Error detection in LED packages

Abstract

Disclosed is error detection in light-emitting diode (LED) packages, and more particularly in LED packages. The LED packages are arranged for cascaded communication as part of a larger LED display. Independent active electrical elements are incorporated with each LED package to facilitate active matrix addressing from the data stream, validate the input error detection code, and generate a new output error detection code in the data stream. Each electrical element within each LED package can independently modify one or more portions of received data in the data stream, transmit the modified data to the next downstream LED package, and generate an output error detection code based on the modified data. When the active electrical element identifies corrupted data based on the input error detection code, it can intentionally corrupt the generated output error detection code so that the downstream LED package further identifies that its data is corrupted.

Description

[Technical Field]

[0001] This disclosure relates to lighting devices that include light emitting diode (LED) packages, and more particularly to error detection in LED packages. [Background technology]

[0002]

[0002] Light-emitting diodes (LEDs) are solid-state devices that convert electrical energy into light and typically contain one or more active layers (or regions) of semiconductor material disposed between oppositely doped n-type and p-type layers. When a bias is applied across the doped layers, holes and electrons are injected into the active layer(s), where they recombine to produce light, e.g., visible or ultraviolet emission.

[0003]

[0003] LEDs have been widely adopted in a variety of illumination situations, including for backlighting liquid crystal display (LCD) systems (e.g., as a replacement for cold cathode fluorescent lamps) and for direct-view LED displays. Applications using LED arrays include vehicle headlamps, roadway illumination, lighting fixtures, and a variety of indoor, outdoor, and specialty applications. Desirable characteristics of LED devices include high luminous efficacy and long lifetime.

[0004]

[0004] Conventional LCD systems require polarizers and color filters (e.g., red, green, and blue) that inherently reduce light efficiency. Direct-view LED displays, which use self-emitting LEDs that eliminate the need for backlights, polarizers, and color filters, offer high light efficiency.

[0005]

[0005] Large, multicolor, direct-view LED displays (including full-color LED video screens) typically contain many individual LED panels, packages, and / or components, providing an image resolution determined by the distance between adjacent pixels, or "pixel pitch." Direct-view LED displays typically include tricolor displays with arrays of red, green, and blue (RGB) LEDs and bicolor displays with arrays of red and green (RG) LEDs. Other colors and color combinations may also be used. For many LED display systems, it is desirable to form LED color groups for each pixel, e.g., the primary colors red, green, and blue (RGB), which define the vertices of a triangle (or polygon) on a chromaticity diagram. This polygon defines the so-called color gamut of the display device, the area of ​​which represents all of the possible colors the display device can produce. A wider color gamut indicates the ability to produce more colors than a display device with a narrower color gamut. Large displays intended for viewing from long distances (e.g., electronic billboards and stadium displays) typically have a relatively large pixel pitch and usually include independent LED arrays with multicolor (e.g., red, green, and blue) LEDs that can be independently operated to form what appears to the viewer as a full-color pixel. Medium-sized displays with relatively short viewing distances require a smaller pixel pitch (e.g., 3 mm or less) and may include panels with an array of red, green, and blue LED components mounted on a single electronic device mounted on a driver printed circuit board that controls the LEDs. The driver printed circuit board is typically densely packed with electrical devices, including capacitors, field-effect transistors (FETs), decoders, microcontrollers, and the like, for driving the display's pixels. As pixel pitch continues to decrease for higher-resolution displays, the density of such electrical devices becomes higher, corresponding to an increase in the number of pixels for a given panel area. This tends to make LED panels for display applications more complex and more expensive. Summary of the Invention [Problem to be solved by the invention]

[0006] The art continues to strive for improved LED array devices having small pixel pitches while overcoming the limitations associated with conventional devices and manufacturing methods. [Means for solving the problem]

[0007]

[0007] This disclosure relates to lighting devices including light-emitting diode (LED) packages, and more particularly to error detection in LED packages. The disclosure discloses LED packages configured for cascade communication and active matrix addressing as part of a larger LED display, such that each LED package can form an LED pixel or grouping of LED pixels in the LED display. A separate active electrical element is incorporated with each LED package to validate an input error detection code and generate a new output error detection code in the data stream to facilitate active matrix addressing from the data stream. The active electrical element in each LED package can independently modify one or more portions of received data in the data stream, transmit the modified data to the next downstream LED package, and generate an output error detection code based on the modified data. When the active electrical element identifies corrupted data based on the input error detection code, it may intentionally corrupt the generated output error detection code so that the downstream LED packages further identify their respective data as corrupted.

[0008] In one aspect, an LED package includes at least one LED chip and an active electrical element electrically coupled to the at least one LED chip, the active electrical element configured to receive a data block and an input error detection code from a communication channel, modify at least a portion of the data block, and generate an output error detection code that replaces the input error detection code, the output error detection code corresponding to the modified at least a portion of the data block. In certain embodiments, the active electrical element includes logic for providing the output error detection code as a corrupted output error detection code. In certain embodiments, the active electrical element is configured to identify data corruption in the data block and provide the output error detection code as the corrupted output error detection code, such that the data corruption is identified by another element configured to receive the corrupted output error detection code. In certain embodiments, the active electrical element is configured to generate a calculated error detection code based on the data block and at least a portion of the modified data block, and to invert the value of a last bit of the calculated error detection code to generate a corrupted output error detection code.

[0009] In a particular embodiment, the input error detection code is an input cyclic redundancy check (CRC) and the output error detection code is an output CRC. In a particular embodiment, the active electrical element comprises a CRC decoder configured to receive the input CRC and a CRC encoder configured to generate the output CRC. In a particular embodiment, the active electrical element comprises a first bidirectional communication port and a second bidirectional communication port. In a particular embodiment, the active electrical element is configured to detect an input signal at the first bidirectional communication port and assign the first bidirectional communication port as an input port and assign the second bidirectional communication port as an output port.

[0010]

[0010] The LED package may further include a submount carrying at least one LED chip and an active electrical element, an encapsulating layer on the submount and on a portion of the at least one LED chip and the active electrical element, and package bond pads electrically coupled to the at least one LED chip and the active electrical element.

[0011] In another aspect, an LED package includes at least one LED chip and an active electrical element electrically connected to the at least one LED chip, the active electrical element configured to receive an input error detection code from a communication channel, generate a corrupted output error detection code, and transmit the corrupted output error detection code along the communication channel or to another communication channel. In a particular embodiment, the input error detection code is an input cyclic redundancy check (CRC), and the corrupted output error detection code is a corrupted output CRC. In a particular embodiment, the active electrical element further includes a CRC encoder, a CRC decoder, and a CRC corruptor that receives a data block from the communication channel and identifies data corruption in the data block to generate a corrupted output CRC. In a particular embodiment, the active electrical element is further configured to modify at least a portion of the data block as the data block passes through the active electrical element and return the modified data block to the communication channel or to another communication channel to generate the corrupted output CRC. In certain embodiments, the active electrical element is configured to generate a calculated CRC based on the input CRC and at least a portion of the modified data block, and to invert the value of the last bit of the calculated CRC to generate a corrupted output CRC. In certain embodiments, the active electrical element comprises a first bidirectional communication port and a second bidirectional communication port. The LED package may further comprise a submount carrying the at least one LED chip and the active electrical element, an encapsulation layer on the submount and over a portion of the at least one LED chip and the active electrical element, and package bond pads electrically coupled to the at least one LED chip and the active electrical element.

[0012] In another aspect, an LED package includes at least one LED chip and an active electrical element electrically connected to the at least one LED chip, the active electrical element configured to receive an input error detection code from a communication channel, generate a calculated error detection code based on the input error detection code, and invert a last bit of the calculated error detection code to generate an output error detection code. In a specific embodiment, the input error detection code is an input cyclic redundancy check (CRC), the calculated error detection code is a calculated CRC, and the output error detection code is an output CRC. In a specific embodiment, the active electrical element is configured to transmit the output CRC to the communication channel or to another communication channel. In a specific embodiment, the active electrical element is configured to receive a data block from the communication channel and identify data corruption in the data block to generate the output CRC. In a specific embodiment, the active electrical element is further configured to modify at least a portion of the data block that the active electrical element transmits to the communication channel or to another communication channel. In certain embodiments, the active electrical element comprises a first bidirectional communication port and a second bidirectional communication port. The LED package may further comprise a submount carrying the at least one LED chip and the active electrical element, an encapsulation layer on the submount and over a portion of the at least one LED chip and the active electrical element, and package bond pads electrically coupled to the at least one LED chip and the active electrical element.

[0013] In another aspect, any of the foregoing aspects may be used individually or together, and / or various independent aspects and features described herein may be combined to further advantage. Any of the various features and elements disclosed herein may be combined with one or more of the other disclosed features and elements, unless otherwise indicated herein.

[0014] Those skilled in the art will appreciate the scope of the present disclosure and realize further aspects of the present disclosure after reading the following detailed description of the preferred embodiments in conjunction with the accompanying drawings.

[0015] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate several aspects of the present disclosure and, together with the description, serve to explain the principles of the disclosure. [Brief explanation of the drawings]

[0015] [Figure 1]

[0016] FIG. 1A is a top view of the front of a representative display panel for a light-emitting diode (LED) display that includes a plurality of active LED pixels.

[0017] FIG. 1B is a bottom view of the rear of the exemplary display panel of FIG. 1A. [Figure 2A]

[0018] 1B is a bottom view of an LED package that may represent one of the LED pixels of FIG. 1A at a manufacturing step of mounting the LED and active electrical elements to a submount. [Figure 2B]

[0019] FIG. 2B is a cross-sectional view taken along the line AA in FIG. 2A. [Figure 2C]

[0020] 2C is a cross-sectional view of the LED package of FIG. 2B in a subsequent manufacturing step of forming an encapsulating layer and various electrical connections. [Figure 2D]

[0021] FIG. 2D is a simplified top view of the LED package of FIG. 2C. [Figure 2E]

[0022] FIG. 2F is a simplified bottom view of the LED package of FIG. 2E. [Figure 3]

[0023] FIG. 1 is a schematic block diagram illustrating details of an LED package and integrated active electrical elements configured to process error detection codes according to the principles of the present disclosure. [Figure 4]

[0024] FIG. 1 is a block diagram illustrating cascade communication for LED packages according to the principles of the present disclosure. [Figure 5]

[0025] FIG. 5 is a diagram similar to that of FIG. 4, further illustrating the progression of data bits through multiple LED packages after five clock cycles of cascaded communication. DETAILED DESCRIPTION OF THE INVENTION

[0016]

[0026] The following embodiments represent the necessary information to enable one skilled in the art to practice the embodiments and illustrate the best modes for practicing the embodiments. Upon reading the following description in light of the accompanying drawings, one skilled in the art will understand the concepts of the present disclosure and will recognize applications of these concepts not specifically described herein. It is understood that these concepts and applications fall within the scope of this disclosure and the appended claims.

[0017]

[0027] Although terms such as "first," "second," etc. may be used herein to describe various elements, it should be understood that these elements should not be limited by these terms. These terms are used merely to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element, without departing from the scope of the present disclosure. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0018]

[0028] When an element, e.g., a layer, region, or substrate, is described as being "on" or extending "over" another element, it is understood that the element may be directly on or extending directly onto the other element, or intervening elements may be present. In contrast, when an element is described as being "directly on" or extending "directly onto" another element, there are no intervening elements. Similarly, when an element, e.g., a layer, region, or substrate, is described as being "on" or extending "over" another element, it is understood that the element may be directly on or extending directly onto the other element, or intervening elements may be present. In contrast, when an element is described as being "directly on" or extending "directly onto" another element, there are no intervening elements. It is further understood that when an element is described as being "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

[0019]

[0029] Relative terms, such as "lower" or "upper" or "upper" or "bottom" or "horizontal" or "vertical," may be used herein to describe the relationship of one illustrated element, layer, or region to another element, layer, or region. It will be understood that these terms and the descriptions above are intended to encompass different orientations of the device in addition to the orientation shown in the figures.

[0020]

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. It will be further understood that the terms "comprise," "include," "have," and / or "having," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0021]

[0031] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be construed to have a meaning consistent with the meaning of those terms in the context of the present specification and the relevant art, and will not be construed in an idealized or overly formal sense unless expressly defined as such herein.

[0022]

[0032] Embodiments are described herein with reference to schematic illustrations of embodiments of the present disclosure. Accordingly, actual dimensions of layers and elements may vary, and variations from the shapes of the illustrations are expected as a result of, for example, manufacturing techniques and / or tolerances. For example, areas shown or described as square or rectangular may have rounded or curved features, and areas shown as straight may have some irregularities. Accordingly, the regions shown in the figures are schematic, and the shapes of the regions are not intended to illustrate the exact shape of a device or to limit the scope of the present disclosure. Furthermore, the size of some structures or regions may be exaggerated relative to other structures or regions for illustrative purposes and, as a result, are provided to illustrate the general structure of the present subject matter and may or may not be drawn to scale. Elements common between figures may be identified herein with common element numbers and may not be described again later.

[0023]

[0033] The present disclosure relates to lighting devices including light-emitting diode (LED) packages, and more particularly to error detection in LED packages. The disclosure discloses LED packages arranged for cascade communication and active matrix addressing as part of a larger LED display, such that each LED package can form an LED pixel or grouping of LED pixels in the LED display. A separate active electrical element is incorporated with each LED package to facilitate active matrix addressing from the communication channel, to validate an input error detection code, and to generate a new output error detection code. The active electrical element in each LED package can independently modify one or more portions of received data, transmit the modified data to the next downstream LED package or other receiving element, and generate an output error detection code based on the modified data. When the active electrical element identifies corrupted data based on the input error detection code, it may intentionally corrupt the generated output error detection code so that downstream LED packages can further identify that their respective data is corrupted.

[0024]

[0034] As used herein, the terms “data stream” and “communication channel” may be used interchangeably. However, a “data stream” generally refers to at least one communication channel and a non-physical representation of data over time flowing through a collection of internal wiring and storage registers within various elements, such as controllers and active electrical devices. A “communication channel” generally refers to the physical medium that transmits the data stream. For example, a communication channel may include wiring or optical fiber with associated electrical elements, or even air in the case of radio, light, or sound waves. A given physical channel may be further divided in time or frequency to realize multiple “communication channels” within a single medium at a time, such as by varying different frequency bands. In certain embodiments, a communication channel may embody a serial digital communication channel. Certain embodiments relate to a binary communication channel, which is a single wire that can typically hold only one value at a time, which is a high or low voltage (e.g., a digital “0” or “1”), controlled by an output register of the device.

[0025]

[0035] The present disclosure relates to light emitting devices, including LEDs, LED packages, and associated LED displays, and more particularly to active control of LEDs within an LED display. An LED display may include rows and columns of LEDs forming an array of LED pixels. A particular LED pixel may include a cluster of LED chips of the same color or multiple colors; an exemplary LED pixel includes a red LED chip, a green LED chip, and a blue LED chip. In certain embodiments, an LED package may include multiple LED chips forming at least one LED pixel, and multiple such LED packages may be configured to form an array of LED pixels for an LED display. Each LED package may include its own active electrical elements configured to receive control signals and actively maintain an operating state, e.g., brightness or gray level, or color selection signal for the LED chip of the LED device while addressing other LED devices. In certain embodiments, the active electrical elements may include active circuitry, including one or more of a driver device, a signal conditioning or conversion device, a memory device, a decoder device, an electrostatic discharge (ESD) protection device, a thermal management device, and a detection device, etc. In this regard, each LED pixel in an LED display may be configured for operation by active matrix addressing. The active electrical elements may be configured to receive one or more of analog control signals, encoded analog control signals, digital control signals, and encoded digital control signals. In such configurations, strings of LED packages, each containing its own active electrical element, may be arranged for serial communication, where each active element receives data from a data stream and transmits the data to the next active electrical element in the string of LED packages.

[0026]

[0036] Embodiments of the present disclosure provide an arrangement of LED chips and active electrical elements, thereby providing LED chips in close proximity to corresponding active electrical elements within a larger LED array. In this manner, individual LED pixels of a larger display can be configured for operation with appropriate communication signals, including but not limited to active matrix addressing. Further details related to active control of LEDs and corresponding LED pixels are disclosed in U.S. Patent Application No. 16 / 815,101, entitled "Active Control of Light Emitting Diodes and Light Emitting Diode Displays," published as U.S. Patent Application Publication No. 2020 / 0312231 A1, the entire contents of which are incorporated herein by reference.

[0027]

[0037] As used herein, a layer or region of a light-emitting device or package can be considered “transparent” if at least 80% of the emitted radiation impinging on the layer or region is emitted through the layer or region. Furthermore, as used herein, a layer or region of an LED can be considered “reflective” or embody a “mirror” or “reflector” if it reflects at least 80% of the emitted radiation impinging on the layer or region. In some embodiments, the emitted radiation comprises visible light, e.g., blue and / or green LEDs with or without lumiphoric materials. In certain embodiments, a “light-transmitting” material can be configured to transmit at least 50% of the emitted radiation of a desired wavelength. In certain embodiments, an originally “light-transmitting” material can be modified to a “light-absorbing” material that transmits less than 50% of the emitted radiation of a desired wavelength by adding one or more light-absorbing materials, e.g., opaque or non-reflective materials containing gray, dark, or black particles or materials.

[0028]

[0038] The present disclosure can be useful for LED chips with various geometries, such as vertical or horizontal. Vertical LED chips typically include an anode and a cathode connection on both sides of the LED chip. Horizontal LED chips typically include both an anode and a cathode connection on the same side of the LED chip, on the opposite side of the substrate, e.g., the growth substrate. Certain embodiments disclosed herein relate to the use of flip-chip LED devices in which the light-transmitting substrate provides the exposed light-emitting surface.

[0029]

[0039] LED packages containing one or more LED chips can be arranged in many different applications to provide illumination of an object, surface, or area. In certain applications, clusters of different colored LED chips or LED packages can be arranged as pixels for LED display applications, including video displays. For example, individual clusters of red, green, and blue LED chips in an LED package can form LED pixels of a larger LED display. In certain applications, the red, green, and blue LED chips of each pixel can be packaged together as multiple LED packages, and an array of such multiple LED packages, when arranged together, forms an LED display. In this regard, each pixel may include a single LED package containing a red LED chip, a green LED chip, and a blue LED chip. In other embodiments, the red, green, and blue LED chips may be packaged separately or arranged in a chip-on-board configuration. In certain LED display applications, an array of LED pixels is arranged on a panel, sometimes called a tile or LED module, and an array of such panels is arranged together to form a larger LED display. Depending on the application, each panel of the LED display may include a different number of LED pixels. In certain applications, each panel of an LED display may include an array formed by 64 rows and 64 columns or more of LED pixels. In certain embodiments, each panel of an LED display may be configured to have a horizontal display resolution of approximately 4,000 LED pixels, or 4K resolution. For applications where a higher screen resolution is desired for the LED display, each panel may include more rows and columns of LED pixels more closely spaced from one another. Depending on the desired screen resolution, the pixel pitch may be approximately 3 millimeters (mm), or approximately 2.5 mm, or approximately 1.6 mm, or within a range of approximately 1.5 mm to approximately 3 mm, or within a range of approximately 1.6 mm to approximately 3 mm, or within a range of approximately 1.5 mm to approximately 2.5 mm.Furthermore, for fine pitch LED displays with even higher screen resolution, the pixel pitch may be configured to be less than 1 mm, or less than 0.8 mm, or within the range of about 0.5 mm to about 1 mm, or about 0.7 mm in certain embodiments.

[0030]

[0040] In conventional video display applications, LED pixels are typically configured for passive matrix addressing. As used herein, the term "passive" refers to the absence of dedicated driver elements for each LED pixel, subpixel, or LED chip. In this approach, passive LED pixels may be arranged for coupling to interface elements that provide electrical connections to independent drivers or controllers shared among several LED pixels. For example, orthogonally arranged (e.g., vertical and horizontal) conductors form rows and columns in a grid pattern, with the individual LED chips in each LED pixel defined by each intersection of the row and column. Using a common-row anode or common-row cathode matrix configuration, multiplexing sequencing may be used to enable individual control of each LED chip in the array while using fewer drivers and conductor wiring than the number of LED chips in the array, and brightness control may be provided by pulse-width modulation (PWM). In this approach, the drivers and conductors for a row or column are shared among many LED pixels, and time-division multiplexing is used to address each individual LED pixel. Due to this shared driver configuration, only each LED pixel emits light during its respective communication time. Separate drivers for controlling the display are typically located remotely from the display's pixels, for example, on a separate board or module, on a printed circuit board (PCB) mounted or otherwise mounted on the backside of each panel, or in a separate component package mounted on the backside of a common PCB that contains the array of pixels on its front side. The common PCB is typically densely packed with electrical devices, including capacitors, field-effect transistors (FETs), decoders, microcontrollers, etc., to drive each of the pixels in a particular panel. For higher-resolution displays, the density of such electrical devices increases correspondingly with the increasing number of pixels in each panel. This increases the complexity and cost of LED panels for display applications and can increase thermal density in areas with more closely spaced driver electronics.With passive matrix addressing, LED pixels are typically driven by a pulsed signal sequence. In this regard, the LED pixels may be rapidly pulsed at a particular frequency, such as 60 Hertz (Hz) or 120 Hz, depending on the display scan rate. Although the video display may not appear to be rapidly pulsing to the human eye, the video display may be detectable using image capture equipment, and in some instances, a beating effect may be observed between the video display and other pulsed displays, light sources, or image capture equipment.

[0031]

[0041] According to embodiments disclosed herein, each LED pixel of an LED display may be configured for operation using active matrix addressing. With active matrix addressing, each LED pixel is configured to actively maintain its operating state or otherwise control its drive state, e.g., brightness, gray level, or color selection, while other LED pixels are being addressed, thereby allowing each LED pixel to maintain or otherwise individually control its own drive state and provide improved viewing and / or image recording by using such equipment (e.g., a light source, other pulse-driven display, or image capture equipment) to reduce or eliminate effects caused by lower frequency pulse-driven beating. Thus, each LED pixel may be configured to maintain its respective operating state using a continuous drive signal that includes pulse-width modulation, rather than by a time-division multiplexed signal that introduces low-frequency components into the drive signal associated with passive matrix addressing. In this regard, each LED pixel may include an active electrical chip or active electrical element that may include a memory device and the ability to change the drive state of the LED pixel based on the state stored in the memory of the active electrical element. In certain embodiments, the continuous drive signal is a constant analog drive current, and the brightness level may be controlled by a pulsed method, e.g., PWM. In other embodiments, the continuous drive signal may represent a PWM signal that is not disrupted by time-multiplexed scanning of other LED pixels in the array or sub-array. In certain embodiments, the active electrical element may include active circuitry that includes one or more of driver devices, signal conditioning or conversion devices, memory devices, decoder devices, ESD protection devices, thermal management devices, detection devices, and voltage and / or current detection devices, command processing devices, and circuits, among others. In various embodiments, the active electrical element comprises an integrated circuit chip, an application-specific integrated circuit (ASIC), a microcontroller, or a field-programmable gate array (FPGA).In certain embodiments, the active electrical elements may be configured to be programmable or reprogrammable after fabrication of the active electrical elements through various memory elements and logic incorporated within the active electrical elements.

[0032]

[0042] As used herein, the terms "active electrical chip," "active electrical element," or "active electrical component" encompass any chip or component that can change the drive state of an LED based on memory or other information that can be stored within the chip or component. As used herein, the terms "active LED pixel" and "smart LED pixel" may be used interchangeably and may refer to a device that includes one or more LED devices or chips forming a pixel and the active electrical elements or chips described above. In certain embodiments, each LED pixel may comprise a single LED package configured as an active LED package that includes multiple LED chips and active electrical elements described above. This approach may reduce the number of separate electrical devices required for the LED display, such as separate electrical devices located behind the LED panel of the aforementioned LED display. Furthermore, the total operating power required to operate the LED panel may be reduced.

[0033]

[0043] In digital communications and networks, error detection codes are commonly used to detect data errors and / or corrupted data transmitted along a communications channel due to various factors, such as channel noise during transmission. Generally, a transmitting device, such as a server or master controller, may incorporate an error detection code into the data stream, and a receiving device can check for any errors in the received error detection code. During communication, the transmitting and receiving devices may continuously transmit and check the error detection code to verify the integrity of the data. A particular type of error detection code is a cyclic redundancy check (CRC). Other types of error detection codes include parity bits and checksums, among others.

[0034]

[0044] According to the principles of the present disclosure, LED packages or LED pixels can be configured for active matrix addressing and can validate an input error detection code and generate a new output error detection code for output to the same or further communication channels. Each LED package can independently modify one or more portions of the received data and transmit the modified data to the next downstream LED package or other receiving element. When an LED package modifies the data, it generates a new output error detection code corresponding to the modified data. In some examples, an LED package can detect an error using the input error detection code and then generate a new output error detection code that is intentionally corrupted to notify other LED packages of the corrupted data. Because the LED package modifies the output error detection code to reflect the modified data, intentionally corrupting the output error detection code can prevent the LED package from unintentionally correcting an error identified by the input error detection code, such that downstream LED packages cannot identify that the original data was corrupted. While the following embodiments are described in the context of a CRC, the principles discussed are applicable to any type of error detection code.

[0035]

[0045] 1A is a top view of the front surface of an exemplary display panel 10 for an LED display including a plurality of active LED pixels 12. As shown, the plurality of active LED pixels 12 can be arranged in rows and columns to form an array of active LED pixels 12 across the front surface of the display panel 10. In certain embodiments, each active LED pixel 12 includes an active electrical element capable of receiving an input signal, storing data in memory based on the input signal, changing the drive state of the LEDs in the active LED pixel 12 based on the data stored in the memory, and updating the drive state each time the memory is updated with the input signal or other internal factors. In certain embodiments, each active LED pixel 12 comprises an individual LED package including the active electrical element and a plurality of LED chips.

[0036]

[0046] FIG. 1B is a bottom view of the rear of the exemplary display panel 10 of FIG. 1A. As shown, the display panel 10 may include additional passive or active elements configured to receive, process, and distribute signals and power to the active LED pixels 12 of FIG. 1A. For example, the display panel 10 may include an input signal connector 14 and an output signal connector 16, each of which may be configured as a video source connector, including, among others, a Video Graphics Array (VGA) connector, a Digital Visual Interface (DVI) connector, a High-Definition Multimedia Interface (HDMI) connector, or a DisplayPort connector. The input and output signal connectors 14, 16 may alternatively be configured as data network connectors, such as, among others, a Universal Serial Bus (USB) or Ethernet. The display panel 10 may also include a control element 18 including control circuitry, such as, for example, a semiconductor control element. The control element 18 may be configured to receive input signals via the input signal connector 14 and to output control signals for the active LED pixels. As will be described in more detail below, the active electrical elements of each LED pixel are configured to independently change the drive state of each LED chip within the LED pixel in response to control signals received from control element 18. In certain embodiments, control element 18 comprises an integrated circuit such as one or more of an ASIC, a microcontroller, a programmable control element, and an FPGA. In certain embodiments, multiple control elements 18 may be disposed on or stacked on each display panel 10. Decoder element 20 may be configured to receive, decode, and route signals between input signal connector 14 and output signal connector 16 and control element 18. In certain embodiments, passive elements 22, such as resistors, capacitors, and inductors, may be provided to maintain appropriate power and signal levels throughout the system.The display panel 10 may further include other passive or active elements 24, which may include additional decoders, resistors, capacitors, or other electrical elements or circuits for video display. In this manner, the signal connectors 14 and 16, the control elements 18, the decoder elements 20, the passive elements 22, and the other passive or active elements 24 are overlaid on the display panel 10. In an alternative embodiment, the back surface of the display panel 10 may include another plurality of LED packages forming another array of LED pixels. In this regard, the display panel 10 may be configured for a dual-sided display application. In such an embodiment, at least some of the signal connectors 14 and 16, the control elements 18, the decoder elements 20, the passive elements 22, and the other passive or active elements 24 may be overlaid on the display panel 10 at a location other than the back surface in a configuration that provides control signals from one or more edges of the display panel 10 or from within the display panel 10 itself.

[0037]

[0047] 2A-2E illustrate various states of manufacture for an LED package 26 including multiple LEDs 28-1 through 28-3 and an active electrical element 30 according to embodiments disclosed herein. Certain aspects are discussed in the context of three LED chips 28-1 through 28-3, e.g., a red LED chip, a green LED chip, and a blue LED chip, to form an LED pixel of a display. Other aspects may relate to LED packages including at least one LED chip, up to any number of LED chips housed together with an active electrical element 30 within a common LED package. The active electrical element 30 may also be referred to as an active electrical chip or active electrical component. The LED package 26 of FIGS. 2A-2E is provided as an exemplary form of an individual one of the LED pixels 12 of FIG. 1A. It is contemplated that other LED package structures including one or more LED chips and active electrical elements described herein may be implemented as individual LED pixels of a larger LED display according to the principles of the present disclosure.

[0038]

[0048] 2A is a bottom view of the LED package 26 in a particular manufacturing state, with the LEDs 28-1 to 28-3 and the active electrical element 30 mounted on the submount 32. In particular, the LEDs 28-1 to 28-3 and the active electrical element 30 may be mounted on a first surface 32′ of the submount 32. An optically transparent die attach material may be disposed between the LEDs 28-1 to 28-3 and the submount 32 to facilitate mounting. Each of the LEDs 28-1 to 28-3 may include a corresponding cathode contact 34-1 to 34-3 (e.g., an n-type contact pad) and a corresponding anode contact 36-1 to 36-3 (e.g., a p-type contact pad). In particular embodiments, the LEDs 28-1 to 28-3 comprise individual LED chips that generate different wavelengths of light. For example, LED 28-1 may be configured to generate primarily green emitted light, LED 28-2 may be configured to generate primarily blue emitted light, and LED 28-3 may be configured to generate primarily red emitted light. Thus, the plurality of LEDs 28-1 through 28-3 may include green, blue, and red LED chips. Other combinations of LED colors and numbers are possible in other embodiments. In yet another embodiment, each of the plurality of LEDs 28-1 through 28-3 may be configured to generate primarily the same emitted light. In other embodiments, the plurality of LEDs 28-1 through 28-3 may include a micro LED structure separated into multiple active LED structure portions to form the plurality of LEDs 28-1 through 28-3, where the common active LED structure may be independently addressable.

[0039]

[0049] In certain embodiments, the active electrical element 30 is configured to receive a signal or signals and independently drive each LED of the plurality of LEDs 28-1 to 28-3. In certain embodiments, the active electrical element 30 includes a memory element, chip, or component configured to store one or more operating states for the plurality of LEDs 28-1 to 28-3 received from an external source, such as the control element 18 of FIG. 1B. The active electrical element 30 may be further configured to change one or more drive states of the plurality of LEDs 28-1 to 28-3 based on the one or more stored operating states. In certain embodiments, the active electrical element 30 is configured to independently change the drive state of each LED of the plurality of LEDs 28-1 to 28-3 based on the plurality of operating states stored by the memory element. In this regard, the active electrical element 30 may be configured to receive and store one or more operating states and independently drive each LED of the plurality of LEDs 28-1 to 28-3 in accordance with the one or more operating states. The active electrical element 30 may continue to drive and maintain the operational state for each LED of the plurality of LEDs 28-1 through 28-3 until the active electrical element 30 receives a refreshed or updated signal corresponding to the updated operational state. In this manner, the active electrical element 30 may be configured to change the drive state of the plurality of LEDs 28-1 through 28-3 according to the temporarily stored operational state of the memory element. Thus, the plurality of LEDs 28-1 through 28-3 may be configured for active matrix addressing as described above.

[0040]

[0050] The active electrical element 30 may include a plurality of contact pads 38 to quickly receive one or more operating states for the plurality of LEDs 28-1 through 28-3. In certain embodiments, certain contact pads of the plurality of contact pads 38 are configured to receive one or more signals, and other contact pads of the plurality of contact pads 38 are configured to transmit signals to independently drive or address the plurality of LEDs 28-1 through 28-3. In certain embodiments, the active electrical element 30 comprises one or more of an integrated circuit chip, an ASIC, a microcontroller, or an FPGA. In certain embodiments, the active electrical element 30 may be configured to be programmable or reprogrammable after fabrication of the active electrical element 30 through various memory elements and logic incorporated within the active electrical element 30. In this regard, the active electrical element 30 may be considered programmable relative to embodiments in which the active electrical element 30 does not include an FPGA.

[0041]

[0051] The submount 32 can be formed from many different materials, with any suitable material being electrically insulating. Suitable materials include, but are not limited to, ceramic materials such as aluminum oxide, alumina, AlN, or organic insulators such as polyimide (PI) and polyphthalamide (PPA). In other embodiments, the submount 32 may comprise a PCB, glass, sapphire, Si, epoxy, silicone, or any other suitable material. For PCB embodiments, different types of PCBs may be used, such as standard FR-4 PCBs, bismaleimide triazine (BT) or related materials, metal-core PCBs, or any other type of PCB. In certain embodiments, the submount 32 includes an optically transparent material to allow light emitted from the plurality of LEDs 28-1 to 28-3 to pass through the submount 32. In this regard, the light-emitting surface of each of the plurality of LEDs 28-1 to 28-3 may be mounted to the submount 32. Suitable optically transparent materials for the submount 32 include glass, sapphire, epoxy, and silicone. In certain embodiments in which the submount 32 is an optically transmissive submount, the submount 32 may be referred to as a superstrate. The term “superstrate” is used herein to avoid confusion with other substrates that may be part of a semiconductor light emitting device, such as, for example, a growth or carrier substrate for an LED chip, or a different submount for the LED package 26. The term “superstrate” is not intended to limit the orientation, position, and / or configuration of the structure that “superstrate” describes. In certain embodiments, the submount 32 may comprise an optically transmissive superstrate, and the LED package 26 may not include another submount. In other embodiments, the submount 32 may comprise an optically transmissive superstrate, and the LED package 26 may comprise an additional submount, with multiple LEDs 28-1 to 28-3 disposed between the submount 32 and the additional submount.

[0042]

[0052] FIG. 2B is a cross-sectional view of the LED package 26 taken along the line AA in FIG. 2A. As shown, the LED 28-1 and the active electrical element 30 are mounted to separate portions of the first surface 32′ of the submount 32. Therefore, light emitted from the LED 28-1 may be configured to pass through the submount 32, with the second surface 32″ of the submount 32 configured as the primary light-emitting surface of the LED package 26. In particular, the anode contact 36-1 and the cathode contact 34-1 of the LED 28-1 are disposed on the opposite side of the submount 32 from the LED 28-1. In this regard, light emitted from the LED 28-1 can pass through the submount 32 and exit from the opposite surface 32″ without being affected by or absorbed by the anode contact 36-1 and the cathode contact 34-1. Additionally, contact pads 38 of the active electrical components may be positioned in a spaced-apart manner from first surface 32′ to provide all electrical connections in a spaced-apart manner from the primary emission surface, i.e., second surface 32″. While the cross-sectional view orientation in FIG. 2B is intended to illustrate configuring second surface 32″ of submount 32 as the primary light emission surface, the orientation of FIG. 2B and subsequent manufacturing cross-sectional views may be rotated 180 degrees so that LED 28-1 is sequentially assembled above submount 32 during intermediate manufacturing steps.

[0043]

[0053] 2C is a cross-sectional view of the LED package 26 of FIG. 2B during a subsequent manufacturing step that forms an encapsulation layer 40 and various electrical connections. The encapsulation layer 40 may be a blanket deposited over the LEDs 28-1 through 28-3 and the active electrical element 30, with the contact pads 38 and the cathode and anode contacts 36-1 and 34-1 accessible through the encapsulation layer 40. The encapsulation layer 40 may surround the outer or lateral edges of each LED of the LEDs 28-1 through 28-3, and the encapsulation layer 40 may also cover at least a portion of the bottom surface of each LED of the LEDs 28-1 through 28-3. The encapsulation layer 40 may surround the outer or lateral edges and the bottom surface of the active electrical element 30. For example, a removal step may then be applied to the encapsulation layer 40 to remove portions of the encapsulation layer 40 to form exposed surfaces for accessing the contact pads 38 and the cathode and anode contacts 36-1 and 34-1. The removal step may include a planarization process, such as grinding, lapping, or polishing.

[0044]

[0054] The encapsulating layer 40 may be applied or deposited by a coating or dispensing process. In certain embodiments, the encapsulating layer 40 may include one or more of silicone, epoxy, and thermoplastic materials such as polycarbonate, aliphatic urethane, or polyester, among others. The encapsulating layer 40 may be configured to modify or control the light output from the LEDs 28-1 to 28-3. For example, the encapsulating layer 40 may include an opaque or non-reflective material, such as a visible gray, dark, or black material, that can absorb some light propagating between the LEDs 28-1 to 28-3, thereby improving the contrast between the light emitted by the LEDs 28-1 to 28-3 through the submount 32. In certain embodiments, the encapsulating layer 40 may include light-absorbing particles suspended in a binder, such as silicone or epoxy. The light-absorbing particles may include at least one of carbon, silicon, pigment, or metal particles or nanoparticles. In certain embodiments, the light-absorbing particles comprise a predominantly black color, which provides a predominantly black or dark color to the encapsulating layer 40 when suspended in the binder. Depending on the desired application, the encapsulating layer 40 may be configured as transparent or light-transmitting, or the encapsulating layer 40 may include a light-reflecting or light-redirecting material, such as fused silica, fumed silica, or titanium dioxide (TiO) particles, which provide a predominantly white color to the encapsulating layer 40. Other particles or fillers may be used to improve the mechanical, thermal, optical, or electrical properties of the encapsulating layer 40. In certain embodiments, the encapsulating layer 40 may include multiple layers with different mechanical, thermal, optical, or electrical properties.

[0045]

[0055] Various electrically conductive traces 42 and vias 44 may be formed beneath the LEDs 28-1 to 28-3 and the active electrical element 30. For example, the electrically conductive traces 42 may be formed on the bottom surface of the encapsulation layer 40 and may be electrically coupled to various of the contact pads 38 and the cathode and anode contacts 36-1 and 34-1. The electrically conductive traces 42 and vias 44 may form a multi-layer structure that effectively routes electrical conduction paths between the active electrical element 30 and the LEDs 28-1 to 28-3. An additional encapsulation layer 46 may be provided, and specific ones of the electrically conductive traces 42 may be coupled to package bond pads 48-1 to 48-2 by specific ones of the vias 44. In this regard, the package bond pads 48-1 to 48-2 are configured to receive signals external to the LED package 26. In certain embodiments, package bond pads 48-1 to 48-2 are configured to mount to and bond to another surface (e.g., a mounting surface of an LED panel that includes electrical wiring or other types of signal lines) for receiving an external signal (e.g., from control element 18 in FIG. 1B).

[0046]

[0056] FIG. 2D is a simplified top view of the LED package 26 of FIG. 2C. The view shown by FIG. 2D is from the second surface 32″ of the submount 32 and represents the primary emission surface of the LED package 26. Accordingly, the plurality of LEDs 28-1 to 28-3 are configured below the submount 32 (e.g., an optically transmissive submount or optically transmissive superstrate) to provide emission light through the submount 32. The active electrical element 30 is also configured below the submount 32, and therefore all of the aforementioned electrical connections and electrical conduction paths are disposed below the active electrical element 30 and below the plurality of LEDs 28-1 to 28-3 relative to the second surface 32″. Thus, light generated by the plurality of LEDs 28-1 to 28-3 can pass through the submount 32 and exit from the second surface 32″ with reduced loss or absorption by the electrical connections, electrical conduction paths, or other elements within the LED package 26.

[0047]

[0057] FIG. 2E is a simplified bottom view of the LED package 26 of FIG. 2E. In operation, the bottom view illustrated by FIG. 2E depicts a primary mounting surface 50 of the LED package 26. In this regard, the LED package 26 is configured to be mounted to an exterior surface (e.g., a video display panel or PCB) such that package bond pads 48-1 through 48-4 are bonded or soldered to electrical communication lines provided on the exterior surface. In certain embodiments, at least one package bond pad 48-1 may include an identification feature 52, such as a notch, a different shape, or other form of identification feature, configured to communicate, for example, the polarity and mounting position of the LED package 26 on the exterior surface.

[0048]

[0058] FIG. 3 is a schematic block diagram of an LED package 54 and an integrated active electrical element 30 configured to process error detection codes in accordance with the principles of the present disclosure. The LED package 54 may be arranged with structures similar to the LED package 26 of FIGS. 2A-2E or with alternative structures. In certain embodiments, the LED package 54 forms an LED pixel for arrangement within a larger LED display. In this manner, the structure present in FIG. 3 may be present in each pixel of an active matrix display. The active electrical element 30 is configured to receive a power supply voltage (V dd ), ground (GND or V ss), and multiple ports represented by bidirectional communication ports or digital input / output ports (DIO1 and DIO2). By including the DIO1 and DIO2 ports as bidirectional communication ports, the active electrical element 30 may advantageously detect an input signal from a communication channel and then assign one of the DIO1 and DIO2 ports as an input port and the other of the DIO1 and DIO2 ports as an output port. This provides layout flexibility for displays in which multiple LED packages 54 are connected to each other for cascaded communication. For example, multiple LED packages 54 may be arranged in multiple rows, with data flowing in a serpentine manner from package to package along each row and from row to row. The V on the left side of the schematic dd In addition to the four ports GND, DIO1, and DIO2, active electrical element 30 includes four ports on the right side of the schematic diagram that are coupled to LEDs 28-1 through 28-3.

[0049]

[0059] Various elements of active electrical element 30 are described below, although it will be understood that active electrical element 30 may include many other components, including, among others, memory elements, signal conditioning elements, thermal management elements, electrostatic discharge elements, clock elements, and oscillators. In FIG. 3 , control logic 56 is configured to receive input data, execute commands according to a command protocol, provide control signals for operation of LEDs 28-1 through 28-3, report various voltage and / or temperature levels included with output data, and transmit the output data to the next adjacent LED package via the DIO1 and DIO2 ports. Control logic 56 may operate in the digital domain. Control logic 56 may include input / output buffers 58 (DIO0-1 in FIG. 3 ) electrically coupled to the DIO1 and DIO2 ports, with DI and DO pins of input / output buffer 58 accessible by control logic 56. Input / output buffer 58 is configured to assign input and output configurations to the bidirectional DIO1 and DIO2 ports.

[0050]

[0060] In certain embodiments, active electrical elements 30 may be configured to provide both forward and reverse bias states to LEDs 28-1 through 28-3. In this regard, control logic 56 may use appropriate active elements to control V dd The control logic 56 may include a reverse bias control output signal configured to provide a voltage level near V or near GND to the LEDs 28-1 to 28-3. The term "reverse bias" refers to a high level at the output of the control logic 56 creating a reverse bias condition, so the output signal may simply be coupled to an inverter 60 provided to the driver 62 of the active electrical element 30. Thus, the LEDs 28-1 to 28-3 may be forward biased or reverse biased depending on the particular operating conditions and / or commands received by the control logic 56. The inverter 60, or inverter logic element, may have output characteristics sufficient to drive the LEDs 28-1 to 28-3. The driver 62 may essentially be an analog interface of the active electrical element 30 electrically coupled to the control logic 56. The driver 62 may include controllable current sources 64-1 to 64-3, which may also be configured as LED sink drivers. V for each of the LEDs 28-1 to 28-3 may be configured to aid in voltage measurement when configured for reverse bias. ddPull-up resistors R1 through R3 may be incorporated to provide a path to the LEDs 28-1 through 28-3. Each of the current sources 64-1 through 64-3 may be electrically coupled to a digital output signal LED1 through LED3 of the control logic 56. The output signals LED1 through LED3 may be provided along multiple traces coupled to each of the current sources 64-1 through 64-3 for current selection purposes. The output signals LED1 through LED3 may embody PWM outputs of the control logic 56 for controlling the operation of the LEDs 28-1 through 28-3. The driver 62 may further include a multiplexer 66 electrically coupled to an analog-to-digital (ADC) converter and ADC selector of the control logic 56. Additionally, the driver 62 may include an on-chip temperature sensor provided through the multiplexer 66. In certain embodiments, the temperature sensor provides thermal compensation and / or thermal shutdown via a thermal compensation curve for the LEDs 28-1 through 28-3.

[0051]

[0061] As shown in FIG. 3 , the control logic 56 may include a command decoder 68, a CRC encoder 70, and a CRC decoder 72 configured to decode data blocks received from the communication channel. The CRC decoder 72 enables the active electrical element to verify an input error detection code, such as a CRC, received on the communication channel, and the CRC encoder 70 is configured to generate a new output CRC for output to the same and / or another communication channel. In certain embodiments, the LED package 54 can modify one or more portions of the received data and transmit the modified data to the next downstream LED package or other receiving element, such as a controller. When the LED package 54 modifies the data, the active electrical element 30 generates a new CRC via the CRC encoder 70 corresponding to the modified data. In examples where the active electrical element 30 detects errors using the input CRC, the CRC encoder 70 generates the correct code for the new data. However, if the received data is corrupted, it may be desirable to propagate the corrupted CRC to the output so that further downstream devices interpret the data as corrupted. In response, active electrical element 30 may generate a corrupted CRC, intentionally corrupted by CRC corruptor 73, to signal the corrupted data to other LED packages and other receiving elements. CRC corruptor 73 may be one of many common logic elements that generate a code guaranteed to be different from the correct code. One such example is a logic circuit designed to simply invert the last bit of the correct CRC code. While FIG. 3 is provided in the context of active electrical element 30 decoding and encoding a CRC, the same principles may be applied to any type of error detection code, and as a result, CRC encoder 70 and CRC decoder 72 may be referred to as an encoder and decoder, respectively.

[0052]

[0062] FIG. 4 is a block diagram 74 illustrating cascade communication for an LED package 76 in accordance with the principles of the present disclosure. The LED package 76 may embody any of the previously described LED packages of FIGS. 2A-2E and 3 configured as pixels in the display shown in FIG. 1A. Input communications from a data stream 78 on a communication channel are received by the LED package 76 and conveyed from input registers 80 to output registers 82, graphically depicted as boxes within the LED package 76. The input registers 80 and output registers 82 represent memory locations within the active electrical elements 30. The data stream may include data blocks of any length containing bits designated by the numbers 1, 2, 3, 4, . . . n, followed by a CRC. The data blocks may include command codes that are processed by the active electrical elements 30 of the LED package 76 (e.g., command decoder 68 of FIG. 3) to control the actions of the active electrical elements 30 and / or to control the operation of the LEDs within the LED package 76. 4 shows the CRC as an 8-bit CRC, the CRC may be of other lengths depending on the particular implementation. In yet further embodiments, the disclosed principles are applicable to any type of error detection code that follows a block of data for the purpose of at least partially validating the preceding data.

[0053]

[0063] During operation, each data bit of the data block and CRC code is sequentially received and held by the input register 80 during one clock cycle and then transmitted to the output register 82 with each clock cycle. In some examples, the data bits transmitted to the output register 82 are modified or altered based on the operation of the LED package 76. For example, a command code of the data block for operating a particular LED package 76 may be received and implemented, and the corresponding command code transmitted to the output register 82 may be altered to a code corresponding to information intended to be relayed back to the master controller for processing. In one such case, the LED package 76 receives brightness data and replaces it with temperature data for transmission back to the controller. When the data is modified by the LED package 76, the CRC encoder 70 of FIG. 3 may provide an updated CRC code to the output register 82 for transmission to the next LED package or other receiving element. Other portions of the data block may correspond to command codes for other LED packages downstream of the LED package 76 of FIG. 4 and may be transmitted through the LED package 76 without modification.

[0054]

[0064] When bit data is received at input register 80, it may be decoded by CRC decoder 72 of FIG. 3 and an expected CRC value may be calculated. The calculated CRC value may then be compared to the received CRC bit data to verify the data or identify corrupted data. If corrupted data is identified and LED package 76 does not modify any of the data, downstream LED packages may still be able to detect the corrupted data. However, if LED package 76 modifies data as described above, a newly generated CRC that takes into account the modified data may unintentionally correct a faulty CRC received from the data stream, making it impossible for downstream LED packages to identify corrupted data. In accordance with the principles of the present disclosure, LED package 76 and its embedded active electrical element 30 are configured with a CRC corrupter 73 to enable LED package 76 to identify data errors and intentionally generate a corrupted CRC code when LED package 76 modifies data. In this manner, LED package 76 can be configured to notify downstream LED packages of corrupted data even when it modifies data.

[0055]

[0065] FIG. 5 is a diagram 84 similar to FIG. 74, further illustrating the progression of data bits through the LED packages 76-1 to 76-3 after five clock cycles of cascaded communication. As shown, the bit positions of the data block and CRC can progress sequentially, shifting left to right through the input registers 80 and output registers 82 of the LED packages 76-1 to 76-3 according to the clock cycles. In this manner, the first bit position (i.e., “1”) of the data block may already be held in the input register 80 of the third LED package 76-3, while bit positions “2” and “3” are in the second LED package 76-2, bit positions “4” and “5” are in the first LED package 76-1, and the remaining bit positions have not yet been received by the LED packages 76-1 to 76-3. FIG. 5 shows boxes superimposed over the input registers 80 and output registers 82 to represent the data block as each bit position is currently distributed among the LED packages. The numbers in the input register 80 and output register 82 represent the bit positions of the first data block in this snapshot in time, which is the fifth clock cycle. During operation, the active electrical element 30 of the first LED package 76-1 cannot determine the validity of the data block until it processes the last bit position of the CRC code n+8 clock cycles later. Meanwhile, other bits of the CRC code, including the first few bits of the modified CRC code generated by the CRC encoder 70, may have already progressed through the second LED package 76-2 and the third LED package 76-3. For example, seven of the eight bit positions of the 8-bit CRC code have already illuminated the LED package 76-1 before determining that the data is corrupted in the eighth and final bit positions. In certain embodiments, upon receiving the last bit position of the CRC code and identifying corrupted data, the first LED package 76-1 can intentionally corrupt the last bit position (i.e., the CRC “8” in FIG. 5 ) when transmitting the last bit position to the output register 82.One technique for intentionally corrupting the last bit position of the CRC is to apply a bit inversion, or invert the value of the last bit position (i.e., change a 1 to a 0, or vice versa). Thus, even if a first LED package 76-1 modifies certain data and generates an updated CRC code, each of the downstream LED packages 76-2, 76-3 can correctly identify the corrupted data. In this case, receiving LED package 76-2 receives a block of data with the correct CRC, with its last bit inverted, to signal that the data is corrupted. The downstream LED packages 76-2, 76-3 may then be configured to independently modify the data, generate updated CRC codes, and intentionally corrupt the generated CRC codes when necessary.

[0056]

[0066] The exemplary embodiment described above for FIG. 5 illustrates one implementation that delays the data stream of the communication channel by two clock cycles for each LED package 76-1 through 76-3. Other embodiments with different delays are contemplated. For example, LED packages 76-1 through 76-3 may receive and interpret a larger portion of a data block, e.g., an entire 8-bit byte, and then transmit the larger portion of data to the next receiving element or downstream LED package after receiving the initial portion. In this manner, other embodiments of CRC corruptor 73 are contemplated, as there are many means known in the art for generating codes that differ from a given code.

[0057]

[0067] It is contemplated that any of the foregoing aspects, and / or various independent aspects and features described herein, may be combined to further advantage. Any of the various embodiments disclosed herein may be combined with one or more of the other disclosed embodiments, unless otherwise indicated herein.

[0058]

[0068] Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure, and all such improvements and modifications are considered to be within the scope of the concepts disclosed herein and the claims that follow.

Claims

1. 1. A light emitting diode (LED) package comprising: at least one LED chip; an active electrical element electrically connected to the at least one LED chip, the active electrical element comprising: receiving a data block and an input error detection code from a communications channel; modifying at least one portion of said data block; generating an output error detection code to replace the input error detection code, the output error detection code corresponding to the at least one portion of the data block that has been modified; an active electrical element configured to An LED package comprising:

2. 10. The LED package of claim 1, wherein the active electrical element comprises logic for providing the output error detection code as a corrupted output error detection code.

3. 2. The LED package of claim 1, wherein the active electrical element is configured to identify data corruption in the data block and provide the output error detection code as the corrupted output error detection code such that the data corruption is identified by another element configured to receive the corrupted output error detection code.

4. 4. The LED package of claim 3, wherein the active electrical element is configured to generate a calculated error detection code based on the data block and the at least one portion of the data block that was modified, and to invert a value of a last bit of the calculated error detection code to generate the corrupted output error detection code.

5. 2. The LED package of claim 1, wherein the input error detection code is an input cyclic redundancy check (CRC) and the output error detection code is an output CRC.

6. 6. The LED package of claim 5, wherein the active electrical element comprises: a CRC decoder configured to receive the input CRC; and a CRC encoder configured to generate the output CRC.

7. 10. The LED package of claim 1, wherein the active electrical element comprises a first bidirectional communication port and a second bidirectional communication port.

8. 8. The LED package of claim 7, wherein the active electrical element is configured to detect an input signal at the first bidirectional communication port, assign the first bidirectional communication port as an input port, and assign the second bidirectional communication port as an output port.

9. a submount on which the at least one LED chip and the active electrical element are mounted; an encapsulation layer on the submount and on the at least one LED chip and a portion of the active electrical element; a package bond pad electrically coupled to the at least one LED chip and the active electrical element; The LED package of claim 1 further comprising:

10. 1. A light emitting diode (LED) package comprising: at least one LED chip; an active electrical element electrically connected to the at least one LED chip, the active electrical element comprising: receiving an input error detection code from a communication channel; generating a corrupted output error detection code; transmitting said corrupted output error detection code along said communication channel or to another communication channel; an active electrical element configured to An LED package comprising:

11. 11. The LED package of claim 10, wherein the input error detection code is an input cyclic redundancy check (CRC) and the corrupted output error detection code is a corrupted output CRC.

12. 12. The LED package of claim 11, wherein the active electrical element further comprises: a CRC encoder; a CRC decoder; and a CRC corruptor that receives data blocks from the communication channel and identifies data corruption in the data blocks to generate the corrupted output CRC.

13. 13. The LED package of claim 12, wherein the active electrical element is further configured to modify at least a portion of the data block as it passes through the active electrical element, and to return the modified data block to the communication channel or the other communication channel to generate the corrupted output CRC.

14. 14. The LED package of claim 13, wherein the active electrical element is configured to generate a calculated CRC based on the input CRC and the at least one portion of the data block that was modified, and to invert a value of a last bit of the calculated CRC to generate the corrupted output CRC.

15. 11. The LED package of claim 10, wherein the active electrical element comprises a first bidirectional communication port and a second bidirectional communication port.

16. a submount on which the at least one LED chip and the active electrical element are mounted; an encapsulation layer on the submount and on the at least one LED chip and a portion of the active electrical component; a package bond pad electrically coupled to the at least one LED chip and the active electrical element; The LED package of claim 10 further comprising:

17. 1. A light emitting diode (LED) package comprising: at least one LED chip; an active electrical element electrically connected to the at least one LED chip, the active electrical element comprising: receiving an input error detection code from a communication channel; generating a calculated error detection code based on the input error detection code; inverting the last bit of said calculated error detection code to generate an output error detection code. an active electrical element configured to An LED package comprising:

18. 18. The LED package of claim 17, wherein the input error detection code is an input cyclic redundancy check (CRC), the calculated error detection code is a calculated CRC, and the output error detection code is an output CRC.

19. 20. The LED package of claim 18, wherein the active electrical element is configured to transmit the output CRC over the communication channel or over another communication channel.

20. 20. The LED package of claim 18, wherein the active electrical element is configured to receive a data block from the communication channel and identify data corruption in the data block to generate the output CRC.

21. 21. The LED package of claim 20, wherein the active electrical element is further configured to modify at least one portion of the data block that the active electrical element transmits to the communication channel or to another communication channel.

22. 20. The LED package of claim 17, wherein the active electrical element comprises a first bidirectional communication port and a second bidirectional communication port.

23. a submount on which the at least one LED chip and the active electrical element are mounted; an encapsulation layer on the submount and on the at least one LED chip and a portion of the active electrical component; a package bond pad electrically coupled to the at least one LED chip and the active electrical element; 20. The LED package of claim 17, further comprising:

Images