Touch position sensor and positioning method

Abstract

The invention provides a touch position sensor and a positioning method, and belongs to the technical field of optical positioning, the touch position sensor comprises an SPAD SoC chip, a VCSEL chip, a packaging substrate, a packaging cover plate, a first optical filter, a second optical filter, a transmitting lens group, a receiving lens group and a lens base; the positions of the two touch position sensors are set; arranging two touch position sensors on two corners of one side of the screen; respectively measuring the distance of the touch position, designing a touch position positioning formula by adopting the cosine law according to the two distance values, and finally accurately calculating the coordinates of the touch position; the touch position sensor has the advantages of being low in cost, small in size, high in universality, suitable for screens of different sizes, capable of completing accurate positioning without changing structural design and bringing in different size parameters of the screens and suitable for application and popularization.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical positioning, and in particular, relates to a touch position sensor and a positioning method. Background Art

[0002] With the rapid development of intelligent terminals, more and more requirements are imposed on display technologies, such as tablet computers, liquid crystal display touch screens, smart phones, intelligent vehicle function interfaces, etc.

[0003] By combining a touch panel or a touch sensor with a display device, an electronic device with both an image display function and an information input function is developed. The touch panel or the touch sensor is an input device that covers the display device and allows a user to input commands by selecting command contents displayed on the screen with an object such as a human hand or a writing pen.

[0004] The Neonode touch sensor module (previously 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 a high scanning frequency, low latency, good touch accuracy, and can be used on any surface; it includes an optical system that combines the emitted IR beams and the receiver's field of view within the same aperture, and the combination of each transmitter-receiver covers a narrow area of the active area; an object present in the active area affects several transmitter-receiver channels, and the reported coordinates are the result of the centroid calculation in these signals;

[0005] Most of the existing touch position sensor solutions adopt the architecture of an infrared transceiver array, which has large technical limitations. For example:

[0006] ① The number of components used in the infrared transceiver array is large, the cost is high, and the size is large; it has a great economic restriction on the pre-production and post-maintenance.

[0007] ② The versatility is poor. For screens of different sizes, sensor modules of different specifications need to be designed, and large-scale production and stockpiling are not possible, which restricts the business development. Summary of the Invention

[0008] In order to solve the above technical problems, the present invention provides a touch position sensor and a positioning method. Through scientific architecture design, the technical deficiencies of large size and non-universality in the prior art are overcome, so that the touch position sensor can be suitable for intelligent terminals at low cost, small size and with greater universality, and can 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 lens holder;

[0010] The TOF chip module includes: an SPAD SoC chip, a VCSEL chip, a packaging substrate, a packaging cover plate, a first filter, and a second filter;

[0011] The SPAD SoC chip: integrates multiple functional modules such as a VCSEL driver, an SPAD photosensitive array module, an 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 by the SPAD SoC chip to emit light; the VCSEL chip emits a circular light spot with a certain divergence angle;

[0013] The packaging substrate serves as the installation and support structure of the TOF chip module;

[0014] There are two light-passing apertures provided above the packaging cover plate, and the packaging cover plate can be buckled with the packaging substrate to form an integral structure;

[0015] The first filter and the second filter are respectively arranged in the two light-passing apertures to form the sealing of the integral structure, and at the same time, they can prevent stray light in other wavelength bands from entering the SPAD SoC chip;

[0016] The transmitting lens group is arranged directly above the first filter, and the receiving lens group is arranged directly above the second filter; the transmitting lens group and the receiving lens group have the same structure;

[0017] The transmitting lens group includes: a positive cylindrical lens and a negative cylindrical lens that are orthogonal to each other, where:

[0018] 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 circular light spot with a certain divergence angle in the y direction by 90°; this action 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; (that is, the emission field of view is shaped 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 1m).

[0019] Similarly, 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 close to overlapping with the laser coverage range of the transmitting lens group, and it is also a flat 90° fan-shaped receiving field of view, that is, the receiving field of view is shaped into about 0° in the x direction and 90° in the y direction. (Because there is a distance between the transmitting lens group and the receiving lens group, this distance is usually small, about 3mm, so the fan-shaped areas of the two are staggered by a distance of 3mm up and down).

[0020] The lens holder is used to fix the transmitting 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 can also use other optical schemes to shape the transmitting field of view and the receiving field of view into a flat fan-shaped area with 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 use a single special-shaped lens to directly achieve the functions of two cylindrical lenses.

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

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

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

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

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

[0030] As an example, the two corners on one side of the screen can be the upper and lower corresponding corners on the same side, or the left and right corresponding corners on the same side.

[0031] Step 2: Measurement of the touch position distance;

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

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

[0034] When there is an object in the detection area and the receiving area, the object will reflect the laser beam hitting it, and a part of the laser beam returns to the TOF chip module; the TOF chip module completes signal processing, flight time calculation, and distance calculation; the distance d of the object from the touch position sensor is designed with the following calculation 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, the two touch position sensors are arranged corresponding to the upper and lower positions, and the distance between them is a. According to the cosine theorem, Formula 2 is designed as follows:

[0038]

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

[0040] x = d2 * tanα; y = d2 * cotα.

[0041] As an example, when the two touch position sensors are arranged corresponding to the left and right positions, and the distance between them is the length b of the screen. According to the cosine theorem, Formula 3 is designed as follows:

[0042]

[0043] At this time, the coordinates of the touch position are:

[0044] x = d1 * cotα; y = d1 * tanα;

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

[0046] In a fourth aspect, the present application discloses a non - transitory computer - readable storage medium. When the instructions in the storage medium are executed by the processor of the electronic device, the electronic device can execute a positioning method for a touch position sensor.

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

[0048] Advantages of the present invention:

[0049] The present invention uses two linear light spot touch position sensors with flat 90° fan-shaped fields of view arranged on one side of the screen to measure the distance to the touch point. Based on the two measured linear distances, the x and y coordinates of the touch point can be accurately calculated.

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

[0051] The present invention has strong versatility and is suitable for screens of different sizes. The touch position sensor module does not need to be changed. It only needs to be arranged at the two corners on one side of the screen, and the screen length and width parameters in the calculation formula are adjusted, so it has strong adaptability.

[0052] A transceiver integrated TOF chip module is adopted, and a lens is added to shape the emission and reception fields of view into flat 90° fans. This design of increasing the emission and reception fields of view ensures that the present invention can detect any position on the rectangular screen. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a partial structural schematic diagram of the TOF chip module of a touch position sensor of the present invention.

[0054] Figure 2 It is an overall structural schematic diagram of a touch position sensor of the present invention in the x direction.

[0055] Figure 3 It is a structural schematic diagram of a touch position sensor of the present invention in the y direction.

[0056] Figure 4 It is a schematic diagram of the principle of the flat 90° fan-shaped emission field of view and the flat 90° fan-shaped reception field of view of a touch position sensor of the present invention.

[0057] Figure 5 It is a schematic diagram of the calculation principle of the design of two touch position sensors on one side of the width side in the positioning method of a touch position sensor of the present invention.

[0058] Figure 6 It is a schematic diagram of the calculation principle of the design of two touch position sensors on one side of the length side in the positioning method of a touch position sensor of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application. Refer to Figures 1 to 6 as shown:

[0060] In a 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; refer to Figure 1 as shown.

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

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

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

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

[0065] Two light passing apertures are provided above the packaging cover plate 104, and the packaging cover plate 104 can be buckled with the packaging substrate 103 to form an integral structure;

[0066] The first filter 105 and the second filter 106 are respectively arranged in the two light passing apertures to form a seal for the integral structure, and at the same time, they can prevent stray light of other wavelength 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 transmitting lens group 201 includes: a positive cylindrical lens and a negative cylindrical lens that are orthogonal to each other, where:

[0069] 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 dot-shaped light spot in the y direction by 90°; this reshapes 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, and the signal area received back is close to coinciding with the laser coverage range of the transmitting lens group, and is also a flat 90° fan-shaped receiving area.

[0071] Refer to Figure 2 As shown, when looking 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; when looking 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. Therefore Figure 2 the positive cylindrical lens cannot be shown, and the principle of the positive cylindrical lens refers to Figure 3 as shown

[0072] The lens holder 203 is used to fix the transmitting 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 its 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 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.

[0076] As an example, the positive cylindrical lens and the negative cylindrical lens can use a single special - shaped lens to directly achieve the functions of two cylindrical lenses.

[0077] As an example, the positive cylindrical lens and the negative cylindrical lens can use a single circular convex lens to collimate the light beam into a point light spot, and then use a Powell prism or a diffractive grating lens to shape the light spot into a line light spot in the architecture scheme.

[0078] In a second aspect, a positioning method for a touch - position sensor includes:

[0079] Step 1: Setting the positions of two touch - position sensors;

[0080] Arrange two touch - position sensors at two corners on one side of the screen;

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

[0082] Step 2: Measuring the touch - position distance;

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

[0084] As an example, after passing through the transmitting lens group 201 and the receiving lens group 202, both the receiving field of view and the transmitting field of view become flat 90° fan-shaped regions covering the screen surface; refer to Figure 4 as shown.

[0085] When there is an object within the detection area and the receiving area, the object will reflect the laser light incident on it, and a part of the laser light returns to the tof chip module; the tof chip module completes signal processing, flight time calculation, and distance calculation; the distance d of the object from the touch position sensor is designed with the following calculation formula:

[0086] d = flight time × speed of light / 2; Formula 1;

[0087] Step three: Touch position calculation;

[0088] Given that the width of the screen is a, that is, the two touch position sensors are arranged corresponding to each other up and down, and the distance between them is a, according to the cosine theorem, Formula 2 is designed as follows:

[0089]

[0090] Then the coordinates of the touch position can be obtained as:

[0091] x = d2 * tanα; y = d2 * cotα. Refer to Figure 5 as shown.

[0092] As an example, when the two touch position sensors are arranged corresponding to each other left and right, and the distance between them is the length b of the screen, according to the cosine theorem, Formula 3 is designed 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 as shown.

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

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

[0098] Fifth aspect, the present application discloses a computer program product. When the instructions in the computer program product are executed by a processor of an electronic device, the electronic device is enabled to execute a positioning method for a touch position sensor.

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

[0100] It should be noted that for method embodiments, for simplicity of description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also 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 text, the term "including", "comprising" 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 expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including that element.

[0102] The embodiments of the present application have been described above in conjunction with the accompanying drawings. However, the present application is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present application, those of ordinary skill in the art can also make many forms without departing from the purpose of the present application and the scope protected by the claims, and all of them belong to the protection scope of the present application.

[0103] Those of ordinary skill 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 implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed 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 processes of the above-described systems, devices and units can refer to the corresponding processes in the foregoing method embodiments and will not be described herein again.

[0105] In the embodiments provided in the present 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 illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, 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 displayed or discussed coupling or direct coupling or communication connection between each other can be through some interfaces. The indirect coupling or communication connection of the devices or units can be in electrical, mechanical or other forms.

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

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

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

[0109] The above are only the 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 its core idea of the present invention, and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A touch position sensor, characterized in that, Including: a TOF chip module, a transmitting lens group, a receiving lens group, and a lens holder; The TOF chip module includes: an SPAD SoC chip, a VCSEL chip, a packaging substrate, a packaging cover plate, a first filter, and a second filter; The SPAD SoC chip: integrates a VCSEL driver, an SPAD photosensitive array module, an 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 the installation support structure of the TOF chip module; There are two light passing apertures above the packaging cover plate, and the packaging cover plate and the packaging substrate are buckled to form an integral structure; The first filter and the second filter are respectively arranged in the two light passing apertures; The transmitting lens group is arranged directly above the first filter, and the receiving lens group is arranged directly above the second filter; The transmitting lens group has the same structure as the receiving lens group. The transmitting 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 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 circular light spot with a certain divergence angle in the y direction by 90°; The transmitting 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 transmitting 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 nearly coincident with 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, characterized in that, The positive cylindrical lens and the negative cylindrical lens can directly achieve the functions of two cylindrical lenses through a special-shaped lens.

5. A touch position sensor according to claim 1, characterized in that, The positive cylindrical lens and the negative cylindrical lens can adopt a structural scheme of collimating the light beam into a point light spot by a circular convex lens and then shaping the light spot into a line light spot by using a Powell prism or a diffractive grating lens.

6. A positioning method for a touch position sensor, characterized in that, Including: Step 1: Position setting of two touch position sensors; Arrange the two touch position sensors at two corners on one side of the screen; Step 2: Measurement of the touch position distance; When a finger or a touch pen touches the screen to form a touch position, the two touch position sensors respectively measure two distances d1 and d2; The d1 and d2 are the straight-line distances from the touch position to the two touch position sensors; Step 3: Calculation of the touch position; It is known that the width of the screen is a, that is, the two touch position sensors are arranged corresponding to each other up and down, and the distance between them is a. According to the cosine theorem, formula 2 is designed as follows: Then the coordinates of the touch position are obtained as: x = d2 * tanα; y = d2 * cotα.

7. A positioning method for a touch position sensor according to claim 6, characterized in that, The two corners on one side of the screen refer to: the two upper and lower corresponding corners or the two left and right corresponding corners on the same side.

8. A positioning method of a touch position sensor according to claim 6, characterized in that, When there is an object in the detection area and the receiving area, the object will reflect the laser beam hitting it, and a part of the laser beam returns to the TOF chip module; the TOF chip module completes signal processing, flight time calculation, and distance calculation. The distance d from the object to the touch position sensor is designed with the following calculation formula: d = flight time × speed of light / 2; Formula 1.

9. A positioning method for a touch position sensor according to claim 6, characterized in that, When two touch position sensors are arranged corresponding to each other left and right, and the distance between them is the length b of the screen, Formula 3 is designed according to the cosine theorem as follows: At this time, the coordinates of the touch position 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 a positioning method of a touch position sensor according to any one of claims 6-9.

Images