Dear Jim, You've always been a man of vision - if I may say that - and out there, even in these rather stark economic times, should be a new group of engineeers and scientists, and strong blind organizations, and certainly a strong base of Optacon users, to dedicate themselves to a project, just as you dedicated your life's work! Judy Adams ----- Original Message --------------- Subject: [optacon-l] Re: Optacon article from January 2009 Braille Forum From: Jim Bliss <jamescbliss@xxxxxxxxx> Date: Mon, 26 Jan 2009 08:43:24 -0800 To: optacon-l@xxxxxxxxxxxxx >Mary, >Thanks for sending the Optacon article. It inspired me to write the >following draft of new Optacon ideas. I would be interested in any feedback >from the Listserv. > >Jim Bliss > >*New Optacon Design Ideas* > >*by James C. Bliss* > >*1/26/09* > >* * > > The Optacon was designed in the late sixties at the dawn of >integrated circuits, silicon photocell arrays, and before microprocessors. The >design was based on extensive experiments with human subjects, blind and >sighted, that used computer simulation of various designs to determine the >most effective for reading text. > >The final design incorporated a novel array of tactile stimulators composed >of piezoelectric reeds, or bimorphs, a custom integrated array of silicon >photocells, and custom integrated circuits of shift register/bimorph >drivers. > > The custom integrated circuits and unique piezoelectric reeds, >together with the small market, made the Optacon a difficult product to >source parts and manufacture. However, for those that mastered its use, the >Optacon filled an essential need. Even though the Optacon has been out of >production for over fifteen years, there are still over 150 avid users >trying to maintain their Optacons and demanding a new Optacon. > > Now, almost 40 years after the original Optacon design, advances >in technology make possible a new Optacon design that could have greater >resolution, be easier to learn and use, and could have features that would >greatly extend the applications of use. > > To reach the widest possible market, it is important to keep the >simplicity of the original Optacon while enabling new capabilities and >applications. Below are my thoughts on design possibilities that could be >considered. Not all of these ideas may be worth developing, but considering >them to assign priorities could help the process toward a new Optacon. > > > >I. Resolution and Field of View > > The original Optacon was designed around an array of 24 rows and >6 columns of pixels that drove a corresponding array of 24 rows and 6 >columns of bimorph tactile stimulators. The 24 by 6 was based on tests >with human subjects that indicated this was the minimum number of pixels for >reading and tracking text at a practical speed. Actually, if you consider >24 pixels across a 0.1 inch letterspace, this is equivalent to only 240 >dots/inch compared to the 300 dots/inch typically considered to be the >minimum needed for OCR. Also, the Optacon's 24 pixels across a 0.1 inch >letterspace is equivalent to a visual resolution of only 20/40. > > In addition, reading with an Optacon requires the user to move >the hand held camera along a line of text. The limited field of view of the >Optacon camera requires this scan to be very precise; else the images of the >text are cut off. So reading would be easier and faster if the field of >view of a new design could be greater, thereby relaxing the precision needed >for line tracking. > > Thus, for ease of tracking and reading a wider range of text >fonts and text quality, more pixels would certainly be better, analogous to >the greatly enhanced picture quality resulting from the recent television >change from a 480 line interlaced scan to a 1080 progressive line scan. > > Fortunately, advances in technology make an improved resolution >and field of view possible at a reasonable cost. Therefore, I believe that >a goal of basing a new design on 36 vertical pixels to provide both improved >resolution and greater field of view should be considered. > > Unfortunately, the Optacon II, which was designed by Canon, had >only a 20 by 5 array. This reduction in resolution and field of view was >one of the reasons reading is more difficult with it. > > In the original Optacon design, the pixels were not square, but >rectangles that were twice as wide as they were high. This is because when >camera is moved along a horizontal line of text the letterspace is sampled >in the vertical direction, but an analog signal is obtained horizontally >across the letterspace. All of the image information can be obtained from >one column of pixels moved horizontally across the letterspace. However, >tests with human subjects clearly showed that reading accuracy increased as >more columns were added. > > Based on these considerations, I suggest that a new design have >12 columns across the same horizontal field of view as the original Optacon. >Thus, the newly designed Optacon's pixels would be square, with the vertical >and horizontal resolutions being the same. The 36 by 12 array would >increase the number of pixels to 432, compared to the 144 in the original >Optacon, perhaps justifying a name for the new model as "Optacon HD" for >"high definition". > > > > > >II. Tactile Array > > In the past 40 years, there have been some significant advances >in piezoelectric materials. Several years > >ago there was a study at Stanford University that indicated the bimorph >reeds in the Optacon tactile array could be half as long as in the original >design. This would allow incorporating the increased number of bimorphs in >approximately the same space as before. > > A complaint about the Optacon has been the noise that it makes. >This noise comes from the bimorphs, which are being driven by a 250Hz square >wave, a frequency of maximum tactile sensitivity. This provides a strong >tactile sensation. The bimorph reeds were designed to be at near resonance >at this frequency to consume a minimum amount of power from the battery. After >the Optacon design was finalized and production had begun, we discovered >this noise was greatly reduced if the bimorphs are driven with a 250Hz sine >wave instead of a square wave. This is because the human ear is much more >sensitive to the harmonics of a square wave than to the fundamental 250 Hz >frequency. However, we never had the opportunity to test whether there was >any detrimental effect on the tactile sensation when a sine wave drive is >used instead of a square wave. In a new design this should be tested and >the sine wave used if desirable. > > At Telesensory the assembly of the tactile array was labor >intensive requiring considerable skill. Modern manufacturing techniques >including robotics could help reduce this cost. > > > >III. Retina Module > > When the Optacon was designed, no suitable integrated solid >state arrays of photocells were available, so a custom design was developed >in the Stanford Laboratories. Finding and maintaining sources for this >custom part at the relatively low quantities needed made Optacon production >difficult and expensive. Now integrated solid state arrays of photocells >are widely used in digital cameras, web cams, cell phones, etc. Thus in a >new design, a standard off-the-shelf part should be used if at all possible. > > > >IV. Lens Modules > > The original Optacon lens is not a true zoom lens because only >the lens is moved to change the magnification. This meant that the image is >only in true focus at two points along the zoom range and out of focus at >the ends and middle of the zoom range. The amount of out of focus is >sufficiently small to not be a problem given the low resolution of the >original Optacon retina. Because of the increased resolution I'm suggesting >in a new design, a better zoom system will be required. Actually, one of >the Optacon prototypes built at SRI and Stanford did have a zoom system that >moved both the lens and the retina to keep the image in true focus. This >did not change the size of the camera and would not be a significant >increase in cost after tooling for production. > > Various lens modules, such as the typing attachment and CRT >screen module, were very important for the Optacon market because they >increased employment applications. While these particular accessory lens >modules are not as important today, others could be developed for producing >handwriting, reading LCD screens, viewing and taking pictures at a distance, >etc. > > In addition to image signals from the Optacon camera, an >independent signal indicating camera movement should be considered. While >sometimes this can be derived from the camera images, there may be >situations in which it may be desirable to have signals from the lens module >rollers. > > > >V. Electronics > > Since the original Optacon was designed before microprocessors, >the electronics did not include a microprocessor, however Optacon II did and >any future designs most certainly would. In addition, a new design could >include some image storage as well as a port for an external memory >stick. This >would enable camera scans to be stored for later retrieval and/or further >processing on a PC. > > OCR and synthetic speech capability could be built into the >Optacon electronics. These capabilities, together with the storage >capability, means that the new design would need to have file handling and >other software built-in. > > A very important control on an Optacon is the threshold, which >determines the photocell signal level between black and white. Especially >for poor quality print and for different colored print, how the threshold is >set can determine whether the text is readable or not. For precision >threshold setting, I think this part of the circuitry should be analog with >a high resolution potentiometer. Unfortunately, in Optacon II this control >was digital with too few bits for precision. > > In addition to threshold and tactile stimulator intensity, there >would need to be some additional controls, or buttons, similar to those on a >"point and shoot" digital camera, for deleting images from storage, cycling >through a menu, etc. > > > >VI. Ports > > A new design could have a port for the camera (possibly >wireless), a port for power (batteries could be charged in the Optacon or on >a separate charging station), a port for a memory stick, and a USB port for >sending camera images to a PC, for enabling the PC to write on the tactile >array, and for enabling new software to be installed in the Optacon. > > > >VII. Battery > > The Optacon II design was an improvement in battery convenience >over the original Optacon and a new Optacon design could improve things >further. A system with readily available batteries that the user could >easily replace and charge should be the goal. > > > >VIII. Packaging > > The Optacon II design was an improvement in packaging over the >original Optacon and a new Optacon design could improve things further. > > > >IX. PC Software for the Optacon > > By providing a new Optacon with a USB port where camera images >can be transferred to a PC and the PC can write tactile images on the >Optacon means that the basic simplicity of the Optacon can be maintained >while providing the possibility of adding many new features for expanding >Optacon use. Some examples are: > > > > A. Optacon Reading Lessons and Speed Building > > Optacon training was essential in producing so many people that >were successful in Optacon use. Teaching someone to use an Optacon >effectively was a labor intensive process. The most successful Optacon >training programs involved one teacher full time for every student for >several weeks. Since the seventies when these programs started, labor costs >have dramatically increased relative to the cost of technology. > > However, with the widespread availability and increased >capability of PCs, it is now feasible to develop software that could >automate at least part of the training process. The PC could write letters, >words, and text on the Optacon tactile screen, build speed by presenting >these at various rates, test student progress, and provide feedback through >synthetic speech. > > > >B. Speech and Braille Output > > By OCR processing the images from scans from the Optacon camera, >the PC could provide speech or Braille output. Several tactile stimulators >could be combined to simulate a Braille dot on the Optacon's tactile screen. >Speech and Braille files could be stored in the PC in addition to image >files. > > > >C. Optacon Screen Reader Software > > Optacon screen reader software could be developed in which >images from the PC screen were displayed on the Optacon tactile array. The >PC mouse could be used to move the field of view of the tactile image around >on the screen. This could be particularly useful in understanding screen >layout, viewing graphics on the screen, and in formatting documents. > > > >X. Conclusion > > I believe that developing and disseminating a new Optacon along >the lines described here would significantly enhance the educational and >vocational opportunities, as well a personal independence, of blind people >around the world. I've described a design that would preserve the basic >simplicity of the original Optacon, greatly improve the quality of the >tactile image, and make tracking along a line of text easier. By adding the >capabilities of memory storage and communication with a PC, new features >could be developed to make reading easier and faster through speech and >Braille, and that would expand Optacon applications. These design ideas >need to be evaluated by the blindness community. > > My guess is that the development of this basic Optacon alone >could cost several million dollars. (The PC software and other accessories >could be developed later by third parties.) However, the relatively small >market coupled with the cost of development and the difficulties of selling >to this market will discourage private companies from taking on such a >project. The situation is analogous to that with low incidence diseases >where biopharmaceutical companies don't develop treatments unless there is >some consideration such as "orphan drug status". > > The hope for bringing back a new Optacon might rest on obtaining >grant support for development and dissemination from private foundations or >government. For this to be viable would require strong support from the >blindness community and leadership from an organization with the capability >of accomplishing the task. > > > to view the list archives, go to: www.freelists.org/archives/optacon-l To unsubscribe at any time, just send a message to: optacon-l-request@xxxxxxxxxxxxx with the word "unsubscribe" (without the quotes) in the message subject. Tell your friends about the list. They can subscribe by sending a message to: optacon-l-request@xxxxxxxxxxxxx with the word "subscribe" (without the quotes) in the message subject.