Capacitive touch screen

Abstract

The utility model discloses a capacitive touch screen which comprises a touch panel, and the touch panel further comprises an upper electrode layer, an insulating layer, a lower electrode layer and a controller. The controller is connected with the upper electrode layer and the lower electrode layer and is used for circularly reading the capacitance value of each electrode plate; the electric heating wire further comprises at least one temperature sensor, and the at least one temperature sensor is installed on the insulating layer. If the object is a hand, the temperature detected by the temperature sensor is high, the circuit board determines the touch position according to the fact that the temperature at the capacitance value change position exceeds a specified threshold value, and then the corresponding function of the touch position can be executed; on the contrary, if the object is a water drop, the temperature detected by the temperature sensor is low, although the circuit board can sense the change of the capacitance value, the temperature is low, and the corresponding function of the touch position is not executed at the moment. Therefore, when water drops drop on the screen, the capacitive touch screen does not play a point contact role, and the user experience is improved.

Description

Technical Field

[0001] This application relates to the field of displays, and more specifically to a capacitive touchscreen. Background Technology

[0002] The currently popular capacitive touch screens mainly consist of an upper electrode layer, a middle insulating layer, and a lower electrode layer. The upper electrode layer and the lower electrode layer are each composed of several diamond-shaped electrode arrays, and the diamonds of the upper electrode layer and the lower electrode layer are arranged in a crisscross pattern. When powered on, a stable electric field is formed between the upper electrode layer and the lower electrode. If a finger touches the screen, it will change the capacitance value at the touch location, and the touch point is located by the change in capacitance value.

[0003] However, a common drawback of capacitive touchscreens is that when a water droplet falls on the screen, it changes the capacitance value, triggering the touch function and causing inconvenience to the user. Summary of the Invention

[0004] This application is made in order to solve at least one of the above problems.

[0005] This application provides a capacitive touch screen, including a touchpad, an LCD panel, a backlight panel, and a circuit board;

[0006] The touchpad also includes an upper electrode layer, an insulating layer, a lower electrode layer, and a controller;

[0007] The upper electrode layer comprises several transverse rhomboid electrode sheets;

[0008] The lower electrode layer comprises several longitudinal rhomboid electrode sheets;

[0009] The upper electrode layer and the lower electrode layer are arranged vertically, and the transverse rhomboid electrode sheets and the longitudinal rhomboid electrode sheets are arranged alternately.

[0010] The insulating layer is disposed between the upper electrode layer and the lower electrode layer;

[0011] The controller is connected to the upper electrode layer and the lower electrode layer and is used to cyclically read the capacitance value of each electrode sheet;

[0012] It also includes at least one temperature sensor, which is mounted on the insulating layer and used to sense the temperature of each of the upper electrode layers;

[0013] The controller connects to all the temperature sensors and determines the touch location when the temperature at the location where the capacitance value changes exceeds a specified threshold.

[0014] The LCD panel is attached to the back of the touchpad and is used to display patterns;

[0015] The backlight panel is attached to the back side of the liquid crystal panel and is used to provide light;

[0016] The circuit board is located on the back side of the backlight panel and is connected to the controller, the LCD panel and the backlight panel, and is used for data command processing.

[0017] In one embodiment, at least one of the temperature sensors is mounted in the gap between the two transverse rhomboid electrode plates.

[0018] In one embodiment, the interval between two adjacent temperature sensors is at least greater than the total length of the two rhomboid electrode sheets.

[0019] In one embodiment, the horizontal dimension of the temperature sensor is 0.75~1.2mm.

[0020] In one embodiment, the controller is mounted at the edge of the insulating layer and located between the insulating layer and the liquid crystal panel.

[0021] In one embodiment, the surface of the controller is covered with a rubber layer;

[0022] The rubber layer is bonded to the liquid crystal panel by adhesive.

[0023] In one embodiment, the liquid crystal panel includes a first polarizing plate, a second polarizing plate, a glass substrate, a liquid crystal molecule structure, and an electric field application structure.

[0024] The first polarizing plate and the second polarizing plate are arranged side by side, with a gap between them;

[0025] The glass substrate is in close contact with the first polarizing plate;

[0026] The liquid crystal molecule structure is located between the glass substrate and the first polarizing plate;

[0027] The electric field application structure is installed on both sides of the liquid crystal molecule structure and connected to the circuit board, and is used to apply an electric field to the liquid crystal molecule structure.

[0028] The electric field releasing structure is connected to the circuit board and is used to control the on / off state of the electric field of the electric field releasing structure.

[0029] In one embodiment, the electric field dispensing structure includes a positive terminal, a negative terminal, and a power source;

[0030] The positive and negative ends are located on both sides of the liquid crystal molecule structure;

[0031] The power supply is connected to the circuit board and is used to supply voltage to the positive and negative terminals under the control of the circuit board.

[0032] In one embodiment, the backlight panel includes a reflector, a light guide plate, a prism plate, and a light source;

[0033] The reflector and light guide plate are arranged close together on one side;

[0034] The light source is located on the bottom side of the light guide plate;

[0035] The prism plate is located on the other side of the light guide plate and is in close contact with the liquid crystal panel.

[0036] In one embodiment, the light source is an LED light source.

[0037] The above embodiments have the following beneficial effects: during operation, a certain capacitance value is formed between several horizontal rhomboid electrode sheets of the upper electrode layer and several vertical rhomboid electrode sheets of the lower electrode layer, and at the same time, the temperature sensor also detects the temperature at various positions on the screen.

[0038] When an object touches the touchpad, the controller can sense the change in capacitance between the upper and lower electrode layers and convert it into a voltage signal, which is then sent to the circuit board.

[0039] In addition, the temperature sensor located on the touchpad also detects the temperature of the object and transmits the temperature data to the circuit board. If the object is a hand, the temperature sensor will detect a higher temperature. The circuit board determines the touch position based on the temperature exceeding a specified threshold at the location where the capacitance value changes, and then executes the corresponding function for that touch position. Conversely, if the object is a water droplet, the temperature sensor will detect a lower temperature. In this case, although the circuit board can sense the change in capacitance value, the temperature is low, so the corresponding function for that touch position is not executed.

[0040] Therefore, when a water droplet falls onto the screen, the capacitive touchscreen will not function as a touch point, thus improving the user experience. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a simplified exploded view of the capacitive touchscreen structure according to an embodiment of the present invention;

[0043] Figure 2 A simplified exploded view of the touchpad;

[0044] Figure 3 This is a front view of the touchpad;

[0045] Figure 4 A simplified exploded view of the backlight panel;

[0046] Figure 5 This is a simplified diagram of an LCD panel.

[0047] Reference numerals: 1. Touch panel; 11. Upper electrode layer; 12. Insulating layer; 13. Lower electrode layer; 14. Controller; 15. Glass plate; 2. Liquid crystal panel; 211. First polarizing plate; 212. Second polarizing plate; 213. Glass substrate; 214. Liquid crystal molecule structure; 215. Positive terminal; 216. Negative terminal; 217. Power supply; 3. Backlight panel; 31. Reflector; 32. Light guide plate; 33. Prism plate; 34. Light source; 4. Circuit board; 5. Temperature sensor. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of the present invention, and not all of the embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of the present invention.

[0049] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0050] It should be understood that the invention can be embodied in various forms and should not be construed as being limited to the embodiments set forth herein. Rather, providing these embodiments will make the disclosure thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0051] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. When used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “compose” and / or “comprising,” when used in this specification, confirm the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups. When used herein, the term “and / or” includes any and all combinations of the associated listed items.

[0052] To fully understand this invention, a detailed structure will be presented in the following description to illustrate the technical solution proposed by this invention. Optional embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0053] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0054] like Figures 1 to 3 As shown, this application provides a capacitive touch screen, including a touchpad 1, a liquid crystal panel 2, a backlight panel 3, and a circuit board 4;

[0055] The touchpad 1 also includes an upper electrode layer 11, an insulating layer 12, a lower electrode layer 13, and a controller 14;

[0056] The upper electrode layer 11 includes several transverse rhomboid electrode sheets;

[0057] The lower electrode layer 13 includes several longitudinal rhomboid electrode sheets;

[0058] The upper electrode layer 11 and the lower electrode layer 13 are arranged vertically, and the transverse rhomboid electrode sheets and the longitudinal rhomboid electrode sheets are arranged alternately.

[0059] Insulating layer 12 is disposed between upper electrode layer 11 and lower electrode layer 13;

[0060] The controller 14 is connected to the upper electrode layer 11 and the lower electrode layer 13 and is used to cyclically read the capacitance value of each electrode sheet;

[0061] It also includes at least one temperature sensor 5, which is mounted on the insulating layer 12 and is used to sense the temperature of each upper electrode sheet;

[0062] The controller 14 connects to all temperature sensors 5. When the temperature at the location where the capacitance value changes exceeds a specified threshold, the touch location is determined.

[0063] The LCD panel 2 is attached to the back of the touchpad 1 and is used to display patterns;

[0064] The backlight panel 3 is attached to the back side of the LCD panel to provide light;

[0065] Circuit board 4 is located on the back side of backlight panel 3 and is connected to controller 14, LCD panel 2 and backlight panel 3 for processing data instructions.

[0066] In this embodiment, the capacitive touchscreen, from the outside in, includes a touchpad 1, a liquid crystal panel 2, a backlight panel 3, and a circuit board 4. The touchpad 1, liquid crystal panel 2, and backlight panel 3 can be connected by adhesive, snap-fit, or other methods.

[0067] The touchpad is described in detail below. The touchpad 1 mainly includes an upper electrode layer 11, an insulating layer 12, a lower electrode layer 13, and a controller 14. The upper electrode layer 11, the insulating layer 12, and the lower electrode layer 13 are connected in sequence, preferably by adhesive. A transparent glass plate 15 is additionally mounted on the outside of the upper electrode layer 11, allowing the user to touch the screen through the transparent glass plate 15.

[0068] The upper electrode layer 11 is specifically composed of several transverse rhomboid electrode sheets, and the lower electrode layer 13 is specifically composed of several longitudinal rhomboid electrode sheets, wherein adjacent rhomboid electrode sheets are connected by tiny conductive materials. Each transverse rhomboid electrode sheet and each longitudinal rhomboid electrode sheet are staggered in the transverse direction, and an insulating layer 12 is provided between the transverse and longitudinal rhomboid electrode sheets, so that when energized, the transverse and longitudinal rhomboid electrode sheets form a stable capacitance value.

[0069] Several temperature sensors 5 are provided, specifically distributed on the side of the insulating layer 12. When the transverse rhomboid electrode plates are connected to the insulating layer 12, the temperature sensors 5 are located exactly in the gap formed between the two transverse rhomboid electrode plates, and are used to detect the temperature at various positions of each upper electrode plate.

[0070] The controller 14 is specifically a microprocessor chip connected to the upper electrode layer 11, the lower electrode layer 13, the temperature sensor 5, and the circuit board 4. It is used to cyclically read the capacitance values ​​of the upper electrode layer 11 and the lower electrode layer 13, as well as the temperature data detected by the temperature sensor 5, and transmit the capacitance values ​​and temperature data to the circuit board 4. The circuit board 4 judges the changes in capacitance and temperature and executes the function of the same touch position.

[0071] Both the LCD panel 2 and the backlight panel 3 are connected to the circuit board 4. The LCD panel 2 is used to display patterns, and the backlight panel 3 is used to provide a backlight 34 for the display of the LCD panel 2.

[0072] When an object touches the touchpad 1 during operation, the controller 14 can sense the change in capacitance between the upper electrode layer 11 and the lower electrode layer 13 and convert it into a voltage signal, which is then sent to the circuit board 4.

[0073] In addition, the temperature sensor 5 located on the touchpad 1 will also detect the temperature of the object and transmit the temperature data to the circuit board 4. If the object is a hand, the temperature sensor 5 will detect a higher temperature. The circuit board 4 will determine the touch position based on the temperature at the location where the capacitance value changes exceeding a specified threshold, and then execute the corresponding function of the touch position. Conversely, if the object is a water droplet, the temperature sensor 5 will detect a lower temperature. At this time, although the circuit board 4 can sense the change in capacitance value, the temperature is low, so the corresponding function of the touch position will not be executed.

[0074] Therefore, when a water droplet falls onto the screen, the capacitive touchscreen will not function as a touch point, thus improving the user experience.

[0075] like Figure 3 As shown, in one possible embodiment, the interval between two adjacent temperature sensors 5 is at least greater than the total length of the two rhomboid electrode sheets.

[0076] In this embodiment, the distance between two adjacent temperature sensors 5 is at least greater than the total length of the two transverse rhomboid electrode pieces. This is because when a person touches the screen with their finger, the touch area of ​​the finger is relatively large compared to the area of ​​the rhomboid electrode pieces. Therefore, the temperature sensors 5 do not need to be arranged too densely. The layout of this solution is sufficient to monitor the temperature of the finger at various locations. At the same time, the arrangement of a small number of temperature sensors 5 can also reduce the overall power consumption of the screen.

[0077] In one embodiment, the horizontal dimension of the temperature sensor 5 is 0.75~1.2mm.

[0078] In this embodiment, the 0.75~1.2mm miniature temperature sensor 5 is now widely used and can be completely installed in the gap between adjacent rhomboid electrode sheets, which has a relatively good temperature detection effect.

[0079] In one embodiment, the controller 14 is mounted at the edge of the insulating layer 12 and located between the insulating layer 12 and the liquid crystal panel 2.

[0080] In this embodiment, preferably, the controller 14 is installed in a preset notch at the top of the insulating layer 12, which neither increases the overall area of ​​the insulating plate nor makes it more secure.

[0081] In one possible implementation, the surface of the controller 14 is covered with a rubber layer (not shown in the figure).

[0082] The rubber layer is connected to the LCD panel 2 by adhesive.

[0083] In this embodiment, the rubber layer is provided for two purposes: firstly, to ensure insulation and prevent the controller 14 from being subjected to interference such as electrostatic discharge; and secondly, to facilitate the connection of the liquid crystal panel 2 with adhesive, making the controller 14 more robust.

[0084] like Figure 4 As shown, in one embodiment, the liquid crystal panel 2 includes a first polarizing plate 211, a second polarizing plate 212, a glass substrate 213, a liquid crystal molecule structure 214, and an electric field application structure.

[0085] The first polarizing plate 211 and the second polarizing plate 212 are arranged side by side, with a gap between them;

[0086] The glass substrate 213 is in close contact with the first polarizing plate 211;

[0087] The liquid crystal molecule structure 214 is located between the glass substrate 213 and the first polarizing plate 211;

[0088] An electric field application structure is installed on both sides of the liquid crystal molecule structure 214 and connected to the circuit board 4 for applying an electric field to the liquid crystal molecule structure 214.

[0089] The electric field releasing structure is connected to the circuit board 4 and is used to control the on / off state of the electric field of the electric field releasing structure.

[0090] In this embodiment, as shown in the figure, the electric field applied by the electric field application structure is horizontal. Therefore, the liquid crystal molecules twist parallel to the substrate. Liquid crystal molecules without an applied electric field are aligned parallel to the substrate (HOMOGENEOUS). The upper and lower polarizing plates are arranged at a 90-degree angle, always remaining perpendicular. The polarization axis of the bottom polarizing plate is the same as the alignment of the liquid crystal molecules. Incident light travels in a straight line through the parallel-arranged liquid crystal layer without changing its direction of travel. The emitted light cannot pass through the upper polarizing plate, thus presenting an opaque black state. After applying an electric field, the liquid crystal molecules twist, producing birefringence in the liquid crystal layer. This changes the direction of travel of the incident light, allowing it to pass through the upper polarizing plate and present a transparent state. When the liquid crystal molecules twist parallel to the substrate without an applied electric field, and the arrangement of the liquid crystal molecules is less than the tilt angle, the viewing angle of the black state increases, resulting in a wider viewing angle for the brightness ratio.

[0091] In one embodiment, the electric field dispensing structure includes a positive terminal 215, a negative terminal 216, and a power supply 217;

[0092] The positive electrode 215 and the negative electrode 216 are located on both sides of the liquid crystal molecule structure 214;

[0093] Power supply 217 is connected to circuit board 4 and is used to supply voltage to the positive terminal 215 and the negative terminal 216 under the control of circuit board 4.

[0094] In this embodiment, during use, the circuit board 4 controls the power supply 217 to turn on or off. When the power supply 217 is turned on, an electric field is applied, and when the power supply 217 is turned off, the electric field is stopped.

[0095] like Figure 5 As shown, in one possible embodiment, the backlight panel 3 includes a reflector 31, a light guide plate 32, a prism plate 33, and a light source 34;

[0096] The reflector 31 and the light guide plate 32 are arranged on one side and closely attached to each other;

[0097] The light source 34 is located on the bottom side of the light guide plate 32;

[0098] The prism plate 33 is located on the other side of the light guide plate 32 and is in close contact with the liquid crystal panel 2.

[0099] In this embodiment, the reflector 31, light guide plate 32, and prism plate 33 are assembled together in a stamping form. The light-emitting plate is used to reflect the surrounding light onto the liquid crystal panel 2; the light source 34 is specifically an LED light source 34, used to emit light of a certain intensity, so that the entire light guide plate 32 emits light; the prism plate 33 is used to shield light in non-perpendicular directions, and finally emits light perpendicular to the backlight plate 3 from the prism plate 33.

[0100] The present invention has been described through the above embodiments. However, it should be understood that the above embodiments are for illustrative purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, those skilled in the art will understand that the present invention is not limited to the above embodiments, and many more variations and modifications can be made based on the teachings of the present invention, all of which fall within the scope of protection claimed by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A capacitive touch screen, characterized by The touch panel, the liquid crystal panel, the backlight panel and the circuit board are included. The touch panel further includes an upper electrode layer, an insulation layer, a lower electrode layer and a controller. The upper electrode layer includes a plurality of horizontal rhombic electrode pieces. The lower electrode layer includes a plurality of vertical rhombic electrode pieces. The upper electrode layer and the lower electrode layer are arranged in a staggered manner. The insulation layer is arranged between the upper electrode layer and the lower electrode layer. The controller is connected to the upper electrode layer and the lower electrode layer, and is configured to cyclically read the capacitance values of the electrode pieces. At least one temperature sensor is further included, and the at least one temperature sensor is arranged on the insulation layer and configured to sense the temperature of each of the upper electrode layers. The controller is connected to all the temperature sensors, and is configured to determine the touch position when the temperature at the position where the capacitance value changes exceeds a specified threshold value. The liquid crystal panel is arranged on the back side of the touch panel and configured to display a pattern. The backlight panel is arranged on the back side of the liquid crystal panel and configured to provide light. The circuit board is arranged on the back side of the backlight panel, and is connected to the controller, the liquid crystal panel and the backlight panel, and is configured to process data instructions.

2. The capacitive touch screen of claim 1, wherein, The at least one temperature sensor is arranged in the gap between two horizontal rhombic electrode pieces.

3. The capacitive touch screen of claim 2, wherein, The interval between two adjacent temperature sensors is greater than the total length of the two rhombic electrode pieces.

4. The capacitive touch screen of claim 3, wherein, The horizontal dimension of the temperature sensor is 0.75-1.2 mm.

5. The capacitive touch screen of claim 1, wherein, The controller is arranged at the edge of the insulation layer and between the insulation layer and the liquid crystal panel.

6. The capacitive touch screen of claim 5, wherein, The surface of the controller is covered with a rubber layer. The rubber layer is connected to the liquid crystal panel by glue.

7. The capacitive touch screen of claim 1, wherein, The liquid crystal panel includes a first polarizing plate, a second polarizing plate, a glass substrate, a liquid crystal molecule structure and an electric field application structure. The first polarizing plate and the second polarizing plate are arranged side by side with a gap therebetween. The glass substrate is arranged on the first polarizing plate. The liquid crystal molecule structure is arranged between the glass substrate and the first polarizing plate. The electric field application structure is arranged on both sides of the liquid crystal molecule structure, and is connected to the circuit board and configured to apply an electric field to the liquid crystal molecule structure. The electric field application structure is connected to the circuit board and configured to control the on-off of the electric field of the electric field application structure.

8. The capacitive touch screen of claim 7, wherein, The electric field application structure includes a positive electrode, a negative electrode and a power supply. The positive electrode and the negative electrode are arranged on both sides of the liquid crystal molecule structure. The power supply is connected to the circuit board and configured to supply voltage to the positive electrode and the negative electrode under the control of the circuit board.

9. The capacitive touch screen of claim 1, wherein, The backlight panel includes a reflecting plate, a light guide plate, a prism plate and a light source. The reflecting plate and the light guide plate are arranged side by side and in close contact. The light source is arranged on the bottom side of the light guide plate. The prism plate is arranged on the other side of the light guide plate and in close contact with the liquid crystal panel.

10. The capacitive touch screen of claim 9, wherein, The light source is an LED light source.

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