DE102006035733A1 - Scanning device for scanning samples, particularly books, has table for overlaying sample, and lighting mechanism arranged above table, where imaging system is provided, and optical line sensor is synchronously moved with illuminated sample - Google Patents

Abstract

The scanning device has a table for overlaying a sample, and a lighting mechanism arranged above the table. An imaging system is provided, and an optical line sensor is synchronously moved with the illuminated sample. The lighting mechanism is formed by two illuminating arms (12,13) which are arranged to both sides of a table centre plane perpendicular to the scanning direction. The movement of the illuminating arms is controlled in such a way that the sample, illuminated by them, is brought up as cover on sample. An independent claim is also included for a sample table for a scanning device.

Description

The The invention relates to a scanning device for scanning Templates, in particular books, with a table to support the template, one above the table arranged lighting device that is capable of on the Illuminate the table-top device line by line in the scanning direction, and with an imaging system and an optical line sensor, which is movable synchronously with the illuminated template line, so that the illuminated template line is always displayed on the line sensor is.

Such a device is in the DE 103 40 490 A1 described. The lighting device consists of an elongated light that illuminates a narrow template line on the original. Fixedly connected to the lamp is an objective as an imaging system, behind which is a line-shaped, optical sensor, which is arranged in a region of the image plane of the lens, so that the illuminated line is imaged on it.

To the Sampling the original will remove the entire array of illumination equipment, Lens and optical sensor pivots and thereby the template total scanned line by line. To keep a constant distance between the lighting device or the lens on the one hand and the to have each lit line on the template on the other hand is at the same time by the pivoting movement of the lamp a forced tour move vertically.

adversely with such an arrangement, it is because of the near the lens lying lighting device is not always an optimal illumination the template is given.

The Invention is thus based on the problem of line by line illumination to improve the template.

to solution of the problem, therefore, the invention provides that the lighting device is formed by at least two lighthouses, on both sides arranged perpendicular to the scanning direction center plane of the table and whose movement is so controllable that those lit by them Lines on the template are always brought to coincidence.

On this way it is achieved that the respective template line of two sides is lit laterally. This results in a uniform illumination without shadow, what a particularly high-contrast picture also with Templates results that have only low contrasts.

Around To obtain a simple structure, each light arm has a light line and a rod lens arranged in front of it, which illuminates the light line so focused that lit on the template a narrow Line is present, each light arm by means of a motor to a stationary axis of rotation is movable. This way only needs the lighting arm to be moved about a stationary axis of rotation to thereby to be able to illuminate the entire template line by line.

Around To synchronize the rotations of the light arms, the controller has the system has a synchronization unit with the engine control is connected, wherein the motors of the two lighting arms controlled so be that the document lines illuminated by them always are brought to cover.

The Synchronization unit is simultaneously with the power control connected to the light line, so that the luminosity of the light lines to the while changing a rotary motion Distance to template is adjusted. The further, therefore, the more to be illuminated Template line is removed from the respective light arm, the larger it gets set the power consumption, so that a corresponding consistent Light intensity present on the template.

Of Furthermore, the imaging system is fixed, preferably in the mentioned Table center plane arranged, and only the line sensor on a slide in the image plane of the imaging system synchronously moved to the rotation of the light arms, including the control of the carriage connected to the synchronization unit.

Preferably is for the movement of the line sensor in the image plane at a constant speed given, so that is given, which line on the template is being displayed. The rotation of the two light arms must be the consequences.

Around especially when scanning books one possible plan to maintain plane, the invention further provides that the table consists of two plates, which are in the middle plane are spaced apart from a gap, each plate being bound Feathers carried on a support is attached.

About the open book is folded a transparent pressure flap, which defines the template level to be mapped.

The open book is placed on the table so that the spine is between the two plates and one book page on each ner of the plates. Depending on the thickness of the respective book page, the underlying plate is pressed down so that the two open sides are pressed from below against the pressure flap and thus lie in one plane.

Around also the spine to wear and from damage to protect, the gap is covered by a cloth, wherein the cloth is wider than the gap and being on one longitudinal side attached to one plate and on the other long side over a Rod led and is resiliently mounted below the rod.

alternative To the resilient mounting of the plates, each plate can be individually motorized be arranged movable. The drive control is force-dependent. each Plate moves each resting on her book page against the overlying pressure flap. As soon as the counterforce generated by this process has a certain value, it becomes the drive is switched off. Also in this way it is achieved that the pages to be scanned as possible lie in one plane.

Around preferably Save energy, the lights are from a variety of juxtaposed individual lights composed individually can be controlled, with only the individual lights on necessary to illuminate the template across its width.

The Scanning device further comprises a buffer, the stores the picture information pixel by pixel, this file being a Image processing available can be made. It is thus based on a compression of the data waived completely to the obtained image information to pass on an image processing program.

As mentioned earlier, A folding flap is provided on the template is flattened to define a plane object plane. These Flap may preferably be at the front of a hanger in the depressed Held position. With the strap is also a switch to trigger connected to the scanning process, so as soon as the bracket on the pressure flap snaps into place, the scanning process starts automatically.

The Invention also relates on a scanning device for scanning templates, in particular of books, with a table to support the template, one above the table arranged oblong Lighting device that is capable of being on the table Illuminate template in the scanning direction line by line, as well with an imaging system and an optical line sensor, the is synchronous with the illuminated template line, so that the illuminated template line always displayed on the line sensor is.

In order to the template of the optical line sensor at each point proportional is recorded for the gray and / or color levels present in the template, In such a device, the illumination of the template line on their whole length be very even and must not change when feeding the scan line. Especially a color original can only ensure a uniform illumination that the colors of the template also in equal intensity and saturation be detected by the line sensor.

Known elongated Lighting equipment for Scanners consist of several adjacent, at a great distance mutually arranged light sources whose light by means of a behind the light sources arranged rotationally symmetric concave mirror projected in the form of a cone on the respective template line become. The cones of adjacent light sources overlap, wherein the light intensity on the template line according to the distribution pattern of the light sources fluctuates. The places of the template line, the one light source exactly opposed, become more illuminated as the intermediate areas.

By The concave mirror will also light the light sources across the template line fanned, so that a wide strip is illuminated, from the sensor line can not be captured in its full width. It will thus produces more light than is necessary.

The Invention is thus also based on the problem of a uniform and economical To achieve illumination of the template lines.

to solution of the problem, the invention provides that the lighting device is formed by at least one luminous arm, in which a plurality from point light sources in the direction of a template line, close together lying in at least one light line are arranged.

By This arrangement is due to the high number of light sources and their dense arrangement in terms of high uniformity of light intensity on the longitudinal extent scored the template line. The radiation cone can also be very be kept small so that a template line is not very wide is.

A very high uniformity at one possible Low construction cost is achieved when the distance between two adjacent point light sources is less than or equal to 0.5 cm.

Around to focus the light of the light line on the template line, a rod lens is arranged in front of the light line or the light lines, the light of the light line in planes perpendicular to its longitudinal extent focused.

Thereby the width of the scanning line can be more clearly on the width of the be concentrated by the optical line sensor detected line.

Preferably the point light sources can be controlled individually or in groups. As a result, the lighting range of the original size can be adjusted. In addition, can the luminosity to be enlarged when scanning the template, the distance between the light arm and the respectively illuminated template line.

For a good Color rendering is provided that the point light sources a white light produce.

When Point light sources are preferably LEDs used.

The The invention further relates to a presentation table, in particular for one Scanning device of the type described.

Around To get good scan results, the template to be scanned should be preferably be flat so that they are in an imaging plane of the imaging system lies. With opened books This is difficult to realize because the unfolded book halves on spine in two a wedge-shaped Incision forming flanks converge. It therefore looks like that the presentation table consists of two parts, on each of which one half the book comes to rest, with the spine in a gap between immersed in the parts of the master table. The two parts of the master table are set to different heights, so that the respective top Book pages of opposite book halves on a height to come to rest.

Especially with very thick books it is difficult to find the area of the book page that is close to the spine to bring in a horizontal position.

The Invention is thus based on the problem of providing a document table, which is suitable for scanning books of different thicknesses.

to solution of the problem the invention provides that the presentation table consists of four part tables, which are arranged in the quadrants of a cross lattice and the independently from each other are perpendicular to the plane of the template movable.

One Book can therefore be in two mutually perpendicular orientations be placed on the template table, with the template line either parallel to the spine or perpendicular to it.

Especially a vertical orientation has the advantage that even with the Use only one light arm the flanks of the wedge-shaped incision be well lit and cast no shadows.

Preferably run between the part tables two vertically aligned column, one gap being wider than the other. In this way can for every type of book the optimal alignment to the template line will be chosen.

in the The following is based on an embodiment the invention closer explained become. This shows the

1 a perspective view of the scanning device in a first embodiment,

2a a cross section through a light arm,

2 B a longitudinal section through a light arm,

3a a top view of a scanning device in a second embodiment,

3b a cross section through a scanning device according to 3a .

4 a detailed representation of the pressure flap,

5 a schematic representation of the operation of the device,

6 a plan view of a light arm with a plurality of LEDs and

7 a four-part presentation table.

The scanning device consists of a base frame 1 , on which two horizontally arranged plates 2 . 3 are juxtaposed, which form a table for the edition to be scanned. The gap between the plates 2 . 3 marks a vertical table center plane 49 (see also 5 ), to which the arrangement is constructed mirror-symmetrically. According to the embodiment of the 1 are these plates 2 . 3 independently of each other in vertical rails 4 . 5 kept movable by motor. The rails 4 . 5 are in a back wall 6 of the base frame 1 ,

Above the plates 2 . 3 there is a transparent pressure flap 7 , preferably made of glass, which is slightly larger than the common area of the two plates 2 . 3 and the pivotable on the base frame 1 in pivot bearings 8th . 9 is stored. In the pivot stores 8th . 9 Springs are arranged to ensure that the pressure flap 7 if it is not mechanically held in the illustrated horizontal position, automatically works upwards to z. B. the edition of an unfolded book on the two plates 2 . 3 to enable. In the horizontal position, the support resting on the table presses against the pressure flap from below 7 whose downwardly facing surface thus defines the imaging surface to be imaged.

To form a lighting device are on both sides of the table center plane 49 from the base frame 1 two up and out looking support arms 10 . 11 off, at the outer ends of each a light arm 12 . 13 is rotatably mounted about its longitudinal axis. Every light arm 12 . 13 extends in the horizontal direction parallel to the table center plane. In the light arms 12 . 13 there is one light line each 14 . 15 and a rod lens in front of it 16 . 17 that are as long as the table is deep. Every light line 14 . 15 Produces a light wedge with a small opening angle, so that each light arm 12 . 13 a document line extending in the document surface parallel to the table median plane completely illuminates (see also 5 ).

Above the table is in the middle of the table on a mast 18 a head 19 mounted in which is a lens 20 located. Above the lens is in the head 19 - Not visible in this figure - an optical line sensor which extends parallel to the table center plane and the means of a carriage in the image plane of the lens 20 can be moved perpendicular to the center plane of the table.

In the 2a and b is a light arm 12 shown in more detail: A light arm 12 consists of an elongated luminaire housing 21 whose foot 22 is executed circular and otherwise has a mushroom-shaped cross-section. In the head of the mushroom is located between two rail-like holders 23 a circuit board 24 , on the formation of a light line, a series of light-emitting diodes 25 are arranged, which produce the darkest possible light. In front of this light line is the rod-shaped lens, which focuses the light in one line.

In the foot 22 are a stepper motor 26 and a planetary gear 27 , Between the housing of the stepper motor and the inside of the foot 22 of the light arm is a warehouse 28 so that the light arm housing 21 rotatable on the stepper motor 26 is stored. The bottom of the stepper motor is on the support arm 10 (respectively. 11 ) attached.

The 3a and b show a further embodiment of the scanning device in the form of a tabletop device. Its structure is largely consistent with the scanning device described above, although the plates 2 . 3 are not kept movable in rails movable by motor, but in each case on four bound springs 30 are stored, each on a base 31 stand. 3a shows a plan view of the table top device, wherein the support arms 10 . 11 , the light arms 12 . 13 , as well as the head 19 with the optical line sensor according to the embodiment 1 matches. The plates 2 . 3 are each in four places 32 , formed by the vertices of a rectangle, on feathers 30 supported. A cornerstone is in 3a through the head 19 covered. These stand, as is the side view of the 3b shows, on the base 31 that have a raised edge 33 having. The plates 2 . 3 have a down-facing edge 34 who is the edge 33 the base 31 overlaps, leaving each plate 2 . 3 with the associated base 31 forming a box.

At the springs 30 are cylindrical springs, which are at both ends of a disc 35 support it via a telescope 36 connected to each other, which is the extent of the spring 30 limited. The plates 2 . 3 can thus counteract the force of the springs 30 are pressed down, with each spring yields according to the thickness of the template.

Between the two plates there is a gap, that of a cloth 37 is covered. The cloth 37 is guided on a longitudinal side via a rod and mounted resiliently below the rod, which is not shown here. This arrangement makes it possible to lower the back of a book in the gap.

On the front of the device is a acting as a lock bracket 38 , which is placed over a frame of the folded down pressure flap 7 attacks. This determines the position of the unfolded pages of the book and the springs according to the thickness of the plates 2 . 3 lying on the book halves pressed down. The spine is located in the gap between the plates.

With the strap 38 a switch is connected, which in turn is connected to the scanning device, so that with a closed bracket 38 the scanning process is triggered automatically.

According to 4 there is the pressure flap 7 from a glass pane 39 and is in a metal frame 40 held whose base is interrupted. One attachment each 42 the base of the frame extends through an approximately cylindrical bearing housing 43 the pivot bearing 8th . 9 and is in their end faces 44a , b stored. Coaxial with the extension piece 42 is located in the bearing housing a cylindrical spring 45 with one end on an end wall 44a of the bearing housing 43 and with her other end on the lug 42 is attached. The spring is biased to hold the pressure flap 7 always pushing to be worked up.

Not shown in detail is the arrangement of the line sensor in the head 19 , This is located on a sled, which has two guides. The carriage is connected to a toothed belt, which is also driven by a stepper motor.

In the 5 the operation of the device is explained: The control of said motors M, so both for the line sensor 46 as well as for the light arms 12 . 13 , is with a synchronization unit 47 connected, which controls the motors M, that of the two lighthouses 12 . 13 illuminated template lines 48 are brought to coincidence and the line sensor 46 is in the image plane at a location where the illuminated template line 48 in front of the lens 20 is shown.

The synchronization unit 47 continues to ensure that the light intensity in the respective template line 48 remains the same during scanning by the power of the individually controlled lights is increased or decreased accordingly.

The Device is also provided with a detection device, which determines the size of the template. Accordingly, the scanning is limited over the length of the original, so that the individual lights that are outside the width of the template lie, not be turned on.

A light arm 12 . 13 owns, like that the 6 shows a variety of in one or more lines, if necessary 50 closely spaced LEDs 51 that give off a white light. The preferred distance of the approximately 5.3 mm diameter LEDs is approximately 6 mm measured from center to center. The LEDs emit their light in a cone of light. Since the LEDs are close together, the cones overlap several times, so that the light intensity at approx. 15,000 to 22,000 mcd in the direction of the light line runs very smoothly and without fluctuations. By means of the front of the light lines 50 arranged rod lens 16 , that will be from the light line 50 emitted light is focused in a straight line parallel to the light line, because the rod lens 16 The light thus focused only in the planes perpendicular to their longitudinal extent.

The presentation table 52 according to 7 consists of four part tables 52a . 52b . 52c . 52d , which form the quadrants of a cross and which are independently spring-mounted and thus adjustable in height. The storage of each part table is carried out on four biased by a bond springs. Between the part tables 52a . 52b . 52c . 52d two run a cross-forming column 53a . 53b So that a book, depending on the alignment with his spine, either in one or the other gap 53a . 53b to come to rest. Since the gaps are different widths, books of different thicknesses can be unfolded as flat as possible on the original table. The wider gap runs parallel to a light arm 12 . 13 ,

The Alignment of the spine transverse to the light arm has the advantage that the areas of the sides near the spine can be illuminated shadow-free, so that the scanning device only over have a light arm needs to get a uniform illumination to reach the entire book page.

1

base frame

2

plate

3

plate

4

rail

5

rail

6

rear wall

7

Anpressklappe

8th

pivot bearing

9

pivot bearing

10

Beam

11

Beam

12

Leuchtarm

13

Leuchtarm

14

light line

15

light line

16

rod lens

17

rod lens

18

mast

19

head

20

lens

21

Leuchtarmgehäuse

22

foot

23

holder

24

circuit board

25

led

26

stepper motor

27

planetary gear

28

camp

29

30

feathers

31

Base

32

Put

33

edge

34

edge

35

disc

36

telescope

37

cloth

38

hanger

39

pane

40

metal frame

41

42

extension

43

bearing housing

44

front

45

feather

46

line sensor

47

synchronization unit

48

template row

49

Table midplane

50

light line

51

LED

52

dividing table

53

gap

Claims (18)

Scanning device for scanning documents, in particular books, with a table for supporting the document, an illumination device arranged above the table, which is able to illuminate the document lying on the table in the scanning direction line by line, and with an imaging system and an optical line sensor , which is movable in synchronism with the illuminated template line, so that the illuminated template line is always imaged onto the line sensor, characterized in that the illumination device of at least two light arms ( 12 . 13 ) is formed on both sides of a perpendicular to the scanning direction center plane ( 49 ) are arranged and their movement is controllable such that the illuminated by them template lines ( 48 ) are always brought to coincidence on the template. Scanning device according to claim 1, characterized in that each luminous arm ( 12 . 13 ) a light line ( 14 . 15 ) and a rod lens arranged in front of it ( 16 . 17 ), which focuses the light of the light line in such a way that on the original a narrow illuminated template line ( 48 ), each light arm ( 12 . 13 ) is movable by a motor M about a stationary axis of rotation. Scanning device according to claim 2, characterized in that the motors M are stepping motors which are controlled by a synchronization unit ( 47 ), the synchronization unit ( 47 ) is connected to the power control of the light line to the luminosity of the light lines ( 14 . 15 ) to adapt to a changing distance to the template. Scanning device according to claim 3, characterized in that the imaging system is fixedly arranged and the line sensor ( 46 ) on a slide in the image plane of the imaging system in synchronism with the rotational movement of the light arms ( 12 . 13 ), for which the control of the carriage drive with the synchronization unit ( 47 ) connected is. Scanning device according to one of the preceding claims, characterized in that the table consists of two plates 2 . 3 exists in the middle of the table ( 49 ) are separated by a gap and the bound by springs ( 30 ) carried on a base ( 31 ) are attached. Scanning device according to claim 5, characterized in that the gap of a cloth ( 37 ) is spanned. Scanning device according to claim 6, characterized in that the cloth ( 37 ) is wider than the gap in the basic position of the plate, wherein one side of the cloth ( 37 ) is guided over a rod attached to one of the plates and is resiliently held on this plate. Scanning device according to one of the preceding claims, characterized characterized in that the illumination means of a plurality of arranged side by side individual lights, which can be controlled individually are and that at the edge of the line be sensitive individual lights dependent stay off the width of the template if necessary Scanning device according to claim 1, characterized in that that the control of the scanning device has a buffer, which stores the image information with pixel accuracy. Scanning device according to claim 1, characterized in that above the table a pressure flap ( 7 ) is arranged from transparent material, preferably glass, which is foldable on the table, and that at the front of the scanning device, a bracket ( 38 ) is to fix the flap, with the bracket ( 38 ) a switch for triggering a scan is present. Scanning device for scanning documents, in particular books, with a table for supporting the document, an elongated illumination device arranged above the table, which is able to illuminate the document lying on the table in the scanning direction line by line, as well as with an imaging system and an optical system Line sensor, which is movable synchronously with the illuminated template line, so that the illuminated template line is always mapped to the line sensor, characterized in that the illumination device of at least one light arm ( 12 . 13 ) is formed in which a plurality of point light sources in the direction of a template line closely adjacent to each other in at least one light line ( 50 ) at are ordered. Scanning device according to claim 11, characterized in that that the distance between each two be adjacent point light sources is less than or equal to 0.5 cm. Scanning device according to claim 11 or 12, characterized in that in front of the light line ( 50 ) a rod lens ( 16 . 17 ) is arranged, which the light of the light line ( 50 ) is focused in planes perpendicular to its longitudinal extent. Scanning device according to one of claims 11 to 13, characterized in that the point light sources individually or are controlled in groups. Scanning device according to one of claims 11 to 14, characterized in that the point light sources a white light produce. Scanning device according to one of claims 11 to 15, characterized in that the point light sources LEDs ( 51 ) are. Master table especially for a scanning device according to one of the preceding claims, characterized in that the master table consists of four partial tables ( 52a . 52b . 52c . 52d ), which are arranged in the quadrants of a cross-lattice and which are movable independently of one another perpendicular to the plane of the template. Template table according to claim 17, characterized in that between the part tables ( 52a . 52b . 52c . 52d ) two mutually perpendicular gaps ( 53a . 53b ), whereby the one gap ( 53a ) is wider than the other ( 53b ).