KR20190065017A - Sensing apparatus for approach of object and Sensor strip for the same - Google Patents

Abstract

The present invention relates to an object proximity sensing apparatus and a sensor strip for the same.
According to an aspect of the present invention, there is provided a plasma display panel comprising at least two electrode strips varying in capacitance value according to an approach of an object and branching from one power application point, wherein the two or more electrode strips extend parallel to each other in the longitudinal direction Wherein the sensor strips are formed such that the lengths of the two or more electrode strips from one point of the sensing section to the power application point are different from each other; A sensing unit sensing a change in capacitance value of the sensor strip unit; And a control unit for determining whether an object is approachable by using an electrical signal corresponding to a change in capacitance value sensed by the sensing unit, wherein a phase difference between each electrode strip at one point of the object sensing period An object proximity sensing device is disclosed that is configured to sense a change in capacitance value in the presence of an object.

Description

[0001] The present invention relates to an object proximity sensor, and more particularly,

More particularly, the present invention relates to an object proximity sensing device and a sensor strip for sensing proximity of an object based on a change in capacitance value, An object proximity sensing device for sensing errors due to a dead point by making a phase difference between two or more electrode strips at one point of the electrode strips and for enabling the sensing distance to be increased by superimposing the electric field of each electrode strip, Sensor strip.

Generally, the sensing device for object approach is divided into contact type and non-contact type. The contact type is a method to judge whether an object is approaching by detecting a change of an electrical load or a change of an air pressure caused by an object such as an obstacle, and a non-contact type is a method of changing a capacitance, a change of a magnetic field or an electric field To determine whether or not the obstacle is approachable.

As shown in the schematic configuration diagram of FIG. 1, the electrostatic capacitance type obstacle sensing apparatus according to a conventional example includes a capacitance sensing module 12 for sensing capacitance, a signal output from the capacitance sensing module 12, And a transmission line 20 for transmitting the output signal of the electrostatic capacity sensing module 12 to the control module 18. The control module 18 determines whether the object is approaching the object.

The electrostatic capacity sensing module 12 may include a sensor strip 14 installed along the periphery of a door or window of the vehicle and a sensor strip 14 coupled to an end of the sensor strip 14 to sense the capacitance of the sensor strip 14. [ And capacitive sensing circuit 16.

The sensor strip 14 is formed by inserting a thin band-shaped conductor (for example, a metal material) into an insulator made of a rubber material having a good flexibility, and the conductor is an electrode of a capacitor, The electrostatic capacity when an object exists is different from the electrostatic capacity when there is no object. The sensor strip 14 may be installed on a variety of objects such as a door or window of a vehicle, or a sliding gate, an elevator door, a bridge between a railway track and a platform screen door. Also, the illustrated sensor strips 14 are shown in a straight line, but they may be bent or installed in a curved shape if necessary.

The control module 18 compares, for example, the output signal of the capacitance sensing circuit 16 with a preset reference value to determine whether or not the output signal exceeds the allowable range. At this time, if it is determined that the allowable range is exceeded, for example, the control signal is transmitted to the opening / closing module 30 that automatically turns on / off the door or window of the vehicle to stop the door or operate the door in the opposite direction.

The capacitive sensing circuit 16 is provided with a RF oscillator connected to the sensor strip 14 and the oscillation frequency of the RF oscillator is determined at the time of circuit manufacture so that the capacitive sensing circuit 16 ) Has a constant frequency.

The capacitance of the sensor strip 14 changes and the oscillation frequency of the RF oscillator connected to the sensor strip 14 changes when the human hand or a part of the body approaches the door or the door. When the output signal of the capacitance sensing circuit 16 is out of the allowable frequency range as the oscillation frequency of the RF oscillator changes, the control module 18 determines that there is an object such as an obstacle.

However, in the conventional object proximity sensing apparatus, when any one of the object and the apparatus moves, the distance for sensing the object in comparison with the moving speed is relatively short. Therefore, when the moving speed of the object or apparatus is fast, There is a problem that it can be done.

In addition, the conventional object proximity sensing apparatus has a problem in that a point (hereinafter, referred to as 'dead point') at which an object can not be detected even when the object approaches it is periodically displayed on the sensor strip.

As an example of the prior art, Korean Patent Registration No. 10-0947559 (Registered Mar. 03, 2010) discloses a technique of oscillating a plurality of frequencies alternately at a predetermined period using at least two RF oscillators, And proposed a configuration for solving the problem of inability to detect due to a dead point by preventing the dead point from overlapping.

However, when two or more RF oscillators are used, there is a problem in that the circuit configuration is complicated and the probability of failure increases, and there is a problem that the effect of increasing the detection distance can not be expected by using only a plurality of oscillators.

Korean Registered Patent No. 10-0627922 (Registered on September 18, 2006) Korean Registered Patent No. 10-0947559 (Registered on March 3, 2010)

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a method and apparatus for sensing an approach of an object based on a change in capacitance value and arranging a plurality of electrode strips in parallel, The object proximity sensing device and the sensor strip are provided with a phase difference between the electrode strips so as to prevent a detection error due to a dead point and allow the electric field of each electrode strip to mutually overlap to increase the sensing distance For that purpose.

According to an aspect of the present invention, there is provided a plasma display panel comprising at least two electrode strips, each of which has a variable capacitance value according to an approach of an object and branches from one power application point, Wherein the sensor strips are formed so that the lengths of the two or more electrode strips from one point of the sensing section to the power application point are different from each other; A sensing unit sensing a change in capacitance value of the sensor strip unit; And a control unit for determining whether an object is approachable by using an electrical signal corresponding to a change in capacitance value sensed by the sensing unit, wherein a phase difference between each electrode strip at one point of the object sensing period An object proximity sensing device is disclosed that is configured to sense a change in capacitance value in the presence of an object.

Preferably, the electrode strips include three or more electrode strips, and each electrode strip is sequentially branched from one power application point, and the lengths from one point of the sensing section to the power application point are different from each other .

Preferably, at least two of the electrode strips are branched, and at least two strips are simultaneously branched from one power supply point, and the length of the electrode strip from the power supply point to the start point of the sensing section Are formed so as to have mutual differences.

Preferably, the length difference between the electrode strips is smaller than the maximum length difference obtained based on the following formula (1).

[Equation 1]

(d _max : Maximum length difference [m], c: Speed of light [m / s], f: Power input frequency applied to sensor strip [Hz]

Preferably, the sensor strip portion includes a first electrode strip formed by disposing the at least two electrode strips, and a second electrode strip disposed to maintain a predetermined longitudinal gap in a state of mutually opposing the first electrode strip, And a second electrode strip provided so as to have an opposite area covering all the strips.

Preferably, the first electrode strip forms a (+) electrode and the second electrode strip forms a ground or (-) electrode.

Preferably, the sensing unit includes: a RF oscillator connected to the sensor strip unit, the oscillation frequency of which varies according to a change in capacitance value of the sensor strip unit; and a control unit connected to the RF oscillator, And a phase locking loop unit for controlling the RF oscillator to maintain a reference oscillation frequency when the oscillation frequency of the RF oscillator changes from a reference oscillation frequency.

Preferably, the detection of change in the capacitance value is performed in a state where electric fields generated by the respective electrode strips overlap each other at one point of the object detection period.

According to another aspect of the present invention, there is provided a plasma display apparatus comprising: at least two electrode strips varying in capacitance value according to an approach of an object and branching from a power application point, wherein the at least two electrode strips are parallel to each other along a longitudinal direction And the two or more electrode strips are formed such that lengths from one point of the sensing section to the power application point are different from each other.

The present invention has the advantage that the sensing area can be widened by arranging a plurality of electrode strips in parallel.

Particularly, the present invention allows a phase difference to be generated between each electrode strip simply without a circuit element for phase control, and it is advantageous to prevent a detection error problem due to a dead point of the electrode strip due to such a phase difference have.

Further, the present invention is advantageous in that the electric field of two or more electrode strips are overlapped with each other, thereby increasing the distance for sensing an object approach.

1 is a schematic block diagram of a conventional object proximity sensing apparatus.
2 is a block diagram of a control circuit of an object proximity sensing apparatus according to an embodiment of the present invention.
3 is a schematic diagram of an electrode strip according to an embodiment of the present invention.
4 is a schematic diagram of a sensor strip according to an embodiment of the present invention.
5 is a schematic diagram for explaining a sensing state of a sensor strip according to an object proximity sensing apparatus according to an embodiment of the present invention.
FIG. 6 is an electric field superposition scheme between electrode strips in an object proximity sensing apparatus according to an embodiment of the present invention. FIG.
7 is a schematic view of an electrode strip according to another embodiment of the present invention.
8 is a perspective view of a sensor strip according to an embodiment of the present invention.

The present invention may be embodied in many other forms without departing from its spirit or essential characteristics. Accordingly, the embodiments of the present invention are to be considered in all respects as merely illustrative and not restrictive.

The terms first, second, etc. are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

When an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may be present in between.

The singular expressions used in the present application include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises ", " comprising "," having ", and the like, are used to denote that there is an element described in the specification or a combination thereof, It is not excluded in advance.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a schematic diagram of an electrode strip according to an embodiment of the present invention, FIG. 4 is a schematic view of a sensor strip according to an embodiment of the present invention, FIG. It is a schematic diagram of wealth.

The object proximity sensing device of the present embodiment has a structure in which a plurality of electrode strips are arranged in parallel to widen the sensing area.

The object proximity sensing apparatus according to an embodiment of the present invention includes two or more electrode strips 110a, 110b, and 110c that are variable in capacitance value in accordance with the approach of the object 500 and branch from one power application point (a) A sensing unit 100 for sensing a change in the capacitance value of the sensor strip unit 110 and a sensor unit 110 for sensing a change in the capacitance value sensed by the sensing unit 100. [ And a control unit 200 for determining whether or not the object 500 is accessed using a signal.

For example, as shown in FIG. 3, the two or more electrode strips 110a, 110b, and 110c in the sensor strip unit 110 include an object sensing section D extending in parallel to each other along the longitudinal direction And the two or more electrode strips 110a, 110b and 110c are formed such that the lengths from one point b of the sensing section D to the power application point a are different from each other.

The object sensing interval D represents an interval during which object sensing can be performed in each of the electrode strips 110a, 110b and 110c and an object sensing interval D of each of the electrode strips 110a, 110b and 110c is It is preferable that they are formed to have the same length.

In the present embodiment, an 'object' may be a person or object that needs to be approached for safety purposes (eg, avoiding collision).

The sensor strip part 110 is formed in a state where the two or more electrode strips 110a, 110b and 110c and the two or more electrode strips 110a, 110b and 110c are maintained in predetermined horizontal intervals d1 and d2, As shown in FIG.

The widths w1, w2, and w3 of the electrode strips 110a, 110b, and 110c are preferably equal to each other so as to have the same impedance.

The electrode strips 110a, 110b and 110c are made of, for example, a strip-shaped conductive material, and a detailed description will be given later.

The predetermined transverse spacings d1 and d2 are distances that allow the electric fields formed by the respective electrode strips 110a, 110b and 110c to overlap with each other. The widths of the electrode strips 110a, 110b and 110c The length from one point (b) to the power application point (a) of the sensing section (D) contributes to mutual differences.

The spacing d1 and d2 may be appropriately adjusted according to the widths w1, w2 and w3 of the electrode strips 110a, 110b and 110c.

For example, the widths w1, w2 and w3 of the respective electrode strips 110a, 110b and 110c are in a flat strip structure of 5 cm, , and d2 are 2 cm and 3 cm, respectively. The arrangement of such electrode strips and the phase difference described below can provide an effect of preventing a detection error due to a dead point compared with the case of constituting one flat strip with a sensing area similar to that of a single flat strip having a width of 20 cm And an effect of providing an increased object approaching distance due to electric field overlap between the respective electrode strips can be obtained.

In the present embodiment, for convenience of description, the distances d1 and d2 between the electrode strips 110a, 110b and 110c have different values. However, the interval between the electrode strips 110a, 110b and 110c (d1, d2) may have the same value.

The body portion 112 is spaced apart from the electrode strips 110a, 110b and 110c by a gap between the electrode strips 110a, 110b and 110c and a conductor (e.g., a conductor strip) And functions as a frame of the sensor strip unit 110. [0035]

The body part 112 may be formed of a synthetic resin material or a synthetic rubber material having a predetermined dielectric property and elasticity.

For example, the sensor strip portion 110 includes first electrode strips 110a, 110b, and 110c formed by disposing the at least two electrode strips 110a, 110b, and 110c, and first and second electrode strips 110a, , A second electrode strip (110 ') disposed to maintain a predetermined longitudinal spacing (c) in a state of being in contact with the first electrode strips (110a, 110b, 110c) It is done.

For example, the first electrode strips 110a, 110b and 110c form a positive electrode and the second electrode strip 110 'is configured to form a ground or negative electrode, An electric field for capacitance sensing is formed based on the electric field formed by the electrode strips 110a, 110b, and 110c and the second electrode strip 110 '.

The first electrode strips 110a, 110b, and 110c and the second electrode strip 110 'may be understood to be formed by processing a conductive material, such as a metal plate or a metal plate, in the form of a plate similar to a strip. The actual implementation of each of the electrode strips 110a, 110b, 110c, 110 'is preferably in the form of a plate, but if it has a configuration, size, and position capable of forming an electric field for capacitive sensing, It is not necessary to be formed into a plate-like shape of the illustrated form.

The object proximity sensing apparatus according to the present embodiment is characterized in that a change in capacitance value in a state having a phase difference between the electrode strips 110a, 110b, and 110c at one point b of the object sensing interval D, .

For example, as shown in FIG. 3, at least three electrode strips 110a, 110b, and 110c are provided, and each of the electrode strips 110a, 110b, Two or more strips are formed at the same time so that the lengths of the electrode strips from the power application point (a) to the start point of the sensing section (D) are different from each other.

For example, the length of the electrode strip 110a from the power applying point (a) to the start point of the sensing section (D) is the shortest distance of a-b1, the distance from the power applying point The length of the electrode strip 110b to the start point of the sensing electrode D is the shortest distance of a-b2 and the length of the electrode strip 110c from the power applying point a to the start point of the sensing period D The length means the shortest distance of a-b3, and each length has a mutual difference.

At a certain point b of the sensing section D, due to the difference in length between the electrode strips 110a, 110b, and 110c, the sensor strip section 110 is separated by the RF oscillator 152, 110b, and 110c with respect to the alternating current power applied to the electrode strips 110a, 110b, and 110c.

Since the electrode strips 110a, 110b and 110c are formed to have the same length in the sensing section D, the electrode strips 110a, 110b and 110c , And a phase difference between the electrode strips 110a, 110b, and 110c is generated in the entire sensing period D, as shown in FIG.

One point (b) or another point (not shown) of the sensing section D indicates the position of sensing the approach of the object in the sensor strip section 110. Each electrode strip 110a, 110b, The object 500 can be sensed at the corresponding position of the object 110c.

That is, one point b of the sensing period D is a point of one of the electrode strips 110a, 110b, and 110c and a point of one of the electrode strips nearest to the one of the electrode strips 110a, May be understood as a point connecting a point of another electrode strip of the electrode strips 110a, 110b, and 110c linearly in the longitudinal direction of each of the electrode strips 110a, 110b, and 110c arranged in the sensing period D. For example, In a direction perpendicular to the X-direction.

For example, the length difference between the electrode strips 110a, 110b, and 110c is smaller than the maximum length difference obtained based on the following equation (1).

[Equation 1]

(d _max : maximum length difference [m], c: speed of light [m / s], f: power supply input frequency [Hz] applied to sensor strip section 110)

The power supply input frequency can be understood as an oscillation frequency of an RF oscillator 152, which will be described later in detail.

For example, when the power supply input frequency applied to the sensor strip unit 110 is 1 GHz, the maximum length difference d _max between the electrode strips 110a, 110b, and 110c is 3 x 10 ⁸ m / s) divided by 2 x 10 < ⁹ > Hz and 0.15 m (15 cm).

When the difference in length between the electrode strips 110a, 110b and 110c is less than 15 cm, the phase difference between the electrode strips 110a, 110b, and 110c is within a wavelength, 110c to have the same phase value after passing through one wavelength can be prevented. In addition, since the length of the electrode strip is prevented from becoming unnecessarily long or complicated, the size (e.g., area) of the sensor strip 110 can be minimized.

When the object 500 approaches the sensor strip portion 110, a change occurs in capacitance values formed by the first electrode strips 110a, 110b, and 110c and the second electrode strip 110 ' The sensing unit 100 senses whether or not the change is detected, and the control unit 200 detects whether the object 500 is present.

For example, the sensing unit 100 may include a RF oscillator, which is connected to the sensor strip unit 110 and whose oscillation frequency varies according to a change in capacitance value of the sensor strip unit 110, And a phase locked loop portion for controlling the RF oscillator to maintain the reference oscillation frequency when the oscillation frequency of the RF oscillator changes from the reference oscillation frequency in accordance with the change of the capacitance value .

The control unit 200 is connected to the phase locked loop unit and uses an electrical signal received from the phase locked loop unit while the phase locked loop unit controls the RF oscillator 152 to maintain the reference oscillation frequency And an MCU 250 (Micro Controller Unit) for determining whether the object 500 is in close proximity.

For example, as shown in FIG. 2, the second electrode strip 110 'may be in a grounded state and the first electrode strips 110 a, 110 b, and 110 c may be connected to the RF oscillator 152.

At this time, due to the difference in length between the electrode strips 110a, 110b and 110c, phase differences are generated between the electrode strips 110a, 110b and 110c, The value is changed.

In this embodiment, when a change occurs in the capacitance of the sensor strip unit 110, a capacitive sensing circuit including a RF oscillator 152 for outputting a corresponding signal and a phase locked loop unit is configured.

The capacitance sensing circuit is electrically connected to the MCU 250 and receives an output signal of the phase locked loop unit to determine whether the object 500 is in proximity to the object.

5 is a schematic diagram for explaining a sensing state of a sensor strip according to an object proximity sensing apparatus according to an embodiment of the present invention. For simplicity, only two electrode strips are illustrated in Fig.

The RF oscillator 152 is connected to the sensor strip unit 110 so that the AC power waveform according to the oscillation frequency can be applied to the sensor strip unit 110.

For example, when the frequency generated by the RF oscillator 152 is 1 GHz, a dead point appears at intervals of about 15 cm in the sensor strip portion 110 formed of a single electrode strip formed within a length of about 2 m.

In this embodiment, the sensor strip portion 110 is formed of two or more electrode strips 110a, 110b, and 110c, and a phase difference is generated according to a length difference between the electrode strips 110a, 110b, and 110c .

For example, FIG. 5A illustrates the position of a dead point of one of the electrode strips, and FIG. 5B illustrates another example where a phase difference is generated according to a difference in length between any one of the electrode strips The position of the dead point of one electrode strip is illustrated.

Since the dead point is formed at different positions for each of the electrode strips 110a, 110b, and 110c due to the phase difference between the electrode strips 110a, 110b, and 110c according to the present embodiment, Since there is always an electrode strip at which a dead point is not formed at any one point b of the sensing section D, it is possible to prevent a dead point from being detected when sensing an object in the sensing section D formed in the sensor strip section 110 An object detection error problem at a specific position will not occur.

For example, the RF oscillator 152 is preferably a VCO (Voltage Controlled Oscillator) capable of adjusting a frequency by a voltage, but the present invention is not limited thereto.

The phase locked loop unit maintains the oscillation frequency of the RF oscillator 152 constant. That is, the phase locked loop unit is a frequency control circuit (control circuit) configured to automatically correct (correct) the difference between the set reference oscillation frequency and the oscillation frequency according to the change of the capacitance value of the sensor strip unit 110 .

That is, when the oscillation frequency of the RF oscillator 152 changes from the reference oscillation frequency according to the change of the capacitance value, the PLL controls the RF oscillator 152 to maintain the set reference oscillation frequency at all times.

The MCU 250 is connected to the phase locked loop unit and determines whether the object 500 is close to the object based on a change in the oscillation frequency value of the RF oscillator 152 according to the change of the capacitance value. The reference oscillation frequency value of the RF oscillator 152 may be preset in the MCU 250.

That is, when the capacitance value changes in the sensor strip portion 110 according to the proximity of the object 500, the oscillation frequency of the RF oscillator 152 changes from the reference oscillation frequency, The voltage applied to the RF oscillator 152 is controlled to cancel the change of the frequency, thereby maintaining the oscillation frequency of the RF oscillator 152 constant. In the description of the present embodiment, a voltage set so that the oscillation frequency of the RF oscillator 152 maintains the reference oscillation frequency can be understood as a 'frequency setting voltage', and the oscillation frequency of the RF oscillator 152 is changed from the reference oscillation frequency The voltage applied to cancel it can be understood as a 'frequency adjustment voltage'.

The frequency adjustment voltage value for controlling the oscillation frequency of the RF oscillator 152 is transmitted to the MCU 250 through an ADC (Analog-to-Digital Converter) 251 in the form of an electrical signal, 250, it is determined that the object 500 is close to the sensor strip unit 110. In this case,

The MCU 250 is connected to an input unit 162 for control setting input and output and a power supply unit 163 for power supply through a transmission line 253 and is connected to the actuator module 170 and the alarm unit 170 via an interface 264. [ (Not shown). For example, the interface 264 includes a known RS232 interface, and various interfaces available to the actuator module 170 and the alarm unit 180 may be applied.

The MCU 250 detects an electrical signal (for example, a voltage value for frequency adjustment) output from the phase locked loop unit to determine whether the object 500 is close to the object 500, and generates an alarm signal indicating object detection.

The power supply unit 163 includes a sensor strip unit 110, an RF oscillator 152, a phase detector 153, and a phase detector 154. The input unit 162 is connected to the MCU 250, A fixed loop unit, and a DC power source of, for example, DC 5V.

The phase locked loop unit of this embodiment will be described in more detail.

The phase locked loop section of this embodiment includes a variable capacitance diode 141 whose one end is connected to the RF oscillator 152, a phase locked loop IC 142, a phase locked loop IC 142 and a variable capacitance diode 141 A frequency adjustment signal line 143 to be connected, and a frequency detection capacitor 144. Reference numeral 147 is an oscillator that provides a reference frequency to the phase locked loop IC 142. In this embodiment, a frequency detection capacitor 144 is used as frequency detection means for continuously sensing the oscillation frequency of the RF oscillator 152. [ If the oscillation frequency of the RF oscillator 152 can be transmitted to the phase locked loop IC 142, it is needless to say that the frequency detecting means may include other known elements in addition to the exemplified frequency detecting capacitor 144.

The variable capacitance diode 141 has a property of varying capacitance according to the applied voltage and has one end connected to the frequency adjusting signal line 143 and the other end grounded.

In a state in which the oscillation frequency of the RF oscillator 152 maintains the reference oscillation frequency without the proximity of the object 500, the frequency setting voltage corresponding to the reference oscillation frequency maintains the set value.

When the oscillation frequency of the RF oscillator 152 tends to deviate from the reference oscillation frequency due to the proximity of the object 500, the voltage for frequency adjustment is applied to the variable capacitance diode 141 or the voltage for frequency adjustment during application is appropriately changed So that the reference oscillation frequency is maintained.

It is understood that applying or changing the voltage for frequency adjustment further applies the voltage for frequency adjustment in addition to the frequency setting voltage originally applied to the variable capacitance diode 141 to oscillate the reference oscillation frequency under the condition of + or - . It may be understood from the viewpoint of applying a frequency adjustment voltage for adaptively maintaining the reference oscillation frequency in place of the frequency setting voltage from another viewpoint.

The RF oscillator 152 and the phase locked loop IC 142 are connected in parallel to the variable capacitance diode 141.

The phase locked loop IC 142 is controlled by the MCU 250 and continuously detects the oscillation frequency of the RF oscillator 152 through a frequency detection capacitor 144, The frequency adjustment voltage is supplied to the variable capacitance diode 141 through the frequency adjustment signal line 143 to control the oscillation frequency of the RF oscillator 152 to maintain the reference oscillation frequency when the frequency is changed from the reference oscillation frequency .

In this control, an electric signal received by the MCU 250 from the phase locked loop unit is used as a frequency adjusting voltage to be supplied from the phase locked loop IC 142 to the variable capacitance diode 141 .

A loop filter 145 may be provided on the frequency adjusting signal line 143 to filter an unnecessary signal from an input voltage to the RF oscillator 152.

With this configuration, for example, the oscillation frequency of the RF oscillator 152 can be kept constant by using the phase locked loop IC 142 in the phase locked loop section in the object detection mode.

That is, since the oscillation frequency of the RF oscillator 152 changes when the object 500 is positioned around the sensor strip 110 and the capacitance of the sensor strip 110 changes, The oscillation frequency is kept constant by appropriately changing the voltage for frequency adjustment to be applied to the variable capacitance diode 141 in FIG.

In this embodiment, the MCU 250 controls the driving of the phase locked loop IC 142 in the phase locked loop section, while the change in the frequency adjusting voltage is controlled via the frequency adjusting signal line 143 connected to the loop filter 145 Detection. Then, the MCU 250 determines whether the object 500 is in close proximity based on the sensed voltage value.

For example, when it is determined by the MCU 250 that the object 500 is close to the sensor strip unit 110, the MCU 250 controls the alarm unit 180 to generate an alarm signal indicating the object detection.

The MCU 250 may control whether an actuator module that automatically opens or closes a window or a door of an automobile according to whether an object is sensed or not.

The MCU 250 may be implemented with a hardware configuration that stores a change in the voltage for frequency adjustment as a reference signal and mounts software for a function such as determining whether the object 500 exists or implements the algorithm. Further, two or more MCUs may execute the distributed processing to share control functions.

The detection of the change of the capacitance value is performed in a state where electric fields generated by the electrode strips 110a, 110b, and 110c are overlapped with each other at one point b of the object sensing period D.

At one point b of the sensing period D, the electric fields generated by the respective electrode strips 110a, 110b, and 110c are superposed on each other according to the phase difference between the electrode strips 110a, 110b, Lt; / RTI >

Since the electrode strips 110a, 110b and 110c are formed to have the same length in the sensing section D, the electrode strips 110a, 110b and 110c And the mutual overlap of the electric fields generated in the respective electrode strips 110a, 110b, and 110c is performed in the entire sensing region D as shown in FIG.

One point (b) or another point (not shown) of the sensing section D indicates the position of sensing the approach of the object in the sensor strip section 110. Each electrode strip 110a, 110b, The electric field superposition effect for sensing the object 500 occurs at the corresponding position of the object 500a.

FIG. 6 is an electric field superposition scheme between electrode strips in an object proximity sensing apparatus according to an embodiment of the present invention. FIG.

When two or more electrode strips 110a, 110b and 110c are formed and arranged so as to have mutual length differences and a predetermined phase difference is generated between the electrode strips 110a, 110b and 110c, as shown in FIG. 6 The electric field is superposed between the electrode strips 110a, 110b and 110c and the detection distance for sensing the approach of the object 500 through the sensor strip portion 110 is increased.

Figs. 6A to 6C are simplified views showing changes in the electric field range according to the oscillation frequency period. The maximum distance (range) of the superimposed electric field is set by each of the electrode strips 110a, 110b and 110c (Range) of each electric field.

For example, the electric field a1 formed by the electrode strip 110a on the left side in FIG. 6 (a) is the largest, the electric field b1 formed by the middle electrode strip 110b, and the electric field c1 formed by the right electrode strip 110c And the combined electric field a1 + b1 + c1 shows the electric field further increased in the overlapping portion including each electric field.

The difference in the magnitude of the electric field can be understood from the fact that when the waveform applied to each of the electrode strips 110a, 110b, and 110c is a sinusoidal wave, a difference in amplitude occurs according to a phase difference even in the same waveform.

FIG. 6 is a schematic diagram created to help understand the overlap of the electric field generated by each of the electrode strips 110a, 110b, and 110c. The representation of each electric field is shown by the respective electrode strips 110a, 110b, and 110c It does not limit the shape of the generated electric field.

Meanwhile, the electrode strips 110a, 110b, and 110c may have different branch positions for forming a difference in length.

7 is a schematic view of an electrode strip according to another embodiment of the present invention.

For example, as shown in FIG. 7, three or more electrode strips 110a, 110b, and 110c may be provided, and each of the electrode strips 110a, 110b, (B) of the sensing section (D) are different from each other in length from the power supply point (a) to the power supply point (a).

For example, the length of the electrode strip 110a from the power applying point (a) to one point (b) of the sensing section (D) is the shortest distance of a-b1, The length of the electrode strip 110b to a point b of the sensing period D is determined by the shortest distance a-b2, the shortest distance from the power application point a to one point b of the sensing region D, The length of the electrode strip 110c is the shortest distance of a-b3, and the lengths of the electrode strips are different from each other.

The length difference structure between the electrode strips 110a, 110b, and 110c according to the respective embodiments may be different from that of the electrode strips 110a and 110b without using a separate element (e.g., a capacitor, an inductor, And 110c, respectively, so that a detection error due to a dead point can be prevented.

Therefore, it is possible to prevent a detection error due to a dead point even when the power input frequency which is difficult to use the phase change element is a high frequency of several GHz or more, and to increase the detection distance due to the electric field superposition of the electrode strips 110a, 110b and 110c Lt; / RTI >

8 is a perspective view of a sensor strip according to an embodiment of the present invention.

The sensor strip according to an embodiment of the present invention includes two or more electrode strips 110a, 110b, and 110c that are variable in capacitance value according to the approach of the object 500 and branch from one power application point (a) Wherein the at least two electrode strips (110a, 110b, 110c) form an object sensing section (D) extending parallel to each other along the longitudinal direction, and the at least two electrode strips (110a, 110b, 110c) The lengths from one point b to the power application point a of the sensing section D are formed to have mutual differences.

The sensor strips are configured such that each of the electrode strips 110a, 110b, 110c, and 110 'is disposed within the dielectric with a longitudinal spacing c. In a similar manner to the sensor strip 110 according to the above- And therefore, detailed description will be omitted.

The sensor strip may be applied as a component of an object proximity sensing device, such as a safety system, to prevent mutual collision between the object 500 and a moving object (e.g., a movable platform of a vehicle). For example, when the control unit determines that the sensor strip is disposed close to the moving direction of the moving object, and the control unit determines that the object 500 is close to the sensor strip, a safety management signal is generated, Can be prevented from colliding with each other.

At this time, phase differences are generated between the electrode strips 110a, 110b, and 110c provided on the sensor strips depending on the distance difference, so that the dead points do not overlap with each other and the detection distance of the object is increased due to the overlap of the electric field.

Accordingly, since the approach of the object 500 can be detected quickly and accurately from a long distance, the sensor strip can be provided on the moving object to prevent the object 500 from colliding with the moving object even when moving along with the moving object.

Although the present invention has been described with reference to the preferred embodiments thereof with reference to the accompanying drawings, it will be apparent to those skilled in the art that many other obvious modifications can be made therein without departing from the scope of the invention. Accordingly, the scope of the present invention should be interpreted by the appended claims to cover many such variations.

100: sensing part 110: sensor strip part
110a, 110b, 110c: first electrode strip 110 ': second electrode strip
200: control unit 500: object

Claims (9)

Wherein the at least two electrode strips form an object sensing section extending in parallel to each other along the longitudinal direction of the electrode strips, Wherein the at least two electrode strips have different lengths from one point of the sensing section to the power application point;
A sensing unit sensing a change in capacitance value of the sensor strip unit; And
And a controller for determining whether the object is accessed using an electrical signal corresponding to a change in the capacitance value sensed by the sensing unit,
And detects a change in capacitance value in a state of having a phase difference between the electrode strips at one point of the object detection interval.
The method according to claim 1,
The electrode strip may have three or more electrode strips,
Wherein each of the electrode strips is formed in such a manner that the lengths from one point of the sensing section to the power applying point are different from each other by branching sequentially from one power applying point.
The method according to claim 1,
The electrode strip may have three or more electrode strips,
Wherein each of the electrode strips is formed such that at least two strips are branched at the same time from one power supply point and the lengths of the electrode strips from the power supply point to the start point of the sensing interval are different from each other, Sensing device.
The method according to claim 1,
Wherein a length difference between the electrode strips is smaller than a maximum length difference obtained based on the following equation (1).
[Equation 1]

(d _max : Maximum length difference [m], c: Speed of light [m / s], f: Power input frequency applied to sensor strip [Hz]
The method according to claim 1,
The sensor strip portion includes:
A first electrode strip formed with at least two electrode strips disposed thereon, and a second electrode strip disposed opposite to the first electrode strip in a direction perpendicular to the first electrode strip, And a second electrode strip provided so as to hold the object.
6. The method of claim 5,
Wherein the first electrode strip forms a positive electrode and the second electrode strip forms a ground or negative electrode.
The method according to claim 1,
The sensing unit includes:
An RF oscillator connected to the sensor strip portion and varying an oscillation frequency according to a change in capacitance value of the sensor strip portion;
And a phase locked loop unit connected to the RF oscillator and controlling the RF oscillator to maintain a reference oscillation frequency when the oscillation frequency of the RF oscillator changes from a reference oscillation frequency in accordance with a change in the capacitance value The object proximity sensor.
The method according to claim 1,
Wherein the sensing of the change in the capacitance value is performed in a state where electric fields generated by the respective electrode strips are superimposed on each other at one point of the object sensing period.
Wherein the at least two electrode strips form an object sensing section extending in parallel to each other along the longitudinal direction of the electrode strips, And the two or more electrode strips are formed such that the lengths from one point of the sensing section to the power application point are different from each other.

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