Background technology
The English of contact-type image sensor is Contact Image Sensor (being abbreviated as CIS).It is a kind of light signal to be converted into the transducer of the signal of telecommunication, is widely used in fields such as diagram form scanner, facsimile machine, landmark identification device and business automation equipment.
Shown in accompanying drawing 3, the CIS transducer mainly is made up of light source, lens pillar, glass, shell, photo-electric conversion element and photosensitive circuit.
The light that light source sends sees through glass and reaches (file, image etc.) on the object that is scanned; Along with the difference of the bright-dark degree of scanned object, light is partly or entirely reflexed on the lens pillar, and light is after lens focus; Shine on the photo-electric conversion element imaging array of photosensitive circuit plate; Imaging array is made up of several light-sensitive elements, and the different optical signals light-sensitive element of bright-dark degree is transformed into the signal of telecommunication that voltage magnitude varies in size, and through shift register signal is delivered to operational amplifier then; Signal is sent to connector after amplifying, can obtain the facsimile signal after opto-electronic conversion through connector.
The imaging array of existing C IS transducer is that linear pattern is arranged, the also linearly type arrangement of set of lenses of correspondence with it; Comprise a plurality of photo-sensitive cells in each photo-electric conversion element of formation imaging array, these photo-sensitive cells also are that linear pattern is arranged.Therefore the CIS transducer view data of once gathering a line.
Chinese patent CN201830342 " image-scanning device that has the velocity compensation unit " wherein discloses the image-scanning device that the distortion of scanning process is compensated through writing scan speed.And in the prior art, when adopting contact-type image sensor scanning, contact-type image sensor itself can not directly be detected scanning motion, adopts supplementary means to guarantee the kinematic accuracy of scanning sample usually.For flat bed scanner, the common stepping accuracy assurance sampling precision that passes through to improve mechanical driving passes through to link to measure scanning motion speed at scanning plane installation roller and with velometer for hand-held scanner.Above method, the tolerance of the amplitude that scanning motion process medium velocity is changed is all lower.And imageing sensor can only be done rectilinear motion scanning, and for hand-held scanner, such restriction has reduced the convenient performance of scanner.
Summary of the invention
The object of the invention then is the deficiency to above-mentioned prior art; Through using a plurality of scanning arrays; Employing subscan array obtains the scanning motion data and merges output with view data in main scanning array scanning original copy; Through subscan the view data that main scanning obtains is carried out velocity compensation, guarantee the quality of image.
The object of the invention can be realized through following measure: in imageing sensor, comprise main scanning array 1, be used for subscan array 2 and computing module that location scanning moves.Main scanning array 1 is used for scan manuscript, subscan array 2 is used for the location scanning motion.
Subscan array 2 is positioned at around the main scanning array 1, writing scan motion characteristics image data.Main scanning photo-electric conversion element 4 in the main scanning array 1 is integrated in the same printed circuit board (PCB) with the subscan photo-electric conversion element 6 in the subscan array 2, synchronously outputting data signals.
Computing module can adopt single-chip microcomputer; The image that have scanning motion velocity characteristic captured according to subscan; Computing module at first calculates scanning motion change in location parameter curve, and then through this parameter curve the main scanning data splicing is combined into complete image.
Beneficial effect of the present invention is:
Through adopting a plurality of imaging arrays, make contact-type image sensor possess the ability of detecting scanning motion, need be by other mechanisms or parts, can accomplish splicing and combining of image voluntarily.Because main scanning array and subscan array package are one, precision is high, high conformity, more can adapt to the applied environment and the application demand of various scannings.
Description of drawings
Fig. 1 is existing contact-type image sensor schematic diagram.
Fig. 2 is the photo-electric conversion element chip structure figure in the existing contact-type image sensor.
Fig. 3 is existing contact-type image sensor structure chart.
Fig. 4 is a rectangular photo-electric conversion element chip sketch map of the present invention.
Fig. 5 is the contact-type image sensor structure chart that has linear subscan array of the present invention.
Fig. 6 is the contact-type image sensor structure chart that has rectangular subscan array of the present invention.
Among the figure: 1, main scanning array; 2, subscan array; DOC, original copy to be scanned;
3, main scanning set of lenses; 4, main scanning photo-electric conversion element; 7, photo-sensitive cell;
5, subscan set of lenses; 6, subscan photo-electric conversion element; 8, printed circuit board (PCB).
Embodiment
Rely on the basic general knowledge of this area below, the present invention done explanation further in conjunction with accompanying drawing:
Shown in accompanying drawing 1, between the imaging array (i.e. one group of photo-electric conversion element) of original copy and contact-type image sensor, one group of lens is arranged, corresponding a pair of lens directly over each photo-electric conversion element focus on original copy to be incident upon on the photo-electric conversion element and form images.
Shown in accompanying drawing 2, comprise one group of linearly photo-sensitive cell of type arrangement in the photo-electric conversion element.Photo-electric conversion element chip total length in the legend is 8080 μ m, wherein comprises 96 photo-sensitive cells, and photo-sensitive cell is arranged in a linear, spacing is 84 μ m.
In fact the precision of subscan is exactly the motion positions precision of scanning, and for obtaining stay-in-grade image, the motion positions precision grade of scanning generally will be higher than the precision grade of scan image.For example, when the main scanning precision was 300DPI, the motion positions precision can be set at 600DPI or higher.Of the present inventionly focus on having increased subscan array 2, the displacement variable that produces when its role is to follow the trail of scanning motion.Therefore, subscan array 2 need design by higher resolution standard.But the total amount of the image data of subscan is lower, so can not exert an influence to scanning process.Be the displacement variable that makes that subscan array 2 produces when being more suitable for following the trail of scanning motion, its design and structure and main scanning array 1 have certain difference.
Contact-type image sensor adopts the LED Light-Emitting Diode as light source usually, and the light source that contact-type image sensor sends when obtaining coloured image once directly light shines on the original copy.Three kinds of color LEDs (red, green, blue) scan needed three primary colors through switching luminous providing fast.
At this moment, main scanning array 1 has carried out three samplings when obtaining each hardwood view data, then need not switch with subscan array 2 corresponding light sources, and subscan array 2 is with gray scale sampling configuration image data.That is, under color mode, the sample frequency of subscan is actually three times of main scanning sample frequency.Such design can further improve the positioning accuracy of subscan array 2.
Because main scanning array 1 and subscan array 2 possibly adopt the light source of different optical effect; Therefore can be between main scanning array 1 and subscan array 2; Lighttight baffle plate is set the light path of two arrays is separated, form relatively independent light path, to reach optical effect preferably.
Embodiment 1:
The structure of employing shown in accompanying drawing 5, two subscan arrays 2 are arranged at the both sides of main scanning array 1 respectively.The linear that is arranged as of the subscan photo-electric conversion element 6 in the subscan array 2 is arranged; The installation direction of subscan array 2 and main scanning array 1 form 90 degree angles; Wherein the installation direction of subscan photo-electric conversion element 6 also forms 90 degree angles with main scanning photo-electric conversion element 4; Corresponding a pair of lens directly over each subscan photo-electric conversion element 6 are with the original copy focal imaging.
In scanning process, main scanning array 1 is done the rectilinear motion scan manuscript along the Y direction, and 2 of subscan arrays are gathered Y scanning direction moving displacement amount simultaneously.
For obtaining high orientation precision, when main scanning resolution is 300DPI, be 600DPI with the subscan resolution setting.Can adopt photo-sensitive cell to arrange the precision that photo-electric conversion element chip more closely can reach 600DPI: chip length overall 8080 μ m, photo-sensitive cell spacing 42 μ m comprise 192 photo-sensitive cells.
Set of lenses in the contact-type image sensor adopts the technology of similar echelon lens sometimes.Echelon lens is meant the lens of " ladder " shape noncontinuous surface, is made up of a series of concentric ring-shaped zones, claims zone lens again, reaches the focal length weak point and the big optical imagery effect of diameter.The echelon lens that adopts optical plastic to make, endless belt width can minimum can be less than 1 millimeter, each endless belt all is the part of taper seat, the cone-apex angle of different endless belt is different; Very narrow because of endless belt, the curved surface of taper seat and theory demand does not almost have difference, so do not influence optical property.
When main scanning set of lenses 3 was the echelon lens group, the design of subscan set of lenses 5 also cooperated with main scanning set of lenses 3, reached coherent optical property and imaging effect.
The advantage of this embodiment is simple in structure, and shortcoming is to be applicable to that the movement position of following the trail of on the rectilinear direction changes, and is adapted at having in the scanning device of rectilinear motion track using (like flat bed scanner).
Embodiment 2:
The structure of employing shown in accompanying drawing 6, two subscan arrays 2 are arranged at the both sides of main scanning array 1 respectively.Being arranged as rectangular arranged and (also can being arranged in other shapes of subscan photo-electric conversion element 6 in the subscan array 2 according to actual conditions; Like circular or irregular shape etc.); Wherein the photo-sensitive cell in the subscan photo-electric conversion element 67 is by rectangular arranged; Corresponding a pair of lens directly over each subscan photo-electric conversion element 6 are with the original copy focal imaging.
Scanner moves freely in the plane of scanning motion, and in scanning process, main scanning array 1 is done the plane motion scan manuscript, 2 whiles of subscan array acquisition plane scanning motion displacement.
The positioning accuracy that the detecting plane motion needs is higher, when main scanning resolution is 300DPI, should be 600DPI or 1200DPI with the subscan resolution setting therefore.At this moment, not only can select for use photo-sensitive cell to arrange subscan photo-electric conversion element 6 more closely, can improve the optical magnification of subscan set of lenses 5 simultaneously.For example, when the optical magnification of main scanning set of lenses 3 was 0.5 times, the optical magnification of subscan set of lenses 5 was set at 1 times or 1.5 times or the like.
The advantage of this embodiment be can comprehensive tracking scanning motion change in location, be applicable to that portable scanning uses, especially manually promote the application that scanner scans, like the hand-held scanner pen etc.The application that also goes for curved surface scanning of this embodiment.
Above embodiment is not to concrete restriction of the present invention, is not breaking away from claims restricted portion of the present invention, can make all concrete modifications to this device.