CN115086502A - Non-contact scanning device - Google Patents

Abstract

A non-contact scanning device at least comprises a machine table, a scanning component, a plurality of light capturing units and a plurality of scanning units, wherein the machine table at least comprises a platform structure used for placing a scanning object, the scanning component is transversely arranged above the platform structure along a second direction and used for acquiring images of the scanning object, the scanning component is configured to be capable of moving above the platform structure along a first direction so as to acquire the images of the scanning object, the scanning component comprises a plurality of light capturing units which are linearly arranged and used for acquiring at least one part of the images of the scanning object, and in the case that a viewpoint distance exists between adjacent light capturing units, the light capturing units are arranged in a mode that the viewpoint distance is gradually reduced from the center to the edge.

Description

Non-contact scanning device

Technical Field

The invention relates to the field of optical scanning devices, in particular to a non-contact scanning device.

Background

Scanners, in particular optical-based scanners, are used to acquire fine image information of at least one face of an object. In the field of document scanning applications, scanners are used to scan content, typically textual or pictorial information, on a paper document. The scanner has at least one imaging system for acquiring images of the scanned object, and the imaging system is generally selected from optical imaging devices, such as high-definition cameras, and the like. To obtain a high-definition image of the scanned object globally, the imaging system is usually configured to move relative to the surface of the scanned object to acquire a global scan field of view. On a flatbed scanner, the movement is accomplished on the imaging system, which typically involves moving the camera's rails and drive motors. On a sheet fed scanner, the above movement is achieved by controlling the movement of the scanning object itself, which may be used with a scrolling device. In most scanners, ambient light is generally excluded to minimize the imaging effect of the environment, the scanner is generally configured or deformable to be opaque, such as a cassette or cover, and the component that shines light on the paper to enable the camera to capture the reflection of the document is a light source component disposed inside the scanner.

CN101860648B discloses a large format scanner for scanning movement of a data carrier assembly and a scanning method thereof, which includes: the scanning unit comprises a rack, a scanning element group and a scanning data bracket assembly which are arranged on the rack and are composed of a plurality of surface type scanning units, and a computer host which controls the scanning action of the scanning element group and processes scanned pictures and texts; it is characterized in that each surface type scanning unit is arranged in a row, fixed on the frame and positioned above or below the scanning data bracket assembly; also comprises a scanning data bracket component horizontal moving mechanism connected with the scanning data bracket component. When scanning, the scanning data carrier component horizontal moving mechanism drives the scanning data carrier component to move to the lower part of the scanning component group, the scanning component group scans the corresponding scanned data one by one according to the regional sequence, and then the computer mainframe adopts the multi-channel and multi-thread technology to splice the scanned pictures and texts and restore the scanned data. The scanning device has the advantages of large scanning amplitude, high precision, small volume and production cost saving.

However, the scanning equipment related in the prior art has large volume, occupies more land, is inconvenient to install, has poor imaging definition and light interference resistance and has low scanning precision.

Furthermore, there are differences in one aspect due to the understanding of those skilled in the art; on the other hand, since the applicant has studied a great deal of literature and patents when making the present invention, but the disclosure is not limited thereto and the details and contents thereof are not listed in detail, it is by no means the present invention has these prior art features, but the present invention has all the features of the prior art, and the applicant reserves the right to increase the related prior art in the background.

Disclosure of Invention

In view of the foregoing, the present invention provides a non-contact scanning apparatus, which at least includes a stage at least including a platform structure for placing a scanning object, a scanning member disposed above the platform structure in a second direction and configured to acquire an image of the scanning object, the scanning member being configured to be movable above the platform structure in the first direction to acquire the image of the scanning object, the scanning member including a plurality of light capturing units arranged in a linear manner and configured to acquire at least a part of the image of the scanning object, wherein, in a case where a viewpoint distance exists between adjacent light capturing units, the light capturing units are arranged in a manner that the viewpoint distance gradually decreases from a center to an edge.

Preferably, the viewpoint distance is a pitch of adjacent light capturing structures, and the viewpoint distance of the light capturing structure near the center is configured to be greater than the viewpoint distance of the light capturing structure near the edge.

Preferably, in the case of an arrangement in which the light capturing units are tapered in accordance with the trend of the viewpoint distance from the center toward the edge, the overlapping regions of the fields of view of the adjacent light capturing units are varied in an increasing manner from the center toward the edge, so that the images of the scanning object captured by the scanning member, whose regions correctable against each other at the images at the edge positions are relatively more.

Preferably, the scanning member further comprises a plurality of light sources, the light sources being disposed in the scanning member in a manner that accompanies the light capturing units in a tapered arrangement from center to outside in a manner that at least the field of view of each light capturing unit can be illuminated.

Preferably, the area of the scanning object illuminated by the at least two light sources at the edge position in the second direction at the same time is larger than the illuminated area at the middle position, so that the edge of the scanning object is captured by the light capturing unit in a relatively well illuminated state.

Preferably, the scanning member is connected to the machine table through driving arms disposed at both ends, respectively, to form a state suspended above the platform structure.

Preferably, each light capturing unit is correspondingly provided with at least one driver configured to be able to adjust its own position in the third direction, and the focal length of each light capturing unit can be individually adjusted when the position is adjusted in the third direction.

Preferably, a driving structure is arranged in the machine table, and the driving structure comprises a driving track and driving arms, wherein the driving track is arranged on two sides of the machine table along the first direction, and one ends of at least two driving arms extending along the third direction are movably connected to the driving track, so that the moving direction of the driving arms is limited in the first direction of the driving track.

Preferably, at least two driving arms are connected by a cross bar, and the driving structure further comprises a driving assembly which is connected to the cross bar in a transmission manner to drive the driving arms to move along the first direction.

Preferably, a partial pressure assisting structure for assisting the flattening of the scanning object is disposed on the platform structure, and is configured to be capable of flattening the scanning object on the platform structure based on the negative pressure generated on the platform structure.

Drawings

FIG. 1 is a schematic diagram of the arrangement of a light capture unit according to a preferred embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a preferred embodiment of the apparatus provided by the present invention;

FIG. 3 is a schematic diagram of the internal structure of a scanning head according to a preferred embodiment of the present invention;

FIG. 4 is a schematic view of a preferred embodiment of the elevating structure of the driving arm according to the present invention;

in the figure: 100. a machine platform; 110. a platform structure; 200. a drive structure; 210. a drive rail; 220. a drive arm; 300. a scanning member; 310. a light capturing unit; 320. a driver; 400. a control unit.

Detailed Description

The following detailed description is made with reference to fig. 1 to 3.

The invention provides a non-contact type scanning device which is used for scanning paper articles. The apparatus is used to acquire an image of at least one surface of a scanned object. Preferably, the scanning object is a paper, and it is generally understood that the paper has at least two pages with a large area, and the pages can record information by physically attaching a label thereto. The marker can be ink, carbon powder, pen ink and the like; the information is the content conveyed by the specific arrangement of the markers, such as characters, pictures, tables and other information. The present apparatus is preferably used for scanning a fine image of a page portion of a sheet. The device adopts an optical imaging mode to acquire an image of a scanning object. Optical imaging is a process in which light rays emitted from an object or reflected to a certain direction after being irradiated are collected and restored to a digital image by a photosensitive element. Optical imaging generally has a photosensitive element, an optical member, a shutter, and the like. The light-sensitive element, such as a CMOS or CCD sensor commonly used in a camera, can convert light irradiated onto its optical sensor lattice into optical digital signals, and restore the optical digital signals at several positions of the lattice in the background according to the lattice positions to form image information. The optical member is a member for collecting and processing light to a path of the photosensitive element, and may be basically configured as a combination of a lens and a plane mirror, and the path of the light may be changed to achieve an effect of enlarging, reducing, or changing the depth of field of an image. The shutter component is used for controlling the light quantity entering the photosensitive element within a period of time, and when the shutter component is opened, the light can enter the photosensitive element.

In this embodiment, as shown in fig. 2, an apparatus capable of scanning large pages is provided, which at least includes a machine 100, an operating member and a scanning member 300, wherein the machine 100 is used to form a bottom support for supporting the whole apparatus and is used to support an object to be scanned, and therefore, the machine 100 has at least one position capable of flattening paper. Preferably, the platform structure 110 may be disposed on one of the planes of the machine 100 far from the ground or may be formed by such a plane, for example, when the machine 100 is configured as a substantially rectangular parallelepiped structure and is placed on the ground, one of the planes is generally opposite to and parallel to the ground, and the opposite side far from the ground may be disposed or formed as the platform structure 110.

Preferably, in order to provide an auxiliary flattening effect of the scan object placed on the platform structure 110, a wind pressure auxiliary structure is disposed below or around the platform structure 110, and is used for forcibly flattening the edge of the scan object by using the pressure caused by the flow of the supplied air. Because text recording tools such as paper often can produce phenomenons such as turn-up, fold, distortion in ageing process, consequently only rely on itself to be difficult to realize leveling and placing, this scheme has introduced wind pressure auxiliary structure, and it acts on platform structure 110 and can assist the paper to go on flattening. Specifically, the wind pressure auxiliary structure at least comprises a wind gap, and a channel or a directional flow direction for gas circulation is generated by the wind gap. The wind pressure auxiliary structure further includes a wind suction unit communicated with the wind gap through the wind suction pipe to realize directional flow of the air flow outside the wind gap along the direction inside the wind gap by applying negative pressure to the wind suction pipe and the wind gap, based on bernoulli's law, the air around at least one part of the scanned object is rapidly pumped away, the flow rate of the part of the air is accelerated, and simultaneously the fluid pressure is reduced, and the pressure of other parts will press the part of the scanned object on the platform structure 110. In one embodiment, the air ports are disposed on the panel of the platform structure 110, and may be disposed in a random or spaced sequence, and a mesh structure may be disposed between the air ports and the panel to increase the coverage area of the air suction surface, thereby forming an air flow direction substantially along the normal direction of the platform structure 110, in which case, the backside of the scanning object is directly "adsorbed" on the platform structure 110. In another embodiment, the air ports are disposed on the peripheral side of the platform structure 110, and may be a plurality of segments or connected air ports disposed along all edges of the platform structure 110, thereby constituting an air flow direction substantially parallel to the plane of the platform structure 110, in which case the edge portion of the scanning object is pressed against the platform structure 110 by the air pressure difference generated by the air flow. In other embodiments, both of the above two tuyere arrangement modes exist in the arrangement scheme. The air suction unit and the air suction pipeline can be arranged inside the machine table 100.

Therefore, the interior of the machine platform 100 may be or partially configured as a hollow structure, that is, a part of the accommodating space is provided, and at least a part of the remaining space, except the part of the space for accommodating the air suction unit and the air suction duct, may be used to store other objects, for example, a storage structure may be provided by providing a storage box or a drawer for storing paper, tools, and other objects.

Preferably, another embodiment is provided, in this embodiment, the combination of the air suction unit, the air suction channel and the air opening is set up in different zones, that is, the air pressure auxiliary structures are set up in multiple groups, which can be controlled to be opened or closed individually, and the air pressure auxiliary structures in the multiple groups can be configured to control the scan object auxiliary flattening conditions of different zones on the platform structure 110 respectively. For example, a first wind pressure auxiliary structure and a second wind pressure auxiliary structure are provided, wherein the first wind pressure auxiliary structure is disposed in one region of the platform structure 110, and correspondingly, the second wind pressure auxiliary structure is disposed in another complementary region of the platform structure 110, for example, the first wind pressure auxiliary structure is disposed in the upper half region of the platform structure 110, and the second wind pressure auxiliary structure is disposed in the lower half region of the platform structure 110.

Preferably, a power source is disposed in the machine 100, the power source may be a rechargeable battery or a transformer module capable of directly using external power to transmit electric energy, and the power source is at least electrically connected to the air suction unit to provide power for the air suction unit.

The machine table 100 is provided with a driving structure 200, which is capable of performing a relative position change motion with respect to the platform structure 110, wherein the driving structure 200 is capable of performing at least a parallel motion with respect to the platform structure 110. Specifically, the driving platform includes a driving rail 210 and a driving arm 220, at least one portion of the driving arm 220 is connected to the driving rail 210, and the driving rail 210 is used to define a moving direction of the driving arm 220. A driving assembly is further included to provide moving power to the driving arm 220, and specifically, a T-belt driven stepping motor synchronous driving mode may be adopted to provide Y-axis scanning motion power. Here, for convenience of description, the stage structure 110 is regarded as a reference object, and as shown in coordinate axes in the drawing, the stage structure 110 is configured to have a substantially rectangular surface structure, a direction indicated by the Y axis is a longitudinal direction of the stage structure 110, that is, an installation and movement direction of the driving rail 210 and the driving arm 220, and may be referred to as a second direction, and a direction indicated by the X axis is a width direction of the stage structure 110, and may be referred to as a first direction.

The driving arm 220 has at least two ends, one end of which is connected to the driving rail 210, and the other end of which extends upward along a direction substantially perpendicular to the ground, i.e. a Z-axis direction in the drawing, and at least exceeds a horizontal plane of the planar structure, and the Z-axis direction may be referred to as a third direction. The driving arms 220 are at least two, and the at least two driving arms 220 are respectively arranged near two sides of the planar structure arranged along the second direction; and preferably, the two driving arms 220 are symmetrically disposed about the central axis of the planar structure in the first direction. In some embodiments, the driving rail 210 may be provided as one, that is, the at least two driving arms 220 are connected to the one driving rail 210 and driven by the orientation of the driving rail 210 at the same time. In other embodiments, the driving tracks 210 are arranged in a manner that matches the number or arrangement positions of the driving arms 220, for example, one driving track 210 is arranged on each side of the platform structure 110 along the second direction, and the two driving tracks 210 are respectively used for driving a plurality of driving arms 220 arranged on each side.

In one embodiment, the driving arm 220 is slidably connected to the driving rail 210, and the driving rail 210 is correspondingly configured as an I-shaped rail. A cross bar connection is further provided between the at least two driving arms 220, the cross bars being arranged along a first direction and connected to the two driving arms 200 at both ends, respectively. The above-mentioned manner of "synchronous driving of the T-belt transmission stepping motor" is that the belt is connected to the cross bar, and the belt is driven by the transmission stepping motor to drive the cross bar to move along the second direction, so that the scanning member 300 connected to the driving arm 220 can move along the second direction to realize scanning. To ensure the driving accuracy, a travel detection assembly configured to be able to detect the driving accuracy of the stepping motor, i.e., the stepping accuracy, may also be provided. The apparatus may further include a control unit 400, wherein the control unit 400 at least has the capability of controlling the output parameter of the stepping motor based on the step precision data transmitted from the travel detection module and combining manual and/or programmed automatic regulation to control the travel precision of the scanning member 300.

The control unit 400 further has at least the following functions: the control part 400 is electrically connected to the wind pressure auxiliary structure, especially to the wind suction unit therein, to control at least the output parameters thereof, wherein the output parameters of the wind suction unit may include at least start-stop and output power, etc.; the control part 400 is electrically connected to the scanning member 300 to acquire the scanning data transmitted therefrom, and bidirectionally controls the operating parameters of the scanning member 300, which may include at least start-stop, definition selection, height of each light capturing unit 310 in the scanning member 300 in the third direction, and data transmission format, etc.

As shown in fig. 3, in the present embodiment, the scanning member 300 is configured to be a substantially strip-shaped configuration, and two ends of the scanning member can be respectively connected to the symmetrically arranged driving arms 220 in a manner of crossing over the platform structure 110 along the first direction, and the scanning member can be driven by the driving arms 220 to move along the first direction relative to the platform structure 110 and the scanning object placed thereon. At least one light capturing unit 310 is disposed in the scanning member 300, and preferably, a plurality of light capturing units 310 are disposed in sequence along the axial direction of the scanning member 300, wherein the axial direction is the same as the first direction in the installed state of the scanning member 300 shown in the figure.

The light capturing unit 310 is substantially similar to a photographing device such as a camera or a video camera, and functions to capture all or most of light within a predetermined viewing angle range thereof and convert the light into a digital image signal using a photosensitive element. In the present embodiment, the light capturing units 310 are set to a fixed focus property, the field of view range thereof is a fixed size when it does not itself produce a movement in a direction far from and near to the subject, and the field of view of each light capturing unit 310 should be set as small as possible in order to obtain a high-precision image, i.e., high-resolution image data, but this may cause one light capturing unit 310 to capture a high-definition image of only a part of the scanned subject during the movement relative to the scanned subject. For the high-definition images of at least one portion of the scanned object respectively acquired by the plurality of designed and used light capturing units 310, a common way of acquiring the complete image information of the scanned object is to combine the high-definition images of the portions acquired by the plurality of light capturing units 310 according to operations such as splicing, deduplication, optimization and the like of corresponding positions, and finally, a complete high-definition scanned image of the scanned object can be acquired. Here, in order to obtain consideration about the complete view angle of the scanned object and the cost of the camera, the conventional solution is to arrange the plurality of light capturing units 310 at equal intervals, each light capturing unit 310 is responsible for capturing the image content of one of the fields of view, and when the scanning member 300 itself is not moved, the sum of the fields of view of all the light capturing units 310 should at least include at least one physical range of the scanned object described by the side length. Preferably, when scanning starts, the initial position of the scanning member 300 should be set near one of the edges of the scanned object. This solution has certain convenience and simplicity, because it can bring certain advantages for the later image combination process by arranging several light capturing units 310 with the same parameters at equal intervals. The reason is that the captured images are relatively fixed in size, depth of field and position, and the area and vertical length of the overlapped part of the adjacent captured images are also relatively fixed. When the post-combination processing is carried out, the program only needs to check and check some simple checks, and then the image combination operation can be carried out according to preset fixed de-duplication, deletion and collage parameters. In addition, as a complement, the optical path design of the scanning structure also has a certain relationship with the light capturing unit 310, and under the conventional setting, a plurality of linear light sources or uniform light sources and a plurality of light capturing units 310 are coaxially arranged in a one-to-one matching manner, that is, at least one light source with an irradiation direction coaxial with the light receiving direction of the light capturing unit 310 exists near one light capturing unit 310. In this case, the light emitted by the plurality of light sources can uniformly illuminate the scanning object, and based on the light sources configured with the same parameters, the brightness of each area of the scanning object is basically kept consistent or has the same variation mode. This also provides convenience for later-stage combination of scanned images in general understanding, because based on scanned images with theoretically the same brightness, the combination procedure can use original version images to combine without or without adjusting parameters such as brightness, lightness, saturation and the like of the images in large quantity, and can reduce the reduction of scanning errors caused by defects of the plane of some scanned objects, such as shadows, misplacement, blurriness, resolution reduction and the like in the scanned images caused by factors such as protrusion, distortion, bending, defect and the like on the plane, and can make some post-remedies by uniformly arranged lights. However, the desired effect of the above-mentioned conventional arrangement scheme may not be fully realized in fact, and from the aspect of the arrangement of the light capturing units 310, although the light capturing units 310 arranged at regular intervals can obtain a stable image of the field of view, the light capturing units 310 arranged at opposite edges cannot completely cover the scanned object in the field of view, and at least a part of the area is replaced by a planar structure outside the edges of the scanned object. From the area ratio of the image of the scanning object in the field of view, the light capturing units 310 closer to the middle can obtain an effective image ratio closer to 100%, while the light capturing units 310 closer to the edge can obtain an effective image ratio of only 50-60%, or even lower, depending on the number of light capturing units 310 arranged and participating in the scanning work and the arrangement interval. At the edge position, because the effective image has a low ratio and is often located at the edge position of the field of view of a single light capturing unit 310, and because of the arrangement of the optical path of the camera, the imaging definition obtained by the camera is often high in the resolution of the middle area of the field of view, relatively low in the resolution of the edge area of the field of view and relatively serious in distortion, if the images appear in the light capturing unit 310 near the middle, the edge images can be removed in a mode of preferentially combining the same image content parts with higher resolution and relatively light distortion in the effective images obtained by the light capturing units 310 adjacent to the edge images. However, it is difficult for the light capturing units 310 responsible for capturing the edge images of the scanned object to do so, firstly, it is difficult for the effective images obtained by the light capturing units 310 at these portions to have the preferential combination of the images obtained by the adjacent other light capturing units 310, and in addition, from the light source perspective configured with the light capturing units 310, the light source at the edge of the scanned object may be influenced by the moving arm or other supporting components and side wall components set up at the edge to generate the problems of reflection, refraction, shadow, etc. different from the light source set up in the middle; in addition, even if the surrounding environment of the part of the light source is empty, the part of the platform structure 110 outside the edge of the scanning object is still inevitably irradiated, so that the problems of light reflection, diffuse reflection and scattering caused by the part of the light source are relatively serious, and accidental defect is more easily generated on the edge image data, so that the image distortion phenomenon is generated.

In the present embodiment, as shown in fig. 1, a new arrangement of the light capturing units 310 is proposed, and accordingly, in other preferred embodiments, the light sources associated with the light capturing units 310 also have the same configuration as the former. Specifically, in the present embodiment, if the distance between the adjacent light capturing units 310 is referred to as the viewpoint distance L, the viewpoint distances L between the light capturing units 310 in the present embodiment are not set equal; further, the sizes of the grooves are gradually reduced from the center to the edge. Here, the viewpoint distance L may be understood as a distance of a connecting line of centers of lenses or photosensitive elements of the light capturing units 310, more precisely, a distance of a connecting line thereof projected onto a plane parallel to the plane structure, which may be simply understood as a lateral distance between adjacent light capturing units 310 when the plane structure is parallel to the ground.

As described above, the viewpoint distance L decreases from the center to the edge, for example, it is assumed that the light capturing unit 310 closest to the center of the scanning member 300 is 1#, the adjacent two light capturing units 310 expanding to the two edge directions are 2#, and the viewpoint distance between 1# and 2# is L1; similarly, each 2# has another light capturing unit 3103# closer to the edge than 1#, and the viewpoint distance of 2# and 3# is L2; by analogy, there are 4#, 5#, 6# and so on, and the viewpoint distances are L3, L4 and so on, respectively. Then, in this embodiment, L1> L2> L3> L4> … > Ln. Assuming that the field of view of each light capture unit 310 is uniform and has a substantially conical configuration, the field of view of each light capture unit may be substantially rectangular after being cropped to correspond to the scan object. As described above, the fields of view of two adjacent light capturing units 310 overlap, and in the simplified rectangular field of view, the overlapping region is also configured to be substantially rectangular, and the width of the overlapping region along the arrangement direction of the light capturing units 310 may be referred to as an overlapping width D. As described above, the viewpoint distances decrease from the middle to the edge, and accordingly, in the case of the uniform field of view, the overlap width D increases from the middle to the edge, that is, the area of the region where the fields of view of two adjacent light capture units 310 near the edge overlap is larger than that of two adjacent light capture units 310 near the middle.

The above arrangement has the advantage that a large number of light capturing units 310, which are originally used for acquiring the middle area of the scanned object, are pushed out to the edge, so that the scanning quality of the edge is greatly improved without losing or greatly losing the middle scanning quality. In particular, as described above, since the light capturing unit 310 located near the middle region of the scanned object can completely cover the entire field of view by the content of the scanned object, and the light path located at the middle part is only responsible for illuminating the scanned object and therefore is less interfered by the external environment or the internal environment of the light capturing unit, the resolution, the reality and the quality of the image obtained by the light capturing unit 310 at this part are high, when processing the image obtained by the light capturing unit 310 of this type, the program can process the detail problem in the image through a simpler program, faster data processing and a smaller system occupation, and for the above reasons, the image obtained by the middle part at the edge of the field of view can still obtain relatively good image quality, for example, the distortion is relatively easy to process, and the image obtained by the light capturing unit 310 adjacent to the middle part can also obtain a scanned image with relatively good quality due to the proximity to the middle part, therefore, when the overlapped part images are spliced and combined, the image optimization can be carried out more quickly and simply without using excessive overlapped parts for mutual reference. The present embodiment sets the viewpoint distance of the light capturing unit 310 of the middle portion to be relatively large while also being able to secure the quality of the middle scanning portion. In contrast, as described above, the effective area of the edge portion of the field of view is too small, the light is easily affected by the wall and plane structures, and the image of the edge portion needs more reference images with better quality for correction, combination and preferential preservation, in this embodiment, the distance L from the viewpoint of the light capturing unit 310 near the edge portion is reduced, so that the increase of the overlap width D can make the scanned image at the edge have more opportunities to be mutually referenced and corrected with the adjacent scanned image, and the image combination can eliminate the interference of light, environment and the like, thereby obtaining a better image stitching effect. Especially for some scanning situations, the size of the scanning object is not fixed, the boundary of the scanning object just exceeds the field of view of the light capturing unit 310 capable of capturing the most peripheral position of the scanning object, at this time, to ensure that the whole range of the scanning object can be captured by the light capturing unit 310, another light capturing unit 310 closer to the edge is controlled to be turned on, in the case of a conventional equidistant setting, only a small part of the most peripheral range of the field of view of the light capturing unit 310 can capture some effective images about the scanning object, since the images are located at the edge of the field of view of the light capturing unit 310, and additionally, the unit is located in an edge environment with relatively more interference factors, and at the same time, the overlapping part of the unit with the adjacent light capturing unit 310 is less in the conventional setting, so that great difficulty is generated when the post-processing and combination are performed on the partial images, which in turn causes problems of undesirable distortion, loss, omission, etc. in the image of the part. For a scanned object, the content at the edge of the scanned object is often as important as the content at the center, for example, some page numbers, page labels, endorsements, signatures, stamps written at the edge of the page are important to the content integrity, validity and readability of the whole page. Therefore, by adopting the arrangement scheme of the light capturing units 310 provided by the embodiment, the overlapping fields of view between adjacent light capturing units 310 which are responsible for scanning the edge of the scanning object can be larger, in addition, the overlapping parts are relatively closer to the center of the field of view of each light capturing unit 310, the combination and splicing are performed based on the two overlapping partial images with better quality, most of the image distortion problems caused by the edge interference factors can be relatively eliminated, and the scanning at the edge can obtain better effect.

Preferably, in this embodiment, each light capturing unit 310 is further provided with at least one driver 320. The driver 320 is drivingly connected to the light capturing unit 310 to provide a movement drive thereof in the third direction. The driver 320 may be configured as a motor that raises or lowers the light capturing unit 310 by rotating and cooperating with gears.

Further, according to the above, it is preferable that the light sources are arranged so as to gradually increase the distance from each other from the center to the edge so as to match the light capturing unit 310. The light sources which are positioned near the center of the scanning object are relatively arranged dispersedly, because the middle part has relatively stable and single environment and has small influence on light rays, and the adjacent light sources can provide certain additional light rays for the peripheral position, so that only a plurality of light sources with slightly larger intervals are needed to provide stable and uniform illumination for the middle part of the scanning object; however, for the scanning object at the edge part, if the light sources are arranged in the normal equidistant manner, the light paths are affected by other structures such as the supporting arm, the supporting plate, the enclosure and the like at the edge, and the illumination is not ideal; secondly, even if the edge position is not affected by the other structures, the portion of the platform structure 110 beyond the edge of the scanning object inevitably exists, and inevitably, the portions also affect the irradiation effect of the light source due to light absorption, reflection, refraction, scattering and the like; thirdly, unlike the light source in the middle, the light source at the edge is lack of auxiliary light caused by another adjacent light source, which causes a natural defect of the light effect in the part, however, even if additional light source devices are arranged at the periphery for supplement, the energy consumption or the cost is not increased. The scheme adopted by this embodiment can avoid the above existing problems, and compared with the central portion, in this embodiment, the light sources at the edge portion are more concentrated, and the distance is shorter, so that one light source can obtain more auxiliary illumination from the adjacent light sources, and the illumination at the edge portion does not generate more than expected loss due to the additional component or the platform structure 110, and these losses can be offset by the enhanced illumination, and simultaneously, the image acquisition in this area by the light capturing unit 310 is more facilitated, and the two auxiliary components can make the image acquisition quality of the edge of the scanning object higher. In particular, the large-format scanning according to the embodiment can scan not only document and file objects printed by handwriting or a printer, but also paintings such as oil paintings, wash painting, silk cloth paintings, and the like, and for those articles created by using painting raw materials different from conventional writing or printing materials, for example, paintings using pigments such as oil pigments, mineral pigments, carbon pigments, and the like, especially, the scanning of some ancient scripts and paintings, cultural relics, and antiques, the influence of light on the pigment color thereof is great. Some light in special bands can affect some components in the pigment or the painting base, so that the pigment or the painting base can be photo-aged, and finally the problems of fading, color change, aging, fragility, fracture and the like of the calligraphy and painting are caused, which is not acceptable especially for antiques with high values. Although the LED technology adopted at present can avoid emitting the light wave band that influences these antique calligraphy and painting pigments to the greatest extent, but firstly this is very high to the design requirement of LED itself, and conventional LED can not use, and secondly although LED does not emit most infrared spectrum, it still produces heat, if the heat concentrates on calligraphy and painting intermediate position in a large number, still has great risk and can lead to the calligraphy and painting content by thermal ageing, causes the loss. The scheme adopted in the embodiment can better avoid the problem, the light source is gradually concentrated towards two edges, the region with dense light can be moved to the edges from the center, the edges of the common calligraphy and painting are picture frames or have no content, and the parts have no content, so that the aging loss of the parts can be avoided, and the scanning with protection can be carried out on the basis of not changing the original structure of the calligraphy and painting.

Preferably, the driving arm may be configured to drive the scanning member up and down according to a third direction, such as the structure shown in fig. 4, which is driven by a relatively mature double-screw driving manner in the prior art, briefly, the rotating motor drives the double-screw to rotate, and the moving platform moving on the double-screw drives the driving arm itself or the rest of the structures in the driving wall, which can be connected to the scanning member, to move up and down on the slide rail arranged along the third direction, so as to drive the scanning member to move integrally in the third direction. The driving scheme has a certain adaptive effect on a scanning object with a certain thickness, for example, the whole scanning component can be lifted upwards along the third direction aiming at a thicker scanning object, so that the light capturing unit in the scanning component can be focused accurately, and the adjustment precision meets plus or minus 0.1 mm. The double-screw can realize high-precision driving, and is high in driving capability and good in stability. Under the state that shows in the figure, the rotating electrical machines is not connected with lead screw transmission, during the in-service use, can connect through the mode that the centre set up the rotating head.

It should be noted that the above-mentioned embodiments are exemplary, and that those skilled in the art, having benefit of the present disclosure, may devise various arrangements that are within the scope of the present disclosure and that fall within the scope of the invention. It should be understood by those skilled in the art that the present specification and figures are illustrative only and are not limiting upon the claims. The scope of the invention is defined by the claims and their equivalents. The present description contains several inventive concepts, such as "preferably", "according to a preferred embodiment" or "optionally", each indicating that the respective paragraph discloses a separate concept, the applicant reserves the right to submit divisional applications according to each inventive concept.

Claims (10)

1. A non-contact type scanning device at least comprises,

a machine table (100) comprising at least a platform structure (110) for placing a scan object,

a scanning means (300) transversely disposed over the platform structure (110) in a second direction and for acquiring an image of a scanned object,

it is characterized in that the preparation method is characterized in that,

the scanning member (300) is configured to be movable over the platform structure (110) in a first direction to acquire an image of the scanning object, the scanning member (300) comprises a plurality of light capturing units (310) arranged in a line for acquiring at least a part of the image of the scanning object, wherein the light capturing units (310) are arranged in such a way that the viewpoint distances gradually taper from the center to the edge in the case that the viewpoint distances exist adjacent to the light capturing units (310).

2. The apparatus of claim 1, wherein the viewpoint distance is a pitch of adjacent light capturing structures, and wherein the viewpoint distance of the light capturing structures near the center is configured to be greater than the viewpoint distance of the light capturing structures near the edge.

3. The apparatus according to claim 1 or 2, characterized in that in the case of a setup in which the light capturing units (310) change gradually with a trend of viewpoint distance from the center to the edge, the overlapping areas of the fields of view of adjacent light capturing units (310) change in an increasing manner from the center to the edge, such that the images of the scanned object captured by the scanning means (300) have relatively more areas of their images at the edge positions that can be corrected against each other.

4. The apparatus according to any of the claims 1 to 3, wherein said scanning member (300) further comprises a plurality of light sources arranged in said scanning member (300) in a manner that at least the field of view of each of said light capturing units (310) can be illuminated, with said light capturing units (310) arranged in a tapered arrangement from the center to the outside.

5. The apparatus according to any one of claims 1 to 4, wherein the area of the scanning object illuminated by the at least two light sources at the edge position in the second direction is larger than the illuminated area at the middle position, so that the edge of the scanning object is illuminated by the light capturing unit (310) in a relatively good state.

6. The apparatus according to any one of claims 1 to 5, wherein the scanning member (300) is connected to the machine table (100) by driving arms (220) disposed at both ends, respectively, to form a state suspended above the platform structure (110).

7. The apparatus according to any of the claims 1 to 6, wherein each light capturing unit (310) is provided with at least one driver (320) configured to adjust its own position in the third direction, and the focal length of each light capturing unit (310) can be adjusted individually when adjusting the position in the third direction.

8. The apparatus according to any one of claims 1 to 7, wherein a driving structure (200) is disposed in the machine table (100), and comprises a driving rail (210) and the driving arms (220), the driving rail (210) is disposed on both sides of the machine table (100) along a first direction, and one end of at least two driving arms (220) extending along a third direction is movably connected to the driving rail (210), so that a moving direction of the driving arms (200) is defined in the first direction of the driving rail (210).

9. The apparatus according to any of claims 1 to 8, wherein at least two of the driving arms (220) are connected by a cross-bar, the driving structure (200) further comprising a driving assembly drivingly connected to the cross-bar for moving the driving arms (220) in a first direction.

10. The apparatus according to any one of claims 1 to 9, wherein the platform structure (110) is provided with a partial pressure assisting structure for assisting the flattening of the scanning object, and the partial pressure assisting structure is configured to be capable of flattening the scanning object on the platform structure (110) based on the generation of negative pressure on the platform structure (110).

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