CN1979394A - Light-spot view-finding device and method - Google Patents

Abstract

The invention relates to a facula image picking-up device and method, emitting a highly coherent light from light source, when the highly coherent light irradiates surface, further generating scattered light, which passes through light limiting piece to form diffracted beams by aperture effect of the light limiting piece, where these diffracted beams interfere with one another to generate facula and limit scattered light to enter incident visual angle of a sensor by the blocking action of the light limiting piece so as to reduce deformation quantity of facula as moving, and finally the sensor picks up the facula into facula diagram, and continuous comparison of the facula diagram can identify moving direction and size of the facula. And it makes facula image clear and easy to identify, stable and sensitive.

Description

Light-spot view-finding device and method

Technical field

The present invention relates to a kind of apparatus and method of light-spot view-finding, particularly a kind of scattered light produces diffraction light by the light limiting piece of small-bore shape, and diffraction light interferes with each other again and become hot spot, and the apparatus and method of capture in addition.

Background technology

Laser is the very high a kind of light source of a coherence, therefore, when two-supremes coherence light beam bumps together, and its optical path difference is during less than coherent length (coherent length), can produce interference effect, and interference effect is divided into constructive interference and destruction interference, constructive interference is bright, and destruction interference is dark, so the interference effect figure of bright dark arrangement often.And interfere system relevant with wavelength, and when two light beams meet,, then can produce destruction interference if its phase differential is a half-wavelength, when being the integral multiple of wavelength, then can produce constructive interference as if its phase differential.Therefore, its sensing precision is a half-wavelength, and we know that light wavelength is quite short, are about 0.3 to 0.7 μ m as wavelength of visible light, and the precision of its variation is a half-wavelength, so quite sensitive.Therefore, use the occasion of interference effect, very extensive.

When more coarse surperficial of high coherence's light incident one, just can make high coherence's light produce scattering (scatter) because of coarse surface, the result of scattering makes incident light propagate toward any direction.Therefore, when two-supremes coherence's light bumps together and its optical path difference (OPD) during again less than its coherent length, just can produce stable interference.These high coherences' scattered light interferes with each other the image that can form many bright spots and dim spot, and we claim that this image is laser facula (Laser Speckle).

Hot spot is considered as noise by the people when discovery is not relevant with displacement, influenced image quality.But when having the people to find that displacement and hot spot have correlativity, hot spot just becomes a kind of measurement technology.Recently, mouse applications the has been arranged characteristics of hot spot, sensing technology when moving as mouse, as No. 20050024623 patent of U.S. Patent Publication No. (hereinafter referred to as 623 cases), a kind of optical displacement method and apparatus is disclosed, utilized and had coherence light source and launch coherence's light, incident one surface, therefore just there is a reflected light to leave the surface by surface reflection, there is a sensor to be positioned at catoptrical incoming position, accepting this reflected light, and the angle on incident light and surface, rough reflected light and the surperficial angle of equaling is to form so-called direct reflection (specular reflection).Because the reflected light image accepted of sensor contains many hot spots, thus via the light spot image of judging that this reflected light includes, with before moving with move after image compare, to judge that direction that hot spot moves is with big or small.

Another correlation technique is the patent application case of Patent Cooperation Treaty (PCT), and its publication number is WO2004075040 patent (hereinafter referred to as 040 case), discloses a kind of optical signal processing method and device of optical mouse of electric numerical data processing.It utilizes collects the signal that hot spot moves, with the laser light signal of reflection mouse and the relative displacement vector of the irradiated body surface that produces hot spot, its in order to device of realizing be built-in processing photosignal in the mouse body amplification and Shaping Module, take one's bearings and counting module and counter interface circuit, and comprise a LASER Light Source and receive by the photoelectric sensor of the laser facula signal of the body surface of laser radiation, this photoelectric sensor is input into the photosignal that receives in amplification, the Shaping Module.

Above-mentioned signal interpretation mode, all be interpretation by in the image that sensor captured, the bright dark variation of hot spot is with mobile direction and the distance size of converting.040 case simple in structure, but if the surface of incident is very smooth, then the size of the spot of Chan Shenging will become very little, like this, desire bright dark variation by the interpretation hot spot and will become and be not easy, therefore, its resolution will descend many, and sensitivity is not high.

And 623 cases are mainly by the reflected light of sensor reception near mirror, therefore, the signal that sensor received can be divided into direct current portion and exchange portion, what is called direct current portion is because catoptrical brightness is even, and the bright dark variation of hot spot is interchange portion, when the size of hot spot too hour, it changes i.e. interchange portion and just is difficult to distinguish, therefore, interpretation is more difficult.

Therefore, whether sensitive decision factor be the size of hot spot, and the effectively interpretation of too little hot spot is so how the size of may command hot spot is the whether key of sensitivity of sensing device.

Summary of the invention

Technical problem underlying to be solved by this invention is to provide a kind of light-spot view-finding device and method, so that diffraction effect takes place the light limiting piece of scattered light by the small-bore, and makes hot spot become big, so can monitor the variation of hot spot easily, to improve resolution.In addition, owing to stopping of light limiting piece limited the incident visual angle that scattered light enters sensor, therefore can effectively reduce the hot spot deflection when movable sensor reaches easy identification hot spot moving direction and size.

For reaching above-mentioned purpose, a kind of light-spot view-finding device provided by the present invention, can launch high coherence's light by light source, this high coherence's rayed one surface, and then produce scattered light, this scattered light passes through light limiting piece, make scattered light generation diffraction effect produce diffraction light because of the aperture of light limiting piece is little, and diffraction light interferes with each other and produce hot spot, and last sensor will capture this hot spot, and become hot spot figure.

In addition, utilize the light unit that contracts, the beam diameter of the high coherence's light that light source can be launched dwindles, or utilizes the optically focused mode to make laser beam get to the reduced of object surface, analysable dynamic range in the time of so can improving laser facula and move.

And a kind of light-spot view-finding method of the present invention, at first launch a branch of high coherence's light, this high coherence's light incident one surface produces a scattered light, this scattered light is by a light limiting piece generation diffraction, and produce a diffraction light, because of diffraction light interferes with each other, and produce a hot spot, writing down at last that hot spot forms is an image.

After described record hot spot forms and is the step of an image, also comprise via figure and contrast this image and monitor moving of hot spot, to differentiate moving with respect to the surface.

After the step of a branch of high coherence's light of described emission, also comprise the step of the beam diameter that dwindles high coherence's light.

Described high coherence's light incident one surface, and after producing the step of a scattered light, also comprise scattered light by time aperture, to limit the step that scattered light enters the incident visual angle of sensor.

High coherence's light incident one surface that is set forth in, and after producing the step of a scattered light, also be included in and put the step that a stop down enters the incident visual angle of sensor with the restriction scattered light between condenser and the sensor.

Therefore, desire moving of sensitive surface, or the mode of the motionless and mobile whole sensing architecture in surface, the height of its sensitivity depends on that the image of this hot spot must be clear and stable, and that the size of hot spot must reach greatly, contrast is enough strong, easy identification so, and move a certain apart from the time, the distortion of hot spot is enough little, so can do the action of identification.And the present invention has utilized diffraction and interference effect, make the size variable of hot spot big, and the image of hot spot can be clear, and move a certain apart from the time, the hot spot deflection is little, can be easy to identification, to reach requirement as above, so it is light-spot view-finding device of the present invention and method can be very stable, sensitive again.

About feature of the present invention and embodiment, existing conjunction with figs. is described in detail as follows.

Description of drawings

Figure 1A, Figure 1B and Fig. 1 C are system architecture diagram of the present invention.

Fig. 2 is the synoptic diagram that use light limiting piece of the present invention produces diffraction phenomena.

Fig. 3 is that hot spot of the present invention forms synoptic diagram.

Fig. 4 moves graph of a relation for hot spot of the present invention.

Fig. 5 A and Fig. 5 B are optical path difference synoptic diagram of the present invention.

Fig. 6 A, Fig. 6 B are the different embodiment synoptic diagram in the light unit that contracts of the present invention with Fig. 6 C.

Fig. 7 A is time aperture synoptic diagram that adds of the present invention.

Fig. 7 B is a light limiting piece of the present invention, and the restriction scattered light enters the incident visual angle synoptic diagram of sensor.

Fig. 8 is an application synoptic diagram of the present invention.

Fig. 9 A, Fig. 9 B and Fig. 9 C are light-spot view-finding method synoptic diagram of the present invention.

Wherein, Reference numeral:

100 surperficial 110 incident lights

120 scattered lights, 130 apertures

131 micro lens, 132 light barriers

140 imaging lens, 150 sensors

Light 170 circular holes of 160 tool coherences

180 luminous points, 190 screens

The 200 light sources 210 light unit that contracts

211 collector lenses, 212 first lens

213 second lens 214 the 3rd lens

215 aperture 300 laser mouses

310 housing δ half widths

λ wavelength d Circularhole diameter

Z is apart from OPD _AOptical path difference

OPD _BOptical path difference dl displacement

ψ _AAngle ψ _BAngle

ψ incident visual angle A point

B point E point

F point G point

H point A ' point

B ' some E ' point

F ' some A " point

B " some A _Eq" point

B _Eq" some O move before the aperture center

O ' moves the radius of aperture center, back R incident light irradiation scope

Z ' aperture and surperficial distance

Embodiment

See also Figure 1A, be depicted as system architecture diagram of the present invention.When light incident one surperficial 100 the time, its catoptrical characteristic is decided along with the roughness on surface 100, smooth more surface 100, and then surface 100 is more as mirror, can be almost completely with incident light 110 direct reflections, make catoptrical energy almost identical with incident light 110.If the roughness on surface 100 is big more, then surface 100 is more as vaporific, behind the surface 100 that incident light 110 incidents are vaporific, light almost the surface 100 on to the even scattering of all directions, this is after having very big being uneven to cause light incident because of surface 100, produce scattering effect, light is propagated to any direction.In addition, smooth more surface 100, its scattering effect is not obvious more, so the hot spot that produces is also not obvious.

Behind incident light 110 incidence surfaces 100, utilize imaging len 140 and sensor 150 to accept its scattered light 120.For making hot spot become bigger, we install a light limiting piece again additional before sensor 150, this light limiting piece is the combination of aperture 130 and imaging len 140, this aperture 130 is to be used for controlling its spot size, and before aperture 130 can place imaging len 140, as Figure 1A, or with aperture 130 place between imaging len 140 and the sensor 150 all can, as Figure 1B.Aperture 130 size and location at Figure 1B also can effectively limit the incident visual angle that the coloured light 120 that looses enters sensor 150 except the may command spot size.And sensor is dimension sensor in present embodiment, as two-dimensional image sensor such as CCD or CMOS, in order to the acquisition image.

In addition also can with aperture with imaging len make up in, become a micro lens 131, and around micro lens 131, be connected with the light limiting piece of light barrier 132, as Fig. 1 C, because the aperture of this micro lens 131 is little, so have effect as aperture 130, make scattered light generation diffraction effect and control spot size, and this micro lens 131 also has the effect as imaging len 140, scattered light is imaged on the sensor 150, and next how introduction makes the size of hot spot become big principle via light limiting piece.

See also Fig. 2, be depicted as the diffraction synoptic diagram of scattered light of the present invention,,, during through the circular hole 170 of a small-bore, have diffraction effect and produce as laser when the high coherence's of a tool light 160 through light limiting piece.Therefore, light can produce diffraction and form several concentrically ringed stripeds on screen 190, wherein, the centre is a maximum value, form a luminous point 180, the width of this luminous point 180 is 2 δ, and relevant apart from Z to screen 190 of the half width δ of this luminous point 180 and light wavelength λ, circular hole 170 diameter d and circular hole 170, and its relational expression is as follows:

$\mathrm{\δ}=1.22\frac{\mathrm{\λ}}{d}z$

And the scattered light 120 that acceptance is propagated from different directions, and each scattered light 120 is by behind the light limiting piece, the aperture 130 that the light limiting piece utilization of present embodiment has a small-bore can be realized assembly as one of the light limiting piece of present embodiment, all can cause same diffraction effect, as Fig. 3.Therefore, also can interfere effect between the different luminous points 180, the result of interference effect can produce bright spot and dim spot and be interspersed and form hot spot.The aperture of stop down 130 can make the size of this hot spot become many greatly, and so, the spot pattern that we utilize sensor 150 these bright spots of acquisition and dim spot to be interspersed just becomes many easily.

And in the system architecture of the present invention, after utilizing scattered light by light limiting piece with circular hole, produce diffraction effect, make the size of hot spot become many greatly, the minimum resolution unit of ratio sensor is bigger, so, sensor just can accurately demonstrate the shape of this hot spot and then pick out the mobile variation of hot spot.

Hot spot changes with moving of surface 100, therefore, and before move on surface 100 and after moving, its hot spot must change not quite, hot spot palpus before promptly moving and after moving is closely similar, so, and the direction and the size that can have enough relevances to come the identification hot spot to move.Yet hot spot was formed by 120 mutual interference of rough scattered light on surface 100, therefore just change intensity of hot spot along with the position, and it is changed to gradual variation, the variation of non-great-jump-forward, so, if apparent surface's 100 mobile spot image-taking devices are in certain distance the time, its hot spot can have very strong relevance, therefore, can be via the figure mode of comparing to judge moving of hot spot, to calculate the direction and size that light-spot view-finding device moves.

Yet the high coherence's of these light source 200 emissions light, general modal high coherence's light is laser light, so light source can be wall emission laser (Vertical Cavity Surface Emitting Laser, VESEL), or the limit that can launch high coherence's light penetrate type laser (Edge Emission Laser, EEL) or can launch narrow frequency light and have high coherence's light emitting diode.

See also Fig. 4, be depicted as hot spot of the present invention and move graph of a relation.When aperture 130 is not mobile, the scattered light 120 that A point and B are ordered images in the A ' point and the B ' point of sensor 150 via the O point of aperture 130, when aperture 130 move dl apart from the time (shown in dotted line), then A point and the B scattered light 120 of ordering images in the A of sensor 150 via O ' of aperture 130 " point and B " point.And when aperture 130 move dl apart from the time, 100 irradiated zones, surface are also to equidirectional mobile dl distance, be same as the relative position that the regional A of former irradiation orders and be called A on new irradiation area _EqPoint, the relative position that is same as former irradiation area B point is called B _EqPoint, then A _EqPoint and B _EqO ' some A that images in sensor 150 respectively of the scattered light of some aperture 130 after moving _Eq" point and B _Eq" point.Because sensor 150 and aperture 130 are to move simultaneously, therefore for sensor 150, A is to A ' and A _EqTo A " _EqBe identical geometric path, A and A _EqShould image in the same position of sensor 150, in other words, for sensor 150 A ' and A " _EqBe same point, in like manner, B ' and B " _EqIt is same point.From the spot pattern that sensor 150 is observed after moving, A point characteristic signal is by original A " _EqPoint moves to A " point, in like manner B point characteristic signal is by B " _EqPoint moves to B " therefore point can come interpretation point A with the figure control methods " _EqWith A " point and some B " _EqWith B " displacement relation of point, and then obtain direction and the size that sensor 150 moves.By A " _EqPoint moves to A " point, B " _Eq" the change of changing into the geometric optical imaging position of point that point moves to B.But in the Strength Changes of A " point or B " the some laser facula that measures is that to change caused optical path difference (OPD, optical pathdifference) big or small relevant with the reflected light path.Please consult Fig. 5 A and Fig. 5 B again, we relatively move the light path that back A order (this is that A is to A " light path) and move the light path that preceding A orders (this is A with being equivalent to _EqTo A " _EqLight path), and calculate the two optical path difference OPD _A, optical path difference OPD _AReach the incident visual angle ψ that the scattered light of being ordered by A enters sensor 150 with the displacement dl of aperture 130 _ARelevant (ψ _ABe defined as A point scattering light and the angle that passes through the aperture normal), its relational expression:

OPD _A≈dlsinφ _A

In like manner for the B point, its optical path difference OPD _BEnter the incident visual angle ψ of sensor 150 with the displacement dl of aperture 130 and the scattered light of ordering by B _BRelevant (ψ _BBe defined as B point scattering light and the angle that passes through the aperture normal), its relational expression:

OPD _B≈dlsinφ _B

If ψ _AWith ψ _BEquate, then optical path difference OPD _AWith optical path difference OPD _BBe equal, it is constant before this expression aperture 130 moves with the PHASE DISTRIBUTION that moves the back hot spot, be hot spot before moving with move after intensity distributions equate constant, in other words hot spot before mobile and the conoscope image after mobile constant, the moving direction of identification hot spot and size fully.But in fact, ψ _AWith ψ _BBe unequal, so optical path difference OPD _AWith optical path difference OPD _BAlso unequal, if both are when differing above certain value, the hot spot after moving just can be deformed to mobile before different fully, so just becoming can't identification.Yet optical path difference OPD _AWith optical path difference OPD _BDifference in how many scopes, hot spot side is unlikely, and be deformed to can't identification, this roughness with surface 100 is relevant.More many greatly from experimentally learning aluminium sheet, the tolerable maximum optical path difference value of copper coin than melamine board, the tolerable maximum optical path difference value of smooth printing paper.Though different tolerable maximum optical path difference values is arranged for Different Light, different surfaces, we are confirmable be to a kind of coherence light source 200 with a kind of surperficial 100, its maximum tolerable light path difference is a definite value.

So the variation of maximum tolerable light path difference is relevant with incident visual angle (the incident view angle) ψ that scattered light enters sensor 150, yet the radius r of this incident visual angle ψ and incident light irradiation scope and aperture 130 are relevant apart from Z ' with surface 100, and its relational expression is:

$\tan \mathrm{\φ}=\frac{r}{Z^{,}}$

When if incident visual angle ψ is very little, $\mathrm{\φ}\≈\frac{r}{{\text{Z}}^{\text{\′}}},$ And when if the light path difference of tolerable maximum is definite value, and aperture 130 and surface 100 apart from Z ' also for fixedly the time, desire to make incident visual angle ψ value to diminish, then represent the r value to diminish, this expression range of exposures must be dwindled, so when we moved a certain scope, it is little that light spot shape is changed, but remain on the identification scope.This is representing via in the framework of the present invention, as our apparent surface and mobile spot image-taking device during in a certain scope, the profile of hot spot is constant or its variation is very little, and because light-spot view-finding device is mobile, therefore, hot spot has imaged in the another location of sensor, so, via the image of record hot spot, and learn the direction and size that light-spot view-finding device moves by figure contrast.

Desiring to reach this condition of realization must diminish the diameter of incident light, when so we can launch light beam with light source 200, promptly light beam is dwindled by the light unit 210 of contracting, light beam irradiates is dwindled to the scope on surface 100, see also Fig. 6 A, Fig. 6 B and Fig. 6 C, we install a collector lens 211 additional in light source 200 front ends, the light that makes light source 200 is during by this collector lens 211, become the light beam of convergence shape, so, in the time of near surface 100 is positioned near the focus of this light beam, the range of exposures of light beam is diminished, as Fig. 6 A.In addition, also can install first collector lens 212 and second collector lens 213 additional, the focus of these first lens 212 and second lens 213 overlaps each other, and the focal length of first lens 212 and second lens 213 is respectively f1 and f2,

When f2＜f1, can make the reduced of incident beam Doubly, as Fig. 6 B.In addition, also can utilize first lens 212 and the 3rd lens 214 to form the light unit 210 that contracts, these the 3rd lens 214 are a divergent lens, so, and when first lens 212 overlap with the focus of the 3rd lens 214, can make the light beam that is incident in first lens 212, through dwindling behind first lens 212 and the 3rd lens 214, can reach the purpose of the light that contracts equally, and this kind erection mode can reduce the spacing of first lens 212 and the 3rd lens 214, help to dwindle the sensed object overall volume, as Fig. 6 C.

See also Fig. 7 A, except with light beam light source 200 deals with, also can handle in the part of accepting scattered light 120, promptly before scattered light 120 is incident in imaging len 140 and aperture 130, install time aperture 215 again additional, this time aperture 215 keeps off part scattered light 120 earlier, only allows certain a part of scattered light 120 to pass through, and the incident visual angle that scattered light is entered sensor 150 dwindles via this aperture 215.

See also Fig. 7 B, image on the sensor 150 through imaging len 140 2 of E, F on the reflecting surface 100, if aperture 130 places G point place, then 2 of E, F all can image in E ', F ' 2 points of sensor 150.If aperture 130 places H point place, then have only the F point of close optical axis can image in the F ' point of sensor 150 by aperture 130, the E point far away from optical axis can't pass through aperture 130, so can't image on the sensor 150.Therefore, suitably adjust the position of aperture 130 and big I reach simultaneously amplify spot size and effectively restriction scattered light 120 enter the incident visual angle of sensor 150.

Therefore, light-spot view-finding device of the present invention and method, can be applicable in the laser mouse 300, as Fig. 8, light source 200 and sensor 150 all are installed in the housing 310 of laser mouse 300, and light source 200 present via a collector lens 211 a branch of light be incident in the surface 100 on, therefore can produce scattered light 120, this scattered light 120 just makes the hot spot of scattered light 120 become big via imaging len 140 again through aperture 130, while and the incident visual angle of having limited scattered light 120 are received by sensor 150 at last.So, before housing 310 moves, the sensor 150 records first hot spot figure, after housing 310 apparent surfaces 100 move, the sensor 150 records second hot spot figure, via the relation of the image identification first hot spot figure and the first hot spot figure, to judge the moving direction and the displacement size of housing 310, to realize moving of computer mouse.

In above structure explanation, we can learn light-spot view-finding method of the present invention, see also Fig. 9 A, at first launch a branch of high coherence's light (step 500), and dwindle (step 510) behind the beam diameter of high coherence's light, this high coherence's light incident one surface, and produce a scattered light (step 520), and this scattered light passes through a light limiting piece, and make scattered light generation diffraction, and generation diffraction light (step 530), this diffraction light interferes with each other, and produces hot spot (step 540), and writing down that hot spot forms is an image (step 550) again, and contrast this image and the moving of identification hot spot via figure, and differentiate apparent surface's move (step 560).

See also Fig. 9 B, at first launch a branch of high coherence's light (step 500), this high coherence's light incident one surface, and produce a scattered light (step 511), this scattered light is by an aperture (step 521), and this scattered light is again by behind the light limiting piece, enter the incident angle of sensor in order to the restriction scattered light, and when scattered light passes through light limiting piece, scattered light generation diffraction, and produce a diffraction light (step 530), this diffraction light interferes with each other, and produces a hot spot (step 540), and writing down at last that hot spot forms is an image (step 550) again, and contrast this image and the moving of identification hot spot via figure, and differentiate apparent surface's move (step 560).

See also Fig. 9 C, at first launch a branch of high coherence's light (step 500), this high coherence's light incident one surface, and produce a scattered light (step 511), between imaging len and sensor, put an aperture and be combined into light limiting piece (step 522), when scattered light passes through this light limiting piece, scattered light enters the incident visual angle of sensor and can be limited by light limiting piece, and because of the diffraction by aperture effect of light limiting piece produces diffraction light (step 531), this diffraction light interferes with each other, and produce a hot spot (step 540), writing down at last that hot spot forms is an image (step 550) again, and contrast this image and the moving of identification hot spot via figure, and differentiate apparent surface's move (step 560).

So the present invention proposes a kind of view finding method and device of hot spot, install light limiting piece additional before being used in sensor, make hot spot become big and limited the incident visual angle that scattered light enters sensor, the deflection of hot spot when moving to reduce sensor so makes the spot pattern before and after moving be easy to identification.Therefore, light-spot view-finding method and apparatus of the present invention can be used on the various surfaces, when making scattered light pass through light limiting piece, light limiting piece produces diffraction effect, and the imaging point that makes scattered light becomes big, so can make the hot spot after the interference become big, and light-spot view-finding device of the present invention is in moving a certain scope the time, hot spot and then moves, and the variable quantity of hot spot is very little, therefore, judges that via the figure contrast the mobile of hot spot becomes quite easy.And the present invention also is applied to the view finding method and the device of this hot spot on the laser mouse, in order to the sensing mouse moving, and can be very accurate, sensitive.

Though the present invention with aforesaid most preferred embodiment openly as above; but be not in order to limit the present invention; any those of ordinary skill in the art; without departing from the spirit and scope of the present invention; when can doing a little change and modification, therefore scope of patent protection of the present invention must be looked this instructions appending claims person of defining and is as the criterion.

Claims (18)

1, a kind of light-spot view-finding device is characterized in that, comprises:

One light source is launched high coherence's light, and this high coherence's rayed one surface, and then produces an above scattered light;

One light limiting piece makes above-mentioned scattered light produce an above diffraction light, and this diffraction light interferes with each other and produces an above hot spot; And

One sensor is accepted above-mentioned hot spot, and is produced one first hot spot figure, when this light limiting piece and this sensor when should the surface moving, and produce one second hot spot figure, via this first hot spot figure of contrast and this second hot spot figure, with moving direction and the displacement of judging this light limiting piece and this sensor.

2, light-spot view-finding device as claimed in claim 1 is characterized in that, this light limiting piece is a micro lens, place this sensor before so that this hot spot images in this sensor, also make above-mentioned scattered light produce this diffraction light.

3, light-spot view-finding device as claimed in claim 1 is characterized in that, also comprises a light barrier, be connected in this micro lens around, in order to stop this scattered light of not taking.

4, light-spot view-finding device as claimed in claim 1, it is characterized in that, this light limiting piece comprises an aperture and an imaging len, before this imaging len places this aperture, so that above-mentioned scattered light is when imaging in this sensor by this imaging len, because of the aperture barrier effect has limited the incident visual angle that this scattered light enters sensor, the aperture effect because of aperture produces above-mentioned diffraction light again, and this diffraction light interferes with each other and produces above-mentioned hot spot, and images in this sensor.

5, light-spot view-finding device as claimed in claim 1, it is characterized in that, this light limiting piece comprises an aperture and an imaging len, before this aperture places this imaging len, so that above-mentioned scattered light produces above-mentioned diffraction light by this aperture, and this diffraction light interferes with each other and produces above-mentioned hot spot, and images in this sensor.

6, light-spot view-finding device as claimed in claim 5 is characterized in that, also comprises aperture one time, places this aperture towards this surface one side, and this time aperture and this aperture will limit the incident visual angle that this scattered light enters this sensor.

7, light-spot view-finding device as claimed in claim 1 is characterized in that, also comprises the light unit that contracts, and this light unit that contracts is a collector lens, places this light source front end, makes this high coherence solely become the light beam of a branch of contraction.

8, light-spot view-finding device as claimed in claim 1 is characterized in that, also comprises a collector lens, places this light source front end, and it is a branch of near parallel light beam that this high coherence is solely become.

9, light-spot view-finding device as claimed in claim 8 is characterized in that, also comprises the light unit that contracts, the reduced of high coherence's parallel beam that this light source is launched in this light unit that contracts.

10, light-spot view-finding device as claimed in claim 9, it is characterized in that, this light unit that contracts comprises one first collector lens and one second collector lens, and the focus of this first collector lens and this second collector lens overlaps each other, and the light beam of this high coherence's light is dwindled.

11, light-spot view-finding device as claimed in claim 9, it is characterized in that, this light unit that contracts comprises one first lens and one the 3rd lens, the focus of these first lens and the 3rd lens is overlapping, and the 3rd lens are a divergent lens, the light beam of this high coherence's light is dwindled, and can reduce the spacing of these first lens and the 3rd lens.

12, a kind of laser mouse is characterized in that, comprises:

One light source is launched high coherence's light, and this high coherence's rayed one surface, and then produces an above scattered light;

One light limiting piece makes above-mentioned scattered light produce an above diffraction light, and above-mentioned diffraction light interferes with each other and produces an above hot spot;

One sensor is accepted above-mentioned hot spot, and is produced one first hot spot figure, when this light limiting piece and this sensor when should the surface moving, and produce one second hot spot figure; And

One processing unit accepting this first hot spot figure and this second hot spot figure, and contrasts this first hot spot figure and this second hot spot figure, with moving direction and the displacement of judging this light limiting piece and this sensor.

13, light-spot view-finding device as claimed in claim 12, it is characterized in that, this light limiting piece comprises an aperture and an imaging len, before this imaging len places this aperture, so that above-mentioned scattered light is when this aperture, because of this aperture barrier effect has limited the incident visual angle that this scattered light enters this sensor, the aperture effect because of this aperture produces above-mentioned diffraction light again, and this diffraction light interferes with each other and produces above-mentioned hot spot, and images in this sensor.

14, a kind of light-spot view-finding method is characterized in that, comprises:

Launch a branch of high coherence's light;

This high coherence's light incident one surface, and produce a scattered light;

This scattered light passes through a light limiting piece, and makes this scattered light generation diffraction, and produces a diffraction light;

This diffraction light interferes with each other, and produces a hot spot; And

Write down this hot spot and become an image.

15, light-spot view-finding method as claimed in claim 14 is characterized in that, in record this hot spot and after becoming the step of an image, also comprises and contrasts this image and monitor moving of this hot spot via figure, to differentiate the step that moves with respect to the surface.

16, light-spot view-finding method as claimed in claim 14 is characterized in that, after the step of a branch of high coherence's light of emission, also comprises the beam diameter that dwindles this high coherence's light.

17, light-spot view-finding method as claimed in claim 14, it is characterized in that, in this high coherence's light incident one surface, and after producing the step of a scattered light, also comprise this scattered light by an aperture, make this time aperture and this light limiting piece to limit the incident angle that this scattered light enters this sensor.

18, light-spot view-finding method as claimed in claim 14, it is characterized in that, in this high coherence's light incident one surface, and after producing the step of a scattered light, also comprise this scattered light by a light limiting piece, make the hot spot of above-mentioned scattered light become big, and limit the incident angle that this scattered light enters this sensor.

Images