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many of the laptops we use today have an
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lcd display this is a liquid crystal
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display where there are a series of
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liquid crystals associated with color
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filters and there is a backlight or
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light source behind all of that that
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shines through to give us the image
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that's on our screen
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from a laptop perspective the advantages
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of an lcd display is that they are
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lightweight and use very little power
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and they're relatively inexpensive to
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make keeping the cost of the laptop down
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there are some disadvantages with lcd
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displays one is that this light source
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in the back has to shine through to
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provide the color which means getting a
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true black can be quite difficult on an
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lcd display we might also have different
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kinds of backlights on our displays the
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light source may be fluorescent it may
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be led or maybe some other type of light
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if this backlight was to fail you could
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see that it's part of the display itself
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making it relatively difficult to be
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able to repair or replace
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there are three different technologies
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of liquid crystal displays that you need
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to be aware of one is the tn lcd this is
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the twisted pneumatic lcd which gives us
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very good response times if you're a
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gamer or you're using some application
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that has fast moving graphics this may
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be the display type for you
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unfortunately these displays often have
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very bad viewing angles which means once
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you get off to the side of the display
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you'll notice there's an inversion of
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the color if you want the best possible
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view of a tn lcd you need to be looking
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directly at the display if you're
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looking for the best possible color
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representation on an lcd display you'll
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want to use an ips lcd the ips stands
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for in-plane switching this gives you
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very good color representation which is
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great if you're using graphics or doing
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some type of desktop publishing but
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these are slightly more expensive than a
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tn so that extra color representation
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comes at a bit of a cost
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if you like something that's in the
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middle between tn and ips you may want a
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vertical alignment lcd or a va display
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this has good color representation but
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you'll find the response times are a bit
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slower than a twisted pneumatic lcd
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if you have a newer device you may be
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using an oled display the oled stands
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for organic light emitting diode and it
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doesn't have a backlight instead this
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organic material emits light when you
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provide it with a current because
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there's no backlight no liquid crystals
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these are very thin displays and there's
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no glass that you would need on the
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front of the display to protect it the
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real key is that organic material that's
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able to create its own light when you
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provide it with power and that's what
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allows these displays to be very light
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and very thin you'll find them on
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tablets phones and smart devices not
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only because they provide such great
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color representation but because they're
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so light and so easy to carry
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one aspect of our laptop displays that
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we don't often think about is how
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they're used on wireless networks when
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you open the laptop your display is the
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highest component in that system so it's
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a perfect place to run your wireless
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antennas if you're using 802.11
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bluetooth or some other type of wireless
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networking then you probably have an
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antenna that runs to the top of your
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laptop display this creates some
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challenges when you are replacing the
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display because you not only have to
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remember to connect all of your video
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components you have to remember to
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connect all of these antenna wires as
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well
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here's a picture of a display this one
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does look a bit damaged you can see the
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primary connection that we use for the
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video signal but coming out of the other
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side of the display is a white and a
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black wire that's used for 802.11.
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you need to take care when replacing
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this display that you're following the
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same path that the previous wires took
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so that you could connect all of those
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wireless antennas to the appropriate
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components on the system board
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this is what it looks like when
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everything is in place you can see some
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antenna wires coming out of the system
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board they're wrapping around the system
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and these appear to wrap all the way
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into the top of this particular laptop
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if we look closely we can see wires that
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are used for the 802.11 network there
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are some additional wires also at the
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top of this display these are the wires
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that are used to bring the signal from
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the audio and video associated with the
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webcam
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many laptops these days have webcams
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integrated into the laptop itself that's
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a small little hole at the top for the
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camera and a tiny little dot right next
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to it for the microphone this can
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obviously be used for video capture but
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it's also used for meetings and video
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conference calls this makes it easy when
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you need to be on a zoom call you can
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simply open your laptop display and the
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camera built into the display will be
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able to show you on the call here's a
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better shot from this laptop which
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clearly shows that this is the webcam
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that's integrated into the laptop
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display and you can see there are holes
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also for the microphone in the display
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as well
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we mentioned earlier that a liquid
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crystal display needs some type of light
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behind the system to shine through so
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that we're able to see the images on the
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screen if you're working with an older
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laptop this might be a fluorescent type
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of light specifically a ccfl or cold
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cathode fluorescent lamp these require a
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bit more power than the led lights that
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we tend to use today and you'll find the
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led backlights are also a bit thinner
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taking up a lot less space on your
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laptop computer if you're working with
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an older laptop or you need to replace
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the display on an older laptop you may
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find that the backlight that it's using
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is a ccfl backlight
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newer lcd displays might use led lights
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instead of using a fluorescent lamp
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these led lights may be around the edge
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of the display or they might be in a
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matrix such as the one that's seen here
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these have become so common that instead
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of people referring to this as an lcd
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they often refer to it as an led display
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what they really mean of course is an
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led backlit lcd
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if you were to pull the front off of a
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display that has led backlights you
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might see the matrix behind it looking
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like this these are strips of led lights
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and you can see each one of these led
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lights is in a very large matrix behind
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the display
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the display is smart enough to recognize
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what parts of the display should be
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lighter or darker and will adjust the
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lighting depending on what you're
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viewing on the screen
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if you're working on one of these older
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laptops with ccfl or these fluorescent
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backlights you may also find some
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additional components behind the screen
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these are inverters we use these
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inverters because the ccfl backlight
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requires ac power but your laptop is
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using dc power the inverters are
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responsible for taking that dc power
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converting it to ac so that we can power
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those fluorescent backlights one way to
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tell if your backlight has failed is to
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shine a flashlight directly at the
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screen if you're able to make out some
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of the information on the screen it's
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very possible that the problem is not
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with the display but with the backlight
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behind the display
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if this is a ccfl backlight you may just
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need to replace the inverters and you'd
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be able to restore the backlight on some
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systems you may have to replace the
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entire display you'll have to check with
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the documentation for your laptop to see
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what applies for your particular model
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if you're using a hybrid device like
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this one that has a keyboard and a
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tablet type display you may be able to
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use a very high resolution input with
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this stylus that stylus allows you to
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directly draw on the screen and whatever
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you're pushing on the screen is
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converted into digital signals in the
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display we're able to provide that
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conversion because inside of this
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display is a digitizer that converts
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that analog input onto the display into
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digital signals that the computer can
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use
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the digitizer in your device may only
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allow for stylus input or it might also
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provide input using a touch screen a
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touch screen digitizer takes input from
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our finger converts it into a digital
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form to be used by that system it's a
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very common way to get information into
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a laptop or a tablet and we can often
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use a keyboard a stylus or key presses
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all on the same system to perform this
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input function
