Wednesday, June 18, 2008

The HMD and the Washing Machine

Should see-through head-mounted displays be also used for completely immersive (non see-through) applications? Technically, it's certainly possible. Just put a dark cover on the front glass, and you have something similar to being completely immersive. However, having the extra weight, the not-quite-as-bright image and a bulkier product is certainly a downside for dual-use HMDs.

This reminds me of the washing machine / dryer combination. What a great idea on paper - no need to move laundry from one to the other. In practice, there are so many drawbacks to this combined approach that most everyone still has separate washers and dryers.

Not to showcase my age too much, but as a teenager I owned an Apple II computer. Not an Apple IIc. Not an Apple IIe. A real Apple II (serial number had 4 digits) and at that time, it would connect to our standard TV through a small conversion box. But, even though it made sense at the time, computers migrated very quickly to separating the TV from the computer monitor. Same concept, different time.

So... I still think see-through HMDs and fully-immersive HMDs should be kept separate for now.

Thursday, June 12, 2008

The Mind-Reading Virtual Binoculars

Northrop Grumman Corporation (NYSE:NOC) announced that it was awarded a contract to develop electronic binoculars that use brain activity to detect threats. The press release is here. My company is proud to partner with Northrop on this project.

The project seeks to present a panoramic day/night optical system to a user and monitor brain waves - yes, brain waves - to detect targets of interest. A panoramic view and high-resolution image was deemed very important for this project, which is why Sensics panoramic displays were chosen.

However, the drive to present users with diverse visual stimuli and measure brain activity is certainly not unique to the defense markets. We are working with several academic institutions to achieve much of the same goals within a research context.

Presenting users with narrow field of view displays could be considered not to put the human brain to full use as a super-fast object/pattern recognition computer. This is especially true given that difference parts of the visual field are used for different purposes: central vision is used for reading and perception of fine detail. Peripheral vision is used in humans and also in animals for threat detection, sensing movement and presence of peripheral objects. Try walking around with toilet paper rolls on your eyes (see this demo on the Washington Post) and you'll understand how critical peripheral vision is.

Monday, June 2, 2008

See-through HMDs have lots of ground to cover

See-through HMDs (sometimes referred to as 'personal displays') are sometimes portrayed as combining eyeglasses with a video ipod. In a perfect world, they look like cool fashion accessories, are so light that you can wear them anytime, yet overlay what you see through them with computer-generated images. Perhaps it's a movie that you can watch on a plane. Perhaps it's driving directions or text messages from your friends.

However, to get there, many problems remain to be solved:
- Brightness: can these devices be used in a sunny day?
- Weight: can you really walk around with them all day?
- Power consumption: how long does the battery last and where is the battery placed? If the battery is part of the HMD, it adds weight. If it's on a belt-clip, it adds inconvenience and perhaps a cable.
- User interface: how can you control what information is displayed, or when it is shown.
- Dual use: if the goal is to watch a movie, it's often better to block out external imagery. But how? Do you add a cover to the front? Do you make the glass part so dark that it's effectively like sunglasses?
- Placement of information: if the information is placed in the central vision, it might intefere with reading tasks. If it's placed in the peripheral vision, it is difficult to read. If it's both, you need a very wide display element.
- Stereo vision? At some level, a monocular display (one eye) might be sufficient for textual information. However, if you're looking to augment a scene, the feeling of stereo may be very important. Stereo, however, nearly doubles the weight, cost, power consumption and cabling requirements of the display electronics.
- Sound - can you or should you integrate the display with an earpiece
- Cost, for obvious reasons

I'm curious to see what Apple (who recently published some patents on this) and Sony (recently showing a cool display at SID 2008) have up their sleeves for this product category.