Input state detection device
First Claim
1. An input state detection device for detecting contact or pressing of an electrically conductive object, comprising:
- an electrostatic capacitive sensor having a first electrode attached to a substrate, a second electrode located on a side of the electrically conductive object to be contacted, and a dielectric layer placed between the first electrode and the second electrode and to be compressed by pressing force applied on the second electrode by the electrically conductive object;
a constant-voltage power supply device having a voltage application terminal connected to a side of the electrostatic capacitive sensor and applying a predetermined voltage to the electrostatic capacitive sensor;
a detector connected in series with the electrostatic capacitive sensor, having a detection terminal connected to the side of the electrostatic capacitive sensor, and detecting an electric current flowing from the detection terminal that changes with electrostatic capacitance of the electrostatic capacitive sensor and electrostatic capacitance of the electrically conductive object;
a state switching switch that changes a configuration of the input state detection device between a first configuration and a second configuration,wherein in the first configuration, the input state detection device is configured such that the voltage application terminal of the constant-voltage power supply device is connected to a side of the first electrode and the detection terminal of the detector is connected to a side of the second electrode, andwherein in the second configuration, the input state detection device is configured such that the voltage application terminal of the constant-voltage power supply device is connected to the side of the second electrode and the detection terminal of the detector is connected to the side of the first electrode;
an input detector for detecting (i) whether the electrically conductive object is in a non-contact state, or in a contact but not pressing state, with respect to a surface of the electrostatic capacitive sensor on the side of the second electrode, based on a value detected by the detector with the state switching switch set to the first configuration of the input state detection device, and (ii) whether the electrically conductive object is in the contact but not pressing state, or in a pressing state, with respect to the second electrode, based on a value detected by the detector with the state switching switch set to the second configuration of the input state detection device,wherein the predetermined voltage applied by the constant-voltage power supply device is a cyclic voltage, andwherein the input detector is an ammeter for detecting the electric current flowing from the detection terminal, and (i) when the input state detection device is in the first configuration, the input detector detects the electric currently flowing from the side of the second electrode, and (ii) when the input state detection device is in the second configuration, the input detector detects the electric currently flowing from the side of the first electrode.
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Accused Products
Abstract
Provided is an input state detection device capable of reliably detecting contact and pressing of an object. A state switching switch can switch a first state in which a voltage application terminal of a constant-voltage power supply is connected to a side of a first electrode and a detection terminal of a detector is connected to a side of second electrodes, and a second state in which the voltage application terminal of the constant-voltage power supply is connected to the side of the second electrodes and the detection terminal of the detector is connected to the side of the first electrode. An input detector detects whether the object is in a non-contact state or in a contact but not pressing state with respect to a surface on the side of the second electrodes based on a value detected by the detector with the state switching switch in the first state.
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Citations
21 Claims
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1. An input state detection device for detecting contact or pressing of an electrically conductive object, comprising:
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an electrostatic capacitive sensor having a first electrode attached to a substrate, a second electrode located on a side of the electrically conductive object to be contacted, and a dielectric layer placed between the first electrode and the second electrode and to be compressed by pressing force applied on the second electrode by the electrically conductive object; a constant-voltage power supply device having a voltage application terminal connected to a side of the electrostatic capacitive sensor and applying a predetermined voltage to the electrostatic capacitive sensor; a detector connected in series with the electrostatic capacitive sensor, having a detection terminal connected to the side of the electrostatic capacitive sensor, and detecting an electric current flowing from the detection terminal that changes with electrostatic capacitance of the electrostatic capacitive sensor and electrostatic capacitance of the electrically conductive object; a state switching switch that changes a configuration of the input state detection device between a first configuration and a second configuration, wherein in the first configuration, the input state detection device is configured such that the voltage application terminal of the constant-voltage power supply device is connected to a side of the first electrode and the detection terminal of the detector is connected to a side of the second electrode, and wherein in the second configuration, the input state detection device is configured such that the voltage application terminal of the constant-voltage power supply device is connected to the side of the second electrode and the detection terminal of the detector is connected to the side of the first electrode; an input detector for detecting (i) whether the electrically conductive object is in a non-contact state, or in a contact but not pressing state, with respect to a surface of the electrostatic capacitive sensor on the side of the second electrode, based on a value detected by the detector with the state switching switch set to the first configuration of the input state detection device, and (ii) whether the electrically conductive object is in the contact but not pressing state, or in a pressing state, with respect to the second electrode, based on a value detected by the detector with the state switching switch set to the second configuration of the input state detection device, wherein the predetermined voltage applied by the constant-voltage power supply device is a cyclic voltage, and wherein the input detector is an ammeter for detecting the electric current flowing from the detection terminal, and (i) when the input state detection device is in the first configuration, the input detector detects the electric currently flowing from the side of the second electrode, and (ii) when the input state detection device is in the second configuration, the input detector detects the electric currently flowing from the side of the first electrode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. An input state detection device for detecting contact or pressing of an electrically conductive object, comprising:
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an electrostatic capacitive sensor having a first electrode attached to a substrate, a second electrode located on a side of the electrically conductive object to be contacted, and a dielectric layer placed between the first electrode and the second electrode and to be compressed by pressing force applied on the second electrode by the electrically conductive object; a constant-voltage power supply device having a voltage application terminal connected to a side of the electrostatic capacitive sensor and applying a predetermined voltage to the electrostatic capacitive sensor; a detector connected in series with the electrostatic capacitive sensor, having a detection terminal connected to the side of the electrostatic capacitive sensor, and detecting potential of the detection terminal that changes with electrostatic capacitance of the electrostatic capacitive sensor and electrostatic capacitance of the electrically conductive object; a state switching switch that changes a configuration of the input state detection device between a first configuration and a second configuration, wherein in the first configuration, the input state detection device is configured such that the voltage application terminal of the constant-voltage power supply device is connected to a side of the first electrode and the detection terminal of the detector is connected to a side of the second electrode, and wherein in the second configuration, the input state detection device is configured such that the voltage application terminal of the constant-voltage power supply device is connected to the side of the second electrode and the detection terminal of the detector is connected to the side of the first electrode; an input detector for detecting (i) whether the electrically conductive object is in a non-contact state, or in a contact but not pressing state, with respect to a surface of the electrostatic capacitive sensor on the side of the second electrode, based on a value detected by the detector with the state switching switch set to the first configuration of the input stated detection device, and (ii) whether the electrically conductive object is in the contact but not pressing state, or in a pressing state, with respect to the second electrode, based on a value detected by the detector with the state switching switch set to the second configuration of the input stated detection device, wherein the detector includes a bridge capacitor connected between the detection terminal of the detector and ground potential; a charge and discharge switching element connected in parallel to the bridge capacitor and discharging an electric charge of the detection terminal to the ground potential when closed; a charge and discharge control device performing discharging the electric charge of the detection terminal to the ground potential when the constant-voltage power supply device does not apply the predetermined voltage to the electrostatic capacitive sensor, and charging the electrostatic capacitive sensor by opening the charge and discharge switching element and causing the predetermined voltage to be applied by the constant-voltage power supply device after the discharging; and a potential detector for detecting potential of the detection terminal as a value proportional to the electrostatic capacitance of the electrostatic capacitive sensor and the electrostatic capacitance of the electrically conductive object in the charging performed by the charge and discharge control device, wherein in the first configuration of the input state detection device, the potential detector detects potential between the side of the second electrode of the electrostatic capacitive sensor connected to the detection terminal and the bridge capacitor, and in the second configuration of the input state detection device, the potential detector detects potential between the side of the first electrode of the electrostatic capacitive sensor connected to the detection terminal and the bridge capacitor. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification