Patent Application
20120327047
1. Field of Art
The disclosure generally relates to an intra-panel interface of a display device. More specifically, the disclosure relates to a column driver with an embedded DISPLAYPORT timing controller and its system implementation.
2. Description of the Related Art
A typical pixel based display includes several column drivers. Each of the column drivers drives a group of pixels, often hundreds in the form of a column. The column drivers are able to drive any individual pixel through an output buffer circuit. A timing controller (TCON) is used to control the column drivers and display a desired image. The TCON processes communications received over a video link and transmits data to individual column drivers, but the interface between the TCON and column drivers can consume significant energy. Operation of a standalone TCON and related transmission functions typically accounts for a significant amount of power draw. A standalone TCON can also increase the size and cost of hardware used in the manufacturing of a display panel by using a chip separate from any of the column drivers.
The disclosed embodiments have other advantages and features which will be more readily apparent from the detailed description, the appended claims, and the accompanying figures (or drawings). A brief introduction of the figures is below.
The Figures (FIGS.) and the following description relate to preferred embodiments by way of illustration only. It should be noted that from the following discussion, alternative embodiments of the structures and methods disclosed herein will be readily recognized as viable alternatives that may be employed without departing from the principles of what is claimed.
Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying figures. It is noted that wherever practicable similar or like reference numbers may be used in the figures and may indicate similar or like functionality. The figures depict embodiments of the disclosed system (or method) for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein.
Various embodiments provide a system and method for embedding TCONs in the column drivers of a display. The disclosed system and method can decrease the power consumption and space used in display hardware. In an example embodiment, TCON functionality is embedded in each of the column drivers of a system. DISPLAYPORT is a high speed point to point interface protocol. The disclosed system embeds TCON functionality into each of the column drivers in a system while maintaining point to point capabilities to comply with the DISPLAYPORT specification. The timing controller processes video input and coordinates column drivers in a display to produce a desired image. In one embodiment, by embedding TCON functionality into the column drivers, chip real estate used in a display can be reduced. In addition, an interface such as reduced swing differential signaling (RSDS) can consume a significant amount of power transmitting signals from the standalone TCON, which is conventionally used rather than a power divider. This interface is eliminated by embedding the TCON on the column drivers. Although generally described for use in conjunction with DISPLAYPORT, systems utilizing other video standards including HDMI and DVI can benefit from the disclosed system and method. In addition to DISPLAYPORT, the disclosed system and method can be similarly utilized with EMBEDDED DISPLAYPORT for connections including those within a display panel interface.
Referring now to
The main link 102 is received by power divider 116. Power divider 116 distributes the main link 102 to each of the column drivers in the display panel, or in this case column driver 110 and column driver 112. The main link 102 signals distributed to each of the column drivers are near-identical signals. It should be noted that from a user's perspective, the display panel will use only a single input to receive a single video input as is typical, the signal may be split internally. The aux input 104 is received by column driver 110, which is designated as the master column driver. To allow communication between the external system 108 and non-master, or slave, column drivers, an auxiliary bus 130 is implemented. The auxiliary bus 130 allows the master column driver, column driver 110, to forward communications between the external system 108 and column driver 112. It should be noted that the system is expandable to include a plurality of column drivers. By utilizing the auxiliary bus 130, any number of column drivers can participate in link training, status report and other communications with the external system 108. Hence, point to point communication between the external system 108 and any of the column drivers is maintained. Slave column drivers can communicate with the external system 108 through the master column driver. In one embodiment, Inter-Integrated Circuit, or I2C, is used to facilitate communication between multiple column drivers over the auxiliary bus 130. Other communication protocols may be used to facilitate communication over the auxiliary bus 130. In one embodiment, each of the column drivers receives a signal on startup from a controller in the display panel designating whether it should use the auxiliary bus 130 as a master or a slave, though only a single column driver may be hardwired to receive auxiliary input 104 and serve as the master of the bus.
Turning next to
The display panel includes column drivers 310-315, power divider 316 and auxiliary bus 330. In one embodiment, the main link 302 provides a video signal allowing a display panel to receive and display video. The main link 302 is received by power divider 316. Power divider 316 distributes the main link 302 to each of the column drivers in the display panel. The aux 304 line allows communication between the display panel and an external system 308 outputting the video signal. This communication may include link training, status reports or other link establishing procedures. This communication may be designated for a certain column driver.
The aux input 304 is received by column driver 310, which is designated as the master column driver. To allow communication between the external system 308 and non- master, or slave, column drivers, an auxiliary bus 330 is implemented. The auxiliary bus 330 allows the master column driver, column driver 310, to respond to or forward communications between the external system 308 and column drivers 311, 312, 313, 314 and 315. It should be noted that any number of column drivers can utilize auxiliary bus 330. By utilizing the auxiliary bus 330, any number of column drivers can participate in link training, status report and other communications with the external system 308. In one embodiment, each of the column drivers receives a signal on startup from a controller in the display panel designating whether it should use the auxiliary bus 330 as a master or a slave. This may be particularly useful in a situation where multiple column drivers are wired to receive data from the aux 304 line.
The system and method described above enable mitigating the space and power consumption used in implementing TCON functionality for multiple column drivers. The video data is split and transmitted to each of the column drivers. An auxiliary link is used for communication between an external system and a master column driver. The master column driver responds to or forwards communications between the external system and column driver. Hence, each column driver is able to function independently utilizing an embedded TCON as described.
Throughout this specification, plural instances may implement components, operations, or structures described as a single instance. Although individual operations of one or more methods are illustrated and described as separate operations, one or more of the individual operations may be performed concurrently, and nothing requires that the operations be performed in the order illustrated. Structures and functionality presented as separate components in example configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements fall within the scope of the subject matter herein.
Certain embodiments are described herein as including logic or a number of components, modules, or mechanisms, for example, as described in
In various embodiments, a hardware module may be implemented mechanically or electronically. For example, a hardware module may comprise dedicated circuitry or logic that is permanently configured (e.g., as a special-purpose processor, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC)) to perform certain operations. A hardware module may also comprise programmable logic or circuitry (e.g., within a general-purpose processor or other programmable processor) that is temporarily configured by software to perform certain operations. It will be appreciated that the decision to implement a hardware module mechanically, in dedicated and permanently configured circuitry, or in temporarily configured circuitry (e.g., configured by software) may be driven by cost and time considerations.
The various operations of example methods described herein may be performed, at least partially, by one or more processors that are temporarily configured (e.g., by software) or permanently configured to perform the relevant operations. Whether temporarily or permanently configured, such processors may constitute processor-implemented modules that operate to perform one or more operations or functions. The modules referred to herein may, in some example embodiments, comprise processor-implemented modules.
Unless specifically stated otherwise, discussions herein using words such as “processing,” “computing,” “calculating,” “determining,” “presenting,” “displaying,” or the like may refer to actions or processes of a machine (e.g., a computer) that manipulates or transforms data represented as physical (e.g., electronic, magnetic, or optical) quantities within one or more memories (e.g., volatile memory, non-volatile memory, or a combination thereof), registers, or other machine components that receive, store, transmit, or display information.
As used herein any reference to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The phrase “in one embodiment” in various places in the specification is not necessarily all referring to the same embodiment.
Some embodiments may be described using the expression “coupled” and “connected” along with their derivatives. For example, some embodiments may be described using the term “coupled” to indicate that two or more elements are in direct physical or electrical contact. The term “coupled,” however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments are not limited in this context.
As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).
In addition, use of the “a” or “an” are employed to describe elements and components of the embodiments herein. This is done merely for convenience and to give a general sense of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.
Upon reading this disclosure, those of skill in the art will appreciate still additional alternative structural and functional designs for a system and method for embedding a timing controller on multiple column drivers through the disclosed principles herein. Thus, while particular embodiments and applications have been illustrated and described, it is to be understood that the disclosed embodiments are not limited to the precise construction and components disclosed herein. Various modifications, changes and variations, which will be apparent to those skilled in the art, may be made in the arrangement, operation and details of the method and apparatus disclosed herein without departing from the spirit and scope defined in the appended claims.
