WO2002075637A1

WO2002075637A1 - Reader with an image recording unit for reading a code and method for reading a code

Info

Publication number: WO2002075637A1
Application number: PCT/DE2002/000957
Authority: WO
Inventors: Jörg Küchen; Frank Müller
Original assignee: Gavitec Ag
Priority date: 2001-03-19
Filing date: 2002-03-15
Publication date: 2002-09-26
Also published as: DE10291122B4; DE10113426A1; DE10291122D2

Abstract

The aim of the invention is to improve the reading of a code. To this end, a reader (1) comprises an image recording unit (9) for reading a code (15), especially for reading a bar code, a two-dimensional code, a three-dimensional code or a color code, which is characterized in that a spacer (7) between the image recording unit and the code is provided with at least one illumination device (14) that illuminates the code preferably from the side.

Description

Reading device with an image recording unit for reading a code and method for reading a code

The invention relates to a reading device with an image recording unit for reading a code, in particular for reading a bar code, a two-dimensional code, a three-dimensional code or a color code, with a spacer for reading the code at a distance.

The marking and coding of an object is becoming increasingly important in the course of increasing automation in many areas, in particular in the area of automatic identification. Here, the object is provided with a machine-readable code, various methods being used to mark the object. On the one hand, an object is marked indirectly, in which the code is applied to a label and the label is attached to the object to be marked. On the other hand, the marking is also applied directly to the object to be marked. In particular, the marking of an object in an industrial environment is becoming increasingly important, with the direct marking of the object being preferred over the use of labels for marking an object.

However, the direct marking of an object has the disadvantage that an apparatus which is used for reading a code has to meet increased requirements in the area of reading ability. Such a reading device is, for example, a scanner which is used stationary or mobile.

The increased demands on a reading device result, for example, from the fact that the nature of a surface of a marked object depends on the manufacturing process and is normally not adapted to the requirements of the reading device. But also the variety of methods for the direct marking of an object increases the demands on a reading device, since this has to cover the entire range of marking methods. For example, a code is applied with color, burned in with a laser or engraved or pressed in with a tool.

An important class of apparatus for reading a code consists of the actual reading device and a device for illuminating the coded area. Here, the reading device essentially consists of an image recording unit which is connected to a computing unit. The image acquisition unit usually consists of a lens and a light-sensitive sensor, which is manufactured using semiconductor technology (CCD or CMOS). The lighting unit can in this case be permanently connected to the reading device and / or the image recording unit or else be arranged independently thereof.

Here, the light emitted by the lighting unit and / or another light source is partially reflected in the area of the coded surface. This reflected light is picked up by the image recording unit and processed by the computing unit for the purpose of code reading. Appropriate lighting of the coded area is necessary so that the image recording unit can take a clear picture of the code. A clear picture of the code is an essential prerequisite for a reliable reading result. In principle, reading is also possible without a lighting unit using only the scattered light of an ambient light. However, a lighting unit is always required when consistently reliable code readings and extensive readability from ambient light are required. In general, different surfaces and different methods of marking also require different types of lighting in order to achieve a reliable reading. Conventional code reading devices preferably use lighting devices which are attached in the vicinity of the image recording unit, the lighting devices preferably emitting diffuse light.

The arrangement of one or more light sources in the vicinity of the recording unit is structurally relatively easy to implement and leads overall to a compact reading device. However, a reader that uses frontal diffuse lighting places high demands on the nature of the coded area and the quality of the marking. In particular, the surface of the coded surface must be such that it diffusely reflects the incident light and the components of the marking which contain the information of the code must differ significantly in terms of their reflectivity. Only under these conditions is it ensured that the image recorded by the image recording unit reflects the code with sufficient clarity and that the individual elements of the code can be distinguished by the computing unit. If, for example, the individual code elements of the marking differ only insufficiently from one another in terms of their reflectivity and from the code background, reading using frontal lighting becomes very difficult or even impossible. The same applies if the marking is applied, for example, to a reflective surface. In this case, the image recording unit and the lighting device can be reflected in the area of the marking on the coded surface, making correct reading of the code impossible. It has been shown that a reader constructed in this way is largely suitable for reading codes with high contrast on diffusely reflecting surfaces. In particular, codes applied to matt paper by means of a laser printer or an inkjet printer can generally be read with such a device. However, reading low-contrast codes or reading codes on reflective surfaces generally presents difficulties for a device constructed in this way.

Such problematic cases exist particularly in the case of the directly marked codes preferred in the industrial environment. With direct marking, the material and the nature of the coded area can no longer be freely selected, but are largely determined by the conditions of the object to be marked. The choice of a marking method is generally also restricted by a wide variety of boundary conditions. A marking should be able to be carried out as inexpensively as possible, the function of the objects to be marked must not be impaired by the marking, and any existing requirements for the durability of the marking must be met. For example, indirect marking by means of labels as well as marking with ink is usually not possible for the permanent marking of a metallic object, because the required durability cannot be achieved. If the object has to absorb mechanical forces, laser marking is not always permissible for safety reasons. For these reasons, the markings are often engraved, etched or pressed.

Engraved, etched or printed codes are often characterized by the fact that the associated surface changes only slightly change the reflectivity of the coded area. The result is a low-contrast marking, that is to say a marking in which the coded area has only a slight contrast between the light-dark areas, which is why such a code can be read only with difficulty or simply not with a conventional reading device.

There are now mobile readers that have a spacer that significantly simplifies reading a code. Here, the spacer has a length which positions the image recording unit of the reading device at a defined distance from the code to be read, so that the code to be read lies in the focus area of the image recording unit of the reading device. As a result, the positioning of the reading device relative to a code to be read in is considerably simplified since a complex leveling of the reading device relative to the code is superfluous. However, such reading devices also have the disadvantage that the lighting devices are arranged in the vicinity of the image recording unit, so that the code is only illuminated parallel to the image recording axis of the image recording unit. The invention is therefore based on the object of further developing a reading device such that reading a code, regardless of the method by which the code is implemented on an object, in particular an engraved, printed or etched code, and / or regardless of how the surface is of the item is guaranteed.

In terms of the device, the object is achieved by a reading device with an image recording unit for reading a code, in particular for reading a bar code, a two-dimensional code, a three-dimensional code or a color code, a spacer between the image recording unit and the code having at least one lighting device which has the code preferably illuminated from the side.

A lighting device is preferably to be understood as a component which is equipped with active luminous bodies and which actively emits light.

It goes without saying that with the reading device according to the invention any information-bearing marking can be read which is suitable for “reading” by means of machine vision. In particular, this also includes reading a so-called plain text marking (OCR writing). The reading device is also suitable not only for reading a bar code, a two-dimensional code, a three-dimensional code or a color code, but rather also a matrix code, plain text or any other marking which is suitable for providing an object with machine-readable information.

The reading device according to the invention is thereby enabled to adequately illuminate a code that is implemented, for example, by plastic deformation of the object surface, so that a reliable reading of the code is made possible. The side lighting illuminates the structuring elements of the code, which are embossed in the form of a surface change, so that even engraved, etched or printed codes can be read without problems. This lighting unit also allows a low-contrast code or even a code that would no longer have any contrast at all when viewed from the front.

A conventional reading device with a frontal diffuse illumination device is difficult to recognize depressions in the surface of an object and to distinguish them from a location in the surface of the object which has no recess. However, the lateral illumination device of the newly developed reading device makes it possible to illuminate an area coded, for example, with elevations and depressions, in such a way that a contrast-rich gray value change occurs, which is sufficiently recognized by a sensor of the reading device. With a conventional reading device, a code that is applied to a glossy or reflective surface cannot generally be read either. This is because the reflective areas of the coded area of a code recorded with a frontal lighting device do not stand out sufficiently from marked areas. The reflecting areas of the coded area produce an image of the lighting device and the image recording unit on the sensor. This image is neither uniformly light nor uniformly dark, which makes code reading significantly more difficult. In addition, reflections from the lighting device lead to very bright reflections. These reflections can be so strong that they exceed the dynamic range of the image recording unit and / or outshine the information-carrying code components on the sensor and thus make reading impossible.

In contrast, the reading device according to the invention is also able to adequately illuminate a code that is applied to a glossy or reflective surface, so that a reliable reading of the code is made possible. The light emitted by the side lighting is reflected by the reflecting surface at a flat angle and therefore does not reach the image recording unit. The reflective areas of the coded area on the light-sensitive sensor therefore appear dark and stand out clearly from the marked areas in the code, which in turn appear lighter on the sensor.

It is advantageous if the reading device also has an illumination unit which illuminates the code parallel to the optical image recording axis of an image recording unit of the reading device. It goes without saying that the lighting device of the spacer can also be used without a conventional lighting unit of the reading device.

It is possible that a conventional reading device is subsequently equipped with a spacer, which has a lighting device, so that it is not necessary to separate out an otherwise functioning reading device and to replace it with a new investment.

Another embodiment variant provides that the lighting device is arranged on the code-side end of the spacer. Conventional reading devices have a lighting device in the immediate vicinity of the image recording unit. As a result, many codes are not illuminated to a sufficient extent, so that a large number of codes cannot be read or can only be read inadequately. Because the lighting device is arranged at the code-side end of the spacer, it is possible to illuminate the code to be read rather from a radial direction - in relation to the image recording axis - than is the case with conventional reading devices. Is the lighting arranged at the code end of the spacer, it naturally has a greater proximity to the code to be read than to the image recording unit.

By means of the lighting unit according to the invention, the code to be read is not only illuminated from the front by diffuse light, but the code to be read is additionally or exclusively illuminated by light which strikes the code to be read from a radial direction. This leads to a significantly better differentiation of the marked areas with regard to the amount of light striking the sensor, in particular in the case of an engraved or stamped-in code, so that an object which is provided with such a marking variant is reliably identified.

It is particularly advantageous if the lighting device is designed as a ring light. The ring-shaped arrangement of the light-emitting elements leads to a largely homogeneous illumination of the coded area in the area of the field of view of the image recording unit. Due to the lateral illumination of the coded hache, the code reading performance of the reading device is significantly increased, with codes, for example, also being read without problems on a reflecting surface. Lasered codes can also be read much better thanks to the additional or exclusive side illumination.

If the lighting device is designed such that it illuminates the code to be read from all sides, for example, an unfavorable shadow formation is counteracted, as can occur, for example, when the coded surface is illuminated on one side.

It is further advantageous if the lighting device has at least one light-emitting diode (LED) as the lighting element. If a ring light is to be realized in this way, it is advantageous if this is done by stringing together a large number of light-emitting diodes. The use of at least one light-emitting diode has the advantage, for example, that a light-emitting diode has a very high luminance with a relatively small dimension. This is particularly advantageous since the lighting device should preferably be positioned directly in the vicinity of the coded area, and if the lighting device is too large, it can obstruct the view, since the user of the reading device has a view of the coded area due to a too large one Lighting device is difficult.

Another advantage that speaks for the use of at least one light-emitting diode arises when the light-emitting diode used emits monochrome light. This offers the possibility of reducing the influence of scattered light from the surroundings with appropriate design measures. For example, a filter can be attached to the lens of the recording unit, which has a high permeability for the monochrome light emitted by the LED. Light that does not correspond to the monochrome light of the light emitting diode is prevented by the filter up to the lens to reach the recording unit and is thus not even registered by the recording sensor. For example, red light-emitting diodes are used to illuminate the coded area, a red filter being arranged in front of the lens of the recording unit. Here, too, an increase in the code reading rate can be achieved, so that a time-consuming code reading repetition is eliminated. Another embodiment variant provides that the lighting device has lighting bodies of different luminous colors.

According to the invention, it is proposed that the lighting device has at least one lighting fixture, the lighting fixture preferably emitting monochrome light.

It goes without saying that any other technical light source can also be used for illuminating the coded area if this brings about advantages in relation to the legibility of a code.

Lighting fixtures of different luminous colors are particularly advantageous when reading color codes. Even when using an image recording unit that can only record differences in brightness but no differences in color, reading is possible by using colored light of different wavelengths. For example, the lighting unit has red-shining and green-shining lighting bodies, which can be switched individually controlled by the reading device. If the color code has, for example, green or red areas, these areas can be identified by the reading device on the basis of the projection which appears differently bright on the sensor depending on the type of lighting switched on. In this way, an originally color-blind reading device is enabled by the lighting device according to the invention to now also read color codes.

It is also advantageous if the spacer has a device in or on which an energy supply for the lighting device is arranged. Since the energy supply is preferably realized by a thin two-wire line, it is particularly important that this filigree energy supply of the lighting device is protected by a corresponding device. For example, the spacer has a pipe connection between the reading device and the lighting device, in which the energy supply is arranged. It is also possible for the spacer to have a groove in which a two-core cable is arranged, for example by means of a silicone paste.

A preferred embodiment variant provides that the lighting device has a connection to a computing unit of the reading device. The computing unit takes control of the lighting device, so that the lighting device interacts optimally with the recording unit. The connection of the lighting device can also be wired, the wired connection being arranged in the device of the spacer in which the energy supply drove the lighting device is arranged. It is also possible for the lighting unit to have a wireless connection to the computing unit.

The dimensions of the spacer are basically arbitrary. However, the length of the spacer to be selected depends on the properties of the receiving unit. It is particularly advantageous if the length of the spacer is selected such that the marking is in the focus area of the image recording unit when the code-side end of the spacer is on the coded surface or at a short distance in front of the coded surface. At the code-side end, the inner diameter of the spacer is selected such that the field of view of the receiving unit is not or only slightly impaired by the spacer.

A preferred embodiment variant therefore provides that the spacer has a length dimension of less than 150 mm, preferably a length dimension between 50 mm and 100 mm. In this way it is ensured that the reading device is brought at a favorable distance from the coded area for the reading. It is advantageous here if the length of the spacer is designed in such a way that the reader is in a focus area of the recording unit when the spacer lies on the coded surface. It has been found that a reading distance of 50 mm to 100 mm is favorable for reading markings typically used.

It is particularly advantageous if the inner diameter of the spacer is dimensioned such that the field of view of the camera is not or only slightly impaired by the spacer itself. For this purpose, the spacer, preferably at the code-side end, advantageously has an inner diameter of more than 20 mm, preferably an inner diameter of more than 30 mm.

It is also advantageous if the spacer, preferably at the code-side end, has an inner diameter of less than 60 mm, preferably an inner diameter of less than 50 mm. This results in a compact design of the reading device and of the spacer. This in turn makes the handling of the reading device considerably easier, which is particularly advantageous when working with the reading device over a longer period of time.

It is also advantageous if the spacer is arranged such that it can be displaced relative to the reading device in the direction of its longitudinal axis, so that the spacer is triggered by movement in the direction of its longitudinal axis toward the reading device, for example by means of a pressure switch, so that the code is read , Here, the pressure switch is arranged, for example, between the spacer and the housing of the reading device, the spacer being moved in the direction of the reading device when being placed on a coded surface and actuating the pressure switch. The invention proposes that the spacer have a device for activating the image recording unit and / or the lighting device. This device is preferably arranged at the code-side end of the spacer. For example, the device comprises a pressure switch or a sensor, so that the image recording unit and / or lighting unit are activated when there is contact with the coded surface or an approach to the coded surface.

It is particularly advantageous if the spacer has a protective ring at least at one end, preferably at the code-side end. Since the code-side end of the spacer is often in contact with the marked object, it is advantageous to protect this part of the spacer particularly against mechanical stress. Especially when the spacer is made of a plastic. This protective ring can serve, for example, as a flat contact surface of the code reading device on a coded surface. It is possible that the protective ring is a reinforcement of the spacer, in particular if the spacer is made from a wire frame.

According to a further embodiment variant, it is advantageous if the protective ring has a device which is suitable for activating the image recording unit and / or the lighting device. For example, a pressure switch or a sensor is arranged on the side facing the code surfaces, so that the image recording unit and / or the illumination device are activated when there is contact with the coded surface or when the coded surface is approached.

It is particularly advantageous if the lighting device is arranged in the vicinity of the protective ring. To protect the lighting device from mechanical stress, for example, and to avoid possible glare to the user from the lighting device, it is particularly advantageous to attach a protective ring to the code-side end of, for example, a transparent tube. It is advantageous if the size of the ring is selected such that the lighting device is covered by the protective ring and is thereby optimally protected.

According to a further preferred feature, the protective ring can have a light-absorbing material, preferably an opaque material. In this way, an otherwise possible glare to the user by the lighting device is avoided. It is also advantageous if the protective ring is designed in such a way that it prevents light radiation along the optical receiving axis to the receiving unit. For this purpose, the protective ring is designed, for example, in such a way that an area of the protective ring is arranged between the receiving unit and the lighting device.

It has been found that it is advantageous if the protective ring has means which prevent light radiation from at least one illumination device along the optical recording axis. Advantage- It is important if the protective ring is designed in such a way that it prevents light radiation along the optical recording axis towards the coded surface. For this purpose, the protective ring is designed, for example, in such a way that an area of the protective ring covers the code-side end of the transparent tube.

It is advantageous if at least two, preferably two mutually independent lighting units are arranged in the immediate vicinity of the image recording unit. These can interact with one another in such a way that they illuminate the code area particularly advantageously. For example, the lighting units alternately emit light, the lighting units additionally having, for example, lighting bodies of different colors. Here, the lighting units are each realized by an independent assembly, each with its own series of lighting fixtures. However, it is also possible for only a part of the lighting fixtures of a single lighting unit to be activated and for an alternating interaction with another part of the lighting fixtures of the same lighting unit. Thus, a second separate lighting unit does not actually exist, but is only simulated.

It has been found that it is advantageous if the lighting units have differently colored lighting bodies. This is particularly advantageous when a color code is to be read. Even when using an image recording unit which can only record differences in brightness but no differences in color, the use of colored light of different wavelengths enables the code to be read. For example, the lighting unit has red-shining and green-shining lighting bodies, which can be switched individually controlled by the reading device. If the color code has, for example, green and red areas, these areas could be reliably identified by the reading device on the basis of the projection which appears differently bright on the sensor depending on the type of lighting switched on. In this way, an originally color-blind reading device is enabled by the lighting device according to the invention to now also read color codes.

The different lighting units interact, for example, in such a way that the lighting units alternately emit light individually or in different combinations, the lighting unit additionally illuminating the code with lighting elements of different colors. It is particularly advantageous if the lighting devices are activated and controlled using an algorithmic method, preferably by the decoding unit of the reading device.

It goes without saying that the interaction described above also extends, for example, to the lighting unit at the code-side end of the spacer. It is further proposed according to the invention that the spacer is made narrower at least at one end, preferably at the code-side end. Due to the narrower design, the protective ring can advantageously be attached to the spacer, since the spacer at least partially accommodates the protective ring. For example, the spacer has a chamfer at the code-side end, which is designed in such a way that the protective ring can be arranged at least partially in the chamfer. This has the advantage that a much more intimate connection is made between the protective ring and the spacer.

It is particularly advantageous if the spacer comprises a transparent tube. The transparent tube, for example, offers excellent protection against contamination with respect to the image recording unit, but also against contamination of the lighting device. Likewise, the positioning of the reading device is considerably simplified by the arrangement of a transparent tube, since there is the possibility of looking through the tube, and thus the user can easily check the position of the reading device relative to the coded area and, if necessary, can easily correct the position ,

For example, the transparent tube has a protective ring to protect the code-side end, so that the tube is protected from wear. The protective ring is preferably made of a mechanically stronger material than the tube or it has an elastic surface.

A further embodiment variant provides that at least a part of the transparent tube is colored. This is particularly advantageous if a disturbing influence of scattered light is to be reduced further. The tube can be colored, for example, by directly coloring a material. However, applying a different colored coating to the transparent tube or applying a film to the transparent tube can also cause the tube to be colored.

It is particularly advantageous if the coloring of the transparent tube ends shortly before the code-side end of the tube, so that positioning of the reading device is made easier for the user, since the view of the coded area is not restricted by the coloring of the transparent tube in this area ,

It is possible, for example, that red light-emitting diodes are used to illuminate the coded area, a red filter preferably being arranged in front of the camera lens and the transparent tube having a blue / green color. A further preferred embodiment variant provides that the reading device has a pistol shape with a head region and a grip region. This enables the reader to be held particularly comfortably and simply and to be positioned securely in relation to a coded area.

It is advantageous if the head region has a fastening means with which the spacer can be detachably and firmly arranged on the head region. Depending on the application, this makes it possible to quickly and easily replace a first spacer with another spacer.

It goes without saying that the fastening means can comprise any type of quick-release fasteners which enable quick and easy exchange of spacers. For example, the fastening means comprises a bayonet lock, a plug lock or a thread with which the spacer can be quickly attached to the head area.

In order to be able to implement the energy supply of a lighting device of a spacer in a structurally particularly simple manner, it is advantageous if the fastening means has an energy-conducting contact device which provides the energy supply for the lighting device of the spacer.

In addition, it is advantageous if a decoding device and / or an optical signal transmitter is arranged in the head region.

It goes without saying that, as already mentioned above, the decoding device can be operated externally outside the reading device, and the reading device is connected to the external decoding device by means of a suitable interface.

It is advantageous if the optical signal transmitter comprises a multi-colored light-emitting diode, a red-light-emitting diode indicating readiness for readers and a green-light-emitting diode indicating successful reading of a code.

Cumulatively or alternatively, it is advantageous if an acoustic signal transmitter is arranged in the head area or in the handle area. Using the acoustic signal transmitter, different operating states of the reading device can be displayed to a user.

The object according to the invention is also achieved by a transparent tube with an illumination device, the illumination device comprising a main illumination axis and the main illumination axis being at an angle to the longitudinal axis of the transparent tube. preferential the lighting device is arranged at one end of the transparent tube, so that it advantageously illuminates the immediate area in the vicinity of the transparent tube.

It is particularly advantageous if the angle has a value between 45 ° and 90 °, preferably a value of more than 85 °. Particularly when the angle of the main illumination axis is more than 85 °, the coded area is illuminated particularly favorably, since the coded area is essentially illuminated laterally.

A preferred embodiment variant of the transparent tube provides a means for fixing the transparent tube to a reading device for reading a code, in particular for reading a bar code, a two-dimensional code, a three-dimensional code or a color code. Fixing the transparent tube to the reader greatly simplifies the reading in of a code, since the transparent tube defines the distance between an image pickup unit of the reader and the code in such a way that the code is in the optimal focus range of the image pickup unit during a reading.

It goes without saying that the transparent tube can accumulate all the features described above in the text or can each have them individually.

On the other hand, the object of the invention is achieved by a method for reading a code, in particular for reading a bar code, a two-dimensional code, a three-dimensional code or a color code, by means of a reading device with an image recording unit, the code being illuminated at an angle to the image recording axis of the image recording unit becomes. Because the code is now illuminated radially from the side, a low-contrast coded area is illuminated so well that it can be read without problems using the recording unit of the reading device. This is particularly advantageous since, in particular, a hand-held reader that is used for mobile purposes must read in a large number of different types of markings. For example, a handheld reader can now be used without any problems to optimally illuminate a strongly shiny or reflective coded area, or it can be used to read a marking that is implemented on an object based on an engraved, etched, pressed or punched code ,

It is particularly advantageous here if the code is illuminated at an angle between 45 ° and 90 °, preferably at an angle of more than 85 °. With such an illumination of a code, an engraved or stamped-in code can be read particularly well, since the resulting lighter and darker areas of the engraved or punched-out code are emphasized particularly well for the image recording unit. It goes without saying that the method according to the invention can be used to read any information-bearing mark, the information of which can be “read” by means of machine vision. Such information-bearing markings are understood as code in the sense of the invention. This applies in particular to reading a so-called “ Plain writing "mark (OCR writing).

It is also advantageous if the lighting device is switched on and off algorithmically. This is particularly advantageous if the lighting mode is set in such a way that at least one frontal and at least one side lighting are alternately switched on and off in rapid succession. The image acquisition unit is alternately offered an image acquisition with frontal and side illumination, whereby the success of a correct reading is significantly increased even with a problematic marking.

Particularly in the case of a lighting method with a plurality of lighting devices, it is advantageous that different lighting modes can be set in order to achieve an optimal lighting adaptation to different applications. For example, the reading device according to the invention is operated in such a way that frontal lighting alone illuminates the code to be read, that lateral lighting only illuminates the code to be read or that the frontal lighting and the side lighting together illuminate the code to be read.

Ultimately, it is proposed that at least two lighting units of the reading device algorithmically emit light, preferably monochrome light. This procedure allows the code area to be illuminated to be advantageously illuminated, since the reader can choose between at least one further illumination mode for improved readability. It goes without saying that this method can also be used independently of the other method variants.

Further advantages, goals and properties of the present invention are described with reference to the following explanation of the attached drawing, in which an example of a code reading device according to the invention is shown schematically.

It shows

FIG. 1 shows a schematic side view of a reading device,

2A schematically shows an arrangement of a protective ring,

Figure 2B schematically shows an alternative arrangement of a protective ring FIG. 3 shows a perspective side view of a reading device,

FIG. 4 shows a perspective top view of a reading device,

5 and 6 show two schematic views from below of the reading device according to the invention in different perspectives,

7 shows a transparent tube in a perspective side view and

Figure 8 is a schematic plan view of an alternative reading device in the form of a reading gun.

1 shows a reading device 1, a decoding unit 2 and a PC 3. The reading device 1, the decoding unit 2 and the PC 3 are connected to one another with a control spiral 4 and 5, respectively. The reader includes fully, a cylindrical metal housing 6 and a Plexiglas ^® tubing 7, that is, a tube made of clear plastic. At the lower end of the Plexiglas ^® -Rohrs 7 is a guard ring 8 is arranged.

An image recording unit 9 and two frontal lighting units 10 and 11 are located in the metal housing 6. The two frontal lighting units 10 and 11 are connected to one another in such a way that they alternately emit monochrome light. Furthermore, the cylindrical metal housing 6 has a trigger 12 on its outer surface and an interface 13 to the decoding unit 2 on the upper end face.

Integrated into the protective ring 8 is a ring illumination 14, which consists of a large number of light-emitting diodes.

The reader 1 rests with its protective ring 8 on a coded surface 15 of an object.

Here, the distance between the image recording unit 9 and the coded surface 15 is fixed at 70 mm, so that the coded surface 15 lies in the focus area of the image recording unit 9. If the trigger 12 is actuated, the lighting units 10 and 11 and the ring lighting 14 according to the invention illuminate the coded area 15, so that the image recording unit 9 can record the code. The inside diameter of the Plexiglas ^® tube 7 and the protective ring 8 is dimensioned with a 32 mm diameter so that the field of view of the image recording unit 9 is not significantly restricted. Here, the field of view of the image recording unit 9 is designed in such a way that the code can be read on the coded surface 15 without hindrance. FIG. 2A shows part of the wall of the plexiglass tube 7, on the code-side end 16 of which the protective ring 8 is shown schematically in a cut-open. The protective ring 8 is shaped in such a way that it closes off the Plexiglas ^® tube 7 in the form of a flat plane and thus on the one hand protects the tube and on the other hand effectively prevents the ring illumination 14 from emitting light along the optical recording axis toward the coded surface. Furthermore, the ring lighting 14 is arranged within the protective ring 8. This case is arranged the illumination ring 14 is sheathed on the one of the guard ring 8 and on the other of the Plexiglas ^® pipe 7, so that the ring light 14 from contamination and damage protection. The image recording axis 17 of the image recording unit 9 is shown spaced apart from the ring illumination 14. The coded surface 15 is shown schematically perpendicular to the image recording axis 17.

The main illumination direction 14 'of the lighting device 14 is also shown, the main illumination direction 14' including an angle 17 'with the image recording axis 17. The lighting device 14 illuminates the code on the coded surface 15 from the side.

FIG. 2B also shows part of the wall of a Plexiglas ^® tube 7 ', on the code-side end 16' of which a protective ring 8 'is shown schematically in a cut-open. The protective ring 8 'is also shaped in such a way that it closes off the Plexiglas ^® tube 7' in the form of a flat plane and thus on the one hand protects the tube and on the other hand effectively prevents the ring illumination 14 from emitting light along the optical recording axis toward the coded surface. Furthermore, a ring illumination 14 "is arranged within the protective ring 8 '. The Plexiglas ^® tube 7' has a substantially smaller outer diameter in the area 16 '. This results in the fact that at the code side end 16' of the Plexiglas ^® tube 7 ' on the outer lateral surface a material recess along the surface of the Plexiglas ^® -Rohres 7 'is present. In this material recess of the protection ring 8' is connected to the ring illumination 14 "positioned at least partially. Is also positioned in this case the illumination ring 2 is "'7 and on the other of the Plexiglas ^® tubing' sheathed on the one of the guard ring 8, so that the lighting Ringbe- 14" in this case also from contamination and damage protection. Advantageously, in this arrangement, the light emitted by the illumination ring 14 "does not have to shine through the complete material thickness of the Plexiglas ^® tube 7 ', but only penetrates part of the Plexiglas ^® material 7'. The emitted light experiences less attenuation and / or less distraction by the Plexiglas ^® material. This results, among other things, from the fact that the light emitted by the lighting ring 14 "does not have to pass through the entire wall thickness of the Plexiglas ^® tube T. In addition, the guard ring 8 builds' with respect to its diameter narrower than a guard ring 8 which is arranged on the outer periphery of the Plexiglas ^® -Rohres. 7 The metal housing of the reader 1 shown in FIG. 3 has a cover 18 and a cover 19, with which the end faces of the metal housing 6 are delimited. A trigger 12 with which the reading of the code is triggered is placed on the lateral surface 20 of the metal housing 6. The interface 13 is arranged centrally on the cover 18, with the aid of which a connection is established between the reading device 1 and the decoding unit 2. On the lower side in the region of the lid 19, the Plexiglas ^® is - arranged pipe 7 of the reading unit 1. At the code end of the Plexiglas ^® tube 7 there is the protective ring 8, which receives the ring lighting 14. The ring lighting 14 consists of a plurality of light-emitting diodes arranged in a row. Furthermore, the Plexiglas ^® tube 7 has a groove 20 in which an energy supply runs from the barrel-shaped metal housing 6 to the ring lighting 14.

The barrel-shaped metal housing 6 shown in FIG. 4 has a cover 18. The cover 18 is connected to the metal housing 6 in a form-fitting manner by means of four screws 21, 22, 23 and 24. On the cover 18, two indicator lamps 25 and 26 are arranged, which visually indicate the status of the reading of the code. Here, the indicator lamp 25 indicates by emitting a red light that the code has not been read. The indicator lamp 26, however, signals with a green light that the code has been read. In the middle of the cover 18, the interface 13 is arranged, the interface 13 having on its sides two threaded sockets 27 and 28, with the aid of which a connecting plug can be positively connected to the interface 13 and thus to the entire reading device 1.

The lower portion of the reading device 1 shown in Figure 5 schematically shows the guard ring 7. 8 at the end of the Plexiglas ^® co- deseitigen -Rohres are clearly to recognize the individual light emitting diodes of the ring illumination 14 in the guard ring. 8 At the other end of the Plexiglas ^® tube 7, the lower cover 19 of the metal housing 6 can be seen. The cover 19 is screwed to the metal housing 6 with two screws 29 and 30. The frontal lighting unit 10 and 11, which is composed of a large number of light-emitting diodes, is located in the region of the cover 19. The camera lens 31 with the image recording unit 9 is arranged in the center of the metal housing.

The lower area of the reading device 1 shown in FIG. 6 shows the metal housing 6 and the Plexiglas ^® tube 7. The Plexiglas ^® tube 7 has a groove 20 in which the energy supply of the ring lighting 14 runs. The ring lighting 14 is arranged between the Plexiglas ^® tube 7 and the protective ring 8.

The Plexiglas ^® tubing shown in Figure 7 stands on a coded surface 32. At the lower end of the Plexiglas ^® -Rohres 21 is an illumination device 33, wherein the illumination device 33, a plurality of lighting fixtures 34 (exemplary for all other light emitting body is only a loading luminous body numbered). The lighting fixture 34 has a main illumination axis 35, which has an angle 36 to the longitudinal axis 37 of the Plexiglas ^® tube 31. The illuminating device 33 illuminates the code of the coded surface 32 laterally with its illuminating bodies 34.

At the other end of the Plexiglas ^® tube 31 there is a means 38 for fixing the Plexiglas ^® tube 31 to a reading device. The means 38 for fixing the Plexiglas ^® tube 31 has two tabs 39 and 40, which are used to adjust the Plexiglas ^® tube 31 on a reading device.

The reading gun 41 (FIG. 8) comprises a head area 42 and a grip area 43. The head area 42 of the reading gun 41 has an image recording unit 9 (see FIG. 1) in the form of a digital camera, a first illumination device 10 and 11 (see FIG. 1) for the front Illumination of the code, a decoder 44 and a multi-colored light-emitting diode 45.

By means of a plug-in connection 46, an annular light attachment 47 is fixedly but releasably arranged on the head region 42 of the reading gun 41.

The ring light attachment 47 comprises a ring light 48, which is arranged at the code end of the ring light attachment 47 and laterally illuminates a code to be read. The ring light attachment 47 is a transparent tube, which comprises a protective ring 47A at least at the code-side end.

In order to supply the illuminant 49 of the ring light 48 with energy, the plug connection 46 has a contact device 50. An electrical energy supply between the reading gun 41 and the exchangeable ring light attachment 47 is ensured by means of the contact device 50, so that the ring light 48 is supplied with energy quickly and safely in a structurally particularly simple manner.

The multi-colored light-emitting diode 45 is particularly suitable for indicating readiness for reading and for displaying a read code. For example, the multicolored light-emitting diode 45 lights up red when read is ready and, after reading a code, lights up green.

With such a simple plug connection 46, the ring light attachment 48 can be offered as an accessory in addition to the reading gun 41. For example, the reading gun 41 can thus be equipped with different ring light receptacles 47 depending on the application. The grip area 43 of the reading gun 41 enables a user to easily handle the reading gun 41 and has a switch 51 for triggering the reading gun 41. The switch 51 is advantageously located relatively high up on the grip area 43 close to the head area 42 and is ergonomically designed in such a way that a finger of a user can easily lie around the switch 51 for simple and convenient operation. In addition, the grip area 43 includes a beeper 52 with which an operating state of the reading gun 41 can be audibly displayed. In this exemplary embodiment, the beeper 52 is arranged laterally on the grip area 43. However, the beeper is preferably arranged in the rear area, which faces away from the switch 51.

Cumulatively or alternatively to the internal decoding unit 44, the reading gun 41 has a socket 53 for receiving a connecting plug 54 and a connecting cable 55.

By means of the connecting plug 54 and the connecting cable 55, the reading gun 43 is supplied with electrical energy and, if appropriate, the code read is output.

If an exemplary embodiment of a reading gun 41 does not include an internal decoding unit 44, a plug-in connection 54 transmits a read code to a remote decoding server 2 (see FIG. 1) for decoding.

Claims

claims:

1. Reading device (1) with an image recording unit (9) for reading a code, in particular for reading a bar code, a two-dimensional code, a three-dimensional code or a color code, characterized in that a spacer between the image recording unit (9) and the code at least has an illumination device (14; 33) which preferably illuminates the code from the side.

2. Reading device (1) according to claim 1, characterized in that the lighting device (14; 33) is arranged on the code-side end (16) of the spacer.

3. Reading device (1) according to one of claims 1 or 2, characterized in that the lighting device (14; 33) is designed as a ring light.

4. Reading device (1) according to one of claims 1 to 3, characterized in that the lighting device (14; 33) has at least one light-emitting diode (LED) as the lighting element.

5. Reading device (1) according to one of claims 1 to 4, characterized in that the lighting device (14; 33) has at least one lighting element, the lighting element preferably emitting monochrome light.

6. Reading device (1) according to one of claims 1 to 5, characterized in that the lighting device (14; 33) has lighting bodies of different luminous colors.

7. Reading device (1) according to one of claims 1 to 6, characterized in that the spacer has a device (20) in and / or on which an energy supply of the lighting device (14; 33) is arranged.

8. Reading device (1) according to one of claims 1 to 7, characterized in that the lighting device (14; 33) has a connection to a computing unit of the reading device (1).

9. Reading device (1) according to one of claims 1 to 8, characterized in that the spacer has a length dimension of less than 150 mm, preferably a length dimension between 50 mm and 100 mm.

10. Reading device (1) according to one of claims 1 to 9, characterized in that the spacer, preferably at the code-side end, has an inner diameter of more than 20 mm, preferably an inner diameter of more than 30 mm.

11. Reading device (1) according to one of claims 1 to 10, characterized in that the spacer, preferably at the code-side end, has an inner diameter of less than 60 mm, preferably an inner diameter of less than 50 mm.

12. Reading device (1) according to one of claims 1 to 11, characterized in that the spacer in the direction of its longitudinal axis is arranged relatively displaceable to the reading device (1).

13. Reading device (1) according to one of claims 1 to 12, characterized in that the spacer has a device for activating the image recording unit (9) and / or lighting device (10, 11; 14; 33).

14. Reader (1) according to one of claims 1 to 13, characterized in that the spacer has at least at one end, preferably at the code-side end (16), a protective ring (8, 8 ').

15. Reading device (1) according to claim 14, characterized in that the protective ring (8, 8 ') has a device for activating the image recording unit (9) and / or the lighting device (10, 11; 14; 33).

16. Reading device (1) according to one of claims 14 or 15, characterized in that the lighting device (14; 33) is arranged in the vicinity of the protective ring (8, 8 ').

17. Reading device (1) according to one of claims 14 to 16, characterized in that the protective ring (8, 8 ') has a light-absorbing material, preferably an opaque material.

18. Reader (1) according to one of claims 14 to 17, characterized in that the protective ring (8, 8 ') has a means which emits light at least one illumination device (14; 33) along the optical recording axis (17; 37) prevented.

19. Reading device (1) according to one of claims 1 to 18, characterized in that at least two, preferably two mutually independent lighting units (10, 11) are arranged in the immediate vicinity of the image recording unit (9).

20. Reading device (1) according to one of claims 1 to 19, characterized in that at least one lighting unit (10, 11) has differently colored lighting bodies.

21. Reading device (1) according to one of claims 1 to 20, characterized in that the spacer is narrower at least at one end, preferably at the code-side end (16).

22. Reading device (1) according to one of claims 1 to 21, characterized in that the spacer comprises a transparent tube (7; 31).

23. Reader (1) according to claim 22, characterized in that at least part of the transparent tube (7; 31) is colored.

24. Reading device (1) according to one of claims 1 to 23, characterized in that the reading device (1) has a pistol shape with a head region (42) and a grip region (43).

25. Reading device (1) according to claim 24, characterized in that the head region (42) has a fastening means (46) with which the spacer can be releasably arranged on the head region (42).

26. Reading device (1) according to claim 25, characterized in that the fastening means (46) has an energy-conducting contact device (50) which provides an energy supply for the lighting device (48) of the spacer.

27. Reader (1) according to one of claims 24 to 26, characterized in that a decoding device (44) and / or an optical signal transmitter (45) is arranged in the head region (42).

28. Reading device (1) according to one of claims 24 to 27, characterized in that an acoustic signal transmitter (52) is arranged in the head region (42) or in the grip region (43).

29. Transparent tube (7; 31) with an illumination device (14; 33), the illumination device (14; 33) comprising a main illumination axis (14 '; 35), characterized in that the main illumination axis (14'; 35) has an angle (17 '; 36) to the longitudinal axis (37) of the tube (7; 31).

30. Transparent tube (7; 31) according to claim 29, characterized in that the angle (14 '; 36) has a value between 45 ° and 90 °, preferably a value of more than 85 °.

31. Transparent tube (7; 31) according to one of claims 29 or 30, characterized by means (38) for fixing the transparent tube (7; 31) to a reading device (1) for reading a code, in particular for reading a bar code , a two-dimensional code, a three-dimensional code or a color code.

32. Method for reading a code, in particular for reading a bar code, a two-dimensional code, a three-dimensional code or a color code, by means of a reading device (1) with an image recording unit (9), characterized in that the code is at an angle (17 ' ; 36) to the image recording axis (17) of the image recording unit (9) is illuminated.

33. The method according to claim 32, characterized in that the code is illuminated at an angle (17 '; 36) between 45 ° and 90 °, preferably at an angle of more than 85 °.

34. The method according to any one of claims 32 or 33, characterized in that the lighting device (14; 33) is switched on and off algorithmically.

35. The method according to any one of claims 32 to 34, characterized in that at least two lighting units (10, 11) of the reading device (1) algorithmically emit light, preferably monochrome light.