CN1867837A - Proximity sensor - Google Patents

Abstract

A micro wave oscillation unit (30) has an output oscillation function capable of automatically adjusting the frequency of a micro wave emitted from an antenna. The antenna is formed by a conductive member consisting of external panels (11-14) and emits a micro wave of a particular frequency having a wavelength sufficiently short as compared to the size of the conductive member consisting of the external panels (11-14). The micro wave oscillation unit (30) can detect a person or a thing as a detection object (27) of detection regions (11A-14A) set outside the external panels (11-14) attached as a single body or in a separable way to a vehicle (1).

Description

Proximity sensor

Technical field

The present invention relates to proximity sensor, it detects the specific electromagnetic radiation space of using in status detection closely variation also relates to the proximity sensor that uses microwave.

Background technology

Existing general proximity sensor described in patent documentation 1, is made of following mechanism: oscillating mechanism; Resonance mechanism, the higher harmonic resonance of the oscillation frequency of itself and described oscillating mechanism; Detecting electrode, it is connected described resonance mechanism; And testing agency, its signal that detects based on the electrostatic capacitance change between described detecting electrode and the detected material changes.Described as used herein oscillating mechanism is the loop with the assigned frequency vibration of predesignating.In addition, by the resonance mechanism that LC series resonance loop constitutes, constitute the loop with resonance such as the higher hamonic wave of oscillation frequency, and do not resonate with oscillation frequency.

Therefore, if object near detecting electrode, the electrostatic capacitance change between body surface and the detecting electrode then, thereby, change in detection signal.Change by the signal that monitors this detection signal, can detect the approaching of object.

In this proximity sensor,, set in the mode that becomes value when consistent and increased the value of ormal weight, and improve at temperature variation or long-term characteristic with resonant frequency by initial value with electrostatic capacitance.

In the existing proximity sensor of record, because the electrostatic capacitance between inspected object and the detecting electrode, therefore the size owing to people or object forms the result who detects apart from different, might cause the maloperation of accuracy of detection difference in patent documentation 1.In addition, also exist detected object around rain or the many problems of maloperation that cause of the variation of humidity.Also have, under the situation of the electric conductivity main body that this proximity sensor is provided in vehicle, because the electrostatic capacitance between the metal master ground wire of detection detecting electrode and vehicle, therefore, be difficult to distinguish this on-off action and be clipped in this situation etc., in the reality, also there is the problem that is difficult to detecting electrode is arranged on the metal master of vehicle.

On the other hand, as the loop of using the oscillation frequency from about the 200KHz～1MHz of antenna output, known have iron ear bright (theremin) loop.This bright loop of iron ear, the variation of the oscillation frequency with people's hand during near the antenna of the part of oscillator and its oscillator is converted to the variation of sound and uses as electronic musical instrument.This bright loop of iron ear if use as the proximity sensor that uses electromagnetic wave to detect, then can be detected the variation of the distance variation as frequency.

Yet, in the general bright loop of iron ear, if the centre has human body, or near have human body, then in the part of oscillator, the people causes that the amount that condenser capacitance changes causes frequency change, the influence of people's size is big, supposes to change the material of object, increases the size of object, concerning proximity sensor, can not improve precision.Also have, in the in-plant detection of human body etc.,, become impossible thereby detect because that the electrostatic capacitance between antenna and the human body plays a part is big.

Therefore, in the technology of patent documentation 2, the microwave of wide band frequency modulation has been carried out in radiation, the signal that the reflection of this microwave is received and the signal of transmission carry out mixing, detection is from the reflection wave of the microwave of the antenna radiation of the frequency of propagation distance with corresponding microwave and phase place, and from frequency mixer output beat signal, described beat signal is based on from emitting to the time that receives till the reflection wave, and computing is apart from the distance of object.As this signal Processing, by two reference signals of beat signal with the quadrature of the frequency of distance with corresponding regulation, obtain and take advantage of the calculation summation, obtain the ratio of two summations, by this signal than the phase place of obtaining corresponding beat signal, then, will to the time of signal that should phase place go up or the space on variation, be scaled the temporal variable quantity of object distance or the variable quantity on the space.

Thus, under the situation of using electric wave such as microwave or cement bond logging set a distance, its beamwidth is not subjected to the hole of reflecting body or the influence of small concavo-convex distribution, expands the degree that can stablize the signal that obtains representing mean distance to, therefore, need not averaging processing separately.In addition because the processing of carrying out received signal that can be at a high speed, therefore, have can high speed detection feature.

Patent documentation 1: the spy opens the 2001-55852 communique

Patent documentation 2: the spy opens the 2001-4741 communique

Like this, detecting from the reflection of the microwave of antenna radiation, and by emitting to the time that receives till the reflection wave, computing is in the common Continuous Wave with frequency modulation mode (FMCW mode) of the distance of object, for example, in order to amplify frequency deviation (frequency sweep (sweep)), guarantee the sharpness of frequency, and have to use high frequency.

Particularly, in patent documentation 2, in the Continuous Wave with frequency modulation mode of record,, the sweep frequency time is made as 3ms, then can passes through in-plant beat period, infer and detect distance if sweep frequency is made as 1.5GHz.But, owing to can not measure absolute distance, therefore, have to and, utilize the modes such as triangulation of laser with for example.Its result is restricted on the maximization of cost, device, reflecting surface etc., exists to be difficult to realize problem at a low price.

In addition, in known two frequency continuous wave modes utilizing Doppler effect,, then can not detect distance in theory if the detected object object in electromagnetic wave radiation space stops.In addition, in the pulsed mode Doppler mode, needing pulse width is width about 1ps, and existence can not realize problem at a low price.

Summary of the invention

Therefore, the present invention carries out in order to remove above-mentioned existing problem, so that following proximity sensor to be provided is problem, that is: this proximity sensor, not since detected object around rain or the environmental change that causes such as the variation of humidity or the maloperation due to the deterioration all the year round, can miniaturization, cheapness and high precision for example, also can detect even detected object is static, and can make the detection speed high speed, can also be used in the structure that the metal by vehicle etc. constitutes.

In the proximity sensor of technical scheme 1, comprise by surveyed area that constitutes with the electromagnetic wave of humidity, temperature, air pressure change radiation space and the space that forms by electroconductive member, or be present in described surveyed area and the detected object in the space that forms by described electroconductive member and form microwave circuit.The detected object of this surveyed area and the described microwave circuit that forms by electroconductive member, if have detected object at this surveyed area, then bring into play the spread state variation of the electroconductive member of function as antenna, therefore, can be by variation as the characteristic value of the radio wave propagation of each wavelength components (frequency content) of this spread state, the existence that detects detected object is whether.That is, if having detected object at surveyed area, when then comparing detected object and not existing, the spread state of the microwave of resonance circuit changes, and therefore, by this is detected, the existence that can judge detected object whether.

Also have, bring into play the size of the electroconductive member of function relatively as antenna, make the microwave radiation of abundant weak point, be present in the microwave circuit of the existence of the detected object in the described surveyed area with described electroconductive member detection as the variation of the characteristic value of radio wave propagation, can on described electroconductive member, set a plurality of resonant frequencies, in other words, can on described electroconductive member, form a plurality of standing waves, therefore, can improve the accuracy of detection of detected object.

The proximity sensor of technical scheme 2, usefulness UWB (Ultra Wide Band) oscillator is supplied with from the wide band frequency of the microwave of the electroconductive member radiation of bringing into play function as antenna.Be used to constitute the microwave circuit of the resonance circuit between the detected object that is formed on described electroconductive member and described surveyed area or existence, a plurality of resonant frequencies of supplying with by the UWB oscillator become resonance state, if but other a plurality of frequencies cause reflection or absorb, and have detected object at surveyed area, then the spread state of the frequency of supplying with from the UWB oscillator thus changes, therefore, the existence that can detect detected object whether.That is, resonance circuit by to its detection, and can be judged detected object because the spread state of the frequency of supplying with from the UWB oscillator changes.

Difference according to the spread state of the frequency of supplying with from the supply terminals of described UWB oscillator detects the variation of described surveyed area.The microwave circuit that forms by the detected object and the described electroconductive member of described surveyed area, a plurality of resonant frequencies of supplying with by the UWB oscillator become resonance state, if but other a plurality of frequencies cause reflection or absorb, and have detected object at surveyed area, then the spread state of the frequency of supplying with from the UWB oscillator thus changes, therefore, the difference of the characteristic value of radio wave propagation that can be by its each wavelength components (frequency content), and the existence that detects detected object is whether.That is, if having detected object at surveyed area, then therefore microwave circuit, to its detection, thereby can judge detected object owing to the spread state of the frequency of supplying with from the UWB oscillator changes.At this, above-mentioned UWB oscillator, with the fully short frequency of the size of the relative electroconductive member integral body of wavelength, with described electroconductive member as antenna, resonance circuit between the detected object that is formed on described electroconductive member and surveyed area or exists is supplied with electromagnetic wave (energy), the characteristic value difference of the radio wave propagation of each wavelength components by this supply is known the existence of detected object.

Thereby, UWB (Ultra Wide Band) is meant under the condition of not using carrier wave, the set of the spike train that pulse width is very narrow is used as the broadband frequency, under the condition of not modulating, transmit the technology of signal, certainly, compare the frequency of using in the existing communication technology, the frequency bandwidth of occupying.U.S. FCC (Federal Communications Committee) has descended definition to UWB, in view of the above, and expression frequency-output characteristics as shown in Figure 6.

In Fig. 6, Δ f/fc=2 (fH-fL)/(fH+fL) 〉=20%,

Perhaps, be defined as Δ f=fH-fL 〉=500MHz.Has the equal meaning of above-mentioned definition at the UWB that implements under the situation of the present invention.

Also have, be installed in mounting object and the electroconductive member that constitutes, be not limited to surface plate with integral type or separable mode, can be for being processed into the shape of band shape, wire-like members.

Also have, the supply terminals of electroconductive member is set on the point of roughly inferring by emulation or actual measurement.Also have, reference oscillator is an oscillator of determining the mixing frequency, and the oscillator of common microwave gets final product.

The detection of the variation of the characteristic value of the described radio wave propagation of the proximity sensor in the technical scheme 3, by using frequency mixer and identification circuit to carry out, behind the directional coupler and bandpass filter of the supply terminals of described frequency mixer input by being connected the UWB oscillator, the frequency and the frequency reducing frequency conversion of the described electroconductive member that amplifies with enlarger are carried out mixing with frequency, described identification circuit detects the variation of described surveyed area by the frequency through described frequency mixer.

Under the non-existent situation of detected object, the change hardly of the characteristic value of the radio wave propagation of characteristic frequency.That is, if do not have detected object at surveyed area, then become resonance state by a plurality of resonant frequencies from the supply of UWB oscillator, still a plurality of frequencies by other cause reflection or absorption, determine in the lump from the spread state of the frequency of UWB oscillator supply.But if having detected object at surveyed area, then the characteristic value of the radio wave propagation of each frequency content of supplying with from the UWB oscillator thus changes, thereby the existence that can detect detected object whether.At this moment, from the microwave of electroconductive member radiation, extract as the frequency that each wavelength components (frequency content) of the influence that is subjected to detected object is eliminated noise via bandpass filter, and then, with the frequency mixing of this and reference oscillator, and the frequency reducing frequency conversion, become the frequency figure of each frequency of this detection.The frequency figure of each frequency of this detection compares with known frequency figure, can detect distance, size of detected object etc. thus.

At this, detect the identification circuit of the variation of described surveyed area, also can use FFT (the high speed fourier transform: fast fourier transform), the frequency content based on spread state is carried out frequency resolution, judge the distribution of each frequency content that is used for frequency resolution.In addition, also can use F-V converter (frequency-voltage converter).

In addition, directional coupler is connected between UWB oscillator and its supply terminals, and the bandpass filter side that has to the supply terminals that is connected electroconductive member imports, and shields its reverse function that moves.

The detection of the variation of the characteristic value of the described radio wave propagation of the proximity sensor in the technical scheme 4, by using frequency mixer and identification circuit to carry out, described frequency mixer is from the described frequency that is subjected to the electricity point to import described electroconductive member of one or more separate configurations, and input frequency reducing frequency conversion is carried out mixing with frequency, described identification circuit detects the variation of described surveyed area by the frequency through described frequency mixer.

If detected objects such as people are near near the electroconductive member, then for example electric field detected object in electromagnetic wave radiation space reflects or absorbs, and the characteristic value of each frequency changes.At this moment, the characteristic value of the radio wave propagation of each wavelength components (frequency content) of the detected object influence in electromagnetic wave radiation space, extract as the frequency of eliminating noise through bandpass filter from the electricity point that is subjected to of the more than one separate configurations of described electroconductive member, frequency mixing with this and reference oscillator, and the frequency reducing frequency conversion, obtain the frequency figure of each frequency of this detection.The frequency figure of each frequency of this detection and known frequency figure compare, and can detect distance, size of detected object etc. thus.Particularly, by the electric point that is subjected to two above separate configurations of frequency of electroconductive member is set, can use the state of the characteristic value of a plurality of radio wave propagations.

For example, under the big situation of the size of electroconductive member, might detect sensitivity and descend, its reason is from supply terminals radiation electromagnetic wave, and the distance when returning (being subjected to electric point) once more is elongated, therefore, and signal attenuation.Thereby, by a plurality of electric points that are subjected to are set, can further improve sensitivity, and, can guarantee the S/N ratio.

The proximity sensor of technical scheme 5, by between the detected object of described electroconductive member and described surveyed area, forming resonance circuit, variation according to the spread state of the frequency of supplying with from the supply terminals of described UWB oscillator, test example as, the variation of described detected object and translational speed are as the variation of frequency figure and the Doppler shift of each frequency.

If in electromagnetic wave radiation space is the resonance circuit that forms microwave between surveyed area and the electroconductive member, supply with microwave from above-mentioned UWB oscillator to this, the resonance circuit that is formed by the detected object and the electroconductive member of this surveyed area then, a plurality of humorous resonance rate of supplying with by the UWB oscillator becomes resonance state.But, cause reflection or absorb by other a plurality of frequencies, and have detected object, when then the spread state of the frequency content of supplying with from the UWB oscillator is thus compared detected object and do not existed at surveyed area, change, the existence that therefore can detect detected object whether.In addition, can also detect the translational speed of detected object by the Doppler shift of each frequency.For example, if detected objects such as people near near the electroconductive member, then electromagnetic electromagnetic wave detected object reflection or absorb, spread state changes, the change in location of surveyed area.At this moment, the frequency that detects from electromagnetic wave radiation space has each wavelength components of the influence that is subjected to detected objects such as people, therefore, shows as the variation of the frequency figure of corresponding spread state.In identification circuit, can be with the variation of the frequency figure of electroconductive member as the basis, the frequency figure of the pace of change that detects and the Doppler shift that comprises each frequency and known in advance reference frequency figure are compared, according to this reference frequency test pattern distance, size, translational speed etc.

Promptly, the UWB oscillator of output microwave is a broadband, therefore by electromagnetic wave radiation space be surveyed area and as the electroconductive member of antenna performance function in the definite resonance circuit, a plurality of each resonant frequency of supplying with by the UWB oscillator become resonance state, other a plurality of frequencies cause reflection or absorb that the characteristic value of their radio wave propagation changes.Thereby, if having detected object,, when comparing detected object and not existing, change then from the characteristic value of a plurality of frequencies of UWB oscillator radiation at surveyed area, therefore, whether and translational speed the existence that can detect detected object.

Also have, the supply terminals of electroconductive member is set at the point of roughly inferring by emulation and actual measurement.Also have, reference oscillator is an oscillator of determining the mixing frequency, can be the oscillator of common microwave.

The variation of the described detected object of the proximity sensor in the technical scheme 6 and the identification of translational speed, by using frequency mixer and identification circuit to carry out, described frequency mixer imports the frequency of described electroconductive member, and input frequency reducing frequency conversion is carried out mixing with the frequency of frequency and described UWB oscillator, described identification circuit is by through the frequency of described frequency mixer, detects the variation of described detected object and translational speed as the variation of frequency figure and the Doppler shift of each frequency.

At this, if in electromagnetic wave radiation space is the resonance circuit that forms microwave between surveyed area and the electroconductive member, supply with microwave from above-mentioned UWB oscillator to this, the resonance circuit that forms by the detected object and the electroconductive member of this surveyed area then, a plurality of resonant frequencies of supplying with by the UWB oscillator become resonance state, but so that other a plurality of frequencies cause reflection or absorb that the characteristic value of the radio wave propagation of these a plurality of frequencies changes.At this moment, the frequency that detects from electromagnetic wave radiation space has the characteristic value of wavelength components (frequency content) radio wave propagation of the influence of detected object, therefore, and the translational speed that can detect this detected object by the pace of change or the frequency displacement of frequency figure.In identification circuit, can be with the speed of the frequency graphic change of electroconductive member as the basis, the pace of change of the frequency figure that detects and the pace of change of known reference frequency figure are in advance compared, according to this reference frequency test pattern distance, size, translational speed etc.

The common UWB oscillator of this identification circuit is that the variation of characteristic value of the radio wave propagation of surveyed area is discerned as the variation of frequency figure to electromagnetic wave radiation space, the frequency figure that detects and reference frequency figure corresponding to known distance, size, translational speed etc. are compared, thus, detect distance, size, translational speed etc., can constitute by analog loopback or digital loop.Specifically, constitute with storer etc. by F-V converter, FFT etc.

In the resonance circuit of the microwave of the detected object that comprises described surveyed area of the proximity sensor in technical scheme 7,, then on described electroconductive member, produce some standing waves if produce microwave.By the relation between this surveyed area and the described electroconductive member, from the specific frequency of the corresponding some standing waves of described electroconductive member.Therefore, even oscillation frequency is radiated as electromagnetic wave from electroconductive member, under the non-existent situation of detected object, electromagnetic wave radiation space does not change yet, and therefore, the frequency variation of the oscillation frequency of this moment depends on the condition of work of actual machine.Yet, if near or the existence of the close electroconductive member of detected object, the reflection of electric field detected object or the absorption in electromagnetic wave radiation space, the position that the electromagnetic wave of surveyed area radiates the space changes.

For example, bringing into play the electroconductive member of function and the space between the detected object as antenna, form the loop of microwave, a plurality of oscillation frequency from electroconductive member output are exerted an influence, detected object reflection or absorption, thus, increase frequency of amplitude, reduce frequency of amplitude and each frequency changes.There is two or more frequencies simultaneously in the variation of this each frequency, but in fact becomes the frequency state of both sums, as the frequency content of resonance effect, is changed to a frequency.By extracting this frequency change, detect detected object.

At this, above-mentioned microwave oscillation portion, with the fully short frequency of the size of the relative electroconductive member integral body of wavelength, the microwave of described electroconductive member as antenna is positioned on the described electroconductive member, radiate this microwave from described electroconductive member, and the frequency of the microwave that should radiate changes the oscillation frequency in resonance circuit according to the state in electromagnetic wave radiation space.

Proximity sensor in the technical scheme 8 has: the output oscillator, and it supplies with the frequency that generates from the microwave of described electroconductive member radiation; Frequency mixer, the frequency of the microwave that it will obtain from described electroconductive member and the frequency mixing that obtains from reference oscillator, and detect assigned frequency; Bandpass filter, it only selects specific frequency from the frequency with described frequency mixer mixing; And feedback system, it gives described output oscillator by the frequency feedback through described bandpass filter.

Electromagnetic wave radiation space at the resonance circuit of described microwave oscillation portion, generation has the frequency that will obtain from described electroconductive member and the frequency mixing of reference oscillator, and by the frequency extraction of bandpass filter as the change difference, by exist (output of VSWR measuring appliance) of this standing wave, feed back to the frequency of output oscillator via feedback system.

Thereby, from exporting oscillator via the microwave of frequency mixer from electroconductive member output, radiate the resonance circuit that forms microwave between the detected object that the space is surveyed area and electroconductive member or existence at electromagnetic wave, become the corresponding spread state of state that radiates the space with the electromagnetic wave of this surveyed area.At this, even radiate the microwave of vibration from electroconductive member, under the non-existent situation of detected object that is causing reflection or absorbing, the characteristic value of specific frequency does not change, and therefore, the frequency variation of resonance circuit does not take place.

Yet, if detected object near near the electroconductive member, perhaps detected object exists, then electromagnetic electric field, the magnetic field detected object from the electroconductive member radiation reflects or absorbs, thereby, spread state, i.e. the position in the electromagnetic wave of surveyed area radiation space changes.

Thereby, if having detected object in the electromagnetic wave that constitutes by surveyed area radiation space, then based on and the electroconductive member that detects before between the characteristic value of the distinctive frequency determined change.The characteristic value of each frequency that detects when comparing position probing object in electromagnetic wave radiation space and not existing, changes.The signal of this variation is measured the signal corresponding with distance, size etc. in advance as reference signal, judge its character, the signal of this reference signal and described variation relatively, thus, infer distance, size etc. or Figure recognition, can detect distance, size etc. by stipulating.

At this, the output oscillator of output microwave, having by electromagnetic wave radiation space is surveyed area and the radiation frequency determined as the electroconductive member of antenna performance function, so is the excitation microwave oscillator that can be controlled oscillation frequency by the external world.Also have, the supply terminals of electroconductive member is the point of roughly inferring by emulation and actual measurement, and in addition, the radiation frequency is set too.So reference oscillator is an oscillator of determining the mixing frequency, can be the oscillator of common microwave.

And then above-mentioned frequency mixer can be with frequency (f) that obtains from above-mentioned output oscillator and frequency (fo) mixing that obtains from reference oscillator, as mixing frequency (mf+nfo; Wherein, m, n be-∞～+ integer of ∞).And then above-mentioned bandpass filter is only extracted one from above-mentioned mixing frequency (mf+nfo), and for example, frequency (f+fo) can be carried out signal Processing and be got final product.Certainly, implementing to select any of above-mentioned mixing frequency (mf+nfo) under the situation of the present invention.

The described microwave oscillation portion of the proximity sensor in the technical scheme 9 by the standing wave through the frequency of described bandpass filter, and discerns the variation of described surveyed area.

That is, the standing wave based on the characteristic value of the distinctive frequency of determining between the electromagnetic wave that is made of surveyed area radiation space and the electroconductive member produces at electroconductive member.And the VSWR of the frequency of the process bandpass filter of this detection (Voltage Standing Wade Ratio: voltage standing wave ratio (VSWR)), compare, and changes by the spread state when not existing with the position probing object that radiates the space at electromagnetic wave.The signal of this variation, signal that will be corresponding with distance, size etc. is measured as reference signal in advance, judges its character, relatively the signal of this reference signal and described variation, infer distance, size etc. or Figure recognition thus, can detect distance, size etc. by stipulating.

Also have, the value after the absolute value maximum with voltage that described VSWR is meant the standing wave that the interference by the capable ripple of characteristic frequency and reflection wave is produced removes with the absolute value of minimum voltage is not having reflex time, and the value of minimum is " 1 ".

Above-mentioned identification circuit, discerning above-mentioned electromagnetic wave radiation space by VSWR is the variation of the spread state of surveyed area, with VSWR with compare corresponding to the benchmark of known distance, size etc., detect distance, size etc. thus, constitute by mimic channel or digital circuit.

Proximity sensor in the technical scheme 10 connects output oscillator from microwave to described electroconductive member that supply with, and supplies with electromagnetic wave to described electroconductive member.Therefore, in the surveyed area in the outside that is set in described electroconductive member or when having detected object, between the detected object of described electroconductive member and described surveyed area, form the quasi loop that is regarded as the cavity resonance loop, obtain the frequency of this quasi loop from described output oscillator, detect the variation of the variation of the characteristic value whether detected object of described surveyed area exist as the oscillation frequency of described output oscillator.

With described electroconductive member during as the antenna radiated microwaves, if detected object is near the zone of detecting this microwave, or exist, then form electroconductive member and detected object the quasi loop that is regarded as the cavity resonance loop as antenna performance function, be equivalent to from the wavelength components (frequency content) that detects the distance of object, because this detected object becomes antenna, and between the electroconductive member as antenna performance function antenna taking place mutually combines, a plurality of oscillation frequency from electroconductive member output are exerted an influence, cause the reflection or the absorption of detected object, cause the variation of each frequency thus, making becomes the increase frequency of amplitude, the frequency of amplitude contraction.Therefore, by the skew (frequency displacement) that detects the oscillation frequency of exporting oscillator, the amplitude of characteristic frequency, can detect detected object.The detection of detected object can detect the skew, the equifrequent variation of oscillation amplitude change of this frequency of the oscillation frequency of output oscillator, the existence that can detect detected object whether, the translational speed of detected object, the size of detected object etc.

At this, above-mentioned mounting object is meant the mounting object thing of proximity sensor, in addition, but above-mentioned electroconductive member is so long as get final product mounting object integral type or separable electric conductor, and basic structure can be one dimension tectosome (mainly being the tectosome that only has length direction), two-dimensional structure body (mainly being the tectosome that only has area), three-dimensional structure body.

Above-mentioned output oscillator is meant the oscillator of the microwave of the resonant condition that is easy to introduce outgoing sides such as dielectric oscillator or LC oscillator.And, send the reference oscillator of the microwave of the temperature that constitutes by characteristic frequency, be to can't help from externalities, and the oscillator of the stable microwave of the oscillation frequency of change itself.

In addition, above-mentioned surveyed area is determined by the wavelength output of electroconductive member and microwave, but is set in usually in the 50cm in the scope in the outside that is set in above-mentioned electroconductive member, preferably sets at 30cm with interior distance arbitrarily.

Also have, as mentioned above, from the electroconductive member radiated microwaves time, if detected object near this place, then forms electroconductive member and detected object each other as the quasi loop that is regarded as the cavity resonance loop of antenna performance function.At this, in the present invention, to the electromagnetic wave from exporting oscillator output and radiating from electroconductive member, detected object reflection or the 2 dimensional region that absorbs are above-mentioned surveyed areas, in addition, adopt the three dimensions of the radiated microwaves of above-mentioned surveyed area is exactly electromagnetic wave radiation space three-dimensionally.

Proximity sensor in the technical scheme 11, the outgoing side at described output oscillator has: frequency mixer, it will be from the frequency of described output oscillator output and the frequency mixing that obtains from reference oscillator; Identification circuit, it is by selecting the frequency with described frequency mixer mixing, and the signal of the frequency of detection, and identification is set in the variation of the interior detected object of the surveyed area in the outside of described electroconductive member.

With described electroconductive member during, if detected object near this place or exist, then forms electroconductive member and detected object each other as the quasi loop that is regarded as the cavity resonance loop of antenna performance function as antenna performance function and radiated microwaves.At this, from the microwave of exporting oscillator output and radiating from electroconductive member, detected object reflection or absorption.The existence of this detected object causes from the electromagnetic electric field detected object reflection of electroconductive member radiation or absorbs, and this influence shows as the variation of the output frequency of output oscillator.Export the variation of the output frequency of oscillator by this, can be in frequency mixer and the frequency mixing and the frequency reducing frequency conversion that obtain from reference oscillator, confirm through the skew of the frequency of described frequency mixer, the oscillation amplitude change of this frequency by identification circuit, thus, the existence that detects detected object whether, the translational speed of detected object, the size of detected object etc.

At this, above-mentioned mounting object, output oscillator, surveyed area are identical with the situation of technical scheme 10, and in addition, it is also identical that electromagnetic wave radiates the space.Above-mentioned frequency mixer is so long as with frequency (f) that obtains and frequency (fo) mixing that obtains from reference oscillator, and as the mixing frequency (mf+nfo of frequency reducing frequency conversion; Wherein, m, n be-∞～+ integer of ∞) frequency mixer get final product.And then, above-mentioned bandpass filter only be extracted in above-mentioned frequency mixer mixing the mixing frequency (| f+fo| or | f-fo|), can be for before wave detector, carrying out signal Processing or by in the bandpass filter of carrying out signal Processing after the wave detector any one.And then, above-mentioned identification circuit, usually detect above-mentioned electroconductive member and be the variation of surveyed area as the variation of oscillation frequency (skew of the frequency by frequency mixer or the oscillation amplitude change of this frequency etc.), with compare corresponding to the skew as the frequency of benchmark of known distance, size etc., oscillation amplitude change of this frequency etc., detect distance, size of detected object etc. linearly.The skew of the frequency of this frequency mixer of process, the oscillation amplitude change of this frequency can also detect translational speed by importing time factor.This identification circuit is made of analog loopback or digital loop and gets final product.Specifically, constitute with storer etc., have the mapping graph of the skew that stores by the frequency of described frequency mixer, the oscillation amplitude change of this frequency etc., and compare with the information of this mapping graph and judge by F-V converter, FFT etc.In addition, if the frequency by frequency mixer is limited its frequency, then can also be by the having or not of this frequency, by and the threshold value of regulation between relation obtain the output of two values.

The described output oscillator of the proximity sensor in the technical scheme 12 is dielectric oscillator (DRO) or LC oscillator, therefore, is the cheap oscillator that produces microwave, and can expects true(-)running.

Proximity sensor in the technical scheme 13, by on the described electroconductive member of described microwave circuit, set supply terminals and be subjected to electric point, and amplification is from the described frequency that obtained by the electricity point, this frequency feedback is arrived described supply terminals, form the oscillation circuit that produces microwave, detect the variation of the variation of described surveyed area as the frequency that obtains from described oscillation circuit.

Therefore, when electroconductive member is sent vibration as the oscillation circuit of antenna, radiate electromagnetic wave to surveyed area from electroconductive member.This oscillation circuit is by the relation of this surveyed area and electroconductive member, and becoming has the resonance state of determining from the characteristic value of the radio wave propagation of the specific frequency state of described electroconductive member radiation.Even from the electromagnetic wave of electroconductive member radiation oscillation frequency, causing that reflection or the detected object that absorbs are not present under the situation of surveyed area, in oscillation frequency also not occurrence frequency change.But, if detected object is near the surveyed area that becomes electromagnetic wave radiation space, then between electroconductive member and detected object, form the oscillation circuit of the microwave that the characteristic value of each frequency different with spread state before changes, change from the resonant frequency state of described electroconductive member radiation.That is, if detected object near near the electroconductive member, the then electric field detected object of surveyed area reflection or absorb, thus the position in electromagnetic wave radiation space changes.By it is detected, can detect the close of detected object.At this, the variation of the frequency of detected object, the size (size of voltage) of the skew of expression frequency or the amplitude of its frequency etc.

At this, above-mentioned electroconductive member, so long as can get final product mounting object integral type or separable electric conductor, basic structure can be one dimension tectosome (mainly being the tectosome that only has length direction), two-dimensional structure body (mainly being the tectosome that only has area), three-dimensional structure body.In addition, be set in the surveyed area in the outside of above-mentioned electroconductive member, determine by the wavelength output of electroconductive member and microwave, but be set in usually in the 50cm, preferably set at 30cm with interior distance arbitrarily.And above-mentioned oscillation circuit is given described supply terminals as long as by setting supply terminals and be subjected to electric point on electroconductive member, amplify the frequency that obtained by the electricity point from described with this frequency feedback, can self-excitation sends microwave and gets final product.And then, with the variation of above-mentioned surveyed area detection as the variation of the frequency that obtains from oscillation circuit, variation with near people's the electroconductive member etc. detected object (dielectric), as the variation of the frequency that obtains from oscillation circuit and detect, can also can compare with the threshold value of regulation and judge with the variation of frequency as test pattern.

Also have, the supply terminals of above-mentioned electroconductive member and be subjected to electric point is to infer or revise the point of confirming by emulation or emulation and actual machine, in addition, oscillation frequency and surveyed area is set too.

Proximity sensor in the technical scheme 14, the oscillation circuit that is made of bandpass filter and radio-frequency amplifier will be used as the frequency of specific frequency band from the electricity point that is subjected to of electroconductive member by bandpass filter, the frequency of this frequency band is amplified with radio-frequency amplifier, and feed back to the supply terminals of electroconductive member, wherein, described bandpass filter will be subjected to frequency that the electricity point obtains as specific frequency band from described electroconductive member described, and described radio-frequency amplifier feeds back to described supply terminals after the frequency of this frequency band is amplified.Thus, form the oscillation circuit of electroconductive member as antenna, microwave is sent in self-excitation.Radiate electromagnetic wave from electroconductive member to surveyed area, by the relation of this surveyed area and electroconductive member, becoming from the specific frequency state of described electroconductive member radiation is that a plurality of frequencies become resonance state.Even from the oscillation frequency of electroconductive member radiation oscillation circuit, causing that reflection or the detected object that absorbs are not present under the situation of surveyed area, the frequency variation of oscillation frequency does not take place.

But, if wait detected object (dielectric) close, then forming the cavity oscillator of microwave between electroconductive member and the detected object the detection range people who forms electromagnetic wave radiation space, the resonant frequency state that radiates from described electroconductive member changes.That is, if detected object near near the electroconductive member, then the position in electromagnetic wave radiation space changes.Directional coupler detects the variation of characteristic value of the radio wave propagation of each frequency, and the output of this directional coupler by the frequency mixer of input frequency reducing frequency conversion with frequency, and by the frequency that obtains, is discerned the variation of described surveyed area.Also have, at this, electromagnetic wave radiation space is meant detectable surveyed area, is not the electromagnetic wave reach.

At this, above-mentioned identification circuit, to detect as the variation of the frequency that obtains from oscillation circuit as near the variation of the detected object of the electroconductive member of surveyed area, can also can compare with defined threshold and judge with the variation of frequency as test pattern.In addition, above-mentioned bandpass filter, elimination is determined the predetermined band of microwave from the noise (comprising the elimination of low frequency) of the frequency of the supply terminals taking-up of above-mentioned electroconductive member.In addition, above-mentioned frequency mixer can be frequency (f) that the supply terminals from electroconductive member is obtained and frequency (fo) mixing that obtains from oscillator, and as mixing frequency (mf+nfo; Wherein, m, n be-∞～+ integer of ∞) bandpass filter.

And then, above-mentioned identification circuit, usually with the frequency figure above-mentioned electromagnetic wave being radiated the space is that the variation of surveyed area detects as the variation of oscillation frequency, by comparing with reference frequency figure corresponding to known distance, size, translational speed etc., detect distance, size of detected object (dielectric) etc. linearly, and, can also detect translational speed by the importing of time factor as the reference frequency figure.This identification circuit can be made of analog loopback or digital loop.Specifically, constitute with storer etc. by F-V converter, FFT etc.

Proximity sensor in the technical scheme 15 is integral type or the electroconductive member that is installed in separably to described mounting object, is to open and close the switching body that is installed in vehicle freely, and is therefore simple in structure, and can cheaply make.

In the proximity sensor of technical scheme 1, detected object to the space that is present in the surveyed area that constitutes by the electromagnetic wave radiation space of following humidity, temperature, air pressure change, with described electroconductive member as the variation of the characteristic value of radio wave propagation and the microwave circuit that detects, if detected object is present in surveyed area, then the characteristic value as the radio wave propagation of each frequency of the electroconductive member of antenna performance function changes, therefore, by the variation of this characteristic value, the existence that can detect detected object whether.That is, if having detected object at surveyed area, therefore then described microwave circuit detects the variation of this propagation conditions because the spread state of microwave changes, and thus, the existence that can detect detected object whether.

Therefore,, form the big microwave circuit that influences each other in electromagnetic electric field magnetic field, propagate and this surveyed area and the corresponding frequency of this detected object in the detected object of the surveyed area that becomes electromagnetic wave radiation space and the space between the electroconductive member.Do not exist under the situation of detected object in the outside of electroconductive member, determine the characteristic value of the electromagnetic wave propagation function propagated according to antenna performance etc. in the lump.Particularly, between electroconductive member and detected object, form microwave circuit, influencing each other of electromagnetic electric field magnetic field becomes big, is not vulnerable to the influence of electrostatic capacitance of the detected object of surveyed area, therefore, compare existing electrostatic capacitance detection mode type, the influence of atmosphere such as the humidity in examined zone, temperature, water vapor, pressure ground does not detect, and device is cheap, and accuracy of detection improves.In addition, different with the detection of Doppler frequency, even the detected object of surveyed area does not move, also can detect.In addition, on electroconductive member, have a plurality of resonance frequencies that to radiate, detect the variation of its spread state, therefore, particularly do not need to scrutinize the characteristic of electroconductive member, just can implement as antenna performance function.

Thereby, can be used as the proximity sensor of the following stated, that is: do not exist along with the rain around the detected object or environmental change such as variation of temperature or along with the time deterioration causes maloperation, can miniaturization, cheapness and high precision, for example, even also can detect in that detected object is static, and, can make the detection speed high speed, can also use on the object that vehicle etc. is made of metal.

Having the UWB oscillator of described electroconductive member as the frequency of the microwave of antenna radiation of proximity sensor in the technical scheme 2 supplied with wide band microwave to described electroconductive member.At this moment, a plurality of each resonant frequency of supplying with by the UWB oscillator form resonance states, cause reflection or absorb that by other a plurality of frequencies the characteristic value of their radio wave propagation changes.By to its detection, can judge detected object.

Therefore, for example, be connected the UWB oscillator of the supply terminals of electroconductive member, the pulse of the microwave that the emission band width is wide.The pulse of the microwave of this radiation is radiated electroconductive member as antenna.At this moment, do not exist under the situation of detected object, determine characteristic values such as propagator according to antenna performance in the lump in the outside of electroconductive member.That is,,, can determine antenna performance with the characteristic value that the signal that radiates from antenna compares if consider the signal that will send from oscillator.

At this moment, microwave circuit forms the resonance circuit of the big microwave of the power that influences each other in electromagnetic electric field magnetic field, therefore, propagates the frequency of the UWB oscillator corresponding with its surveyed area and detected object thereof.Particularly, frequency of utilization is because the use of the microwave of UWB oscillator, the reciprocal influence power effect in electromagnetic electric field magnetic field is big, be difficult to be subjected to the influence of electrostatic capacitance of the detected object of surveyed area, therefore, compare existing electrostatic capacitance detection mode type, the influence of the humidity in examined zone, temperature, water vapor, pressure atmosphere such as (air pressure) ground does not detect, device is cheap, and accuracy of detection improves.In addition, different with the detection of Doppler frequency, even the detected object of surveyed area does not move, also can detect.Particularly, because the use of UWB oscillator has and can detect the variation of spread state from a plurality of resonant frequencies of electroconductive member radiation, therefore, particularly, the characteristic that does not need to scrutinize electroconductive member just can be implemented, can also standardization.So, be attached at the UWB oscillator of the supply terminals of electroconductive member, the pulse of the microwave that the emission band width is wide, therefore, there are a plurality of resonant frequencies on the electroconductive member, can access the characteristic value of a plurality of radio wave propagations, thereby can use it correctly to detect detected object.

The detection of the variation of the characteristic value of the described radio wave propagation of the proximity sensor in the technical scheme 3, by using frequency mixer, carry out with identification circuit, the directional coupler of the supply terminals of the frequency that described frequency mixer makes described electroconductive member by being connected the UWB oscillator, after bandpass filter, amplify with enlarger, and input frequency reducing frequency conversion is carried out mixing with frequency, described identification circuit is by the frequency through described frequency mixer, detect the variation of described surveyed area, therefore, the effect of in technical scheme 2, putting down in writing, if have detected object at surveyed area, then by the electromagnetic wave of supply terminals radiation from the frequency of UWB oscillator supply, the signal that turns back to supply terminals changes.The variation of this signal detects as a plurality of characteristic values.At this moment, the frequency figure of the process bandpass filter of detection is for eliminating the frequency figure of noise.In addition, directional coupler can be eliminated the reflection of supply terminals of electroconductive member to the influence of the output of UWB oscillator, from the influence to the interference of supply terminals of outside, and therefore, the UWB oscillator can stably send vibration.

The detection of the variation of the characteristic value of the described radio wave propagation of the proximity sensor in the technical scheme 4, by using frequency mixer and identification circuit to carry out, described frequency mixer is from the described frequency that is subjected to the electricity point to import described electroconductive member of one or more separate configurations, and input frequency reducing frequency conversion is carried out mixing with frequency, described identification circuit detects the variation of described surveyed area by the frequency through described frequency mixer.Therefore, the effect of in technical scheme 2 or technical scheme 3, putting down in writing, can be by the frequency figure of the process bandpass filter that detects, by known frequency figure, with corresponding to the comparing as the data of reference frequency graphics memory in advance of the distance of detected object, size etc., according to the distance of this reference frequency test pattern detected object, size etc.

In other words, return the pulse signal that is subjected to the electricity point, can regard the characteristic value of antenna performance as.Space between electroconductive member and detected object, form microwave circuit, electroconductive member and detected object have the characteristic values such as characteristic propagator of a plurality of frequencies that resonant frequency has, therefore, can be subjected to electric point by what one or two disposed respectively, the difference of the characteristic value by radio wave propagation detects situation and non-existent situation that the outside detected object of electroconductive member exists.Therefore, whether the difference of the spread state of the frequency of supplying with from the UWB oscillator changes according to the existence of the detected object of surveyed area, and therefore, the Doppler shift by each frequency detects.In addition,, can further improve the check and analysis energy by a plurality of electric points that are subjected to are set, and, can guarantee the S/N ratio.

Proximity sensor in the technical scheme 5 forms the microwave resonance loop between the detected object of surveyed area and electroconductive member, from the UWB oscillator of frequency with microwave to electroconductive member supply microwave as antenna performance function.At this moment, a plurality of each resonant frequency of being supplied with by the UWB oscillator form resonance state, are caused reflection or are absorbed by other a plurality of frequencies, and whether the characteristic value basis of these radio wave propagations exists at the surveyed area detected object and change.Therefore, if having detected object at surveyed area, then the characteristic value of the frequency of supplying with from the UWB oscillator changes.By its Doppler shift as each frequency of the characteristic value of radio wave propagation is detected, can judge the translational speed of detected object.

At this moment, and detected object as the surveyed area in electromagnetic wave radiation space between, form the loop of the big microwave of the reciprocal influence effect in electromagnetic electric field magnetic field, propagate the frequency of the UWB oscillator corresponding with this surveyed area and detected object.Particularly, frequency of utilization is by the use of wide band microwave, the reciprocal influence effect in the electric field magnetic field of magnetic wave is big, be difficult to be subjected to the influence of electrostatic capacitance of the detected object of surveyed area, therefore, compare existing electrostatic capacitance detection mode type, the influence of atmosphere such as the humidity in examined zone, temperature, water vapor, pressure ground does not detect, device is cheap, and accuracy of detection improves.In addition, the skew of spread state or pace of change by detections such as the skew of frequency figure or paces of change, can detect the distance or the translational speed of detected object.Particularly,, have a plurality of resonant frequencies that can radiate, therefore, particularly do not need to scrutinize the characteristic of electroconductive member, just can implement from electroconductive member owing to use the UWB oscillator, can also standardization.

Proximity sensor in the technical scheme 6 forms the loop of microwave between the detected object of surveyed area and electroconductive member, the UWB oscillator is to supplying with microwave as the electroconductive member of antenna performance function.At this moment, a plurality of resonant frequencies of being supplied with by the UWB oscillator form resonance state, cause reflection or absorption by other a plurality of frequencies, and the characteristic value of these radio wave propagation changes.Therefore, except the effect of technical scheme 5, the frequency that detects from electroconductive member has the wavelength components (frequency content) of detected object influence, therefore, by based on the pace of change of the frequency figure of each frequency or the skew of frequency, can detect the translational speed of this detected object.With the speed of the frequency graphic change of electroconductive member or skew as benchmark, the Doppler shift of each frequency of the frequency figure that detects is compared with the pace of change or the skew of known reference frequency figure in advance, can also advance range finding from, size, translational speed etc. according to this reference frequency figure.

Proximity sensor in the technical scheme 7, have the microwave oscillation portion of excitation from the frequency of described electroconductive member radiation, therefore, even from electroconductive member with the frequency of microwave oscillation portion as microwave radiation, under the non-existent situation of detected object that causes reflection or absorb, the also not change of frequency of microwave oscillation portion.If detected object is near near the electroconductive member, then radiating electromagnetic electric field causes reflection owing to the existence of detected object or absorbs, cause the position in electromagnetic wave radiation space to change, change the wavelength components (frequency) that is equivalent to from distance that detects object and size.By the variation of this detection, can detect distance and size.

At this moment, be between the detected object and electroconductive member of surveyed area in electromagnetic wave radiation space, form the microwave resonance loop and the microwave oscillation portion that forms, become and this surveyed area and the corresponding oscillatory regime of this detected object.Microwave oscillation portion under this oscillatory regime, the power that influences each other in electromagnetic electric field magnetic field is big, thereby, can regard the detected object of this surveyed area and the resonance circuit of the electric field intensity between the electroconductive member (magnetic field) as, not the influence of the electrostatic capacitance of the detected object in easy electromagnetic wave radiation space.

Particularly, microwave oscillation portion, form the resonance circuit of microwave between as the detected object of the surveyed area in electromagnetic wave radiation space and electroconductive member, the resonance circuit that described electromagnetic wave radiation space can be regarded as the electromagnetism intensity (magnetic field) between the antenna, it is big that the power that influences each other in electromagnetic electric field magnetic field becomes, the not influence of the electrostatic capacitance of the detected object in easy electromagnetic wave radiation space, therefore, accuracy of detection improves.In addition, use the microwave of frequency of utilization as 300MHz to 300GHz, compare existing electrostatic capacitance detection mode type, not detected by the influence ground of atmosphere such as humidity, temperature, water vapor, pressure, it is cheap that device becomes.Thereby proximity sensor of the present invention detects closely easily, and can carry out can the cheap state-detection of making, and in addition, detects differently with Doppler, even the detected object of surveyed area does not move, also can detect.

The described microwave oscillation portion of the proximity sensor in the technical scheme 8, from the microwave of output oscillator via frequency mixer output, in electromagnetic wave radiation space is to form resonance circuit between the detected object of surveyed area and the electroconductive member, becomes oscillatory regime according to the state in the electromagnetic wave radiation space of this surveyed area.At this, even radiate the microwave of vibration from electroconductive member, under the non-existent situation of detected object that is causing reflection or absorbing, the output state of specific frequency does not change, and therefore, the frequency variation of resonance circuit does not take place.

If detected objects such as people near electroconductive member neighbouring, maybe this place has detected object, then reflection takes place owing to detected object or absorbs in the electromagnetic electric field that radiates from electroconductive member, and the position in the electromagnetic wave radiation space of surveyed area changes.At this moment, the wavelength components by the detected object influence of the position in electromagnetic wave radiation space with the frequency mixing of reference oscillator, is extracted as the frequency that changes difference by bandpass filter, discerns the existence of detected object by this standing wave.

Therefore, if having detected object, do not detect the standing wave of the distinctive frequency of electroconductive member before then producing in the electromagnetic wave radiation space that constitutes by surveyed area.That is, the standing wave of detection is not compared when not existing with the position probing object that radiates the space at electromagnetic wave, changes.The signal of this variation, the signal corresponding with distance, size etc. measured as reference signal in advance, judged its character, relatively the signal of this reference signal and described variation, infer distance, size etc. or Figure recognition thus, can detect distance, size etc. by stipulating.

At this moment, proximity sensor of the present invention, and the output oscillator form the resonance circuit of microwave between as the detected object of the surveyed area in electromagnetic wave radiation space, with the specific hunting of frequency corresponding with this surveyed area and this detected object, therefore the reciprocal influence effect in electromagnetic electric field magnetic field becomes big, therefore the not influence of the electrostatic capacitance of the detected object in easy electromagnetic wave radiation space, improves accuracy of detection.

The described microwave oscillation portion of the proximity sensor in the technical scheme 9 has by the standing wave through the frequency of described bandpass filter, and discerns the identification circuit of the variation of described surveyed area.Therefore, except the effect of technical scheme 7 or technical scheme 8, the VSWR of the frequency of passing through bandpass filter that is detected compares when detected objects such as people from position in electromagnetic wave radiation space do not exist and changes.The signal of this variation, signal that will be corresponding with distance, size etc. are measured as reference signal in advance, judge its character, the signal of this reference signal and described variation relatively, thus, infer distance, size etc. or Figure recognition, can detect distance, size etc. by stipulating.

Proximity sensor in the technical scheme 10, between the detected object of described electroconductive member and described surveyed area, form the quasi loop that is regarded as the cavity resonance loop, the frequency of this quasi loop obtains from the output oscillator, and detect skew, amplitude of the oscillation frequency of described output oscillator etc., described output oscillator is supplied with the fully short frequency of the size of the described relatively electroconductive member of wavelength, makes the microwave of described electroconductive member as the antenna radiation.

Therefore, be regarded as the electromagnetic wave of electroconductive member radiation of the quasi loop in cavity resonance loop from formation, detected object reflection or absorption, its influence shows as the variation of the output frequency of output oscillator, therefore, the skew of the frequency of the oscillation frequency by detecting this output oscillator, the oscillation amplitude change of this frequency, the existence that can detect detected object whether, translational speed of detected object, the size of detected object etc.

Suppose, constitute proximity sensor even utilize the bright loop of known iron ear, under the situation for the weak point of the distance till the detected object from its wavelength, by detecting detected object as the electroconductive member of antenna performance function and the capacitance between the ground wire, the range accuracy error is owing to the size of this capacitance becomes big.But, the present invention forms and to be equivalent to detected object and as the quasi loop that is regarded as the cavity resonance loop of the microwave of the relative distance between the electroconductive member of antenna performance function, it is big that the reciprocal influence effect in electromagnetic electric field magnetic field becomes, the not influence of the electrostatic capacitance of the detected object in easy electromagnetic wave radiation space, therefore, improve accuracy of detection.In addition, be the use of 300MHz by frequency of utilization to the microwave of 300GHz, not detected by the influence ground of the atmosphere such as humidity, temperature, water vapor, pressure in electromagnetic wave radiation space, therefore, the device cheapness that becomes.

Thereby proximity sensor of the present invention detects closely easily, and can detect can the cheap closely state of making.

Proximity sensor in the technical scheme 11, between the detected object of described electroconductive member and described surveyed area, form the quasi loop that is regarded as the cavity resonance loop, the frequency mixing that will obtain the frequency of this quasi loop from the output oscillator of supplying with to described electroconductive member, obtain with reference oscillator, frequency according to this mixing is selected specific frequency, and detection, identification circuit passes through the signal of the frequency of this detection, the variation of the detected object in the surveyed area in the outside of the described electroconductive member of detection setting.

Therefore, be regarded as the electromagnetic wave of electroconductive member radiation of the quasi loop in cavity resonance loop from formation, detected object reflection or absorption, its influence shows as the variation of the output frequency of output oscillator, therefore, detect the frequency displacement of the oscillation frequency of this output oscillator, the oscillation amplitude change of this frequency at identification circuit, thus, the existence that can detect detected object whether, translational speed of detected object, the size of detected object etc.

Suppose that utilizing the bright loop of known iron ear to constitute under the situation of proximity sensor, detect detected object is brought into play the electroconductive member of function and the capacitance between the ground wire as antenna, it is big that the range accuracy error becomes.But, the present invention forms and to be equivalent to detected object and as the quasi loop that is regarded as the cavity resonance loop of the microwave of the relative distance between the electroconductive member of antenna performance function, it is big that the reciprocal influence effect in electromagnetic electric field magnetic field becomes, be difficult to be subjected to the influence of static capacity of the detected object in electromagnetic wave radiation space, therefore, improve accuracy of detection.In addition, use the use to the microwave of 300GHz, not detected by the influence ground of the atmosphere such as humidity, temperature, water vapor, pressure in electromagnetic wave radiation space as 300MHz by frequency, therefore, the device cheapness that becomes.

Thereby the present invention detects closely easily, and can carry out can the cheap status detection of making.

In the proximity sensor in technical scheme 12, with the described output oscillator of technique scheme 10 or technical scheme 11 as dielectric oscillator or LC oscillator, therefore, oscillator self cheapness, its result can make the device cheapness.

Proximity sensor in the technical scheme 13, on the electroconductive member that can install mounting object integral type or separable mode, set supply terminals and be subjected to electric point, and amplification is from the described frequency that obtained by the electricity point, this frequency feedback is arrived described supply terminals, thus, to make described electroconductive member send the oscillation circuit of microwave as antenna and be set in the variation of surveyed area in the outside of described electroconductive member with the fully short frequency of the size of the described relatively electroconductive member of wavelength, the variation by the frequency that obtains from described oscillation circuit detects.

Therefore, detected object and electroconductive member, between the detected object and electroconductive member of the surveyed area that radiates the space as electromagnetic wave, mutually as antenna performance function, they are regarded as the cavity of microwave, the microwave oscillation frequency changes according to this surveyed area and this detected object, therefore, the reciprocal influence effect in electromagnetic electric field magnetic field is big, the cavity of the electric field intensity between the electroconductive member (magnetic field) is difficult to be subjected to the influence of electrostatic capacitance of the detected object in electromagnetic wave radiation space.

Particularly, become in the microwave oscillation loop between the detected object and electroconductive member of surveyed area in electromagnetic wave radiation space, both bring into play function as antenna, thereby, the cavity that this can be regarded as the electric field intensity (magnetic field) between the antenna, the reciprocal influence effect in electromagnetic electric field magnetic field become big, are difficult to the influence of electrostatic capacitance of the detected object in examined zone, therefore, improve accuracy of detection.In addition, because frequency of utilization is the use of 300MHz to the microwave of 300GHz, compare existing electrostatic capacitance detection mode type, the influence of atmosphere such as the humidity in examined zone, temperature, water vapor, pressure ground does not detect, and therefore, it is cheap that device becomes.Also have, detect differently,, also can detect even detected object moves with the Doppler who uses microwave.

Thereby the present invention detects closely easily, and can carry out can the cheap status detection of making.

Proximity sensor in the technical scheme 14, cross on the electroconductive member that to install mounting object integral type or separable mode, set supply terminals and be subjected to electric point, and amplification is from the described frequency that obtained by the electricity point, this frequency feedback is arrived described supply terminals, thus, make described electroconductive member send microwave with the fully short frequency of the size of the described relatively electroconductive member of wavelength as antenna.At this moment, constitute the electromagnetic wave radiation space of the oscillation circuit of microwave, by will from electroconductive member be subjected to frequency that electricity point obtains bandpass filter as specific frequency band, and feed back to the radio-frequency amplifier of described supply terminals after the frequency of this frequency band amplified, form specific oscillatory regime.Be connected the described electricity that is subjected to and put between the supply terminals, and extract the directional coupler of the oscillatory regime of described oscillation circuit, detect the variation of the surveyed area in the outside that is set in electroconductive member, it is discerned with identification circuit.The oscillation frequency of this microwave under the feedback states that the direction of passage coupling mechanism produces, has frequency reducing frequency conversion frequency mixing in input, by the frequency through described frequency mixer, is judged the variation of surveyed area by identification circuit.

That is, identification circuit direction of passage coupling mechanism extracts the oscillation frequency of microwave, and the figure of this oscillation frequency is judged.The figure of the oscillation frequency of this detection and compares as the direction of passage coupling mechanism detection data with corresponding reference frequency graphics memory such as the distance of detected object, size, according to the distance of this reference frequency test pattern detected object, size etc.

At this moment, when the surveyed area detected object does not exist, if will be made as specific threshold value from the oscillation frequency of electroconductive member radiation, then the frequency variation of this threshold value relatively by detecting, the detection that can make detected object is the variation that " 1 ", " 0 " are used as the position of surveyed area.

Proximity sensor in the technology originating party case 15, can integral type or install separably and the electroconductive member formed to described vehicle, it is the switching body that vehicle open and close is installed freely, therefore, the effect of in technical scheme 1 or technical scheme 2, putting down in writing, simple in structure, and can cheaply make.

Description of drawings

Fig. 1 is the integrally-built synoptic diagram of vehicle that is equipped with the proximity sensor of embodiments of the present invention 1 and 2.

Fig. 2 is the functional-block diagram of the proximity sensor of embodiments of the present invention 1.

Fig. 3 is the functional-block diagram of the proximity sensor of embodiments of the present invention 2.

Fig. 4 is the functional-block diagram of the proximity sensor of embodiments of the present invention 3.

Fig. 5 is the functional-block diagram of the proximity sensor of embodiments of the present invention 4.

Fig. 6 is the frequency-output characteristics figure of U.S. FCC (Federal Communications Committee) to the UWB definition.

Fig. 7 is the functional-block diagram of the proximity sensor of embodiments of the present invention 5.

Fig. 8 is the functional-block diagram of the proximity sensor of embodiments of the present invention 6.

Fig. 9 is the functional-block diagram of the proximity sensor of embodiments of the present invention 7.

Among the figure, 1-vehicle, 11～14-outside plate (electroconductive member), 11A～14A-surveyed area, 121-output oscillator, 21-UWB oscillator, 22-reference oscillator, 221-output oscillator, 23-frequency mixer, 24-bandpass filter, 26-F-V converter, 27-identification circuit, 28-feedback system, 29-VSWR measuring appliance, 31-detected object, 32-wave detector, 33-S measuring appliance, 50-are regarded as quasi loop, the 60-oscillator in cavity resonance loop.

Embodiment

Below, describe with reference to the proximity sensor of accompanying drawing embodiments of the present invention.

Also have, after embodiments of the present invention 2, mark or symbolic representation and above-mentioned the embodiment 1 identical or corresponding structure part identical with embodiment 1 for common function, are omitted its repeat specification as far as possible.

(embodiment 1)

Fig. 1 is the integrally-built synoptic diagram of vehicle that is equipped with the proximity sensor of embodiments of the present invention 1 and 2, and Fig. 2 is the functional-block diagram of the proximity sensor of embodiments of the present invention 1.Fig. 6 is that U.S. FCC (Federal Communications Committee) is to UWB (Ultra Wide Band: Ding Yi frequency-output characteristics figure ultra broadband).

In Fig. 1 to Fig. 2, on each the outside plate 11～14 that constitutes by sheet metal (electric conductivity) of vehicle 1, be electrically connected with the antenna terminal of UWB oscillator 21, it becomes the supply terminals a of outside plate 11～14.The outside plate 11～14 of each from the supply that supply terminals a receives microwave, is brought into play function as the antenna from its surperficial radiated microwaves, the electroconductive member of outside plate 11～14 formation present embodiments of each.

In the present embodiment, be illustrated as the example of antenna with outside plate 11～14, but also the front and back impact damper of vehicle 1, the case lid of saluting, hood, Qianmen, back door, slip car door, pendulum type door, other movable cover, movable roof iseikonia outside plate 11～14 the same electroconductive members as present embodiment can be used each.Wherein, Qianmen, back door, slip car door, pendulum type door all can be considered as being installed in the switching body of vehicle in switching mode freely.

This UWB oscillator 21, output can make the wide band frequency of outside plate 11～14 as the microwave of antenna radiation with the relative fully short frequency of size of the outside plate 11～14 of each of wavelength.As described in the explanation of Fig. 6, UWB (Ultra Wide Band: be not use carrier wave ultra broadband), set with the very narrow pulse of pulse width (impulse) row is used as the broadband frequency, under the condition of untuned, transmit the oscillator of signal, define by frequency-output characteristics figure by U.S. FCC (Federal Communications Committee).

In addition, the supply terminals a of the outside plate 11～14 of each is set in by emulation or emulation and actual machine is inferred or the point of correction affirmation.Equally, be used to receive from the microwave of outside plate 11～14 radiation of each, and detect spread state be each frequency radio wave propagation characteristic value be subjected to electricity point b, also be set in by emulation or emulation and actual machine and infer or revise the point of confirming.In the embodiment after embodiments of the present invention 2, set too.

Sending frequency is the UWB oscillator 21 of wide band microwave, the variation of the characteristic value of the radio wave propagations such as transport function of the resonance circuit that forms by outside plate 11～14 and surveyed area 11A～14A as antenna performance function, obtain the spread state of the microwave of this outside plate 11～14, described surveyed area 11A～14A is made of the electromagnetic wave radiation space that changes along with temperature, temperature, air pressure change around the outside plate 11～14.Specifically, UWB oscillator 21 can will have as resonant frequency by surveyed area 11A～14A and outside plate 11～14 definite multiple frequencies that are made of electromagnetic wave radiation space.

Also have, surveyed area 11A～14A is set in from the outside of outside plate 11～14 apart from the distance of the half-wave length of the frequency of the microwave that is equivalent to radiate.

In addition, reference oscillator 22, the oscillator of the microwave of forming by characteristic frequency (fo), and be the oscillator that sends the microwave of the frequency identical or approaching with UWB oscillator 21 usually, it is the frequency that the variation of the spread state of surveyed area 11A～14A changes that described characteristic frequency (fo) is used to detect according to electromagnetic wave radiation space.This reference oscillator 22 uses the more stable oscillator of oscillation frequency (fo).

Bandpass filter 24 is wave filters of the specific frequency behind the selection elimination noise.In addition, radio-frequency amplifier 25 is the amplifiers that amplify the output of bandpass filter 24.And frequency mixer 23 carries out mixing with frequency (f) with from the frequency (fo) that reference oscillator 22 obtains, and forms mixing frequency (mf+nfo; Wherein, m, n be-∞～+ integer of ∞), wherein, frequency (fo) is by making outside plate 11～14 as the antenna performance function radioactive wave appearance microwave fully short to the size of outside plate 11～14, and the variation of the characteristic value by radio wave propagation, detect the existence of detected object 31 in surveyed area 11A～14A at outside plate 11～14.In addition, be the F-V converter 26 of voltage with frequency inverted, by detecting the frequency figure of voltage detecting through bandpass filter 24.Its result, frequency mixer 23 and F-V converter 26, by the variation of frequency figure is carried out mixing with the frequency (fo) that obtains from reference oscillator 22, by the frequency figure of F-V converter 26 Detection and Extraction, the variation of the magnitude of voltage of the frequency figure of corresponding each frequency of acquisition or the Waveform Matching (pattern matching) of each frequency figure.

Has the outside plate 11～14 that makes vehicle 1 UWB oscillator 21 as the frequency of the microwave of antenna radiation, between as detected object 31 on the surveyed area 11A～14A in electromagnetic wave radiation space and outside plate 11～14, form the resonance circuit of microwave, and supply with resonance energy to a plurality of resonant frequencies of determining by the spread state in this electromagnetic wave radiation space respectively.That is, forms resonance state by a plurality of resonant frequencies of being supplied with by UWB oscillator 21, cause reflection or absorption by other multiple frequency, their characteristic value is corresponding to each frequency.If detected object 31 is present in surveyed area 11A～14A, then this detected object 31 becomes antenna, with corresponding as the outside plate 11～14 of antenna performance function, antenna combination each other takes place.

At this moment, because detected object 31 becomes antenna, the antenna combination takes place between the outside plate 11～14 as antenna performance function, a plurality of oscillation frequency from outside plate 11～14 outputs are exerted an influence, cause detected object 31 to cause reflection or absorption, each frequency change is to be equivalent to from the frequency of the amplitude increase of the wavelength components (frequency content) that detects the distance of object 31, the frequency that amplitude reduces.

For example, the characteristic value of determining by outside plate 11～14, when detected object 31 did not exist, F-V converter 26 formed the specific frequency figure of variation of the magnitude of voltage of corresponding each frequency.But, if detected object 31 exists, then, cause the characteristic value of radio wave propagation to change, different frequency figure when F-V converter 26 forms and do not exist with detected object 31 because electromagnetic wave radiation space is the state variation of surveyed area 11A～14A.

Like this, because the bandwidth of UWB oscillator 21, therefore, the microwave that radiates from outside plate 11～14 has a plurality of resonant frequencies.On outside plate 11～14, be formed with standing wave according to the spread state in electromagnetic wave radiation space, if but the characteristic value of radio wave propagation because the existence of detected object 31 changes, be formed on the standing wave variation of outside plate 11～14 before then.

Frequency mixer 23, frequency (f) that will obtain from UWB oscillator 21 and frequency (fo) mixing that obtains from reference oscillator 22, and frequency reducing frequency conversion obtain the frequency figures by F-V converter 26.In addition, identification circuit 27 makes through the frequency of bandpass filter 24 as the signal through F-V converter 26, and by with the difference of the characteristic value of the radio wave propagation of microwave, detecting electromagnetic wave radiation space is the state variation of surveyed area 11A～14A.The variation of the frequency figure of this detection can be by will being equivalent to distance, size etc. state in advance as the reference frequency figure detecting, and infer distance, size etc. according to this reference frequency figure, thus, detection distance, size etc.

Therefore, if people etc. are approaching, the antenna combination each other of antenna then takes place people and outside plate 11～14 are considered as, people waits the variation of the characteristic value of each frequency when not existing to become the characteristic value of the radio wave propagation of each different frequencies before, therefore, can be with its change-detection as the frequency figure.

That is, at this moment, the information of detected objects 31 such as people, thing, size is judged by comparing with their characteristic and at the identification circuit 27 inner reference frequency figures that shine upon.This method can be distinguished the approaching of the variation in automatic shutter when operation of door and detected objects such as people or thing 31.

In addition, identification circuit 27 is imported its output to electronic control circuit 2.The electronic control circuit 2 of this embodiment is made of the computing machine of the detection of obstacles of carrying out the door open and close system, judgement can be when closing the safety shutter door, perhaps whether barrier exists, if detect people or works, then stop the switching of door, in vehicle 1, produce alarm tone.

Also have, constitute UWB oscillator 21, reference oscillator 22, frequency mixer 23, bandpass filter 24, the F-V converter 26 of the proximity sensor 10 of present embodiment, be built between each the outside plate 11～14 and inner panel (not shown) of vehicle 1.And the output of F-V converter 26 is to identification circuit 27 and electronic control circuit 2 outputs.Electronic control circuit 2 is the computing machine of carrying out the obstacle detector of door open and close system in this embodiment.

Like this, the proximity sensor 10 of present embodiment is equipped with: the electroconductive member that is made of the outside plate 11～14 that is installed in car body with integral type or separable mode; Be set in the surveyed area 11A～14A in the outside of outside plate 11～14; The UWB oscillator 21 of the wide band frequency of microwave is supplied with in output to outside plate 11～14; The electricity point b that is subjected to the supply terminals a of the UWB oscillator 21 that is different from the electroconductive member that is made of outside plate 11～14 eliminates noises by bandpass filter 24, and the frequency mixer 23 that carries out mixing with the frequency of reference oscillator 22 by input frequency reducing frequency conversion; By identification circuit 27 through the variation of the frequency Figure recognition surveyed area 11A～14A of frequency mixer 23.

The operation of the proximity sensor 10 of the present embodiment of Gou Chenging is as described below like this.

At first, UWB oscillator 21 is supplied with wide band microwave to each outside plate 11～14 and surveyed area 11A～14A of the vehicle 1 that forms resonance circuit.The characteristic value of radio wave propagation is the value of being determined by the relation between surveyed area 11A～14A, outside plate 11～14, the detected object 31.Whether change from the existence of the characteristic value of the radio wave propagation of each frequency of this outside plate 11～14 radiation according to detected object 31.

Promptly, the resonance circuit that constitutes by the detected object 31 of outside plate 11～14 and surveyed area 11A～14A, the microwave resonance that utilization is supplied with from UWB oscillator 21, in surveyed area 11A～14A, do not exist under the situation of the detected object 31 that causes reflection or absorb, form the characteristic value of the radio wave propagation of specific multiple frequency.Yet, under near the detected object 31 close situations of outside plate 11～14,31 reflections of microwave detected object or absorption.Like this, by the resonance circuit that the detected object 31 of outside plate 11～14 and surveyed area 11A～14A constitutes, show the characteristic value of the radio wave propagation of microwaves different when not existing with detected object 31.For example, if detected object 31 is present in surveyed area 11A～14A, then the spread state of the frequency of supplying with from UWB oscillator 21 is different when not existing with detected object 31.This difference is, eliminates noise by bandpass filter 24, only extracts the frequency of predetermined band, the frequency of this output and the output frequency (fo) of reference oscillator 22 are together imported frequency mixer 23, by these frequency mixer 23 mixing, the frequency reducing frequency conversion, and become mixing frequency (f+fo).The mixing frequency (f+fo) that comes from frequency mixer 23 is input to F-V converter 26, at this, by the frequency test pattern based on characteristic value.

The detection of mixing frequency (f+fo) is as described below, that is: will be made through the frequency of bandpass filter 24 by identification circuit 27 and discern by the state variation of surveyed area 11A～14A through the difference of the frequency figure of F-V converter 26.The variation of the frequency figure of this detection, state that can be by will being equivalent to distance, size etc. is inferred distance, size etc. in advance as the reference frequency figure detecting according to this reference frequency figure, detects distance, size etc.In addition, the reference frequency figure can detect the translational speed and the distance of outside plate 11～14 according to its pace of change.

UWB oscillator 21 is to send the oscillator that frequency of utilization is wide band microwave, therefore, can select at an easy rate and can form whole device at an easy rate from the multiple frequency of outside plate 11～14 radiation.In addition, the antenna of present embodiment is the outside plate 11～14 of vehicle 1.This switching causes the state variation of the surveyed area 11A～14A that is made of the electromagnetic wave of the humidity in the outside of following outside plate 11～14, temperature, air pressure change radiation space.Even in this case, the UWB oscillator 21 that sends wide band microwave can radiate multiple frequency, therefore, can correctly detect the detected object 31 of surveyed area 11A～14A.Particularly, under the situation of door as antenna with vehicle 1, can be used as burglary-resisting system, the sensor of (keyless enter system) etc. uses to exempt from key system, and, by selecting the frequency band of UWB oscillator 21, can also set surveyed area 11A～14A in apart from the scope about 30cm by the outside plate 11～14 of the door of vehicle 1.Therefore, the set positions that electromagnetic wave can also be radiated the space from the outside plate 11～14 of door apart from the scope about 30cm in.

The proximity sensor of embodiment 1, between the detected object 31 of outside plate 11～14 and surveyed area 11A～14A, form the resonance circuit of microwave, therefore, influencing each other of electromagnetic electric field magnetic field becomes big, be difficult to the influence of electrostatic capacitance of the detected object of examined regional 11A～14A, so improve accuracy of detection.Particularly, the proximity sensor of present embodiment is compared existing electrostatic capacitance detection mode type, and the influence of atmosphere such as the humidity in examined zone, temperature, water vapor, pressure ground does not detect, so the device cheapness.In addition, therefore the multiple frequency of UWB oscillator 21 radiation, if the application simulation result sets supply terminals a, is subjected to electricity point b, then can collect the radioactive wave from the electroconductive member that is made of outside plate 11～14 reliably.Thereby, detect closely easily, and can carry out the cheap status detection of making.

(embodiment 2)

In above-mentioned embodiment 1, have a pair of supply terminals a, be subjected to electricity point b.But, to implement under the situation of the present invention, supply is subjected to the electricity point to be not limited to supply terminals a, this is a pair of to be subjected to electricity point b, can also a plurality of electric some b that are subjected to be set as present embodiment.

Fig. 3 is the functional-block diagram of the proximity sensor of embodiments of the present invention 2.

The proximity sensor 10 of present embodiment 2 on the loop structure of embodiment 1, is provided with two places and is subjected to electricity point b on the electroconductive member that is made of outside plate 11～14.Had respectively by electricity point b at these: frequency mixer 123, it eliminates noise via bandpass filter 124, is amplified by radio-frequency amplifier 125, and input frequency reducing frequency conversion is carried out mixing with the frequency of reference oscillator 122; Identification circuit 27, it discerns the variation of surveyed area 11A～14A by the frequency figure through frequency mixer 123.The basic loop structure that appends in embodiment 2, with the loop structure of embodiment 1, that is, reference oscillator 22, frequency mixer 23, bandpass filter 24, radio-frequency amplifier 25, F-V converter 26, identification circuit 27 are identical.

Embodiment among Fig. 3 is illustrated in a plurality of examples that are subjected to electricity point b (two) is set on the electroconductive member that is made of outside plate 11～14.Be subjected to electricity point b can further improve the detection resolution characteristic in that a plurality of (more than two) are set on the outside plate 11～14 like this, and guarantee the S/N ratio.In this embodiment, will be subjected to electricity point b to be made as two, not only can detect the difference of two characteristic values, and compare with will be subjected to electricity point b to be made as one the time and can also improve the detection resolution characteristic.If be made as more than two by electricity point b, can also corresponding raising detect resolution characteristic certainly.

As this embodiment, under the big situation of the size of outside plate 11～14, for example, as embodiment 1, by a pair of supply terminals a, be subjected to electricity point b, may cause the distance when the electromagnetic wave of supply terminals a radiation turns back to (being subjected to electricity point b) once more to increase, signal attenuation, therefore by a plurality of electricity point b that are subjected to are set, can further improve sensitivity, and can keep S/N than good.

(embodiment 3)

In embodiment 1, have a pair of supply terminals a, be subjected to electricity point b, but implementing under the situation of the present invention, can also common power supply point a and be subjected to the electric b of putting.In addition, the proximity sensor 10 of above-mentioned embodiment 1, whether the existence that is used to detect detected object 31 but can also detect moving of detected object 31.

Fig. 4 is the functional-block diagram of the proximity sensor of embodiments of the present invention 3.

This embodiment 3 can form the structure that has supply terminals a and be subjected to electricity to put b the structure of only single supply terminals a (b) by user tropism's coupling mechanism 28.

In Fig. 4, directional coupler 28 is that the output of UWB oscillator 21 is supplied with to outside plate 11～14, but the frequency that will be superimposed upon outside plate 11～14 is not sent to UWB oscillator 21, and is sent to the loop of bandpass filter 24.That is, directional coupler 28, be prevent from supply terminals a reflection or prevent since supply to furthermore as the supply terminals a that is subjected to electricity point b, in the output of the UWB oscillator 21 of outside plate 11～14 stacks, and the loop of its output frequency change.

The proximity sensor 10 of present embodiment 3 can constitute the embodiment with following member, that is: the UWB oscillator 21, and its fully short frequency of size of comparing outside plate 11～14 with wavelength makes outside plate 11～14 as antenna, supplies with wide band frequency; Frequency mixer 23, its supply terminals a and same supply terminals a at the UWB of outside plate 11～14 oscillator 21 eliminates noise by directional coupler 28, bandpass filter 24, input is sent the frequency reducing frequency conversion and is carried out mixing with the frequency of reference oscillator 22 outputs of frequency, and, detect Doppler frequency; Identification circuit 27, it discerns the variation of surveyed area 11A～14A by the variation of each frequency figure of process frequency mixer 23.

Therefore, the proximity sensor 10 of above-mentioned embodiment 3, if supply with microwave to outside plate 11～14 from UWB oscillator 21, then between the detected object 31 of surveyed area 11A～14A and the electroconductive member that constitutes by outside plate 11～14, form resonance circuit, and with each a plurality of frequency resonance based on the characteristic value of the radio wave propagation corresponding with each frequency of setting by this surveyed area 11A～14A and outside plate 11～14.At first, on identification circuit 27, record is based on the frequency figure that obtains from outside plate 11～14 of characteristic value of the radio wave propagation of this moment under the detected object 31 non-existent situations that cause reflection on surveyed area 11A～14A.If detected objects such as people 31 are near outside plate 11～14, then because different with the characteristic value of the corresponding radio wave propagation of each frequency of the surveyed area 11A～14A that constitutes by electromagnetic wave radiation space, cause the variation of resonant frequency of the resonance circuit that the detected object 31 by outside plate 11～14 and surveyed area 11A～14A forms.At this moment, on outside plate 11～14, generation is based on the standing wave of each frequency (wavelength) composition of the difference of the characteristic value of the radio wave propagation of detected objects such as people 31 influences.

Be superimposed upon a plurality of frequency of outside plate 11～14, extract by bandpass filter 24, in radio-frequency amplifier 25, amplify, with the frequency extracted and the output mixing of reference oscillator 22, utilize the frequency down mixing of reference oscillator 22, with the variation of this frequency output as F-V converter 26.The frequency figure that identification circuit 27 will detect as the output of F-V converter 26 compares with known in advance reference frequency figure, and by reference signal judging distance, size etc.In addition, identification circuit 27 can also detect the translational speed of detected object 31 according to the Doppler shift of each frequency of the variation of reference frequency figure.

(embodiment 4)

Above-mentioned embodiment 1 is to the proximity sensor 10 of embodiment 3, and whether the existence that is used to detect detected object 31 but can also detect moving of detected object 31.

Fig. 5 is the functional-block diagram of the proximity sensor of embodiments of the present invention 4.

The proximity sensor 10 of present embodiment 4 can constitute the embodiment with following member, that is: the UWB oscillator 21, and its fully short frequency of size of comparing outside plate 11～14 with wavelength makes outside plate 11～14 as antenna, supplies with wide band frequency; Frequency mixer 23, it is at the supply terminals b of the supply terminals a of the UWB oscillator 21 that is different from outside plate 11～14, eliminate noise by bandpass filter 24, carry out mixing by sending the frequency reducing frequency conversion with the reference oscillator 22 of frequency and the frequency of directional coupler 28 input UWB oscillators 21, and, detect Doppler frequency; Identification circuit 27, it discerns the variation of the spread state of surveyed area 11A～14A by the frequency of the predetermined band of process frequency mixer 23.

Therefore, the proximity sensor 10 of above-mentioned embodiment 4, if supply with microwave to outside plate 11～14 from UWB oscillator 21, then between the detected object 31 of surveyed area 11A～14A and the electroconductive member that constitutes by outside plate 11～14, form resonance circuit, and each a plurality of frequency resonance to set by this surveyed area 11A～14A and outside plate 11～14.Identification circuit 27, record based on frequency figure each frequency corresponding characteristics value under the detected object 31 non-existent situations that cause reflection on surveyed area 11A～14A, that obtain from outside plate 11～14.If detected object 31 is near outside plates 11～14, then the characteristic value of the radio wave propagation of each frequency in electromagnetic wave radiation space is different generates, the frequency graphic change of the resonance circuit that is formed by the detected object 31 of outside plate 11～14 and surveyed area 11A～14A.At this moment, on outside plate 11～14, produce standing wave difference, frequency (wavelength) composition of the characteristic value of the radio wave propagation that influences based on detected objects such as people 31.Be superimposed upon the frequency of the outside plate 11～14 of this moment, extract by bandpass filter 24, and, among both, extract the Doppler frequency composition the frequency extracted and the output frequency mixing of UWB oscillator 31, in addition, the frequency down mixing by reference oscillator 22.The variation of the frequency that obtains is judged by the frequency figure corresponding with each frequency of the output of F-V converter 26.Identification circuit 27 with the frequency figure that detects, compares with known in advance reference frequency figure, and by reference signal judging distance, size etc.In addition, identification circuit 27 can also detect the translational speed of detected object 31 according to Doppler frequency.

Identification circuit 27, can constitute by the mimic channel or the data circuit of the following stated, that is: by frequency figure based on the difference of the variation of the characteristic value of radio wave propagation, with above-mentioned electromagnetic wave radiation space is that the variation of surveyed area 11A～14A is with Figure recognition, by with the frequency figure, the reference frequency figure corresponding with known distance, size etc. compares, detect distance, size etc., in addition, the Doppler shift of each frequency by this frequency figure detects the translational speed of detected object 31.

At this, the proximity sensor 10 of present embodiment 1 to 4, have the fully short frequency of size that output compares outside plate 11～14 with wavelength and make the UWB oscillator 21 of outside plate 11～14 as the wide band frequency of the microwave of antenna radiation, between the detected object 31 of outside plate 11～14 and surveyed area 11A～14A, form resonance circuit, will based on the difference of the spread state of the frequency of supplying with from the supply terminals of UWB oscillator 21, surveyed area 11A～14A electroconductive member changes as the variation of frequency figure and detects.

Therefore, UWB oscillator 21 with frequency of the microwave that the outside plate 11～14 of vehicle 1 is supplied with as antenna, form the resonance circuit of microwave between as the detected object 31 of the surveyed area 11A～14A in electromagnetic wave radiation space and outside plate 11～14, from outside plate 11～14 radiated microwaves.Therefore, under the detected object 31 non-existent situations that cause reflection or absorb, produce the difference of the characteristic value of the radio wave propagation corresponding with characteristic frequency.In addition, if detected objects such as people 31, then radiate detected object 31 reflections in electromagnetic electric field magnetic field near outside plate 11～14 or absorb.Promptly, compare the people wait detected object 31 away from and when static, the characteristic value of the radio wave propagation in electromagnetic wave radiation space changes, and therefore collects as the difference of the Doppler shift of each frequency of frequency figure, and judge this frequency figure, can judge the velocity of approach and the distance of detected object 31 thus.

Also have, the proximity sensor 10 of present embodiment is used in vehicle 1, and therefore the structure member existence that can use as electroconductive member of the outside plate 11～14 of picture door much can also be used other structure members, therefore, be suitable as vehicle with and use.

(embodiment 5)

Above-mentioned embodiment 1 has used UWB oscillator 21 to the proximity sensor 10 of embodiment 4, but can be substituted by the output oscillator of the microwave that sends 300MHz～300GHz.At this moment, comprise the resonance circuit of microwave of the detected object 31 of surveyed area 11A～14A and surveyed area 11A～14A, become microwave oscillation portion 30.

Fig. 7 is the functional-block diagram of the proximity sensor of embodiments of the present invention 5.

In Fig. 7, sending frequency is the output oscillator 121 of the microwave of 300MHz～300GHz, from outside plate 11～14 radiated microwaves as antenna performance function, the electromagnetic wave radiation space on every side of detecting outside plate 11～14 is the variation of the spread state of surveyed area 11A～14A.The electromagnetic wave of being determined by surveyed area 11A～14A and outside plate 11～14 radiates the space, has specific resonant frequency based on the characteristic value of the radio wave propagation corresponding with a plurality of frequencies, therefore at UWB oscillator 121, use can be exported the excitation microwave oscillator of the oscillation frequency of oscillator 121 from external control.

Implementing the output oscillator 121 under the situation of the present invention, is the variation of surveyed area 11A～14A by electromagnetic wave radiation space, reflection-absorption that can corresponding oscillation frequency (f).The output of this output oscillator 121, the supply terminals a in outside plate 11～14 is electrically connected via frequency mixer 23.Also have, surveyed area 11A～14A is set in for the outside of outside plate 11～14 apart from the one-half wavelength distance of the frequency of the microwave of radiation.

Bandpass filter 24 is wave filters of only selecting a mixing frequency (f+fo), and in addition, VSWR measuring appliance 29 detects the VSWR through the frequency of bandpass filter 24.Its result, frequency mixer 23, will be from the output frequency (f) that obtains of oscillator 121 and the frequency that is superimposed upon outside plate 11～14, by the frequency that obtains from reference oscillator 22 (fo) mixing and frequency reducing frequency conversion, the frequency change of output oscillator 121 is extracted as the frequency of change difference via bandpass filter 24, detected the standing wave of the frequency of this extraction by VSWR measuring appliance 29.

At this moment, from the frequency that output oscillator 121 pairs of outside plates 11～14 are supplied with, be set to from outside plate 11～14 frequency that effectively ratio of all standing waves diminishes during radiation.For record for the purpose of careful is usually for improving from the emission efficiency of the microwave of outside plate 11～14 radiation, and will be set at minimum by the VSWR by frequency mixer 23 under detected object 31 non-existent situations.But, implementing under the situation of the present invention, it is not precondition that described VSWR is made as minimum.

Yet electromagnetic wave radiation space is the state variation of surveyed area 11A～14A, shows as departing from of frequency matching between outside plate 11～14 and surveyed area 11A～14A.The detection of this coupling by when detected object 31 does not exist, monitors VSWR measuring appliance 29 and makes the VSWR minimum.

Promptly, outside plate 11～14 and surveyed area 11A～14A, constitute with the fully short characteristic frequencies of the relative outside plate of wavelength 11～14 and make outside plate 11～14, comprise the detected object 31 of surveyed area 11A～14A and form the microwave oscillation portion 30 of the resonance circuit of microwave as antenna.

Like this, the frequency from the microwave of outside plate 11～14 radiation exists multiple.The frequency band of output oscillator 121 comprises part or all of frequency of the microwave of their radiation.Frequency mixer 23 will be measured its VSWR by VSWR measuring appliance 29 from the output frequency (f) that obtains of oscillator 121 and frequency (fo) mixing and the frequency reducing frequency conversion that obtains from reference oscillator 22.Will VSWR being made as minimum setting state by monitoring VSWR measuring appliance 29 is under the original state, if people etc. are approaching, the mutually combining of antenna of antenna takes place then people and outside plate 11～14 are considered as, and this will be detected as the variation of characteristic frequency.

In addition, identification circuit 27, by the signal that the VSWR measuring appliance 29 of detection by the VSWR of the frequency of bandpass filter 24 passed through, and the state variation of the surveyed area 11A～14A in identification electromagnetic wave radiation space.This signal that is detected changes, and is equivalent to the pre-reference information of the signal condition of distance, size etc. by mensuration, from this reference information deduction distance, size etc., and carries out the detection of distance, size etc.

That is, at this moment, as information such as the people of detected object 31, thing, sizes, by with their characteristic with in identification circuit 27 inner mapped data comparisons with reference to detecting.This method can be distinguished the approaching of the variation in automatic shutter when operation of door and people or thing.In addition, identification circuit 27 is input to electronic control circuit 2 with its output.

At this moment, constitute output oscillator 121, reference oscillator 22, frequency mixer 23, bandpass filter 24, the VSWR measuring appliance 29 of present embodiment, be built between each the outside plate 11～14 and inner panel (not shown) of vehicle 1.And, the output of VSWR measuring appliance 29, input is at identification circuit 27 and electronic control circuit 2.Electronic control circuit 2, becoming is the computing machine of carrying out the obstacle detector of door open and close system in this embodiment.

The proximity sensor 10 of present embodiment has: output oscillator 121, its output with the fully short frequency of the size of the relative outside plate 11～14 of wavelength with the detected object 31 of outside plate 11～14 and surveyed area 11A～14A microwave as resonance circuit; Reference oscillator 22, it sends the microwave that is used to obtain mixing; Frequency mixer 23, it will be by the microwave that obtains from output oscillator 121, and the output frequency by outside plate 11～14 and surveyed area 11A～14A obtain with the frequency mixing that obtains from reference oscillator 22, detects the frequency of regulation; Bandpass filter 24, it only selects specific frequency according to the frequency that detects at frequency mixer 23; Feedback system 28, it is determined from the feedback to output oscillator 121 of the specific output frequency of outside plate 11～14 radiation by the standing wave of the frequency of process bandpass filter 24; With identification circuit 27, its its by standing wave through the frequency of bandpass filter 24, the variation of identification surveyed area 11A～14A.

At this, the proximity sensor 10 of present embodiment, output oscillator 121, reference oscillator 22, frequency mixer 23, bandpass filter 24, VSWR measuring appliance 29 and feedback system 28, by standing wave, constitute the microwave oscillation portion 30 of the resonance that obtains the electrically conductive plate that constitutes by electromagnetic wave radiation space and surveyed area 11A～14A and outside plate 11～14 through the frequency of bandpass filter 24.Microwave oscillation portion 30, supplying with wavelength is the fully short frequency of size of the detected object 31 of surveyed area 11A～14A and the electrically conductive plate that outside plate 11～14 constitutes relatively by electromagnetic wave radiation space.

By this, the proximity sensor 10 of present embodiment, the fully short characteristic frequency of size with the electrically conductive plate that constitutes with the relative outside plate 11～14 of wavelength, make electrically conductive plate that outside plate 11～14 constitutes as antenna, comprise the detected object 31 of surveyed area 11A～14A and form the microwave oscillation portion 30 of the resonance circuit of microwave.

So and the proximity sensor 10 of the present embodiment that constitutes, following and work.

The proximity sensor 10 of present embodiment, the fully short characteristic frequency of size of the electrically conductive plate that constitutes with the relative outside plate of wavelength 11～14, make electrically conductive plate that outside plate 11～14 constitutes as antenna, comprise the detected object 31 of surveyed area 11A～14A and form the resonance circuit of microwave.If send microwave, then on outside plate 11～14, produce some standing waves based on the characteristic value of the radio wave propagation corresponding with each frequency.Even oscillation frequency being radiated as electromagnetic wave from outside plate 11～14, under detected object 31 non-existent situations, on electromagnetic wave radiation space, do not change yet, therefore, the frequency variation of the oscillation frequency of this moment is determined by execution conditions.Yet, if under the situation near near the of outside plate 11～14 or existence such as people, 31 reflections of electric field detected object or the absorption in electromagnetic wave radiation space, the change in location in the electromagnetic wave radiation space of surveyed area 11A～14A.

Like this, surveyed area 11A～14A, outside plate 11～14, relation between the detected objects such as people 27 is as follows, the output of output oscillator 121 is owing to the specific frequency of radiating from the outside plate 11～14 that forms the cavity oscillation circuit changes, like this, can form the loop structure of the resonance circuit of the microwave that is equivalent to the relative distance between detected object 31 and the outside plate 11～14, be subjected to the electric field of microwave, influencing each other of magnetic field is bigger than the influence of the electrostatic capacitance of detected object 31, can be considered as the resonance circuit of the electric field intensity (magnetic field) between the outside plate 11～14, be difficult to be subjected to the influence of electrostatic capacitance of the detected object 31 in electromagnetic wave radiation space.

The frequency of output oscillator 121 even radiated as microwave from outside plate 11～14, is causing that reflection or the detected object 31 that absorbs are not present under the situation in surveyed area 11A～14A the yet not change of frequency of output oscillator 121.Yet, if detected objects such as people 31 near outside plates 11～14 or have detected object 31, microwave detected object 31 reflections or absorb the change in location in electromagnetic wave radiation space.At this moment, if being equivalent to of the reflection wave that returns from outside plate 11～14 from the wavelength components (frequency) that detects the distance of object 31, for with the close frequency of frequency from the output oscillator 121 of outside plate 11～14 output, then become the state that multiple frequency content exists, but in fact, the frequency change as resonance effect is a frequency (f).The output frequency (fo) of this frequency change, reference oscillator 22 is imported frequency mixer 23, and by these frequency mixer 23 mixing, thus, the frequency of frequency reducing frequency conversion becomes mixing frequency (mf+nfo).To the mixing frequency (mf+nfo) from frequency mixer 23, the frequency of extracting the change difference by bandpass filter 24 is mixing frequency (f+fo), detects the standing wave of the mixing frequency (f+fo) of this extraction by VSWR measuring appliance 29.

Detection to the VSWR measuring appliance 29 of mixing frequency (f+fo), it is size according to the signal of process VSWR measuring appliance 29, by the state variation identification of surveyed area 11A～14A, 29 couples of VSWR by the frequency of identification circuit 27 process bandpass filter 24 of described VSWR measuring appliance carry out detection.This detected signal changes, and measures as reference information in advance by the signal condition that will be equivalent to distance, size etc., and infers distance, size etc. by this reference information, detects distance, size etc.

Particularly, output oscillator 121 is to send the oscillator that frequency of utilization is the microwave of 300MHz to 300GHz, therefore, can cheaply produce microwave, can cheaply form whole device.In addition, the antenna of present embodiment is the outside plate 11～14 of the door of vehicle 1.

Therefore as the outside plate 11～14 of door is the same can exist much as the structure member that electroconductive member uses also have, the proximity sensor 10 of present embodiment is used for vehicle,, can also use other structure members, thus be suitable as vehicle with and use.

(embodiment 6)

Above-mentioned embodiment 1 is to the proximity sensor 10 of embodiment 5, to wide as the frequency span of output frequency the UWB oscillator 21 or as output oscillator 121 active feedback be oscillation frequency, produce the example that oscillation frequency changes and be illustrated, but can also implement to be sent easily the oscillator of influence of output oscillator of the microwave of 300MHz～300GHz.

Fig. 8 is the proximity sensor electroconductive member functional-block diagram of embodiments of the present invention 6.

Output oscillator 221 is to send the oscillator that frequency is the microwave of 300MHz～300GHz, from outside plate 11～14 radiated microwaves as antenna performance function, frequency can be displaced to the existence whether degree of detected objects 31 such as can judging desire detects on the surveyed area 11A～14A of the outside that is set in outside plate 11～14 people, object.

Specifically, this output oscillator 221 in other words, has used the dielectric oscillator (DRO) or the LC oscillator of coordinating with external factor of being easy to that does not have PLL circuit etc. because the external factor oscillation frequency changes easily.The antenna terminal of this output oscillator 221 is electrically connected with the electricity point that is subjected to of outside plate 11～14.Therefore, the state variation that this output oscillator 221 can be by surveyed area 11A～14A, and obtain the oscillation amplitude change etc. that its wavelength change is promptly exported the skew of the oscillation frequency of oscillator 221, this frequency.

Secondly, to the state variation in electromagnetic wave radiation space, the skew of the oscillation frequency of output oscillator 221, the influence that the equifrequent variation of oscillation amplitude change of this frequency produces are described.

Outside plate 11～14 is accepted from exporting the microwave that oscillator 221 sends, to the outside direction radiated microwaves of outside plate 11～14.On the surveyed area 11A～14A in electromagnetic wave radiation space, exist under the situation of detected object 31, from 31 reflections of electromagnetic wave detected object or the absorption of outside plate 11～14 radiation, the electromagnetic influence of this reflection or absorption shows as the variation of the output frequency of output oscillator 221.That is, detect the zone of detected object 31 by outside plate 11～14 and bring into play functions, whether exist according to detected object 31 to have different numerous resonant frequencies as resonance circuit 51.Be considered as the constructional device that it is specialized if will export oscillator 221, promptly the microwave generation device 52, then have a plurality of resonant frequencies about 2～3.

At this, the oscillation frequency that integral type connects resonance circuit 51 and microwave generation device 52 is akin frequency, so the oscillation frequency of resonance circuit 51 converges with the oscillation frequency of output oscillator 221, and both are with common one specific resonant frequency vibration.

Promptly, outside plate 11～14 as the resonance circuit 51 of antenna radiated microwaves with by the abundant microwave generation device 52 that constitutes of the output oscillator 221 of short frequency of the size of the relative outside plate 11～14 of output wavelength, is formed with the quasi loop 50 that becomes a common specific resonant frequency.

From the output of output oscillator 221, and from the microwave of outside plate 11～14 radiation, detected object 31 reflections or absorb.The existence of detected object 31 in this quasi loop causes 31 reflections of electromagnetic wave detected object or absorption from outside plate 11～14 radiation, and its result shows as the variation of the output frequency that causes output oscillator 221.The detection of detected object 31, the skew of oscillation frequency that can be by detecting output oscillator 221, the variations such as oscillation amplitude change of frequency, and the existence that can obtain detected object 31 whether, translational speed, size etc.

As mentioned above, from outside plate 11～14 radiated microwaves the time,, then form outside plate 11～14 and the detected object 31 mutual quasi loops that are regarded as the cavity resonance loop 50 as antenna performance function if detected object 31 is close.In quasi loop 50, surveyed area 11A～14A, become from the output of output oscillator 221 and from the microwave of outside plate 11～14 radiation, detected object 31 reflections or absorb, and cause exporting the amplitude of skew, characteristic frequency of the oscillation frequency of oscillator 221 and the 2 dimensional region that reacts.Equally, electromagnetic wave radiation space can also become the three-dimensional three dimensions that covers the microwave of surveyed area 11A～14A of radiation.Therefore, the electromagnetic wave radiation space of the surveyed area 11A～14A of embodiments of the present invention is described, whichsoever all represents to detect the zone of detected object 31.

On the other hand, reference oscillator 22 is to utilize the output frequency in PLL loop etc. to be difficult for changing the loop of (frequency of output temperature), and be the oscillator that sends the stable microwave that the specific frequency (fo) by the influence of the state variation that is not subjected to electromagnetic wave radiation space constitutes, usually, with the output frequency frequency reducing frequency conversion of frequency mixer 23 with reference oscillator 22.

In addition, 32 pairs of signals through bandpass filter 24 of wave detector carry out detection, and the amplitude of the frequency of conduct regulation.The wave detector 32 of this bandpass filter 24, because the specific mixing frequency (f+fo) of a demodulation gets final product, therefore implementing under the situation of the present invention, can not consider the order of the signal Processing of bandpass filter 24 and wave detector 32, as long as frequency change is passed through reference oscillator (fo) mixing, extract specific frequency by bandpass filter 24, carry out detection, be converted to amplitude variations and get final product by the frequency of 32 pairs of these extractions of wave detector.

And then identification circuit 27 distinguishes that by the variation identification through the amplitude (voltage) of the skew of the frequency of wave detector 32 and characteristic frequency thereof 32 pairs of signals through the frequency of bandpass filter 24 of described wave detector carry out detection.The skew of the frequency that detects and the amplitude variations of characteristic frequency thereof are measured as reference voltage in advance, and are inferred distance, size, translational speed according to this frequency shift (FS), reference voltage by the distance that will be equivalent to detected object 31, the frequency displacement of size, the amplitude of characteristic frequency.Thereby, specifically, constitute by storeies such as F-V converter, FFT etc., and have the Storage Mapping figure of storage, compare and judge the variation in electromagnetic wave radiation space with the information of this Storage Mapping figure through the skew of the frequency of frequency mixer 23, the oscillation amplitude change of this frequency etc.But, when the frequency band with bandpass filter 24 dwindles, can be with when there be detected object 31 in surveyed area 11A～14A and when existence, detect having or not by two values (ON, OFF) through the detected object 31 of bandpass filter 24.

And, directional coupler 28, because the output of output oscillator 221 depends on that electromagnetic wave radiation space is the state variation of surveyed area 11A～14A, and change its output frequency, therefore the frequency content that only will change is input to frequency mixer 23, so that the output of reference oscillator 22 is not exerted an influence.

Promptly, at this moment, people, thing, their skew of frequency of size etc. and the amplitude information of frequency, by their information and skew and the amplitude information as the frequency of benchmark identification circuit 27 in are compared reference, and deduction is apart from the distance of detected object 31, the size of detected object 31, the translational speed of outside plate 11～14.This method can also be distinguished the approaching of the variation in automatic shutter when operation of door of vehicle 1 and people or thing.

The proximity sensor of the present embodiment of Gou Chenging like this is as move followingly.

The output of output oscillator 21, each the outside plate 11～14 that makes vehicle 1 is as antenna, and from outside plate 11～14 to electromagnetic wave radiation space radiated microwaves.At this moment, form outside plate 11～14 and the detected object 31 mutual quasi loops that are regarded as the cavity resonance loop 50 as antenna performance function.The output that this is regarded as the quasi loop 50 in cavity resonance loop shows the frequency (f) that obtains from the output of exporting oscillator 221 as a frequency.Frequency that obtains (f) and the frequency (fo) that obtains from reference oscillator 22, in frequency mixer 23 with the frequency mixing that obtains from reference oscillator 22 and by the frequency reducing frequency conversion, confirm through the skew of the frequency of frequency mixer 23, the oscillation amplitude change of this frequency by identification circuit 27, the existence that detects detected object 31 whether, translational speed, size etc.

Like this, the microwave that is equivalent to the relative distance between detected object 31 and the outside plate 11～14 is regarded as the quasi loop 50 in cavity resonance loop, influencing each other of the electric field magnetic field of microwave is bigger than the influence of the electrostatic capacitance of detected object 31, can be considered as the resonance circuit 51 of the electric field intensity (magnetic field) between the outside plate 11～14, not be vulnerable to the influence of electrostatic capacitance of the detected object 31 in electromagnetic wave radiation space.

Even the frequency of output oscillator 221 is radiated as microwave from outside plate 11～14, under the situation in the detected object 31 that causes reflection or absorption is present in electromagnetic wave radiation space, output oscillator 221 is not occurrence frequency change also.

Yet, if detected object 31 near near the outside plates 11～14, microwave detected object 31 reflections or absorb cause the state variation in electromagnetic wave radiation space.At this moment, the reflection wave that is equivalent to turn back to outside plate 11～14 from the frequency content (wavelength components) that detects the distance of object 31 is and the approximate frequency of frequency of the output oscillator of exporting from outside plate 11～14 221, in form, becomes the state that two kinds of frequencies exist.But, in fact, interosculate, be changed to a frequency (f) as resonance effect.The output frequency (fo) of this frequency change, reference oscillator 22 is imported frequency mixer 23, the frequency by these frequency mixer 23 mixing become the mixing frequency (| f+fo|) and the mixing frequency (| f-fo|).Come from frequency mixer 23 the mixing frequency (| f+fo|) and the mixing frequency (| f-fo|) mention the frequency that changes difference by bandpass filter 24, be the mixing frequency (| f+fo|) or the mixing frequency (| f-fo|), by wave detector (S curve characteristic device) 32 detect the mixing frequencies (| f+fo|) or the mixing frequency (| f-fo|), detect the mixing frequency (| f+fo|) or the mixing frequency (| amplitude f-fo|).By identification circuit 27 confirm by frequency mixer 23 the mixing frequency (| f+fo|) or the mixing frequency (| skew f-fo|), the oscillation amplitude change of this frequency, thus, the existence that detects detected object 31 whether, translational speed, size etc.

The output oscillator 221 of Shi Yonging is to send the dielectric oscillator that frequency of utilization is the microwave of 300MHz to 300GHz in the present embodiment, therefore can cheaply produce microwave, can cheaply form whole device.

Therefore, if make up, then, can open door by the close vehicle 1 of the driver of vehicle 1 with known Intelligent key.At this moment, electronic control circuit 2, for example, whether the opposition side that can detect the door of driver's side keeps the people, therefore, can give the alarm to the driver.In addition, electronic control circuit 2 can also make the door of driver's side not open, to giving the alarm unusually as required.Certainly, electronic control circuit 2 also can only be opened the door of driver's side, accelerates the driver and drives and take advantage of, and whole door is made as blocking.That is, can this be informed the driver by near the third party the difference vehicle 1 and the possessor of Intelligent key.In addition, electronic control circuit 2 is by distinguishing with Intelligent key, can also be made as the people near the time exempt from key and open door, the locking when people leaves.

(embodiment 7)

Above-mentioned embodiment 1 is to the proximity sensor 10 of embodiment 6, give oscillation frequency to the wide UWB oscillator 21 of the frequency span that uses output frequency, active feedback, the example that produces the output oscillator 121 that oscillation frequency changes is illustrated, but also can implement the present invention as oscillator with bring into play the outside plate 11～14 of function, the surveyed area 11A～14A of periphery that is set in this outside plate 11～14 and the space whether detected object 31 that desire detects exists as antenna.

Fig. 9 is the block scheme of the proximity sensor of embodiments of the present invention 7.

Each sheet metal etc. at vehicle 1 has on the outside plate 11～14 of electric conductivity, is subjected to electricity point b to be connected in series with bandpass filter 24, radio-frequency amplifier 25 and directional coupler 28 from it, and is connected on the supply terminals a.

Begin frequency from the electricity point b that is subjected to of outside plate 11～14 through the specific frequency band of the microwave of bandpass filter 24, amplify at radio-frequency amplifier 25, be fed into supply terminals a, the specific frequency that received by electricity point b at outside plate 11～14 is amplified at radio-frequency amplifier 25, and feed back to supply terminals a, become oscillatory regime.

In a word, be subjected to electricity point b, owing to, have white noise (white noise) from the noise of external environment condition etc. or the thermal noise of radio-frequency amplifier 25.Thereby, if make this noise as the gain of benchmark greater than 1, and the phase place of signal is to feed back under the conditions of 360 degree, then becomes oscillatory regime.

At this, directional coupler 28 can be exported to supply terminals a through radio-frequency amplifier 25 from bandpass filter 24, detects the frequency that received by electricity point b at outside plate 11～14.Frequency mixer 23, frequency (f) under the feedback states that is used for direction of passage coupling mechanism 28 is generated and frequency (fo) mixing that obtains from reference oscillator 22 specifically, obtain mixing frequency (mf+nfo) by mixing.In addition, S measuring appliance 33 (signal measuring apparatus) detects the output (amplitude of characteristic frequency, the passing of frequency) of the mixing frequency (f+fo) of frequency (f) mixing under the feedback states that generates with direction of passage coupling mechanism 28.Its result, the variation of the feedback states frequency (f) down that direction of passage coupling mechanism 28 is generated is by oscillator (fo) mixing, the variation of the frequency by 33 these extractions of detection of S measuring appliance or the variation of ripple.

At this, the proximity sensor 10 of present embodiment, on outside plate 11～14, set supply terminals a and be subjected to electricity point b, the frequency of amplification from obtained by electricity point b, give supply terminals a with frequency feedback, thus, formation is with the fully short frequency of the size of the relative outside plate 11～14 of wavelength, make outside plate 11～14 send the oscillation circuit 60 of microwave, by being that surveyed area 11A～14A constitutes resonator as the electromagnetic wave radiation space around the outside plate 11～14 of antenna performance function and their outside plate 11～14 as antenna.

Implement the oscillator 22 under the situation of the present invention, be used to detect the variation of frequency (f) of outside plate 11～14 being sent the oscillation circuit 60 of microwave as antenna, will be from frequency (f) the frequency reducing frequency conversion of the oscillation frequency of outside plate 11～14 radiation.

In addition, S measuring appliance (signal measuring apparatus) 33, the variation of the oscillation frequency of the mixing frequency (f+fo) of frequency (f) mixing under the feedback states that detection and direction of passage coupling mechanism 28 generate.Its result, the variation of the frequency (f) under the feedback states that direction of passage coupling mechanism 28 generates is by oscillator (fo) mixing, and detects the frequency of this extraction by S measuring appliance 33.

At this moment, by outside plate 11～14 and the radiation of the electromagnetic wave around them space as antenna performance function is the frequency of the resonator of surveyed area 11A～14A formation, when detected object 31 does not exist, make it to become more than the threshold value of regulation by monitoring S measuring appliance 33.But, if detected object 31 exists, be the state variation of surveyed area 11A～14A then by electromagnetic wave radiation space, the oscillation frequency between outside plate 11～14 and the surveyed area 11A～14A changes, and therefore, the output of S measuring appliance 33 is lower than the threshold value of regulation.

Like this, frequency mixer 23 with frequency (f) under the feedback states of direction of passage coupling mechanism 28 generations and frequency (fo) mixing and the frequency reducing frequency conversion that obtains from reference oscillator 22, and passes through the output that S measuring appliance 33 is measured characteristic frequency.Monitor the variation of the output (skew of frequency, the amplitude of characteristic frequency) of the characteristic frequency that S measuring appliance 33 obtains, by detected object 31 near or when existing, generation is considered as the antenna combination each other of antenna with detected object 31 and outside plate 11～14, detects as frequency change.

And then identification circuit 27 will be the state variation identification of surveyed area 11A～14A as electromagnetic wave radiation space through the output of the amplitude of skew, characteristic frequency or each frequency of the frequency of bandpass filter 24 etc. by the signal through S measuring appliance 33.The variation of the frequency that this is detected is measured as the reference frequency graphical information by the state that will be equivalent to distance, size etc. in advance, infers distance, size etc. according to this reference frequency figure, detects distance, size etc. thus.In addition, this detects content, can also with according to the reference frequency figure over time as translational speed.At this moment, the reference frequency figure of people, thing, size etc. is judged by the size of their characteristic and mapped frequency, amplitude in identification circuit 27, their data of reference frequency figure of pace of change etc. are compared.This determination methods can distinguish door automatic shutter when operation variation and static or mobile in the people or thing near state.

At this moment, constitute reference oscillator 22, frequency mixer 23, bandpass filter 24, radio-frequency amplifier 25, directional coupler 28, the S measuring appliance 33 of present embodiment, be built between each the outside plate 11～14 and inner panel (not shown) of vehicle 1.And, the output of S measuring appliance 33, input is at identification circuit 27 and electronic control circuit 2.Electronic control circuit 2 is the computing machine of carrying out the obstacle detector of door open and close system in this embodiment.

Like this, the proximity sensor 10 of present embodiment has: oscillation circuit 60, its radio-frequency amplifier 25 that feeds back to supply terminals a after by bandpass filter 24 and amplification frequency constitutes, described bandpass filter 24 will be by with supply terminals a and be subjected to electricity point b to be set in outside plate 11～14, and amplify from the frequency that obtained by electricity point b, to feed back to supply terminals a after this frequency amplification, with the fully short frequency of the size of the relative outside plate 11～14 of wavelength, make outside plate 11～14 as antenna send microwave from being subjected to frequency that electricity point b obtains as specific frequency band; Directional coupler 28, it is connected from being subjected to electricity point b to the path the supply terminals a, detects the oscillatory regime of oscillation circuit 60; Frequency mixer 23, it detects the feedback states that direction of passage coupling mechanism 28 generates by input frequency reducing frequency conversion with the frequency mixing; Identification circuit 27 is by the variation through the frequency identification surveyed area 11A～14A of frequency mixer 23.

Therefore, with the oscillation circuit 60 of outside plate 11～14, put b via the frequency of frequency mixer 23 from the electricity that is subjected to of outside plate 11～14, after radio-frequency amplifier 25 amplifies the frequency of these frequency bands as specific frequency band as antenna, supply to the supply terminals a of outside plate 11～14, the vibration microwave.From outside plate 11～14 electromagnetic wave is emitted to surveyed area 11A～14A,, will promptly form resonance state from the specific frequency state of outside plate 11～14 radiation by a plurality of frequencies according to the relation of this surveyed area 11A～14A and outside plate 11～14.Even from the oscillation frequency of outside plate 11～14 radiation oscillation circuits 10, causing that reflection or the detected object 31 that absorbs are not present under the situation of surveyed area 11A～14A, and the frequency variation of oscillation frequency does not take place yet.

But, if detected objects such as people 31 near surveyed area 11A～14A as electromagnetic wave radiation space, then and outside plate 11～14 between form the resonator of microwave, from the resonant frequency state variation of outside plate 11～14 radiation.That is, if detected objects such as people 31 near near the outside plates 11～14, then electric field detected object 31 reflections of surveyed area 11A～14A or absorb the change in location in electromagnetic wave radiation space.The variation direction of passage coupling mechanism 28 of the position in electromagnetic wave radiation space together is input to frequency mixer 23 with this and frequency reducing frequency conversion with frequency as the change-detection of frequency, by frequency through frequency mixer 23, and the variation of identification surveyed area 11A～14A.

The oscillation frequency of this oscillation circuit 60, the feedback states with direction of passage coupling mechanism 28 generates has frequency mixer 23 mixing of frequency reducing frequency conversion with frequency with input, by the frequency through frequency mixer 23, is judged the variation of surveyed area 11A～14A by identification circuit 27.That is, direction of passage coupling mechanism 28 extracts the frequency of oscillation circuit 60, judges the figure that has (signal measuring apparatus output) of this oscillation frequency.The frequency figure that this is detected, in advance with the variation of the frequency of the distance of corresponding surveyed area 11A～14A, size etc. as the reference frequency graphics memory, relatively this known reference frequency figure and the frequency of detection according to this reference frequency figure, detect the distance, size of detected object 31 etc.

When on the position of surveyed area 11A～14A, not having detected object 31, if be set at from more than the threshold value of the oscillation frequency specific of outside plate 11～14 radiation, then can when the threshold value that is lower than from the oscillation frequency specific of outside plate 11～14 radiation, detect the variation of detected object 31 as the position of surveyed area 11A～14A.

And then, identification circuit 27, being generally used for electromagnetic wave is radiated the space is that the variation of surveyed area 11A～14A is as the variation of oscillation frequency and discern, by comparing with corresponding reference frequency figures such as known distance, sizes, and detect distance, size etc., and, can constitute by mimic channel or digital circuit.

Particularly, on surveyed area 11A～14A as electromagnetic wave radiation space, when detected object 31 exists, regard as outside plate 11～14 and detected object 31 structure as the antenna cavity each other of antenna, the influence each other in electromagnetic thus electric field, magnetic field is big, be difficult to the influence of electrostatic capacitance of the detected object 31 of examined regional 11A～14A, therefore, improve accuracy of detection.

In addition, the antenna of present embodiment, it is the outside plate 11～14 of the door of vehicle 1, but switching along with door, the condition of outside plate 11～14 changes, and the state of surveyed area 11A～14A changes, even but in this case, because the frequency of oscillator 22 radiation can under any circumstance can both be set surveyed area 11A～14A.

Like this, the proximity sensor 10 of above-mentioned embodiment, has oscillation circuit 60, and with the variation of surveyed area 11A～14A change-detection as the frequency that obtains from oscillation circuit 60, described oscillation circuit 60 is by with supply terminals a and be subjected to electricity point b to be set in outside plate 11～14, and amplifies from the frequency that obtained by electricity point b, this frequency feedback given be subjected to electricity point b, with the fully short frequency of the size of the relative outside plate 11～14 of wavelength, make outside plate 11～14 send microwave as antenna.

Therefore, outside plate 11～14 is sent vibration as the oscillation circuit 60 of antenna, from outside plate 11～14 electromagnetic wave is emitted to surveyed area 11A～14A,, become from the resonance state of the specific frequency state of outside plate 11～14 radiation according to the relation of this surveyed area 11A～14A and outside plate 11～14.Even from the oscillation frequency of outside plate 11～14 radiation oscillation circuits 60, causing that reflection or the detected object 31 that absorbs are not present under the situation of surveyed area, and the frequency variation of oscillation frequency does not take place yet.But, if detected objects such as people 31 are near the surveyed area 11A～14A as electromagnetic wave radiation space, then with detected object 31 as antenna, and outside plate 11～14 between form the cavity oscillator of microwave, from the resonant frequency state variation of outside plate 11～14 radiation.That is, if detected objects such as people 31 near near the outside plates 11～14, the then electric field detected object of surveyed area 11A～14A reflection or absorb the change in location in electromagnetic wave radiation space.By detecting this, can detect the approaching of detected object 31.

At this, but outside plate 11～14 can be integral type or the electric conductor that is installed in mounting object separably.In addition, be set in the surveyed area 11A～14A in the outside of outside plate 11～14, the wavelength by outside plate 11～14 and microwave etc. are determined, but are set in 1m usually with interior distance arbitrarily.Also have, oscillation circuit 60 is so long as by with supply terminals a and be subjected to electricity point b to be set in outside plate 11～14, and amplifies from the frequency that obtained by electricity point b, feeds back to supply terminals a after this frequency is amplified, and sends microwave and gets final product.And then, the detection that the variation of above-mentioned surveyed area 11A～14A is carried out as the variation of the frequency that obtains from oscillation circuit 60, the variation of detected object 31 that is near the people etc. with outside plate 11～14 is as the change-detection of the frequency that obtains from oscillation circuit 60, can be with the variation of frequency as test pattern, also can by with relatively the judging of the threshold value of regulation.

Therefore, the oscillation frequency of microwave changes according to surveyed area 11A～14A and detected object thereof 31, and therefore electromagnetic electric field, magnetic field influence each other are big, is difficult to be subjected to the influence of electrostatic capacitance of the surveyed area 11A～14A in electromagnetic wave radiation space.

Particularly, the proximity sensor 10 of present embodiment, the oscillation circuit 60 of microwave can be regarded as and as the cavity between the detected object 31 of surveyed area 11A～14A, the influence each other of electromagnetic electric field, magnetic field is big, be difficult to be subjected to the influence of electrostatic capacitance of the detected object 31 in electromagnetic wave radiation space, therefore improve accuracy of detection.In addition, the proximity sensor 10 of present embodiment, because frequency of utilization is the use of the microwave of 300MHz to 300GHz, compare the detection mode type of existing electrostatic capacitance, the influence of atmosphere such as the humidity of examined regional 11A～14A, temperature, water vapor, pressure ground does not detect, so the device cheapness.And the proximity sensor 10 of present embodiment detects differently with the Doppler of the use of microwave, even the detected object 31 of surveyed area 11A～14A does not move, also can detect.Thereby the proximity sensor 10 of present embodiment is easy to carry out the detection of short range, and can carry out can the cheap status detection of making.

That is, the proximity sensor 10 of present embodiment, direction of passage coupling mechanism 28 extracts the oscillation frequency of microwave, judges its oscillation frequency figure.The figure of the oscillation frequency of this detection is as the reference frequency graphics memory of the distance of corresponding detected object, size etc., and compare with data that direction of passage coupling mechanism 28 detects, according to this reference frequency figure, the distance of detection detected object, size etc. also detect its speed as required.

At this moment, when detected object 31 does not exist on surveyed area 11A～14A, if will be made as specific threshold value from the oscillation frequency specific of outside plate 11～14 radiation simply, the then frequency variation of this threshold value relatively by detecting, the detection that can connect, close detected object detects the variation as the position of surveyed area.

And if the frequency of using is the microwave of 300MHz to 300GHz, then the influence of atmosphere such as the humidity of examined regional 11A～14A, temperature, water vapor, pressure ground does not detect, thereby device is cheap.Thereby the proximity sensor 10 of present embodiment is easy to carry out the detection of short range, and can carry out can the cheap status detection of making.

The proximity sensor of above-mentioned embodiment, by surveyed area 11A～14A of constituting by the electromagnetic wave radiation space of following humidity, temperature, air pressure change with together form the loop of microwave as the outside plate 11～14 of electroconductive member or the detected object 31 that exists.Detected object 31 by this surveyed area 11A～14A, the loop of the described microwave that forms with outside plate 11～14 as electroconductive member, if detected object 31 is present in surveyed area 11A～14A, then the spread state as the outside plate 11～14 of the electroconductive member of antenna performance function changes, therefore, can pass through the variation as the characteristic value of radio wave propagation this spread state, each wavelength components (frequency content), whether the existence of detection detected object 31.At this, electroconductive member is given by amplifying its vibrational feedback in the loop of the microwave of the detected object of detection surveyed area, can self-sustained oscillation.In addition, the loop of this microwave can be used as the loop by the microwave excitation electroconductive member excited oscillation that uses characteristic frequency.And the loop of this microwave owing to need obtain variation as the characteristic value of the radio wave propagation of the electroconductive member of antenna performance function, therefore, can form and has the loop structure of supply from the UWB oscillator of the frequency of the white noise of the energy supply of outside.

That is, embodiments of the present invention can constitute, and have: outside plate 11～14, and it is as the electroconductive member that is installed in mounting object with integral type or separable mode; Surveyed area 11A～14A, it is made of the electromagnetic wave radiation outside that is set in outside plate 11～14, that follow humidity, temperature, air pressure change space; Microwave circuit, it makes outside plate 11～14 as antenna performance function, the microwave that the radioactive wave appearance is fully short to the size of outside plate 11～14, the existence that will be present in the detected object 31 in the space in surveyed area 11A～14A with outside plate 11～14 detects as the characteristic value of radio wave propagation, and, can be with the variation of the characteristic value of the radio wave propagation in the loop of described microwave as the variation of described surveyed area and detect.

Therefore, between the detected object 31 and outside plate 11～14 of the surveyed area 11A～14A that radiates the space as electromagnetic wave, form the loop of the big microwave of the influence each other in electromagnetic electric field, magnetic field, propagate should surveyed area 11A～14A and the frequency of this detected object 31.Be not stored at detected object 31 under the situation in the outside of outside plate 11～14, determine the characteristic value of radio wave propagation such as propagator according to antenna characteristics in the lump.Particularly, because frequency of utilization forms the loop of microwave, electromagnetic electric field, magnetic field influence each other is big, be difficult to be subjected to the influence of electrostatic capacitance of the detected object 31 of surveyed area 11A～14A, therefore, compare the detection mode type of existing electrostatic capacitance, the influence of atmosphere such as the humidity of examined regional 11A～14A, temperature, water vapor, pressure ground does not detect, thereby device is cheap, improves accuracy of detection.In addition, different with the detection of Doppler frequency, even the detected object of not mobile surveyed area 11A～14A also can detect.In addition, on outside plate 11～14, have a plurality of resonant frequencies that can radiate, and detect the variation of its spread state, therefore, particularly, do not need carefully to investigate the characteristic of outside plate 11～14, just can implement as antenna performance function.

Thereby, embodiments of the present invention, can be used as the proximity sensor of advantage with the following stated, that is: do not exist along with the rain around the detected object or environmental change such as variation of temperature or when long deterioration cause maloperation, can miniaturization, cheapness and high precision, for example, even also can detect in that detected object is static, and, can the high speed detection speed, can also use on the object that vehicle etc. is made of metal.

The present invention not influence ground of the atmosphere such as humidity, temperature, water vapor, pressure of examined regional 11A～14A detects the detection of the short range of detected object 31, therefore, not only can be used as an open and close system obstacle detector, burglary-resisting system, exempt from the sensor of key system etc., and, compare existing electrostatic capacitance detection mode type, under the situation that meteorological conditions such as natural airborne humidity variation change, not influenced by it, therefore, the sensor that can be used as various detection short ranges uses.

Also have, the proximity sensor 10 of this embodiments of the present invention can also use the shower room toilet that moves, exists beyond vehicle, human body etc., and its purposes is not limited to vehicle.For example, can also as the sensor of the shower room toilet of the moving of human body, existence universalization.At this moment, for example, outside plate 11～14 is got final product as antenna performance function.Other structure is different from the embodiment described above.In addition, be installed on the mounting object and the outside plate 11～14 that forms is not limited to surface plate, can be processed as the shape of band shape, wire-like members with integral type or separable mode.

At this moment, the proximity sensor 10 of embodiments of the present invention, with integral type or the mode on the mounting object of being installed in separably electroconductive members such as outside plate 11～14 be provided on the mounting object get final product.

Also have, in unitized proximity sensor 10, can make the structure identical, and serve the same role, therefore, omit its detailed explanation with above-mentioned embodiment.

In addition, even be installed under the situation of vehicle 1, flick under the situation of detected object 31 by described impact damper under steam, its proximity sensor 10 with present embodiment is detected, the possibility that detected object 31 drops on the hood is big, therefore, hood is floated, and soft landing is in hood.Perhaps, on hood, make the air bag action.

And, be installed on the rear impact damper by proximity sensor 10 with present embodiment, can be used as the reversing sonar and use.

And then the proximity sensor 10 of present embodiment disposes by the seat at vehicle, and can detect the posture of whether taking one's seat, taking one's seat, and can also be used in the lifting of safety pillow, the control of seat gradient etc.

Claims (15)

1. proximity sensor is characterized in that having:

Electroconductive member, it is installed on mounting object with integral type or separable mode and forms;

Surveyed area, its electromagnetic wave radiation space with humidity, temperature, air pressure change by the outside that is set in described electroconductive member constitutes; With

Microwave circuit, it makes described electroconductive member bring into play function as antenna, the microwave that radiation is fully short with respect to the big small wavelength of described electroconductive member detects the existence of the detected object in the space in the described surveyed area as the variation of the characteristic value of radio wave propagation

With the variation of the detected described characteristic value of described microwave circuit, as the variation of described surveyed area and detect.

2. according to the described proximity sensor of claim 1, it is characterized in that,

On described microwave circuit, have the UWB oscillator of supply from the wide band frequency of the microwave of described electroconductive member radiation, between described electroconductive member and described surveyed area, form resonance circuit, according to the difference of the spread state of the frequency of supplying with from the supply terminals of described UWB oscillator, and detect the variation of described surveyed area.

3. proximity sensor according to claim 2 is characterized in that,

The detection of the variation of the characteristic value of described radio wave propagation, by using frequency mixer and identification circuit to carry out, at described frequency mixer, input frequency reducing frequency conversion frequency, to through behind the directional coupler and bandpass filter of supply terminals that is connected the UWB oscillator, the frequency of the described electroconductive member that is amplified by enlarger is carried out mixing, described identification circuit, frequency by through described frequency mixer detects the variation of described surveyed area.

4. proximity sensor according to claim 2 is characterized in that,

The detection of the variation of the characteristic value of described radio wave propagation, by using frequency mixer and identification circuit to carry out, at described frequency mixer, input frequency reducing frequency conversion frequency, be subjected to electric point to import the frequency of described electroconductive member from one or more the described of separate configurations, carry out mixing, described identification circuit, frequency by through described frequency mixer detects the variation of described surveyed area.

5. according to each described proximity sensor in the claim 2 to 4, it is characterized in that,

The detection of the variation of the characteristic value of described radio wave propagation, between described electroconductive member and described surveyed area, form resonance circuit, variation according to the spread state of the frequency of supplying with from the supply terminals of described UWB oscillator as the variation and the translational speed of described detected object, and detects.

6. proximity sensor according to claim 5 is characterized in that,

The variation of described detected object and the identification of translational speed, by using frequency mixer and identification circuit to carry out, at described frequency mixer, import the frequency of described electroconductive member, and input frequency reducing frequency conversion is carried out mixing with the frequency of frequency and described UWB oscillator, described identification circuit by the frequency through described frequency mixer, detects the variation and the translational speed of described detected object.

7. proximity sensor according to claim 1 is characterized in that,

Described microwave circuit has microwave oscillation portion, and it comprises described surveyed area and forms the resonance circuit of microwave.

8. proximity sensor according to claim 7 is characterized in that,

Described microwave oscillation portion has:

The output oscillator, it supplies with the frequency that generates from the microwave of described electroconductive member radiation;

Frequency mixer, the frequency of the microwave that it will obtain from described electroconductive member and carry out mixing from the frequency that reference oscillator obtains, and detect the frequency of regulation;

Bandpass filter, it is from only selecting specific frequency by the frequency of described frequency mixer mixing;

Feedback system, it gives described output oscillator by the frequency feedback through described bandpass filter.

9. according to claim 7 or 8 described proximity sensors, it is characterized in that,

Described microwave oscillation portion has identification circuit, and it discerns the variation of described surveyed area by the standing wave through the frequency of described bandpass filter.

10. proximity sensor according to claim 1 is characterized in that,

Described microwave circuit, has output oscillator to described electroconductive member output microwave, when in the surveyed area in the outside that is set in described electroconductive member, having detected object, between the detected object of described electroconductive member and described surveyed area, be formed with the quasi loop that is regarded as the cavity resonance loop, obtain the frequency of this quasi loop from described output oscillator, with the detected object of described surveyed area,, and detect as the variation of the oscillation frequency of described output oscillator.

11. proximity sensor according to claim 10 is characterized in that,

Outgoing side at described output oscillator has:

Frequency mixer, it will carry out mixing from the frequency of described output oscillator output with from the frequency that reference oscillator obtains;

Identification circuit, it is by the frequency of selection by described frequency mixer mixing, and the signal of the frequency of detection, and identification is set in the interior detected object of surveyed area in the outside of described electroconductive member.

12. according to claim 10 or 11 described proximity sensors, it is characterized in that,

Described output oscillator is dielectric oscillator or LC oscillator.

13. proximity sensor according to claim 1 is characterized in that,

By on the described electroconductive member of described microwave circuit, set supply terminals and be subjected to electric point, and amplification is from the described frequency that obtained by the electricity point, this frequency feedback is arrived described supply terminals, form to produce the oscillation circuit of microwave thus, the variation of described surveyed area is detected as the variation of the frequency that obtains from described oscillation circuit.

14. proximity sensor according to claim 13 is characterized in that, has:

Oscillation circuit, it is made of bandpass filter and radio-frequency amplifier, described bandpass filter will be subjected to frequency that the electricity point obtains as specific frequency band from described electroconductive member described, and described radio-frequency amplifier feeds back to described supply terminals after the frequency of this frequency band is amplified;

Directional coupler, it is connected in from the described electricity that is subjected to and puts path between the supply terminals, detects the oscillatory regime of described oscillation circuit;

Frequency mixer, its input frequency reducing frequency conversion frequency, mixing detects the feedback states that is generated by described directional coupler;

Identification circuit, it discerns the variation of described surveyed area by the frequency through described frequency mixer.

15. each the described proximity sensor according in the claim 1 to 14 is characterized in that,

Described electroconductive member is to install freely and the switching body that forms for vehicle open and close.

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