DE2618195A1 - RETRO-RADIANT OPTICAL MULTIPLE X SCANNING DEVICE - Google Patents

Description

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Date
April 23, 1976
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Litton Business Systems, Inc., 34 Maple Avenue, Pine Brooks New Jersey, USA Multiple X retroreflective optical scanner

Summary: The invention relates to an optical scanning device for scanning and sensing information contained on an item bearing a label or tag; the Scanning device comprises a light source, a rotatable component with a reflective surface, an optical device, the light from the source to the reflective surface; and an optical device that directs light emanating from the reflective surface is reflected to form a scanning pattern on a predetermined plane; the scanning pattern consists of a large number of segments which together overlap at least a pair of Form X-shaped lines. The invention also relates to a An optical scanning station comprising means for generating a predetermined scanning pattern along a given plane and one of the scanning patterns device contained in the form of open slots, the slots coinciding with the given plane.

609847/0665

Account: Bayerische Vereinsbank (bank code 750 200 73) 5 804 248 Postscheckkonto Munich 893 69 - 801

Place of jurisdiction is Regensburg

2618_19_b_

The present invention relates to optical scanners and in particular on those optical scanning devices that are used at points of sale where objects, the coded tags, ι Labels or the like. Contain, can be read out automatically at a scanning station. I.

The known technique at point of sale has been developed so far;

that several methods for the automatic readout of a trailer or \

ί Labels have been suggested on a sales item. The coded information on the tag or label can be data such as the type ^! of the item, the price, the number of stocks, the name of the manufacturer and the like. In the case of retail or retail stores, a facility _f that is able to extract data of this type not only has the advantage that the passage to the test bench is accelerated and the possibility of errors for the operator is reduced, but also enables the data to be constantly changed, affecting inventory and sales volume, and finally the customer can also receive a fully specified sales receipt. Recently, items in retail stores have been provided with a coded label by the manufacturer that conforms to an industry regulation known as the Universal Product Code. This coded label contains; Data relating to the name of the manufacturer, as well as a catalog or stock number that identifies the respective product. A computer, which is addressed by the production and product inventory number decoded by the scanning device, is able to look up the current price as well as the current inventory information and make this available on the test bench. Such information can be printed on the customer's sales receipt or otherwise made known to the supervisory staff, as a result of which information is continuously changed and updated.

281819b

However, all of the techniques proposed so far have one or more Disadvantage. For example, an object can have the assigned coding

; th tag on the top or bottom or one of the side surfaces exhibit. With known facilities, the dsn test bench

; Operate the object as it approaches the scanning area, like this

! I.

orient that the trailer faces the scanning slot - is this if this is not the case, the scanner cannot scan the trailer. Such known devices also have to meet mandatory optical requirements that require specially designed optical components.

, borrowed, for example with regard to high precision _o common configurations of lenses and prisms. Such components are.

■ extremely expensive to manufacture and time-consuming to set up during, assemble and then wait in order to achieve the correct assignment.

Another disadvantage is that in known proposals complicated scanning patterns are required. Typical sampling patterns include Lissajous curves, multiple H curves, and multiple sine curves a. Not only are these patterns difficult to make, but they are there j the speed of the scanning beam is not constant in some cases

j, the sensed information is also difficult to decode.

In addition, conventional devices use a scanning technique that! is not perfectly reflective. That means that the sensor does not! is able to view only the spot passed through the scanning beam is lit, but actually a much larger area j

j considered. In known devices, this results in the requirement for

j large area sensors and high light levels along with the problem j the saturation of the sensor due to ambient light pick-up.

j Well-known facilities also make the use of glass plates

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necessary to cover the scanning slots. This happens because of the complex configurations of known scanning patterns that make an open slot arrangement mechanically possible. In the case of the glass plate, there is the risk of scratching when objects are guided over the glass plate during the scanning process; the glass plate must therefore often replaced * as the scratched glass reduces the pickup response of the Sensor would deteriorate. In addition, products or articles that contain a high level of residue contaminate or cloudy, e.g. in the case of meat or dairy products cause leakage or are exposed to such leakage, the glass, whereby a frequent cleaning is required.

With the present invention, an optical scanning device is proposed, which avoids inherent disadvantages of all previously known devices and at the same time ensures reliable operation and uses cheap components that can be easily assembled in a simple manner.

The scanning device according to the present invention is capable of the Tag- ^ adhesive or label part of an object to be scanned, the is present on any of the sides of the item or on its bottom. For example, if an object is in the scanning slot approaches, the sticker, tag or the like that appears on the back of the object can be read by the scanning device, without the operator at the test stand orienting the object in such a way that the sticker, tag or the like faces the scanning device j is.

In addition, the scanning device according to the invention is able to

% whether he is on

sv? dsr front

2613195

side of the packs appears. Even items that are in irregular Configurations are packaged, e.g. those that cause deformations or packs that have been deformed by incorrect handling can be read out with the aid of the scanning device according to the present invention. The customer or the operator at the test bench therefore needs not to sort the objects laboriously and time-consuming before scanning and orientate.

Another advantage of the invention is the use of optical Components which are conventional in nature and which are readily and cheaply available. Furthermore, the optical components are proportionate small spatial dimensions, as a result of which the scanning device can be built compactly, which also lowers costs. Since the inventive Facility represents a particularly expedient construction, becomes a Alignment during manufacture, as well as subsequent maintenance, in any simple manner without the use of complicated alignment and calibration equipment achieved.

Another advantage of the present invention is the simple scanning pattern, which in the preferred embodiment of the invention represents a double X pattern. Such a cough is not just easy to generate, but also gives the opportunity to scan a sticker, tag or the like, which is either on the front, the side surfaces, appears in the back or front of the object. Since each leg of the X is linear, the scanning speed is con- stant, which simplifies the construction of the associated decoder; will. ;

Due to the fact that the scanning device according to the invention a Using true retroreflective sensing technology, the sensor only receives the Spot area actually illuminated by the scanning beam.

considered. Thus, the sensor according to the invention is highly immune ^; against disturbing light influences from the environment. The sensor _;

dimension considerably reduced compared to known sensing elements! will.

Another advantage of the present invention is that the Ab-; slot receiving plate is open, whereby the use of a ' No glass cover plate, which can be easily scratched or tarnished! The plate according to the invention, which contains open slots, does not need to be cleaned, nor can it be worn or scratched, which would affect the scan pickup response.

According to the invention, a light source, e.g. a laser, is proposed for this purpose. directs the light beams through a series of adjustment lenses onto a beam splitter which divides the incident beam into two beams Splits. These two beams are each reflecting away from the mirrors on opposite sides of a rotating body drum When the drum rotates, the two light rays, which impinge on the reflective surfaces of the rotating body, reflect back and form pass-through tracks that hit the surfaces j of an additional pair of mirrors. The latter pair of mirrors | is arranged at an angle in such a way that the pass-through tracks are directed in such a way ^ that they fall in the plane on which the scanning slots are provided.

By appropriate design of the optical geometry, a multiple X-scan pattern obtained.

The invention is explained below in conjunction with the drawing an exemplary embodiment explained. Show it:

Fig. 1 is a schematic representation of the scanning device according to the invention /

Fig. 2 is a perspective view of the type of scanning slot surface

according to the invention, and
FIG. 3 is a sectional view taken along line 3-3 of FIG. 2.

According to Fig. 1, the output of a light source 10, for example a laser, which emits a parallel light beam 11, through a combination of a convex and a concave lens or through two convex lenses, which form a beam-shaping lens pair 12, directed, which changes the diameter of the light beam by magnification, while the property of the parallelism of the beam is preserved. A mirror 13 directs the broadened light beam 12a over a convex Lens 14 onto a beam splitter 15.

'The lens 14 is designed so that its focal length by the length of the The optical path from the lens to the scanning slit 25-28 is defined, the light beam converging on the plane in which the slit lies

The beam splitter 15 can be a mirror with a partially transparent front surface or a beam splitter cube with a square cross-sectional area. The light beam 14a that falls on the beam splitter 15, is split into two beams 16 and 17 of approximately equal intensity. The beam 16 is directed onto a fixed mirror 18 during the Beam 17 is directed to another fixed mirror 19. The Spiegejl 18 and 19 are arranged offset from one another by 180 in the preferred embodiment. However, there can also be additional mirrors in others Angular arrangements depend on the layout of the remaining optical Components to be arranged.

The rotating body 20 is a drum with reflective surfaces 41, 42, 43, 44 and 45. This rotating body 20 is shown with five reflective surfaces which have a cross section perpendicular to the axis of rotation

but it can have any number of reflective surfaces be turned. ι

A further improvement of the rotating body 20 enables an improvement in the scanning work cycle, whereby the speed of the information bits processed by the decoding circuit is reduced and '

so that the design of this circuit is simplified. '

In Fig. 1, the rotating body 20 is shown as a pentagon with a regular cross section. The vertex angle, or the angle between each ^: face, is 108. Each of the surfaces can be divided in the longitudinal direction into two half-H sections, for example sections 42a and 42b, which are arranged at an angle to one another.

This creates a ten-sided rotating body with a corresponding doubling the number of reflective surfaces created. The geometric properties of such a rotating body can be as follows: For one Angle between the split sections, e.g., between sections 42a and 42b of Figure 174, is the new vertex angle between adjacent ones Sections, e.g. between the divided right half of surface 41 and section 42a, 114 °.

For the angular relationships between the subdivided sections and the However, other values can also be selected for main areas in accordance with the present invention.

The rotating body can also have the shape of a right-angled pyramid or assume a right-angled truncated pyramid with η-sides, each side being reflective.

Rays of light reflected from the, surfaces of the mirrors 18 and 19

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hit the reflective surfaces of the rotating body 20 and are reflected back. When the rotating body rotates (either clockwise or counterclockwise) a light straw 1, which opens! hits one of its surfaces when moving or sweeping over j Reflected spot, the speed of which depends on the angular speed of the rotating body.

The mirrors 23 and 24 are angled with respect to the axis of the rotating body 20 arranged so that when the rotating body 20 is rotated, the geometrical location of the light rays reflected on the rotating body straight line patterns on a flat surface, e.g. the the mirror 24 and 23 follows. These straight lines of light are then reflected in a plane perpendicular to the axis of the rotating body 20 due to the angular orientation of the mirrors 23, 24. Through appropriate

Arrangement and angular dimensioning of the mirrors 23 and 24 can each be straight

ge line of light are executed so that in the scanning section plane an intersection is obtained, creating an X-pattern with an angle of 90 is obtained between each leg of the X.

The Lichtlinienzug which is reflected on the mirror 24, thus intersects the Abtastschlitzebene and forms one leg 27 of an X that is determined by the rotational speed of the rotating body 20. In a time interval later, the Lichtlinienzug which has been reflected at the mirror 23 intersects _f Sampling slot plane and forms the leg 25 of another X.

Although the drawing shows both legs 27, 25 for explanatory purposes shows that they are at the same time by reflecting the lines on their corresponding Mirrors 24, 23 are formed, the legs of each X are formed one after the other in actual operation.

609847/0665

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At the time zero, the beam 22, which is reflected on the surface 43 of the rotating body 20, strikes the right edge of the mirror 24.
0er beam 18a is reflected on the rotating body surface 45 and missed; just the left edge of mirror 23 and falls into empty space. ■ When the rotary body 20 rotates, the beam sweeps 22 the mirror 24 from right to left, whereby the first scanning beam 27 is formed;

that also migrates from right to left.

A little later, the beam 22 has reached the left edge of the mirror 24 and then falls into the empty space between the mirrors 24 and 23. The
Ray 19a then strikes the rotating body surface 42. That from the rotating body
20 reflected beam hits the left edge of the mirror at the beginning! 32 and moves towards the right mirror edge, causing the second
Scanning beam 28 is formed which sweeps from left to right.
During this part of the cycle, beam 18a is reflected by surface 45 into the void between mirrors 23 and 31. At a further point in time, the beam 18a on the rotating body is on the left
Edge of the mirror 31 is reflected, whereby the third scanning beam 26

that swipes from left to right. During this phase! the beam 19a through the rotating body into the empty space between the! Mirrors 32 and 24 reflected. ■

Finally, the beam 18a is reflected as beam 21 from the rotating body onto the right edge of the mirror 23, which forms the fourth scanning beam I 25, which sweeps from right to left. The beam 19a becomes
reflected in the space between mirrors 32 and 24. The one at the angle; arranged mirrors 34, 23, 31, 32 are equidistant in relation to; on the axis of the rotating body 20 along the circumference of an imaginary
Circle whose center coincides with the axis, arranged.
As the rotating body 20 rotates and passes the light beam across each of the angled mirrors, the beam from the mirrors is countered

609847/0665

; reflecting the corresponding scanning slots. Due to the angular orientation ; the four mirrors ; Scanning slots 25, 26, 27, 28 are projected to form a full circle.

If an object moves across the scanning slots 25, 26, 27, 28

'in the direction of the viewer, the mirrors 31, 32 project the Abi
scanning beam sequentially in a direction away from the viewer

slots 26 and 28 so that the scanning beam is able to enter

Label or the like · that is on the front or left side or on the ! to feel

/ Appears on the front or right side. Projected in a similar way

the orientation of the mirrors 24 and 23 sequentially moves the scanning beam through the slots 27 and 25 and can be used as a tag, label or

Like. Scan that on the rear or right side or the rear ι or left side occurs.

ι A label or the like that appears on the underside of an object can scan one of the four scanning beams properly.

The scanning device according to the invention is able to read a label or the like. Having object to be scanned when the label on the bottom, the front, the back or the right or left Page appears. Even items that are packaged in irregular configurations, e.g. products or packaging that have been deformed [i can be read in a similar manner as one or more scanning beams sweep over the label. If a label is incomplete when the scanning beam was scanned for the first time, the missing parts of the label information can be found in the Encoders can be fed in during subsequent scans as each item is automatically scanned many times before it is out the scanning slot surface can be moved out.

609847/0665

As discussed above, encoded labels are intended to be used by device according to the invention are scanned ^ around the contained therein To decode information. The UPC label has alternating stripes of light and dark or other contrasting color. if the scanning beam one after the other one of the four double-X patterns forming slits; if the label is applied by the beam or illuminated several times.

Light from the scanning beam is differentiated from the surface of the

j The label is dlffundisrt depending on whether a light or dark strip is illuminated. Dg the scanning beam is continuous; moves ^ is a modulated sequence of diffused light pulses ER j _f demonstrates the intensity of YND period of the color and width of the strips depends I »ι

The modulated light pulses follow the exact path as the scanning beam., which illuminates the label of the item, creating a retroreflective Recording is obtained. Assuming that the beam 27 is off a label

has scanned, the modulated pulses enter the scanning slot, the associated with the scanning beam 27, and strike the mirror 24

on, which reflects the pulses onto the surface 43 of the rotating body 20.

Two sensors, shown schematically by 30a, 30b in Fig. 1, are arranged near the rotating body. Convex lenses 28, 29, the! Sensors 30a, 30b are assigned, collect the modulated light pulses,

which are reflected from the surfaces of the rotating body 20, and direct j the light on the sensitive elements that make up each sensor. In In the above example, only the sensor 30b responds to the modulated light im- ' pulses that impinge on the surface 43 of the rotating body 20.

The sensor thus takes a series of changing light pulses

609847 / 066H

Intensity and duration according to the stripes on the coded label

on. The sensor, which is a transducer, changes the light energy it receives

! into a corresponding electrical signal, which is then amplified and a

corresponding decoding circuit is supplied.

Since the light that returns from the scanned object, one

On the other hand, a single sensor can follow a real back-reflecting path be arranged behind the beam splitter 15 along the beam path 14a.

The mirror 13 can be semi-silvered and partially translucent! be formed so that it is possible to arrange the sensor behind the mirror in an extension of the beam path 14a.

In Fig. 2 a part of a test stand 60 is shown, which also a part of the scanning system according to the invention. The double X scan pattern is, as the drawing shows, formed in a cover plate 61, the upper surface of which is flush with the opposite surface of the test stand is trained.

The first X-slot, which consists of two slots 62, 63 of the same length which intersect at right angles, engages in a second X-slot, the consists of slots 64, 65 of equal length which form a grid. The slots are formed in the cover plate 61, which are releasably attached to the associated Counter surface and the housing for the optical components attached or hinged (Fig. 3). The cover plate 61 can thus be moved to have access to any residue passing through the slots have fallen into the interior of the case. Such residues fall outside the path of the light rays so that the operation of the device is not impaired.

! The edge of the plate 61, which forms the slots 62, 63, 64 and 65, can be designed as a beveled edge 67 , so that the possibility that

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objects move across the scanning slots on the edge of the opposite slot caught, is largely turned off.

The central area defined by the intersection of the slots 62-65, which would otherwise be empty and which would allow objects to fall into the housing of the device, has a cap 70, the top of which is flush with the top of the plate 6 \. and the opposite surface lies. The edges of the cap 70 are similarly bevelled at 72 to allow objects to be moved away from the interior of the housing. The cap 70 is received by a column 71 which is preferably coaxial with the axis of the rotating body 20.

The other optical components are inside the housing of the test stand 60 arranged in the area below the cover plate 61 and the cap 70.

The embodiment shown shows the scanning of objects from below when they move along the test stand 60 upside down over the cover plate 61, but the objects can can also be scanned from above by reversing the position of the housing of the device, and the objects can be below the scanning device at any distance from the slots 62-65 through itself- + be guided. !

Although the generation of a double X scanning pattern has been explained in the exemplary embodiment according to the present invention, it is possible within the scope of the present invention to generate a pattern that represents multiple X scanning patterns, in_dem simply the number of at an angle arranged-i ^! th mirror is enlarged and the shape of the rotating body 20 is modified;

609847/0665

Claims (1)

- 15 claims Θ Optical scanning device for scanning and sensing information part absorbing! on a sticker, tag or the like / objects j by a rotating body (20) with a reflective surface (41 j to 45), a first optical device (15) which directs light from a light source (10) onto the surface (41 to 45), a second optical device (23, 24) which directs light reflected from the surface (41 to 45) and a scanning pattern on a Forms a predetermined plane, which consists of a plurality of segments that overlap each other at least one pair form cross-shaped lines (25 to 28). '2. scanning device according to claim 1, characterized in that the second optical device (23, 24) is a reflective device which directs the light by reflection. 3. Scanning device according to claim 2, characterized in that the , reflective device (23, 24) has mirrors around the The axis of rotation of the rotating body (20) are arranged. 4. Scanning device according to claim 3, characterized in that the Mirror (23, 24) offset at the same angle with respect to the axis are. 5. Scanning device according to claim 4, characterized in that the Mirror (23, 24) are offset at the same distance from the axis. 6. Scanning device according to claim 1, characterized in that the ί Rotary body (20) made of a large number of flat surfaces (41-45) 609847/0665 consists of a polygon in cross section with respect to the axis of rotation of the body (20). 7. Scanning device according to claim 6, characterized in that the Polygon is a regular polygon. 8. Scanning device according to claim 7, characterized in that each the same-sided surfaces (42) in the longitudinal direction into two sections j (42a, 42b) is divided so that the two sections (42a, 42b), the | assigned to each end face, a V-angle with a first value and adjacent sections associated with each adjoining face form a V-angle with a second value. 9. Scanning device according to claim 8, characterized in that the first angle value is different from the second angle value. 10. Scanning device according to claim 1, characterized in that the first optical device (15) a beam splitter for dividing a light beam from the light source (10) into first and second Having rays (16, 17) and that first and second reflectors (18, 19) are arranged in the paths of the first and second rays (16, 17) are, each reflector (18, 19) directing its associated beam onto the surface of the rotating body (20). 11. Scanning device according to claim 10, characterized in that a beam-shaping lens device (12) between light source (10) and: first optical device (15) is inserted, 12. Scanning device according to claim 10, characterized in that one The focusing lens (14) is inserted between the light source (1O) and the first optical device (15), the focal point of which is the scanning plane 609847/0665 coincides. 13. Scanning device according to claim 1, characterized in that a sensor arrangement (30a, 30b) in the optical path between the light source! (1O) and the receiving plane scanning pattern is inserted, and that '·. the sensor arrangement can receive scanned information which j Associated with a sticker, tag or the like. Receiving object following a path related to a generated,! This scanning beam following this optical path is reflected back. , 14. Scanning device according to one of claims 1 to 13, characterized; characterized in that the means (10 - 45) ^j reasonable in a housing (60) is arranged, whose upper side comprises open slots (62 to 65) corresponding to the scan pattern. 15. Scanning device according to claim 14, characterized in that the j Top is a flat plate (61) that will outline the pattern in the form of slots (62-65). 16. Scanning device according to claim 15, characterized in that the Plate (61) is movably attached to the housing (60). 17. Scanning device according to claim 16, characterized in that the has a cap (70) defined by the intersection of the cross-shaped lines. 18. Scanning device according to claim 17, characterized in that the Cap (70) is formed coplanar with the plate (61). 19. Scanning device according to claim 18, characterized in that the Cap (70) is rigidly attached with respect to plate (61). 609R47 / 0665 20. Scanning device according to claim 15, characterized in that the edge (67) of the slots (62-65) is beveled. 21. A scanning device according to claim 17, characterized in that the Edge (72) of the cap (70) is beveled. 22. Scanning device according to claim 16, characterized in that the plate (61) _{is attached to the housing (60) via a G e} ± nk. 609R4 7/066 Blank page