CN202443251U - Raster matrix recording system - Google Patents

Abstract

The utility model provides a raster matrix recording system. An electronic display panel is used as an optical element for producing two laser beams. The two laser beams interfere on a focusing plane of a lens and form a raster point, the shape of the raster point and the shape of beams are decided by diffraction wave-front of the electronic display panel. The raster matrix recording system is the only system which can combine beam interference and electronic display panel concept according to the known techniques. Other than the known techniques that only diffraction image of the electronic display panel is reduced, two different Fourier transforms can be achieved on the electronic display panel according to the raster matrix recording system. The laser beams are focused on recording materials firstly through the two Fourier transforms and secondly through the lens. In other words, the two laser beams are interfered with each other to produce the needed raster image. As the electronic display panel produces multi levels of wave-front light waves, a blocking plate with a single hole is needed to allow the entrance of light waves of predetermine levels.

Description

A kind of optical gate matrix formula register system

Technical field

The utility model relates to a kind of register system of matrix form grating lines, particularly about a kind of dot matrix (dot matrix) system, can on recording medium, make grating to produce the optical grating diffraction pattern by demand, can be applicable to fields such as wrappage application.

Background technology

Hologram sheet (hologram) is that the interference that the light beam with good coherence's wavefront (coherent wavefront) restrainted in record two is made.When hologram sheet by recording step in used wherein a branch of rayed, the diffraction light of its generation comprises messages such as phase place and amplitude with the wavefront of complete reproduction (reconstruct) another Shu Guang in recording step.That is to say the wherein a branch of wavefront of hypothesis from a three-dimensional body, this three-dimensional body image can or reproduce by diffraction pattern so." hologram sheet " speech not only may be defined as the element of reduction three-dimensional body image; Existing also being widely used in as any light beam that can make because of diffraction produces the element of multi-color decorative pattern (Patterns) can make this hologram sheet be applied to sign and other more purposes of wrapping paper, package cover, proof product authenticity through special design.

Making hologram sheet has several different methods, and the normal a kind of rainbow holography sheet (rainbow hologram) that has that uses only utilizes horizontal parallax (horizontal parallax) to produce 3-dimensional image, and with white light as reproducing this 3-dimensional image light source.Incrustation type hologram sheet then is to utilize two bundle parallel laser light beams, or is that two bundles have the identical angle of divergence and parallel laser produces interference by same laser beam light splitting.When a hologram pattern is made up of the grating region in many different angles and cycle, the record that wherein adjacent grating region must be continuous at grade.For these reasons, a kind of technology that is similar to the dot matrix system has been used to write down optical grating point (grating dot) pattern hologram sheet.

Fig. 1 is the synoptic diagram of a kind of known RP matrix grating hologram sheet system optics system; Wherein one incident laser light beam 101 is via prism 103 guiding spectroscopes 104; Be further divided into twice laser beam 105 and 106; After this two- beam 105 and 106 on record plane 108, overlap owing to only use 1 lens 102 will focus the light beam on the record plane 108, also can only one light beam in two- beam 105 or 106 be focused on the record plane 108 accurately; Must reach greatly so be positioned at the diameter of the focus point of record on the plane 108, could make the light beam of twice focusing all in the depth of focus of lens 102.And interference fringe spacing T=λ/sin θ that the light beam of two trace overlaps produces can adjust through the angle that changes prism 107, and the direction of interference fringe then can comprise prism 104 and prism 107 prism groups decide through rotation.This early stage design comprises following several problems:

(1) the required depth of focus causes on the record plane, forming excessive luminous point;

(2) because the optical path of twice laser beam is not isometric, so the employed laser beam of system needs bigger coherent length;

(3) light beam is penetrated the uneven circle that is shaped as on the record plane;

(4) interference fringe of adjacent gratings point is discontinuous.

Based on above shortcoming, the resolution of this early stage dot matrix grating register system only can reach 400dpi, and grating diffration efficient is not very high.

Fig. 2 is an another kind of RP matrix grating hologram sheet system.One laser beam 201 is divided into twice light beam 204 and 205, wherein light beam 205 directive prisms 206 then through catoptron 202 guiding spectroscopes 203.This system makes that through adding some prisms 207,208,209 and 210 path of left and right sides twice light beam is isometric, to reduce the high coherence's requirement to LASER Light Source.Lens 213 simultaneously with twice light beam 204 and 205 focus on the record plane 214 on, the focal spot diameter on this record plane 214 be δ=λ F/d wherein λ be Wavelength of Laser, F is the focal length of lens 213, d is the diameter of laser beam.Suppose the required spot diameter δ of this system=10 μ m and λ=0.5 μ m, can learn that F/d should be 20.Relative fringe spacing T=λ/2sin θ is because of the twice light beam is θ with the angle of optical axis respectively.Also there is following relational expression in the diameter that can be known focal length F and lens 213 by Fig. 2: tan θ=D/2F.If hope to obtain fringe spacing T=1 μ m, then angle of diffraction is required to be 14.5 °, and these focal length decision lens 213 must be f-2 lens.In this dot matrix system, prism 211 and 212 is wanted consistently to move up and down to change and is interfered angle θ, and and then change fringe spacing.Though this system slightly improves the part shortcoming of Fig. 1 system, on light spot form, luminous point homogeneity and striped continuity, still remain to be kept punching.

Optical system shown in Figure 3 has further solved the above-mentioned subproblem that still exists.Wherein laser beam 301 shines diaphragm 302 and gratings 303, and dwindles raster image to writing down on the plane 308 via lens 307.Diaphragm 302 can change empty shape on it, and the optical grating point that writes down thus on the plane 308 can be rectangle, hexagonal property or circle.Because laser beam 301 is by average diffusion, therefore shine light distribution meeting on grating 303 near evenly, the part 304 and 305 around particularly is also roughly the same.Grating 303 is fixed in a universal stage, and can rotate through computer control universal stage.The principle of work of this system is quite simple, and difficulty or ease are made but lens 307 can be subject to the basic optical principle.Suppose the focal length F=10mm of lens 307, and raster image is dwindled 10 times.For the optical grating point of ability recorded fringe spacing 1 μ m, and the laser beam of use wavelength X=0.5 μ m, then the spacing of grating 303 is 10 μ m.According to grating diffration angular dependence formula sin θ=λ/T, the angle of diffraction that can obtain the grating generation is 2.86 °.Dwindle effect for reaching 10 times, the about 100mm of this grating and lens distance.Therefore, first-order diffraction light and lens 307 centre distances are about 5mm, and this expression focal length and lens diameter ratio (f-number) are about 1.So in fact these lens are difficult to design, and also can't simplify through reducing the raster image minification.For example: reduce minification to 5, will shorten grating 303 and lens 307 distances to 50mm, thereby angle of diffraction will increase to 5.74 ° by 2.86 °, the result is the need one diameter lens consistent with focal length still.But when using LASER Light Source, and when blocking through 3030 grades of light waves of grating with the baffle plate 306 with spatial filter functionality, 308 intensity variation will be bigger than the variation on the grating 303 on the record plane for it, and its multiple is the twice of spatial frequency.This phenomenon can be done description below: the phase grating on the hypothetical record plane (phase grating) image complex amplitude is i (x)=1+sin (2 π x/T); After blocking 3030 grades of light waves of grating with baffle plate 306; Record plane 308 intensity variation be

because the coherence influences; System shown in Figure 3 can replace the f-1 lens with the f-2 lens and write down 1 μ m striped, but its adjacent striped is still discontinuous.

The method that also has two kinds of recording light gate figures is before grating and hologram sheet influence are placed a display panel, this image is dwindled and focuses on the base plate through optical system.Wherein a kind of system dwindles the image on the cathode ray tube (CRT) through microscope, and another kind then is that laser beam throws and images on the recording materials through display panels.

The utility model content

The utility model provides a kind of optical gate matrix formula register system; Use Electronic Display Panel for producing two bundle laser optical elements; Two bundle laser are interfered on the focussing plane of lens and are formed optical grating point, before its shape and beam shape will depend on the Electronic Display Panel diffracted wave.The utility model is unique system that can combine beam interference and Electronic Display Panel notion in the known technology.Being different from known technology only dwindles the diffraction image of Electronic Display Panel.The utility model is on Electronic Display Panel, to reach two kinds of different Fourier transforms (Fourier transform); Laser beam is through these two kinds of Fourier transforms; Restraint laser focusings through a slice lens on recording materials with two again; Just let this two bundles laser interfere each other,, therefore need a slice to have the baffle plate of single hole to allow the light wave of predetermined progression to pass through because Electronic Display Panel can produce multistage wavefront light wave to produce needed raster graphic.

A kind of optical gate matrix formula of the utility model register system can comprise with the raster graphic projection on recording materials:

An Electronic Display Panel;

A laser instrument, wherein this Electronic Display Panel of beam of laser beam direction;

A polarization wave filter is arranged between Electronic Display Panel and recording materials, and its permission is shone and sent specific polarization light in this Electronic Display Panel laser instrument and pass through;

A controller is connected in this Electronic Display Panel, and can drive this Electronic Display Panel and show many patterns picture, and produces at least twice and separate output beam;

A slice baffle plate can allow the specific exponent number of this output beam to pass through;

One lens can focus on this recording materials with this output beam, and this output beam forms raster graphic on these recording materials because of interfering with each other.

In some embodiments, this Electronic Display Panel is a liquid crystal panel, and laser beam is incident upon on the liquid crystal panel through spectroscope, reflects back again again and reaches recording materials through spectroscope, baffle plate and lens.Another kind of embodiment is that laser beam is directly sent by the liquid crystal panel rear and penetrates liquid crystal panel and go out.Display pattern through on the control liquid crystal panel can absorb the light beam of laser beam middle section, and produce two kinds of wavefront light beams, also just has two bundle different laser light beams to be penetrated by liquid crystal panel.In some embodiment, LCD can be modulated the amplitude before the laser wave, or the phase place of modulated laser wavefront.

After each optical grating point record finishes, can the moving recording material with respect to the position of laser beam, so just can produce an optical grating point matrix, and each optical grating point can have the raster graphic of uniqueness.Another technical characterictic of the utility model is can modify grating with rate optical grating point for a change, makes that so the striped adjacent to this optical grating point draws a straight line, and also just makes striped still possess continuity through the border of adjacency.

Description of drawings

Figure l is a known RP matrix grating hologram sheet system schematic;

Fig. 2 is another known RP matrix grating hologram sheet system schematic;

Fig. 3 is another known RP matrix grating hologram sheet system schematic;

Fig. 4 (a) is transmitted the first preferable embodiment synoptic diagram of laser beam by liquid crystal panel for the utility model utilization polarization spectroscope and reflection;

Fig. 4 (b) is for to improve Fig. 4 (a) optical system synoptic diagram with the not specific exponent number light beam of baffle plate filtering;

Fig. 5 (a) one has the baffle plate synoptic diagram of square perforate;

Fig. 5 (b) is for showing through Fig. 5 (a) baffle plate laser beam synoptic diagram after fourier transform;

Fig. 6 is a light beam graph position synoptic diagram on the liquid crystal panel;

Fig. 7 (a) is a grating point diagram between striated pattern identical on the known recording materials;

Fig. 7 (b) is that adjacent gratings point constitutes continuous bar graph on the recording materials;

Fig. 8 penetrates the liquid crystal panel thunder laser beam second preferable embodiment synoptic diagram for the utility model places the liquid crystal panel rear to produce one LASER Light Source;

Fig. 9 replaces Modulation and Amplitude Modulation the 3rd preferable embodiment synoptic diagram for the utility model utilizes phase modulation (PM);

Figure 10 has opened focus point to produce big optical grating point synoptic diagram from recording materials for the utility model.

Label among the figure:

Embodiment

Fig. 4 (a) is the front view of the first preferable embodiment optical system of the utility model.Be parallel to the laser beam 402 incident polarization spectroscopes 403 of optic axis 401 together, these spectroscope 403 reflector lasers are to display panel 404.This display panel 404 can adopt the display panels that often applies to image projecting system to accomplish, and the voltage that puts on display panels can change its inner liquid crystal molecule direction.When a linearly polarized photon passed through layer of liquid crystal molecule, its polarization characteristic can change because of the direction of liquid crystal molecule.Based on above-mentioned principle, when such laser beam passes through an analyzer (analyzer) or polarization spectroscope, can utilize the voltage that puts on liquid crystal panel to control the brightness of this laser beam.

Shown in Fig. 4 (a), zone 405 and 406 is that the scope that applies driving voltage is arranged on the display panels 404.Therefore the laser beam that is returned by 405 and 406 reflections of zone on the LCD 404 can be earlier through spectroscope 403, and advances towards lens 407.Also can go back all the other laser-bounce in the zone that does not apply driving voltage on the liquid crystal panel 404, this part laser can be by the direction at spectroscope 403 reflected back LASER Light Sources place, and it can be presented at twice laser 420 and 421 central shaded areas.This twice laser 420 and 421 is to produce different circular light beams by liquid crystal panel 404, through baffle plate 408 opening post-concentration Jiao on recording materials 409, because of interference effect makes twice laser beam 420 and 421 need raster graphic in recording materials 409 formation.Recording materials 409 can move to next optical grating point precalculated position behind optical grating point of record, so just can write down whole optical gate matrix step by step.Fig. 4 (b) is the side view of the utility model optical system, laser multistage light wave behind diffraction that its expression liquid crystal panel 404 sends, and this multistage light wave passes spectroscope 403 and is focused on the recording materials 409 by lens 407.Produced by liquid crystal panel 404 diffraction in respect of 410,0 grade of light wave of 1 grade of light wave 411 and-1 grade of light wave 412, wherein the light wave of some progression is filtered by perforate baffle plate 408 on the right.Just 0 grade of light wave 411 and-1 grade of light wave 412 are blocked, and have only 1 grade of light wave 410 to be focused on the recording materials 409 by lens 407.This kind system is suitable for not the image at optics of lens shaft position record.

In the utility model first preferred embodiments, liquid crystal panel 404 is to be used to change laser shape on the recording materials 409, and this laser beam shape is to be same as at recording materials 409 to set the raster graphic Fourier transform.The effect of lens 407 such as same fourier transform lens can produce the raster graphic of setting.

For example, if optical gate matrix need be as the square laser of Fig. 5 (a), liquid crystal panel 404 need present figure such as following formula one:

------formula one

Fig. 5 (b) shows that formula one changes situation, and wherein cosine function

can keep product term

phase angle information in the function

.By difference and function

and proportional relation before the liquid crystal panel 404 reflection twice laser waves, wherein

$x_1=\frac{D}{2}\cos \mathrm{\ω},$ $y_1=\frac{D}{2}\sin \mathrm{\ω}$

$x_2=\frac{-D}{2}\cos \mathrm{\ω},$ $y_2=\frac{-D}{2}\sin \mathrm{\ω}$

ω system expression display panel twice laser beam direction is as shown in Figure 6 again.601 and 602 in the figure represents a function?

and?

location on the display panel.As as everyone knows, lens 407 are for also producing a Fourier transform before the laser wave.Therefore be proportional to formula two in the move the capital to another place system that distributes of lens 407 focusing surfaces:

--------formula two

F wherein ₁(u v) is f ₁(x, Fourier transform y).Can formula two be rewritten as formula three then:

----formula three

Shown in formula three, the optical grating point shape can be by | F ₁(u, v) | ²One determine that and fringe spacing is λ F/2D, and striped will be with respect to the recording materials rotation of coordinate Angle.May command of phase angle difference is in abutting connection with the continuity of optical grating point striped.

Shown in Fig. 1 to Fig. 3 optical gate matrix system, optical grating point is to be made up of a lot of striped, and each striped is again to be made up by a lot of point or pixel.Recording materials can move to produce complete raster graphic step by step; But adopt identical figure to have problems at different optical grating points; Be exactly when optical grating point spacing and stripe direction are in full accord; Adjacent gratings point border striped is discontinuous usually, and shown in Fig. 7 (a), striped 701 and 703 can't draw a straight line.Here it is, and still there is basic restrictive condition at present in all optical gate matrix systems.

The adjacent optical grating point of the utility model can be produced by out of phase difference twice laser; Its result can make the optical grating point with identical grating space and direction adjacency have continuous striped; The grating of being formed is processed just like positive, and unlike combining by many little gratings.Fig. 7 (b) shows striped through still keeping good continuity in abutting connection with optical grating point, and just striped 702 and 704 aligns each other.

The utility model first embodiment can further explain through a plurality of optical parametric fundamental relation formulas.The width of supposing laser beam 405 and 406 is W, and D is twice laser beam 405 and 406 spacings, and the focal length of lens 407 is F.This twice laser beam 405 and 406 equals in recording materials incident angle (incident angle): $\mathrm{\θ}={\mathrm{Tan}}^{-1}\left(\frac{D}{2f}\right).$

The interference fringe spacing is T=λ/2sin θ again, and the size of optical grating point then is δ=λ F/W on the recording materials.

Make F=10mm, W=2mm and λ=0.5 μ m, can obtain the optical grating point size and be δ=2.5 μ m.Image on recording materials is to be made up of multiple size (resolution) optical grating point, and is that the liquid crystal panel display graphics is formed according to hole shape again through Fourier transform.One common liquid crystal panel display graphics can be represented by formula four:

--------formula four

When two figures 602 and 601 distance B on liquid crystal panel is 5.16mm, the spacing of the striped on these recording materials then can equal 1 μ m.

Fig. 8 is the synoptic diagram of the utility model second preferable embodiment.Liquid crystal panel 802 can let light beam penetrate and mistake.When incident beam 801 arrived liquid crystal panels 802, the center divided beams can pass active area 805 and 806 and forward through polarization spectroscope 803, and other light beam then forms a light beam 804 by spectroscope 803 refractions after the active area not passing.Only remaining 1 grade of light wave of these twice scioptics 807 and baffle plate 808 light beams and recording materials 809 generation effects.The second preferable embodiment principle of work is with all identical shown in Fig. 4 (a).

Fig. 9 is the utility model the 3rd preferable embodiment synoptic diagram.This embodiment liquid crystal panel is a reflection type optical element, and its structure and Fig. 4 (a) are similar.One incident beam 901 is by polarization spectroscope 903 guiding liquid crystal panels 902, and zone 905 and 906 provides and needs the figure Fourier transform.Turn back spectroscope 903 and form twice and penetrate out light beam of folded light beam, this twice light beam accumulates on the recording materials 909 through lens 907 and baffle plate 908 at last.Its do not exist together for this embodiment baffle plate 908 be to let 0 grade of light wave pass through.

In the 3rd embodiment, liquid crystal panel 902 is as phase modulation component, and being different from the embodiment of front is as the Modulation and Amplitude Modulation element.The light beam that returns via liquid crystal panel 902 refraction produces phase-shifted, this phase shift with put on the proportional relation of driving voltage on liquid crystal panel 902.Final liquid crystal panel 902 has just become a phase-modulator (modulator), and the liquid crystal panel of front embodiment then is a kind of amplitude modulaor.When liquid crystal panel 902 presents

figure, its reflected light characteristic can be expressed by formula five:

---------formula five

The intensity distributions of optical grating point is proportional to formula five fourier transform formulas on the recording materials only has the phase change holography to can be described as kinoform (kinoform) formula hologram sheet partially; It is characterized by only has 0 grade of light wave can produce diffraction; Therefore diffracting effect can just have only few part light to dissipate up to 94% in theory.Because liquid crystal panel 902 is phase-modulators, all incident lights can go back in its surface reflection.905 and 906 outer areas apply a linearity and differ in the zone, therefore cause this area Returning beam 904 to understand diffraction and depart from lens 907 optic axises, and baffle plate 908 is exactly to be used for filtering to depart from lens 907 optic axis light beams.

Figure 10 is the utility model the 4th preferable embodiment synoptic diagram.Incident laser light beam 1001 is directed to liquid crystal panel 1004, and some is similar to Fig. 4 (a).Yet do not exist together for liquid crystal panel 1004 figures can make reflected light disperse, focus on the back of recording materials 1009 then by lens 1007, form a bigger optical grating point.This spread reflection light is as being produced by two electric light sources 1005 and 1006, and penetrates spectroscope 1003 and go out, and the light wave of specific progression is not then filtered by baffle plate 1008.

In this embodiment; Liquid crystal panel 1004 produces figure system and is proportional to

wherein B (x; Y) be definition beam shape item; * represent inferior convolution (convolution) sign of operation of its left side and the right item; Quadratic phase item

is that representative is the slim lens of Z with the depth of focus in the cosine function parantheses; (x y) is the function of decision shape of interference fringe to φ again.Produce like figure square in the previous embodiment, (x y) will be made as function B

Because the quadratic phase item does

So on another plane of departing from lens 1007 focussing planes a little, these two plan ranges are δ Z=F by liquid crystal panel reflected light focus ²/ Z.The overlapping size of light beam is about δ=δ Z (F/W)=F on lens 1007 focussing planes ³/ ZW, relational expression can show that the quadratic phase item can control the optical grating point size thus.For example, F=20mm, W=1mm and δ=0.04mm, depth of focus Z then equals 200m in the quadratic phase item.The utility model need not change the distance of 1007 on recording materials 1009 and lens, just can access a bigger optical grating point.The optical grating point intra-striate is by six definition of formula:

$I\left(x\right)={\left[\mathrm{Sin}(\frac{2\mathrm{\π\; x}}{T}+{\mathrm{\φ}}_2-{\mathrm{\φ}}_1)\right]}^2=\frac{1}{2}[1+\mathrm{Cos}(\frac{4\mathrm{\π\; x}}{T}+{\mathrm{\φ}}_2-{\mathrm{\φ}}_1)]$ --------formula six

Wherein

parenthetic phase term can change optical grating point intra-striate shape, and makes adjacent gratings point intra-striate have continuity.

The advantage of the utility model can be put in order as follows:

1. utilize liquid crystal panel modulated beam of light phase place and amplitude, therefore do not need dimmer (shutter) or attenuator (attenuator).

2. the distance B of twice light beam can be in order to fringe spacing on the controlling recording material on the liquid crystal panel.

3. luminous point size and recording materials glazed thread shape can (x, y) function be controlled through control liquid crystal panel f.

4. (x, y) phase differential

can make adjacent gratings point interference fringe keep continuously to function f.

5. the optical system parameter adjustment all can be accomplished via the control electronic component.

The utility model technology contents and technical characterstic disclose as above, still possibly do based on the utility model teaching and announcement and allly do not deviate from the replacement of the utility model spirit and modify yet be familiar with this technological personage.Therefore, the utility model protection domain should be not limited to embodiment announcement person, and should comprise various do not deviate from the utility model replacement and modifications, and is contained by following application utility model scope.

Claims (5)

1. optical gate matrix formula register system can comprise with the raster graphic projection on recording materials:

An Electronic Display Panel;

A laser instrument, wherein this Electronic Display Panel of beam of laser beam direction;

A polarization wave filter is arranged between Electronic Display Panel and recording materials, and its permission is shone and sent specific polarization light in this Electronic Display Panel laser instrument and pass through;

A controller is connected in this Electronic Display Panel, and can drive this Electronic Display Panel and show many patterns picture, and produces at least twice and separate output beam;

A slice baffle plate can allow the specific exponent number of this output beam to pass through;

One lens can focus on this recording materials with this output beam, and this output beam forms raster graphic on these recording materials because of interfering with each other.

2. a kind of optical gate matrix formula register system according to claim 1, it is characterized in that: said Electronic Display Panel is a liquid crystal panel.

3. a kind of optical gate matrix formula register system according to claim 1, it is characterized in that: said polarization wave filter is a polarization spectroscope.

4. a kind of optical gate matrix formula register system according to claim 3 is characterized in that: laser beam system reflexes to this liquid crystal panel by this polarization spectroscope, and reflexes to this polarization spectroscope by this liquid crystal panel again.

5. a kind of optical gate matrix formula register system according to claim 1, it is characterized in that: it comprises a unpolarized spectroscope in addition, is used for this this liquid crystal panel of laser beam guiding.

Images