Patent Grant
9053673
1. Field of Art
The disclosure generally relates to an intra-panel interface of a display device.
2. Description of the Related Art
A typical pixel based display includes numerous source drivers that drive a group of pixels, often a row or a column. Through multiplexing, the source drivers are able to drive any individual pixel through a unique combination of voltage source and sink. A time controller (TCON) is used to control the source drivers and display a desired image. The interface between the TCON and source drivers allows the TCON to transmit data to individual source drivers, but lacks the ability for significant communication from a source driver to the TCON. For example, to find an error in a display, the display is usually visually examined to locate unwanted visual artifacts. Source drivers are unable to report to the TCON that a transmission was not properly received from the TCON or when an error occurs during normal operation.
Many methods for communication between TCON and source drivers explicitly transmit a clock separately from data. Inclusion of this clock can cause electromagnetic interference. Additionally, existing voltage drivers used in transmitting data from a TCON to a source driver are powered by two separate rails. Such a configuration increases the size and cost of hardware needed in an intra-panel interface between TCON and source driver.
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.
Configuration Overview
Various embodiments provide a system and method for implementing an intra-panel interface. The disclosed system and method can decrease the cost of such an intra-panel interface and enhance the level of feedback and control available to system designers. In an example embodiment, an intra-panel interface enables communication between a time controller and a plurality of source drivers. The interface provides benefits which may include reduced bus width allowing smaller board and connectors, low EMI generation, low power consumption, symbol error monitoring at source drivers and scalable high throughput. Although generally described for use in conjunction with LCD based displays, the described method is also applicable to any pixel-based display or a display with a similar configuration such as plasma based displays.
Referring now to
The time controller 110 is communicatively coupled to each of the source drivers 120. The time controller 110 transmits data to source drivers 120 via data channels 130 and source drivers 120 transmit data to the time controller 110 via ASC 132. In one embodiment, data channels 130 are DC-coupled differential pairs with double termination. The number of data channels for communication between the TCON 110 and a source driver 120 is scalable. The number of data channels can be selected to satisfy the maximum transmission throughput used for a specific implementation. The maximum transmission throughput of a single channel is primarily limited by channel conditions between the TCON 110 and source driver 120. These conditions can include distance, quality of material and signal noise. A clock is not explicitly sent from TCON 110 to any of the source drivers 120 when communicating through data channels 130. Instead, the clock is recovered from packets by the source drivers 120 based on initialization data received from TCON 110.
The ASC 132 is a one line communication channel and enables the source drivers 120 to provide status information, for example, symbol lock status or symbol error count, to the TCON 110. The ASC is shared by multiple source drivers 120 through multi-drop configuration. This allows a reduction in area and signal line used for a plurality of source drivers 120 to communicate with the TCON 110. In one embodiment, a single ASC 132 is connected to all of the source drivers 120 in the system and the ASC 132 is connected to a single TCON 110. In another embodiment, multiple ASC 132 may be used with each ASC 132 connected to a subset of source drivers 120. In addition, multiple time controllers may be used to communicate with source drivers through data channels and multiple ASC.
The ASC 132 is used to indicate a source driver symbol lock. If not properly initialized, a source driver 120 will set ASC 132 low. Due to the multi-drop configuration, the ASC 132 will appear low unless all source drivers connected to the ASC 132 pull ASC 132 high. Therefore, TCON 110 knows that initialization has not been completed unless ASC 132 appears high. In addition, source drivers 120 can also transmit a error reports to TCON 110 over ASC 132. Error reports can include both bit error rate and symbol error reports. Source drivers 120 can transmit data over ASC 132 while continuing to receive display data from TCON 110 and properly controlling a display panel. A link symbol error report is sent in response to a request from TCON 110. The request for a link symbol error report is included in the data packets transmitted from TCON 110 to source drivers 120. A error report request from TCON 110 can only be transmitted when ASC 132 is high indicating that all coupled source drivers 120 have symbol lock. The TCON 110 can identify loss of symbol lock by observing that ASC 132 is low for at least a predetermined amount of time. This allows a source driver to transmit data to TCON 110 by controlling ASC 132, as long as ASC 132 is not left low for at least the predetermined amount of time. Source drivers contain a volatile or non-volatile memory to store the number of symbol errors that have occurred. In one embodiment, source drivers store a 16-bit symbol error counter. Source drivers 120 can check if data received from TCON 110 is valid and increment an error counter if data is invalid. Source drivers 120 can report the number of errors that have occurred to TCON 110 and reset the error counter in response to a request from TCON 110. Symbol error data and bit error count data can be recorded by individual source drivers 120. This information can later be reported to TCON 110 via ASC 132 when a request is sent from TCON 110 to a source driver 120.
TCON 110 sends a request for a symbol error report only when the ASC 132 is high. This indicates that all source drivers 120 are operating normally and able to receive and reply to transmissions. TCON 110 can send a symbol error request to only a single source driver that is connected to a shared ASC line at a time. All source drivers 120 connected to ASC 132 share the same line, and therefore, only a single source driver can fully control it at any point in time. After receiving a symbol error report from a first source driver, TCON 110 can send a request to another source driver.
The type of transmission that can be sent over ASC 132 from a source driver is limited by the fact that ASC 132 indicates that all source drivers 120 are properly initialized. In one embodiment, TCON 110 begins initialization whenever ASC is pulled low by one or more source drivers 120 for a full cycle. This allows data to be transmitted over ASC 132 as long as ASC is kept high for at least part of the cycle. To accomplish this, a coding scheme such as Manchester II is used which transitions from high to low or low to high in each cycle. Utilizing such a coding scheme, data can be transmitted without leaving ASC 132 low for a full cycle and causing initialization to begin. If a source driver does lose symbol lock or is unable to recover clock in transmissions from TCON 110, that source driver can override any transmission taking place on ASC 132 and pull the line low for a full cycle to trigger the initialization process at TCON 110.
Turning next to
If 207 ASC is high, TCON 110 transmits 209 a second training pattern. In one embodiment, TCON 110 transmits ten consecutive K28.5 patterns to verify a symbol lock. TCON 110 again checks 211 that the ASC is high. If any source driver 120 detects a symbol error, the ASC will be pulled low. If ASC is pulled low, TCON returns to step 205 and again transmits training pattern 1. In another embodiment, TCON 110 may return to 209 and transmit training pattern 2. If 211 ASC is set high, TCON 110 enters 213 a normal operation state. If PLL lock is lost at any time during link training or normal operation, TCON 110 returns to the initialization step 201 and attempts to reestablish PLL lock. During normal operation, TCON 110 sends data packets to the source drivers 120 as long as ASC remains high. If ASC becomes low unexpectedly, TCON returns to step 205 to being link training once again.
Next,
After setting the ASC high, source driver 120 attempts to receive 307 training pattern 2, such as a K28.5 symbol. If any error is detected in receiving training pattern 2, the ASC is set low to notify TCON 110 of the error(s) and source driver 120 returns to step 300. If 309 training pattern 2 is detected and no errors occur, source driver 120 enters a state of normal operation 311. In another example embodiment, source driver 120 may receive fewer or more training patterns before entering a state of normal operation. In normal operation, the source driver decodes and acts upon display packets received from TCON 110. Display packets may include instructions related to driving a group of pixels, configuration data or requests for data from TCON 110. In one embodiment, source driver 120 sets ASC low if it is unable to perform clock recovery or the amount of symbol errors reach a certain threshold.
Turning to
Clock and data recovery is performed at each of the source drivers 120 to interpret transmissions from TCON 110. In one embodiment, an 8b/10b encoding scheme is utilized to transfer data from TCON 110 to source drivers 120. Upon receiving data, the data may be re-arranged by the source drivers 120 to decode the proper data for a specific color component to be displayed.
Referring now to
Next,
In one embodiment, FPC 815 is placed between and in contact with both the PCB 802 and panel 803. Multiple FPC can be used to transmit data to a plurality of source drivers. In one embodiment, each FPC transmits data from a TCON to a subset of source drivers. In addition, subsets of source drivers may all use the same ASC 832 or subsets can be assigned separate ASC lines.
The system and method described above enable enhanced reliability in an intra-panel communication interface, such as the interface between a TCON and source drivers. The TCON is able to receive accurate and up to date error information from the source drivers and take action to minimize the number of errors occurring. By using a single ASC line to transmit information from a plurality of source drivers, the area needed for and cost of connectors are reduced. Additionally, the intra-panel interface features scalability allowing integration with high resolution displays by increasing number of data channels between the TCON and source driver.
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. Modules may constitute either software modules (e.g., code embodied on a machine-readable medium or in a transmission signal) or hardware modules. A hardware module is tangible unit capable of performing certain operations and may be configured or arranged in a certain manner. In example embodiments, one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware modules of a computer system (e.g., a processor or a group of processors) may be configured by software (e.g., an application or application portion) as a hardware module that operates to perform certain operations as described herein.
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.
Some portions of this specification are presented in terms of algorithms or symbolic representations of operations on data stored as bits or binary digital signals within a machine memory (e.g., a computer memory). These algorithms or symbolic representations are examples of techniques used by those of ordinary skill in the data processing arts to convey the substance of their work to others skilled in the art. As used herein, an “algorithm” is a self-consistent sequence of operations or similar processing leading to a desired result. In this context, algorithms and operations involve physical manipulation of physical quantities. Typically, but not necessarily, such quantities may take the form of electrical, magnetic, or optical signals capable of being stored, accessed, transferred, combined, compared, or otherwise manipulated by a machine. It is convenient at times, principally for reasons of common usage, to refer to such signals using words such as “data,” “content,” “bits,” “values,” “elements,” “symbols,” “characters,” “terms,” “numbers,” “numerals,” or the like. These words, however, are merely convenient labels and are to be associated with appropriate physical quantities.
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 enabling enhanced reliability in an intra-panel communication interface 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.
| Number | Name | Date | Kind |
|---|---|---|---|
| 6300928 | Kim | Oct 2001 | B1 |
| 7893912 | Kim | Feb 2011 | B2 |
| 7898518 | Hong et al. | Mar 2011 | B2 |
| 7936330 | Park et al. | May 2011 | B2 |
| 7948465 | Cho et al. | May 2011 | B2 |
| 8212803 | Hong et al. | Jul 2012 | B2 |
| 8884934 | Jeon et al. | Nov 2014 | B2 |
| 8907939 | Liu et al. | Dec 2014 | B2 |
| 8947412 | Jeon et al. | Feb 2015 | B2 |
| 20040221056 | Kobayashi | Nov 2004 | A1 |
| 20040233181 | Kobayashi | Nov 2004 | A1 |
| 20050062699 | Kobayashi | Mar 2005 | A1 |
| 20050062711 | Kobayashi | Mar 2005 | A1 |
| 20050066085 | Kobayashi | Mar 2005 | A1 |
| 20090244052 | Takahashi | Oct 2009 | A1 |
| 20100225637 | Jeon et al. | Sep 2010 | A1 |
| 20100289945 | Kobayashi et al. | Nov 2010 | A1 |
| 20110157103 | Chen et al. | Jun 2011 | A1 |
| 20120056857 | Li et al. | Mar 2012 | A1 |
| 20120056870 | Koh | Mar 2012 | A1 |
| Number | Date | Country |
|---|---|---|
| 200729122 | Aug 2007 | TW |
| 201040911 | Nov 2010 | TW |
| 201102990 | Jan 2011 | TW |
| WO 2010131843 | Nov 2010 | WO |
| Entry |
|---|
| Korean Office Action, Korean Application No. 10-2012-0065984, Oct. 22, 2013, 8 pages. |
| Korean Office Action, Korean Application No. 10-2012-0065984, Jul. 24, 2014, 15 pages. |
| Taiwan Office Action, Taiwan Application No. 101122275, Mar. 21, 2014, 12 pages. |
| Number | Date | Country | |
|---|---|---|---|
| 20120242628 A1 | Sep 2012 | US |
