Controlling text symbol display size on a display using a remote control device

Described is a solution for controlling text symbol size on a display of a display unit based on a measurement of the distance between a remote control device and the display unit. A distance sensing module provides a distance measurement based upon detection of a transmitted signal from the remote control device. A symbol size calculation module determines a target symbol height based on the distance measurement, and a symbol size adjustment module adjusts the size of symbolic content on the display preferably using animation.

BACKGROUND

The invention generally relates to controlling text symbol size on a display.

Text symbols are symbols which are represented by in digital text representation formats. Some examples are alphanumeric characters, numerals, punctuations, arrows and circles typically found in menus, and special characters such as mathematical symbols, the ampersand (&), the dollar sign ($), the registered trademark sign (®) and the atsign (@).

Menus provided by set-top boxes include text symbols. Additionally, more and more television content includes displayed overlays, some examples of which are tickers, sports scores, and background information about a show. In the context of a digital set-top box, the text symbols representing this content can be displayed at a default size for all presentations. A viewer having trouble seeing symbols clearly must leave the show with the overlay or the menu and navigate to another menu for changing symbol size in order to select another size from a set of limited choices (if this option is even available). This selected size will then be the size for all text subsequently displayed until changed via the text size menu.

Controlling text symbol display size responsive to a distance from a remote control to a sensor on a display unit for the display, or on a set-top box connected to the display and approximately the same distance as the display to the viewer's position (e.g. less than a foot in front or in back of the display)) would be more user friendly by allowing a viewer to adjust symbol size without leaving the context of a show or menu. This mechanism also allows the viewer to enlarge or decrease the size of the currently displayed text momentarily (e.g. the World Series scores) and then decrease or enlarge the next displayed text (e.g. the hockey scores) back to the previous size if desired.

SUMMARY

The present invention provides one or more solutions for controlling text symbol display size on a display of a display unit responsive to a distance of a remote control device from the display unit in accordance with one or more embodiments of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1Aillustrates an example context100of a viewer (Viewer A) watching television. A system117for controlling text symbol display size on the display110responsive to a distance of a remote control device102from the display unit114allows the viewer to adjust the text symbol display size with his remote control102in accordance with an embodiment of the present invention.FIG. 1Aillustrates a display unit114including a television display110in a supporting encasement116. In this embodiment, the display unit114includes as part of the system117a symbol size adjustment system115and part of a distance sensing system111which is communicatively coupled to provide at least one digital output value representing a distance measurement from the remote control102to the display unit114to the symbol size adjustment system115which is communicatively coupled to a display module206which controls the presentation of content on the display110.

In this embodiment, the distance sensing system111includes a transmitter104on the remote control device102for generating a light signal, a detector lens106which focuses a received signal from the transmitter104onto a sensor108which provides an analog output signal to analog-to-digital converter109for a digital output value usable by the symbol size adjustment system115. In one example, the transmitter104is an infrared light emitting diode (LED) that projects a spot of modulated light onto the detector lens106which focuses the spot of light onto a linear position-sensitive detector element108. Depending on the distance from the remote control102to the detector lens106, the angle of the incoming reflected light will change, and the spot of light is projected to a different point along the position sensor108. Thus, the location of the spot on the sensor corresponds to a distance to the remote control device102.

FIG. 1Aillustrates just one example of a distance sensing system111. In other examples, the transmitter104is the transmitter used ordinarily for remote control functions such as volume control and channel switching. In another example, a radio frequency signal transmitter can be used. In another example, the transmitter104and the sensor108can both be on the remote control device102in which a distance measurement is based on a return signal bounced off the glass or plastic of the display110and is communicated as data to a remote control receiver unit118which in turn sends the data to the symbol size adjustment module115in the display unit114. Other distance sensing systems can also be used that base measurement on another characteristic, some examples of which are those that use sound, timing or phase shift.

Three reference distances are represented by the lines labeled d1and d2. The distance d1represents the distance from the remote control device102to the portion of the distance sensing system111in the set-top box112as represented by one or more digital output values from the distance sensing system111. The distance d2is a pre-configured amount representing the viewing distance from Viewer A's eyes to the remote control device102which is added as an offset to d1for representing the total distance from Viewer A's eyes to the display110. The height d3represents the symbol height desired for the viewing distance (d1+d2) and can be calculated from the equation d3=2*(d1+d2)*tan(f/2) where f is a desired visual angle to subtend. For example, if the symbol height is to subtend an angle equal to a human fovea (2 degrees or 0.035 radians), and the total distance from Viewer A's eyes to the display110is determined to be ten (10) feet (d1+d2=10) then the symbol height d3=20 tan(0.035/2)=0.35 feet or approximately 4 inches. The human foveal visual angle is between 1 and 2 degrees. The calculation derives from a right triangle formed by (d1+d2) as the adjacent leg which bisects the viewer's foveal angle f by 2, thus making f/2 the angle to which one half of the desired symbol height d3is the opposite leg. From the end of this opposite leg that is not perpendicular to (d1+d2), the hypothenuse leg extends back to the viewer's eye.

FIG. 1Billustrates another example context1002of another embodiment of a system117for controlling text symbol size on a display110of a display unit1142responsive to a distance of a remote control device from the display unit1142in accordance with another embodiment of the present invention. In this example, the display unit1142includes a set-top box112which includes the system117including at least a part of the distance sensing unit111and the symbol size adjustment module115. In a display unit1142including a separate set-top box, an example of which is a cable box or a digital video recorder (DVR), viewers tend to place a set-top box in the same vertical line with a television screen and the remote control reception units tend to be almost in the same vertical line and with a horizontal offset of a few inches generally. Thus, a distance sensing system111in a set-top box or other processor controlled unit which is typically located underneath or on top of the display (111). The distance sensing system111thus provides a sensed distance that is a close approximation to the distance between the remote control device102and the display110.

FIG. 2Ais an architectural block diagram of a system117for controlling text symbol display size on a display of a display unit responsive to a distance of a remote control device from the display unit in accordance with an embodiment of the present invention. The system117comprises a processor204communicatively coupled to receive digital output from the distance sensing system111, and also communicatively coupled to a user interface208for processing commands from the remote control device102(e.g. channel up, volume down, next selection in a menu, etc.). The processor204is accessible to a memory210, and is communicatively coupled to a display module206for controlling the display device110.

The memory210includes a symbol size calculation software module212for calculating a target text symbol height, and a symbolic display content storage module214for text symbolic content which can be displayed (e.g., a display overlap of local weather conditions for a content selection or a menu), and a symbol definition module215including definitions for text symbols. An example of a definition for a text symbol is a vector graphic representation representing a typeface which can be scaled to a font size, for example a point size, within a range by outline font software (e.g., TrueType and Adobe's Type 1). Another example of a definition for a text symbol is a bitmap font which is a digital representation of a font that is already fixed in size or has a limited set of sizes.

The memory210further includes a configuration settings storage module216including one or more predetermined values for d2as well as other information related to displaying changing symbol sizes, some examples of which can be a rendering speed of the display module206, and resolution of the display (e.g.,110), and a symbol size adjustment module222which adjusts symbol size to a target symbol size corresponding to the calculated symbol height. The symbol size adjustment module222can use the display-related information stored in the configuration settings storage module216to determine which transition effect (e.g., animation, fade in fade out) can be supported when changing the symbol size.

FIG. 2Bis an alternate embodiment of the system embodiment117inFIG. 2Ain that the memory210further includes a lookup table218for mapping a determined symbol height d3to a tiered symbol size within a set of predetermined symbol sizes. For example, a determined text symbol height can be within a range which maps into one of a set of predetermined text symbol sizes. An example of such a set of predetermined text symbol sizes would be small, medium and large sizes.

FIG. 3is a functional block diagram of a system117for controlling text symbol display size on a display of a display unit responsive to a distance of a remote control device from the display unit in accordance with an embodiment of the present invention. The symbol size calculation module212is communicatively coupled to receive one or more digital output values from the distance sensing system111. Each digital output value corresponds to a distance measurement between a viewer of the display and the display unit. The symbol size calculation module212determines a symbol height based on the one or more distance measurements. An example calculation that can be used to determine the text symbol height is illustrate below:
d3=2*(d1+d2)*tan(f/2) in whichd3: symbol heightd1: distance from remote control device to the distance sensing systemd2: distance estimate from viewer's eyes to remote control devicef: visual angle to subtend equal to about human fovea angle which is between 1 and 2 degrees.
Using this calculation in the embodiment ofFIG. 3, the symbol size calculation module212has access to the configuration settings storage module216for retrieving a value, d2, representing an estimate of the distance of the remote control from the viewer's eyes to the remote control device102for use in determining a text symbol height size.

The symbol size calculation module212is communicatively coupled to send the calculated symbol height d3to the symbol size adjustment module222which selects a symbol size based on the symbol height. A typical standard for representing the size of a symbol is a font size which is typically stated as a number of points. For each style of font, the font size for each point size height has a predefined width, so once the symbol size calculation module212determines a height, the symbol size adjustment module222selects the nearest font size for that point size for the style of the symbolic content for display accessible via symbolic display content storage module. The symbol size adjustment module222has access to the configuration settings module216for display specific information such as the resolution and the rendering speed of the display module206. The symbol size adjustment module222adjusts the font size of the symbol content for display, for example, by adjusting an associated font size in its meta-data, and sends a version of the symbol content with the adjusted symbol size to the display module206for rendering on the display device110.

Each of the modules illustrated inFIG. 3or a portion thereof can be implemented in software suitable for execution on a processor and storage in a computer-usable medium, hardware, firmware or any combination of these. Computer-usable media include any configuration or medium capable of storing or transferring programming, data, or other digital information. Examples of computer-usable media include a data transmission as well as various memory embodiments such as random access memory and read only memory, which can take a variety of forms, some examples of which are a hard disk, a disk, flash memory, or a memory stick.

FIG. 4is a flow diagram of a method for controlling text symbol display size on a display of a display unit responsive to a distance of a remote control device from the display unit in accordance with an embodiment of the present invention. For illustrative purposes only and not to be limiting thereof, the method embodiment400ofFIG. 4is discussed in the context of the system300ofFIG. 3. The symbol size calculation module212receives402one or more digital output values, each digital output value corresponding to a distance measurement between a viewer and a display unit (e.g.114), and determines404a symbol height based on the one or more distance measurements, and the symbol size adjustment module222adjusts406the symbol size of text content on the display110based on the determined symbol height.

FIG. 5is a flow diagram of a method500for controlling text symbol display size on a display of a display unit responsive to a distance of a remote control device from the display unit in accordance with another embodiment of the present invention. For illustrative purposes only and not to be limiting thereof, the method embodiment500ofFIG. 5is discussed in the context of the system300ofFIG. 3. In this embodiment, the symbol size calculation module212performs the symbol size calculation based on an average of distance d1measurements from the remote sensing unit111received over a time period, a window. The symbol size calculation module212receives502a distance measurement for d1, stores504the distance measurement for d1and determines506whether the current window time is still less than the time period of the averaging window. Responsive to a positive determination, the symbol size calculation module212performs acts502,504and506for another distance measurement for d1, until the result from the calculation module's212determination506is that the current window time has met or exceeded the average window time period. Responsive to this result, the symbol size calculation module212sets508current distance d1to the average of the stored distance measurements for d1for the current window time.

The size calculation module212determines510whether the current distance d1is within a distance change threshold of distance d1. A distance change threshold is a predetermined distance delta amount that if not exceeded does not warrant a change in the symbol size. If the distance change is determined510to be within the threshold, the calculation module212starts518a new averaging window time period and repeats processing502,504,506for the distance measurements falling within the new averaging window. If the calculation module212determines the current distance d1is not within the distance change threshold, the symbol size calculation module sets512the current distance d1to be distance d1, determines514a target symbol height based on distance d1, distance d2and the fovea subtending angle f, adjusts516a symbol size for text symbol content on a display based on the target symbol height, and starts518a new averaging window for processing of subsequent distance d1measurements. Thus, if the user suddenly moves closer, then the distance suddenly changes by an amount greater than the pre-configured threshold, causing the symbol size to change.

FIG. 6is a flow diagram of a method for controlling text symbol display size on a display of a display unit through manual fine adjustment in accordance with another embodiment of the present invention. For illustrative purposes only and not to be limiting thereof, the method embodiment600ofFIG. 6is discussed in the context of the system300ofFIG. 3. From the user interface module204, the symbol size adjustment module222can receive an indicator for a fine adjustment mode for adjusting symbol size. In one example, a sensor (e.g., a thermal sensor, a pressure sensor, or a motion sensor) can detect that the remote control is being held so that a smaller range of movement of the remote control device causes size adjustment within a symbol size range. In another example, a fine adjustment mode indicator is user input indicating a key is being held down and movement of a certain distance of the remote control in the forward direction can cause an increment or decrement depending on the selected protocol of the symbol size. Similarly, backward motion of the remote control can cause an increment or decrement depending on the selected protocol of the symbol size. In yet another example, a key on the remote control can be selected to enter a manual fine adjustment mode, and up down or left right arrows signals from arrow buttons or channel up/channel down or volume up/volume down buttons can be received by the remote control receiver unit118and sent to the symbol size adjustment module115for processing to determine in which direction to increment or decrement the symbol size.

The symbol size adjustment module222receives602a fine adjustment mode entry indicator receives and determines604whether a directional symbol size change request has been received. If no such request has been received, the adjustment module222determines606whether an exit fine adjustment mode indicator has been received. An exit fine adjustment mode indicator could be user input pressing the manual mode to exit it or a timeout period in which no remote control selector activations are indicated. If the an exit fine adjustment mode indicator has been received, the symbol size adjustment module222transitions608back to a regular distance adjustment mode which performs activity such as that described inFIG. 5. If the exit mode indicator has not been received, the module222waits for a direction symbol size change request.

Responsive to receiving a directional symbol size change request, the symbol size adjustment module222selects610the next symbol size with respect to the current symbol size in the up or down size direction indicated in the request, adjusts612the symbol size for text symbol content on the display using the selected symbol size and set614the selected symbol size to the current symbol size.

FIG. 7is a flow diagram of a method for adjusting text symbol display size to a selected symbol size using animation in accordance with another embodiment of the present invention. For illustrative purposes only and not to be limiting thereof, the method embodiment500ofFIG. 5is discussed in the context of the system300ofFIG. 3. The symbol size adjustment module222determines702a number of symbol sizes from the current symbol size to the adjusted symbol size, orders703the symbol sizes in an indexed array from least to greatest, and determines704whether the adjusted symbol size is greater than the current symbol size. Responsive to the adjusted symbol size being greater than the current symbol size, the symbol size adjustment module222sets706gan indexing parameter K=adj Listed symbol size index and sets708ga loop range for a loop parameter I to cover the determined number of symbol sizes. In each loop iteration, symbol size adjustment module decrements710gthe parameter K, generates712ga display frame with symbol content at the symbol size indexed by K, and renders714gthe display frame with symbol content at the symbol size indexed by K in accordance with a selected animation function.

Responsive to the adjusted symbol size being less than the current symbol size, the symbol size adjustment module222sets706, an indexing parameter K=current symbol size index and sets7081a loop range for a loop parameter I to cover the determined number of symbol sizes. In each loop iteration, symbol size adjustment module increments7101the parameter K, generates7121a display frame with symbol content at the symbol size indexed by K, and renders7141the display frame with symbol content at the symbol size indexed by K in accordance with a selected animation function.

FIG. 8is a plot diagram illustrating some examples of animation functions that can be used in one or more embodiments of the present invention.FIG. 8represents symbol size in point sizes on the vertical axis and time in seconds on the horizontal axis. In this example, each of the animation functions802,804,806transitions from a 4 point size to a 12 point size in about 8 seconds. One example of an animation function is an S-Curve802in which the rate of change of the symbol size is slow at first, then has an acceleration of the rate of change which then tapers off near the target symbol size. Another example of an animation function is a linear function804which has a constant rate of change for the point size, 1 point size per second. The third example is an exponential function in which the rate of change of the point size increases exponentially.

Alternatively, some display units114such as that inFIG. 2Bcan use a limited set of symbol sizes (for example, unscalable bitmap fonts as opposed to scalable vector graphic representations) in which a distance tier (e.g., 4 to 5 feet) is assigned a symbol size associated with that distance, for example by using a mapping table218. Additionally, some display systems do not have fast enough rendering speeds for a smooth or non-jumpy and fast animation from for example an 8 point font size to a 20 point font size. Instead of animation techniques for displaying the change in symbol size, other transition effects can be used, for example fade in and fade out, in changing from one size to another can be used to accommodate displays with slower rendering speeds.