Abstract:
An attachment for a smart phone includes a targeting optic system which, when the attachment is secured to the backside of the smart phone, receives illumination emitted by the white light source and directs the illumination towards the target area from a location that is not directly in front of the camera&#39;s image sensor. The attachment directs illumination from the white light source in a direction parallel to the backside of the smart phone to a distance farther away from the camera&#39;s image sensor than a distance between the white light source and the camera&#39;s image sensor, and from that distance farther away from the camera&#39;s image sensor, directs the illumination into the target area.

Description:
CLAIM OF PRIORITY 
     This application is a continuation of U.S. patent application Ser. No. 13/708,835, titled “AN ATTACHMENT INCLUDING A MIRROR THAT CHANGES AN OPTICAL PATH OF A CAMERA DEVICE,” filed Dec. 7, 2012, with inventors George Powell, Ryan Hoobler, Ming Lei, Garrett Russell and Mark Ashby, which is incorporated herein by reference as if fully set forth. 
    
    
     BACKGROUND 
     Smartphones (and other types of portable, hand-held computing devices, such as tablet computers) are in widespread use today, most often in connection with entertainment, communications and office productivity. Most smartphones include a camera. Therefore, with appropriate software, such smartphones can be used to read bar codes. However, smartphones typically have poor bar code reading capability. 
     SUMMARY 
     This patent specification relates generally to improving the bar code-reading capabilities of a smartphone, a tablet computer, or any other portable, hand-held computing device that comprises a camera (hereinafter, “camera device”). More specifically, this patent specification describes an attachment for a camera device. The attachment comprises at least one of a target generating mechanism, a proximity sensor, illumination that is optimized for bar code reading, optics that provide an alternative optical path to the camera device, and a supplementary lens system that is optimized for bar code reading. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A-1B  illustrate an example of a camera device attachment that includes a target generating mechanism. 
         FIGS. 2-4  illustrate various targeting patterns that may be projected by the target generating mechanism shown in  FIGS. 1A-1B . 
         FIGS. 5A-5B  illustrate an example of a camera device attachment that includes a proximity sensor. 
         FIG. 6  illustrates one way that a camera device may utilize distance information provided by the proximity sensor shown in  FIGS. 5A-5B . 
         FIG. 7  illustrates another way that a camera device may utilize distance information provided by the proximity sensor shown in  FIGS. 5A-5B . 
         FIGS. 8A-8B  illustrate an example of a camera device attachment that includes illumination that is optimized for bar code reading. 
         FIG. 9  illustrates another example of a camera device attachment that includes illumination that is optimized for bar code reading. 
         FIG. 10  illustrates an example of a camera device attachment that includes a mirror that changes the optical path to the camera device. 
         FIG. 11  illustrates an example of a camera device attachment that includes a supplementary lens system that is optimized for bar code reading. 
         FIG. 12  illustrates an example of a camera device attachment that automatically activates the components that improve the bar code reading capabilities of the camera device in response to a detectable signal provided by the camera device. 
     
    
    
     DETAILED DESCRIPTION 
     As used in this patent specification and the accompanying claims, the term “camera device” will be used to describe a portable, hand-held computing device that comprises a camera. As indicated above, one example of a camera device is a smartphone. Another example of a camera device is a tablet computer. 
     As used herein, the term “camera” refers to an apparatus for capturing digital images. A camera that is included in a digital computing device (such as a smartphone, tablet computer, etc.) typically comprises a lens and an image sensor. 
     This patent specification describes an attachment for a camera device. The attachment may include one or more components that improve the bar code reading capabilities of the camera device. For example, the attachment may include a target generating mechanism, a proximity sensor, illumination optimized for bar code reading, optics that change the optical path to the camera device, a supplementary lens system that is optimized for bar code reading, etc. 
     Target Generating Mechanism 
       FIGS. 1A-1B  illustrate an example of a camera device attachment  100  that includes a target generating mechanism. The target generating mechanism may be utilized to facilitate rapid and optimal positioning of a camera device  102  with respect to a bar code  104  that the camera device  102  is attempting to read. This is especially useful when the camera device  102  does not have a display, or the display is dimmed or turned off to conserve the battery power, or the display is difficult to be viewed when the device  102  is operated as a bar code reader. 
     The target generating mechanism may include multiple targeting structures  106   a ,  106   b . These targeting structures  106   a ,  106   b  may project non-parallel targeting beams  108   a ,  108   b , each of which form a point or a pattern on the target area  110 . The targeting structures  106   a ,  106   b  may be configured so that (1) at the optimal distance from the camera  112 , the targeting beams  108   a ,  108   b  converge so that the projected patterns and/or points meet at the center of the camera&#39;s field of view  114 , and (2) at any distance from the camera  112  other than the optimal distance, the projected patterns and/or points do not meet. Thus, when the camera device  102  is being used to read a bar code  104 , the user may move the camera device  102  until the projected patterns and/or points meet, indicating that the camera device  102  is at the optimal distance from the bar code  104  and that the bar code  104  is positioned within the center of the camera&#39;s field of view  114 . 
     The targeting structure  106   a  includes a light source  116   a , a prism  118   a , a collimating lens  120   a , and a pattern generating surface  122   a . The targeting structure  106   b  includes a light source  116   b , a prism  118   b , a collimating lens  120   b , and a pattern generating surface  122   b . The light sources  116   a ,  116   b  may be laser diodes, light-emitting diodes (LEDs), etc. 
     Each of the pattern generating surfaces  122   a ,  122   b  may be an interference pattern generating element or a diffractive element, such as a holographic element that may include one or more diffractive gratings. Alternatively, each of the pattern generating surfaces  122   a ,  122   b  may be a Fresnel type element that has been fabricated with the desired pattern in mind. 
       FIGS. 2-4  illustrate various targeting patterns that may be projected by the targeting structures  106   a ,  106   b . As shown in  FIG. 2 , one possible targeting pattern  224  that may be projected by the targeting structures  106   a ,  106   b  is a circle  226  with a dot  228  in the center. One targeting structure  106   a  may generate the circle  226 , while the other targeting structure  106   b  may generate the dot  228 . The targeting structures  106   a ,  106   b  may be configured so that when the camera device  102  is an optimal distance from the bar code  104 , the dot  228  is substantially in the center of the circle  226  to form the depicted pattern  224 . 
     As shown in  FIG. 3 , another possible targeting pattern  324  that may be projected by the targeting structures  106   a ,  106   b  is a cross comprising a horizontal bar  330  and a vertical bar  332 . One targeting structure  106   a  may generate the horizontal bar  330 , while the other targeting structure  106   b  may generate the vertical bar  332 . The targeting structures  106   a ,  106   b  may be configured so that when the camera device  102  is an optimal distance from the bar code  104 , the horizontal bar  330  and the vertical bar  332  intersect each other to form the depicted pattern  324 . 
     As shown in  FIG. 4 , another possible targeting pattern  424  that may be projected by the targeting structures  106   a ,  106   b  is a circle  434  comprising an X  436 . One targeting structure  106   a  may generate the circle  434 , while the other targeting structure  106   b  may generate the X  436 . The targeting structures  106   a ,  106   b  may be configured so that when the camera device  102  is an optimal distance from the bar code  104 , the circle  434  and the X  436  may intersect each other to form the depicted pattern  424 . 
     Another possible targeting pattern may include one or more bars. The bar(s) may be, for example, blue LED bar(s). The length of the bar(s) may approximately coincide with the width of the field of view of the camera device  102 . 
     Another possible targeting pattern may include multiple (e.g., two) circles. The circles may overlap at the optimal distance from the bar code  104 . 
     Proximity Sensor 
       FIGS. 5A-5B  illustrate an example of a camera device attachment  500  that includes a proximity sensor  538 . The proximity sensor  538  may determine the distance  540  between the camera  512  and a bar code  504  that the camera device  502  is attempting to read. The proximity sensor  538  may then provide information  542  about this distance  540  to the camera  512 . 
     The attachment  500  may include an interface  544  between the proximity sensor  538  and the camera  512 . The interface  544  may facilitate communication of the distance information  542  from the proximity sensor  538  to the camera  512  (e.g., to a control program  552  running on the camera  512 ). More specifically, the interface  544  may receive electrical signals  546  from the proximity sensor  538 . The electrical signals  546  may indicate the distance  540  between the camera  512  and the bar code  504  that the camera device  502  is attempting to read. The interface  544  may convert the electrical signals  546  into distance information  542  that is in a format that the camera  512  is capable of understanding. Alternatively, the electrical signals  546  from the proximity sensor  538  may be sent to the control program  552  using a connector supported by the camera device  502  or wirelessly. 
     The attachment  500  may also include circuitry  548  that sends control signals  550  to the camera  512 . The control signals  550  may cause the camera  512  to use the distance information  542  from the proximity sensor  538  to assist with focusing appropriately. 
     For example, referring to  FIG. 6 , the control signals  550  may cause the camera  512  to disable the camera&#39;s auto-focusing feature (step S 602 ) and set the camera&#39;s focus value based on the distance information  542  that is provided by the proximity sensor  538  (step S 604 ). 
     Alternatively, referring to  FIG. 7 , the control signals  550  may cause the camera  512  to temporarily disable the camera&#39;s auto-focusing feature (step S 702 ) and set the camera&#39;s focus value based on the distance information  542  that is provided by the proximity sensor  538  (step S 704 ). Then, the camera  512  may subsequently re-enable the camera&#39;s auto-focusing feature after the camera&#39;s focus value has been set based on the distance information  542  (step S 706 ). 
     Illumination Optimized for Bar Code Reading 
       FIGS. 8A-8B  illustrate an example of a camera device attachment  800  that includes illumination that is optimized for bar code reading. The attachment  800  may be used in connection with a camera device  802  that includes a light source  852  that provides white illumination. This light source  852  may be referred to herein as a white light source  852 . The camera device  802  may also include a lens  854 . 
     The attachment  800  may include one or more single-color light sources  856 . The single-color light sources  856  may be light-emitting diodes (LEDs). The single-color light sources  856  may provide red illumination (i.e., illumination having a wavelength of about 650 nm). 
     The attachment  800  may include circuitry  858  that activates and deactivates the single-color light sources  856 . This circuitry  858  may be referred to herein as activation/deactivation circuitry  858 . In addition, the attachment  800  may include circuitry  860  that detects when the white light source  852  of the camera device  802  is activated and when the white light source  852  of the camera device  802  is deactivated. This circuitry  860  may be referred to herein as illumination detection circuitry  860 . 
     The activation/deactivation circuitry  858  may activate the single-color light sources  856  in response to the white light source  852  of the camera device  802  being activated. Similarly, the activation/deactivation circuitry  858  may deactivate the single-color light sources  856  in response to the white light source  852  of the camera device  802  being deactivated. 
     For example, when the illumination detection circuitry  860  detects that the white light source  852  of the camera device  802  has been activated, the illumination detection circuitry  860  may send control signals  862  to the activation/deactivation circuitry  858  that cause the activation/deactivation circuitry  858  to activate the single-color light sources  856 . Conversely, when the illumination detection circuitry  860  detects that the white light source  852  of the camera device  802  has been deactivated, the illumination detection circuitry  860  may send control signals  862  to the activation/deactivation circuitry  858  that cause the activation/deactivation circuitry  858  to deactivate the single-color light sources  856 . 
       FIG. 9  illustrates another example of a camera device attachment  900  that includes illumination that is optimized for bar code reading. The camera device  902  includes a white light source  952 . The attachment  900  includes a light pipe  964  that redirects white illumination  966  provided by the white light source  952  of the camera device  902 . Single-color filters  968   a ,  968   b  (e.g., red filters) within the light pipe  964  filter the redirected white illumination  966 , so that single color illumination  970   a ,  970   b  (e.g., red illumination) is directed toward the target area  910 . 
     The light pipe  964  may be configured so that the single-color illumination  970   a ,  970   b  is offset from the camera&#39;s image sensor  972  in order to prevent glare. In other words, the single-color illumination  970   a ,  970   b  may be directed toward the target area  910  from locations that are not directly in front of the camera&#39;s image sensor  972 . 
     Optics that Change the Optical Path to the Camera Device 
     With many camera devices, the focusing lens for the image sensor is located on the back side of the camera device. Therefore, in order to attempt to read a bar code, the camera device must be positioned so that the back side of the camera device is aimed at the bar code. 
       FIG. 10  illustrates an example of a camera device attachment  1000  that includes a mirror  1074  that changes the optical path to the camera device  1002 . The attachment  1000  permits a user of the camera device  1002  to attempt to read a bar code  1004  by aiming the top side  1076  of the camera device  1002  at the bar code  1004 . Light  1078  is reflected from the bar code  1004  and redirected by the mirror  1074  toward the camera device&#39;s focusing lens  1054 , which focuses the reflected light  1078  onto the camera device&#39;s image sensor  1072 . 
     In the depicted example, the mirror  1074  is positioned so that the reflected light  1078  is redirected by 90°. Alternatively, however, the mirror  1074  may be positioned so that the reflected light  1078  is redirected by a different angle. 
     Supplementary Lens System Optimized for Bar Code Reading 
       FIG. 11  illustrates an example of a camera device attachment  1100  that includes a supplementary lens system that is optimized for bar code reading. 
     The supplementary lens system may include an aperture  1180 . The aperture  1180  limits the amount of light that reaches the camera&#39;s image sensor  1172 . This may improve the depth of field of the camera  1112 . With enhanced depth of field, the need for auto-focusing is reduced and decode response is improved. 
     The supplementary lens system may include a lens  1182  that is optimized for bar code reading. For example, the lens  1182  may minimize distortion. The lens  1128  can produce images having a relatively small field of view and a relatively large bar code element size, thus making it easier to read bar codes with small printing size (e.g., between 3 millimeters and 6 millimeters). 
     The supplementary lens system may include a single-color filter  1184  (e.g., a red filter). The filter  1184  may be positioned in front of the lens  1182  that is optimized for bar code reading. 
     Activation of Components that Improve Bar Code Reading Capabilities 
     As indicated above, this patent specification describes an attachment for a camera device, wherein the attachment includes one or more components that improve the bar code reading capabilities of the camera device. An attachment as described herein may be configured to automatically activate the components that improve the bar code reading capabilities of the camera device in response to a detectable signal provided by the camera device. This signal may include, for example, a recognizable illumination pattern of the camera device. 
     An example will be described in relation to  FIG. 12 , which illustrates an attachment  1200  for a camera device  1202 . The attachment  1200  may include one or more targeting structures  1204 . The targeting structure(s)  1204  may be similar to the targeting structures  106   a ,  106   b  shown in  FIG. 1B . The targeting structure(s)  1204  may produce targeting beams, which may be similar to the targeting beams  108   a ,  108   b  shown in  FIG. 1B . 
     The attachment  1200  may also include one or more illumination sources  1206 . The illumination source(s)  1206  may be similar to the single-color light sources  856  shown in  FIG. 8A . 
     The attachment  1200  may also include a photo-detector  1208 . The photo-detector  1208  may be an image sensor. 
     The camera device  1202  may include one or more white illumination sources  1210 . In addition, the camera device  1202  may include a bar code reading application  1212 . 
     The camera device  1202  may be used to attempt to read a bar code (such as the bar code  104  shown in  FIG. 1A ). The bar code reading application  1212  may receive user input to begin attempting to read the bar code. For example, the user may press a “scan” button that is displayed via a user interface  1214  of the camera device  1202 . In response, the white illumination source(s)  1210  of the camera device  1202  may be activated and deactivated in accordance with a pattern that is recognizable to the photo-detector  1208  in the attachment  1200 . For example, the white illumination source(s)  1210  of the camera device  1202  may be briefly turned on and then turned off again. 
     The photo-detector  1208  in the attachment  1200  may detect this pattern. In response, the targeting structure(s)  1204  and the illumination source(s)  1206  of the attachment  1200  may be activated for a defined time period  1216 . This time period  1216  may be configurable. During this time period  1216 , the user can aim the targeting beams at the bar code and use the camera device  1202  to attempt to read the bar code. 
     The attachment  1200  may include its own battery  1218  to power the photo-detector  1208 , the targeting structure(s)  1204  and the illumination source(s)  1206 . 
     Meaning of “Attachment” 
     As used throughout this patent specification and the accompanying claims, an “attachment” for a camera device may include just a single component that improves the bar code reading capabilities of the camera device. Alternatively, an attachment may include multiple components that improve the bar code reading capabilities of the camera device. In addition, an attachment for a camera device may provide additional functionality that is unrelated to improving the bar code reading capabilities of the camera device. 
     An attachment for a camera device may cover a relatively small portion of the camera device. Alternatively, an attachment for a camera device may be a protective case that covers a substantial portion of the camera device. 
     Potential Uses 
     Bar code verification is the process of measuring the print quality of a printed bar code to analyze how it will perform in different environments with different types of scanning equipment. The process of verification involves checking the visual aspects (for modulation, decodability and more) of printed bar codes against standards made by international organizations. 
     An attachment that improves the bar code reading capabilities of a camera device, as described herein, may enable a camera device to be used for bar code verification, print verification, and/or other types of verification, and/or for reading direct part marks. 
     For bar code print quality verification or general printing analysis, the attachment must provide fixed reading distance and ensure there is no distortion when capturing an image of the target to be verified. When the imaging distance is fixed, the camera device can be calibrated to remove lens distortion and establish a conversion factor between the number of pixels and the actual physical size. 
     For reading direct part marks, ambient lighting or LED lighting from the camera device is usually not suitable to create sufficient contrast for decoding the marks. A special lighting attachment that provides diffused on-axis illumination and/or low angle illumination is needed. 
     Anti-Microbial Housing 
     An attachment as described herein may include an anti-microbial housing, i.e., a housing that includes one or more additives (e.g., a silver iodide additive) that inhibit the growth of mold and bacteria on the surface of the housing. This type of housing may be beneficial if a camera device is going to be used in a medical environment. 
     Chemical-Resistant Housing 
     Camera devices are often made with a housing of amorphous plastics, such as polycarbonate/acrylonitrilebutadiene-styrene (PC/ABS). Housings made of PC/ABS contain a loosely packed structure which makes it easier for chemicals to penetrate the plastic. Repeated use of chemical cleansers (e.g., cleansers that include isopropyl alcohol) may damage such housings. However, the use of chemical cleansers may be important. For example, if a camera device is going to be used as a bar code reader in a medical environment, it is important to frequently disinfect the camera device in order to try to prevent or limit the spread of infection. 
     An attachment as described herein may include a housing that is designed to resist the harmful effects of chemical cleansers. Such a housing may be referred to as a “chemical-resistant” (or a “disinfectant-ready”) housing. A chemical-resistant housing may include one or more additives (e.g., silicone) that reduce the harmful effects of chemical cleansers. 
     The claims are not limited to the specific implementations described above. Various modifications, changes and variations may be made in the arrangement, operation and details of the implementations described herein without departing from the scope of the claims.