Obviousness

Obviousness Analysis of US Patent 7577417 under 35 U.S.C. § 103

This analysis identifies combinations of prior art references that would render the claims of US Patent 7577417 obvious to a person having ordinary skill in the art (POSA) at the time of the invention (priority date: April 3, 2002). The primary goal of the invention, as stated in the patent, is "to attain both enhancement in processing speed and reduction in current consumption" in a mobile terminal. [cite: US7577417B2]

Independent Claim 1:

Claim 1 describes a mobile terminal capable of being changed from an open condition into a closed condition, comprising a processor and a clock controller. The clock controller adjusts the clock signal frequency as follows:

• A first frequency when the terminal is in the open condition.
• A second frequency (lower than the first) when the terminal is in the closed condition.
• A frequency higher than the second frequency for a specific processing, even if the terminal is in the closed condition.
• The frequency reverts to the second frequency after the specific processing is completed.

Identified Prior Art and Their Teachings:

The patent itself references the following prior art:

1. JP-A NO. 73237/1999 (Fujitsu Ltd.): This reference discloses "a hand-held terminal or mobile terminal, for switching the frequency of a clock signal delivered from the side of an application program". [cite: US7577417B2] This teaches dynamic clock frequency adjustment in mobile terminals based on the demands of application programs, implying higher frequencies for performance-intensive applications and lower frequencies for less demanding or idle states to save power.
2. JP-A No. 148475/2000 (Toyota Motor Corp.): This reference discloses "a computer for a mobile unit, capable of switching a clock frequency to a high-speed mode frequency higher than a normal frequency when conditions, such as power source voltage, ambient temperature, and so forth, are satisfied". [cite: US7577417B2] This teaches dynamic clock frequency adjustment in mobile units based on various system conditions, switching to a higher speed when warranted.
3. GB2297661A (Motorola Inc.): This reference describes a "Radio communication device with moveable housing element and touch screen". [cite: US7577417B2] This patent, published in 1996, teaches the concept of a foldable or clamshell-type portable radio communication device with first and second housing elements that are movably coupled.

Obviousness Argument for Claim 1:

A person having ordinary skill in the art (POSA) in mobile terminal design, at the time of the invention's priority date (April 3, 2002), would have possessed knowledge of:

• Mobile terminals with hinged or foldable structures, allowing for distinct "open" and "closed" physical conditions. [cite: GB2297661A]
• Processors and clock controllers in mobile devices capable of executing program processing and changing clock signal frequencies. [cite: JPH1173237A, JP2000148475A]
• The general principle of dynamic frequency scaling (DFS) to manage the trade-off between processing performance and power consumption in mobile devices. [cite: JPH1173237A, JP2000148475A] DFS could be triggered by application demand or various system conditions. [cite: JPH1173237A, JP2000148475A]

Motivation to Combine:

The constant challenge for mobile terminal designers is to extend battery life while maintaining an acceptable user experience. Given this objective, a POSA would have been motivated to combine the teachings of the aforementioned prior art references as follows:

1. Combining GB2297661A with JP-A No. 148475/2000 and/or JP-A NO. 73237/1999 for Open/Closed Condition Frequency Control:

   • A POSA familiar with foldable mobile terminals (as taught by GB2297661A) would recognize that the "closed condition" typically indicates reduced user interaction and often a standby mode, where the demand for high processing power is minimal. [cite: US7577417B2]
   • Therefore, it would be an obvious design choice to treat the "closed condition" as a "condition" (as per JP-A No. 148475/2000) or a state of low "application program" demand (as per JP-A NO. 73237/1999) that warrants reducing the clock frequency to conserve power. [cite: US7577417B2]
   • Conversely, the "open condition" would naturally be associated with active user engagement, necessitating a higher clock frequency (the first frequency) for optimal performance. This combination directly addresses the claim elements of setting a first frequency in the open condition and a second, lower frequency in the closed condition. [cite: US7577417B2]

2. Further Combining for Specific Processing in Closed Condition:

   • Even in a power-saving, closed state, a mobile terminal might still need to perform "specific processing" (e.g., handling incoming calls, displaying brief notifications on an external screen, or executing quick, user-initiated functions). [cite: US7577417B2] These "specific processing" tasks are analogous to the "application programs" in JP-A NO. 73237/1999 that might require higher frequencies, or "conditions" in JP-A No. 148475/2000 that trigger a high-speed mode.
   • A POSA would be motivated to temporarily increase the clock frequency (to a frequency higher than the second frequency) for such specific processing, even when the terminal is closed, to ensure adequate responsiveness and user experience. This is a logical application of known dynamic frequency scaling principles to prioritize performance when needed, regardless of the overall power-saving state.
   • Once the specific processing is complete, it would be equally obvious to revert the clock frequency to the lower, power-saving second frequency, to continue conserving battery life. This cyclical adjustment is a standard practice in power management for transient tasks.

The patent itself describes the rationale for these actions as beneficial for operability and current consumption, stating that in the closed condition, "the user does not look at a display screen of the cellular phone, and is often in no hurry to do processing. Accordingly, in the case of the closed condition, processing can be executed while reducing power consumption by changing the frequency of the clock signal to a lower frequency." [cite: US7577417B2] This reasoning further underscores the obviousness of applying known power-saving techniques to the distinct physical states of a foldable device.

Therefore, the combination of GB2297661A, JP-A NO. 73237/1999, and JP-A No. 148475/2000 would render Claim 1 of US Patent 7577417 obvious because a POSA would have been motivated to combine these teachings to optimize power consumption and processing speed in a foldable mobile terminal by applying known dynamic clock frequency scaling techniques based on the terminal's physical state and the demands of specific tasks.