One of the features the iPhone lacks is the ability to display status indicators when the phone is in sleep mode. If you’re out and about and just want to know how much battery juice you have left, you have to press the Home button, which lights up the whole display (which drains the battery further), and then check the status icon for the battery.

This implementation suffers from several obvious problems. For one thing, it requires the press of a button every time you want to know some little detail like the battery status, the signal strength, or the time. Secondly, the glaring bright display can be jolting in the dark confines of someplace place like a movie theater, where viewers may grow annoyed at the disturbance.

In a recent patent filing by Apple, the company details how status indication could be achieved on an iPhone without having to keep the display powered on the whole time or necessitating the press of a button.

The patent describes a method of placing two light sources behind the display, one stacked on top of the other. The light source immediately below the display would be the bright, primary one and would itself be placed over a low-powered source that emits very faint light. Apparently, the secondary light source could then be made to pass light through several transparent or semi-transparent areas on the main lighting source, thus emerging as faintly lit, distinct status icons on the screen, even when the phone is in sleep mode. The secondary light source could then be used to create a blinking effect or something resembling the pulsing behaviour of the sleep indicator on Mac computers.

We’ll keep an eye on this and see if it materializes. It’s something that should have been present on the phone to begin with, really.