Single transducer ultrasonic touch screen based on spatial scattering coded structured boundary

Abstract

The present invention provides a single-transducer ultrasonic touch screen based on spatial scattering coding structured boundaries, which relates to active elastic wave target positioning technology, including: a structured boundary, a touch screen, and a piezoelectric transducer; the touch screen is arranged in the structured boundary; the piezoelectric transducer is arranged on the structured boundary, and is used to excite ultrasonic signals on the touch screen and receive echo signals; the structured boundary is composed of scatterer units, and is used to perform spatial scattering coding on ultrasonic waves. The present invention can accurately recognize input characters by using a single piezoelectric transducer, does not require multi-channel data acquisition, is helpful to simplify the system, and is helpful to reduce costs and power consumption.

Description

Technical Field

[0001] The invention relates to an active elastic wave target positioning technology, in particular to a single-transducer ultrasonic touch screen based on a spatial scattering coding structured boundary. Background Art

[0002] Using active acoustic and elastic waves to locate and image objects is an important technology that has wide applications in structural health testing, medical imaging, human-computer interaction, and other fields. Existing technologies mainly use transducer arrays to emit ultrasonic pulses and receive echoes from objects to achieve target positioning and imaging. The time delay between wave transmission and observation contains the location information of the object, and combined with signal processing algorithms, the location of the target object can be identified.

[0003] The existing Chinese patent with publication number CN111722750A discloses a novel touch screen implementation method using an ultrasonic transducer coating, which covers the display screen and is a high-density polymer-based MEMS ultrasonic transducer array, to accurately locate the touch points on the screen surface.

[0004] The inventor believes that the existing ultrasonic positioning technology relies on a large number of sensors, the hardware system is complex, and the cost and power consumption are high. The positioning and imaging performance is also closely related to the layout of the transducer, which limits its application in narrow areas. In addition, the existing ultrasonic touch screen technology relies on two or more transducers and mainly uses a time delay estimation algorithm to locate the touch point. This method still has room for improvement in terms of cost and power consumption control, spatial resolution and recognition accuracy. Summary of the invention

[0005] In view of the defects in the prior art, an object of the present invention is to provide a single-transducer ultrasonic touch screen based on spatial scattering coded structured boundaries.

[0006] A single-transducer ultrasonic touch screen based on spatial scattering coding structured boundary provided by the present invention comprises: a structured boundary, a touch screen, and a piezoelectric transducer; the touch screen is arranged within the structured boundary; the piezoelectric transducer is arranged on the structured boundary, and is used to excite ultrasonic signals on the touch screen and receive echo signals; the structured boundary is composed of scatterer units, and is used to perform spatial scattering coding on ultrasonic waves.

[0007] Preferably, it further comprises a signal generator and a power amplifier; the signal generator is used to generate an excitation signal; the power amplifier is used to amplify the excitation signal.

[0008] Preferably, the excitation signal comprises a plurality of Gaussian pulse modulation signals with different center frequencies.

[0009] Preferably, the scatterer units include scatterer units with random structural parameters and disordered spatial distribution.

[0010] Preferably, the scatterer unit comprises a columnar structure, a hole structure, a grating structure, and a curled structure.

[0011] Preferably, the structured boundary is integrated with the touch screen after processing.

[0012] Preferably, the structured boundary and the touch screen are manufactured in an integrated manner.

[0013] Preferably, the manufacturing method of the structured boundary includes 3D printing, laser processing, and mechanical processing.

[0014] Preferably, the material of the structured boundary includes glass, metal, or plastic.

[0015] Preferably, the touch screen is made of glass, metal or plastic.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention can accurately recognize input characters by using a single piezoelectric transducer, does not require multi-channel data acquisition, helps simplify the system, helps reduce costs, and helps reduce power consumption.

[0018] 2. The present invention performs spatial scattering encoding of ultrasonic waves through a structured boundary formed by scatterer units, which helps to accurately identify the touch position and improve the accuracy.

[0019] 3. The present invention helps to improve accuracy and reduce costs through the coordinated use of a signal generator and a power amplifier. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0021] Figure 1 This is a schematic diagram of the overall structure of a single-transducer ultrasonic touch screen based on spatial scattering coded structured boundaries, which is mainly embodied in the present invention;

[0022] Figure 2 This is an experimental result of the present invention mainly embodies this embodiment.

[0023] As shown in the figure:

[0024] Structured Boundary 1 Touch Screen 2 Piezoelectric Transducer 3 DETAILED DESCRIPTION

[0025] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0026] like Figure 1 As shown, a single-transducer ultrasonic touch screen based on spatial scattering coding structured boundary provided according to the present invention includes: a structured boundary 1, a touch screen 2, and a piezoelectric transducer 3; the touch screen 2 is arranged in the structured boundary 1; the piezoelectric transducer 3 is arranged on the structured boundary 1, and is used to excite ultrasonic signals on the touch screen 2 and receive echo signals; the structured boundary 1 is composed of scatterer units, and is used to perform spatial scattering coding on ultrasonic waves.

[0027] The scattering of elastic waves in the touch screen 2 is spatially encoded by the structured boundary 1, and a single piezoelectric transducer 3 is used in combination with a computational perception reconstruction algorithm to realize the recognition of the finger touch position. The present invention realizes accurate recognition of the finger touch position by only one piezoelectric transducer 3, and does not require multi-channel acquisition. In addition to the piezoelectric transducer 3, the touch screen 2 of the present invention does not contain any electronic components, and has the advantages of simple system, low cost, low power consumption, etc.

[0028] The present invention also includes a signal generator and a power amplifier; the signal generator is used to generate an excitation signal; the power amplifier is used to amplify the excitation signal. The excitation signal includes a plurality of Gaussian pulse modulation signals with different center frequencies. The Gaussian pulse modulation signals with different center frequencies are combined into an excitation signal, the signal generator is used to generate the excitation signal, and the power amplifier is used to amplify the excitation signal to drive the piezoelectric transducer 3 to excite ultrasonic waves in the touch screen 2.

[0029] The structured boundary 1 is composed of scatterer units, which are used to perform spatial scattering encoding on ultrasound. The scatterer units include scatterer units with random structural parameters and disordered spatial distribution. The scatterer units include columnar structures, hole structures, grating structures, and curled structures. The structure, spatial distribution, size, and number of scatterer units in the structured boundary 1 will affect the spatial encoding characteristics of ultrasound.

[0030] The manufacturing method of the structured boundary 1 includes 3D printing, laser processing, and mechanical processing. The material of the structured boundary 1 includes glass, metal, and plastic. The material of the touch screen 2 includes glass, metal, and plastic. The structured boundary 1 can be independently processed and then integrated with the touch screen 2. The structured boundary 1 can also be processed and manufactured in an integrated manner with the touch screen 2.

[0031] Before using the present invention, the position of the touch point is first calibrated. Multiple Gaussian pulse modulation signals with different center frequencies are used as excitation signals. One emission and reception of a pulse excitation is regarded as one measurement of the target, and the emission and reception of multiple pulse excitations are regarded as multiple measurements of the target. A signal generator is used to generate an excitation signal, and a power amplifier is used to amplify the excitation signal to drive the piezoelectric transducer 3 to excite ultrasonic waves in the touch screen 2. The reference signal received by a single piezoelectric transducer 3 when there is no finger touch is collected, and the reference signal is collected multiple times and averaged to obtain a reference signal. The fingers are placed on the specified touch points in turn, and the finger touch echo signal received by a single piezoelectric transducer 3 is collected. The difference signal is obtained by subtracting the reference signal from the echo signal, and the difference signal is used to construct an observation matrix that meets the computational perception reconstruction conditions to achieve calibration of the touch point position.

[0032] The steps of using the present invention to identify touch points are as follows:

[0033] S1: a single piezoelectric transducer 3 continuously transmits an excitation signal;

[0034] S2: Touch a certain position with a finger and collect the echo signal received by the piezoelectric transducer 3;

[0035] S3: pre-processing the echo signal;

[0036] S4: Use computational perception reconstruction algorithm to identify the location of touch points.

[0037] like Figure 2 In the experimental result of the present embodiment shown, the actual position touched by the finger on the touch screen 2 is the character “J”, and the recognition result of the touch point position is the character “J”.

[0038] Compared with the prior art, the present invention does not require any electronic components except a single piezoelectric transducer 3, and reduces the number of required piezoelectric transducers 3 to only one. It can accurately recognize input characters and does not require multi-channel data acquisition. It has the advantages of simple system, low cost and low power consumption.

[0039] How it works

[0040] Gaussian pulse modulation signals with different center frequencies are combined into an excitation signal, a signal generator is used to generate the excitation signal, and a power amplifier is used to amplify the excitation signal to drive the piezoelectric transducer 3 to excite ultrasonic waves in the touch screen 2. The scattering of elastic waves in the touch screen 2 is spatially encoded by the structured boundary 1, and the finger touch position is recognized by a single piezoelectric transducer 3 in combination with a computational perception reconstruction algorithm.

[0041] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0042] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A single transducer ultrasonic touch screen based on spatial scattering coded structured boundaries, characterized in that: include: Structured boundary (1), touch screen (2), piezoelectric transducer (3); The touch screen (2) is arranged within the structured boundary (1); The piezoelectric transducer (3) is arranged on the structured boundary (1) and is used to excite an ultrasonic signal on the touch screen (2) and receive an echo signal; The structured boundary (1) is composed of scatterer units and is used to perform spatial scattering encoding on ultrasonic waves; Also included are a signal generator and a power amplifier; The signal generator is used to generate an excitation signal; The power amplifier is used to amplify the excitation signal; The scatterer units include scatterer units with random structural parameters and disordered spatial distribution; The structured boundary (1) and the touch screen (2) are manufactured in an integrated manner.

2. The single-transducer ultrasonic touch screen based on spatial scattering coded structured boundary according to claim 1, characterized in that: The excitation signal includes a plurality of Gaussian pulse modulation signals with different center frequencies.

3. The single-transducer ultrasonic touch screen based on spatial scattering coded structured boundary according to claim 1, characterized in that: The scatterer unit comprises a columnar structure, a hole structure, a grid structure and a curled structure.

4. The single-transducer ultrasonic touch screen based on spatial scattering coded structured boundary according to claim 1, characterized in that: The structured boundary (1) is integrated with the touch screen (2) after processing.

5. The single-transducer ultrasonic touch screen based on spatial scattering coded structured boundary according to claim 1, characterized in that: The manufacturing method of the structured boundary (1) includes 3D printing, laser processing, and mechanical processing.

6. The single-transducer ultrasonic touch screen based on spatial scattering coded structured boundary according to claim 1, characterized in that: The material of the structured boundary (1) includes glass, metal, and plastic.

7. The single-transducer ultrasonic touch screen based on spatial scattering coded structured boundary according to claim 1, characterized in that: The material of the touch screen (2) includes glass, metal and plastic.

Images