Flexible Glass Product 3 Years away

ZDNet is reporting that flexible glass products are still 3 years away. Flexible glass been offered for sale before. It was part of my product line in the mid 1990's and was already an old product then. The difference between Willow and Corning's previous flexible glass is that Willow is made with the same process used to make LCD substrates and has much better surface quality. There are two reasons for using a flexible glass substrate. One is cost reduction. (1) Roll-to-Roll processes are inherently lower cost than unitized production. However, roll-to-roll manufacturing is orders of magnitude harder to develop. This is especially true when manufacturing steps require specialized atmospheres. Added to this will be increased fab contamination from higher glass breakage with a spooled product; the bending puts the outer surface under some stress. As with all glass products, the edges are particularly susceptible to breakage but with a spool of glass, the breakage has much more glass that it can either propagate through and contaminate with micro-particles.

If, instead of cost reduction, the objective is (2) to merely make a flexible product, the spooled glass can be cut into sheets and handled like an ordinary substrate, only thinner. Shipping spools rather than individual sheets will result in some level of cost reduction but this may be off-set by higher breakage in glass and display manufacturing as well as transport breakage.

(2A)Also consider if the display will actually be flexible in use rather than just curved. If the objective is to make a curved display, rather than being flexible, it might be more beneficial to have a glass that can be reformed (sagged) at reasonable temperatures that will not spoil the TFT photolithography. Or, as with curved samuria sords (made from a straight piece of metal) it may be possible to heat treat or ion stuff the glass to develop a naturally cylindrical shape. The thinness of Willow will help with this.

The ZD Net article speculates that the product for flexible glass will be the iWatch. I expect this product may have a curved display that is not flexible, at least if it is an LCD rather than an OLED. I also would not assume that the first product of this type to come from Apple. Samsung had a standing request for Fusion drawn .1 mm glass (what is now called Willow) since flexible glass was first offered. They are also one of the leaders in OLED. They have been thinking about this for a good 20 years.

Barry Blundell's "3D Displays and Spatial Interaction"

Exploring the Science, Art, Evolution and Use of 3D Technologies

“3D Displays and Spatial Interaction, Vol I” has now been made available for free download from Barry's website – www.barrygblundell.com The book can be downloaded in two parts, the first PDF file contains the Front Matter plus Chapters 1 through to 4, and the second file contains Chapters 5 through to 9, the Appendix, and an extensive reference list (comprising just over 700 references).

Here are some excerpts from the Forward, "The author needs little introduction; he is a highly-regarded historian of ‘the technology of images’, with a deep knowledge fuelled by his own groundbreaking work in volumetric 3-D display. I have learned a great deal in the pages of Barry’s writings since I entered the field of 3-D display in 1988.

This book is exciting for two reasons. First, you’ll learn - in a very clear, completely illustrated manner – about perception, interaction, and image display. For example, in perception, you’ll encounter the architecture of the eye, a deep catalogue of depth cues, and the visual cortex. You’ll learn about haptics and interaction, including the fundamental Fitts’ Law of visual and physical target acquisition. The book is rounded out (so to speak) with Barry’s excellent teachings on a complete variety of three-dimensional displays, spanning stereoscopic, lenticular, parallax barrier, and volumetric systems.

Second, I enjoy his writing because he magically expresses treasure-troves of deep historical and scientific knowledge underlying a variety of topics. Ever wonder not about who really invented the stereoscope, but what they argued over? What’s a horopter or how do you compute 3-D imagery? Never mind ‘what’s a volumetric display’, what might its embedded electronics look like?

I hope you’ll agree that a book of this sort has really been a long time coming. When I got a sneak preview, I certainly enjoyed page after page of history and science that was new to me, even after working in the display industry for 20 years.

Gregg Favalora
August 2010
Former CTO, Actuality Systems, Inc.
Principal, Optics for Hire.
Arlington, Mass.,USA"

An Apple Branded TV Set v. the iWatch

A former senior executive at Apple recently said that an iWatch is a lot more likely from Apple than the much rumored Apple branded TV set. The reason he gave was that a watch is a much more personal item than a TV and more fitting with Apple’s previous initiatives. I would agree but for different reasons. As I have noted elsewhere that while 4K TV will have limited utility in consumer TVs, it will be a great boon to digital signage as the intended range of viewing distances for signage includes distances where 4K resolution really does matter. Further, 4K may be one of the first of a continuing stream of innovations to find a home in digital signage first before migrating to the general consumer TV market.

Apple does what it does by adapting new technology and pioneering new usage models. Absent participation in the digital signage market, Apple might not be able to do this on an ongoing basis in TV. Apple’s failure to include NFC in the latest rev of the iPhone may be due, in part, to wanting to avoid connecting smartphone innovation to the digital signage market. With 4K, the linkage between TV and digital signage innovation is here now and likely to grow.

Glass and the Russian Meteor

.... the Russian meteor stole the show Friday, fireballing across the Ural Mountains in spectacular fashion and exploding into fragments, creating a powerful shock wave that blew out windows, collapsed roofs and injured 1,200 people, mostly from broken glass.

A thing to consider about glass is that because of it partly random, partly ordered structured it is not necessarily electrically balanced on a atom to atom scale as would be the case with a fully crystallized material. This is especially true of a newly created surface. There are few things on earth quite as sharp as a freshly (freshly on the scale of microseconds) broken piece of glass. This is why, especially in situations such as an earthquake, it is a good idea to stay away from windows. The flying glass from a newly fractured window can fly right through skin and bone. Over time (seconds, minutes and for as long as a week) the electrically unbalanced nature of the new surface or of a scratch in the glass, begins to "heal" as the molecules at the newly created surface re-arrange their linkages to lower the surface energy. This healing also means that any glass particles created in a fracture or scribing operation can adhere themselves to another glass surface and become bonded there. As you would expect, every discontinuity in the glass surface has the potential to be a stress concentrator.

In general, glass strengthening processes such as thermal or chemical tempering are less effective on edges than they are on the body of a flat glass sheet. Part of this is geometry, part of this is how the edge was formed, and part is timing between the cutting and the strengthening operation. Though you would tend to think of glass as a static material, it does have its dynamic aspects. As I noted in a previous post, ion migration under the electron beam of a CRT eventually destroys the transparency of CRT glass to blue light. A bad cut, even for glass that is subsequently strengthened, even for glass that seems OK, will leave a weakened part.

The mobile device market periodically goes through periods of high display breakage. New suppliers or new staff have to attune themselves to the idea that their cutting process needs to be well engineered and maintained. Just because the glass is not shattering in their process or even in their customers does not mean that they are turning out quality for the end consumer.