in the name of GOD in this slides we express about tfts and retina. and then express how people who is blinde can see with retina. this project have many picture about its topics and express them.

1. 1

2. 1. Thin film transistor 6
2. Manufacture 7
3. Applications 12
4. Amoled screen
14
5. Mobile Display 19
6. Artificial retina 24
7. Phototransistor
28
8. Retinal implantation
29
9. Wireless power supply
32
10.Artificial retina 34
11.Conclusion
36
12.References
39
2

3. In our research we want to express TFTs and its usages.
3

4. A thin-film transistor (TFT) is a special kind of field-effect transistor made by
depositing thin films of an active semiconductor layer as well as the dielectric
layer and metallic contacts over a supporting (but non-conducting) substrate. A
common substrate is glass, because the primary application of TFTs is in liquid-
crystal displays. This differs from the conventional transistor, where the
semiconductor material typically is the substrate, such as a silicon wafer.
4

5. TFTs can be made using a wide variety of semiconductor materials. A common
material is
silicon. The characteristics of a silicon-based TFT depend on the silicon's
crystalline state.
By using transparent semiconductors and transparent electrodes, such as
indium tin oxide (ITO), some TFT devices can be made completely transparent.
Such transparent TFTs (TTFTs) can be used for construction of video display
panels.
5

6. 6

7. As with all transistors, this latest design has three electrical contacts: a source,
a drain and a gate. And between the gate and the semiconductor material sits
an oxide layer. In terms of materials to fill out these components, the Canadian
researchers have used the intrinsically n-type semiconductor zinc oxide and
deposited it on a p-type silicon (p-Si) wafer.
7

8. An important advantage of the bottom-gate coplanar structure (B) is that the
gate dielectric layer and the source and drain contacts are prepared before the
organic semiconductor is deposited.
8

9. Identification of the proper TFT
structures
9

10. Over the years,full-color flat panel displays,represented by thin-film
taransistor(TFT) liquid crystal display(LCD),have enabled many new
applications,such as the digital camera, notebook PC and thin, flat-screen TV,
through intensive research activitis around the world.
10

11. 11

12. AMOLED (active-matrix organic light-emitting diode) screens also contain a
TFT layer.
The most beneficial aspect[neutrality is disputed] of TFT technology is its use of
a separate transistor for each pixel on the display. Because each transistor is
small, the amount of charge needed to control it is also small. This allows for
very fast re-drawing
of the display.
AMOLED screens
12

13. The best known application of thin-film transistors is in TFT LCDs, an
implementation of LCD technology. Transistors are embedded within the panel
itself, reducing crosstalk between pixels and improving image stability.
TFT panels are frequently used in digital radiography applications in general
radiography.
13

14. 14

15. 15

16. 16

17. TFT LCD It uses active matrix technology and places a transistor next to each
pixel enabling it to be turned on and off individually. This technology is favorite
among smartphone manufacturers because it gives satisfying image quality
and resolution and has a response time that is high enough. However,
charging such a display is a.demanding task, which results in poor
Mobile Display
17

18. An AM OLED display uses the TFT backplane just as a TFT LCD does, but it
has self-light emitting organic material instead of non-light emitting liquid crystal
material. Mobile devices are the main application for AM OLED displays.
18

19. Even in these past several years, display specifications for smartphones
have been drastically improved. For comparison.
Ppi:pixels per inch
[6]
19

20. Smartphone/mobile phones shipment forecast by display pixel density.
[6]
20

21. Industry value growth of TFT LCD and AM OLED displays, by application.
[6]
21

22. The Artificial retina made using Thin-Film transistor ,which can be fabricated
on transparent and flexible substrates.
A Thin-Film transistor (TFT) is s special kind of field-effect transistor made by
depositing thin film of the dielectric semiconductor layer.
Artificial retina
[2]
22

23. Artificial retinas have been ardently desired to recover the sight sense for sight-
handicapped people.
An artificial retina using thin-film transistors (TFTs),which can be fabricated on
transparent and flexible substrates.
[2]
23

24. 24

25. The artificial retina using TFTs is fabricated using the same fabrication
processes as conventional poly-Si TFTs and encapsulated using SiO2
in order to perform in corrosive enviroments.
25

26. The phototransistor is a device that is able to sense light levels and alter the
current flowing between emitter and collector according to the level of light it
receives.
Phototransistors and photodiodes can both be used for sensing light, but the
phototransistor is more sensitive in view of the gain provided by the transistor.
This makes phototransistors more suitable in a number of applications.
[1]
26

27. Three types of retinal implants are currently in clinical trials: epiretinal (on
the retina), subretinal (behind the retina), and suprachoroidal (between
the choroid and the sclera).
[7]
27

28. [2]
28

29. 29

30. The wireless power supply using inductive coupling is shown in below pic. The
right graph in below pic is a measured stability of the supply voltage.
[8]
30

31. 31

32. 32
These devices include micro-electrodes that are surgically placed inside or
near the eye along the optic nerve or into the brain. Micro-electrode stimulates
parts of the vision system that still perform in the person who lost their
sight.The electrical stimulation of the remaining neurons causes the individual
to see small spots of light called phosphenes. These phosphones are used in
bionic eye (s) for visual scene design. Therefore, vision from the artificial eye
is not a natural look; a collection of light spots and shapes that a person uses
to interpret his surroundings.
How do people see with artificial retina?
[9]

33. 33

34. 34
Phosphen is a phenomenon in which the experience of seeing light without
entering light into the eye occurs, such as observing the color when we close
our eyes.
Phosphones
[9]

35. 35
There are many ways to treat blindness, which is the first step towards the end
of absolute blindness, and this is for patients who are suffering from extreme
blindness who are blinded and lack of understanding of normal light.
The vision of the artificial eye is very basic and can be used for tasks such as
identifying the location of an object, identifying a person, or finding a way.
[9]

36. 36
Our country has a lot of scientific capabilities and today, in the field of
ophthalmology, we are witnessing the first artificial retinal retinal transplant in
the country.
Although this view is not very high, for the disease with this degree of ocular
problem, it is proud for us the doctors who initiate this scientific movement
[9]

37. 1) https://en.wikipedia.org/wiki/Photodiode
2) https:www.slideshare.net/venkataraja353/artificial-retina-using-thin-film-transistor-
technology
3)NPD Displaysearch, Quarterly Mobile Phone Shipment and Forecast Report, Q3 2014.
4) Japan Display Inc.
5) K. Noguchi, Y. Kida, K. Ishizaki and T. Takeuchi, “Novel In-Cell Capacitive Touch
Panel Technology in a Wide Viewing Angle IPS-Mode Display” presented at
EuroDisplay2011, S11.
6) IEEE Asian Solid-State Circuits Conference.mobile display technologies :past,
present & future.hiroyuki Oshima,Japan Display Inc.,tokyo,japan.
7)https://spectrum.ieee.org/nanoclast/semiconductors/devices/introducing-one-of-the-
best-thin-film-transistor-ever.
8) http://pubs.rsc.org/en/content/articlelanding/2010/cs/b909902f#!divAbstract.
9) http://namnak.com/p56497#.
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