A method and system for hover multi-cell touch sensitivity control

Abstract

The application discloses a kind of over-the-air multi-unit touch display systems, including the circuit board, support, light barrier layer and diaphragm arranged in sequence, the position corresponding to the touch sensing area of touch display unit is set on the circuit board, the air layer formed between touch point position and touch sensing area is formed through the lamp cavity opened in support, and the touch display unit is formed by the touch sensing area on the circuit board, the lamp cavity opened in support and diaphragm;Display system is provided with multiple adjacent touch display units, control system receives the touch signal of touch sensing area and processes signal, in the case where touch signal is identified with appropriate sensitivity, eliminate the signal interference of adjacent touch display unit, and accurately identify the touch signal of predetermined target touch display unit.Processing signal in this way improves signal quantity, reduces noise, realizes longer interval over-the-air touch, and can realize the requirement of signal sensitivity.

Description

Technical Field

[0001] This invention belongs to the field of touch display technology, specifically relating to a method and system for controlling the sensitivity of multi-unit touch in the air. Background Technology

[0002] When a display screen has multiple touch units, the signals between the touch units will affect each other. When the system has low sensitivity to touch signal detection, the mutual influence is weak. However, when the system has high sensitivity to touch signal detection, touching one unit will affect other units.

[0003] Chinese invention patent CN118170274A discloses a doorless touch display system for a household refrigerator, comprising a circuit control unit and an auxiliary structural unit. The auxiliary structural unit is mounted on the circuit control unit via adhesive bonding. When a touch button is pressed, the corresponding touch-sensitive PAD acquires the touch signal. The acquired touch signal is fed back to a touch chip via a control circuit etched on a PCB substrate. The touch chip detects and analyzes the touch signal and generates a corresponding touch display scheme result. The display scheme result is sent to an LED display unit electrically connected to the PCB substrate for display. This doorless touch display system uses a frame to create a gap between the touch panel and the PCB substrate, and utilizes the touch display scheme result built into the control chip, replacing traditional touch display methods such as springs and rubber rings. Existing doorless touch methods require a very small gap to meet sensitivity requirements; increasing the air gap makes accurate touch signal acquisition impossible. Furthermore, it cannot solve the problem of signal interference and mutual influence between multiple adjacent units. Summary of the Invention

[0004] The technical problem solved by this invention is to provide a method and system for controlling the touch sensitivity of an array-type multi-touch unit display system by reducing the mutual interference of signals between adjacent touch units.

[0005] Technical Solution: To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A multi-unit touch display system with air resistance includes a circuit board, a bracket, a light-blocking layer, and a film arranged sequentially. A touch-sensing area is set at the position corresponding to the touch display unit on the circuit board. The touch-sensing area on the circuit board, the lamp cavity opened on the bracket, and the film form a touch display unit. An air layer formed by the lamp cavity opened on the bracket passes through the touch point and the touch-sensing area. The thickness of the air layer is greater than 3mm and less than 5mm. The display system is provided with multiple adjacent touch display units. The control system receives the touch signals from the touch-sensing area and processes the signals. The software algorithm eliminates signal interference from adjacent touch display units, increases the signal quantity, reduces noise, controls sensitivity, and accurately identifies the touch signals of the predetermined target touch display unit.

[0007] Furthermore, the touch sensing area is disposed on the circuit board and correspondingly disposed within the lamp cavity of each touch display unit.

[0008] Furthermore, the touch display unit also includes LED beads, which are disposed on a circuit board inside the lamp cavity; the LED beads are bottom-emitting light sources, and the LED beads are disposed corresponding to the touch sensing area.

[0009] Furthermore, the LED beads are surface-mount LEDs with an average light intensity diffusion angle greater than 170°.

[0010] Furthermore, the height of the lamp cavity is less than or equal to the length and width of the touch sensing area, and the interval between adjacent touch sensing areas is greater than or equal to the height of the lamp cavity.

[0011] Furthermore, the circuit board is disposed on the back of the bracket, and a sealant layer is disposed on the back of the circuit board.

[0012] Furthermore, the light-blocking layer is a black foam disposed between the film and the support, and the black foam is located on the outer periphery of the lamp cavity, blocking the light between adjacent touch display units.

[0013] Furthermore, the display system also includes a panel, and the display unit composed of the circuit board, bracket, light-blocking layer and film is disposed inside the panel, and the panel is mounted on the front control bracket.

[0014] A method for controlling the sensitivity of a multi-unit touch display system with air contact is provided. This method achieves high touch sensitivity in the aforementioned multi-unit touch display system. The control system uses a high-sensitivity processing chip to process touch signals and accurately determine the touch signals of the target touch display unit.

[0015] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0016] (1) The air-sealed multi-unit touch sensitivity control method and system of the present invention can eliminate the need for a light guide plate. The touch sensing area is set on the circuit board, which eliminates the need to set the touch sensing area on the film as in the existing lamp cavity type display structure. This saves material costs and reduces process steps.

[0017] (2) The air-to-air multi-unit touch sensitivity control method and system of the present invention adopts a signal processing method to achieve air-to-air touch over a longer distance and can meet the requirements of signal sensitivity.

[0018] (3) The air-to-air multi-unit touch sensitivity control method and system of the present invention has a signal quantity that is more than 9 times that of the original signal quantity, and the noise is reduced to 1 / 6 of that in the prior art. It meets the signal acquisition and processing requirements of array-type adjacent touch units and reduces signal interference between adjacent touch display units. Attached Figure Description

[0019] Figure 1 This is an exploded view of a multi-unit touch system with air contact.

[0020] Figure 2 This is a schematic diagram of a multi-unit touch system bracket.

[0021] Figure 3 This is a schematic diagram of the circuit board for a multi-unit touch system with air contact.

[0022] Figure 4 This is a schematic diagram of the touch mode of a multi-unit touch system with air contact.

[0023] Figure 5 Schematic diagram of the touch structure of a multi-unit touch system with air contact;

[0024] Figure 6 Schematic diagram of a multi-unit touch system;

[0025] Figure 7 Schematic diagram of signal processing circuit for a multi-unit touch system;

[0026] Figure 8 Circuit diagrams for different numbers of LED beads;

[0027] Figure 9 Circuit diagrams showing different numbers of LED beads;

[0028] Figure 10 Noise results for setting a single LED bead in the touch sensing area;

[0029] Figure 11 Noise results for setting three LED beads in the touch sensing area;

[0030] Figure 12 The noise results are compared between having one and three LED beads in the touch sensing area;

[0031] Figure 13 These are the parameters of the LED beads used in this invention;

[0032] Figure 14 This invention relates to the circuit principle of a multi-unit touch display system with air contact. Figure 1 ;

[0033] Figure 15 This invention relates to the circuit principle of a multi-unit touch display system with air contact. Figure 2 ;

[0034] Figure 16 This invention relates to the circuit principle of a multi-unit touch display system with air contact. Figure 3 ;

[0035] Figures 17-20 The noise results are for products in Comparative Examples 1-4, respectively.

[0036] Figure 21-24 The product noise results using the system and method of the present invention;

[0037] Figure 25-27 The results are for the product semaphores in Comparative Examples 1-3, respectively.

[0038] Figures 28-30 The semaphore results for products using the system and method of the present invention. Detailed Implementation

[0039] The present invention will be further illustrated below with reference to specific embodiments. These embodiments are implemented based on the technical solutions of the present invention, and it should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0040] Example 1

[0041] like Figure 1 As shown, the air-touch multi-unit display system of this embodiment includes a circuit board 1, a bracket 2, a light-blocking layer 3, a film 4, a touch sensing area 5, a lamp cavity 21, an air layer 22, LED beads 23, a sealant layer 8, a front control bracket 7, and a control system.

[0042] like Figure 1The diagram shown is an exploded view of a multi-unit touch display system with air gaps. A circuit board 1, a bracket 2, a light-blocking layer 3, and a film 4 are arranged sequentially. A touch-sensing area 5 is positioned on the circuit board 1 at the location corresponding to the touch display unit. The touch-sensing area 5 on the circuit board 1, the lamp cavity 21 on the bracket 2, and the film 4 form the touch display unit. An air layer 22, formed by the lamp cavity 21 on the bracket 2, passes between the touch point and the touch-sensing area 5. The thickness of the air layer 22 is less than 10mm and greater than 2mm. The display system has multiple adjacent touch display units. The control system receives touch signals from the touch-sensing area 5 and processes the signals. With high sensitivity in identifying touch signals, it eliminates signal interference from adjacent touch display units and accurately identifies the touch signal of the predetermined target touch display unit.

[0043] Preferably, the thickness of the air layer is 3mm-5mm, and the thickness of the film and panel set above the air layer is about 3mm. Therefore, the distance between the touch position and the touch sensing area 5 can achieve a touch distance of 6-8mm (touch distance threshold).

[0044] The height of the lamp cavity 21 is less than or equal to the length and width of the touch sensing area 5, and the interval between adjacent touch sensing areas 5 is greater than or equal to the height of the lamp cavity 21.

[0045] Touch sensing areas 5 are disposed on the circuit board 1 and are correspondingly disposed in the lamp cavity 21 of each touch display unit. In this embodiment, there are multiple lamp cavities 21 arranged in a matrix. The lamp cavity in the middle is surrounded by adjacent lamp cavities and touch sensing areas on all sides. When a touch signal is received, the adjacent touch sensing areas will also receive the touch signal, thereby interfering with the touch sensing area of ​​the predetermined target.

[0046] like Figure 3 As shown, the touch display unit also includes LED beads 23, which are disposed on the circuit board 1 inside the lamp cavity 21. The LED beads 23 are bottom-emitting light sources, and the LED beads 23 are correspondingly disposed with the touch sensing area 5.

[0047] In this invention, the LED beads are set in the touch sensing area. In order to reduce the influence of the LED beads on the sensing signal of the touch sensing area, the number of LED beads set in the touch sensing area 5 should be as small as possible, and the area occupied by the LED beads should be as small as possible.

[0048] Because the size of the touch-sensing area varies, the number of LED beads in each area also varies. In actual use, one, two, or more LEDs can be used to achieve uniform light and meet the required brightness. Figure 8 and 9As shown, touch sensing areas 5 have different numbers of LED beads. For touch sensing areas of the same size, the effect of deploying one LED bead versus multiple LED beads on the touch signal is different. In this implementation, we take deploying one LED bead and three LED beads as examples for comparison and compare the noise values ​​of the two.

[0049] The signal noise of the touch sensing area was tested for single LED beads and three LED beads, and the results are as follows: Figure 10-12 As shown, Figure 10 The noise level for setting a single LED bead in the touch sensing area was 32. Figure 11 The noise level is 66, which is the result of setting three LED beads in the touch sensing area. Figure 12 This is a comparison of noise results when the touch sensing area has one and three LED beads. It can be seen that the fewer the number of LED beads, the lower the noise and the less impact it has on the touch signal.

[0050] To reduce the number of LED chips, minimize their impact on touch signals, and lower noise, while maintaining light intensity and uniformity despite the reduced number of chips, this invention employs specially designed LED chips. In this embodiment, the LED chips are surface-mount LEDs with an average light intensity diffusion angle greater than 170°. In the prior art, the average light intensity diffusion angle of conventional LED chips is less than 120 degrees. This invention specially designs the LED chips to achieve an average light intensity diffusion angle greater than 170°. This reduces the number of LED chips used in the same area of ​​the touch sensing area 5, while achieving uniform light and light intensity that meets design requirements, and satisfying the LED light path requirements within the limited height of the lamp cavity.

[0051] like Figure 13 The figure shows the parameters of the LED beads used in this embodiment. Using LED beads with these parameters results in a large light diffusion range, effectively reducing the number of LED beads required and significantly decreasing touch noise.

[0052] Circuit board 1 is mounted on the back of bracket 2, and a sealant layer 8 is applied to the back of circuit board 1. A waterproof layer is formed by potting the sealant, which is then evenly applied to the back of the circuit board to a thickness of approximately 3mm to 5mm. The waterproof sealant may be polyurethane sealant or silicone, etc. Alternatively, a sealing ring can be used to prevent water from entering the circuit board from appliances near water sources, such as washing machines, and thus affecting its normal operation.

[0053] The thickness of the membrane 4 is 0.1mm~0.5mm. The base film of the membrane 4 can be PET or PC film. A graphic layer is set and printed on the PET or PC film. The membrane can be a colored film to realize the display of icons and text with multiple functions, and can display background patterns with a sense of design.

[0054] The light-blocking layer 3 is a black foam disposed between the film 4 and the bracket 2. The black foam is located on the outer periphery of the lamp cavity 21, blocking the light between adjacent touch display units. The black foam also serves as a filler, filling the gap between the film and the bracket. Furthermore, the foam layer acts as an adhesive medium, bonding the film to the bracket and preventing the film from not adhering tightly to the rigid bracket.

[0055] The display system also includes a panel 6. A display unit consisting of a circuit board 1, a bracket 2, a light-blocking layer 3, and a film 4 is disposed within the panel 6. The panel 6 is mounted on a front control bracket 7. A display window is provided on the panel 6. The display window is made of acrylic, glass, in-mold molding (IMD), or other injection molded parts (using ABS, PC, or ABS+PC materials). The display window can clearly display the content of the screen, and the touch display unit can be controlled by touch through the acrylic or glass panel.

[0056] Example 2

[0057] A method for controlling the sensitivity of a multi-unit touch display system with air contact is provided. This method achieves high touch sensitivity in the aforementioned multi-unit touch display system. The control system uses a high-sensitivity processing chip to process touch signals and accurately determine the touch signals of the target touch display unit.

[0058] like Figure 6 The diagram shown is a schematic of the principle of a finger touching the touch sensing area, where C F It's a finger capacitor, C p It's parasitic capacitance, the sensor capacitance in a capacitive sensing system when there's no finger present. When a finger approaches or touches the sensor, the sensor capacitance changes, which generates a capacitance similar to C. p The other capacitor connected in parallel is called the finger capacitor C. F When a finger is present, the total sensor capacitance Cs is as shown in the following formula:

[0059] Cs=C p +C F ;

[0060] However, when multiple touch sensing areas are arranged in an array, when a finger touches one touch sensing area, adjacent sensing pads will also generate signals, interfering with the intended touch sensing area. This interference is particularly pronounced on adjacent touch sensing areas near the palm. To address this issue, this embodiment employs the following signal processing circuitry and methods to reduce interference signals and noise, and accurately selects the signal for the intended touch sensing area through software processing.

[0061] like Figure 14-16 The diagram shown is a circuit schematic of a touch control unit for a home appliance. Figure 14The circuit diagram shown is for controlling touch signals and LED beads, including a microcontroller and peripheral circuits (button input module, communication interface, power supply and reset circuit, etc.). The microcontroller uses the CY8C4147AZI series microcontroller chip: the microcontroller is the control center of the circuit, and all peripherals are connected to its pins to realize signal input / output, communication, control and other functions.

[0062] The +5V power supply is connected to the VSSA and VSSD pins of the microcontroller via filter capacitors C2 and C3 to power the chip. The +5V is connected to the XRES pin via resistor R10, which, together with capacitor C7, forms a reset circuit to achieve system power-on reset or manual reset.

[0063] The button input module mainly handles the touch control input signals of this invention. Multiple touch control buttons (SW1~SW32) are connected to the GPIO pins (P0.0~P0.7, P2.0~P2.7, etc.) of the microcontroller through resistors. When a touch signal is received, the button is activated, the corresponding pin level changes, and the microcontroller can detect the button input.

[0064] The LED Driver_SDA and LED Driver_SCL pins are connected to an external LED to drive external LED devices. The SPI_MISO, SPI_MOSI, and SPI_SCK pins are used for SPI protocol communication.

[0065] like Figure 7 The diagram shown is a schematic of the signal processing circuit in this embodiment. The total capacitance of the sensor is processed. The signal processing circuit removes the reference and converts it to a differential form.

[0066] The signal processing circuit includes the sensor capacitor C. s The first set of switches swph0 and swph1, the second set of switches swph2 and swph3, and the external capacitor C. MOD1 External capacitor C MOD2 Reference capacitor C ref And a Σ-Δ converter, wherein the Σ-Δ converter includes a comparator and an N-bit counter. Sensor capacitance C s One end is grounded, and the other end is connected to C via switch swph1. MOD1 Connection, simultaneously via swph1 and C MOD1 Grounding; C MOD2 One end is connected to the total sensor capacitance C via swph3. s Connect one end to the ground; C MOD1 One end is connected to the inverting input of the comparator, and the non-inverting input of the converter is connected via C. MOD2 Ground; Reference capacitor C ref It forms a feedback loop with the internal switches of the converter, with reference capacitor C.ref The comparator's non-inverting input is connected via a switch, and its inverting input is also connected via a switch. The comparator's output forms a feedback circuit via a reference capacitor and a switch. A counter is used to count the output pulses. The final output is Raw Count.

[0067] ;

[0068] Where Raw Count represents the raw count, Cs represents the total sensor capacitance, and C ref This represents the reference capacitance, and α is a proportional sign, which can also be understood as a coefficient.

[0069] Figure 7 The working principle of the signal processing circuit shown is as follows:

[0070] External capacitor C MOD1 and external capacitor C MOD2 During initialization, precharge to Vdda / 2.

[0071] Step 1: Turn off swph0, short Cs and Vdda, and charge Cs to Vdda.

[0072] Step 2: Open swph0, close swph1, Cs and C MOD1 Short circuit, C MOD1 The voltage will be boosted, exceeding vdda / 2, at which point C MOD1 Charge from precision capacitor array C ref Release, until C MOD1 Voltage to vdda / 2.

[0073] Step 3: Turn off swph2, short Cs and GND, and reduce the voltage of Cs to 0.

[0074] Step 4: Open swph2, close swph3, Cs and C MOD2 Short circuit, C MOD2 The voltage will be pulled down to less than vdda / 2, at which point the precision capacitor array C ref For C MOD2 Charge until C MOD2 Voltage to vdda / 2.

[0075] The value of Raw Count is used to calculate the time it takes for Raw Count charge to be released to vdda / 2, and C MOD2 The charging time is until vdda / 2. At this point, the only noise source is the comparator error, which eliminates at least two to three noise sources compared to conventional touch mechanisms in existing technologies. Therefore, the current touch sensitivity is higher, the noise is lower, and the anti-interference capability between multi-touch buttons is stronger.

[0076] In addition to the aforementioned hardware circuitry, this invention also employs software algorithms to process the signal, further enhancing signal strength and reducing noise. Currently, touch signals are processed using IIR filtering and median filtering.

[0077] The median filter is a nonlinear filter that takes the three most recent sampled values ​​and calculates their median. The expression is as follows:

[0078] ;

[0079] Where y[i] is the filtered output value at the current time, that is, the result at time i after median filtering. median(...) is the median calculation function, which means taking the median value among the multiple values ​​within the parentheses.

[0080] x[i] is the original sampled value at the current time, that is, the unfiltered data collected at time i.

[0081] x[i-1] is the original sampled value of the previous time step, that is, the unfiltered data collected at time step i-1.

[0082] x[i-2] is the original sampled value of the first two time steps, that is, the unfiltered data collected at time step i-2.

[0083] The mean filter is a finite impulse response filter (without feedback). It uses equal weights, takes the four most recent samples and calculates their average value to eliminate noise generated by power supply, etc. The expression is as follows:

[0084] ;

[0085] Where y[i] is the filtered output value at the current time, that is, the result at time i after mean filtering.

[0086] It is the average coefficient, because the average of the four sample values ​​is to be taken, so the sum is multiplied by 1 / 4.

[0087] x[i] is the original sampled value at the current time, the unfiltered data collected at time i.

[0088] x[i-1] is the original sampled value at the previous time step, and the unfiltered data collected at the (i-1)th time step.

[0089] x[i-2] represents the original sampled values ​​from the first two time steps, and the unfiltered data collected at time step i-2.

[0090] x[i-3] represents the original sampled values ​​from the first three time steps, and the unfiltered data collected at time step i-3.

[0091] A first-order IIR filter is an infinite impulse response filter (with feedback). Its step response is similar to that of an RC low-pass filter. It passes low-frequency signals (such as the response to a finger touch) and eliminates high-frequency noise. The expression is as follows:

[0092] ;

[0093] Where y[i] is the filtered output value at the current time, that is, the result at time i after mean filtering.

[0094] K is a fixed coefficient, and the value of K is fixed at 256;

[0095] N is the filter coefficient (original counting coefficient) of the IIR filter; the smaller the value of N, the lower the noise, but the slower the response speed.

[0096] A first-order IIR filter suppresses high-frequency noise by weighting the current original sample value with the filter output value from the previous moment.

[0097] Hardware IIR filter, suitable for general controls (except for proximity sensing and low-power controls).

[0098] ;

[0099] RawCount is the filtered output value at the current moment (i.e., the original count result at the current moment after hardware IIR filtering).

[0100] iirRCcoef represents the raw count coefficients of the IIR filter, with an effective range of 0 to 8. The smaller the coefficient, the weaker the filtering effect; the larger the coefficient, the longer the response time. Note: A coefficient value of "0" corresponds to no filtering effect.

[0101] 1 / 2 iirRCcoef It is the weighting coefficient of the new sampled value, which controls the proportion of the influence of the current new sampled data on the output.

[0102] RawCount New It is the new raw sample value at the current moment (the latest acquired data of the unfiltered wave).

[0103] (1-1 / 2 iirRCcoef ) is the weighting coefficient of the historical output value, which controls the proportion of the influence of the filtering result of the previous moment on the current output.

[0104] RawCount Previous : The filtered output value of the previous moment (the result after IIR filtering at the previous moment, reflecting the feedback characteristics of IIR).

[0105] In practical applications, median filters, mean filters, first-order IIR filters, and hardware IIR filters are selected based on the actual working conditions and can be used individually or in combination.

[0106] A semaphore (signal level) is the effective signal strength detected by a touch sensor when a touch event occurs. Its core component is the change in capacitance or its converted electrical signal value. The essence of capacitive touch is that when a finger touches the sensor, a coupling capacitance is formed between the human body and the sensor. The sensor detects the change in coupling capacitance (ΔC) and converts it into an electrical signal (such as voltage or count), which is the semaphore.

[0107] The raw signal quantity is directly represented by the sensor's sample count (Raw Count), or the capacitance change ΔC.

[0108] The normalized semaphore is the ratio of the semaphore to the reference value (e.g., ΔC / C0, where C0 is the reference capacitance when there is no touch, avoiding the influence of individual sensor differences).

[0109] Noise is the signal fluctuation (irrelevant interference signal) detected by the sensor when there is no touch. Sources include power supply noise, electromagnetic interference (EMI), changes in ambient humidity / temperature, and fluctuations in sensor parasitic capacitance. Peak-to-peak noise (Peak-Peak) is the difference between the maximum and minimum values ​​of the noise signal over a period of time, directly reflecting the noise amplitude. Root-mean-square noise (RMS) is the root mean square value of the noise signal, reflecting the statistical intensity of the noise and suitable for quantifying random noise. Noise frequency is the frequency of the interfering signal (such as 50Hz power supply noise or MHz-level EMI), used for targeted filtering.

[0110] Sensitivity is the ability of a touch system to respond to the smallest effective touch signal; that is, the smallest amount of touch signal it can detect. Higher sensitivity makes it easier to detect slight touches, such as those made while wearing thin gloves. The minimum detectable signal is the smallest ΔC that the system can stably recognize. The touch distance threshold is the maximum distance (in mm) at which the sensor can detect a touch, such as the maximum distance for air-touch. The response threshold is the threshold amount of signal that triggers a valid touch, indirectly reflecting sensitivity (the lower the threshold, the higher the sensitivity).

[0111] The signal-to-noise ratio (SNR) of the signal and noise determines the upper limit of sensitivity. The essence of sensitivity is whether the signal can be effectively distinguished from the noise. The core indicator is the signal-to-noise ratio (SNR). The higher the SNR, the greater the sensitivity potential.

[0112] like Figure 17-24As shown in Table 1, the noise test results of products manufactured using the system and method of this invention are as follows: the noise level is around 6-7, with an average noise level of 6.5 for multiple products. In contrast, the noise level of existing products that do not use the control method and system of this invention is between 30-48, with an average noise level of 39.5 for multiple comparison products. The final test results show that the noise level of products using the system and control method of this invention is reduced by more than 6 times.

[0113] like Figure 25-30 As shown in Table 2, the signal quantity test results of products manufactured using the system and method of this invention show that most signal quantities are above 2000, with an average signal quantity of 2320 for multiple products. In contrast, the signal quantities of existing products that do not use the control method and system of this invention are only around 200, with an average of 240 for multiple comparison products. The final test results indicate that the signal quantity of products using the system and control method of this invention is more than nine times that of existing products.

[0114] The touch signal is processed by hardware circuitry and further processed by software algorithms. The signal quantity of the new product manufactured using the method of this invention is more than 9 times that of the existing product, and the noise is about 1 / 6 of the existing product, which fully meets the conditions for air touch.

[0115] Table 1 Comparison of Noise Results

[0116]

[0117] Table 2 Semaphore Comparison

[0118]

[0119] This invention reduces the number of LED beads in the touch control area, increases the touch electrode area, thereby improving the signal strength. While reducing the number of LED beads, it also reduces the introduction of noise, achieving two goals at once.

[0120] This invention reduces noise introduction, achieving low noise levels. Furthermore, by optimizing the sensor LED layout and combining effective hardware and software filtering, noise is significantly reduced, providing greater flexibility for sensitivity adjustment. The software sets the touch sensitivity threshold based on the actual measured signal quantity, ultimately achieving a balance between high signal quantity, low noise, and sensitivity control in the entire system.

[0121] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A multi-unit touch display system with air-to-air contact, characterized in that: The circuit board (1), bracket (2), light blocking layer (3) and diaphragm (4) are arranged in sequence. A touch sensing area (5) is set at the position corresponding to the touch display unit on the circuit board (1). The touch sensing area (5) on the circuit board (1), the lamp cavity (21) opened on the bracket (2) and the diaphragm (4) form a touch display unit. An air layer (22) is formed between the touch point and the touch sensing area (5) through the lamp cavity (21) opened on the bracket (2). The thickness of the air layer (22) is greater than 2 mm and less than 10 mm. LED beads are set in the touch sensing area (5). A small number of LED beads with a small area are set in the touch sensing area (5) to reduce the influence of the beads on the sensing signal of the touch sensing area. The LED beads (23) are surface-mount LEDs with an average light intensity diffusion angle greater than 170° to reduce the number of LED beads used in the same area of ​​the touch sensing area (5). The display system is equipped with multiple adjacent touch display units. The height of the lamp cavity (21) of the touch display unit is less than or equal to the length and width of the touch sensing area (5), and the interval between adjacent touch sensing areas (5) is greater than or equal to the height of the lamp cavity (21). The system also includes a control system, which employs a hardware signal processing circuit to process the capacitance of the total sensor. The control system then receives the raw touch sampling signal collected from the touch sensing area and processes the signal using a software algorithm to further improve the signal strength and reduce noise. Specifically, the touch signal is processed through median filtering, mean filtering, and first-order IIR filtering. The hardware signal processing circuit includes the sensor capacitance Cs, two sets of switches, external capacitors CMOD1 and CMOD2, and a reference capacitor C. ref Comparator and N-bit counter; one end of sensor capacitor Cs is grounded, and the other end is connected to CMOD1 through switch swph1, and is also grounded through swph1 and CMOD1; reference capacitor C ref It forms a feedback loop with the comparator and outputs the RawCount raw count value as the original touch sampling signal; The control system receives the touch signal from the touch sensing area (5) and processes the signal to eliminate signal interference from adjacent touch display units, increase the signal quantity, reduce noise, control sensitivity, and identify the touch signal of the predetermined target touch display unit.

2. The air-touch multi-unit display system according to claim 1, characterized in that: The touch sensing area (5) is disposed on the circuit board (1) and is disposed in the lamp cavity (21) of each touch display unit.

3. The air-touch multi-unit display system according to claim 1, characterized in that: The touch display unit also includes LED beads (23), which are disposed on the circuit board (1) inside the lamp cavity (21); the LED beads (23) are bottom-emitting light sources, and the LED beads (23) are disposed corresponding to the touch sensing area (5).

4. The air-touch multi-unit display system according to claim 1, characterized in that: The circuit board (1) is disposed on the back of the bracket (2), and a sealant layer (8) is disposed on the back of the circuit board (1).

5. The air-touch multi-unit display system according to claim 1, characterized in that: The light-blocking layer (3) is a black foam disposed between the diaphragm (4) and the bracket (2). The black foam is located on the outer periphery of the lamp cavity (21) and blocks the light between adjacent touch display units.

6. The air-touch multi-unit display system according to claim 1, characterized in that: The display system also includes a panel (6), and the display unit composed of the circuit board (1), bracket (2), light blocking layer (3) and film (4) is disposed in the panel (6), and the panel (6) is mounted on the front control bracket (7).

7. A method for controlling the sensitivity of multi-unit touch in the absence of air, characterized in that: This method achieves touch sensitivity control of the air-to-ground multi-unit touch display system according to any one of claims 1-6. The control system uses a high-sensitivity, low-noise chip to process touch signals and accurately determines the touch signal of the target touch display unit through software algorithms; it includes the following: (1) By collecting and processing the raw count values ​​of each touch sensing area; (2) Perform median filtering on the original count values: take the three most recent sample values ​​and calculate the median; (3) Perform mean filtering: Take the four most recent sampled values ​​and calculate their average; (4) Perform a first-order IIR low-pass filter to pass the low-frequency signal and eliminate high-frequency noise; (5) The software sets the threshold of touch sensitivity based on the actual measured signal quantity, and finally achieves the coordination of high signal quantity, low noise and sensitivity control in the whole system.

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