Method and apparatus for controlling a video signal processing apparatus to prevent screen aging

An apparatus and method for controlling a video signal processing apparatus having a browser feature to protect a display device associated with the apparatus against the premature aging effects of screen burn due to an idle display when the browser feature is activated. The method includes the steps of detecting a first user input to a video apparatus, determining whether the first user input activates a browser feature of the video apparatus, and controlling the operation of the apparatus to reduce the screen burn. The operation can include setting a display parameter for the video apparatus to a first predetermined level responsive to determining that the first user input activates the browser feature, or determining an idle time and inactivating the browser feature if the idle time exceeds a predetermined period of time.

BACKGROUND OF THE INVENTION

The present invention generally relates to video apparatuses and a method for controlling video apparatuses, and more particularly, for controlling the operation of the video apparatus having a browser feature included therein to protect an associated display device against the premature aging effects of screen burn.

BRIEF SUMMARY OF THE INVENTION

With typical display screens utilizing one or more cathode ray tubes (CRTs) to provide a visual display, an unchanging image on the screen will tend to burn that image into the screen. In particular, a condition known as “screen burn” occurs when the phosphors on the internal surface of a CRT screen deteriorate over time due to the frequent presence of high-intensity beams necessary for creating an image. Those areas of the screen that continually receive more images will experience more screen burn than those areas of the screen that continually receive fewer images. Eventually, a noticeable difference may exist between different areas of the screen due to the accumulation of screen burn. In some cases, the burned-in screen image is very noticeable.

Video apparatuses such as television signal receivers typically provide video displays that are constantly changing over time, thereby reducing the chances of premature screen burn. However, with the inclusion of features such as an Internet browser into such apparatuses, display devices may be required to display images that have very little, if any, motion. As a result, the risk of screen burn increases. Accordingly, there is a need for a technique for preventing premature aging from screen burn in video apparatuses having a browser feature.

In accordance with an aspect of the present invention, a method for preventing screen aging is disclosed. According to an exemplary embodiment, the method comprises steps of detecting a first user input to a video apparatus, determining whether the first user input activates a browser feature of the video apparatus, and setting a display parameter for the video apparatus to a first predetermined level responsive to determining that the first user input activates the browser feature.

In accordance with another aspect of the present invention, a video apparatus for preventing screen aging is disclosed. According to an exemplary embodiment, the video apparatus comprises means for detecting a first user input to the video apparatus. Processing means determines whether the first user input activates a browser feature of the video apparatus. Deflection means sets a display parameter for the video apparatus to a first predetermined level responsive to the processing means determining that the first user input activates the browser feature.

Another aspect of the present invention is a method for mitigating screen burn or screen aging effects of the browser is to specify an “Idle timeout” such that if the user does not interact with the browser for a specified period, the browser will present a dialog warning box to the user informing him/her that if a browser command is not received in a short time period (30 seconds) the browser will automatically close and return the user to the program, or TV, viewing. After the specified time interval, the browser will terminate, close, and return the user to ‘normal’ (non-browser) TV viewing. The specification of “browser command” indicates that channel changes, volume changes, and “TV viewing” commands are different and distinct from browser commands. The method of entry into the browser dictates the “idle timeout” value. To wit: invocation of the browser from the menu will use a shorter timeout than via the keyboard command to invoke the browser.

As used herein, the term video apparatus includes any apparatus for processing video signals and providing output signals suitable for display on a display device, which may be externally attached or formed integrally with the apparatus, for example, a television receiver using cathode ray tubes and projection televisions including high definition television displays. The invention is especially useful in high definition apparatus, projection televisions, which are subject to such screen burn due to static images being displayed, and plasma displays. Although the exact amount of screen burn varies between different types and models of television displays and depends on the length of time a static image is displayed on the screen, and also varies according to user settings such as brightness and contrast, in general the high definition projection television type is the most prone to this problem.

The exemplifications set out herein illustrate preferred embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, and more particularly toFIG. 1, an exemplary apparatus100suitable for implementing the present invention is shown. For purposes of example and explanation, apparatus100represents an exemplary portion of a television signal receiver embodied as a projection screen television. However, it will be intuitive to those skilled in the art that principles of the present invention may be applied to other apparatuses.

As shown inFIG. 1, apparatus100comprises an audio/video input/output (AV IO) block101, a front audio/video (FAV) connector102, a digital processing block103, a front panel assembly (FPA)104, an infrared (IR) preamp105, an audio block106, a power supply107, a subwoofer amp/power supply108, a subwoofer109, a deflection block110, a convergence block111, CRTs112to114, and yokes115to117. The foregoing elements ofFIG. 1are operatively coupled as indicated by the data lines shown inFIG. 1. As will be intuitive to those skilled in the art, many of the elements represented inFIG. 1may be embodied using integrated circuits (ICs).

AV IO block101is operative to receive and process audio and/or video inputs, and to output processed audio and/or video signals to other elements of apparatus100, as indicated inFIG. 1. According to an exemplary embodiment, AV IO block101receives audio and/or video inputs from an external source (e.g., via satellite, terrestrial, cable, internet, etc.) and also receives processed audio inputs from audio block106. According to this exemplary embodiment, AV IO block101processes these inputs and outputs composite video signals and all audio signals to digital processing block103for additional processing, while outputting component video signals (e.g., 2H, 2.14H, Y, Pr, Pb video information) to deflection block110. FAV connector102is operative to provide audio and/or video inputs to AV IO block101.

Digital processing block103is operative to perform various digital functions of apparatus100, such as tuning, demodulation, signal decompression, memory and other functions. Although digital processing block103is illustratively shown as a single digital data processing block, it is well known that the functions performed within digital processing block103may be implemented using a plurality of well known IC blocks or units, including separate ICs for encoder/decoder, central processing or control, video signal processing, A/D conversion, D/A conversion, switching between auxiliary and main images for generating PIP images, etc. The techniques and methods for generating the various user-activated display functions, such as zoom, and various aspect ratio pictures, are well known to those skilled in the art and any such techniques and methods may be used in implementing the user-activated display function of the present invention. Also, digital processing block103may include sufficient memory to carry out certain functions, and be able to access and control external RAM and ROM (not shown) for carrying out the required video and data processing operations. As will be explained later herein, digital processing block103is also operative to enable a browser feature of apparatus100, and to enable a display parameter control function in response to detecting the activation and/or de-activation of the browser feature. As used herein, the “browser feature” of apparatus100refers to a feature, which enables users to access a network, such as the Internet.

FPA104includes an interface operative to receive user inputs. The user inputs may be received via known communications links in response to user operation of a remote control device, such as an IR hand-held remote control, a RF remote control device, a wireless keyboard, a wired remote control device, or other similar device. Upon receipt of the user input signals, FPA104provides the corresponding decoded control output signals to preamp105. Preamp105is operative to amplify the signals received from FPA104and provide the output to digital processing block103. Digital processing block103, which may incorporate central processing unit functions as noted above, receives the decoded control signals and performs various operations and controls apparatus100in response to the signals.

Audio block106is operative to perform various audio-processing functions, and to output processed audio signals. According to an exemplary embodiment, audio block106receives a center channel input signal and processes the same to generate audio output signals. As indicated inFIG. 1, audio block106is operative to provide audio output signals to both external and internal speakers of apparatus100. Additionally, audio block106provides audio output signals to AV IO block106, and also provides subwoofer audio signals to subwoofer amp/power supply108.

Power supply107is operative to receive an input alternating current power signal (AC-IN), and to output voltage signals which power the various elements of apparatus100, as indicated inFIG. 1. According to an exemplary embodiment, power supply107provides such voltage signals to AV IO block101, digital processing block103, audio block106, subwoofer amp/power supply108, and deflection block110. Subwoofer amp/power supply108is operative to amplify the subwoofer audio signals provided from audio block106, and provide the amplified subwoofer audio signals to subwoofer109. Subwoofer amp/power supply108also outputs a voltage signal to subwoofer109, which serves as its power supply. Subwoofer109is operative to aurally output the amplified subwoofer audio signals provided from subwoofer amp/power supply108.

Deflection block110is operative to control deflection functions of apparatus100. According to an exemplary embodiment, deflection block110outputs deflection control signals to yokes115to117, which control horizontal and vertical deflection of the high-intensity beams generated by CRTs112to114, respectively. Deflection block110is also operative to output color control signals to CRTs112to114responsive to the processed video signals and other control signals provided from digital processing block103. As will be explained later herein, the circuitry of deflection block110controls one or more display parameters of apparatus100responsive to digital processing block103detecting the activation and/or de-activation of a browser feature. Also according to an exemplary embodiment, deflection block110is operative to output voltage signals to convergence block111and CRTs112to114for their power supplies.

Convergence block111is operative to control convergence functions of apparatus100. According to an exemplary embodiment, convergence block111outputs convergence control signals to yokes115to117, as indicated inFIG. 1, which control a positive convergence adjustment for precisely focusing the high-intensity beams emitted from CRTs112to114on a screen (not shown).

CRTs112to114are operative to generate high-intensity red, green and blue beams, respectively, for display on a screen responsive to the color control signals from deflection block110. Yokes115to117are operative to control CRTs112to114, respectively, responsive to the deflection control signals from deflection block110and the convergence control signals from convergence block111.

Turning now toFIG. 2, a flowchart200illustrating exemplary steps according to one aspect of the present invention is shown. In particular,FIG. 2represents exemplary steps for changing the level of a display parameter of an apparatus from a predetermined normal level, or a user selected level, to a predetermined browser level when a browser feature of the apparatus is activated. For purposes of example and explanation, the steps ofFIG. 2will be described with reference to apparatus100ofFIG. 1. Accordingly, the steps ofFIG. 2are merely exemplary, and are not intended to limit the present invention in any manner.

At step201, a user input to apparatus100is detected. According to an exemplary embodiment, the user input to apparatus100is provided via an input device such as an IR hand-held remote control, keyboard, or the like. FPA104detects the user input and outputs a corresponding signal indicative of the input to IR preamp105, which amplifies the signal for output to digital processing block103.

At step202, a determination is made as to whether the user input at step201represents a command to activate the browser feature of apparatus100. As previously indicated herein, digital processing block103is operative to detect activation of the browser feature of apparatus100. Accordingly, at step202, digital processing block103examines the signal provided from IR preamp105to determine whether the user input represents a command to activate the browser feature of apparatus100.

The actual level of a display parameter used as the browser level is a matter of design choice, but should be selected to protect the display device associated with apparatus100against the premature aging effects of screen burn. According to one exemplary embodiment, the browser level may be set by the manufacturer of apparatus100and not be subject to adjustment by a user. With this embodiment, the specific level of a display parameter designated by the manufacturer as the browser level is always used at step203. For example, assuming the display parameter is contrast, the contrast level used as the browser level may be fixed at 50% contrast.

According to another exemplary embodiment, the browser level may be subject to adjustment by a user, but may have a maximum value set by the manufacturer. That is, the user may adjust the browser level upwardly and/or downwardly via inputs to apparatus100, but the actual level of a display parameter used as the browser level is capped at a fixed, maximum value. For example, assuming again that the display parameter is contrast, the browser level may have a maximum value of 50% contrast. According to this latter embodiment, the maximum value for the browser level may for example be set as a relative percentage of the current parameter level set by a user as part of the normal picture control settings of apparatus100. With contrast for example, if the normal picture control settings of apparatus100currently indicate 75% contrast, then the browser level may be capped at a relative percentage of this contrast level. Accordingly, if the relative percentage is 50%, then the browser level for apparatus100would be capped at 37.5% (i.e., 50% of 75%) contrast. Of course, other techniques for establishing the browser level may be employed according to the present invention.

Alternatively, when the determination at step202is negative, process flow advances to step204where the level of the display parameter for apparatus100is maintained at its current predetermined level, which may be referred to herein as the normal level. According to an exemplary embodiment, the normal level is the current level of the display parameter that is set by a user as part of the normal picture control settings of apparatus100.

After both steps203and204, process flow advances to step205where the algorithm is exited.

FIG. 3is a flowchart300illustrating exemplary steps according to another aspect of the present invention. In particular,FIG. 3represents exemplary steps for changing the level of a display parameter of an apparatus from the browser level to the normal level when the browser feature of the apparatus is de-activated. LikeFIG. 2, the steps ofFIG. 3will also be described with reference to apparatus100ofFIG. 1, and are not intended to limit the present invention in any manner.

At step301, a user input to apparatus100is detected. According to an exemplary embodiment, the user input to apparatus100is provided via an input device such as an IR hand-held remote control, keyboard, or the like. FPA104detects the user input and outputs a corresponding signal indicative of the input to IR preamp105, which amplifies the signal for output to digital processing block103for detection.

At step302, a determination is made as to whether the user input at step301represents a command to de-activate the browser feature of apparatus100. As previously indicated herein, digital processing block103is operative to detect de-activation of the browser feature of apparatus100. Accordingly, at step302, digital processing block103examines the signal provided from IR preamp105to determine whether the user input represents a command to de-activate the browser feature of apparatus100.

When the determination at step302is positive, process flow advances to step303where the level of the display parameter for apparatus100is set to the normal level. As previously indicated herein, the display parameter may be contrast, brightness, color level, sharpness, tint or another display parameter, and the normal level is the current level of the display parameter which is set by a user as part of the normal picture control settings of apparatus100.

According to an exemplary embodiment, digital processing block103outputs a control signal to deflection block110indicating that the browser feature is de-activated. Deflection block110responds to this control signal by adjusting one or more of its output signals, and thereby setting the display parameter for apparatus100to the predetermined normal level. For example, assuming the display parameter is color level, deflection block110adjusts the color control signals output to CRTs112to114to thereby set the color level for apparatus100to the predetermined normal level.

Alternatively, when the determination at step302is negative, process flow advances to step304where the level of the display parameter for apparatus100is maintained at its current predetermined level, which is the browser level.

After both steps303and304, process flow advances to step305where the algorithm is exited.

FIG. 4illustrates steps for exemplary steps according to another aspect of the present invention. According to another aspect, the video apparatus includes an idle timer that determines the period of time that the browser display is idle based on no user inputs being received, and if the idle timer exceeds a predetermined period of time, the browser display is inactivated and the apparatus reverts to display of program signals, i.e., television signals. The predetermined period of time may be set according to the manner in which the browser feature is activated. For example, if the predetermined idle period may be set for one period if the browser is activated by user activation of a dedicated key on a keyboard, and for another period fir the browser is activated by user navigation of an on-screen display. It may be useful to set a longer idle period for the former case than the latter because it is likely that a user activating a browser with a keyboard is likely to be more actively utilizing the browser display.

In step402, a user input is detected. If the user input is determined to be a browser activation command in step404, the process continues to step408where the processing unit103generates the signals for displaying a browser. If not, the process continues at step406and display the selected program signal. When the browser feature is activated, the process determines the idle period in step410. The idle period may be fixed at the time manufacture, be set based on the source of browser activation, as mentioned above, or be set by the user utilizing a set up menu of apparatus100.

At step412, the idle timer is activated or is reset, and begins counting. Process400then waits for the receipt of the next user input in step414. When the user input is received, the process determines in step416whether the user input was received prior to the expiration of the idle timer period. If so, the process continues the display of the browser in step420and returns to reset the idle timer in step412and begins counting and waiting for the next user input. If the user input is not received before the expiration of the idle time period, process400switches the display to inactivate the browser display and provide program signal display in step418. Obviously, the process need not wait until a user input is received before switching the displays in step418. Namely, the process switches the displays as soon as the idle time period expires. In an alternative embodiment, the operation of process400may depend upon the type of user input that is received. For example, in step414, process400may be arranged such that the status of the idle timer is checked if the user input is a “browser command” that results in a change in the content of the display. On the other hand, if the user input is a “program viewing command,” which may comprise commands that do not change the content of the browser display, process400ignores the command and continues the idle timer. In this manner, only those user inputs that result in a change in the content of the display prevents the display from reverting to the program signal display.

As described herein, the present invention advantageously controls one or more display parameters in a video apparatus having a browser feature in order to protect a display device against the premature aging effects of screen burn. While an exemplary embodiment of the present invention has been described wherein a single display parameter is controlled responsive to browser activation and/or de-activation, it is anticipated that a combination of such parameters may also be controlled.

The present invention is particularly applicable to various video signal-processing apparatuses, either with or without a display device. Accordingly, the phrases “video apparatus” or “television signal receiver” as used herein may refer to systems or apparatuses including, but not limited to, television sets, computers or monitors that include a display device, and systems or apparatuses such as set-top boxes, video cassette recorders (VCRs), digital versatile disk (DVD) players, video game boxes, personal video recorders (PVRs), computers or other apparatuses that may not include a display device.