DE102016119510A1 - Learning portable optical character recognition systems and methods - Google Patents

Abstract

The invention relates to a hand-held scanner with integrated image processing software, which enables an OCR learning capability of the hand-held scanner. The handheld scanner may include a user interface through which a user may associate an image of a character with electronic data for the character. The user interface, along with a range finder, can also be used to manipulate variables that affect the quality of an image scan, thereby improving the quality of results for the image scan and / or decoding process. The handheld scanner may also resort to a font description file during the decoding process. The font description file can be created from a synthetic image file of a character. The synthetic image file can be created by interpreting a caption font file.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of the pending U.S. Patent Application No. 14 / 521,508, filed on Oct. 23, 2014, entitled "Trainable Handheld Optical Character Recognition Systems and Methods", which is a continuation application U.S. Patent Application No. 13 / 590,744, filed on August 21, 2012, now U.S. Patent No. 8,873,892 on October 28, 2014, entitled "Trainable Handheld Optical Character Recognition Systems and Methods", all of which are hereby incorporated by reference.

INFORMATION ON STATE-ENCOURAGED RESEARCH AND DEVELOPMENT

• Not applicable

BACKGROUND OF THE INVENTION

The present invention relates to image processing systems, and more particularly to a handheld scanner having an adaptive optical character recognition function.

For example, optical image processing systems that support optical character recognition (OCR) are used to read fonts and other symbols on packaging or articles. One of the most common of these image processing systems is the handheld scanner. OCR is generally considered to be an electronic transformation of scanned images of handwritten, typewritten, or printed text into machine-coded text. It is important that image processing systems achieve a good quality scan so that the image is electronically searched, more compactly stored, displayed on a computer-by-machine basis, and used in machine processes such as image processing. B. the applications machine translation, speech synthesis (text-to-speech) and text mining, can be used.

To improve scan results, some optical image processing systems use standardized machine readable fonts, such as: OCR-A and OCR-B, designed to increase the accuracy of the OCR process. The standardized font allowed far less complicated decoding of the font in an image because the image processing system knew the fonts it was trying to decode and the individual fonts of the fonts were easily distinguishable. For example, the number "zero" contains a dash to help distinguish between the letters "o" (lowercase) and "O" (uppercase). However, many image processing applications, especially those for which a handheld scanner is intended to scan an object or article, do not use standardized fonts.

Some modern OCR systems may be "taught" to recognize other fonts or symbols. However, the learning process is a complicated and time-consuming process where each font and / or symbol must be scanned and then manually linked to the desired electronic character or data set. The learning process involves the use of a computer on which a user can view scanned images and associate the image with the desired data. Once all the fonts or symbols are associated with the desired data, an electronic file with all the linkage data can be created and then transferred to the image processing system for use by the image processing system to enhance the results of a scan.

There are current handheld scanners that have limited OCR capabilities. However, these current handheld scanners require pre-configured machine-readable fonts, such as OCR-A and OCR-B. It is not possible to teach current handheld scanners to use different fonts or symbols because the handheld scanners lack the processing power and user interface to support the linking of fonts and symbols to the desired data. In addition, as with any image processing device, given the many variables that affect the quality of an image scan, it may be difficult to obtain high quality results for each image scan.

Systems and methods are needed that allow a handheld scanner to be taught alternative fonts and / or symbols. In addition, systems and methods are needed that can improve the quality of the results for each image scan by affecting the variables that affect the quality of an image scan.

BRIEF SUMMARY OF THE INVENTION

The present embodiments overcome the disadvantages of the prior art by using image processing software with a hand-held scanner to make the hand-held scanner more adaptive to OCR. In some embodiments, the handheld scanner may include a user interface for associating with a user an image of a character with electronic data to allow for the character. Together with a range finder, the user interface can also be used to influence variables that affect the quality of an image scan, thereby improving the quality of the results of an image scanning and / or decoding process. In other embodiments, the handheld scanner may resort to a font description file during the decoding process. In some embodiments, a font description file may be created from a synthetic image file of a character. The synthetic image file can be created by interpreting a caption font file. In other embodiments, the handheld scanner may resort to a font description file created by interpreting a caption font file.

Accordingly, some embodiments include a handheld scanner. The hand scanner includes a scanner subassembly. The scanner subassembly may include an image processing sensor, a processor coupled to the image processing sensor, and a memory coupled to the processor. A user interface may be coupled to the scanner subassembly, the user interface including an optical display for viewing a real time image of at least a portion of a character to be scanned, wherein the visual display includes an area of interest visible on the visual display that is for use by a user allow positioning of the handheld scanner for optimum XY position of the handheld scanner. Further, processor may be executable by the processor for digitally interpreting a caption font file for decoding a subsequent image of the character, the caption font file describing the character.

Other embodiments include a handheld scanner. The hand scanner includes a scanner subassembly. The scanner subassembly may include an image processing sensor, a processor coupled to the image processing sensor, and a memory coupled to the processor. A range finder may be coupled to the scanner subassembly which protrudes by a predetermined length from an end face of the scanner subassembly, the predetermined length being an optimum working distance for a scan, the range finder being substantially parallel to an optical axis of the vision sensor from the face of the scanner subassembly protrudes. Further, processor may be executable by the processor for digitally interpreting a caption font file for decoding a subsequent image of the character, the caption font file describing the character.

Still other embodiments include a handheld scanner. The hand scanner includes a scanner subassembly. The scanner subassembly may include an image processing sensor, a processor coupled to the image processing sensor, and a memory coupled to the processor. The scanner subassembly may be coupled to a user interface comprising an optical display for viewing a real time image of at least a portion of a character to be scanned, the optical display comprising an area of interest visible on the optical display for positioning a user of the handheld scanner for optimal XY position of the handheld scanner. A range finder may be coupled to the scanner subassembly which protrudes by a predetermined length from an end face of the scanner subassembly, the predetermined length being an optimum working distance for a scan, the range finder being substantially parallel to an optical axis of the vision sensor from the face of the scanner subassembly protrudes. Further, processor may be executable by the processor for digitally interpreting a caption font file for decoding a subsequent image of the character, the caption font file describing the character.

Consistent with the above, some embodiments include a method of scanning a character on an object. The method includes providing a handheld scanner that includes an image processing sensor, a processor coupled to the image processing sensor, a memory coupled to the processor, a user interface, and a rangefinder; activating an optical display on the user interface, wherein the visual display is for viewing a real-time image of at least a portion of the character; observing the optical display while moving the hand-held scanner so that the visual display displays the real-time image of at least a portion of the character; positioning the real-time image of at least a portion of the character proximate to or within an area of interest for alignment feedback visible on the optical display; positioning the hand-held scanner so that a distal end of the rangefinder touches the object or is substantially close to the object; and digitally executing the image processing software to interpret a caption font file and to decode a subsequent image of the character, where the label font file describes the character.

In some embodiments, the method may further comprise digitally executing the image processing software to digitally associate the label font file with desired electronic data and to create a font description file, wherein the font description file is usable for decoding the subsequent image of the character.

In some embodiments, the digital linking further includes using the user interface to associate the electronic image of the character with the desired electronic data.

In some embodiments, the method may further include digitally interpreting the caption font file to create a synthetic image file.

In some embodiments, the method may further include digitally linking the synthetic image file to the desired electronic data to create the font description file.

In some embodiments, the method may further include actuating a trigger on the handheld scanner to activate the optical display.

In some embodiments, the method may further include releasing a trigger on the handheld scanner to enable the scan of the character.

In some embodiments, the method may further include decoding the image of the character and displaying the decoded character on the display screen.

In some embodiments, the method may further include positioning the real-time image of the character proximate to or within a region of interest visible on the optical display; positioning the hand-held scanner so that a distal end of the rangefinder touches the object or is substantially close to the object; activating a second scan of the character to create a second electronic image of the character, accessing the font description file stored in the memory; and decoding the second electronic image of the character from this font description file.

In order to achieve the above and related objects, the invention then comprises the features described hereafter extensively. The following description and the annexed drawings set forth in detail certain explanatory aspects of the invention. However, these aspects point out only a few of the many ways in which the principles of the invention can be used. Other aspects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in connection with the drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

1 shows a schematic view of an embodiment of a hand-held scanner according to the present embodiments and shows an optional, usable for OCR functions computer;

2 shows a plan view of the in 1 shown hand scanner;

3 shows a perspective view of the in 1 shown hand scanner and shows the hand scanner in a position before scanning an object;

4 13 shows a view of a display screen of a hand-held scanner according to the present embodiments and shows a character on an object in a partial view with only a portion of the character in a region of interest;

5 shows a view of the in 4 display screen and now displays the character in full view, but still only a portion of the character is in the region of interest;

6 shows a view of the in 5 display screen and now displays the character in full view with the character in the region of interest;

7 shows a perspective view of the in 3 shown hand scanner, which is now with a predetermined distance between the object and the hand scanner in a scanning position;

8th and 9 show flowcharts of methods associated with the handheld scanner;

10 shows a flowchart of a method for creating a synthetic image file;

11 shows a schematic view of a font description file;

12 shows a flowchart of a method in connection with the training of a hand-held scanner; and

13 shows a method associated with decoding a scanned image from a font description file.

While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail herein. It is to be understood, however, that the description of particular embodiments herein is not intended to limit the invention to the specific forms disclosed. Rather, it is the intention to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

The various aspects of the present invention will now be described with reference to the accompanying drawings, wherein like reference numerals correspond to like elements in the several views. It should be understood, however, that the drawing and the ensuing detailed description are not intended to limit the claimed subject matter to the specific form disclosed. Rather, it is the intention to cover all modifications, equivalents and alternatives that fall within the spirit and scope of the claimed subject matter.

As used herein, the terms "component", "system", "device" and the like are intended to refer to either hardware, a combination of hardware and software, software or software in the art. The word "exemplary" as used herein means that something serves as an example, case or illustration. Any aspects or embodiments described herein as "exemplary" are not necessarily to be considered preferred or advantageous over other aspects or embodiments.

Furthermore, the disclosed subject matter may be employed as a system, method, device, or article of manufacture using standard programming and / or engineering techniques and / or programming to produce hardware, firmware, software, or any combination thereof for controlling an electronics-based device to realize aspects described herein.

Unless otherwise specified or limited, the terms "connected" and "coupled" and the like are used in a broad sense and include both direct and indirect fasteners, connections, brackets and couplings. Furthermore, "connected" and "coupled" are not limited to physical and mechanical connections or couplings. As used herein, and unless expressly stated otherwise, "connected" means that one element / feature is directly or indirectly and not necessarily electrically or mechanically connected to another element / feature. Likewise, unless expressly stated otherwise, "coupled" means that an element / feature is directly or indirectly and not necessarily electrically or mechanically coupled to another element / feature.

As used herein, the term "processor" includes one or more processors and memory and / or one or more programmable hardware elements. As used herein, the term "processor" is intended to encompass any type of processors, CPUs, microcontrollers, digital signal processors, or other devices capable of executing software instructions.

As used herein, the term "storage medium" includes a non-volatile medium, e.g. A magnetic medium or a hard disk, optical memory or flash memory; a volatile medium, such as a system memory, e.g. B. Random Access Memory (RAM) such as DRAM, SRAM, EDO RAM, RAMBUS RAM, DR DRAM, etc .; or an installation medium, such as a software medium, e.g. As CD-ROM, or floppy disks on which programs stored and / or data communications can be buffered. The term "storage medium" may also include other types of storage and combinations thereof.

Embodiments of the invention are described below by means of diagrams to illustrate either the structure or operation of embodiments used to implement the embodiments of the present invention. Such use of the diagrams to illustrate embodiments of the invention should not be construed as limiting its scope. The present invention contemplates both electronic device configuration and systems and methods for teaching a portable optical character recognition system.

The various embodiments of an image processing system will be described in conjunction with a hand-held scanner that is adapted to perform OCR on custom and alternative fonts and other symbols. This is because the features and advantages of the invention are well suited for this purpose. It should be understood, however, that the various aspects of the invention may be applied in other types of image processing systems that would benefit from OCR functionality.

With reference to 1 Now, an exemplary embodiment in the context of a handheld scanner 20 described, inter alia, a scanner subassembly 22 , a user interface 24 and an optional rangefinder 26 includes. The exemplary hand scanner 20 can be used inter alia, as non-limiting examples, in warehousing, manufacturing, assembly, automation and / or in control applications. The exemplary hand scanner 20 can image acquisition software 30 used to perform any of various types of image capturing. The hand scanner 20 can perform machine vision tasks, including, as non-limiting examples, scanning and decoding images with fonts and / or symbols.

Further with reference to 1 can the scanner subassembly 22 include a variety of components used in the scanning process. For example, the scanner subassembly 22 an image processing sensor 32 include. The image processing sensor 32 is used by an object 34 and a corresponding sign 38 (Shown as stylized S) to transform light reflected on the object into electrons to form an electronic image 48 of the sign 38 in a field of view (FOV) 36 to create when a trigger 40 is pressed or released. In some embodiments, a lens assembly 42 above or in front of the image sensor 32 be arranged to the image sensor 32 a view of the object 34 in the FOV 36 to provide.

The scanner subassembly 22 can also have a processor 44 which is used, for example, for processing and decoding images. The processor 44 is to the image processing sensor 32 coupled and can either be part of the image processing sensor 32 or locally with the image processing sensor 32 be connected. The processor 44 can with the image acquisition software 30 Among other things, it may be configured to control the lighting, to capture image data, and to process / decode the captured image data into useable information. The processor 44 can also contact one or more visual feedback devices 46 and / or one or more audio feedback devices 50 be coupled to provide feedback to a user indicating the results of the scan and / or the decoding process (eg, whether the quality of the mapped character meets or exceeds a minimum quality assessment value or not). Visual feedback devices 46 For example, lights or LEDs 46 and the audio feedback device 50 can be a small speaker or a beep 50 include. In at least some cases, different LED colors may be used to indicate whether or not the character quality passes the minimum value test (eg, a green LED may indicate high character quality, while a red LED may indicate a character that failed a quality test Has).

The scanner subassembly 22 can also be a storage medium 52 include that to the image processing sensor 32 and / or to the processor 44 is coupled. The storage medium can be used to scan or process images 48 , Font description files 58 , Label font files 170 and buffer data and communications and the like. Also, a communication port 54 to the processor 44 coupled and as a connection point to an optional computer 56 serve. The computer 56 can be used, for example, for scanned or processed images 48 , Font description files 58 and caption font files 170 upload and download. It should be recognized that wireless communication is also conceivable.

Regarding 1 and also on 2 can the hand scanner 20 also a user interface 24 to allow a user to influence the quality of the results of a scan. In some embodiments, the user interface may include a small mobile data terminal or similar device running, for example, the Microsoft Windows CE operating system.

The user interface 24 can display a screen 60 and a keyboard 62 and may be an integral component of the scanner subassembly 22 or a detachable device that is functional to the scanner subassembly 22 can couple. In some embodiments, the display screen may 60 have a touchscreen function, reducing the number of keys to the keyboard 62 belong, be dropped or reduced. The display screen 60 make one Real-time feedback View 64 its ready, which is reflected in at least one section of the FOV 36 of the handheld scanner 20 located.

The exemplary display screen 60 may be a bordered or otherwise on the display screen 60 user-visible area of interest (ROI = region of interest) 66 include. The real-time feedback view 64 and the ROI 66 allow a user to manually manipulate at least one image processing variable and thus improve the quality of the results of a scan by allowing the user to basically see a real-time image of what the image processing sensor is 32 in the FOV 36 sees, and the hand scanner 20 reposition that to the desired character 38 within the ROI 66 is optimally positioned for a scan. The real-time feedback view 64 can be activated, for example, when the trigger 40 is pressed, or if necessary, the real-time feedback view 64 be activated when the hand scanner 20 switched on and ready to scan.

Regarding 3 a user would use the handheld scanner 20 at a certain distance to the object 34 and the associated character to be scanned 38 position. In some embodiments, the user would then trigger 40 Press to bring it to the display screen 60 to enable the real-time feedback view 64 display. The ROI 66 can basically be permanent on the display screen 60 to be seen, for example in the form of an overlay, or the ROI 66 can be a customizable image that can be adjusted for height and width for specific applications, and works in concert with the real-time feedback view 64 on the display screen 60 are displayed. It should be understood that the ROI 66 no square must be as shown, but any indication on the display screen 60 that allows a user to use the handheld scanner 20 reposition to improve the quality of the results of a scan. For example, a circle, an "X", a dot, arrows or a combination of these may be used.

In 4 Fig. 10 is an exemplary view of a display screen 60 shown in which is the sign 38 partly in the FOV 36 of the image processing sensor 32 and thus partially on the display screen 60 is shown. Because the user only part of the character 38 in the display, he can then see the position of the handheld scanner 20 adjust to try the handheld scanner 20 (or the character 38 ) to reposition that character 38 in the ROI 66 located. 5 shows an example where the character 38 in the FOV 36 and partly in the ROI 66 located. In some embodiments, the character could 38 be scanned at this point. To improve the quality of the results of the scan, the user could use the handheld scanner 20 (or the character 38 ) reposition, so that the character 38 essentially or completely in the ROI 66 located. 6 shows a view of the display screen 60 in which is the sign 38 completely in the ROI 66 located.

In some embodiments, the visual feedback device 46 and / or the audio feedback device 50 be used to give feedback to a user that is a position of the character 38 indicates, for. B. that the character is partially or completely in the ROI.

Regarding 7 may be an embodiment of the handheld scanner 20 a rangefinder 26 include. The rangefinder 26 can be used alone or in combination with the display screen 60 and the associated ROI 66 also serve to improve the quality of the results of the scan. When using a traditional handheld scanner, the physical position of the object is used 34 and the associated sign 38 In relation to the hand-held scanner, of course, an uncertainty is introduced into a character scan. The display screen 60 and the associated ROI 66 improve the XY position of the handheld scanner 20 and / or the sign 38 and provide some improvement in the Z position or working distance while using the range finder 26 the hand scanner 20 can be positioned at an optimal working distance and scale, while improving the XY position.

In embodiments with the rangefinder 26 Results of a scan can be improved provided the handheld scanner 20 by a given optimal distance 72 from the object 34 and the associated character to be scanned 38 is removed, so that the picture is basically in focus without the processor 44 in trying to get the sharpness of the character 38 to improve, to perform extensive calculations. The optimum working distance is important to determine the scale of the character in the image and to ensure sufficient image sharpness. In other embodiments, the lens assembly 42 a constantly focused or "zoom" lens assembly 42 which can be used to ensure a constant magnification for a wide range of working distances.

In the embodiment shown, the rangefinder comprises 26 a variety of fingers 86 coming from a base 90 protrude (s. 2 ). In this configuration, the character can 38 remain visible to a user who has the character 38 on the object 34 considered. In other embodiments can the rangefinder 26 a rather tubular or rectangular shape without those of the fingers 86 have formed gaps, allowing the possibility for the user, the actual character 38 on the object 34 to see, partially or significantly restricted.

As in 7 shown, the rangefinder 26 from a frontal face 74 of the handheld scanner 20 protrude. The rangefinder 26 may be a rigid element that extends along a line substantially parallel to an unillustrated central line of sight of the FOV 36 runs. In operation, a user can use the handheld scanner 20 position it so that a distal end 76 of the rangefinder 26 with a first character to be read 38 adjoining surface 80 of the object 34 comes into contact before the hand scanner 20 is activated. Here is the length 82 of the rangefinder 26 (S. 2 ) is designed so that the optimum imaging distance 72 between the hand scanner 20 and the first surface 80 is reached when the distal end 76 with the first surface 80 comes into contact. Thus, the rangefinder 26 in at least some embodiments also help to eliminate or reduce at least one image processing variable.

Still referring to 7 can the rangefinder 26 although he is here as rigid and in one piece with the handheld scanner 20 formed, for example, be flexible in some embodiments, as a radio antenna be telescopic and fold into a storage position. In some embodiments, the rangefinder may 26 be removable. So can the rangefinder 26 on the frontal face 74 by means of a clip or federal 84 or the like attached to the frontal end face 74 of the handheld scanner 20 coupled. The rangefinder 26 can also be made of a diffusive material, which is controlled by the handheld scanner 20 available lighting options are exploited. The light from the hand scanner 20 can then traverse the diffusive material and provide additional diffuse illumination benefits to improve the quality of the results of a scan.

In some embodiments, in combination with the rangefinder 26 or instead of the rangefinder (s. 2 ) a measuring device 92 includes, such as a known LED or laser diode 92 for distance measurements. The laser diode 92 may coincide with the display screen 60 work to provide an ad when an optimal working distance has been reached. The measuring device 92 can act as a range finder, for example as a TOF (Time of Flight) laser rangefinder. The measuring device 92 Can be used to remove the character 38 , which is used for the instruction, and the removal of the sign 38 to determine which is used for scanning. Scale differences between the teach and scan configurations could then be known and the magnification compensated for by standard machine vision techniques, such as image sizing or scale compensation in an OCR algorithm.

With renewed reference to 1 can the hand scanner 20 be instructed to perform OCR on custom and / or alternative fonts and other symbols. In this way, a user is able to control which fonts and symbols of the handheld scanner 20 can precisely scan and decode.

A problem with current handheld scanners is that they tend to scan standardized machine-readable fonts, such as a computer-readable font. As the known character sets OCR-A and OCR-B, limited and are not teachable for user requirements. These familiar fonts were designed to be easy to read and recognize. The current hand-held scanners can not read user-defined and alternative fonts and other symbols that can be printed using various printing techniques, such as dot matrix, thermal transfer, inkjet, and laser marking processes, and they can not read characters printed on consumer products. like on a bag of potato chips. These scanning applications are often associated with atypical reading conditions, including fluctuating lighting, varying depth of field, different printing methods, and different angle measurements. These circumstances present problems that are unresolved in current OCR-enabled handheld scanners. By integrating the display screen 60 and the rangefinder 26 in the teachable hand scanner 20 For recognizing fonts and symbols, these atypical reading circumstances are met.

To the hand scanner 20 To teach, in some embodiments, may be a computer 56 used to create a font description file 58 create a picture area associated with a character. The image area may be of any shape and may include a block of pixels that looks like a character, or, as a non-limiting example, any given shape, such as a box. B. have the letter S. The hand scanner 20 can be used to create an electronic picture 48 a letter, z. For example, of characters 38 to record. The picture 48 can on the computer 56 be downloaded, where an image processing software 96 , such as In-Sight ^® Explorer Cognex Corporation software that can be used to image 48 to associate with a font. Once the font description file 58 The font description file may be created 58 on the memory 52 in the hand scanner 20 getting charged. The hand scanner 20 can then be configured to use the font description file 58 to read, so the handheld scanner 20 to scan and decode the font.

In an alternative embodiment, the computer 54 omitted and the linking process and the creation of the font description file 58 on the hand scanner 20 respectively. The user interface 24 or the storage medium 52 can the image processing software 96 include and the keyboard 62 may have sufficient functions to perform the linking process.

8th . 9 and 12 illustrate embodiments of methods for using a handheld scanner 20 The in 8th . 9 and 12 The methods shown may be used inter alia in connection with any of the systems or devices shown in the above figures. In various embodiments, some of the method elements shown may be performed or omitted in accordance with or in a different order than that shown. Likewise, additional process elements can be performed as needed.

In 8th is a procedure 120 to scan a character 38 on an object 34 shown. A first step may be to use a handheld scanner 20 with a user interface 24 and a rangefinder 26 as in process block 122 shown. In the process block 124 a user can trigger 40 Press to see the visual indication 60 to activate. In process block 126 the user can then the visual display 60 watch while holding the handheld scanner 20 moved to the character 38 as close as possible to or in the ROI 66 to position. The user can use the handheld scanner 20 then in process block 130 position it so that the distal end 76 of the rangefinder 26 the first area 80 of the object 34 and the sign 38 touched or substantially close to it to establish the optimum working distance for the scan. It should be recognized that the handheld scanner 20 already in this optimal distance position can be. If the user the character 38 in the ROI 66 (S. 7 ) and the distal end 76 of the rangefinder 26 the object 34 touches, leaves the user in process block 132 the trigger 40 Go on to do the scan. Optionally, the processor 44 in process block 134 then decode the scanned image. As in process block 136 shown, the handheld scanner 20 optionally by activating one or more feedback devices 46 . 50 and / or by displaying the decoded image on the display screen 60 show the user a successful image scan and / or successful decoding. The method can then be repeated for the next character to be scanned.

In 9 is a procedure 150 to teach a handheld scanner 20 for OCR of a character 38 shown. A first step may be as in process block 152 shown a handheld scanner 20 with a memory 52 and a user interface 24 provide. In process block 154 can be a visual indicator 60 at the user interface 24 to be activated. The optical display 60 can be used to view a real-time image of the character 38 serve. In process block 156 the user can optically display 60 watch while holding the handheld scanner 20 so moved or positioned that the visual display 60 the real-time image of the character 38 displays. In process block 160 can be a scan of the character 38 be performed to create an electronic image of the character. The electronic image of the sign 38 can then be in memory 52 stored as in process block 162 displayed. In the next step, in process block 164 the electronic image of the sign 38 be linked to the desired electronic data. A font description file 58 can then be created, as in process block 166 shown linked the electronic image with the desired electronic data, and in process block 168 can be the font description file 58 In the storage room 52 get saved.

In other embodiments, the font description file may be 58 directly or indirectly from a label font file 170 to be created. The label font file 170 can be a software-based description 172 its how to print one or more fonts using a particular captioning technology. The font may, as non-limiting examples, include some or all of the alphanumeric characters (see characters 38 as an example of the stylized letter S) or other predetermined fonts.

As described above, there are many types of character labeling techniques, including dot matrix, thermal transfer, inkjet and laser marking, as non-limiting examples. There are many providers of label makers, including printers, who are able to label an item by one of these techniques. Some companies offer a wide range of products that use a variety of labeling techniques while other companies are specialized in a single labeling technique. Given the wide variety of labeling techniques and the many companies using these techniques, there are some format standards for a label font file in the lettering industry 170 ,

Some caption font files can map directly, such as a specific character 38 After printing, other caption font files do not map directly, such as the particular character 38 should look like after printing.

An example of a lettering technique that uses direct imaging is the thermal printing process, which can print at more than 600 dpi. The thermal printing technique often uses TrueType or another similar scalable label font file, and there are other known formats specific to vendors and label technologies. A label font file 170 for a thermal printing process, a software description may be the contours of the particular character 38 described mathematically, which can then be scaled and reproduced by a printer.

An example of a labeling technique that typically does not involve direct imaging is laser marking technology. In laser marking, characters can be created in one of several different ways. A labeling device, such as. For example, a laser printer using the laser marking technique may burn away an outer layer leaving the underlying layer visibly. The laser inscription can scorch a surface or surfaces with organic compounds, so that a contrast difference to surrounding areas arises. In laser marking also the material properties can be changed, such. B. by melting plastic or metal, which in turn a reflectivity is changed. A label font file 170 For laser marking, a software description may be like the laser, usually by controlling the tilt of a mirror to create the particular character 38 to be led. A simple caption font file 170 for the laser inscription can be the sign 38 for example, in the form of a series of laser strokes that can render the mark on a surface.

Another common labeling technique is the continuous ink jet method or CIJ (English: continuous ink-jet). CIJ printers shoot a steady stream of drops of ink. The ink droplets are electrically charged and the path of the charged droplets is changed by passing the charged droplets between plates with a regulated electrical charge. In order to form a particular character, the ink drops are usually applied in a single line whose position is determined by the electrical charge of the ink drops and the electrical charge of the plates. The second dimension of the character 38 created by the movement of the object, which is printed by the printer. A label font file 170 for the CIJ label may be a software description that defines a two-dimensional idealized grid of dots which is the ideal drop location for creating the particular character 38 represent. In reality, a CIJ label with slowly moving objects, such. B. a sheet of paper, very similar to this idealized grid. Faster moving objects create characters that may appear distorted relative to the idealized grid. Another effect is that the individual drops separate from one another rather than touching each other as the object moves farther away from the CIJ printer nozzle.

In some embodiments, the label font file may 170 be used by an OCR algorithm. The label font file 170 can also be digital in a format such. In the font description file 58 translated, which is usable by an OCR algorithm. In some embodiments, this can be done in a single step if operational details of the OCR algorithm and the format of the label font file 170 are known. In other embodiments, the label font file may 170 using an idealized synthetic image file 178 be translated as an intermediate step digitally into a format that is usable by an OCR algorithm. This intermediate step via the synthetic image file 178 may be necessary if the OCR file format is unknown, and because standard OCR algorithms allow the user to be instructed from forming, ie, to allow the user to specify the correspondence between the image area and the actual character. In other words, it becomes a synthetic image file 178 and then create an area of the image as a specific character 180 , such as B. identified as the stylized letter S.

Referring to 10 can be an interpretation algorithm 176 , the computer 56 or the processor 44 the label font file 170 digitally interpret to directly or indirectly the synthetic image file 178 create one or more characters, such. B. a special character 180 , like the stylized letter S of the sign 38 , or many characters, such as all alphanumeric characters. Of the interpretation algorithm 176 then knows that a certain character, z. B. the particular character 180 in a specific section of the caption font file 170 was reproduced. This information can then be sent to an OCR algorithm as input to the particular character 180 be passed on. The synthetic image file 178 may be an electronic data file which is an electronic data definition of an idealized character pattern of the particular character 180 provides. The synthetic image file 178 can then be used instead of or in conjunction with the one to create the font description file 58 used electronic picture 48 be used.

Because the caption font file 170 describes how a printer can print a particular character, such as a character 180 , each print will not necessarily have an electronic picture 48 a character to capture the image pixels of that character with the font description file 58 to match this character. No additional input or interaction may be needed to display a character in a captured image with the font description file 58 of the individual character. It may not be possible to create a so-called golden sample with high quality inscriptions for instruction purposes.

For training the hand scanner 20 can be the font description file 58 on the memory 52 in the hand scanner 20 getting charged. The hand scanner 20 can then be configured to display a picture, such as a picture. Eg picture 48 record and the font description file 58 read out, leaving the handheld scanner 20 the particular character, such as. B. Characters 180 , scan and decode.

In some embodiments, the label font file may 170 for example, from the computer 56 via the communication port 54 on the storage medium 52 downloaded and in the hand scanner 20 get saved. Becomes a synthetic image file 178 needed, because the OCR file format is unknown, the interpretation algorithm 176 the label font file 170 then interpret to directly or indirectly the synthetic image file 178 of the particular character 180 to create. The synthetic image file 178 can on the storage medium 52 saved or on the computer 56 be uploaded. Then the font description file can be 58 to create the synthetic image file 178 with a character 184 linked for use during the OCR process (see 11 ). This configuration may allow a better match between the ideal character and what is actually printed at run time because the label font file 170 may represent an improved description of the physical labeling process, which is then mapped by an OCR algorithm.

For example, a CIJ point separation and distortion can be measured and an OCR font more appropriate to the runtime properties can be created. In CIJ printing, individual drops may appear in the caption font file 170 This information may be described in performing the intermediate step of creating the synthetic image file 178 but can be lost. This information could be used by the OCR algorithm to better handle cases such as the drop / dot position increasing or decreasing due to the part position from the ink nozzle.

A second example is laser marking. As described above, the laser beam width can be influenced by both the laser power and the characteristics of the material to be labeled. Again, the OCR algorithm can better handle deviation from the ideal if this information is provided to the OCR algorithm, since the OCR algorithm is usually designed to use this type of information.

In other embodiments, the label font file may 170 on the computer 56 remain. The computer 56 can be the interpretation algorithm 176 Save and, if necessary, interpret the label font file 170 use to directly or indirectly the synthetic image file 178 of the particular character 180 to create. The synthetic image file 178 can on the computer 56 saved, or the synthetic image file 178 can on the storage medium 52 downloaded and in the hand scanner 20 get saved. The font description file 58 can then either on the computer 56 or on the handheld scanner 20 be created to the synthetic image file 178 of the particular character 180 with the character 184 for use during the OCR process.

Further features for the translation between the label font file 170 and the font description file 58 are explicitly conceivable. For example, it is not necessary for a caption font file 170 is used directly. Thus, an intermediate file format, such. B. a generic laser font description in the translation between the Beschriftungsschriftartdatei 170 and the font description file 58 be used.

For some caption font files 170 For example, the ideal label fonts may differ from run-time character properties. If character deviations are detected, further attributes of runtime characters, such as. B. a scale can be identified when recording the learning time and runtime images on the hand scanner 20 would not be necessary.

Referring to 12 is an alternative method 190 for the instruction of a hand scanner 20 for an OCR of a character 180 shown. A first step may be as in process block 192 shown a label font file 170 to interpret. Optionally, the label font file 170 by means of an interpretation algorithm 176 be interpreted. The interpretation algorithm 176 can as in process block 194 shown a synthetic image file 178 create. The synthetic image file 178 may be an electronic data definition of an idealized character pattern of a particular character, such. B. Characters 180 , provide. Optionally, the synthetic image file 178 in process block 198 to create the font description file 58 be used. In process block 200 can be the font description file 58 either on the computer 56 or on the storage medium 52 get saved.

Referring to 13 is a procedure 204 to scan a character 38 on an object 34 using a handheld scanner 20 shown. In process block 206 a user activates an image capture of the character 38 , In process block 208 can the processor 44 then try the scanned image by comparing the scanned image with a font description file 58 to decode. As in process block 210 hinted, the handheld scanner can 20 show successful image capture and / or decode by having one or more feedback devices 46 . 50 activated and / or the decoded image visible to the user on a display screen 60 displays. The method can then be repeated for the next image acquisition of a character.

Although the present invention has been described with reference to the preferred embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, the present invention is not limited to the embodiments of a hand-held scanner and associated devices set forth herein, and may be used in conjunction with other scanners and cameras.

The specific embodiments disclosed above are for descriptive purposes only, as the invention may be modified and implemented in various but equivalent manners which are obvious to those skilled in the art from the benefit of the teachings herein. Furthermore, no limitations other than those described in the claims below are intended with respect to the details of the construction and design shown herein. It is therefore to be understood that the specific embodiments disclosed above may be altered or modified, and all such changes are considered to fall within the scope and spirit of the invention. Accordingly, this application seeks protection as set out in the claims below.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 8873892 [0001]

Claims (22)

Hand scanner, comprising: a scanner subassembly comprising an image processing sensor, a processor coupled to the image processing sensor, and a memory coupled to the processor; a user interface coupled to the scanner subassembly, comprising an optical display for viewing a real time image of at least a portion of a character to be scanned, the optical display including an area of interest visible on the optical display for use by a user in positioning the handheld scanner to allow for optimal XY position of the hand scanner; and processor-executable image processing software configured to digitally interpret a caption font file to decode a subsequent image of the character, the caption font file describing the character. The handheld scanner of claim 1, wherein the image processing software is adapted to digitally associate the label font file with desired electronic data and to create a font description file, wherein the font description file is usable for decoding the subsequent image of the character. Hand scanner according to claim 1, wherein the inscription font file for creating a synthetic image file is digitally interpretable. The handheld scanner of claim 3, wherein the synthetic image file for creating the font description file is digitally connectable to the desired electronic data. The hand-held scanner of claim 1, wherein the hand-held scanner further comprises a range finder coupled to the scanner subassembly projecting from a face of the scanner subassembly by a predetermined length, the predetermined length representing an optimum working distance for a scan, the range finder being substantially parallel to one optical axis of the image processing sensor protrudes from the end face of the scanner subassembly. The handheld scanner of claim 1, wherein the user interface comprises a portable data terminal. The handheld scanner of claim 1, wherein the handheld scanner comprises at least one of a visual feedback device and an audio feedback device for providing feedback to a user indicating that the character is in the region of interest. The handheld scanner of claim 1, wherein the hand scanner on the scanner subassembly further comprises a light source for providing illumination, wherein the range finder comprises a diffusive material and the diffusive material of the range finder is penetrable by the light to provide diffuse illumination of the character. Hand scanner, comprising: a scanner subassembly comprising an image processing sensor, a processor coupled to the image processing sensor, and a memory coupled to the processor; a range finder coupled to the scanner subassembly projecting a predetermined length from an end face of the scanner subassembly, the predetermined length representing an optimum working distance for a scan, the range finder projecting substantially parallel to an optical axis of the vision sensor from the face of the scanner subassembly; and processor-executable image processing software configured to digitally interpret a caption font file to decode a subsequent image of the character, the caption font file describing the character. The handheld scanner of claim 9, wherein the image processing software is adapted to digitally associate the label font file with desired electronic data and to create a font description file, wherein the font description file is usable to decode the subsequent image of the character. Hand scanner according to claim 9, wherein the inscription font file for creating a synthetic image file is digitally interpretable. The handheld scanner of claim 11, wherein the synthetic image file for creating the font description file is digitally connectable to the desired electronic data. The handheld scanner of claim 9, wherein the handheld scanner further comprises a user interface coupled to the scanner subassembly and including an optical display for viewing a real time image of at least a portion of a character to be scanned, the optical display comprising a visible region of the optical display Interest, which serves to allow a user to position the hand-held scanner for an optimal XY position of the hand-held scanner. The hand-held scanner of claim 9, wherein the hand-held scanner further comprises a constant A focused lens assembly for providing a substantially constant magnification for a predetermined range of working distances comprises. The hand-held scanner of claim 9, wherein the hand-held scanner further comprises a measuring device for determining a distance to the character, wherein the processor uses the distance to the symbol for a scale determination. Hand scanner according to claim 9, the handheld scanner further comprising a computer coupled to the scanner subassembly, comprising image processing software configured to download the electronic image of the character, associate the electronic image of the character with desired electronic data, and create a font description file of the linked character; and wherein the computer is adapted to upload the font description file to the hand scanner subassembly, wherein the font description file is usable by the processor to decode a subsequent image of the character. Hand scanner, comprising: a scanner subassembly comprising an image processing sensor, a processor coupled to the image processing sensor, and a memory coupled to the processor; a user interface coupled to the scanner subassembly and including an optical display for viewing a real time image of at least a portion of a character to be scanned, the optical display including an area of interest visible on the optical display for positioning a user the hand-held scanner for optimal XY position of the hand-held scanner; a range finder coupled to the scanner subassembly projecting a predetermined length from an end face of the scanner subassembly, the predetermined length representing an optimum working distance for a scan, the range finder projecting substantially parallel to an optical axis of the vision sensor from the face of the scanner subassembly; and processor-executable image processing software configured to digitally interpret a caption font file to decode a subsequent image of the character, the caption font file describing the character. The handheld scanner of claim 17, wherein the image processing software is adapted to digitally associate the label font file with desired electronic data and to create a font description file usable for decoding the subsequent image of the character. The hand-held scanner of claim 17, wherein the label font file is digitally interpretable for creating a synthetic image file. The handheld scanner of claim 19, wherein the synthetic image file for creating the font description file is digitally associable with the desired data. The handheld scanner of claim 17, wherein the rangefinder comprises a plurality of fingers projecting from a base, the base being coupled to the hand scanner subassembly. A method of scanning a character on an object, the method comprising the steps of: Providing a handheld scanner comprising an image processing sensor, a processor coupled to the image processing sensor, a memory coupled to the processor, a user interface, and a rangefinder; Activating an optical display at the user interface, the visual display for viewing a real-time image of at least a portion of the character; Observing the optical display while moving the hand-held scanner so that the visual display displays the real-time image of at least a portion of the character; Positioning the real-time image of at least a portion of the character near or within an area of interest for alignment feedback visible on the optical display; Positioning the hand-held scanner so that a distal end of the rangefinder touches or is substantially close to the object; and digitally executing the image processing software to interpret a caption font file and to decode a subsequent image of the character, the caption font file describing the character.

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