A kind of composite diffraction space code and making thereof and detection method
The present invention relates to a kind of sign and making and detection method that is used for taxonomy of goods and information indicating, be specifically related to a kind of identification and false proof composite diffraction space code and making and detection method automatically of being easy to.
Along with development of computer, the computer nowadays information management is deep into the institutional framework field from the low-level affairs of handling daily routine, further performance is controlled and coordination function, handle the occasion of mass data at needs, usually need article are classified and information indicating, as in the commodity circulation links commodity being classified, at credit card, I.D., be provided with on the article such as securities and be convenient to the information flag that computing machine directly detects, in the library, books are classified and mark etc., these marks require to be convenient to use Computer Automatic Recognition, to satisfy fast, accurately, the requirement of a large amount of amount of input informations is convenient to bring into play the function of computing machine.
At present, the automatic identification technology that is used for taxonomy of goods and information indicating mainly contains magnetic stripe, IC-card, radio-frequency technique, bar code etc., though wherein magnetic stripe, IC-card have the read-write advantage of data, but the cost that it identifies one by one to article is than higher, be applicable to card class article such as credit card, and should not be used for the mark one by one of article such as shiploads of merchandise, books, radio-frequency technique portability mass data and be contactless identification, but its cost is quite high, only be applicable to the occasion of using repeatedly, be not suitable for the occasion of disposable sign; Bar code is with respect to aforementioned several technology, has high input speed, the reliability height, cost is low, to advantage such as environment for use is not harsh, adopt mode of printing to make simultaneously, easy to use, thereby become the data input technology of widespread use in modern production and management domain at present, it is by one group of regularly arranged bar and the empty mark of forming, constitute bar by the dark bars symbol of printing, clear area between two bars accord with is represented empty, bar, empty is wide, specific arrangement narrow and relative position at interval has just constituted information, this by bar, the empty digital coding of forming can be distinguished for machine, and be easy to be translated into binary number and decimal number, be easy to connect and compose bar code system with computing machine, but also there is certain shortcoming in bar code system, mainly be that its information density is low, information capacity is little, be mainly used in the sign of article and can not be used for article are described, can only play effect to the taxonomy of goods retrieval, though the 2D bar code technology of development is increasing aspect information density and the capacity recently, still be difficult to satisfy people's requirement, simultaneously, because its information density is low, need finish sign with bigger area to article, such as the EAN bar code that is most commonly used to the commodity classification sign at present 13 bit digital are arranged, its standard contour dimension is 37.92 millimeters * 26.26 millimeters, during actual the use certain zoom ranges can be arranged, but generally between standard-sized 0.8 times to 1.2 times, taken in the commodity packaging than large tracts of land, influenced the appearance design of commodity.
The object of the invention provides a kind of information density big, take up room little and lower-cost composite diffraction space code and detection method thereof, is used for the classification and the sign of large numbers of items.
For achieving the above object, the present inventor invents according to following principle and design philosophy: bar codes technique is a very ripe automatic identification technology at present, coding scheme wherein is quite perfect, it adopts the notion of binary number, the information that prints out is changed into can be for the machine language of machine recognition, in this process, the strong and weak different light that photoelectric conversion device reflects bar code is converted to the different level of height and is distinguished by machine, therefore, the means that can consider a kind of optics replace the original common printed art of using, to obtain a kind of existing barcode encoding system of utilizing, increased substantially the classification and the information expression method of information density simultaneously.When light beam during by a grating (perhaps reflecting) from a grating, can obtain certain diffraction pattern, and the development of holographic technique at present makes the making holographic grating become a kind of technology of practicality, particularly on the aluminium film, can make reflection holography grating (being similar to the making of holographic false proof icon) at low cost, and the area of this grating can be done very for a short time, and practical scope can be at 0.02 * 0.02mm
2-0.08 * 0.08mm
2, thereby can consider with the reflected light in the diffraction light replacement bar code, in the spatial reproduction bar code information.
Obtained the technical solution used in the present invention thus: a kind of composite diffraction space code, it comprises the pel array of being made up of pixel, be provided with a little grating in described each pixel, each little grating has specific grating corner and spatial frequency, makes that its first-order diffraction luminous point is arranged by preset rule after laser radiation.
In the technique scheme, described " first-order diffraction luminous point " is meant the first-order diffraction luminous point of the plus or minus that little grating produces after laser radiation, described first-order diffraction luminous point is by certain regularly arranged, be used for expression information, wherein a kind of preferably queueing discipline can adopt Barcode Rules, the diffraction luminous point is represented the sky in the bar code, and the bar in the bar code is represented in the dead zone between the diffraction luminous point; In this programme, with the diffraction luminous point and represent at interval sky and bar in the bar code, can quote existing various barcode encoding rule easily, finish the function of classification and information representation, simultaneously, coded message represents that by the first-order diffraction luminous point that little grating produces the area of little grating own is minimum, and can line up array, improve information density greatly.
In such scheme, variation according to little grating spatial frequency and corner, can be divided into several situations: the one, the spatial frequency of each little grating is identical, only change the grating corner, its first-order diffraction luminous point constitutes arc, and described rule adopts the coding rule of one-dimensional bar code, and this method is not owing to need change the spatial frequency of little grating, it is more convenient to calculate the grating corner, but it is bigger to relate to area when detecting; The 2nd, if the spatial frequency of each little grating is all different with the grating corner, make its first-order diffraction luminous point constitute straight line, described rule adopts the coding rule of one-dimensional bar code, then more convenient detection; Can also include the pel array more than 2, the first-order diffraction luminous point group that each pel array constitutes laterally or vertically arranges in the space, thereby expresses more information; Wherein the first-order diffraction luminous point group of each pel array formation vertically arranges in the space, can constitute the composite diffraction space code that meets the two-dimensional bar code coding rule.
In the technique scheme, according to the variation of little grating spatial frequency and corner, can also play encryption, anti-fake effect, its method is that the queueing discipline of the first-order diffraction luminous point of described little grating array is to be arranged in specific letter, numeral or figure.
In the technique scheme, practical and cheaply a kind of scheme be: the little grating in the described pel array is a reflection-type diffraction grating, and described pel array is printed on the metallic film, and is similar with the method for making of existing holographic false proof sign; Certainly, also can adopt the transmission diffraction grating, but its cost of manufacture is higher relatively, and range of application is narrower.
The method for making of composite diffraction space code of the present invention, the queueing discipline of selected grating first-order diffraction luminous point, calculate the spatial frequency and the grating corner of each little grating according to the optics formula, make its diffraction light point meet described queueing discipline, and the centre distance between luminous point is not less than the size of Airy disk, utilize the laser hologram technique etching to meet the grating pel array of above-mentioned spatial frequency and corner requirement, and be transferred to metallic film and get on.
In actual fabrication, can prepare a computer program according to optical principle, calculate the spatial frequency and the grating corner of grating, thereby when encoding for given one, utilize computing machine to generate the relevant data of corresponding grating pel array automatically, and can be connected with laser system, reach the effect of automatic shooting grating array.
The detection method of composite diffraction space code of the present invention, by laser beam emitting device, collimation lens, imaging len, optical detector and treatment circuit constitute the testing circuit of composite diffraction space code with computer system, the laser that laser beam emitting device sends becomes collimated light behind collimation lens, be radiated on the composite diffraction space code at a certain angle, reflected light is through imaging len, the diffraction luminous point is imaged on the focal plane of lens, the test surface of optical detector is in the position of focal plane, thereby record the diffraction light lattice array, send into computing machine behind the treated circuit and handle, obtain the coded data of composite diffraction space code.Optical detector wherein can be used CCD, and this moment, optical detector should be done relative motion with composite diffraction space code, obtained data with serial mode; Also can use SSPD array, CCD face battle array etc., at this moment, can once obtain the diffraction light of whole composite diffraction space code, thereby obtain data with parallel mode.
Because the technique scheme utilization, the present invention compared with prior art has following advantage:
1, because the present invention adopts the space diffracting light expressing information, the area of its each holographic little grating is at 0.02 * 0.02mm
2-0.08 * 0.08mm
2Between, with the EAN sign indicating number in the one-dimensional bar code is example, its code has 13 bit digital, contour dimension is 37.92mm * 26.26mm, the bar code size of code that is comprised in the unit length be 3.43 characters/centimetre, and use composite diffraction space code of the present invention, can express same information with 64 left and right sides pixels, be 8 * 8 pel array, the size of a grating pixel is in 0.08mm * 0.08mm, and the area of an array is 0.0041cm
2, the size of code that comprises in the unit area is 3.17 * 10
3Character/square centimeter, thereby information capacity of the present invention can improve 2 to 3 orders of magnitude, corresponding, represent identical information, its area occupied is much smaller than bar code;
2, unrecognizable little grating is formed because the present invention is naked eyes, can also form specific letter, numeral or graphics combine by the position of control diffraction luminous point simultaneously, thereby can form the verification figure of characteristics with one part of pixel, very strong anti-counterfeiting performance is arranged;
3, the present invention can make of existing holographic false proof film, and cost is low, is specially adapted to the information representation of the article in enormous quantities of every sign of need;
4, because the present invention has improved information density greatly, except the class mark effect that can replace former bar code, can also be used as information indicating, can break away from database in some occasion and use.
Accompanying drawing 1 is with the pel array of bar code rule encoding and the diffraction luminous point synoptic diagram of reproduction in the embodiment of the invention one;
Accompanying drawing 2 is the grating synoptic diagram in the pel array among Fig. 1;
Accompanying drawing 3 is the pel array in the embodiment of the invention two and the diffraction luminous point synoptic diagram of reproduction;
Accompanying drawing 4 is the pel array in the embodiment of the invention three and the diffraction luminous point synoptic diagram of reproduction.
Wherein: [1], pel array; [2], diffraction luminous point; [3], pixel; [4], little grating.
Below in conjunction with drawings and Examples the present invention is further described:
Embodiment one: referring to attached illustrated in figures 1 and 2, a kind of composite diffraction space code, it comprises the pel array of being made up of pixel 1, be provided with a little grating 4 in described each pixel 3, each little grating 4 has specific grating corner and spatial frequency, make regularly arranged by one-dimensional bar code of after laser radiation its first-order diffraction luminous point 2, wherein diffraction luminous point 2 is represented the sky in the bar code, and the bar in the bar code is represented in the dead zone that the diffraction luminous point is 2; Selecting of the spatial frequency of each little grating 4 and grating corner makes its first-order diffraction luminous point 2 constitute straight lines; Little grating 4 in the wherein said pel array 1 is a reflection-type diffraction grating, is produced on the aluminium film.
The pel array of present embodiment also can be made of a plurality of little arrays, and the first-order diffraction luminous point 2 that each little array produces is positioned at identical position, thereby has strengthened the intensity of diffraction luminous point 2, is convenient to detect and guarantee the correctness of testing result.
When making the composite diffraction space code of present embodiment, at first determine the coding rule of bar code, can select the EAN bar code for use for general merchandise, for guaranteeing that little grating 4 first-order diffraction luminous points 2 are arranged as straight line, the spatial frequency of each little grating 4 and grating corner binomial parameter all will change, given reproduction light wave, can calculate the value of above-mentioned binomial parameter according to the optics formula, it should be noted that wherein the distance that makes in the first-order diffraction luminous point 2 in the heart is not less than the size of Airy disk, utilize the laser hologram technique etching to meet the grating pel array 1 of above-mentioned spatial frequency and corner requirement, select the self-adhesive paper or the plastics that are coated with the aluminium film for use, above-mentioned pel array 1 is transferred on the aluminium film, promptly obtains required composite diffraction space code.
Also can utilize digital laser hologram photo-composing system to finish the making of the composite diffraction space code of present embodiment, the bar code coding of the required reproduction of input in computing machine, finish the data computing of each little grating 4 in the pel array 1 by software, then according to result calculated control light path, automatically finish the etching of pel array 1, the dry plate that utilizes etching to obtain again is mother matrix, finishes transfer printing process.
The detection method of the composite diffraction space code of present embodiment: by laser beam emitting device, collimation lens, imaging len, optical detector and treatment circuit constitute the testing circuit of composite diffraction space code with computer system, the laser that laser beam emitting device sends becomes collimated light behind collimation lens, be radiated on the composite diffraction space code at a certain angle, reflected light is through imaging len, diffraction luminous point 2 is imaged on the focal plane of lens, the test surface of optical detector is in the position of focal plane, thereby record the diffraction light lattice array, send into computing machine behind the treated circuit and handle, obtain the coded data of composite diffraction space code.
The detecting device of present embodiment also can be made the card slot type detecting device, and laser beam angle is fixed, and the card card that is provided with composite diffraction space code moves in groove, employing CCD is a detector, and its photosurface is positioned on the focal plane of lens, can obtain coded data, at this moment, its detection data are serials.
Embodiment two: shown in accompanying drawing 3, a kind of composite diffraction space code, it comprises the pel array of being made up of pixel 1, be provided with a little grating 4 in described each pixel 3, each little grating 4 has specific grating corner and spatial frequency, make regularly arranged by two-dimensional bar of after laser radiation its first-order diffraction luminous point 2, wherein diffraction luminous point 2 is represented the sky in the bar code, and the bar in the bar code is represented in the dead zone that the diffraction luminous point is 2; Little grating 4 in the wherein said pel array 1 is a reflection-type diffraction grating, is produced on the aluminium film.
Present embodiment can obtain bigger information storage, can be used for information indicating, when making the composite diffraction space code of present embodiment, at first determine the coding rule of two-dimensional bar code, make the first-order diffraction luminous point form the arrangement of two dimension, the spatial frequency of each little grating and grating corner binomial parameter all will change, given reproduction light wave, can calculate the value of above-mentioned binomial parameter according to the optics formula, it should be noted that wherein the distance that makes between the first-order diffraction optical spot centre is not less than the size of Airy disk, utilize the laser hologram technique etching to meet the grating pel array of above-mentioned spatial frequency and corner requirement, select the self-adhesive paper or the plastics that are coated with the aluminium film for use, above-mentioned pel array is transferred on the aluminium film, promptly obtains required composite diffraction space code.
The detection method of the composite diffraction space code of present embodiment: by laser beam emitting device, collimation lens, imaging len optical detector and treatment circuit constitute the testing circuit of composite diffraction space code with computer system, the laser that laser beam emitting device sends becomes collimated light behind collimation lens, be radiated on the composite diffraction space code at a certain angle, reflected light is through imaging len, the diffraction luminous point is imaged on the focal plane of lens, the test surface of optical detector is in the position of focal plane, thereby record the diffraction light lattice array, send into computing machine behind the treated circuit and handle, obtain the coded data of composite diffraction space code.
Embodiment three: shown in accompanying drawing 4, a kind of composite diffraction space code, it comprises the pel array of being made up of pixel 31, be provided with a little grating 4 in described each pixel 3, each little grating 4 has identical spatial frequency, only changes their grating corner, makes regularly arranged by one-dimensional bar code on a camber line of its first-order diffraction luminous point 2 after the laser radiation, wherein diffraction luminous point 2 is represented the sky in the bar code, and the bar in the bar code is represented in the dead zone that the diffraction luminous point is 2; Little grating 4 in the wherein said pel array 1 is a reflection-type diffraction grating, is produced on the aluminium film.
Present embodiment is not owing to change the spatial frequency of little grating, it is comparatively convenient to calculate during making, when making the composite diffraction space code of present embodiment, at first according to relevant optics formula, determine the spatial frequency of little grating, again according to the coding rule of the bar code selected for use, calculate the grating corner of each little grating, it should be noted that wherein the distance that makes between the first-order diffraction optical spot centre is not less than the size of Airy disk, utilize the laser hologram technique etching to meet the grating pel array of above-mentioned spatial frequency and corner requirement, select the self-adhesive paper or the plastics that are coated with the aluminium film for use, above-mentioned pel array is transferred on the aluminium film, promptly obtain required composite diffraction space code.
The detection method of present embodiment and aforementioned two embodiment are roughly the same, but because the diffraction luminous point that reproduces is along arc shooting, detect relative complex, the one, move along arcuate directions after can selecting ccd detector for use, but control is complicated, the opposing party's rule is to select for use than the detector of large photosensistive surface to survey, the corresponding detection cost that increased.