator pointer of Fig. 3 with pressure-electric resistance sensor nib, electric capacity button, button S1 is connected with capacitor C 3, be used for changing the frequency of resonant circuit, and button whether press the frequency values affecting, on the not impact of Q value, what pen point pressure changed is the Q value of resonant circuit, so can eliminate the interference between button and pen point pressure detection in principle like this.
As Fig. 4, be the pointer with pressure-capacitive transducer nib, pressure-electric resistance sensor button, when button R2 is subject to pressing, the change of resistance can change the Q value of resonant circuit, and button press pressure influence only have Q value, on not impact of frequency, so can eliminate the interference between key press and pen point pressure detection in principle like this.Such benefit is to carry being total to two pressure detection.
The theory diagram that the pointer action of electromagnetic coupled mode detects scheme as shown in Figure 5, whole system is comprised of pointer, action detection device, action detection device comprises antenna array and signal conditioning circuit, antenna array comprises the sub antenna that a plurality of x axles, y axle are arranged respectively, action detecting circuit is comprised of sub antenna selector switch, filtering and amplifying circuit, lock detector, analog to digital converter, cpu, AC signal generator, and filtering and amplifying circuit, lock detector, analog to digital converter are made to the as a whole signal conditioning circuit that is called.
If Fig. 6 is the signal conditioning circuit that detects pointer resonance frequency, conventional circuit structure and circuit structure of the present invention are basic identical, difference is that the Waveform Control in each parts is different, as shown in Figure 7 in a sense cycle in classic method signal generator first to antenna transmission electromagnetic signal, then stop the local oscillation signal (shown in the waveform of test point P32) that transmitting finishes the transmitting cycle, a receiving cycle is then provided to lock detector; There is in the present invention as shown in Figure 8 in a sense cycle first signal generator to antenna transmission after the cycle, the local oscillation signal of the first receiving cycle, the second receiving cycle is then provided to lock detector, at the first receiving cycle, finishes respectively, the second receiving cycle ADC synchronous detection data of sampling respectively twice while finishing.
Q be worth to detect principle below, because the Q value of resonant circuit is when different, and the multiple of its amplitude attenuation difference within the identical time; Different initial magnitude size in resonant circuit when Q value is constant, within the identical time, the multiple of its amplitude attenuation is constant, and this is the fundamental property of resonant circuit.Consider this character, the amplitude detecting due to the lock detector of the first receiving cycle and the second receiving cycle has represented the concussion amplitude in oscillating circuit, so use the detected amplitude of the first receiving cycle and the detected amplitude ratio of the second receiving cycle, the mistiming of sampling can obtain Q value very much.Gain that it should be noted that the amplifying circuit in the first receiving cycle and the second receiving cycle can be arranged to different values, as long as the value of gain is the known correct Q value that just can calculate.Can omit in addition the worth process of Q of calculating, such as amplitude being compared directly as the corresponding raw data of pressure, again by calibrating and using calibration data linear transformation also can detect correct pressure value, if pressure-electric resistance sensor is replaced with to other X-electric resistance sensors, also can detect the physical quantity of other appointments.
See on the other hand the detection of frequency, in legacy frequencies detection method, phase value that need not the second receiving cycle, but supposition, the local oscillator in transmitting cycle is synchronizeed with the concussion of resonant circuit in pointer during end cycle in transmitting, utilizes the frequency of phase place in receiving cycle and local oscillator directly to calculate the frequency of resonant circuit in pointer; But consider and in the transmitting cycle, want the resonance of pointer and transmitted waveform synchronously to want more transmitting the time, when the time of transmitting more in short-term, when particularly the resonance frequency of emission signal frequency and pointer has deviation, often local oscillator and pointer resonance have phase differential, and this makes frequency detecting have larger error; The present invention uses the phase difference calculating frequency of two receiving cycles to solve this problem, and reason is no matter whether transmitting during end cycle, transmits and synchronize with the resonance in pointer, two receiving cycles to detect phase differential constant.
Having detection Q to be worth after method below, other that have a look the detection of Q value are applied relevant embodiment.
If different damping resistances is set in different pointers, produce different Q values, can by detecting the Q value of pointer, distinguish the identity of current pointer of working, such as appointment is pencil or rubber.Can certainly use additive method to set Q value, such as using the loss of eddy current change inductance, use the means such as electric capacity of different losses.
If while transmitting data between pointer and testing circuit, can use different Q values in a sense cycle, to transmit the data that surpass a bit.Such as different Q value Q0 is set, Q1, Q2, Q3, when pick-up unit needs the data of sending in reception pointer, when transmitting end cycle, by the cpu in pointer, analog switch in steering needle, by in the resonant circuit in the resistance access pointer of appointment, and make the Q value of resonant circuit be respectively Q0, Q1, Q2, in Q3 one, pick-up unit just can be according to Q value being detected, and drop on Q0 according to Q value, Q1, Q2, near in Q3, which is worth, the data that judgement pointer sends are 0, 1, 2, which in 3, 2 Bit data transmission have been realized, if use more rank, can once send more bit.
In the present embodiment, used the lock detector that can simultaneously detect measured signal amplitude and phase place, object is to detect frequency and Q value simultaneously, if we only expect one of them physical quantity, as detect Q value and can use common the first receiving cycle of wave detector output and the amplitude of the second receiving cycle to calculate Q value, as detected frequency, can use the first receiving cycle of phase detector output and the phase calculation frequency of the second receiving cycle; Common wave detector and phase detector can certainly be set simultaneously to be detected and detects frequency and Q value simultaneously.Common wave detector comprises diode detector, zero passage detection wave detector etc., and phase detector comprises phaselocked loop phase detector, pulse phase discriminator etc.
In addition in some cases, need to control the mistiming of the first receiving cycle and the second receiving cycle in different sense cycle, if time of reception poor very long, pointer resonant circuit Q value is less, the signal amplitude that may produce the first receiving cycle is too large, the second receiving cycle amplitude is too little, even if use programmable amplifier, specify the gain of the second receiving cycle maximum, its signal amplitude is still too little, at this moment just should reduce the mistiming of the first receiving cycle and the second receiving cycle; In addition when detecting frequency, if that the frequency of local oscillator and pointer resonance frequency differ is large, the mistiming of the first receiving cycle and the second receiving cycle is longer, possible make actual phase difference be greater than 360 degree, and lock detector can only detect the value of 0 °-360 °, so can produce mistake, so should use in this case less time of reception poor.The problem solving above can also arrange more receiving cycle, and in one-time detection, in the cycle, sample many group amplitudes, phase data, select optimal data as required, calculates Q value, the frequency of pointer, preferably uses three receiving cycles.
In some cases, because the value dynamic range of pressure-electric resistance sensor is undesirable, conventionally show as the series system of Fig. 9 is used sensor resistance and replace equivalent resistance, accessing resistance makes too greatly the Q value of resonant circuit too little, be not suitable in pointer, and by using sensor resistance to replace equivalent resistance as the parallel way of Figure 10, access the too little Q value of resonant circuit that makes of resistance too little, be not suitable in pointer; The way of dealing with problems be need to be as shown in figure 11 various method of attachment, their common feature is when it converts to as Fig. 9 equivalent electrical circuit, the resistance of actual access is greater than equivalent resistance R11, when it converts the equivalent electrical circuit as Figure 10 to, the resistance of actual access is less than equivalent resistance R12, and the connected mode of these forms is by regulating relevant inductance, capacitance can be easier to find suitable configurations.Such type of attachment is brought a spinoff, sensor can affect the frequency of resonant circuit when regulating resonant circuit Q value, but consider, the variation of Q value has definite impact for resonance frequency, this impact can be defined as Q value frequency error in advance, so while having the sensor of the frequency that changes in addition in resonant circuit, can be the frequency that first detects resonant circuit, then deduct the special actual value to sensor of Q value-frequency error; By such calculating separated influencing each other of Q value sensor and frequency sensor.
Note: the embodiment that this instructions is recorded is preferred embodiment, and object and means that it can illustrate invention on the whole, be not that invention example is exhaustive.
Claims (10)
- Action a method for detecting, it is characterized in that:A sense cycle comprises transmitting cycle and receiving cycle;Described receiving cycle comprises the first receiving cycle, the second receiving cycle;Start time of the first cycle receiving and the second receiving cycle is different or the end time is different or beginning, end time are all different.
- 2. action method for detecting according to claim 1, is characterized in that:Comprise step, calculate the sample magnitude of the first receiving cycle, calculate the sample magnitude of the second receiving cycle;The raw data of using the sample magnitude of the first receiving cycle and the sample magnitude of the second receiving cycle to detect as calculating action.
- 3. action method for detecting according to claim 2, is characterized in that:Comprise step, calculate the ratio of the sample magnitude of the first receiving cycle and the sample magnitude of the second receiving cycle.
- 4. action method for detecting according to claim 3, is characterized in that:According to the ratio of the sample magnitude of the sample magnitude of the first receiving cycle and the second receiving cycle, drop on the identity of specifying pointer in different specified scopes.
- 5. action method for detecting according to claim 3, is characterized in that:According to the ratio of the sample magnitude of the sample magnitude of the first receiving cycle and the second receiving cycle, drop on and in different specified scopes, carry out specify data transfer bit.
- 6. action method for detecting according to claim 1, is characterized in that:Comprise step, calculate the sampling phase of the first receiving cycle, calculate the sampling phase of the second receiving cycle;The raw data of using the sampling phase of the first receiving cycle and the sampling phase of the second receiving cycle to detect as calculating action.
- 7. action method for detecting according to claim 6, is characterized in that:Comprise step, calculate the poor of the sampling phase of the first receiving cycle and the sampling phase of the second receiving cycle.
- 8. action method for detecting according to claim 1, is characterized in that:The first receiving cycle in different sense cycle is compared from the first receiving cycle, the second receiving cycle in different sense cycle is compared with the second receiving cycle, and their start time difference or end time difference or start time, end time be difference all.
- 9. action method for detecting according to claim 1, is characterized in that:Comprise the 3rd receiving cycle.
- 10. a pointer, is characterized in that:Comprise telefault to be checked, described telefault to be checked and electric capacity form resonant circuit;Comprise resistive element, in order to control the Q value of described resonant circuit;Regard all inductance, electric capacity as loss-free element, and the side circuit equivalence that comprises described resistive element is become to parallel resistance, after resistance in series, the actual value of described resistive element is less than equivalent parallel resistance value and is greater than series impedance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310122732.3A CN104077004B (en) | 2013-03-28 | 2013-03-28 | Motion detection method and pointer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201310122732.3A CN104077004B (en) | 2013-03-28 | 2013-03-28 | Motion detection method and pointer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104077004A true CN104077004A (en) | 2014-10-01 |
| CN104077004B CN104077004B (en) | 2021-03-26 |
Family
ID=51598308
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201310122732.3A Active CN104077004B (en) | 2013-03-28 | 2013-03-28 | Motion detection method and pointer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104077004B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105892718A (en) * | 2014-11-27 | 2016-08-24 | 崔伟 | Magnetic finger fastener |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH031213A (en) * | 1989-05-29 | 1991-01-07 | Pentel Kk | Information input device |
| CN101174192A (en) * | 2006-10-31 | 2008-05-07 | 株式会社华科姆 | Position-detecting apparatus and position-indicating device |
| CN101685366A (en) * | 2008-09-26 | 2010-03-31 | 汉王科技股份有限公司 | Electromagnetic induction device with multi-touch function |
-
2013
- 2013-03-28 CN CN201310122732.3A patent/CN104077004B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH031213A (en) * | 1989-05-29 | 1991-01-07 | Pentel Kk | Information input device |
| CN101174192A (en) * | 2006-10-31 | 2008-05-07 | 株式会社华科姆 | Position-detecting apparatus and position-indicating device |
| CN101685366A (en) * | 2008-09-26 | 2010-03-31 | 汉王科技股份有限公司 | Electromagnetic induction device with multi-touch function |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105892718A (en) * | 2014-11-27 | 2016-08-24 | 崔伟 | Magnetic finger fastener |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104077004B (en) | 2021-03-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR960001648B1 (en) | Coordinate input system and the input pen | |
| CN105474147A (en) | Capacitive touch system | |
| CN106643826B (en) | The detection circuit and detection method of LC resonance formula sensor | |
| CN103727964B (en) | A kind of mechanics parameter based on LC resonant transducer measures system and measuring method | |
| CN103140820B (en) | For detecting the method for grasping and the sensor device of handheld device | |
| CN103456156A (en) | Long-distance passive wireless sensor remote-measuring system with working frequency adjustable | |
| CN103001627A (en) | Trimming control system for resonance frequency of quartz crystals | |
| CN109357610B (en) | STM 32-based multifunctional magnetostrictive displacement measuring instrument and measuring method | |
| CN111541442A (en) | Method for resolving inductance value of proximity sensor | |
| CN103512592A (en) | Wireless passive LC resonance sensor detecting circuit and corresponding information acquiring method | |
| CN104077004A (en) | Action detection method and pointer | |
| Barbot et al. | Gesture recognition with the chipless RIFD technology | |
| EP2339501A1 (en) | Near field communication devices | |
| CN105468211A (en) | Data transmission method, system and device between capacitive stylus and touch screen | |
| EP2661812B1 (en) | Sensor device and method for capacitive proximity detection | |
| CN111464206A (en) | Automatic impedance matching adjusting device and method for current coupling type human body communication | |
| CN107908299A (en) | A kind of processing method of electromagnetic signal, apparatus and system | |
| CN111522456B (en) | Double-magnetic core handwriting digital pen | |
| CN203617975U (en) | A frequency modulation apparatus used for resistivity measurement while drilling | |
| CN110426064A (en) | Wireless sourceless sensor and wireless and passive method for sensing | |
| CN103701434B (en) | A kind of frequency modulation device for LWD resistivity log and method | |
| US11125853B2 (en) | System and method for determining position of a receiver relative to a transmitter | |
| CN113970792B (en) | Radio wave perspective instrument receiving system and receiving method thereof | |
| CN108780146B (en) | Method for determining the distance between a vehicle and an identifier | |
| CN211830762U (en) | Automatic impedance matching adjusting device for current coupling type human body communication |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |