Knob device applicable to touch panel

A knob device is applicable to a touch panel. The touch panel includes a plurality of panel sensors. The knob device includes a knob cover, a sensing pad, a compensation sensor and a switch. The sensing pad is arranged between the knob cover and the touch panel. The switch is configured to selectively connect the sensing pad to the compensation sensor. When a move event of the knob device occurs, the switch is turned on and the sensing pad is electrically connected to the compensate sensor through the switch, such that a feedback loop is generated by the sensing pad, the compensation sensor and the touch panel to change a quantity of electric charge of at least one of the plurality of panel sensors. When a touch and rotation event of the knob device occurs, a location of the sensing pad controls a rotation sensing signal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a user interface (UI) mechanism design, and more particularly, to a knob device applicable to a touch panel and capable of sensing finger touch of a user wearing gloves on his/her hands.

2. Description of the Prior Art

Knob devices are often used in general electronic apparatus, such as the knob for volume adjustment on an audio player, the knob for frequency adjustment on a radio and the knob for air conditioning/air volume adjustment on a car console, where many of these electronic apparatuses are equipped with a touch panel. Therefore, how to integrate the knob device and the touch panel to assist user in control has become an issue. In some traditional methods, the touch pad is installed in the knob and then directly mounted on the touch panel, and the function of the knob is achieved by touch effect of the touch pad on the touch panel. For example, when a user rotates the knob, a finger and the touch pad form a loop with the touch panel, such that a cell of the touch panel touched by the touch pad sends a touch signal. According to touch signals of different cells of the touch panel, the angle of rotation of the knob can be captured.

However, it is possible that a user may contact the knob when wearing gloves on his/her hands, and the touch panel may fail to sense any touch of the user. Due to such a sensing problem resulting from gloves on user's hands, the angle of rotation of the knob cannot be captured successfully. Therefore, there is a need for a novel method and associated architecture to improve a sensitivity of the touch panel for fingers with gloves for solving the problems without introducing any side effect or in a way that is less likely to introduce a side effect.

SUMMARY OF THE INVENTION

It is an objective of the present invention to provide a knob device applicable to a touch panel and capable of sensing finger touch of a user wearing gloves on his/her hands, in order to solve the above-mentioned problems.

According to one embodiment of the present invention, a knob device is applicable to a touch panel. The touch panel comprises a plurality of panel sensors. The knob device comprises a knob cover, a sensing pad, a compensation sensor and a switch. The sensing pad is arranged between the knob cover and the touch panel. The switch is configured to selectively connect the sensing pad to the compensation sensor. When a move event of the knob device occurs, the switch is turned on and the sensing pad is electrically connected to the compensate sensor through the switch, such that a feedback loop is generated by the sensing pad, the compensation sensor and the touch panel to change a quantity of electric charge of at least one of the plurality of panel sensors. When a touch and rotation event of the knob device occurs, a location of the sensing pad controls a rotation sensing signal of the touch panel.

DETAILED DESCRIPTION

Please refer toFIG. 1andFIG. 2.FIG. 1is a cross-section view illustrating a knob device100touched by a finger of a user without a glove on user's hand.FIG. 2is a schematic illustrating an equivalent circuit of the knob device100operated under a condition shown inFIG. 1. As shown inFIG. 1, the knob device100is arranged on a touch panel300, and comprises a knob cover110and a sensing pad130arranged between the knob cover110and the touch panel300. The touch panel300comprises a panel cover (e.g., cover glass)310, a display panel330and a plurality of panel sensors350. A display panel capacitor Cp is formed between one of the plurality of panel sensors350and a system ground of the touch panel300, and a panel cover capacitor Cpk is formed between the sensing pad130and the panel sensor350(i.e., one of the plurality of panel sensors350that contributes to the panel cover capacitor Cpk). A finger capacitor Cf is formed between the finger of the user and the system ground of the touch panel300. The sensing pad130has an electrical potential Vk, and the panel sensor350has an electrical potential VRX. As shown inFIG. 2, when the user touches the knob cover110, a loop is generated by the finger capacitor Cf, the panel cover capacitor Cpk, the display panel capacitor Cp, the sensing pad130, the panel sensor350and the system ground. A quantity of electric charge Qn of the panel sensor350is changed from Qn1to Qn2after the user's touch occurs, where Qn1=Cp*VRX, and Qn2=[Cp//(Cpk+Cf)] *VRX. It is noticed that the symbol of “//” means that the capacitors are connected in parallel, and the symbol of “+” means that the capacitors are connected in series. An integrated circuit (IC) of the touch panel300is able to generate a touching signal according to the change of Qn (ΔQn=Qn2−Qn1). In general, the finger capacitor Cf is much greater than the panel cover capacitor Cpk and the display panel capacitor Cp, such that ΔQn is approximately equal to Cpk*VRX. The impedance Zkf between the finger and the knob cover110is omitted in the circuit for simplicity. Since the present invention focuses on the sensing problem, further description associated with control of the knob device100is omitted here for simplicity.

However, certain sensing problems may occur. For example, when the user wears gloves on his/her hands, the touch panel may not sense touch of the user. Please refer toFIG. 3andFIG. 4.FIG. 3is a cross-section view illustrating the knob device100touched by the finger of the user with a glove150on user's hand.FIG. 4is a schematic illustrating an equivalent circuit of the knob device100operated under a condition shown inFIG. 3. As shown inFIG. 3, when a finger of a user with a glove150touches the knob cover110, a glove capacitor Ckf is formed between the finger of the user and the knob cover110. As shown inFIG. 4, the quantity of electric charge Qn of the panel sensor350is changed from Qn1to Qn3after the touch of the user with the glove150occurs, where Qn3=[Cp//(Cpk+Cf+Ckf)] *VRX, and Ckf<<Cpk, such that the glove capacitor Ckf dominates the total capacitance value. The change of Qn (ΔQn=Qn3−Qn1) is approximately equal to Ckf*VRX. Since the glove capacitor Ckf is relatively small, the IC of the touch panel may not be able to detect the change of Qn, which may lead to insensitivity of touch of the user with the glove150. To address above issues, the present invention proposes providing a knob device with a compensation mechanism. Further details of the compensation mechanism are described as below.

Please refer toFIG. 5.FIG. 5is a cross-section view illustrating a knob device200touched by a finger of a user with a glove150on user's hand according to a first embodiment of the present invention. As shown inFIG. 5, the knob device200of the present invention is arranged on a touch panel300, and comprises a knob cover210, a switch220, a compensation sensor250and a sensing pad230, where the sensing pad230is arranged between the knob cover210and the touch panel300. The sensing pad230may move from one position to another position when the knob cover210is rotated by the user. The touch panel300comprises a panel cover (e.g., cover glass)310, a display panel330and a plurality of panel sensors350. In the present embodiment, the plurality of panel sensors350may comprise a first panel sensor351and a second panel sensor352. A first display panel capacitor Cp1is formed between the first panel sensor351and a system ground of the touch panel300, and a first panel cover capacitor Cpk is formed between the sensing pad230and the first panel sensor351. A second display panel capacitor Cp2is formed between the second panel sensor352and a system ground of the touch panel300, and a second panel cover capacitor Cpc is formed between the compensation sensor250and the second panel sensor352. A finger capacitor Cf is formed between the finger of the user and the system ground of the touch panel300. When a finger of a user with the glove150touches the knob cover210, a glove capacitor Ckf is formed between the finger and the knob cover210. The sensing pad230has an electrical potential Vk, and the compensation sensor250has an electrical potential Vc. The first panel sensor351has an electrical potential VRX1, and the second panel sensor352has an electrical potential VRX2. When the finger with the glove150touches the knob cover210, a loop601is generated by the glove capacitor Ckf, the finger capacitor Cf, the sensing pad230, the first panel cover capacitor Cpk, the first panel sensors351and the first display panel capacitor Cp1.

The switch220is arranged in the knob cover210. In the present embodiment, the switch220is a push/pull switch. When the knob cover210is slightly pressed, the switch220is turned on for electrically connecting the sensing pad230to the compensate sensor250. In addition, the switch220has a mechanism (e.g., a spring) that allows the knob cover110to be rebound up when not being pressed, such that the switch is turned off, but the present invention is not limited thereto. This mechanism can be implemented by any elastic component known to those skilled in the art, so the mechanism is not shown in figures, and further description is omitted here for simplicity. Furthermore, when a user touches and slightly presses the knob cover210, the switch220is turned on and the sensing pad230is electrically connected to the compensate sensor250through the switch220, such that a feedback loop (compensation loop)602is generated by the sensing pad230, the compensation sensor250, the first panel cover capacitor Cpk, the first panel sensors351, the first display panel capacitor Cp1, the second panel cover capacitor Cpc, second panel sensor352and the second display panel capacitor Cp2, in order to change a quantity of electric charge of the first panel sensor351. In addition, impedance Zkf between the finger and the knob cover210is omitted in the circuit for simplicity. In the present embodiment, the switch220is turned on by a slightly pressing on the knob cover210, but the present invention is not limited thereto. In some embodiment, the switch can be turned on by slightly moving the knob cover laterally.

Please refer toFIG. 6.FIG. 6is a schematic illustrating an equivalent circuit of the knob device200operated under a condition shown inFIG. 5. As shown inFIG. 6, when the finger of the user with the glove150touches the knob cover210, the loop601is generated. The loop601is similar to the equivalent circuit inFIG. 4, so that the change of a quantity of electric charge Qn of the first panel sensor351in the loop601is small due to the fact that the glove capacitor Ckf is relatively small. When the finger of the user with the glove150touches and slightly presses the knob cover210, the loop601and the feedback loop602are both generated. The quantity of electric charge Qn of the first panel sensor351is changed from Qn1to Qn2after the user's touching and pressing, where Qn1=Cp1*VRX1; Qn2=[Cp1//(Cpk+{(Cf+Ckf)//(Cpc+Cp2)}] *VRX. It is noticed that the symbol of “//” means that the capacitors are connected in parallel, and the symbol of “+” means that the capacitors are connected in series. An integrated circuit (IC) of the touch panel300is able to generate a touching signal according to the change of Qn (ΔQn=Qn2−Qn1), and a rotation sensing signal is further generated according to the touching signal. In other words, when the user touches and rotates the knob device200, the panel sensor under the sensing pad230(e.g., the first panel sensor351) obtains a change of the quantity of electric charge, such that a location of the sensing pad230controls a rotation sensing signal of the touch panel300. It is noticed that the feedback loop602changes the Qn2from [Cp1//(Cpk+Cf+Ckf)] *VRX to [Cp1//(Cpk+{(Cf+Ckf)//(Cpc+Cp2)}] *VRX, such that the small glove capacitor Ckf only dominates the series capacitors (Cpk+{(Cf+Ckf). The change of Qn (ΔQn) can be increased by connecting the series capacitors (Cpc+Cp2) in parallel.

In some embodiments, the knob cover210may be made of metal with excellent conductivity, such that the capacitance value of the glove capacitor Ckf can be increased by enhancing the coupling capability of the knob cover210. However, this is for illustrative purposes only, and is not meant to be a limitation of the present invention.

According to the above arrangements, when the finger of the user with a glove is not able to create enough change of the quantity of electric charge, the feedback loop enabled by the turned-on switch creates the connection of series capacitors (Cpc+Cp2) in parallel, in order to create greater difference of the quantity of electric charge. In addition, the greater capacitance values the second panel cover capacitor Cpc and the second display panel capacitor Cp2have, the greater difference of the quantity of electric charge can be made, such that the knob device200has a better Signal-to-noise ratio (SNR) to the panel sensor300, and the finger of the user with a glove can be more recognizable by the knob device200.

In some embodiments, the second panel sensor352can be controlled by an integrated circuit (IC) channel of the touch panel300to provide a different electrical potential level from other panel sensors350, in order to increase the capacitance values of the second panel cover capacitor Cpc and the second display panel capacitor Cp2. However, this is for illustrative purposes only, and is not meant to be a limitation of the present invention.

Please refer toFIG. 7.FIG. 7is a cross-section view illustrating a knob device202touched by the finger of the user with a glove150on user's hand according to a second embodiment of the present invention. As shown inFIG. 7, the difference between the second embodiment and the first embodiment is that a through hole320is formed in the touch panel300, and the compensation sensor250is arranged in the through hole320and electrically connected to a system ground of the touch panel300. When the finger of the user with the glove150touches and slightly presses the knob device202, the switch220is turned on and a feedback loop603is generated by the sensing pad230, the compensation sensor250, the first panel sensor351, the first panel cover capacitor Cpk, the first display panel capacitor Cp1and the system ground. In the present embodiment, the compensation sensor250has one end directly connected to the system ground, so that the electrical potential Vc of the compensation sensor250is approximately zero, which is equivalent to assigning infinite capacitance values to the second panel cover capacitor Cpc and the second display panel capacitor Cp2inFIG. 6. Hence, compared to the first embodiment, the second embodiment can increase the change of the quantity of electric charge Qn of the first panel sensor351(ΔQn), and can make the first panel sensor351of the knob device202have a better SNR. In the present embodiment, the switch220is turned on by a slightly pressing on the knob cover210, but the present invention is not limited thereto. In some embodiment, the switch can be turned on by slightly moving the knob cover laterally.

Please refer toFIG. 8.FIG. 8is a cross-section view illustrating a knob device204touched by the finger of the user with a glove150on user's hand according to a third embodiment of the present invention. As shown inFIG. 8, the difference between the third embodiment and the first embodiment is that a blind hole340is formed in the panel cover310. The compensation sensor250is arranged in the blind hole340and electrically connected to the second panel sensor352. When the finger of the user with the glove150touches and slightly presses the knob device204, the switch220is turned on and the feedback loop604is generated by the sensing pad230, the compensation sensor250, the first panel sensor351, the second panel sensor352, the first panel cover capacitor Cpk, the first display panel capacitor Cp1, the second display panel capacitor Cp2and the system ground. In the present embodiment, the compensation sensor250has one end directly connected to the second panel sensor352. The second panel sensor352can be controlled by the IC channel of the touch panel300to provide a different electrical potential level from other panel sensors350, in order to increase the capacitance values of the second panel cover capacitor Cpc and the second display panel capacitor Cp2. For example, the second panel sensor352is driven to be a ground (0V) by a drive signal, so that the electrical potential Vc of the compensation sensor250is zero, which is equivalent to assigning an infinite capacitance value to the second panel cover capacitor Cpc inFIG. 6. In other words, through the connection of the compensation sensor250and the second panel sensor352, the electrical potential level of the second panel sensor352is able to be changed by the IC channel of the touch panel300to increase the change of the quantity of electric charge Qn of the first panel sensor351(ΔQn). In the present embodiment, the switch220is turned on by a slightly pressing on the knob cover210, but the present invention is not limited thereto. In some embodiment, the switch can be turned on by slightly moving the knob cover laterally.

Please refer toFIG. 9.FIG. 9is a cross-section view illustrating a knob device206with a protecting layer260according to a fourth embodiment of the present invention. As shown inFIG. 9, the difference between the fourth embodiment and the third embodiment is that a protecting layer260is arranged between the compensation sensor250and the second panel sensor352, such that the compensation sensor250is not directly connected to the second panel sensor352, that is, the compensation sensor250is coupled to the second panel sensor352via the protecting layer260. A protecting layer capacitor (not shown inFIG. 9) is formed between the compensation sensor250and the second panel sensor352. When the finger of the user with the glove150touches and slightly presses the knob device206, the switch220is turned on and the feedback loop606is generated by the sensing pad230, the compensation sensor250, the first panel sensor351, the second panel sensor352, the first panel cover capacitor Cpk, the first display panel capacitor Cp1, the second display panel capacitor Cp2, the protecting layer capacitor and the system ground. Since the protecting layer is thinner than the panel cover310, the protecting layer capacitor is similar to the second panel cover capacitor Cpc inFIG. 6, but has a greater capacitance value. Therefore, the protecting layer capacitor is able to create greater difference of the quantity of electric charge than the second panel cover capacitor Cpc. In the present embodiment, the switch220is turned on by a slightly pressing on the knob cover210, but the present invention is not limited thereto. In some embodiment, the switch can be turned on by slightly moving the knob cover laterally. In addition, the second panel sensor352can also be controlled by the IC channel of the touch panel300to provide a different electrical potential level from other panel sensors350, in order to increase the capacitance values of the protecting layer capacitor and the second display panel capacitor Cp2, to further improve the SNR of the knob device to the touch panel.