PATENT DOCUMENT

Publication Number: US-8907935-B2
Application Number: US-201213620166-A
Country: US
Kind Code: B2

Title: Backlight calibration and control

Abstract:
A system and method for characterizing the power and luminance values for a display. This may include testing a device to determine a luminance value for a display of a given device at a given current and determining whether the first current is to be adjusted during future uses based on a comparison of the luminance with at least one threshold value. This may also include storing an adjusted current value if it is determined that the first current is to be adjusted.

Claims:
What is claimed is: 
     
       1. A method of manufacturing a display, comprising:
 driving a display at a first current; 
 measuring a display characteristic generated by the display while being driven at the first current; 
 determining whether the first current is to be adjusted based on a comparison of the measured display characteristic with at least one threshold value; and 
 storing an adjusted current value used to adjust the display characteristic only when it is determined that the first current is to be adjusted based upon the comparison. 
 
     
     
       2. The method of  claim 1 , wherein measuring the display characteristic comprises measuring a brightness of the display. 
     
     
       3. The method of  claim 2 , wherein measuring the brightness of the display is performed via an ambient light sensor physically located in a common enclosure with the display. 
     
     
       4. The method of  claim 2 , wherein measuring the brightness of the display is performed via a light sensor physically separate from the display. 
     
     
       5. The method of  claim 1 , wherein the comparison of the measured display characteristic with at least one threshold value comprises a comparison of a brightness of the display with a predetermined minimum brightness level for the display. 
     
     
       6. The method of  claim 5 , comprising generating the adjusted current value when it is determined that the brightness of the display is less than the predetermined minimum brightness level for the display. 
     
     
       7. The method of  claim 6 , comprising generating the adjusted current value as a lesser of a preset maximum current of the display and a function of the brightness of the display at the first current against the predetermined minimum brightness level for the display. 
     
     
       8. The method of  claim 1 , wherein the comparison of the measured display characteristic with at least one threshold value comprises a comparison of a brightness of the display with a predetermined maximum brightness level for the display. 
     
     
       9. The method of  claim 8 , comprising generating the adjusted current value when it is determined that the brightness of the display is greater than the predetermined maximum brightness level for the display. 
     
     
       10. The method of  claim 9 , comprising generating the adjusted current value as a greater of a preset minimum current of the display and a function of the brightness of the display at the first current against the predetermined maximum brightness level for the display. 
     
     
       11. The method of  claim 1 , comprising:
 driving a display at a second current; 
 measuring a second display characteristic generated by the display while being driven at the second current; 
 determining whether the second current is to be adjusted based on a comparison of the second measured display characteristic with at least one second threshold value; and 
 storing a second adjusted current value if it is determined that the second current is to be adjusted. 
 
     
     
       12. An electronic device, comprising:
 a display configured to display an image; and 
 a backlight calibration unit comprising:
 a processor configured to receive an indication of a display characteristic generated by the display while being driven at a first current and determine whether the display characteristic is to be adjusted based on a comparison of the indication of the display characteristic with at least one threshold value; and 
 a memory, wherein the memory is configured to store an adjusted current value used to adjust the display characteristic only when it is determined by the processor that the display characteristic is to be adjusted based upon the comparison. 
 
 
     
     
       13. The electronic device of  claim 12 , comprising an ambient light sensor configured to generate the indication of the display characteristic as a brightness level of the display. 
     
     
       14. The electronic device of  claim 12 , wherein the processor is configured to compare the indication of the display characteristic with a predetermined minimum brightness level for the display as the at least one threshold value. 
     
     
       15. The electronic device of  claim 14 , wherein the processor is configured to generate the adjusted current value as a lesser of a preset maximum current of the display and a function of a brightness of the display at the first current against the predetermined minimum brightness level for the display only when it is determined that the indication of the display characteristic is less than the predetermined minimum brightness level for the display. 
     
     
       16. The electronic device of  claim 12 , wherein the processor is configured to compare the indication of the display characteristic with a predetermined maximum brightness level for the display as the at least one threshold value. 
     
     
       17. The electronic device of  claim 16 , wherein the processor is configured to generate the adjusted current value as a greater of a preset maximum current of the display and a function of a brightness of the display at the first current against the predetermined maximum brightness level for the display only when it is determined that the indication of the display characteristic is greater than the predetermined maximum brightness level for the display. 
     
     
       18. The electronic device of  claim 12 , wherein the processor is configured to receive a second indication of a second display characteristic while being driven at a second current and determine whether the second display characteristic is to be adjusted based on a comparison of the second indication of the second display characteristic with at least one threshold value, wherein the memory is configured to store a second adjusted current value related to the second display characteristic if it is determined by the processor that the second display characteristic is to be adjusted. 
     
     
       19. An electronic device, comprising:
 a display configured to display an image; and 
 a backlight calibration unit comprising:
 a processor configured to receive an indication of the brightness of the display while being driven at a first current and determine whether the first current is to be adjusted based on a comparison of the indication of the brightness of the display with at least one threshold value; and 
 a memory, wherein the memory is configured to store an adjusted current used to adjust a display characteristic only when it is determined by the processor that the first current is to be adjusted based upon the comparison. 
 
 
     
     
       20. The electronic device of  claim 19 , comprising an ambient light sensor configured to generate the indication of the brightness of the display. 
     
     
       21. The electronic device of  claim 19 , wherein the processor is configured to compare the indication of the brightness of the display with a predetermined minimum brightness level for the display as the at least one threshold value. 
     
     
       22. The electronic device of  claim 21 , wherein the processor is configured to generate the adjusted current value as a lesser of a preset maximum current of the display and a function of the brightness of the display at the first current against the predetermined minimum brightness level for the display only when it is determined that the indication of the brightness of the display is less than the predetermined minimum brightness level for the display. 
     
     
       23. The electronic device of  claim 19 , wherein the processor is configured to compare the indication of the brightness of the display with a predetermined maximum brightness level for the display as the at least one threshold value. 
     
     
       24. The electronic device of  claim 23 , wherein the processor is configured to generate the adjusted current value as a greater of a preset maximum current of the display and a function of the brightness of the display at the first current against the predetermined maximum brightness level for the display only when it is determined that the indication of the brightness of the display is greater than the predetermined maximum brightness level for the display. 
     
     
       25. The electronic device of  claim 19 , wherein the processor is configured to receive a second indication of a second brightness of the display while being driven at a second current and determine whether the second current is to be adjusted based on a comparison of the second indication with at least one threshold value, wherein the memory is configured to store a second adjusted current value if it is determined by the processor that the second current is to be adjusted.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a Non-Provisional Patent Application of U.S. Provisional Patent Application No. 61/657,647, entitled “Backlight Calibration and Control”, filed Jun. 8, 2012, which is herein incorporated by reference. 
     BACKGROUND 
     The present disclosure relates generally to the operating parameters of an electronic device display. 
     This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     Visual displays are commonly used for a wide variety of electronic devices, including such consumer electronics as computers and handheld devices (e.g., cellular telephones, audio and video players, gaming systems, and so forth). Such displays typically provide a flat display using display circuitry in a relatively thin package that is suitable for use in a variety of electronic goods. 
     Often, the number of displays produced may exceed the manufacturing capability of one or more manufacturers. Therefore, it is common for electronic displays to include components from various manufacturers. A problem may arise due to a lack of uniformity of the components manufactured by the different suppliers. In other words, display components from different manufacturers may respond differently to similar signals even under similar conditions. Thus, if the displays do not incorporate techniques for adjusting to the variance in components, a display utilizing components from one manufacturer may appear to display an image in a substantially different manner than a display utilizing components from another manufacturer. Accordingly, there is a need for condition based controls for a display. 
     SUMMARY 
     A summary of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects that may not be set forth below. 
     Certain embodiments of the present disclosure are directed to production and testing of electronic displays. When large quantities of displays are manufactured, similar display components may have different responses to similar signals under similar conditions. This may arise from manufacturing tolerances or processes differing from one manufacturer to another. For example, display brightness may vary from one device to another. However, variation in the performance of devices may be perceived as a defect by users. Accordingly, the brightness of each manufactured device may be tested and a brightness offset value may be determined for displays that do not conform within general tolerance levels. This offset value may be saved and applied during operation of the device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various aspects of this disclosure may be better understood upon reading the following detailed description and upon reference to the drawings in which: 
         FIG. 1  is a block diagram of an electronic device in accordance with aspects of the present disclosure; 
         FIG. 2  is a perspective view of a cellular device in accordance with aspects of the present disclosure; 
         FIG. 3  is a perspective view of a handheld electronic device in accordance with aspects of the present disclosure; 
         FIG. 4  is an exploded view of a liquid crystal display (LCD) in accordance with aspects of the present disclosure; 
         FIG. 5  graphically depicts circuitry that may be found in the LCD of  FIG. 4  in accordance with aspects of the present disclosure; 
         FIG. 6  is a block diagram representative of how the LCD of  FIG. 4  receives data and drives a pixel array of the LCD in accordance with aspects of the present disclosure; 
         FIG. 7  includes graphical representations of brightness and current outputs for a set of devices of  FIG. 1  in accordance with aspects of the present disclosure; 
         FIG. 8  includes second graphical representations of brightness and current outputs for a set of devices of  FIG. 1  in accordance with aspects of the present disclosure; 
         FIG. 9  includes a graphical representations of a luminance curve for an LCD of  FIG. 2  or  3  in accordance with aspects of the present disclosure; 
         FIG. 10  includes a flow chart illustrating a method of generating the luminance curve of  FIG. 9  in accordance with aspects of the present disclosure; 
         FIG. 11  includes a flow chart illustrating a method of determining a calibration value for the device of claim  1  in accordance with aspects of the present disclosure; 
         FIG. 12  illustrates a block diagram illustrating the interaction between the display calibration unit of  FIG. 1  and the backlight unit of  FIG. 4  in accordance with aspects of the present disclosure; and 
         FIG. 13  illustrates a block diagram illustrating the interaction between the display calibration unit of  FIG. 1  and the backlight unit of  FIG. 4  in accordance with aspects of the present disclosure 
     
    
    
     DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS 
     One or more specific embodiments will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     Certain embodiments of the present disclosure are directed to production of electronic displays. When large quantities of displays are manufactured, the demand for components may not be met by one lot of components from a manufacturer or even by one manufacturer. Due to different manufacturing tolerances among manufacturers and varying quality of materials between manufactured lots, similar display components may have different responses to similar signals under similar conditions. For example, display brightness may vary from one device to another. Variation in display brightness may be perceived as a defect in a device. Accordingly, calculation of and application of a brightness offset on a device by device basis may be undertaken to reduce variance in brightness of displays between two electronic devices (i.e., allow for more uniform display characteristics to be achieved). Moreover, this brightness offset may also be utilized as one input for overall calibration of the backlight of the device. 
     As may be appreciated, electronic devices may include various internal and/or external components which contribute to the function of the device. For instance,  FIG. 1  is a block diagram illustrating components that may be present in one such electronic device  10 . Those of ordinary skill in the art will appreciate that the various functional blocks shown in  FIG. 1  may include hardware elements (including circuitry), software elements (including computer code stored on a computer-readable medium, such as a hard drive or system memory), or a combination of both hardware and software elements.  FIG. 1  is only one example of a particular implementation and is merely intended to illustrate the types of components that may be present in the electronic device  10 . For example, in the presently illustrated embodiment, these components may include a display  12 , input/output (I/O) ports  14 , input structures  16 , one or more processors  18 , one or more memory devices  20 , nonvolatile storage  22 , expansion card(s)  24 , networking device  26 , power source  28 , and a backlight calibration unit  30 . 
     The display  12  may be used to display various images generated by the electronic device  10 . The display  12  may be any suitable display, such as a liquid crystal display (LCD) or an organic light-emitting diode (OLED) display. Additionally, in certain embodiments of the electronic device  10 , the display  12  may be provided in conjunction with a touch-sensitive element, such as a touchscreen, that may be used as part of the control interface for the device  10 . 
     The I/O ports  14  may include ports configured to connect to a variety of external devices, such as a power source, headset or headphones, or other electronic devices (such as handheld devices and/or computers, printers, projectors, external displays, modems, docking stations, and so forth). The I/O ports  14  may support any interface type, such as a universal serial bus (USB) port, a video port, a serial connection port, an IEEE-1394 port, a speaker, an Ethernet or modem port, and/or an AC/DC power connection port. 
     The input structures  16  may include the various devices, circuitry, and pathways by which user input or feedback is provided to processor(s)  18 . Such input structures  16  may be configured to control a function of an electronic device  10 , applications running on the device  10 , and/or any interfaces or devices connected to or used by device  10 . For example, input structures  16  may allow a user to navigate a displayed user interface or application interface. Non-limiting examples of input structures  16  include buttons, sliders, switches, control pads, keys, knobs, scroll wheels, keyboards, mice, touchpads, microphones, and so forth. Additionally, in certain embodiments, one or more input structures  16  may be provided together with display  12 , such an in the case of a touchscreen, in which a touch sensitive mechanism is provided in conjunction with display  12 . 
     Processors  18  may provide the processing capability to execute the operating system, programs, user and application interfaces, and any other functions of the electronic device  10 . The processors  18  may include one or more microprocessors, such as one or more “general-purpose” microprocessors, one or more special-purpose microprocessors or ASICS, or some combination of such processing components. For example, the processors  18  may include one or more reduced instruction set (RISC) processors, as well as graphics processors, video processors, audio processors, and the like. As will be appreciated, the processors  18  may be communicatively coupled to one or more data buses or chipsets for transferring data and instructions between various components of the electronic device  10 . 
     Programs or instructions executed by processor(s)  18  may be stored in any suitable manufacture that includes one or more tangible, computer-readable media at least collectively storing the executed instructions or routines, such as, but not limited to, the memory devices and storage devices described below. Also, these programs (e.g., an operating system) encoded on such a computer program product may also include instructions that may be executed by the processors  18  to enable device  10  to provide various functionalities, including those described herein. 
     The instructions or data to be processed by the one or more processors  18  may be stored in a computer-readable medium, such as a memory  20 . The memory  20  may include a volatile memory, such as random access memory (RAM), and/or a non-volatile memory, such as read-only memory (ROM). The memory  20  may store a variety of information and may be used for various purposes. For example, the memory  20  may store firmware for electronic device  10  (such as basic input/output system (BIOS)), an operating system, and various other programs, applications, or routines that may be executed on electronic device  10 . In addition, the memory  20  may be used for buffering or caching during operation of the electronic device  10 . 
     The components of the device  10  may further include other forms of computer-readable media, such as non-volatile storage  22  for persistent storage of data and/or instructions. Non-volatile storage  22  may include, for example, flash memory, a hard drive, or any other optical, magnetic, and/or solid-state storage media. Non-volatile storage  22  may be used to store firmware, data files, software programs, wireless connection information, and any other suitable data. 
     The embodiment illustrated in  FIG. 1  may also include one or more card or expansion slots. The card slots may be configured to receive one or more expansion cards  24  that may be used to add functionality, such as additional memory, I/O functionality, or networking capability, to electronic device  10 . Such expansion cards  24  may connect to device  10  through any type of suitable connector, and may be accessed internally or external to the housing of electronic device  10 . For example, in one embodiment, expansion cards  24  may include a flash memory card, such as a SecureDigital (SD) card, mini- or microSD, CompactFlash card, Multimedia card (MMC), or the like. Additionally, expansion cards  24  may include one or more processor(s)  18  of the device  10 , such as a video graphics card having a GPU for facilitating graphical rendering by device  10 . 
     The components depicted in  FIG. 1  also include a network device  26 , such as a network controller or a network interface card (MC). In one embodiment, the network device  26  may be a wireless NIC providing wireless connectivity over any 802.11 standard or any other suitable wireless networking standard. The device  10  may also include a power source  28 . In one embodiment, the power source  28  may include one or more batteries, such as a lithium-ion polymer battery or other type of suitable battery. Additionally, the power source  28  may include AC power, such as provided by an electrical outlet, and electronic device  10  may be connected to the power source  28  via a power adapter. This power adapter may also be used to recharge one or more batteries of device  10 . 
     The electronic device  10  may also include a backlight calibration unit  30 . In one embodiment, the backlight calibration unit  30  may be used to determine and/or apply an offset value to the display to alter the current applied to LED strings in the display. As will be discussed in greater detail below, this offset value may allow for the electronic device  10  to display images at a particular brightness. 
     The electronic device  10  may take the form of a computer system or some other type of electronic device. Such computers may include computers that are generally portable (such as laptop, notebook, tablet, and handheld computers), as well as computers that are generally used in one place (such as conventional desktop computers, workstations and/or servers). In certain embodiments, electronic device  10  in the form of a computer may include a model of a MacBook®, MacBook® Pro, MacBook Air®, iMac®, Mac® mini, or Mac® Pro available from Apple Inc. of Cupertino, Calif. 
     The electronic device  10  may also take the form of other types of electronic devices. In some embodiments, various electronic devices  10  may include mobile telephones, media players, personal data organizers, handheld game platforms, cameras, and combinations of such devices. For instance, as generally depicted in  FIG. 2 , the device  10  may be provided in the form of a cellular device  32  (such as a model of an iPhone®), that includes various functionalities (such as the ability to take pictures, make telephone calls, access the Internet, communicate via email, record audio and video, listen to music, play games, and connect to wireless networks). Alternatively, as depicted in  FIG. 3 , the electronic device  10  may be provided in the form of a handheld electronic device  33 . By way of further example, handheld device  33  may be a model of an iPod® or iPad® available from Apple Inc. of Cupertino, Calif. 
     Electronic device  10  of the presently illustrated embodiment includes a display  12 , which may be in the form of an LCD  34 . The LCD  34  may display various images generated by electronic device  10 , such as a graphical user interface (GUI)  38  having one or more icons  40 . The device  36  may also include various I/O ports  14  to facilitate interaction with other devices, and user input structures  16  to facilitate interaction with a user, as well as an ambient light sensor  41  that includes one or more photosensors or photodetectors that sense light or other electromagnetic energy, such as ambient light surrounding the electronic device  10 . 
     One example of an LCD display  34  of the electronic device  10  is depicted in  FIG. 4  in accordance with one embodiment. The depicted LCD display  34  includes an LCD panel  42  and a backlight unit  44 , which may be assembled within a frame  46 . As may be appreciated, the LCD panel  42  may include an array of pixels configured to selectively modulate the amount and color of light passing from the backlight unit  44  through the LCD panel  42 . For example, the LCD panel  42  may include a liquid crystal layer, one or more thin film transistor (TFT) layers configured to control orientation of liquid crystals of the liquid crystal layer via an electric field, and polarizing films, which cooperate to enable the LCD panel  42  to control the amount of light emitted by each pixel. Additionally, the LCD panel  42  may include color filters that allow specific colors of light to be emitted from the pixels (e.g., red, green, and blue). 
     The backlight unit  44  includes one or more light sources  48 . Light from the light source  48  is routed through portions of the backlight unit  44  (e.g., a light guide and optical films) and generally emitted toward the LCD panel  42 . In various embodiments, light source  48  may include a cold-cathode fluorescent lamp (CCFL), one or more light emitting diodes (LEDs), or any other suitable source(s) of light. Further, although the LCD  34  is generally depicted as having an edge-lit backlight unit  44 , it is noted that other arrangements may be used (e.g., direct backlighting) in full accordance with the present technique. 
     Referring now to  FIG. 5 , an example of a circuit view of pixel-driving circuitry found in an LCD  34  is provided. For example, the circuitry depicted in  FIG. 5  may be embodied on the LCD panel  42  described above with respect to  FIG. 4 . The pixel-driving circuitry includes an array or matrix  54  of unit pixels  60  that are driven by data (or source) line driving circuitry  56  and scanning (or gate) line driving circuitry  58 . As depicted, the matrix  54  of unit pixels  60  forms an image display region of the LCD  34 . In such a matrix, each unit pixel  60  may be defined by the intersection of data lines  62  and scanning lines  64 , which may also be referred to as source lines  62  and gate (or video scan) lines  64 . The data line driving circuitry  56  may include one or more driver integrated circuits (also referred to as column drivers) for driving the data lines  62 . The scanning line driving circuitry  58  may also include one or more driver integrated circuits (also referred to as row drivers). 
     Each unit pixel  60  includes a pixel electrode  66  and thin film transistor (TFT)  68  for switching the pixel electrode  66 . In the depicted embodiment, the source  70  of each TFT  68  is electrically connected to a data line  62  extending from respective data line driving circuitry  56 , and the drain  72  is electrically connected to the pixel electrode  66 . Similarly, in the depicted embodiment, the gate  74  of each TFT  68  is electrically connected to a scanning line  64  extending from respective scanning line driving circuitry  58 . 
     In one embodiment, column drivers of the data line driving circuitry  56  send image signals to the pixels via the respective data lines  62 . Such image signals may be applied by line-sequence, i.e., the data lines  62  may be sequentially activated during operation. The scanning lines  64  may apply scanning signals from the scanning line driving circuitry  58  to the gate  74  of each TFT  68 . Such scanning signals may be applied by line-sequence with a predetermined timing or in a pulsed manner. 
     Each TFT  68  serves as a switching element which may be activated and deactivated (i.e., turned on and off) for a predetermined period based on the respective presence or absence of a scanning signal at its gate  74 . When activated, a TFT  68  may store the image signals received via a respective data line  62  as a charge in the pixel electrode  66  with a predetermined timing. 
     The image signals stored at the pixel electrode  66  may be used to generate an electrical field between the respective pixel electrode  66  and a common electrode. Such an electrical field may align liquid crystals within a liquid crystal layer to modulate light transmission through the LCD panel  42 . Unit pixels  60  may operate in conjunction with various color filters, such as red, green, and blue filters. In such embodiments, a “pixel” of the display may actually include multiple unit pixels, such as a red unit pixel, a green unit pixel, and a blue unit pixel, each of which may be modulated to increase or decrease the amount of light emitted to enable the display to render numerous colors via additive mixing of the colors. 
     In some embodiments, a storage capacitor may also be provided in parallel to the liquid crystal capacitor formed between the pixel electrode  66  and the common electrode to prevent leakage of the stored image signal at the pixel electrode  66 . For example, such a storage capacitor may be provided between the drain  72  of the respective TFT  68  and a separate capacitor line. 
     Certain components for processing image data and rendering images on an LCD  34  based on such data are depicted in block diagram  80  of  FIG. 6  in accordance with an embodiment. In the illustrated embodiment, a graphics processing unit (GPU) in block  82 , or some other processor  18 , transmits data in block  84  to a timing controller in block  86  of the LCD  34 . The data generally includes image data that may be processed by circuitry of the LCD  34  to drive the unit pixels  60  of, and render an image on, the LCD  34 . The timing controller, in block  86 , may then send signals to, and control operation of, one or more column drivers (or other data line driving circuitry  56 ) in block  88  and one or more row drivers in block  90  (or other scanning line driving circuitry  58 ). These column drivers and row drivers may generate analog signals for driving the various unit pixels  60  of a pixel array of the LCD  34  in block  92  to generate images on the LCD  34 . 
     However, as previously noted, these images on the LCD  34  may not be of a uniform brightness across various devices  10 .  FIG. 7  illustrates a first graph  94  and a second graph  96  illustrating variations in electronic devices  10  made, for example, by various manufacturers or in various batches. Graph  94  illustrates that for a given current applied to the LCD  34 , the brightness as measured in nits, may be distributed (e.g., as a Gaussian distribution or another distribution) for a given set of units. That is, the brightness for a set of units (i.e., devices  10 ) may vary across the distribution of graph  94  such that the majority of units may fall within a particular range  98 , however, the units that fall outside this range  98  may be perceived as having quality issues regarding brightness of their LCDs  34 . 
     Graph  96  of  FIG. 7  illustrates the results of adjusting each electronic device  10  from various manufacturers or in various batches to display an image at a common brightness. That is, instead of driving the LCDs  34  of the devices  10  at a common current, the devices  10  may be driven to a common brightness, thus alleviating the appearance of quality issues regarding brightness of the devices  10 . However, as illustrated in graph  96 , driving the devices  10  to a common brightness may generate a distribution in the amount of power consumed by the devices (e.g., a Gaussian distribution or another distribution). That is, the consumption of power for a set of units (i.e., devices  10 ) based on current applied to the LCD  34  may vary across the distribution of graph  96  such that the majority of units may fall within a particular range  100 , however, the units that fall outside this range  100  may be perceived as having quality issues regarding power consumption (i.e., battery life) for the devices  10 . 
     To reduce the number of devices that fall outside ranges  98  and  100 , calibration of the individual devices  10  may be performed. This calibration of the devices  10  may generate graphs  102  and  104 , as illustrated in  FIG. 8 . Graph  102  is similar to graph  94  in that graph  102  illustrates that for a given current applied to the LCD  34 , the brightness as measured in nits, may be distributed for a given set of units. That is, the brightness for a set of units may vary across the distribution of graph  102  such that the majority of units may fall within a particular range  106 . However, it should be noted that this range  106  is smaller than range  92  and that the total width of the distribution of graph  102  is smaller than the distribution illustrated in graph  94 . Thus, fewer units (i.e., devices  10 ) may be perceived as having quality issues regarding brightness of their respective LCDs  34 . 
     Graph  104  of  FIG. 8  is similar to graph  96  in that graph  104  illustrates the results of adjusting each electronic device  10  from various manufacturers or in various batches to display an image around a common brightness value. That is, instead of driving the LCDs  34  of the devices  10  at a common current, the devices  10  may be driven to a common brightness. Furthermore, by applying calibrating the devices, the range of currents applied may fall into range  108 . Moreover, this range  108  is smaller than range  100 , and that the total width of the distribution of graph  104  is smaller than the distribution illustrated in graph  96 . Thus, fewer units (i.e., devices  10 ) may be perceived as having quality issues regarding power consumption due to powering their respective LCDs  34 . 
     Graph  110  of  FIG. 9  illustrates the results of the calibration of each device  10 , as will be discussed in greater detail below. Graph  110  represents, for example, the luminance curve  112  of a given LCD  34  for a particular device  10 . This luminance curve may be generated based upon, for example, point  114 , point  116 , and point  116 . Point  114  may correspond to the current necessary to generate a first user perceived brightness  120  of the LCD  34  when tested at a first condition (for example, a user icon  40 , such as a slider that may allow for user control of the brightness of the display  34 , is set to its lowest level), which is accomplished at a true brightness  122  (e.g., luminance) of the display  12 . Similarly, point  116  may correspond to the current necessary to generate a second user perceived brightness  124  of the LCD  34  when tested at a second condition (for example, a user icon  40 , such as a slider that may allow for user control of the brightness of the display  34 , is set to a midpoint level), which is accomplished at a true brightness  126  (e.g., luminance) of the display  12 . Finally, point  118  may correspond to the maximum brightness  128  of the LCD  34 , accomplished at a determined maximum current at a third condition (for example, a user icon  40 , such as a slider that may allow for user control of the brightness of the display  34 , is set to a highest level), which is accomplished at a true brightness  130  (e.g., luminance) of the display. In some embodiments, the brightness levels  120 ,  122 ,  124 ,  126 ,  128 , and  130  of the LCD  34  and/or the currents to drive them may be preset as finite values. In other embodiments, the brightness levels  120 ,  122 ,  124 ,  126 ,  128 , and  130  of the LCD  34  and/or the currents to drive them may experimentally determined Based on points  114 ,  116 , and  118 , the luminance curve  112 , as well as the calibration values for the LCD  34  to generate that curve  112  may be determined for a given device  10 . 
     The flow chart  132  of  FIG. 10  illustrates a technique for determining the calibration values for a device  10 . In step  134 , the LCD  34  of the device  10  may be driven at a first current, for example, 10 mA, 11 mA, 12 mA, 13 mA, 14 mA, 15 mA, 16 mA, 17 mA, 18 mA, 19 mA, 20 mA, 21 mA, 22 mA, 23 mA, 24 mA, 25 mA, or another value. The brightness of the LCD  34  may then be measured in step  136 . The brightness may be externally determined by a tester and physically input into the device  10  as part of the testing process or the brightness may be determined internally by the device  10 , for example, the through the use of the ambient light sensor  41 , which may be adjusted to measure the light transmitted to the LCD  34 . In step  138 , a first current adjustment may be determined. This first current adjustment may represent, for example, a calibration used to calibrate a backlight unit  44  of the LCD  34 . This determination step  138  may be determined as described below with respect to  FIG. 11 . 
       FIG. 11  illustrates a flow chart  140  that may outline the process for determining the first current adjustment in step  138  of  FIG. 10 . In step  142 , the brightness measurement is received, for example, from user input or the ambient light sensor  41 . In step  144 , this brightness measurement may then be compared to low and high threshold values, such as a minimum operating brightness threshold and a maximum operating brightness threshold corresponding to the brightness  128  of the LCD  34  when operating at the third condition (for example, brightness of the LCD  34  when a GUI slider icon  40  is located at a maximum value of a displayed range). In one embodiment, the low threshold value may be a brightness of, for example, 350 nits, 400 nits, 450 nits, 500 nits, 550 nits, or another value, while the high threshold value may be a brightness of, for example, 550 nits, 600 nits, 650 nits, 700 nits, 750 nits, or another value. In step  146 , if the brightness measurement falls between the low threshold and the high threshold, no adjustment to the current driving the LCD  34  is deemed necessary in step  148  (i.e., no calibration value is utilized). If, however, the brightness measurement falls below the low threshold, a current adjustment value is identified in step  150 . This current adjustment value may be determined, for example, as an adjustment to the maximum current used to provide the brightness  124  by the equation: 
     
       
         
           
             
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     That is, the current adjustment is set as the lesser of a preset maximum current for brightness  128  of the device  10  and a function of the measured brightness at the tested current against the low threshold. If, the brightness measurement is above the high threshold, a current adjustment value is identified in step  150 . This current adjustment value may be determined, for example, as an adjustment to the maximum current used to provide the brightness  128  by the equation: 
     
       
         
           
             
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     That is, the current adjustment is set as the greater of a preset minimum current for the device  10  for operational brightness  128  of the device  10  and a function of the measured brightness at the tested current against the high threshold. 
     Returning to  FIG. 10 , the first current adjustment (determined as described in  FIG. 11 ) is stored for use by the device  10  in step  152 . A second determination may then begin for determining a second calibration value for the device  10 . In step  154 , the LCD  34  of the device  10  may be driven at a second current, for example, 2 mA, 2.5 mA, 3 mA, 3.5 mA, 4 mA, 4.5 mA 5 mA, 5.5 mA, 6 mA, 6.5 mA, 7 mA, or another value. The brightness of the LCD  34  may then be measured in step  156 . Again, the brightness may be externally determined by a tester and physically input into the device  10  as part of the testing process or the brightness may be determined internally by the device  10 , for example, the through the use of the ambient light sensor  41 , which may be adjusted to measure the light transmitted to the LCD  34 . In step  158 , a second current adjustment may be determined. This second current adjustment may represent, for example, a second calibration used to calibrate a backlight unit  44  of the LCD  34 . This determination step  158  may be also determined as described below with respect to  FIG. 11 . 
       FIG. 11  illustrates a flow chart  140  that may outline the process for determining the second current adjustment in step  158  of  FIG. 10 . In step  142 , the brightness measurement is received, for example, from user input or the ambient light sensor  41 . In step  144 , this brightness measurement may then be compared to low and high threshold values, such as a minimum brightness threshold and a maximum brightness threshold corresponding to the brightness  124  of the LCD  34  when operating at a second condition (for example, brightness of the LCD  34  when a GUI slider icon  40  is located at a midpoint value of a displayed range). In one embodiment, the low threshold value may be a brightness of, for example, 100 nits, 120 nits, 140 nits, 160 nits, or another value, while the high threshold value may be a brightness of, for example, 140 nits, 160 nits, 180 nits, 200 nits, or another value. In step  146 , if the brightness measurement falls between the low threshold and the high threshold, no adjustment to the current driving the LCD  34  is deemed necessary in step  148  (i.e., no calibration value is utilized). If, however, the brightness measurement falls below the low threshold, a current adjustment value is identified in step  150 . This current adjustment value may be determined, for example, as an adjustment to the middle current used to provide the brightness  124  by the equation: 
     
       
         
           
             
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     That is, the current adjustment is set as the lesser of a preset maximum current for brightness  124  of the device  10  (which may be lower than the preset maximum current for brightness  128  discussed above) and a function of the measured brightness at the tested current against the low threshold. If, the brightness measurement is above the high threshold, a current adjustment value is identified in step  150 . This current adjustment value may be determined, for example, as an adjustment to the middle current used to provide the brightness  124  by the equation: 
     
       
         
           
             
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     That is, the current adjustment is set as the greater of a preset minimum current for the device  10  for brightness  124  of the device  10  and a function of the measured brightness at the tested current against the high threshold. Returning to  FIG. 10 , the second current adjustment (determined as described in  FIG. 11 ) is stored for use by the device  10  in step  152 . Thus, each device  10  may have adjustment factors stored therein such that during operation of the device  10  (i.e., during rest periods or active periods) the current transmitted to the LCD  34  of the device  10  may be adjusted based on specific physical characteristic of that device  10  (i.e., if the LCD  34  would appear dimmer to a user when in use relative to other devices  10 , more current may be utilized to drive the LCD  34 , while if the LCD  34  would appear brighter to a user when in use relative to other devices  10 , less current may be utilized to drive the LCD  34 ). 
     It should be noted that the processes discussed in  FIGS. 10 and 11  may be performed by hardware, software (i.e., code or instructions stored on a tangible machine readable medium such as memory  20  or storage  22  and executed by, for example, processor  18 ), or some combination thereof. Additionally or alternatively, a processor and memory and/or storage may be utilized in the backlight calibration unit  30  to perform the steps recited in  FIGS. 10 and 11 . 
     The determination of calibration values stored in steps  152  and  160  discussed above may be performed by a manufacturer and/or by a user. Additionally, the determination of these brightness calibration values may allow for dynamically generated calibration values based on an individual device  10 , thus reducing the overall memory footprint of the device (since only particular adjustment values are stored for a device  10 ). Moreover, as these values may be determined on a device by device basis, the technique may be scalable and applicable across product lines (i.e. with mp3 players, phones, and tablet devices), since the techniques are not panel or product dependent. The techniques may also allow for less power consumption variation and brightness variation across devices  10 , and, thus, may allow for greater customer satisfaction and less quality complaints deriving from non-standard operation of similar devices  10 . 
     The stored calibration values may be utilized by the device  10  during operation.  FIG. 12  illustrates a block diagram of the backlight calibration unit  30  interacting with the backlight unit  44 . Backlight calibration unit  30 , as illustrated, may utilize information from the interface brightness block  162 , the device luminance curve block  164 , the product luminance curve block  166 , and the command generation block  168  to generate information that may be utilized by the backlight controller integrated circuit (IC)  170  to drive the backlight unit  44 . In one embodiment, the processes discussed below with respect to  FIGS. 12 and 13  may be performed by hardware, software (i.e., code or instructions stored on a tangible machine readable medium such as memory  20  or storage  22  and executed by, for example, processor  18 ), or some combination thereof. Additionally or alternatively, the processor executing the instructions may be the backlight controller IC  170  operating in conjunction with memory and/or storage located in the backlight calibration unit  30 . Finally, it is envisioned that each of the interface brightness block  162 , the device luminance curve block  164 , the product luminance curve block  166 , and the command generation block  168  may comprise values stored in memory that may be located in memory  20  or storage  22 , located in memory internal to the backlight calibration unit  30 , may be internal to the backlight controller integrated circuit (IC)  170 , or some combination thereof. 
     The interface brightness block  162 , may include a curve or set of values indicative of predetermined response characteristics of the device  10  in response to an input. For example, the interface brightness block  162  may include a values or a curve representing preset values that corresponds to the desired response of the device in relation to a user interfacing with a GUI  38  of the device, for example, sliding a brightness icon  40  along the LCD  34  to allow for user specified brightness levels to be emitted from the device  10 . Thus, the interface brightness block  162  may receive inputs from the user slider  172  (e.g., signals transmitted to the interface brightness block  162  that relate the input of a user relating to a brightness slider or other GUI to the interface brightness block  162 ) and may provide a location along the a curve or provide a value from a set of values indicative of the luminance of the device associated with the inputs received. This information may then be utilized by the device luminance curve block  164 . 
     Thus, information from this interface brightness block  162  may be utilized in conjunction with information stored in the device luminance curve block  164 . The information in the device luminance curve block  164  may correspond to the luminance curve  112  of a given LCD  34  for a particular device  10 , as previously discussed with respect to  FIG. 9 . That is, the information in the device luminance curve block  164  may correspond to the calibration values stored in steps  152  and  160  of  FIG. 11 . In one embodiment, these values may be transmitted along path  174  to other portions of the device  10  as needed. 
     Moreover, based on the interface of a user, device specific luminance characteristics may be determined based on the information stored in the device luminance curve block  164 . That is, information related to both true luminance being provided by the backlight unit  44  and information related to the perceived luminance being received by a user (e.g., user experience luminance) for a given slider location as part of a GUI  38  may be determined based on selecting a location along the curve  112  or by selecting a value from a set of values indicative of the luminance experienced by a user corresponding to a position of the slider (e.g., corresponding to the information received from the interface brightness block  162 ). This user experienced luminance value and/or the actual luminance based on, for example, the slider icon  40  position, may be provided to the product luminance curve block  166 . Additionally, this user experienced luminance value and/or the actual luminance based on, for example, the slider icon  40  position, may also be provided to other portions of the device  10 . 
     The product luminance curve block  166  may be a characteristic curve or set of values relating to the observed operation of a predetermined number of devices  10  of the same product as the device  10  in which the backlight calibration unit  30  resides. In one embodiment, the product luminance curve block  166  is populated with information relating to the average behavior of a product. This information may be determined by, for example, measuring device response characteristics for a set of devices  10  (i.e., 10, 20, 30, 40, 50, or more devices). For example, brightness of the set of devices  10  with respect to a plurality of LCD  34  currents may be measured, averaged, and linearized into the information contained in the product luminance curve block  166 . This information may include, for example, 100, 200, 300, 400, 500, 600, or more data points and a curve based on these data points may be extrapolated. In another embodiment, a polynomial related to the data points may be stored in the product luminance curve block  156 . In some embodiments, adjustment of the populated with information relating to the average behavior of a product may be aided by information the product luminance curve block  166  is populated with information relating to the average behavior of a product. 
     This product luminance curve block  166  may receive an indication of luminance that was determined in the device luminance curve block  164 . Based on this value (e.g., which may include adjustments for inherent characteristics of the device  10  as previously described in conjunction with  FIGS. 10 and 11 ), the product luminance curve block  166  may determine the relevant current to drive the device by determining a location along the a curve that corresponds to the indication of luminance indicated by the device luminance curve block  164  or the luminance curve block  166  may determine the relevant current to drive the device by selecting a value from a set of values indicative of the indication of luminance from the device luminance curve block  164 . That is, the product luminance curve block  166  operates to receive a specific luminance value of the backlight and look-up and output the corresponding current related to that luminance. 
     The command generation block  168  may receive an indication of the current determined in the product luminance curve block  166 . The command generation block  168  may include a curve or a set of values operate as an inverse function of the operation of the backlight controller IC  170 . That is, the backlight controller IC  170  may be a chip that includes a signal converter (e.g., an analog to digital converter or a digital to analog converter), or the backlight controller IC  170  may be the signal converter itself (e.g., an analog to digital converter or a digital to analog converter). When, the backlight controller IC  170  converts a signal, the output from the backlight controller IC  170  may not always correspond to the desired output. That is, noise or other factors may cause the converted signal to deviate from its intended value. 
     To remedy this potential error, the command generation block  168  may include a curve or a set of values that takes into account faults generated by the backlight controller IC  170  during signal conversion. That is, the command generation block  168  may receive an indication of the current determined in the product luminance curve block  166  and may be able to provide a determination of a location along the a curve that corresponds to a desired input to cause the desired current (from the product luminance curve block  166 ) to issue from the backlight controller IC  170 . This determination may instead include selection a value from a set of values indicative of a desired input to cause the desired current (from the product luminance curve block  166 ) to issue from the backlight controller IC  170 . The determination may be, for example, a current value that may be fed to the backlight controller IC  170  to generate an accurate current from the backlight controller IC  170  that corresponds to the current determined in the product luminance curve block  166 . 
       FIG. 13  illustrates a second block diagram of the backlight calibration unit  30  interacting with the backlight unit  44 . Again, the backlight calibration unit  30 , as illustrated, may utilize information from the interface brightness block  162 , the device luminance curve block  164 , the product luminance curve block  166 , and the command generation block  168  to generate information that may be utilized by the backlight controller integrated circuit (IC)  170  to drive the backlight unit  44 . As illustrated in  FIG. 13 , a desired brightness level may not be received from the user slider  172 , but rather along path  176  (e.g., from software stored in memory  20  or storage  22  and executed by processor  18 ). This brightness level may correspond to a desired luminance for the backlight unit  44  and may, in some embodiments, take into account information transmitted from path  174 . 
     The signal from path  176  may include an indication that the backlight is to be dimmed to a certain luminance, for example, in response to a battery threshold level being passed (e.g., a determination to reduce the brightness of the device by a certain percent when the battery life of the device falls below a preset or selected threshold). This indication of a desired luminance may be received along path  178 . 
     The device luminance curve block  164  may determine based on the desired luminance value received a location along the curve  112  corresponding to the desired luminance value (e.g., received from path  178 ) or may select a value from a set of values indicative of the desired luminance value. This determined luminance value may be provided to the interface brightness block  162 . 
     The interface brightness block  162  may receive an indication of the luminance value determined by the device luminance curve block  164  and may determine a corresponding value or a location on a curve representing preset values that corresponds to the location of an icon  40  of the GUI  38  of the device, for example, sliding a brightness icon  40  along the LCD  34 , That is, based on the indication of the luminance value determined by the device luminance curve block  164 , a determination may be made as to the location a slider icon  40  should be as part of a GUI. This information may be transmitted to the user slider  172  to allow for updating of the location of the slider icon  40  with respect to the luminance value received along path  178 . 
     Additionally, the signal from path  176  may be transmitted to the product luminance curve block  166  along path  180 . As previously noted, the product luminance curve block  166  may be populated with information relating to the average behavior of a product. This information may be determined by, for example, measuring device response characteristics for a set of devices  10  (i.e., 10, 20, 30, 40, 50, or more devices). For example, brightness of the set of devices  10  with respect to a plurality of LCD  34  currents may be measured, averaged, and linearized into the information contained in the product luminance curve block  166 . This information may include, for example, 100, 200, 300, 400, 500, 600, or more data points and a curve based on these data points may be extrapolated. In another embodiment, a polynomial related to the data points may be stored in the product luminance curve block  156 . In some embodiments, adjustment of the populated with information relating to the average behavior of a product may be aided by information the product luminance curve block  166  is populated with information relating to the average behavior of a product. This information may also be adjusted, for example, utilizing information received along path  162  relating to, for example, adaptive brightness control or predicted degradation of the unit pixels  60  over time (which may tend to alter the validity of the previous information in the product luminance curve block  166 ) and/or may be adjusted to include adjustments relating to the device  10  in which the product luminance curve block  166  resides (i.e., information from the device luminance curve block  164 ). That is, information, such as unit pixel  60  degradation and/or ambient light measurements may be made at a certain rate (i.e., hourly, daily, weekly, monthly, etc.), for example, by the ambient light sensor  41 , and these measurements may be utilized to update the information in the product luminance curve block  166  so that the information in the product luminance curve block  166  more accurately represent the average behavior of a product. 
     This product luminance curve block  166  may receive an indication of luminance that was transmitted along path  180 . Based on this value (e.g., which may include adjustments for inherent characteristics of the device  10  as previously described in conjunction with  FIGS. 10 and 11 ), the product luminance curve block  166  may determine the relevant current to drive the device by determining a location along the a curve that corresponds to the indication of luminance indicated by the signal from path  180  or the luminance curve block  166  may determine the relevant current to drive the device by selecting a value from a set of values indicative of the indication of luminance indicated by the signal from path  180 . That is, the product luminance curve block  166  operates to receive a specific luminance value of the backlight and look-up and output the corresponding current related to that luminance. 
     The command generation block  168  may receive an indication of the current determined in the product luminance curve block  166 . The command generation block  168  may include a curve or a set of values operate as an inverse function of the operation of the backlight controller IC  170 . That is, the backlight controller IC  170  may be a chip that includes a signal converter (e.g., an analog to digital converter or a digital to analog converter), or the backlight controller IC  170  may be signal converter itself (e.g., an analog to digital converter or a digital to analog converter). When, the backlight controller IC  170  converts a signal, the output from the backlight controller IC  170  may not always correspond to the desired output. That is, noise or other factors may cause the converted signal to deviate from its intended value. 
     To remedy this potential error, the command generation block  168  may include a curve or a set of values that takes into account faults generated by the backlight controller IC  170  during signal conversion. That is, the command generation block  168  may receive an indication of the current determined in the product luminance curve block  166  and may be able to provide a determination of a location along the a curve that corresponds to a desired input to cause the desired current (from the product luminance curve block  166 ) to issue from the backlight controller IC  170 . This determination may instead include selection a value from a set of values indicative of a desired input to cause the desired current (from the product luminance curve block  166 ) to issue from the backlight controller IC  170 . The determination may be, for example, a current value that may be fed to the backlight controller IC  170  to generate an accurate current from the backlight controller IC  170  that corresponds to the current determined in the product luminance curve block  166 . 
     In this manner, the command generation block  168  may adjust the values (e.g., current values) transmitted to the backlight controller IC  170  and, thus, allow for more accurate backlight control. It should be noted that the commands issued from the command generation block  168  may include commands related to a duty factor, a spread spectrum, or any backlight power control of the backlight unit  44 . 
     The backlight calibration unit  30  described above allows for handshaking between the blocks  162 ,  164 ,  166 , and  168  with limited computation and use of memory since, for example, each of the blocks  162 ,  164 , and  166  may transmit information in a common unit, e.g., in terms of luminance Thus, as a device  10  operates, for example, moving from one brightness level to another, the device  10  may utilize dynamically calculated parameters to account for device specific nuances regarding driving the backlight unit  44 . 
     The specific embodiments described above have been shown by way of example, and it should be understood that these embodiments may be susceptible to various modifications and alternative forms. It should be further understood that the claims are not intended to be limited to the particular forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

Metadata:
Filing Date: 20120914
Publication Date: 20141209
Grant Date: 20141209
Priority Date: 20120608
Inventors: SYED TAIF AHMED
VILLAMIZAR DANIEL A.
DOYLE DAVID ANDREW
BARNHOEFER ULRICH T.
DUGGINENI VENU MADHAV
Assignee: APPLE INC
CPC Classifications: [{"code": "G09G5/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2360/145", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/0693", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/006", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01J1/0233", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J1/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2320/0633", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/006", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01J1/0271", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2320/0606", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/0606", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01J1/18", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J1/0233", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2360/145", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/3406", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G3/3406", "inventive": true, "first": false, "tree": "[]"}, {"code": "G01J1/4204", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01J1/4204", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01J1/0219", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G2360/144", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01J1/0271", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G5/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01J1/0219", "inventive": true, "first": false, "tree": "[]"}, {"code": "G09G3/3611", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/0633", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2360/144", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G2320/0693", "inventive": false, "first": false, "tree": "[]"}, {"code": "G09G3/3611", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 49714900