TECHNICAL FIELD

One embodiment of the present invention relates to a display device.

Note that one embodiment of the present invention is not limited to the above technical field. The technical field of one embodiment of the invention disclosed in this specification and the like relates to an object, a method, or a manufacturing method. Another embodiment of the present invention relates to a process, a machine, manufacture, or a composition (composition of matter). Specifically, examples of the technical field of one embodiment of the present invention disclosed in this specification include a semiconductor device, a display device, a liquid crystal display device, a light-emitting device, a lighting device, a power storage device, a memory device, an imaging device, a driving method thereof, and a manufacturing method thereof.

In this specification and the like, a semiconductor device generally means a device that can function by utilizing semiconductor characteristics. A transistor and a semiconductor circuit are embodiments of semiconductor devices. In some cases, a memory device, a display device, an imaging device, or an electronic device includes a semiconductor device.

BACKGROUND ART

A widely known semiconductor thin film that can be used for the transistor is a silicon-based semiconductor material; an oxide semiconductor has attracted attention as another material. As the oxide semiconductor, not only single-component metal oxides, such as indium oxide and zinc oxide, but also multi-component metal oxides are known. Among the multi-component metal oxides, in particular, an In—Ga—Zn oxide (hereinafter also referred to as IGZO) has been actively studied.

From the researches on IGZO, a CAAC (c-axis aligned crystalline) structure and an nc (nanocrystalline) structure, which are not single crystal nor amorphous, have been found in an oxide semiconductor (see Non-Patent Document 1 to Non-Patent Document 3). Non-Patent Document 1 and Non-Patent Document 2 also disclose a technique for fabricating a transistor using an oxide semiconductor having a CAAC structure. Moreover, Non-Patent Document 4 and Non-Patent Document 5 show that a fine crystal is included even in an oxide semiconductor which has lower crystallinity than the CAAC structure or the nc structure.

In addition, a transistor that uses IGZO for an active layer has an extremely low off-state current (see Non-Patent Document 6), and an LSI and a display utilizing the characteristics have been reported (see Non-Patent Document 7 and Non-Patent Document 8).

In addition, Patent Document 1 discloses a memory device using a transistor with an extremely low off-state current in a memory cell.

PRIOR ART DOCUMENT

Patent Document

[Patent Document 1] Japanese Published Patent Application No. 2011-119674

Non-Patent Document

[Non-Patent Document 1] S. Yamazaki et al., “SID Symposium Digest of Technical Papers”, 2012, volume 43, issue 1, p. 183-186.[Non-Patent Document 2] S. Yamazaki et al., “Japanese Journal of Applied Physics”, 2014, volume 53, Number 4S, p. 04ED18-1-04ED18-10.[Non-Patent Document 3] S. Ito et al., “The Proceedings of AM-FPD′13 Digest of Technical Papers”, 2013, p. 151-154.[Non-Patent Document 4] S. Yamazaki et al., “ECS Journal of Solid State Science and Technology”, 2014, volume 3, issue 9, p. Q3012-Q3022.[Non-Patent Document 5] S. Yamazaki, “ECS Transactions”, 2014, volume 64, issue 10, p.

155-164.[Non-Patent Document 6] K. Kato et al., “Japanese Journal of Applied Physics”, 2012, volume 51, p. 021201-1-021201-7.[Non-Patent Document 7] S. Matsuda et al., “2015 Symposium on VLSI Technology Digest of Technical Papers”, 2015, p. T216-T217.[Non-Patent Document 8] S. Amano et al., “SID Symposium Digest of Technical Papers”, 2010, volume 41, issue 1, p. 626-629.

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

The resolution of display devices has been increased; hardware capable of displaying images of an 8K4K (the number of pixels: 7680×4320) or higher resolution has been developed. In addition, the HDR (high dynamic range) display technique, which increases image quality by luminance adjustment, has been introduced.

In addition, for proper display by a display device, it is necessary to adjust image data with the resolution of the display device. In the case where the display device has an 8K4K resolution and the image data is for a 4K2K (the number of pixels: 3840×2160) resolution, for example, the number of data should be converted by a fourfold increase to perform full-screen display. In contrast, in the case where the display device has the 4K2K resolution and the image data is for the 8K4K resolution, the number of data should be converted into a quarter.

In HDR processing, a dedicated circuit is necessary for generation of image data or conversion of the number of data, which causes a problem of higher power consumption. It is preferable that at least original image data be input to pixels in the display device without conversion.

Thus, an object of one embodiment of the present invention is to provide a display device capable of improving image quality. Another object of one embodiment of the present invention is to provide a display device capable of performing proper display without image data conversion. Another object is to provide a display device capable of performing HDR display. Another object is to provide a display device capable of performing an upconversion operation. Another object is to provide a display device capable of improving the luminance of a displayed image. Another object is to provide a display device capable of displaying two or more images superimposed on each other. Another object is to provide a display device in which a voltage higher than the output voltage of a driver circuit can be applied to a pixel circuit.

Another object is to provide a display device with low power consumption. Another object is to provide a highly reliable display device. Another object is to provide a novel display device or the like. Another object is to provide a method for driving any of the display devices. Another object is to provide a novel semiconductor device or the like.

Note that the descriptions of these objects do not disturb the existence of other objects. One embodiment of the present invention does not have to achieve all the objects. Other objects will be apparent from and can be derived from the descriptions of the specification, the drawings, the claims, and the like.

Means for Solving the Problems

One embodiment of the present invention relates to a display device capable of improving image quality. Alternatively, one embodiment of the present invention relates to a display device capable of performing image processing.

One embodiment of the present invention is a display device including a plurality of capacitors, a plurality of transistors, and a display element. The plurality of capacitors are connected in series through a wiring. One of the transistors is electrically connected to one electrode of the plurality of capacitors connected in series. One of the transistors is electrically connected to the other electrode of the plurality of capacitors. The display element is electrically connected to the other electrode of the plurality of capacitors connected in series. One of the transistors is electrically connected to the wiring.

Another embodiment of the present invention is a display device including a first transistor, a second transistor, a third transistor, a first capacitor, a second capacitor, and a circuit block. One of a source and a drain of the first transistor is electrically connected to one electrode of the first capacitor. The one electrode of the first capacitor is electrically connected to the circuit block. The other electrode of the first capacitor is electrically connected to one of a source and a drain of the second transistor. The one of the source and the drain of the second transistor is electrically connected to one electrode of the second capacitor. The other electrode of the second capacitor is electrically connected to one of a source and a drain of the third transistor. The circuit block includes a display element.

The display device may further include a first wiring. The other of the source and the drain of the first transistor may be electrically connected to the first wiring, and the other of the source and the drain of the third transistor may be electrically connected to the first wiring.

The display device may further include a fourth transistor, a fifth transistor, a second wiring, and a third wiring. One of a source and a drain of the fourth transistor may be electrically connected to the one electrode of the second capacitor. One of a source and a drain of the fifth transistor may be electrically connected to the other electrode of the second capacitor. The other of the source and the drain of the second transistor may be electrically connected to the first wiring. A gate of the first transistor may be electrically connected to the second wiring. A gate of the fourth transistor may be electrically connected to the second wiring. A gate of the second transistor may be electrically connected to the third wiring. A gate of the fifth transistor may be electrically connected to the third wiring.

Another embodiment of the present invention is a display device including a first circuit, a second circuit, a second transistor, a third transistor, and a second capacitor. The first circuit and the second circuit each include a first transistor, a first capacitor, and a circuit block. One of a source and a drain of the first transistor is electrically connected to one electrode of the first capacitor. The one electrode of the first capacitor is electrically connected to the circuit block. The other electrode of the first capacitor is electrically connected to one of a source and a drain of the second transistor. The one of the source and the drain of the second transistor is electrically connected to one electrode of the second capacitor. The other electrode of the second capacitor is electrically connected to one of a source and a drain of the third transistor. The circuit block includes a display element.

The display device may further include a first wiring. The other of the source and the drain of the first transistor included in the first circuit may be electrically connected to the first wiring, and the other of the source and the drain of the third transistor may be electrically connected to the first wiring.

The display device may further include a fourth transistor, a fifth transistor, a second wiring, and a third wiring. One of a source and a drain of the fourth transistor may be electrically connected to the one electrode of the second capacitor. One of a source and a drain of the fifth transistor may be electrically connected to the other electrode of the second capacitor. The other of the source and the drain of the second transistor may be electrically connected to the first wiring. A gate of the first transistor included in the first circuit may be electrically connected to the second wiring. A gate of the first transistor included in the second circuit may be electrically connected to the second wiring. A gate of the fourth transistor may be electrically connected to the second wiring. A gate of the second transistor may be electrically connected to the third wiring. A gate of the fifth transistor may be electrically connected to the third wiring.

The circuit block includes a sixth transistor, a seventh transistor, a third capacitor, and an EL element as the display element, and may have the following structure: one electrode of the EL element is electrically connected to one of a source and a drain of the seventh transistor; the other of the source and the drain of the seventh transistor is electrically connected to one electrode of the third capacitor; the one electrode of the third capacitor is electrically connected to one of a source and a drain of the sixth transistor; a gate of the sixth transistor is electrically connected to the other electrode of the third capacitor; and the other electrode of the third capacitor is electrically connected to the one electrode of the first capacitor.

Alternatively, the circuit block includes a fourth capacitor and a liquid crystal element as the display element, and may have the following structure: one electrode of the liquid crystal element is electrically connected to one electrode of the fourth capacitor; and the one electrode of the fourth capacitor is electrically connected to the one electrode of the first capacitor.

The display device may further include an eighth transistor. The one electrode of the fourth capacitor may be electrically connected to one of a source and a drain of the eighth transistor, and the other of the source and the drain of the eighth transistor may be electrically connected to the one electrode of the first capacitor.

It is preferable that the first transistor include a metal oxide in a channel formation region and that the metal oxide include In, Zn, and M (M is Al, Ti, Ga, Sn, Y, Zr, La, Ce, Nd, or Hf).

Effect of the Invention

With the use of one embodiment of the present invention, a display device capable of improving higher image quality can be provided. Alternatively, a display device capable of performing proper display without image data conversion can be provided. Alternatively, a display device capable of performing HDR display can be provided. Alternatively, a display device capable of performing an upconversion operation can be provided. Alternatively, a display device capable of improving the luminance of a displayed image can be provided. Alternatively, a display device capable of displaying two or more images superimposed on each other can be provided. Alternatively, a display device in which a voltage higher than the output voltage of a driver circuit can be applied to a pixel circuit can be provided.

Alternatively, a display device with low power consumption can be provided. Alternatively, a highly reliable display device can be provided. Alternatively, a novel display device or the like can be provided. Alternatively, a method for driving any of the display devices can be provided. Alternatively, a novel semiconductor device or the like can be provided.

