[Blindmath] Tactile embosser Resolution

[George Bell]

Hi John,

Dare I suggest a better term might be to refer to, "Resolution" as distinct from DPI (Dots Per Inch)?

George.

-----Original Message-----
From: Blindmath [mailto:blindmath-bounces at nfbnet.org] On Behalf Of John Gardner via Blindmath
Sent: 18 December 2014 15:58
To: 'Ian Chris'; 'Blind Math list for those interested in mathematics'
Subject: Re: [Blindmath] Tactile embosser Resolution

Ian, this is just another example of how some manufacturers imply more than what actually occurs.

The new ViewPlus Embraille embosser has a resolution of 300 dpi in the sense of this 50 dpi number you quote.  But we do not say that.  At least not without some explanation. 300 dpi is not a measure of how many dots can be embossed in a one inch line - it is the accuracy with which a dot can be placed on the paper.  50 dpi is actually a pretty crude value if one wants to produce braille with official NLS spacings.

You could never emboss 50 dots in a one inch line.  Or rather, if you did emboss 50 dots per inch, you would just be embossing a big mess.  And it wouldn't help.  Anything more than 20 dpi is beyond the resolution of the static sensors in fingers.  Few people can distinguish 20 dpi line from a solid line when just placing a finger on it.  If you move that finger or use a fingernail, you can tell the difference, but it doesn't actually provide any more information. 

Hope this helps.

-----Original Message-----
From: Blindmath [mailto:blindmath-bounces at nfbnet.org] On Behalf Of Ian Chris via Blindmath
Sent: Wednesday, December 17, 2014 10:54 PM
To: Blind Math list for those interested in mathematics
Subject: [Blindmath] Tactile embosser Resolution

Dear List members,

I was studying the tactile outputs of a braille embosser, it says that the resolution (for tactile embossing)  is 50 DPI, which in printing terms shall mean that there are 50 dots in a length of 2.4 MM. In other words there are 50 projections in a straight line if embossed in an inch that is equal to 25.4 mm.This shall mean that the dot size is 0.5 MM in diameter.
All the above is just a theoretical assumption.

If i have to fit in 50 dots in a row 0.5 mm with no spacing in between my assumption is that the dot diameter read the projection diameter or the surface area is equal to 0.5 mm. Now if if have to distinctly feel each dot there has to be a minimum separation between the two. I am confused if i can get the resolution of 50 DPI in the embossing.


Experts may comment on the same as it is not leading to any understanding of the embossing possibilities for one of my samples. also this is not specific to a specific brand of embossers. The sample that i am working on is also one of its kind and has no significance whatsoever but this inability to understand is driving me crazy.

Regards,

Ian
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