CN102458753A - Optical system for direct imaging of light markable material - Google Patents

Abstract

An imaging system. An array of light sources and an array of lenses corresponding to the light sources and having optical axes substantially parallel to one another are provided. The lenses produce collimated output beams. An afocal optical relay having an optical axis substantially parallel to the optical axes of the lenses is also included, the array of lenses being positioned relative to the afocal optical relay so as to form an optical system that produces an image of each collimated output beam on an image plane, each image having a prescribed depth of focus and spot size. The light sources preferably are lasers producing an array of respective laser beams having high intensity and a long waist. A system for writing information on a light-sensitive label includes the imaging system. Methods of imaging and of writing information on a light-sensitive label are also provided.

Description

But the optical system that is used for the direct imaging of light marker material

Technical field

But in general the disclosed embodiment of the present invention of this paper relate to the accurate laser direct imaging field of the light mark medium that is used for printing applications; Specifically; Relate to when label will be applied to information, write the recordings label with variable article specificity information " immediately ".

The cross reference of related application

The application is the U.S. Patent application No.11/511 that submits to and announce as the open No.2007/0068630 of United States Patent (USP) on March 29th, 2007 on August 28th, 2006,103 part continuation application, said U.S. Patent application No.11/511; 103 require in the temporary patent application No.60/789 of submission on April 4th, 2006; The temporary patent application No.60/712 that on August 29th, 505 and 2005 submitted to, 640 priority, and be the U.S. Patent application No.11/069 that submits on March 1st, 2005; 330 (is United States Patent(USP) No. 7 now; 168,472) part continuation application, said U.S. Patent application No.11/069; 330 require in the temporary patent application No.60/549 of submission on March 3rd, 2004,778 priority.

Background technology

Automatically industry is significant to mark to goods, and what in goods industry, become common practice is, comes each part goods of mark with the specific information of some article, and these information are to print with the form of for example text or bar code.Information about goods can comprise for example, whether product type, size, harvest date, original producton location and this goods are organic.In detail, become desirablely with each article of price inquiry (" PLU ") labelled notation, this can be convenient to the retailer and operates apace and fix a price for goods exactly at check-out counter.Yet, in the past, for example, with " little " of indication apple products, " in " or different PLU numbers of the size of " greatly " sign come tagged items, the marking machine of needs three platform independent, three kinds be label design and three label stocks independently.Therefore, hope can be applied to variable, programmable information to be the special goods label of individual items immediately, thereby only needs single marking machine and only single (part blank) at least label design.The title that more backgrounds of relevant this method are found in Hirst of issuing on January 30th, 2007 etc. is the United States Patent(USP) No. 7 of Method and Apparatus for Applying Variable Coded Labels to Items of Produce; 168; (hereinafter being called " Hirst ") 1 hurdle 11 in 472 walks to 2 hurdles, 45 row; Wherein all disclosure is incorporated this paper into by reference at this; The title that also is found in the Griffen that announced on March 29th, 2007 etc. is the 2-21 section of the open No.2007/0068630 (hereinafter being called " Griffen ") of U.S. Patent application of Multi-Layer Markable Media and Method and Apparatus for Using Same, and its whole disclosures are also incorporated this paper at this by reference.

As disclosed in Hirst and Griffen, the information of using light beam on label, directly to write the record variation is desirable.Accomplish that with rapid, unanimity and the effective mode of cost this point also exists challenge, these challenges derive from the relation between marking machine, label material and the beam optical device.In detail, be desirable to provide high-power light beam, so that reduce the required label time for exposure.It would also be desirable to provide the light beam that on label, has long depth of focus,, focus on image and still can be write record on label even so that guaranteeing label position possibly change with respect to the nominal image surface of beam optical device significantly.Also further hope the light beam aberration is minimized, provide diffraction limited light beam image practically with approaching as far as possible on the image surface.

In the United States Patent(USP) No. 6,084,706 (hereinafter being called " Tamkin ") of Tamkin, describe a kind of directly writing and record method of patterning and device with laser beam.Tamkin discloses a kind of thrihedral reflector afocal optical system, and wherein speculum can have non-sphere (for example, parabolic, hyperbolical or ellipse) surface or spherical surface.Compare with the system based on lens, such total reflection structure (using speculum to replace lens fully) has been realized high-level ground efficiency of transmission, and in the system based on lens, lens medium absorbs significant luminous energy inevitably under some wavelength.

In general, the afocal optical system is the optical system that hypothesis object and image are positioned at infinity.Incident is parallel with the light of outgoing afocal optical system.Instance comprises binocular and telescope, wherein, though image is amplified by optical system, is focused on by eyes.Magnifying power can make the size of image increase or reduce (being that fraction is amplified), and this depends on that whether amplification factor is respectively greater than 1 or less than 1.The afocal optical system can have focus optical system to form through making up two, so that the back focus of first system overlaps with the front focus of second system, thereby produces the whole system that does not have effective focal length.Tamkin has described some embodiments of thrihedral reflector afocal system, respectively has different magnifying powers.

In Tamkin, reach eight independently light beams with single lasing light emitter and a beam splitter generation, make said light beam pass an optical system then to produce the image of one 15,000 pixel, pixel size is in the scope of about 1-10 micron.Come relaying to propagate scanning light beam with the thrihedral reflector afocal system with required magnifying power and minimal power loss then.Yet, the power of single laser is divided into a plurality of scanning light beams reduces the unit interval greatly and be delivered to the power that object (such as label) is given anchor point, thereby influence the output quantity of direct scanning system.In addition, Tamkin does not solve the challenge that realizes required long depth of focus in automatic " immediately " Mk system.

As disclosed in the United States Patent(USP) No. 6,640,713 of Landsman, in directly writing the record application, can use many diode laser matrixs, rather than single laser is divided into a plurality of light beams.Yet, only if but diode laser matrix can be positioned over immediately near the light mark medium, as the situation of writing the recordings label immediately, be still a challenge otherwise laser is delivered to medium effectively.

The United States Patent(USP) No. 6,177,980 (hereinafter being called " Johnson ") of Johnson discloses a kind of optical system that is coupled micro lens element or lenslet array, and it has the image projecting system of a low resolution, the micro-lithography application of the big visual field.Johnson utilizes grating light valve or micro reflector array to regulate the diffusion light beam of single diode laser light source.Then, be focused into the some image of wide spacing by lenslet array through the light that overregulates.Beam spacing between the lenslet of Johnson is wideer than focus point substantially, this need be inappropriate at a high speed, online, reel is handled writes the record strategy.Though Johnson discloses the purposes of afocal system in directly writing the record application that has lenslet array; But it does not solve and is present in the above-mentioned challenge of directly writing in the design of record imaging system; Promptly wherein the position of image plane possibly change in time significantly, and the initial mass of light beam is poor as the output of multi-mode diode laser, and the lighting power of light beam must be high; And need a kind of form compact, the effective optical module of cost.

Therefore, but need that a kind of wherein, the position of medium can change significantly through on light mark medium, directly write the improved optical system that is used for photosensitive printing of record with laser beam, the lighting power height, and said optical system answers compactness and cost effective.

Summary of the invention

The present invention discloses a kind of imaging system.

In first aspect, said imaging system comprises array of source, lens arra, and said lens arra is corresponding to said light source and have parallel substantially optical axis.Said lens produce the collimation output beam.The present invention also comprises a kind of afocal optical repeater; It has the optical axis parallel substantially with the optical axis of said lens; Said lens arra is located with respect to said afocal optical repeater; So that be formed on the optical system that produces the image of each collimation output beam on the image plane, each image has the depth of focus and the spot definition of regulation.

In second aspect, said imaging system comprises laser array, and this laser array produces the array of laser beam separately.Second aspect further comprises lens arra, and it is corresponding to said laser array, and is arranged in the select location place with respect to said laser array, so that produce the magnified image of laser beam separately.A kind of optical repeater is arranged in the select location with respect to said lens arra, so that produce the image of laser beam separately at image plane, wherein said image satisfies selected fuzzy criterion.

The present invention also discloses a kind of system that is used on light sensitive tag, writing record information.Said system comprises the array of source that produces beam array, and corresponding to said light source to be used for lens arra with the beam direction image plane.Provide a kind of being used for that light sensitive tag is positioned at the labelling apparatus on the image plane.The optical repeater that is arranged between array of source and the labelling apparatus produces the light beam image that amplifies on light sensitive tag, thereby makes the label exposure also and then with pattern write record on label.

The present invention also discloses a kind of method that on light sensitive tag, forms images and write record information.

Should be understood that it is as the means that are used for confirming substantially the content of follow-up accompanying drawing and detailed description that this general introduction is provided, and be not intended to limit scope of the present invention.Through combining accompanying drawing to consider together, will should be readily appreciated that the object of the invention, feature and advantage to following detailed description.

Description of drawings

According to following detailed description and combine accompanying drawing, will should be readily appreciated that embodiment of the present invention.For the ease of describing, identical reference number is represented identical structural detail.Embodiment of the present invention mode is by way of example explained, rather than is limited to the figure in the accompanying drawing.

Fig. 1 is the perspective view of automatic goods labelling apparatus, and wherein laser beam is used on the multilayer heat-sensitive label, writing the record coded message.

Fig. 2 is the side view of the part of bellows, and said bellows is attached to have a label, and with the optical axis alignment of the preferred embodiment of the disclosed optical system of this paper.

Fig. 3 is produced and by the diagrammatic side view of the array of the laser beam of microlens array calibration by the laser diode light source array.

Fig. 4 is the schematic end view of geometry of the customization microlens array of exploded view 3.

Fig. 5 is the detailed end view of the lens component of the inner single lenslet of the microlens array showed among Fig. 3.

Fig. 6 is the side cross-sectional view of the inner single lenslet of the microlens array showed among Fig. 3.

Fig. 7 is the layout of a preferred embodiment of the disclosed optical system of this paper, and it shows the situation of exemplary rim ray when system is passed in its propagation from single laser diode.

Fig. 8 is the expansion side view of the optical system of Fig. 7, and it only shows three power supply speculums, wherein, and the concave surface of first speculum and the 3rd speculum, and the convex surface of second speculum is visible.

Fig. 9 is the thin lens sketch map of thrihedral reflector afocal part of the optical system of Fig. 7, its show send from single, the representative laser diode at diode array center and propagate and pass the chief ray and the rim ray of whole optical system.

Figure 10 is the side view of Gaussian laser beam waveform, and its display light beam width is with the change of propagating.

Figure 11 is the wave optics diagram of the multi-mode operation of diode laser to the influence of gauss light beam waist, and said Gaussian beam is being produced by laser when lenslet is calibrated.

Figure 12 is the curve map that the width of laser beam and the distance that leaves LASER Light Source are functional relation.

Figure 13 is the curve map that laser beam output position with a tight waist and its input position with a tight waist are functional relation.

Figure 14 is that the explanation laser beam spots is with respect to the out-of-alignment diagrammatic sketch of target labels.

Figure 15 is the reproduction of the optical layout figure of Fig. 7, and it further is illustrated in the storing of label edges sensor of input place of afocal optical repeater.

Figure 16 is the sketch map at the dichroic beam splitter of the label edges sensor internal of Figure 15.

Figure 17 is the reproduction of the figure of optical layout of Fig. 7, and it further shows the storing that is used for the detector of laser power monitoring between afocal optical repeater alignment epoch.

The specific embodiment

Carry like preceding text, use and directly to write the advantage that the record laser system produces the goods label and be: label information can be according to the variation of goods (such as size) and " immediately " change.For example, individual other fruit can be after measuring mark immediately, rather than before a collection of fruit is classified by size at mark.In an embodiment of the goods labeling method of Hirst and device (with reference to and by reference integral body incorporate this paper into); Obtain a label by bellows from a removable label; With its be exposed to light beam so that the pattern of light pass label write the record and write on the front surface of recording label, by bellows it is applied to the individual part goods of goods then.(Hirst, Figure 1A and 1B; Hirst, 3 hurdles, 45-59 is capable).

Such method and apparatus, and the label that supplies its use bring lot of challenges to design is write record with effective and efficient manner on label optical system.A challenge is to produce because of following: when bellows rotates to when individual other label is applied to the position on the goods, the lengthwise position of label possibly change significantly.Therefore, the uniformity that writes on the spot definition on the label depends in part on the depth of focus of light beam, and depends in part on the quality of light beam.Another challenge is to produce because of following: require light beam to have enough intensity so that photosensitive medium fully makes public usually.Another challenge is suitable in form, produce that depth of focus is long relatively, strong high-quality light beam in the effective assembly of cost.

Turn to Fig. 1, labelling apparatus 40 is used for measuring label 41 and label 41 is applied in production line 44 on the product processed 42 immediately.In the present embodiment, collect size or other data about product 42 through sensor 46, and said size or other transfer of data about product 42 are arrived laser code device 48, this device sends the laser beam 50 with optical axis 52.Labelling apparatus 40 is transferred to the blank tag 41 of backing sticker on the bellows top 56 of bellows 58 of rotational fixation from the reel 54 of blank tag 41.After obtaining label 41, bellows 58 remains on the appropriate location through the low pressure of keeping at the interface between label 41 and bellows top 56 with label 41.When bellows 58 along curved path 59 during to production line 44 rotation, label 41 (being preferably the thermo-color type of multilayer) through laser code device 48 optical axis 52 and be exposed to laser beam 50.Laser beam 50 is directed to and propagates and pass optical adjustment device 60 (such as the lens combination of signal displaying in Fig. 7).Optical adjustment device 60 is regulated laser beams 50, records on the label 41 so that it is suitable for the label information of coding directly write exactly.When the bellows 58 of rotational fixation continued rotation, bellows 58 was applied to label 41 on the product 42, and the circulation that repeats to describe just now.

In the commercial application of such goods Mk system, great challenge is by causing to the needs of accurate timing, process velocity and on moving target, focusing on the needs of image exactly.For example, the labelling apparatus that 114-120 section (said disclosure is incorporated at preceding text by reference) is described in Griffen can keep the goods output of 720 goods of per minute.Has big depth of focus so hope the laser beam image that is incident upon on the label 41; So that image can keep focusing on and during bellows action as much as possible, keep its magnifying power, as in the Fig. 6-8 of Griffen and 63-64 section indicated (wherein said disclosure is incorporated at preceding text by reference).Yet, in order to make the relatively large area (approximately 20mm is wide) of high power exposure label 41, the depth of focus that possible loss is certain.For example, provide in 0119 and 0120 of Griffen section and be applicable in the single laser diode light source of such goods Mk system or the characteristic of diode laser matrix.These characteristics comprise between 800 and 1600nm between wavelength and the power level of the about 500mW of each laser diode.

As in Fig. 2, showing; Bellows 58 in the automatic Mk system described in Figure 1A-1B of preceding text and Hirst and Fig. 6 of Griffen-8; Have the pneumatic bellows top 56 that is attached to light sensitive tag 41, it obtains label from backing material (not showing), makes label move through the optical axis 52 of beam adjuster 60; And it is applied on the goods, such as preamble explanation.Griffen has described one of the light sensitive tag 41 especially embodiment of advantageous embodiment in Fig. 9 A-9B and 65-66 section, it comprises the three-decker (said disclosure is incorporated at preceding text by reference) of showing among Fig. 2.Label 41 preferably has the translucent base layer 64 of translucent adhesion coating 62, substrate, middle light absorber layer 66 and thermochromic layer front side layer layer 68; These layers are arranged by said order; So that when the dorsal part of light beam irradiates label 41, light beam arrives absorber layers 66 through adhesive coatings and basalis 64, and radiant energy is transformed into heat in this layer; No matter it is wherein from the dorsal part exposure of label then, causes that all thermochromic layer 68 changes color.A kind of like this complicacy of different materials, optical system that multilayer labels itself can be regarded as being characterized as point spread function of comprising, this point spread function are different from the point spread function that characterizes optical adjustment device 60 and are replenishing of this point spread function.When bellows 58 is advanced when passing optical axis 52; Label 41 along the position of optical axis 52 along with the time changes; This mainly is the inconsistency owing to bellows 58 circumferentially extendings, but also is owing to rotation, the variation of the surface configuration of label 41 and other factor of bellows 58 along curved path 59.This variation of label 41 positions is represented by the Δ z among Fig. 2.Therefore, record image clearly in order on label 41, as one man to write, the depth of focus of optical system should be the same with Δ z at least long.

Remove whole by reference Hirst that incorporates into and the disclosure of Griffen; Comprise outside those the specific parts like the preceding text narration; Disclosure of the present invention comprises a kind of new optical system design of the function of carrying out laser code device 48 and optical adjustment device 60, and said optical system and the combination of goods labelling apparatus 40 automatically.Said optical system comprises the afocal optical repeater that the laser spot of application-specific (such as the goods tag application) needs is satisfied in the laser diode light source array, the microlens array of collimated laser beam, and adjusting laser beam separately and the generation that produce the laser beam array.

Fig. 3 shows the closely side view of laser diode and lenticule array of source parts 90.Array of source parts 90 comprise the array of source assembly 100 and lens arra assembly 105 of selected distance at interval.Array of source assembly 100 comprises power supply (showing) and (according to a preferred embodiment) diode laser matrix 102, and it produces along the array of the laser beam 104 of parallel substantially axle propagation.Laser diode 102 is addressable, programmable light source preferably, has the next power output of regulating separately of electric current that can offer each diode in the array through change.The laser that is produced by array of source 100 preferably has the optical maser wavelength of about 980nm, and the nominal power output level of each laser diode of about 300 laser diodes 102 approximately is 500mW, and laser diode 102 is about 125 microns at interval.Diode laser matrix type described in this paper can be from the OSRAM Opto Semiconductors of (for example) California Sen Niweier, and the Laser2000 GmbH of Inc. and Munich, Germany obtains.Lens arra assembly 105 preferably comprises collimation microlens array 106, and element wherein is to have the independent lenslet 107 of parallel optical axis substantially, so lenslet 107 produces the collimation array of laser beam 104.

Fig. 4 shows the end-view of preferred embodiment of the microlens array 106 of customization, and said microlens array has the array length 202 of about 35mm and the about array-width 204 of 5mm.Microlens array 106 is by the device such as the customization of the Rochester Photonics Corporation of Corning manufactured in New York.Microlens array 106 is to construct through the repetition linear patterns of microlens array elements or lenslet 107 to make.Lenslet 107 layouts close to each other, the spacing distance 208 of Center-to-Center approximately is 125 microns, forms to have the one dimension vertical row 210 of about 280 lens.Fig. 5 has showed the amplification end view of single micro lens 107, is independent transparent lenticules 212 in the inside center of each lenslet 107, and it has about 500 microns lens diameter 214.Lenticule 212 usable polymers, collosol and gel duplicate, or are etched in the substrate of glass.In a preferred embodiment; With a pair of clear aperature formula (being transparent), non-sphere, convex surface, conic section micro polymer lens 212 control aberration, rather than use single entry cylindrical lens design common in the existing laser array system to control so as to the single face array.

Fig. 6 is with the single lenslet 107 of shown in cross section.Lenslet 107 is that in fused silica (glass) substrate 216, to be made for about 1mm thick, and refractive index is about 1.45.Side substrate 216 is two directional light polymeric base layers 218, and approximately 50mm is thick, and refractive index is about 1.54.Each micro polymer lens 212 preferably has non-sphere, hyperboloid shape, and through being shaped so that laterally protrude about 40 microns height 219 from the front surface 220 or the surface, back 222 of polymeric base layer 218.The center of each lenslet 107 in vertical row 210, one two hyperboloid polymer lens 212 is from front surface 220 protrusions, and one of lenses 212 is protruded from surface, back 222.Therefore, the independent laser beam of propagating from left to right 224 on the plane of vertical incidence microlens array 106 can be through a pair of hyperboloid lens 212 in Fig. 6, and through be clipped in said lens between polymeric base layer 218 and substrate of glass 216.

Fig. 7 displaying is positioned the total reflection afocal optical relay system 300 between object plane 301 and the image plane 302, and array of source parts 90 are positioned at said object plane 301 places, and said image plane 302 is with target labels 303 co.Perhaps, though preferred full reflected system so that the minimize power losses in the transmission it should be understood that under the situation that does not break away from the broad principles of the present invention, optical relay system 300 can be refrangible, it comprises lens and non-reflective mirror.

The image output 304 of laser beam array 104 forms on image plane 302, and image 304 comprises independent laser beam spots, and each luminous point has spot definition 308.Viewpoint from geometric optics; The light ray that comprises each laser beam 224 that is produced by the given laser diode of array of source 100 102 is by 107 calibrations of given lenslet array; Said then collimated light beam is propagated and is passed a series of smooth speculum 310-320 (some of them are supplied power), on image plane 302, to produce the image output 304 that amplifies slightly of said laser beam spots.Because incident of chief ray parallel optical axis and outgoing afocal optical repeater system 300, so magnifying power is with defocusing and change.Depth of focus is strictly to be confirmed by the wave optics characteristic of the focused laser spot on the last image plane.This is an advantage of the optimum decision system design showed.

When the ray propagates that comprises laser beam 224 is passed optical relay system 300; According to reflection law; They are reflected each speculum of mirror 310-320 along the light path deflection of bending, and said reflection law regulation is with respect to the normal at mirror surface pip place, and angle of reflection equals incidence angle.The preferably smooth speculum of being showed of preceding two speculums (310 and 312), rather than concave surface or convex surface.Therefore, they do not change the waveform of light beam 224; On the contrary, they are with the mirror system of said beam direction inclination.Speculum 314,316 and 318 preferably comprises the sphere power supply speculum of thrihedral reflector afocal system 319.In order further to control aberration, use element afocal system rather than dual-element system.Output reflector 320 preferably becomes the flat mirror at angle, so as on image plane 302 with the laser beam 224 target goal labels of regulating 303.When minification becomes when causing NA to surpass 0.05 greatly, speculum 314-318 is can right and wrong spherical.Thrihedral reflector system 319 is used for making aberration to minimize, so that it is limited rather than aberration is limited to make systematic function remain diffraction.

With reference to figure 8, it shows the front view of the expansion of thrihedral reflector afocal system 319, and in a preferred embodiment, first speculum 314 and the 3rd speculum 318 preferably increase the just power supply speculum of image output 304 sizes; Speculum 316 preferably reduces the convex surface of image output 304 sizes, negative power supply speculum.Therefore, in order to produce the required image output 304 with required spot definition 308, speculum 314-318 cooperates and regulates laser beam 224.The principal character that comprises the optical system design of microlens array 106 is with regard to the array element interval, to remove the point-like attribute of laser diode emission, thereby each laser beam 224 is enough spread, so that form overlapping luminous point at image plane 302.Microlens array 106 makes the numerical aperture (NA) of each laser diode 102 outputs be reduced by at least about 10 times effectively, thereby relaxes 300 designed constraints to afocal optical repeater system.

Answer emphasis to be noted that, even object plane 301 or image plane 302 displacements, afocal system is still kept the magnifying power of image output 304.This is important, because when the displaced on bellows top 56 is passed depth of focus, because rotation, vibration and other machine errors can not change or become distortion in the lateral attitude of directly writing record operating period image.

The final magnification of image output 304 can be adjusted through the relative position that changes the inner speculum of afocal optical repeater system 300.The scheme of suitable afocal optical repeater system 300 is detailed in the table 1, and through Fig. 9 explanation.

Optical element	The position, mm	Radius of curvature, mm
			Object	Infinity	N/A
The 1st speculum of supplying power	-190.97	-80.78 (concave surfaces)
			The 2nd speculum of supplying power	-86.54	(21.19 convex surface)
The 3rd speculum of supplying power	-159.42	-156.67 (concave surfaces)
			Image	Infinity	N/A

Table 1: the scheme of afocal optical repeater system 300.

In Fig. 9, the figure of the expansion of laser beam 224, minimizing linear light line tracking illustrates in greater detail the optical characteristics of said preferred embodiment.Fig. 9 displaying is positioned at the thin lens of the lenslet 107 of object plane 301 and representes; The first power supply speculum 314 has focal distance f 1; The second power supply speculum 316 has focal distance f 2; And the 3rd power supply speculum 318 has focal distance f 3, and they distribute optical axis 52 image outputs 304 along optical adjustment device 60 with said order.Speculum 314-318 forms afocal system; Yet object in fact is not to be positioned at infinity.

Fig. 9 shows the chief ray 321 of representing laser beam 224, and it is incidence reflection mirror 314 from the left side, and is parallel with optical axis 52, and from speculum 318 outgoing to the right, also parallel with optical axis 52.Each the such chief ray that is produced by each laser diode 102 proceeds to final image 304 along the path as representational chief ray 321 of passing optical repeater afocal system 300 subsequently.Half of the width degree of rim ray 322 expression laser beams 224.In a preferred embodiment, fraction takes place amplify, so bigger than the laser beam spot size 308 at the output point of afocal system at the laser beam width of the incidence point of afocal system.

A key character of the disclosed preferred embodiment of this paper is that laser diode source array 100 so that at image plane 302 required depth of focus and width of light beam is provided, also provides maximum luminous power with respect to microlens array 106 location simultaneously.Lenslet 107 restrictions are from the amount of the light of each laser diode 102 collections, thereby the size of the laser beam 224 of each lenslet 107 of restriction outgoing.Simultaneously, use in order to write in the record high speed imaging of using and being used for other at instant label as herein described, importantly, overlapping at image plane 302 places corresponding to the image of the laser beam spots of contiguous laser diode 102.This can produce the zone of writing record continuously on label 41, therefore any interval of writing between the record zone becomes the result who closes one or more laser diodes 102.When not having lenticule 212, with the reimaging of the luminous point on the facet on the laser diode source 102 size on image plane 302.Therefore, to be approximately that several microns luminous point compares with center to center lenslet spacing distance 208 be very little to these diameters.Use the light beam of lenticule 212 " calibration ", produce bigger luminous point from each laser, approximately the same big or small with 125 microns center to center spacing distance 208.Because, in fact should only be intercepted and captured by a lenslet 107 from the light of a laser diode source 102, actual image spot definition 308 is more smaller than spacing distance 208, and the laser beam 224 of the lenslet 107 of two vicinities of outgoing can be not overlapping immediately.Yet, can make contiguous laser beam 224 overlapping at a distance of lenslet 107 a distance, because according to formula (1), laser beam 224 is to propagate with the functional relation of distance (d).The image that therefore, will be positioned over image plane 302 is not the image of a plurality of laser beams 224 of direct outgoing lenslet 107; On the contrary, it is the image that is positioned at a distance of microlens array a distance, and contiguous laser beam 224 is overlapping fully in this distance.

Turn to wave optics, Figure 10 shows the expression more true to nature of the shape of propagating a branch of light that passes optical system.Those skilled in the art will be appreciated that; The output of laser diode 102 is Gaussian laser beam (Gaussian laser beam) 330 normally; Have focal distance f through being configured to calibrate or the lens or the power supply speculum of focused Gaussian laser beam 330; On the plane with a tight waist 332 of the image space of lens or speculum, produce with a tight waist, or minimum widith ω om.Said laser beam width ω m is the expansion of hyperbolic function relation along the light propagation axis 52 of laser beam 330 with the distance z that leaves ω om with a tight waist, so that width and ω om with a tight waist, distance z, focal distance f, wavelength X and mould parameter M are functional relation, as follows:

${\mathrm{\ω}}_m(\mathrm{\λ},{\mathrm{\ω}}_{\mathrm{om}},z,M):={\mathrm{\ω}}_{\mathrm{om}}\·{[1+{\left(\frac{\mathrm{\λ}\·z\·M^2}{\mathrm{\π}\·{{\mathrm{\ω}}_{\mathrm{om}}}^2}\right)}^2]}^5---\left(1\right)$

So, depth of focus is that acceptable fuzzy criterion is satisfied in inside with a tight waist, and is shown in figure 10 in the front side of ω om with a tight waist and the distance b of rear side.For given laser beam ω om with a tight waist, the depth of focus b of said optical system is definite by the mode volume of the width ω m of laser beam and lasing light emitter, such as its M2 value description.Therefore, depth of focus is independent of the position of afocal relay system 300 with respect to diode lenslet array of source parts 90.In a preferred embodiment of the disclosed optical system of this paper, as used in the goods tag application, equal depth of focus twice should surpass the label position variation delta z that shows among Fig. 2 apart from 2b.

Figure 11 shows when Gaussian laser beam 330 during through lenslet 107, thereby the multi-mode operation of laser diode 102 is to the laser beam width with to the influence of depth of focus b.Laser beam 338 by means of the central pattern of using beam optical device, expression Gaussian laser beam 330; And the laser beam 340 of the edge pattern of expression Gaussian laser beam 330; It is thus clear that; Compare with single-mode operation, in multi-mode operation (M2＞1), the expansion of combined laser beam 366 is along with take place to such an extent that (represented by arrow 342) more fast than the expansion of single laser beam 368 from distance z with a tight waist.This is expanded the correspondence that is accompanied by depth of focus b on image plane 302 fast and shrinks.The preferred focal length of lens of selecting is so that collect maximum light from each diode 102.Because the center to center spacing distance 208 between the array element is fixed, will collect more multiple astigmatism so have short focus lens.Yet, have short focus lens and also will produce narrow collimation output beam.Bigger focal length produces bigger luminous point, if but focal length becomes too big, and light overflows to contiguous array element, can cause too much overlapping.Usually, required focal length will be the focal length that the angle of divergence of NA and the laser beam 224 of lenslet 107 is complementary.Yet,, need these two emulative targets of balance for obtaining pinpointed focus.

According to formula 2, when lasing light emitter 100 was positioned at the front focus of lenticule 312, the maximum luminous point that pinpointed focus occurs was with a tight waist.If the focal length of selecting lenticule 312 is so that the angle of divergence of the NA of lenslet 107 and laser diode 102 is complementary; The laser beam width ω m (being image spot definitions 208 effectively at image plane 302 wherein) that is functional relation with lasing light emitter position z so is to be illustrated in the curve map of Figure 12.Laser diode source 102 needn't be positioned at the front focus of lenticule 212, but according to formula 2, is when laser diode source 102 is positioned at front focus, to occur corresponding to the maximum optical spot size 308 of minimum focus.

${\mathrm{\ω}}_{\mathrm{om}2}(z,f,\mathrm{\λ},{\mathrm{\ω}}_{\mathrm{om}},M):={\mathrm{\ω}}_{\mathrm{om}}\·\frac{1}{\sqrt{{(1-\frac{z}{f})}^2+{\left[\frac{\mathrm{\π}\·{\left(\frac{{\mathrm{\ω}}_{\mathrm{om}}}{M}\right)}^2}{2f}\right]}^2}}---\left(2\right)$

Can place each laser diode 102 so that send the front focus place that the semiconductor facet of laser is positioned at corresponding lenslet 107, thereby make the back focus place of the ω om with a tight waist of laser beam 224 at lenslet 107.Yet this position is also the most responsive to defocusing mistake.The output beam waist position d2 that is functional relation with input beam waist position d1 can calculate according to formula 3, as in Figure 13, showing:

$d_2(d_1,f,\mathrm{\λ},{\mathrm{\ω}}_{\mathrm{om}},M):=\frac{f}{1-\frac{d_1\·f-f^2}{{d_1}^2-d_1\·f+\mathrm{\π}\·\frac{{\left(\frac{{\mathrm{\ω}}_{\mathrm{om}}}{M}\right)}^2}{\mathrm{\λ}}}}---\left(3\right)$

In a preferred embodiment; In order to obtain the data of Figure 12; It is bigger that the focal distance ratio of microlens array 106 is used for the pinpointed focus of formula 2; And the focal plane position of laser beam is not to be positioned at the front focus place, thereby makes the positive approximately scope of 5mm-15mm that is pushed away microlens array 106 at the beam waist position of output place.Then, said laser beam is expanded from said position, so that contiguous light beam 224 is overlapping at a distance of lenslet a distance.Then, the image of laser beam spots is transferred to image plane 302 through non-burnt optical relay system 300.

The image output 304 of laser diode 102 has predetermined magnifying power, and said magnifying power is chosen to satisfy directly writes the pel spacing requirement that record is used.It is explained that in this embodiment, target labels 303 warps of thermo-color are located so that carry out mark at image plane 302, and need the bar code label width of 18mm, required image pixel to be spaced apart about 70 microns through an embodiment.Suppose to propagate when passing microlens array 106 and disperse about 5-10 degree that the Gaussian beam radius in output place of microlens array 106 is about 62 microns so with full duration half maximum (hereinafter being called " FWHM ") when laser beam 224.This changes into about 73 microns FWHM laser beam spot size 308 in microlens array 106 outputs place.The overall amplification of afocal optical repeater system 300 is given with the ratio of diode laser matrix spacing (in this embodiment, about 125 microns) by image pixel interval (70 microns), obtains 0.562 the factor.This factor is applied to the FWHM laser beam spot size obtains 41 microns final outgoing laser beam spot definition 308.

With reference to figure 14-16; Can be provided for the label edges sensor 350 (shown in Figure 15 and 16) at the suitable center of detection laser beam image output 304 (shown in figure 14); Wherein with respect to the target labels that is positioned on the bellows top 56, image output 304 has final outgoing laser beam spot definition 308.In a preferred embodiment, label edges sensor 350 can insert between the input of microlens array 106 and optical relay system 300.Turn to Figure 16, the 350 preferred uses of label edges sensor are made up of the red laser light beam 352 of target labels 303 reflections of multilayer thermo-color.Red laser light beam 352 uses 354 divisions of 50% dichroic beam splitter, so that half that makes ruddiness forms the reference signal 355 that turn 90 degrees partially and lead division detector 356.Second half ruddiness forms the transducing signal 358 by flat mirror 360 reflections, so that propagate along the laser beam that runs through optical relay system 300 224.When transducing signal 358 runs into target labels 303, its reflection and formation inverse signal 362.Inverse signal 362 is propagated with laser beam 224 antiparallels, oppositely runs into flat mirror 360 and dichroscope beam splitter 354 once more up to it along the bending path of optical relay system 300, and both cooperate so that inverse signal 362 guiding division detectors 356.If sensing signal 358 does not overlap with respect to target labels 303 with laser beam 224, at least a portion transducing signal 358 can not run into target labels 303 so, thereby reduce the intensity of inverse signal 362.When the intensity of inverse signal 362 and reference signal 355 comparisons, not matching indicates laser beam 224 and on target labels 303, overlaps.

With reference to Figure 17, can increase the single power detector 364 of the power level that is used for monitoring laser bundle 224 to afocal optical repeater system 300.In a preferred embodiment; Power detector 364 is the behinds that are positioned over second speculum 316; Said second speculum can be through special design having the part transmittance, thereby allow to lose and be directed to power detector 364 from a part of light (scope is 0.1% to 0.5%) of laser beam 224.

Though this paper has explained and has described some embodiment; But one skilled in the art should appreciate that; Without departing from the present invention, estimate to realize that the various alternative and/or equivalent embodiments of identical purpose or embodiment can replace embodiment illustrated and description.Those skilled in the art will should be readily appreciated that, can use very widely mode to implement according to embodiment of the present invention.The application is intended to contain any improvement or the variation of the embodiment that this paper discusses.The term that in above-mentioned specification, uses is as the term use of describing explanation with being expressed in this paper; Rather than restriction; And when using this type of term and expressing; The present invention does not get rid of a characteristic of showing and describing or the equivalent characteristics of its part, should be appreciated that scope of the present invention only defines and limits through the claims of enclosing.

Claims (58)

1. imaging system, it comprises:

Array of source;

Lens arra, it has parallel substantially optical axis corresponding to said light source, and said lens produce the collimation output beam; And

The afocal optical repeater, it has the optical axis parallel substantially with the said optical axis of said lens;

Wherein said lens arra is located with respect to said afocal optical repeater, so that be formed on the optical system that produces the image of each collimation output beam on the image plane, each image has the depth of focus and minimum spot definition of regulation.

Imaging system according to claim 1, wherein each said light source has the power output of independent variable, and said light source conditioned is so that optionally change their power outputs separately.

2. imaging system according to claim 2, wherein said light source are programmable laser diodes, and it can come to regulate separately through changing the electric current of supplying with said diode.

3. imaging system according to claim 3, wherein said light source is arranged with linear array.

4. imaging system according to claim 4, wherein said afocal optical repeater comprises a series of power supply speculums.

5. imaging system according to claim 5, wherein said power supply speculum comprises first concave mirror, second convex reflecting mirror and the 3rd concave mirror.

6. imaging system according to claim 6; The center to center that wherein said light source is compared between the said lens has the structure of point-like substantially at interval; Consequent said collimated light beam amplifies through said afocal optical repeater, so that said image comes overlapping by selected amount.

7. imaging system according to claim 1, wherein said light source is a laser diode, and said afocal optical repeater comprises a series of power supply speculums.

8. imaging system according to claim 1; The center to center that wherein said light source is compared between the said lens has the structure of point-like substantially at interval; Consequent said collimated light beam amplifies through said afocal optical repeater, so that said image comes overlapping by selected amount.

9. imaging system, it comprises:

Array of source;

Lens arra, it is corresponding to said light source, and said lens have parallel substantially optical axis, and with respect to its light source location separately, so that produce first image of said light source; And

Optical repeater; It comprises at least one power supply reflecting surface; Have the optical axis parallel substantially with the said optical axis of said lens; And with respect to said first image location of said light source, to produce amplification second image of said light source at image plane, said whereby power supply reflecting surface is used for making the power loss in the said optical repeater to minimize.

10. imaging system according to claim 10, wherein each said light source has the power output of independent variable, and said light source conditioned is so that optionally change their independently power outputs.

11. imaging system according to claim 11, wherein said light source are programmable laser diodes, it can come to regulate separately through changing the electric current of supplying with said diode.

12. imaging system according to claim 12, wherein said light source is arranged with linear array.

13. imaging system according to claim 10, wherein said afocal optical repeater comprise a series of power supply speculums that form afocal system.

14. imaging system according to claim 10, wherein said light source is a laser instrument.

15. imaging system according to claim 15, wherein said power supply speculum comprises first concave mirror, second convex reflecting mirror and the 3rd concave mirror.

16. according to the said imaging system of claim 10; The center to center that wherein said light source is compared between the said lens has the structure of point-like substantially at interval; Consequent said first image amplifies through said optical repeater, so that said second image comes overlapping by selected amount.

17. imaging system according to claim 1, wherein said light source is a laser instrument.

18. an imaging system, it comprises:

The LASER Light Source array, said LASER Light Source array produces the array of laser beam separately;

Lens arra, it is corresponding to said LASER Light Source array, and is arranged in the select location with respect to said LASER Light Source array, so that produce the magnified image of said laser beam separately; And

The afocal optical repeater, it is arranged in the select location with respect to said lens arra, so that produce the image of said laser beam separately at image plane, wherein said image satisfies selected fuzzy criterion.

19. imaging system according to claim 19, each inner lens of wherein said lens arra have a front focal plane and a back focal plane, and wherein said laser is arranged in the selected object plane with respect to the said front focal plane of said lens separately.

20. imaging system according to claim 20; Wherein each laser beam has with a tight waist; And wherein said optical repeater has an object plane being positioned at respect to said a distance with a tight waist, so that the contiguous image that is formed by said optical repeater comes overlapping by selected amount.

21. imaging system according to claim 19; Wherein each laser beam has with a tight waist; And wherein said optical repeater has an object plane being positioned at respect to said a distance with a tight waist, so that the contiguous image that is formed by said optical repeater comes overlapping by selected amount.

22. imaging system according to claim 22, wherein said optical repeater is an afocal system, and wherein concerning an object that is positioned at said object plane, the aberration in the said image is able to minimize.

23. imaging system according to claim 23, wherein said laser are the multi-mode laser devices.

24. imaging system according to claim 22, wherein each said laser has the power output of independent variable, and said laser conditioned is so that optionally change their independently power outputs.

25. imaging system according to claim 25, wherein said laser are programmable laser diodes, it can come to regulate separately through changing the electric current of supplying with said diode.

26. a system that is used on light sensitive tag, writing record information, it comprises:

Array of source, it produces beam array;

Lens arra, it is used for said beam direction image plane corresponding to said light source;

Labelling apparatus, it is used for said light sensitive tag is positioned said image plane;

The afocal optical repeater, it is arranged between said array of source and the said labelling apparatus, on said light sensitive tag, produces the magnified image of said light beam, thereby so that makes said label exposure and on said label, write the record pattern.

27. system according to claim 27; The said device that wherein is used to locate light sensitive tag comprises the bellows with bellows top, and said bellows remains on the appropriate location through making interface between said bellows top and the said label keep low pressure with said label.

28. system according to claim 28; Wherein said bellows is fixed on the rotatable support; It obtains label in primary importance, and rotates to second axial location along the optical axis of said optical repeater, so that make said label be exposed to said beam array.

29. system according to claim 29, wherein said bellows is further adapted for and rotates to the 3rd position and circumferentially extending, so that said label is applied on the article.

30. system according to claim 29; Wherein said image has depth of focus; The said axial location of said label has known variable quantity, and the said depth of focus of said image is chosen to be at least the same big with the said variable quantity of the said axial location of said label.

31. system according to claim 27, wherein said optical repeater has optical axis, and the said device that is used to locate said label is suitable for making said label when being exposed to said light beam, to move through said optical axis.

32. system according to claim 31; Wherein said light beam is along the first axle property aligning perpendicular to said optical axis, and said labelling apparatus make said label when being exposed to said light beam along moving through said optical axis perpendicular to said first with said optical axis second.

33. it is bar code that system according to claim 33, wherein said light source conditioned write the said pattern of record on said label with the said label of box lunch during through said optical axis.

34. system according to claim 27, wherein said light source be can optical maser wavelength the diode laser of operation, and said label has three-decker, wherein to be included under the said optical maser wavelength be translucent material to bottom; The intermediate layer absorbs the light under the said optical maser wavelength and transform light energy is become heat; And when the illumination that the front side layer layer of thermal sensitivity is crossed said trnaslucent materials in said intermediate layer by transmission is penetrated, the heat that response is produced by said intermediate layer and change the color of crossing the position of said trnaslucent materials in transmission.

35. system according to claim 27; Wherein said light beam is a laser beam; Each laser beam has with a tight waistly with respect to said lens arra a distance, and said optical repeater is to be placed on to be convenient to adjacent beams image with a tight waist and to come position overlapped by selected amount.

36. system according to claim 27, the magnifying power of wherein said magnified image is a mark.

37. a system that is used on light sensitive tag, writing record information, it comprises:

Array of source, it produces beam array;

Lens arra, it is used for said beam direction image plane corresponding to said light source;

Labelling apparatus, it is used for said light sensitive tag is positioned said image plane;

Optical repeater; It comprises at least one power supply reflecting surface; Have the optical axis parallel substantially with the said optical axis of said lens; And be arranged between said source array and the said labelling apparatus, thereby so that on said light sensitive tag, produce the magnified image of said light beam and write the record pattern at said label.

38. according to the described system of claim 38; The said device that wherein is used to locate light sensitive tag comprises the bellows with bellows top, and said bellows remains on the appropriate location through making interface between said bellows top and the said label keep low pressure with said label.

39. according to the described system of claim 39; Wherein said bellows is installed on the rotatable support; It obtains label in primary importance, and rotates to second axial location along the optical axis of said optical repeater, so that make said label be exposed to said beam array.

40. according to the described system of claim 40, wherein said bellows is further adapted for and rotates to the 3rd position and circumferentially extending, so that said label is applied on the article.

41. according to the described system of claim 38; Wherein said light beam is along the first axle property aligning perpendicular to said optical axis, and said labelling apparatus make said label when being exposed to said light beam along moving through said optical axis perpendicular to said first with said optical axis second.

42. according to the described system of claim 38, it is bar code that wherein said light source conditioned is write the pattern of record on said label with the said label of box lunch during through said optical axis.

43. according to the described system of claim 38, wherein said light source be can optical maser wavelength the diode laser of operation, and said label has three-decker, wherein to be included under the said optical maser wavelength be translucent material to bottom; The intermediate layer absorbs the light under the said optical maser wavelength and transform light energy is become heat; And when the illumination that the front side layer layer of thermal sensitivity is crossed said trnaslucent materials in said intermediate layer by transmission is penetrated, the heat that response is produced by said intermediate layer and change the color of crossing the position of said trnaslucent materials in transmission.

44. according to the described imaging system of claim 38, wherein said light source is a laser beam.

45. a method for imaging, it comprises:

A plurality of light sources are provided;

Calibration is from the light of said light source, so that produce corresponding a plurality of collimated light beams; And

On image plane, produce the image of said a plurality of light beams with the afocal mode, each image has the depth of focus and minimum spot definition of regulation.

46. according to the described method of claim 46, wherein said light source has the structure of point-like substantially, and makes consequent said collimated light beam on said image plane, come overlapping by selected amount.

47. according to the described method of claim 47, it further comprises makes said image amplify the amount of fraction.

48. according to the described method of claim 46, it further comprises regulates said light source so that optionally change their other power output.

49. according to the described method of claim 47; It further comprises with linear array arranges said light source; So that produce two-dimensional pattern through regulating said light source, objective body moves through said light beam on said direction perpendicular to said linear array simultaneously.

50. a method for imaging, it comprises:

A plurality of light sources are provided;

Calibration is from the light of said light source, so that produce corresponding a plurality of collimated light beams; And

On image plane, produce the image of said a plurality of light beams with the reflection mode.

51., wherein produce image and comprise said a plurality of light beam is reflected from a plurality of power supplies surface continuously with the reflection mode according to the described method of claim 51.

52. according to the described method of claim 52, it further comprises the said image of amplification.

53. according to the described method of claim 51, it further comprises regulates said light source, so that optionally change their other power output.

54. according to the described method of claim 52; It further comprises with linear array arranges said light source; So that produce two-dimensional pattern through regulating said light source, objective body moves through said light beam on said direction perpendicular to said linear array simultaneously.

55. according to the described method of claim 51, wherein said light source is a LASER Light Source.

56. a method for imaging, it comprises:

Provide and have a plurality of LASER Light Sources of output separately;

Produce a plurality of images separately of said output independently at select location; And

On image plane, produce the single image of said output with the afocal mode, wherein selected fuzzy criterion is satisfied in the said a plurality of outputs on said image plane.

57. a method of on light sensitive tag, writing record information, it comprises:

Said light sensitive tag is placed on select location;

Array of source is provided;

Produce a plurality of light beams separately from said light source; And

Said a plurality of light beams separately are imaged on the said label with the afocal mode, thereby so that the record pattern are also write in said label exposure on said label.

58. a method of on light sensitive tag, writing record information, it comprises:

Said light sensitive tag is placed on select location;

Array of source is provided;

Produce a plurality of light beams separately from said light source; And

Said a plurality of light beams separately are imaged on the said label with the reflection mode, thereby so that said label exposure are also write the record pattern at said label.

Images