Image input-output device with color layer between photodetector and display elements to improve the accuracy of reading images in color
An image input-output device includes a pixel which displays an image and reads an image. The pixel includes a photodetector element, a color layer, and a display element. The color layer is provided over the photodetector element and the display element is provided over the color layer, so that the distance between the photodetector element and the color layer is reduced. Accordingly, light is likely to enter the predetermined photodetector element through the predetermined color layer, and thus, even a color object can be read correctly.
1. An image input-output device comprising:
a substrate; and
a pixel which is provided over the substrate, and configured to display an image and configured to read an image,
wherein the pixel includes:
a first transistor and a second transistor;
a photodetector element having an anode and a cathode, one of which is electrically connected to a gate electrode of the second transistor;
a first protective film provided over the first transistor, the second transistor, and the photodetector element;
a color layer and a light blocking layer provided over and in contact with a top surface of the first protective film, a top surface of the color layer being aligned with a top surface of the light blocking layer;
a second protective film provided over and in contact with a top surface of the color layer and a top surface of the light blocking layer; and
a liquid crystal element provided over the second protective film, and
wherein the liquid crystal element includes:
a first electrode provided over and in contact with a top surface of the second protective film;
a second electrode; and
a liquid crystal layer to which a voltage is configured to be applied by the first electrode and the second electrode.
2. The image input-output device according to claim 1 , wherein the photodetector element includes:
a first semiconductor layer having one of p-type conductivity and n-type conductivity;
a second semiconductor layer which is provided over the first semiconductor layer and has a higher resistance than the first semiconductor layer; and
a third semiconductor layer which is provided over the second semiconductor layer, and has the other of p-type conductivity and n-type conductivity and a lower resistance than the second semiconductor layer.
3. The image input-output device according to claim 1 , wherein the photodetector element includes a semiconductor layer including a first semiconductor region having one of p-type conductivity and n-type conductivity; a second semiconductor region having a higher resistance than the first semiconductor region; and a third semiconductor region having the other of p-type conductivity and n-type conductivity and a lower resistance than the second semiconductor region.
4. The image input-output device according to claim 1 , wherein the photodetector element generates a current in accordance with the illuminance of incident light through the color layer.
5. The image input-output device according to claim 1 , wherein the color layer is a color layer of at least any of red, green, and blue.
6. The image input-output device according to claim 1 , wherein the image input-output device has a function of inputting and outputting text.
7. The image input-output device according to claim 1 , wherein the image input-output device is incorporated into an electronic device selected from the group consisting of a personal digital assistant, an information guide terminal, a laptop personal computer, a portable game machine, a stationary information terminal, and a display.
8. The image input-output device according to claim 1 , wherein the substrate is a flexible substrate.
9. The image input-output device according to claim 1 , wherein the photodetector element overlaps with the second transistor.
10. The image input-output device according to claim 1 , wherein the first electrode overlaps with the photodetector element.
11. An image input-output device comprising:
a substrate; and
a pixel which is provided over the substrate, and configured to display an image and configured to read an image,
wherein the pixel includes:
a first transistor and a second transistor;
a photodetector element having an anode and a cathode, one of which is electrically connected to a gate electrode of the second transistor;
a first protective film provided over the first transistor, the second transistor, and the photodetector element;
a color layer and a light blocking layer having a tapered cross section provided over and in contact with a top surface of the first protective film, a top surface of the color layer being aligned with a top surface of the light blocking layer;
a second protective film provided over and in contact with a top surface of the color layer and a top surface of the light blocking layer; and
a liquid crystal element provided over the second protective film, and
wherein the liquid crystal element includes:
a first electrode provided over and in contact with a top surface of the second protective film;
a second electrode; and
a liquid crystal layer to which a voltage is configured to be applied by the first electrode and the second electrode.
12. The image input-output device according to claim 11 , wherein the photodetector element includes:
a first semiconductor layer having one of p-type conductivity and n-type conductivity;
a second semiconductor layer which is provided over the first semiconductor layer and has a higher resistance than the first semiconductor layer; and
a third semiconductor layer which is provided over the second semiconductor layer, and has the other of p-type conductivity and n-type conductivity and a lower resistance than the second semiconductor layer.
13. The image input-output device according to claim 11 , wherein the photodetector element includes a semiconductor layer including a first semiconductor region having one of p-type conductivity and n-type conductivity; a second semiconductor region having a higher resistance than the first semiconductor region; and a third semiconductor region having the other of p-type conductivity and n-type conductivity and a lower resistance than the second semiconductor region.
14. The image input-output device according to claim 11 , wherein the photodetector element generates a current in accordance with the illuminance of incident light through the color layer.
15. The image input-output device according to claim 11 , wherein the color layer is a color layer of at least any of red, green, and blue.
16. The image input-output device according to claim 11 , wherein the image input-output device has a function of inputting and outputting text.
17. The image input-output device according to claim 11 , wherein the image input-output device is incorporated into an electronic device selected from the group consisting of a personal digital assistant, an information guide terminal, a laptop personal computer, a portable game machine, a stationary information terminal, and a display.
18. The image input-output device according to claim 11 , wherein the substrate is a flexible substrate.
19. The image input-output device according to claim 11 , wherein the photodetector element overlaps with the second transistor.
20. The image input-output device according to claim 11 , wherein the first electrode overlaps with the photodetector element.
21. The image input-output device according to claim 11 , wherein the light blocking layer overlaps with the first transistor.