Touch position sensor and positioning method

Abstract

The application provides a touch position sensor and a positioning method, and belongs to the technical field of optical positioning, and comprises a SPAD SoC chip, a VCSEL chip, a packaging substrate, a packaging cover plate, a first filter, a second filter, a transmitting lens group, a receiving lens group and a mirror seat; the positions of two touch position sensors are set; the two touch position sensors are arranged on two corners of one side of a screen; the distances of touch positions are measured respectively; according to two distance values, a touch position positioning formula is designed by using a cosine theorem; and finally, touch position coordinates are accurately calculated; the touch position sensor designed by the application has the advantages of low cost, small size, strong universality, suitability for screens of different sizes, no need to change the structure design, and the ability to complete accurate positioning by bringing different size parameters of the screen, and is suitable for popularization and application.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optical positioning technology, in particular to a touch position sensor and a positioning method. BACKGROUND

[0002] With the rapid development of intelligent terminals, the requirements for display technology are increasing, such as tablet computers, liquid crystal display touch screens, smart phones, smart car function interfaces, etc.

[0003] By combining touch panels or touch sensors with display devices to develop electronic devices with both image display functions and information input functions, touch panels or touch sensors are input devices that are overlaid on display devices and allow user commands to be input by selecting instruction content displayed on the screen with a person's hand or a writing pen or the like.

[0004] The Neonode touch sensor module (formerly known as ZFORCE AIR) in the prior art is a laser touch sensor module that can be integrated and used in various applications; it has high scanning frequency, low delay, good touch accuracy, and can be used on any surface; it contains an optical system that combines IR light beams and receiver fields of view in the same aperture, and each transmitter-receiver combination covers a narrow area of the active area; the presence of an object in the active area will affect several transmitter-receiver channels, and the reported coordinates are the result of the calculation of the center of gravity of these signals;

[0005] Most existing touch position sensor solutions use infrared transceiver array architecture, which has great technical limitations, for example:

[0006] ① The number of components used by the infrared transceiver array is large, the cost is high, and the size is large; it has a great economic constraint on the early production and maintenance.

[0007] ② Poor versatility, different sizes of screens require different specifications of sensor modules, which cannot be mass-produced and stored, restricting business development. SUMMARY

[0008] In order to solve the above technical problems, the present application provides a touch position sensor and a positioning method, which overcomes the technical deficiencies of the prior art such as large size and lack of versatility through scientific architecture design, so that the touch position sensor can be low-cost, small-size, more versatile and suitable for intelligent terminals, and easily adapt to screens of various specifications.

[0009] In a first aspect, a touch position sensor includes: a tof chip module, a transmitting lens group, a receiving lens group, and a mirror seat.

[0010] The tof chip module comprises a SPAD SoC chip, a VCSEL chip, a packaging substrate, a packaging cover plate, a first optical filter and a second optical filter.

[0011] The SPAD SoC chip is integrated with multiple functional modules, such as a VCSEL drive, a SPAD photosensitive array module, a SPAD signal processing module (TDC & histogram), a ranging data processing module, a clock module, a power management module and a logic control module.

[0012] The VCSEL chip is driven to emit light by the SPAD SoC chip, and the VCSEL chip emits a circular light spot with a certain divergence angle.

[0013] The packaging substrate serves as a mounting support structure of the tof chip module.

[0014] The packaging cover plate is provided above with two light transmission apertures, and the packaging cover plate can be buckled with the packaging substrate to form an integrated structure.

[0015] The first optical filter and the second optical filter are respectively arranged in the two light transmission apertures to form a seal for the integrated structure and to prevent other wavebands of stray light from entering the SPAD SoC chip.

[0016] The emission lens group is arranged directly above the first optical filter, and the receiving lens group is arranged directly above the second optical filter; the emission lens group and the receiving lens group are structurally identical.

[0017] The emission lens group comprises mutually orthogonal positive cylindrical lenses and negative cylindrical lenses, wherein:

[0018] The positive cylindrical lenses are used to compress the circular light spot with a certain divergence angle in the x direction into parallel light; the negative cylindrical lenses are used to expand the circular light spot with a certain divergence angle in the y direction into 90°; in this way, the circular light spot with a certain divergence angle emitted by the VCSEL chip is reshaped into a flat 90° fan-shaped emission field of view; (that is, the emission field of view is reshaped into about 0° in the x direction and 90° in the y direction; the radius of this fan-shaped area is the maximum measurement distance of the touch sensor, which can usually reach 1 m).

[0019] Similarly, the receiving lens group comprises mutually orthogonal positive cylindrical lenses and negative cylindrical lenses; the signal receiving area of the receiving lens group is close to the laser coverage range of the emission lens group, and is also a flat 90° fan-shaped receiving field of view, that is, the receiving field of view is reshaped into about 0° in the x direction and 90° in the y direction. (Because there is a distance between the emission lens group and the receiving lens group, the distance is usually small, about 3 mm, so the fan-shaped areas of the two are staggered by a distance of 3 mm.)

[0020] The mirror seat is used to fix the emission lens group and the receiving lens group.

[0021] As an example, the positive cylindrical lens is a convex cylindrical lens, and its cylindrical direction is parallel to the long side direction of the TOF chip module;

[0022] The negative cylindrical lens is a concave cylindrical lens, and its cylindrical direction is parallel to the short side direction of the TOF chip module; the long side direction of the TOF chip module is the y direction, and the short side direction is the x direction.

[0023] As an example, the transmitting lens group and the receiving lens group may also use other optical solutions to shape the transmitting field of view and the receiving field of view into a flat fan-shaped area of ​​approximately 0° in the x direction and 90° in the y direction.

[0024] As an example, the positive cylindrical lens and the negative cylindrical lens can directly realize the functions of two cylindrical lenses by using a single special-shaped lens.

[0025] As an example, the positive cylindrical lens and the negative cylindrical lens can use a circular convex lens to collimate the light beam into a point light spot, and then use a Powell prism or a diffraction grating lens to shape the light spot into a line light spot.

[0026] As an example, the initial emission field of view emitted by the VCSEL chip and the initial receiving field of view of the SPAD SoC chip are both 25° cones.

[0027] In a second aspect, a method for positioning a touch position sensor includes:

[0028] Step 1: Position setting of two touch position sensors;

[0029] Arrange two touch position sensors at two corners of one side of the screen;

[0030] As an example, the two corners on one side of the screen may be two corresponding corners at the top and bottom of the same side, or two corresponding corners at the left and right of the same side.

[0031] Step 2: Touch position distance measurement;

[0032] When a finger or a touch pen touches the screen to form a touch position, the two touch position sensors measure two distances d1 and d2 respectively; d1 and d2 are the straight-line distances between the touch position and the two touch position sensors;

[0033] As an example, after passing through the transmitting lens group and the receiving lens group, the receiving field of view and the transmitting field of view are transformed into flat 90° fan-shaped areas covering the screen surface;

[0034] When an object is within the detection and receiving areas, the object will reflect the laser light hitting it, and part of the laser light will return to the TOF chip module. The TOF chip module completes signal processing, flight time calculation, and distance calculation. The distance D between the object and the touch position sensor is calculated using the following formula:

[0035] d = flight time × speed of light / 2; Formula 1;

[0036] Step 3: Touch position calculation;

[0037] Given that the width of the screen is a, that is, two touch position sensors are set correspondingly at the top and bottom, and the distance between them is a, the formula 2 is designed according to the law of cosines as follows:

[0038]

[0039] The coordinates of the touch position can be obtained as:

[0040] x=d2*tanα; y=d2*cotα.

[0041] As an example, when two touch position sensors are set correspondingly on the left and right, and the distance between them is the length b of the screen, Formula 3 is designed according to the law of cosines as follows:

[0042]

[0043] The coordinates of the touch position at this time are:

[0044] x=d1*cotα; y=d1*tanα;

[0045] In a third aspect, the present application shows an electronic device, which includes: a processor; a memory for storing processor-executable instructions; wherein the processor is configured to execute a positioning method for a touch position sensor.

[0046] In a fourth aspect, the present application shows a non-transitory computer-readable storage medium. When instructions in the storage medium are executed by a processor of an electronic device, the electronic device is enabled to perform a positioning method for a touch position sensor.

[0047] In a fifth aspect, the present application illustrates a computer program product. When instructions in the computer program product are executed by a processor of an electronic device, the electronic device is enabled to execute a method for positioning a touch position sensor.

[0048] Beneficial effects of the present invention:

[0049] The application adopts two flat 90° sector field linear spot touch position sensors arranged on one side of the screen to measure the distance of the touch point, and the x and y coordinates of the touch point can be accurately calculated according to the measured two linear distances.

[0050] The touch position sensor designed by the application has the advantages of low cost and small size, and is suitable for popularization and application.

[0051] The application has strong universality, is suitable for screens of different sizes, and the touch position sensor module does not need to be changed, only the screen length and width parameters in the calculation formula need to be adjusted, and the adaptability is strong.

[0052] The tof chip module with the functions of receiving and transmitting is used, and a lens is added to shape the emission and receiving field into a flat 90° sector, and the design of increasing the emission field and the receiving field ensures that the application can detect any position of the rectangular screen. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 It is a tof chip module part structure diagram of the touch position sensor of the application.

[0054] Figure 2 It is an x direction overall structure diagram of the touch position sensor of the application.

[0055] Figure 3 It is a y direction structure diagram of the touch position sensor of the application.

[0056] Figure 4 It is a flat 90° sector emission field and a flat 90° sector receiving field principle diagram of the touch position sensor of the application.

[0057] Figure 5 It is a calculation principle diagram of the positioning method of the touch position sensor of the application, in which two touch position sensors are designed on one side of the width side.

[0058] Figure 6 It is a calculation principle diagram of the positioning method of the touch position sensor of the application, in which two touch position sensors are designed on one side of the length side. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are some of the embodiments of the application, not all the embodiments of the application; based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application, and refer to Figures 1 to 6 the drawings shown:

[0060] In the first aspect, a touch position sensor includes: a TOF chip module, a transmitting lens group 201, a receiving lens group 202 and a lens holder 203; Figure 1 shown.

[0061] The TOF chip module includes: a SPAD SoC chip 101, a VCSEL chip 102, a packaging substrate 103, a packaging cover 104, a first filter 105, and a second filter 106;

[0062] The SPAD SoC chip 101 integrates multiple functional modules such as VCSEL driver, SPAD photosensitive array module, SPAD signal processing module (TDC & histogram), ranging data processing module, clock module, power management module, and logic control module;

[0063] The VCSEL chip 102 is driven by the SPAD SoC chip 101 to emit light; the VCSEL chip 102 emits a circular light spot with a certain divergence angle;

[0064] The packaging substrate 103 serves as a mounting support structure for the TOF chip module;

[0065] Two light-transmitting apertures are provided above the package cover plate 104, and the package cover plate 104 can be buckled with the package substrate 103 to form an integrated structure;

[0066] The first filter 105 and the second filter 106 are respectively arranged in the two light-clearing apertures to form a seal for the integrated structure, and at the same time can prevent stray light of other bands from entering the SPAD SoC chip 101;

[0067] The transmitting lens group 201 is arranged directly above the first filter 105, and the receiving lens group 202 is arranged directly above the second filter 106; the transmitting lens group 201 and the receiving lens group 202 have the same structure;

[0068] The emitting lens group 201 includes a positive cylindrical lens and a negative cylindrical lens that are orthogonal to each other, wherein:

[0069] The positive cylindrical lens is used to compress the circular light spot with a certain divergence angle in the x-direction into parallel light; the negative cylindrical lens is used to expand the point-shaped light spot in the y-direction to 90°. This will shape the circular light spot with a certain divergence angle emitted by the VCSEL chip 102 into a flat 90° fan-shaped detection area.

[0070] Similarly, the receiving lens group 202 includes a positive cylindrical lens and a negative cylindrical lens that are orthogonal to each other. The area where the returned signal is received nearly overlaps with the laser coverage range of the transmitting lens group, and is also a flat 90° fan-shaped receiving area.

[0071] Referring to Figure 2 As shown in the figure, from the x direction, only the shape of the concave lens can be seen, and the cross section of the convex lens looks like a rectangle; from the y direction, only the shape of the convex lens can be seen, and the cross section of the concave lens looks like a rectangle, so Figure 2 A positive cylindrical lens cannot be displayed, and the principle of the positive cylindrical lens is shown in the figure. Figure 3

[0072] The mirror seat 203 is used to fix the emitting lens group 201 and the receiving lens group 202;

[0073] The tof chip module is fixed on the PCB 204;

[0074] As an example, the positive cylindrical lens is a convex cylindrical lens, and the cylindrical direction is parallel to the long side direction of the tof chip module;

[0075] The negative cylindrical lens is a concave cylindrical lens, and the cylindrical direction is parallel to the short side direction of the tof chip module; the long side direction of the tof chip module is the y direction, and the short side direction is the x direction.

[0076] As an example, the positive cylindrical lens and the negative cylindrical lens can use a piece of special-shaped lens to directly realize the function of two pieces of cylindrical lenses.

[0077] As an example, the positive cylindrical lens and the negative cylindrical lens can use a piece of circular convex lens to collimate the light beam into a point spot, and then use a Powell prism or a diffraction grating lens to form a line spot.

[0078] In a second aspect, a positioning method of a touch position sensor comprises:

[0079] Step 1: Position setting of two touch position sensors;

[0080] The two touch position sensors are arranged on two corners of one side of the screen;

[0081] As an example, the two corners of one side of the screen can be two corresponding corners on the upper and lower sides of the same side, or two corresponding corners on the left and right sides of the same side.

[0082] Step 2: Touch position distance measurement;

[0083] When a finger or a touch pen touches the screen to form a touch position, two touch position sensors respectively measure two distances d1 and d2; the d1 and d2 are the straight line distances of the touch position from the two touch position sensors;

[0084] ​As an example, after the transmitting lens group 201 and the receiving lens group 202, the receiving field of view and the transmitting field of view are both changed into a flat 90° sector area covering the screen surface; refer to Figure 4

[0085] When there is an object in the detection area and the receiving area, the object will reflect the laser hitting it, part of which returns to the tof chip module; the tof chip module completes signal processing, time of flight calculation and distance calculation; the distance d of the object from the touch position sensor is designed as follows:

[0086] d = time of flight x light speed / 2; formula 1;

[0087] Step three: touch position calculation;

[0088] It is known that the width of the screen is a, that is, the two touch position sensors are set up correspondingly above and below, and the distance between them is a, and formula 2 is designed according to the cosine law as follows:

[0089]

[0090] Then the coordinates of the touch position are:

[0091] x = d2*tanα; y = d2*cotα; refer to Figure 5

[0092] As an example, when the two touch position sensors are set up correspondingly left and right, the distance between them is the length b of the screen, and formula 3 is designed according to the cosine law as follows:

[0093]

[0094] At this time, the coordinates of the touch position are:

[0095] x = d1*cotα; y = d1*tanα; refer to Figure 6

[0096] In a third aspect, the present application shows an electronic device, which comprises: a processor; a memory for storing processor executable instructions; wherein the processor is configured to execute a positioning method of a touch position sensor.

[0097] In a fourth aspect, the present application shows a non-transitory computer readable storage medium, when the instructions in the storage medium are executed by the processor of an electronic device, the electronic device can execute a positioning method of a touch position sensor.

[0098] ​​​In a fifth aspect, the present application shows a computer program product, when instructions in the computer program product are executed by a processor of an electronic device, the electronic device is enabled to perform a positioning method of a touch position sensor.

[0099] As an example, the touch position sensor is connected to a host system through a standard connector and communicates through a standard I2C or USB interface.

[0100] It should be noted that, for the method embodiments, for the convenience and conciseness of description, they are all described as a combination of a series of actions, but those skilled in the art should know that the present application is not limited by the order of the actions described, because according to the present application, certain steps can be performed in other order or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification are all optional embodiments, and the actions involved are not necessarily essential to the present application.

[0101] It should be noted that, in this document, the term "comprising" or "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or device comprising the element.

[0102] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative and not limiting, and those skilled in the art can make many forms under the inspiration of the present application without departing from the scope of the present application and the scope of protection of the claims.

[0103] Those skilled in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in the embodiments of the present application can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0104] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0105] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0106] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0107] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0108] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

[0109] The above are only preferred embodiments of the present invention. It should be understood that the description of the above embodiments is only used to help understand the method and core ideas of the present invention, and is not used to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, etc. made within the ideas and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A touch position sensor, characterized in that: include: Tof chip module, transmitting lens group, receiving lens group and lens holder; The TOF chip module includes: a SPAD SoC chip, a VCSEL chip, a packaging substrate, a packaging cover, a first filter, and a second filter; the SPAD SoC chip integrates a VCSEL driver, a SPAD photosensitive array module, a SPAD signal processing module, a ranging data processing module, a clock module, a power management module, and a logic control module; the VCSEL chip is driven by the SPAD SoC chip to emit a circular light spot with a certain divergence angle; The packaging substrate serves as a mounting support structure for the TOF chip module; two light-clearing apertures are provided above the packaging cover plate, and the packaging cover plate and the packaging substrate are buckled to form an integrated structure; the first filter and the second filter are respectively provided in the two light-clearing apertures; The emitting lens group is arranged directly above the first filter, and the receiving lens group is arranged directly above the second filter; the emitting lens group has the same structure as the transmitting lens group, and the emitting lens group includes: a positive cylindrical lens and a negative cylindrical lens that are orthogonal to each other, the positive cylindrical lens is used to compress a circular light spot with a certain divergence angle in the x direction into parallel light; the negative cylindrical lens is used to expand a circular light spot with a certain divergence angle in the y direction to 90°; the emitting lens group shapes the circular light spot with a certain divergence angle emitted by the VCSEL chip into a flat 90° fan-shaped emission field of view; the lens holder is used to fix the emitting lens group and the receiving lens group.

2. The touch position sensor according to claim 1, wherein: The receiving lens group includes: a positive cylindrical lens and a negative cylindrical lens that are orthogonal to each other. The signal area received by the receiving lens group is almost the same as the laser coverage range of the transmitting lens group, and is also a flat 90° fan-shaped receiving field of view. The tof chip module is fixed on the PCB.

3. The touch position sensor according to claim 1, wherein: The positive cylindrical lens is a convex cylindrical lens, and its cylindrical direction is parallel to the long side direction of the tof chip module; the negative cylindrical lens is a concave cylindrical lens, and its cylindrical direction is parallel to the short side direction of the tof chip module.

4. The touch position sensor according to claim 1, wherein: The positive cylindrical lens and the negative cylindrical lens can directly realize the functions of two cylindrical lenses through a single special-shaped lens.

5. The touch position sensor according to claim 1, wherein: The positive cylindrical lens and the negative cylindrical lens can use a circular convex lens to collimate the light beam into a point light spot, and then use a Powell prism or a diffraction grating lens to shape the light spot into a line light spot.

6. A method for positioning a touch position sensor according to claim 1, characterized in that: include: Step 1: Position setting of two touch position sensors; Arrange two touch position sensors at two corners of one side of the screen; Step 2: Touch position distance measurement; When a finger or a touch pen touches the screen to form a touch position, the two touch position sensors measure two distances d1 and d2 respectively; d1 and d2 are the straight-line distances between the touch position and the two touch position sensors; Step 3: Touch position calculation; Given that the width of the screen is a, that is, two touch position sensors are set correspondingly at the top and bottom, and the distance between them is a, the formula 2 is designed according to the law of cosines as follows: The coordinates of the touch position are: x=d2*tana;y=d2*cotα。 7. The positioning method according to claim 6, characterized in that: The two corners on one side of the screen refer to: two corresponding corners on the top and bottom of the same side or two corresponding corners on the left and right of the same side.

8. The positioning method according to claim 6, characterized in that: When an object is within the detection and receiving areas, the object will reflect the laser light hitting it, and part of the laser light will return to the TOF chip module; the TOF chip module completes signal processing, flight time calculation, and distance calculation; The distance d between the object and the touch position sensor is calculated using the following formula: d = flight time × speed of light / 2; Formula 1.

9. The positioning method according to claim 6, characterized in that: When two touch position sensors are set correspondingly on the left and right, and the distance between them is the length b of the screen, the formula 3 is designed according to the cosine theorem as follows: The coordinates of the touch position at this time are: x=d1*cotα; y=d1*tanα.

10. An electronic device, characterized in that: The electronic device includes: a processor and a memory for storing processor-executable instructions; wherein the processor is configured to execute the method for positioning a touch position sensor according to any one of claims 6 to 9.

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