1
00:00:00,480 --> 00:00:06,839
so it's 2:00 a.m. and you're laying alone on your coach watching reruns and

2
00:00:04,839 --> 00:00:11,440
suddenly your phone lights up with a message from a friend who needs a copy

3
00:00:09,200 --> 00:00:17,240
of a very important document that is sitting on your Cheeto dust covered

4
00:00:14,160 --> 00:00:19,160
coffee table for some reason so you go

5
00:00:17,240 --> 00:00:23,439
to take a picture of it with your phone but you realize your crappy built-in

6
00:00:21,080 --> 00:00:28,519
phone camera and the poor lighting from the dingy Bare Bulb hanging from the

7
00:00:25,640 --> 00:00:33,399
ceiling just aren't cutting it so decisively you dash to your PC and use

8
00:00:30,720 --> 00:00:37,800
your flatbed scanner and as you sit there listening to the whirling of the

9
00:00:35,399 --> 00:00:42,520
scanning mechanism and pondering how your life got to this point you find

10
00:00:40,320 --> 00:00:46,280
yourself asking how the heck do these things work

11
00:00:43,800 --> 00:00:51,039
anyways great question your typical scanner uses something called a charge

12
00:00:48,280 --> 00:00:56,239
coupled device or CCD to determine what's on the page the main idea here

13
00:00:53,600 --> 00:01:00,760
being that the CCD can convert light into an electrical charge which it then

14
00:00:58,079 --> 00:01:04,040
sends to your computer as Digital Data so when you start scanning a document

15
00:01:02,480 --> 00:01:08,560
that bright light that you see coming from inside typically from either a

16
00:01:05,880 --> 00:01:12,040
Xenon lamp or a cold cathode which as you may know is similar to what people

17
00:01:10,000 --> 00:01:16,560
used in PC case lighting a few years back hits the sheet of paper and was

18
00:01:14,080 --> 00:01:21,799
reflected back to a series of mirrors underneath the glass surface and then

19
00:01:18,479 --> 00:01:24,400
focused by a lens onto an array of CCD

20
00:01:21,799 --> 00:01:29,240
sensors since darker areas of the page containing things like text and clip art

21
00:01:26,920 --> 00:01:34,479
will reflect less light than the blank usually White areas the CCD array will

22
00:01:32,159 --> 00:01:38,479
see these differences which will show up as an accurate image of your document on

23
00:01:36,600 --> 00:01:42,840
your computer screen if you've ever had a scan of something bulky and had to

24
00:01:40,720 --> 00:01:47,200
leave the lid open a little bit you'll have noticed the scan is black in areas

25
00:01:45,240 --> 00:01:51,759
that aren't covered by anything this is because nothing's there to reflect the

26
00:01:49,119 --> 00:01:56,399
light though modern software is often smart enough to crop these areas out for

27
00:01:54,119 --> 00:02:01,039
you CCD arrays are also what determine a scanner's true resolution the more

28
00:01:58,759 --> 00:02:05,479
sensors in the array the more points of light it can capture and the more pixels

29
00:02:03,320 --> 00:02:09,200
it can send to your computer if you're in the market for a scanner make sure to

30
00:02:07,240 --> 00:02:14,400
check that the resolution on the spec sheet is the hardware resolution that

31
00:02:12,200 --> 00:02:18,640
reflects the true capabilities of the CCD array not some fake number achieved

32
00:02:17,000 --> 00:02:24,000
through software trickery like interpolation that uses average values

33
00:02:20,959 --> 00:02:26,200
of nearby pixels to approximate a higher

34
00:02:24,000 --> 00:02:31,000
pixel count image but what about color scanning this uses additional lenses and

35
00:02:28,920 --> 00:02:35,920
built-in color filters to separate the scan into red blue and green versions

36
00:02:34,120 --> 00:02:40,239
which are then processed to determine what the actual colors of your original

37
00:02:37,879 --> 00:02:45,200
document are although this is usually done with just one pass of the scanner

38
00:02:43,040 --> 00:02:50,360
some older models lack these additional lenses and so need multiple passes to

39
00:02:48,120 --> 00:02:56,840
complete a color scan which is why they were much slower in color mode but not

40
00:02:54,680 --> 00:03:01,680
every consumer level scanner works this way there are also flatbeds that use

41
00:02:59,040 --> 00:03:07,280
something called a contact image sensor or CIS instead of these ccds These are

42
00:03:05,360 --> 00:03:11,760
simpler in construction use an array of LEDs to shine light on the document so

43
00:03:09,640 --> 00:03:17,959
an image sensor can essentially take a snapshot of it like you were trying to

44
00:03:13,840 --> 00:03:20,360
do on the table with your cell phone but

45
00:03:17,959 --> 00:03:25,360
better although the scans from the CIS are typically lower quality than CCD

46
00:03:22,840 --> 00:03:29,000
scanners CIS is a cheaper more lightweight and more efficient

47
00:03:26,760 --> 00:03:33,840
technology so you'll find it in a lot of small port scanners that can be powered

48
00:03:31,480 --> 00:03:38,879
solely from a USB port instead of requiring a wall outlet of course there

49
00:03:36,599 --> 00:03:43,519
are other types of scanners out there such as expensive drum scanners with

50
00:03:41,599 --> 00:03:48,040
high dynamic range for professional applications as well as 3D scanners

51
00:03:46,080 --> 00:03:52,760
which you can learn more about right up here but hopefully this episode has

52
00:03:50,159 --> 00:03:56,959
given you a little insight into how your scanner at home works and let us know

53
00:03:55,120 --> 00:04:01,280
down in the comments down below if you'd like to see a future episode on what

54
00:03:59,079 --> 00:04:04,680
scanner to bu are you racing against the clock as a freelancer challenging yes

55
00:04:03,560 --> 00:04:09,519
but with the growth of the internet there's never been more opportunities

56
00:04:06,840 --> 00:04:13,680
for the self-employed to meet this need check out freshbooks Cloud accounting

57
00:04:11,360 --> 00:04:18,160
software it's a simple and easy way to be more productive organized and to more

58
00:04:16,040 --> 00:04:22,800
importantly get paid quickly you can create and send professionall look

59
00:04:19,680 --> 00:04:24,400
invoices in less than 30 seconds set up

60
00:04:22,800 --> 00:04:28,639
online payments with just a couple of clicks and get paid up to 4 days faster

61
00:04:27,000 --> 00:04:33,000
there's also my favorite feature you can see when a client has seen your invoice

62
00:04:30,759 --> 00:04:36,800
and put an end to the guessing games fresh books is offering a 30-day

63
00:04:34,600 --> 00:04:41,160
unrestricted free trial to our viewers to claim it go to freshbooks.com tewi

64
00:04:39,720 --> 00:04:44,199
and enter techwiki in the how did you hear about a section all right guys if

65
00:04:42,919 --> 00:04:48,199
you like this video like if you dislike to dislike it comment down below for

66
00:04:46,000 --> 00:04:52,759
other stuff that we should cover on this channel um follow this Channel with the

67
00:04:50,720 --> 00:04:55,520
Subscribe button hit the little bell there that lets you know every single

68
00:04:53,919 --> 00:04:59,039
time we get a new video also check out Channel Super Fun they're probably doing

69
00:04:57,560 --> 00:05:04,199
something hilarious over there they usually are and I'm going to roll out

70
00:05:00,759 --> 00:05:04,199
like a drum scanner