Obviousness

Obviousness Analysis of US Patent 7952645 under 35 U.S.C. § 103

This analysis identifies combinations of prior art references, explicitly mentioned in US patent 7952645, that would render the independent claims obvious to a person having ordinary skill in the art (POSITA). The motivation for combining these references is also discussed, often rooted in addressing known problems or achieving predictable results within the field of video processing for mobile terminals.

Prior Art References

The patent US7952645 itself acknowledges the following prior art:

• JP-A-2002-132225: Discloses "a multimedia computer system which converts an input RGB signal to a luminance signal and a color-difference signal, extracts a characteristic point in the luminance signal every frame, corrects the luminance signal and the color-difference signal, and conducts display".
• JP-A-2005-26814: Discloses "a side panel detection circuit which detects a side panel and conduct picture quality according to a result of the side panel detection and a result of video luminance level detection".

Obviousness Arguments for Independent Claims

Claim 1: Video Processing Apparatus with Context-Dependent Selector

Elements of Claim 1:
Claim 1 describes a video processing apparatus including:

1. An RGB-YUV converter.
2. A characteristic point detector that determines characteristics (minimum, average, maximum levels, and histogram) of the luminance signal, hue, and saturation.
3. A CPU that determines correction data based on these characteristics upon detecting an interrupt signal.
4. A modulator that corrects the luminance signal, hue, and saturation based on the correction data.
5. An HS-color-difference converter and a YUV-RGB converter.
6. A selector for choosing between the original or corrected video signal based on battery residual quantity, open/close state of the mobile terminal, or content type.

Combination of Prior Art:
A person of ordinary skill in the art would find Claim 1 obvious in view of JP-A-2002-132225 in combination with general knowledge of power management and user interface design in mobile terminals.

Rationale for Obviousness:
JP-A-2002-132225 clearly teaches the core video processing steps: converting RGB to YUV signals, extracting characteristic points from the luminance signal (implying the ability to analyze and derive correction data), correcting luminance and color-difference signals, and displaying the result. While JP-A-2002-132225 specifically mentions luminance characteristic points, a POSITA would find it obvious to extend the characteristic detection to include hue (H) and saturation (S) because these are directly derivable from the color-difference signals (R-Y and B-Y) that are already being processed. The motivation for this extension would be to achieve more comprehensive and aesthetically pleasing picture quality enhancement, addressing aspects of color perception in addition to brightness.

The inclusion of a selector (158) in a mobile terminal (as stated in the patent's description that the invention can be applied to portable telephones) to switch between the original and enhanced video signals based on factors like battery residual quantity, device open/close state, or content type, would be a well-known engineering design choice for power management and user experience optimization in portable electronic devices. For example, the patent itself mentions selecting the through signal in a waiting state to reduce power consumption. A POSITA would be motivated to combine the video enhancement techniques of JP-A-2002-132225 with such a selector to conserve battery life in a mobile device or to provide an optimized display experience based on usage context, leading to a predictable improvement in convenience for a battery-operated apparatus.

Claim 9: Mobile Terminal with Ambient Light Correction

Elements of Claim 9:
Claim 9 describes a mobile terminal incorporating the video processing apparatus of Claim 1, further including:

1. A photo sensor that detects ambient illuminance.
2. A CPU that determines additional correction data based on the detected ambient illuminance.
3. An RGB gain adjuster that applies the additional correction data to the video signal.

Combination of Prior Art:
Claim 9 would be obvious in view of the combination of JP-A-2002-132225 (as a basis for the video processing apparatus from Claim 1) and general knowledge in the art regarding ambient light sensors in displays, particularly in mobile devices.

Rationale for Obviousness:
Given a mobile terminal with video processing capabilities for enhancing picture quality (made obvious by JP-A-2002-132225 and common mobile device practices as discussed for Claim 1), a POSITA would recognize the problem of diminished display visibility in varying ambient light conditions, especially bright outdoor environments (as the patent notes, "In a bright environment such as outdoors in a clear day... the gradation on the low luminance side, i.e., the black side of the displayed image becomes hard to discriminate"). The use of photo sensors to detect ambient light and automatically adjust display parameters (like brightness or contrast) to improve readability and user comfort is a well-established technique in display technology. Integrating a photo sensor (21, as shown in FIG. 19 of the patent) into the mobile terminal and having the CPU (7) use its output to generate additional correction data (e.g., to emphasize black side gradations, as illustrated in FIGS. 23B/D) to be applied by an RGB gain adjuster (1510) would be a logical and predictable step for a POSITA. The motivation would be to address the known challenge of outdoor visibility in mobile displays, resulting in an image that is easier to view in bright surroundings.

Claim 10: Mobile Terminal with RGB Ambient Color Correction

Elements of Claim 10:
Claim 10 specifies the mobile terminal of Claim 9, where:

1. The photo sensor includes independent RGB detection elements.
2. The CPU calculates ratios among the RGB output colors of the photo sensor.
3. The RGB gain adjuster lowers the correction value for the color component that is much in quantity in the ambient light.

Combination of Prior Art:
Claim 10 would be obvious in view of the combination of Claim 9 (which includes ambient illuminance correction) and general knowledge in the art regarding advanced ambient light sensing for color temperature compensation.

Rationale for Obviousness:
Building upon the use of ambient illuminance for correction (as in Claim 9), a POSITA would further understand that the color temperature of ambient light also significantly influences perceived display quality. The patent highlights this problem, stating, "if the color of sunlight is reddish as in the evening sun, there is a problem that the color of the display image is made reddish under the influence of the sunlight". Employing a photo sensor with separate RGB detection elements to measure not just intensity but also the color components of ambient light is a known technique used in various fields, such as camera white balance or adaptive display technologies, to achieve more accurate color reproduction. A POSITA would be motivated to combine the ambient illuminance correction of Claim 9 with a more sophisticated ambient color temperature compensation to maintain color fidelity under diverse lighting conditions. Calculating ratios of the RGB components from such a sensor and intelligently adjusting the display's RGB gain to counteract the dominant ambient color (e.g., decreasing the R correction if ambient light has a strong red component) is a predictable and logical extension for improving overall display quality and user experience.

Claim 11: Mobile Terminal with Pattern Portion Detection and Correction Suppression

Elements of Claim 11:
Claim 11 describes a mobile terminal including a video processing apparatus where:

1. A detector detects whether "pattern portions" (e.g., wallpaper portions or patterned areas) are contained in the video signal.
2. If pattern portions are detected, the corrector (modulator) is controlled so as not to correct the video signal or to weaken the correction.

Combination of Prior Art:
Claim 11 would be obvious in view of JP-A-2002-132225 (for the general video processing) in combination with JP-A-2005-26814.

Rationale for Obviousness:
JP-A-2005-26814 explicitly discloses "a side panel detection circuit which detects a side panel and conduct picture quality according to a result of the side panel detection and a result of video luminance level detection". "Side panels" are functionally equivalent to "pattern portions" or "wallpaper portions" as described in US7952645, often inserted to fill empty display areas when content has a different aspect ratio. The patent identifies a clear problem: "If such a video signal is subjected to picture quality correction, then luminance and colors of the wallpaper portions are changed according to the contents of the video signal and consequently there is a risk that the image becomes rather hard to watch and the convenience in user's use becomes worse".

A POSITA, aware of the video enhancement techniques of JP-A-2002-132225 (or Claim 1's general video processing) and the side panel detection capability of JP-A-2005-26814, would be motivated to combine these teachings to prevent undesirable visual artifacts. The motivation would be to address the specific problem of static pattern portions (like side panels) flickering or changing luminance/color when global picture quality correction is applied, which degrades the viewing experience. JP-A-2005-26814 already suggests adapting "picture quality according to a result of the side panel detection". Therefore, controlling the corrector (modulator 152 in US7952645, as shown in FIG. 27) to stop or weaken correction for these detected pattern portions (as implemented by pattern portion detector 1511) would be a direct and predictable solution to maintain the stability and visual comfort of these static background elements.

Claim 12: Mobile Terminal with No-Picture Area Detection and Exclusion from Characteristic Detection

Elements of Claim 12:
Claim 12 describes a mobile terminal including a video processing apparatus where:

1. A detector detects whether "no-picture area portions" (e.g., single color black bars) are contained in the video signal.
2. If no-picture area portions are detected, the area where characteristic data is detected is controlled to exclude the no-picture areas.

Combination of Prior Art:
Claim 12 would be obvious in view of JP-A-2002-132225 (for the general video processing including characteristic detection) in combination with JP-A-2005-26814 (for area detection capabilities) and the problem identified in US7952645.

Rationale for Obviousness:
The patent explicitly states the problem addressed by this claim: "if black no-picture areas are added to the left and right sides of the contents having the aspect ratio of 4:3, luminance and color information of the black no-picture areas are confused. This results in a problem that average values of luminance and color of the 4:3 contents themselves cannot be calculated accurately".

Building on a video processing system that performs characteristic point detection for correction (as taught by JP-A-2002-132225, which extracts "a characteristic point in the luminance signal every frame"), and having knowledge of area detection (such as "side panel detection" from JP-A-2005-26814), a POSITA would be motivated to refine the characteristic detection process. The motivation is to ensure that the calculated luminance and color characteristics (e.g., histograms, average values) accurately represent the actual content of the video signal, rather than being skewed by static, non-informative "no-picture areas" like black bars. Detecting these single-color no-picture areas (similar to how JP-A-2005-26814 detects side panels) and then logically excluding them from the characteristic point detection area (as implemented by the characteristic point detection area controller 1512, shown in FIG. 37 and FIG. 38) is a straightforward and predictable engineering solution. This approach directly addresses the problem of obtaining accurate characteristic data for the main content, leading to more appropriate and effective picture quality corrections.