Xeroxing mirrors

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6 total messages Started by pauls Fri, 10 Apr 1992 15:26

#1074

Author: pauls
Date: Fri, 10 Apr 1992 15:26

6 lines
456 bytes

Can somebody explain this to me??

I tried to Xerox a flat mirror. The paper came out pitch black.

Well??

Re: Xeroxing mirrors

#1081

Author: Jon J Thaler
Date: Sat, 11 Apr 1992 21:21

13 lines
938 bytes

In article <8400009@trsvax>, pauls@trsvax.tandy.com says:

> Can somebody explain this to me??
> I tried to Xerox a flat mirror. The paper came out pitch black.
> Well??

I would suppose that a photocopier uses the diffuse reflection from
the document to be copied.  Paper does not have much specular
reflection (and that which it does have is not from the ink - try reading
a glossy magazine when the reflected light shines in your eyes).

Your mirror, having *ONLY* specular reflection, is as invisible to the
copier as the glass plate you put the paper on.

Re: Xeroxing mirrors

#1100

Author: Kenneth Sloan
Date: Mon, 13 Apr 1992 15:57

16 lines
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In article <8400009@trsvax> pauls@trsvax.tandy.com writes:
>
>Can somebody explain this to me??
>
>I tried to Xerox a flat mirror. The paper came out pitch black.
>
>Well??

What color did you expect it to be?


-- 
Kenneth Sloan                   Computer and Information Sciences
sloan@cis.uab.edu               University of Alabama at Birmingham
(205) 934-2213                  115A Campbell Hall, UAB Station 
(205) 934-5473 FAX              Birmingham, AL 35294-1170

Re: Xeroxing mirrors

#1105

Author: David J Bell
Date: Mon, 13 Apr 1992 16:36

33 lines
1324 bytes

>Can somebody explain this to me??
>
>I tried to Xerox a flat mirror. The paper came out pitch black.

>Well??

Makes sense...   If you think about the geometry of the
illumination and imaging systems in the copier, you'll
realize that the light source and imageing lens/drum
cannot be on the same path. The original is lighted from
the side(s), while the lens is carried along perpendicularly
to the paper's surface:

                 Original
            =======================
      Lamp   \*__ 
                     <==>  Lens

                      --
                     (__)  Photo-sensitive drum



What the imaging system would "see" would be a reflection of
its own reflected or emitted light, NOT the light from the
lamp. Those parts are carefully designed not to reflect any
significant amount of light onto the original or carrier plate.
If they did, a shiny original, or even worse, the glass carrier,
would always cast a reflection on the image...


Dave

Re: Xeroxing mirrors

#1204

Author: Blair P. Houghton
Date: Tue, 14 Apr 1992 21:32

9 lines
709 bytes

In article <8400009@trsvax> pauls@trsvax.tandy.com writes:
>I tried to Xerox a flat mirror. The paper came out pitch black.

What color is a mirror?

				--Blair
				  "Rabbi 1:  Is it best to answer a
				   question with a question?
				   Rabbi 2:  Is there a better way?"

Re: Xeroxing mirrors

#1266

Author: Daniel Connelly
Date: Fri, 17 Apr 1992 20:34

10 lines
697 bytes

In article <10407@inews.intel.com> bhoughto@hopi.intel.com (Blair P. Houghton) writes:
>In article <8400009@trsvax> pauls@trsvax.tandy.com writes:
>>I tried to Xerox a flat mirror. The paper came out pitch black.
>What color is a mirror?

White.


Dan
--

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