HDMI Video Input Device with Continuous Authentication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional video receiver apparatuses with multiple HDMI interfaces face long 'display waiting times' when switching between ports due to the need for repeated HDCP authentication, which increases implementation cost and power consumption.
Innovation Solution
A video input device with multiple reception interface sections, each equipped with a decryption circuit that includes a pseudo-signal generation circuit, allowing for continuous authentication using a pseudo-video signal when a port is not selected, thereby eliminating the need for re-authentication when switching between ports.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the hot plug detect of an unselected HDMI port is kept inactive to reduce device complexity, then the HDCP authentication process can be performed only for a selected HDMI port, but the display waiting time increases when HDMI ports are changed
Solution Approach 1:
The patent applies preliminary action by performing HDCP authentication in advance for all HDMI ports before port switching occurs. The authentication result is stored and reused when switching between ports, eliminating the need to re-authenticate during port changes. This resolves the contradiction by reducing display waiting time without requiring multiple authentication circuits.
2Loss of time
If multiple authentication ICs are provided for multiple HDMI ports to enable simultaneous authentication, then the display waiting time is reduced, but the implementation cost and device complexity increase
Solution Approach 1:
The patent applies universality by designing a single HDCP authentication circuit that can service multiple HDMI ports sequentially. The authentication result obtained through this single circuit is stored and reused across port switches, making the authentication function universal rather than requiring dedicated authentication ICs for each port. This resolves the contradiction by maintaining low device complexity while achieving fast port switching.
3Device complexity
If a single HDCP authentication circuit is used for multiple HDMI ports, then the device complexity is reduced, but the authentication process must be restarted when ports are changed, increasing display waiting time
Solution Approach 1:
The patent applies preliminary action by pre-performing HDCP authentication for all HDMI ports before switching occurs. The authentication results are stored in memory and retrieved during port switching, eliminating the need to restart authentication. This resolves the contradiction by enabling fast port switching with a single authentication circuit.
Solution Approach 2:
The patent applies continuity of useful action by maintaining authentication results in storage memory across port switches. Instead of discontinuing authentication when ports change, the system continuously utilizes stored authentication results, allowing seamless port switching without restarting the authentication process. This resolves the contradiction by maintaining high productivity with simple circuitry.
Data Source
AI summary
An input processing circuit decodes a digital video signal selected by an input signal selector. Decryption circuits each decrypt the encryption of a video signal output from the input processing circuit, and generate an authentication key of the encryption. A video signal selector selects and outputs one of the video signals output from the decryption circuits, to a monitor. The decryption circuits each include a pseudo-signal generation circuit which extracts information from the video signal, and based on the extracted information, generates a pseudo-video signal.