Phone users would then see any obstacles looming up on them as they walked.
In patent designs, the familiar white background to an iMessage chat is replaced by video- with the text bubbles either opaque or semi-opaque.
The system would be activated through an in-app button and could be adapted for use in web browsers, or even iBooks, with text floating over the live background.
The system would require users to point the smartphone directly in front of them, as more orthodox phone-use would simply provide a megapixel view of the pavement.
But the patent said the development would prevent users "colliding with or stumbling over objects".
It was filed with the US Patent and Trademark Office in September 2012, but was unearthed this week by technology journalists in America.
The application, which credits Stephen Ward as the inventor, says: "The background within the text messaging session can continuously be a live and current video image of the view seen by the camera at any given moment.
"Consequently, the device's user is less likely to collide with or stumble over an object while participating in a text messaging session."
It is not clear if or when the device will be available to iPhone users, with Apple yet to confirm whether the system will be incorporated into its next iOS system.
Many patent applications fail to see the light of day.
The patent is illustrated by a line drawing demonstrating a bizarre iMessage exchange about a scary cow with a tree displayed on the background screen.
As a further message is sent, the tree is seen larger on the screen, alerting the user to the looming peril.
"Due to the visual nature of a text messaging session, such a user often will find it difficult to divide his attention between his device's display and his environmental surroundings," the application- titled transparent texting- adds.
"A user who is walking while participating in a text messaging session may inadvertently collide with or stumble over objects in his path because his attention was focused on his device's display instead of the path that he was traversing.
"Even if a user remains stationary while participating in a text messaging session, that user may expose himself to some amount of danger or potential embarrassment if he is so engaged in his device's display that he becomes oblivious to changes in his surrounding environment."
"Alternative embodiments of the invention can be applied to virtually any computer-executable application in which text is presented over a background," it adds.
The company's next software launch is set to be iOS 8- due in September - which will provide technological updates to iPhone and iPad devices.
- THE INDEPENDENT
