TWI734136B - Lighting touchpad - Google Patents

Abstract

A lighting touchpad includes a circuit board and a light-emitting element. The circuit board has an active area. Many first sensor cells and at least one second sensor cell are formed in the active area. Each the first sensors has the same first area and the second sensor cell has a second area which is smaller than the first area. The light-emitting element is set on the active area and near to at least one second sensor cell. The configuration of the present invention is helpful to reduce the touch dead zone (inactive area) of the lighting touchpad.

Description

Illuminated touchpad

The present invention relates to a touch panel, in particular to a light-emitting touch panel.

Capacitive touch panels are widely used in notebook computers or external input devices. Users can perform input functions through operations on the touch panel, such as clicking or moving. If the touchpad has a light-emitting function, it will be able to produce more applications.

One of the objectives of the present invention is to provide a light-emitting touch panel.

One of the objectives of the present invention is to provide a light-emitting touch panel with light-emitting elements arranged in the touch sensing area.

According to the present invention, a light-emitting touch panel includes a circuit board and at least one light-emitting element. The circuit board has a touch sensing area composed of a plurality of sensing units, and the light-emitting element is disposed in the touch sensing area. The touch dead zone of the light-emitting touch panel can be eliminated.

FIG. 1 shows a cross-sectional view of a light-emitting touch panel 10 used in a notebook computer, FIG. 2 shows a top view of the light-emitting touch panel 10, and FIG. 3 shows a top view of a circuit board 12 of the light-emitting touch panel 10. In FIG. 1, the light-emitting touch panel 10 is placed on the holder 24 of the notebook computer and is surrounded by the upper cover 26 of the computer C part. The light-emitting touch panel 10 includes a circuit board 12, a light-emitting element 14, a light guide plate 16, and a cover plate 18. And shading element 20. As shown in FIG. 3, the light-emitting touch panel 10 is a capacitive touch panel. A plurality of sensor cells 28 are provided on the circuit board 12 to form an active area 30. 30 is used to sense the touch of a finger or an object. According to the sensing amount of each sensing unit 28, it can be determined whether the light-emitting touch panel 10 is touched by a finger or an object. The light emitting element 14 is disposed on the circuit board 12 and outside the touch sensing area 30, and the light emitting element 14 may be an LED. The light guide plate 16 is placed above the circuit board 12 and on the side of the light emitting element 14 to guide the light emitted by the light element 14. The cover plate 18 is above the light guide plate 16 and covers the light-emitting elements 14 and the light guide plate 16. The user can use a finger or an object (such as a stylus) to click or move on the cover plate 18 to input commands or perform functions. The cover plate 18 can It is glass or mylar. The light-shielding element 20 surrounds the light guide plate 16 and the light-emitting element 14 on the circuit board 12 to prevent the light emitted by the light-emitting element 14 from passing through the side of the light-emitting touch panel 10. The bottom surface of the light guide plate 16 has a micro structure for reflecting light. The light guide plate 16 has a light incident surface 162 and a light exit surface 164. The light emitted by the light emitting element 14 enters the light guide plate from the light incident surface 162 and is reflected by the microstructure on the bottom surface of the light guide plate 16. The reflected light generated by the microstructure leaves the light guide plate from the light exit surface 164. When the light-emitting element 14 is turned off, no pattern will be displayed on the light-emitting touch panel 10. When the light-emitting element 14 is lit, the light of the light-emitting element 14 enters the light guide plate 16 and is reflected by the microstructure, so that the user can see the digital keyboard pattern shown in FIG. 2 from above the light-emitting touch panel 10. In an embodiment, the microstructures provided on the bottom surface of the light guide plate 16 are arranged in the numeric keyboard pattern shown in FIG. 2, and the cover plate 18 forms a light-transmitting area corresponding to the numeric keyboard pattern. When the light-emitting element 14 is lit, the reflected light generated by the microstructure makes the user see the digital keyboard pattern. In another embodiment, the bottom or surface of the cover plate 18 forms the numeric keyboard pattern, and the area of the numeric keyboard pattern can transmit light, and the bottom surface of the light guide plate 16 is provided with a microstructure on the area corresponding to the numeric keyboard pattern. When the light-emitting element 14 is lit, the microstructure generates reflected light, so that the user can see the digital keyboard pattern on the cover.

In the light-emitting touch panel 10, since the area 22 where the light-emitting element 14 is provided does not have the sensing unit 28, the area 22 cannot be touched and is called a dead zone. In an ideal situation, any area of the light-emitting touch panel 10 should be able to perform touch operations. Therefore, the area 22 cannot perform touch operations, which is quite inconvenient for the user.

FIG. 4 shows an embodiment of the light-emitting touch panel 40 of the present invention, which includes a circuit board 42 and at least one light-emitting element 44. In other embodiments, the light-emitting touch panel 40 further includes a light guide plate 16 and a cover plate 18 as shown in FIG. Its description will not be repeated here.

The circuit board 42 has a touch sensing area 46. A plurality of first sensing units 48 and second sensing units 50, 52 are formed in the touch sensing area 46. In this embodiment, the light-emitting touch panel 40 is one In the capacitive touch panel, a controller 56 is coupled to the sensing units 48, 50, and 52. In an embodiment, the controller 56 can also be installed on the lower surface of the circuit board 42. The controller 56 measures the sensing amount of each sensing unit 48, 50, 52 to determine whether the light-emitting touch panel 40 is touched by a finger or an object and to determine the touched position. The light emitting element 44 is disposed in the touch sensing area 46 and is located between two adjacent second sensing units 50 and 52, and each first sensing unit 48 has the same area A1. The area of each second sensing unit 50, 52 is smaller than the area A1. For example, the area of the second sensing unit 50 is A2, the area of the second sensing unit 52 is A3, and both A2 and A3 are smaller than A1. The areas A2 and A3 can be the same or different. In one embodiment, the areas A2 and A3 are greater than or equal to 50% of the area A1. The above-mentioned area A1 represents the area occupied by each first sensing unit 48 in the touch sensing area 46, and the areas A2 and A3 represent the area occupied by the second sensing units 50 and 52 in the touch sensing area 46, respectively.

Compared with the first sensing unit 48, the second sensing unit 50 has an area A4 less, and the second sensing unit 52 has an area A5 less. The light emitting element 44 is disposed in the area formed by the areas A4 and A5, and is adjacent to the second sensing units 50 and 52. It can be seen from FIG. 4 that the arrangement of the first sensing unit 48 and the second sensing units 50 and 52 makes the touch sensing area 46 have a gap without a sensing unit, that is, areas A4 and A5. The light emitting element 44 is set at the position of this gap.

Compared with FIG. 3, the light-emitting element 44 is arranged in the touch sensing area 46, so the circuit board 42 does not have the area 22, which significantly reduces the area (dead zone) where touch input cannot be performed. On the other hand, because the circuit board 42 does not have the area 22, the area of the touch sensing area 46 can be larger than the area 30 of FIG. 3, which can provide the user with a larger touch sensing area for touch input. Since the light-emitting element 44 is adjacent to the second sensing units 50 and 52, and the size of the finger is generally larger than the area A1, even if the finger is operated at the position of the light-emitting element 44, it will cause the second sensing unit 50 and/or 52 to fail. The capacitance changes so that finger operations can still be recognized.

In other embodiments, the light-emitting element 44 may also be adjacent to only one second sensing unit. As shown in FIG. 5, the light emitting element 44 is adjacent to the second sensing unit 54. The area A6 of the second sensing unit 54 is smaller than the area A1, and the area A6 may be greater than or equal to 50% of the area A1. It can be seen from FIG. 5 that the area occupied by the light-emitting element 44 and the sensing unit 54 is equivalent to the area A1.

The circuit board 42 is formed with a plurality of electrodes X and Y coupled to a controller 56, and the direction of the electrode X and the electrode Y is perpendicular. The plurality of electrodes X and Y are formed in all the sensing units in the touch sensing area 46. To facilitate the description of the first sensing unit 48 and the second sensing units 50 and 52, FIG. 6 only shows the electrodes X1 to X3 and the electrodes Y1 to Y2. The electrodes Y1 and Y2 in FIG. 6 are a continuous and curved conductor trace. Each electrode X1~X3 includes a plurality of trace patterns. Each trace pattern of the same electrode X passes through the wires inside the circuit board 42 (for example, the second Layer or third layer wire) and electrically connected. Each of the first sensing unit 48 or the second sensing unit 50 and 52 is composed of at least one trace pattern of an electrode X and a part of the trace of an electrode Y intersecting. For example, the first sensing unit 48 is composed of trace patterns X1a and X1b of the electrode X1 and part of the traces of the electrode Y1. In an embodiment, the controller 56 drives the electrode Y1, and the electrode X1 receives the sensing signal of the sensing unit 48, and the controller 56 calculates the sensing amount dV of the sensing unit 48 according to the sensing signal.

The area of the second sensing unit 50 or 52 is different from the area of the first sensing unit 48. The layout of the sensing traces in the second sensing units 50 and 52 is also different from that of the first sensing unit 48. FIG. 6 shows an embodiment of the sensing units 48, 50, 52 in FIG. 4. As shown in FIG. 6, compared with the first sensing unit 48, the lengths of the trace segments 504 and 524 of the second sensing units 50 and 52 are reduced to reserve an area for mounting the light-emitting element 44. FIG. 7 shows a schematic diagram of the light-emitting element 44 disposed in the second sensing units 50 and 52 in FIG. 6. The light-emitting element 44 is disposed in a reserved area and does not overlap the traces of the second sensing units 50 and 52. 6 to 7 are only for convenience of description. In other embodiments, the trace layout of the first sensing unit 48 and the second sensing unit 50 and 52 may have other changes. It can be seen from FIG. 6 that the sum of the trace areas (sensing area) of each first sensing unit 48 is approximately the same, while the sum of the trace areas (sensing area) in the second sensing units 50 and 52 is less than The sum of the trace area of the first sensing unit 48.

The sensing area of the second sensing unit 50 and 52 is smaller than that of the first sensing unit 48. Therefore, under the same conditions, the sensing amount dV generated by the second sensing unit 50 and 52 may be smaller than that of the first sensing unit 48. The induced amount dV. In order to make the first sensing unit 48 and the second sensing units 50 and 52 have substantially the same sensing amount dV under the same contact condition, the sensing amount of the second sensing unit 50 and 52 of the controller 56 receiving the sensing amount is approximately the same. dV is compensated separately. The controller 56 stores the compensation coefficients of the second sensing units 50 and 52. After the controller 56 receives the sensing quantity dV of the second sensing unit 50, the sensing quantity is multiplied by the compensation coefficient to obtain the compensated sensing quantity dV'. The controller 56 performs a touch judgment or a touch position calculation based on the compensated sensing amount dV'. The determination of the compensation coefficient can be carried out through experiments. For example, when a conductor with a fixed area (such as a weight) touches the first sensing unit 48, the inductance dV output by the first sensing unit 48 is 100, and the conductor touches the second sensing unit 50 When the sensing amount dV output by the sensing unit 50 is 80, the compensation coefficient of the second sensing unit 50 can be set as 100/80=1.25. By the compensation of the compensation coefficient of 1.25, the inductance dV' after compensation of the second sensing unit 50 is 80×1.25=100, which is the same as the inductance dV of the first sensing unit 48. In another embodiment, the controller 56 stores the compensation coefficients of the respective first sensing units 48, the second sensing units 50 and 52, wherein the compensation coefficients corresponding to the second sensing units 50 and 52 are larger than the respective first sensing units 50 and 52. The compensation coefficient of the sensing unit 48. By the compensation of the compensation coefficient, the compensated inductance dV' generated by each of the first sensing unit 48 and the second sensing unit 50 and 58 under the same conditions is substantially the same. The controller 56 obtains the sensing quantity dV of each first sensing unit 48 and the sensing quantity dV of the second sensing units 50 and 52, and respectively multiplies the corresponding compensation coefficients to obtain a plurality of compensated sensing quantities dV' . The controller 56 uses the plurality of compensated sensing quantities dV' to determine the touch or calculate the touch position. In an embodiment, the aforementioned compensation coefficients are all greater than or equal to 1. There are many methods for compensating the inductance dV of the second sensing units 50 and 52, and there are also many methods for determining the compensation coefficient. The present invention only lists an easy-to-understand embodiment, and does not limit the present invention.

The above description of the preferred embodiments of the present invention is for the purpose of clarification, and is not intended to limit the present invention to the disclosed form accurately. Modifications or changes are possible based on the above teachings or learning from the embodiments of the present invention Yes, the embodiments are selected and described in order to explain the principles of the present invention and allow those familiar with the technology to use the present invention in various embodiments in practical applications. The technical ideas of the present invention are intended to be derived from the scope of subsequent patent applications and their equality. Decide.

10: Illuminated touchpad 12: Circuit board 14: Light-emitting element 16: light guide plate 162: Glossy Surface 164: Glossy Surface 18: cover 20: Shading element 22: area 24: bracket 26: Computer C part upper cover 28: Sensing unit 30: Touch sensing area 40: Illuminated touchpad 42: circuit board 44: Light-emitting element 46: Touch sensing area 48: The first sensing unit 50: second sensing unit 504: Trace segment 52: second sensing unit 524: Trace segment 54: second sensing unit 56: Controller

Figure 1 shows a cross-sectional view of a light-emitting touchpad used in a notebook computer. Figure 2 shows a top view of a light-emitting touch panel. Figure 3 shows a top view of a circuit board in a light-emitting touch panel. Figure 4 shows an embodiment of the light-emitting touch panel of the present invention. Fig. 5 shows another arrangement of the light-emitting element in Fig. 4. FIG. 6 shows an embodiment of the trace layout of the sensing unit in FIG. 4. FIG. 7 shows a schematic diagram of the light-emitting element arranged in the sensing unit in FIG. 6.

40: Illuminated touchpad

42: circuit board

44: Light-emitting element

46: Touch sensing area

48: The first sensing unit

50: second sensing unit

52: second sensing unit

56: Controller

Claims (6)

A light-emitting touch panel includes: a circuit board with a touch sensing area; a plurality of first sensing units and one or more second sensing units are formed in the touch sensing area, the plurality of The first sensing unit has the same first area, and the second sensing unit has a second area smaller than the first area; a light-emitting element is disposed in the touch sensing area and is adjacent to at least one of the second A sensing unit; a light guide plate arranged on the circuit board to guide the light emitted by the light-emitting element; and a cover plate arranged on the light guide plate; wherein, the plurality of first sensing units The one or more second sensing units are used to detect the touch of a finger or an object. Such as the light-emitting touch panel of claim 1, wherein the second area is greater than or equal to 50% of the first area. Such as the light-emitting touch panel of claim 1, wherein the light-emitting element is located between two adjacent second sensing units. For example, the light-emitting touch panel of claim 2, which further includes a controller for measuring the sensing amount of each of the first sensing unit and the second sensing unit, and the control unit compensates the second sensing unit by a compensation coefficient The sensing amount of the sensing unit. For example, the light-emitting touch panel of claim 1, wherein the cover includes a numeric keyboard pattern, and the area of the numeric keyboard pattern can transmit light. The light-emitting touch panel of claim 1, wherein the circuit board includes a plurality of first electrodes and a plurality of second electrodes, the plurality of first electrodes are perpendicular to the plurality of second electrodes, and the plurality of The first sensing unit and the one or more second sensing units,

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