BACKGROUND

Field

The invention relates generally to a display device, and, more particularly, to a display device including a fingerprint sensor.

Discussion of the Background

As interest in displays and demand for portable information media have increased, research in and commercialization of display devices have been attracted more attention.

Recently, a display device including a touch sensor for inputting a touch of a user has been commercialized. Accordingly, the user is more conveniently capable of using the display device through the touch sensor.

In addition, recently, a display device with a reinforced security function using fingerprints has been developed.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concepts, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

SUMMARY

Display devices constructed according to the principles of the invention are capable of enhancing a security function of the display device by including a fingerprint sensor having improved sensitivity.

In addition, display devices constructed according to the principles of the invention having improved fingerprint sensor sensitivity may be flexible display devices and may be capable of sensing a touch position and a touch pressure.

Additional aspects will be set forth in the detailed description which follows, and, in part, will be apparent from the disclosure, or may be learned by practice of the inventive concepts.

According to one aspect of the invention, a display device includes: a substrate including a first area having a first light transmittance and a second area adjacent to the first area having a second light transmittance; a plurality of pixels disposed on a first surface of the substrate; and a fingerprint sensor disposed in the first area on a second surface of the substrate. The first light transmittance is greater than the second light transmittance.

The plurality of pixels may include at least one first pixel in the first area and a second pixel in the second area.

The first pixel may include a light emitting area in which an image is displayed and a light transmission area in which a light is transmitted therethrough.

The first pixel may include at least one first sub-pixel disposed in the light emitting area. The first sub-pixel may include a first electrode disposed on the substrate; an emission layer disposed on the first electrode; and a second electrode disposed on the emission layer.

The display device may further include an insulating layer disposed between the substrate and the first electrode, wherein the insulating layer extends into the transmission area. The display device may further include at least one of a pixel defining layer and passivation layer disposed above the substrate, and wherein the insulating layer extends into at least one of the pixel defining layer and the passivation layer. In an exemplary embodiment, the first electrode and the second electrode may extend across the transmission area.

The first sub-pixel may further include at least one structure selected from the group of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer, the at least one structure being disposed between the first electrode and the second electrode, and wherein the at least one structured may extend across the transmission area.

The second pixel may include at least one second sub-pixel, and a size of the first sub-pixel is smaller than a size of the second sub-pixel. According to an exemplary embodiment, each of the first sub-pixel and the second sub-pixel may emit one wavelength of light selected from the group of red light, green light, and blue light.

The size of the first pixel may be the same as the size of the second pixel, and the fingerprint sensor may be a photo sensor or an ultrasonic sensor.

The display device may further include a first sensor disposed on the substrate to sense a touch position input by a user. Further, the first sensor may be a touch sensor of a self-capacitance type or a touch sensor of a mutual-capacitance type. The first sensor may include a first touch electrode; and a second touch electrode spaced apart from the first touch electrode and forming a capacitance with the first touch electrode.

The first touch electrode may have a mesh structure. The first touch electrode may include a conductive polymer.

The display device may further include a second sensor disposed on the first surface of the substrate spaced apart from the first sensor and sensing a touch pressure.

The second sensor may include a conductive polymer.

The first sensor may have a hole in the first area and touch electrodes of the first sensor may be disposed in the second area. Touch electrodes of the second sensor may include a portion in the first area and a portion in the second area.

A sensing type of the first sensor may be different from a sensing type of the second sensor.

At least a portion of the display device may be flexible and be bendable or rollable.

The light transmission area may be free of any light emitting components.

The first surface may include a front surface of the substrate and the second surface comprises a rear surface of the substrate.

According to another aspect of the invention, a display device includes: a substrate including a first area having a first light transmittance and a second area adjacent to the first area having a second light transmittance; a plurality of pixels disposed on a first surface of the substrate; and a first sensor disposed on the first surface of the substrate to sense a touch position; a second sensor disposed on the first surface of the substrate spaced apart from the first sensor to sense pressure applied by touch from a user; and a fingerprint sensor disposed in the first area on a second surface of the substrate. The first area includes a light emitting area configured to display an image and a light transmission area configured to transmit light.

The transmission area may be free of any light emitting components.

According to still another aspect of the invention, a display device includes: a substrate including, in a plan view, a first area and a second area; a first sub-pixel disposed on the substrate, the first sub-pixel including an emission area disposed in the first area; a second sub-pixel disposed on the substrate, the second sub-pixel including an emission area disposed in the second area; a transmission area disposed on the substrate, the transmission area being adjacent to the second sub-pixel disposed in the second area; and a sensor disposed under the substrate, the photo sensor disposed in the second area. The emission area of the first sub-pixel has a first size and the emission area of the second sub-pixel has a second size different from the first size.

The sensor may be a fingerprint sensor.

The fingerprint sensor may be a photo sensor or an ultrasonic sensor.

The display device may further include: an insulating layer on the substrate. The transmission area may be formed by removing at least a portion of the insulating layer.

The second sub-pixel may include: a first electrode disposed on the substrate; an organic layer disposed on the first electrode; and a second electrode disposed on the emission layer. The second electrode may extend from the emission area of the second sub-pixel toward the transmission area, and the transmission area may include an opening formed by the second electrode of the second sub-pixel.

The display device may further include: a third sub-pixel disposed on the substrate, the third sub-pixel including an emission area disposed in the second area. Each of the second sub-pixel and the third sub-pixel may include: a first electrode disposed on the substrate; an emission layer disposed on the first electrode; and a second electrode disposed on the emission layer. The second electrode of the second sub-pixel and the second electrode of the third sub-pixel may be connected, and the transmission area may include an opening formed by the second electrode of the second sub-pixel and the second electrode the third sub-pixel.

The second sub-pixel may include: a first electrode disposed on the substrate; an organic layer disposed on the first electrode; and a second electrode disposed on the emission layer. The organic layer may not overlap the transmission area in the plan view.

At least one of the first electrode and the second electrode may extend into the transmission area and overlap the transmission area in the plan view.

The display device may further include: a touch sensor disposed on the substrate, the touch sensor comprising sensing electrodes. The sensing electrodes may not overlap the transmission area in the plan view.

The first size may be larger than the second size.

According to still another aspect of the invention, a display device includes: a substrate including, in a plan view, a first area and a second area; a first sub-pixel disposed on the substrate, the first sub-pixel including an emission area disposed in the first area; a second sub-pixel disposed on the substrate, the second sub-pixel including an emission area disposed in the second area; a transmission area disposed on the substrate, the transmission area being adjacent to the second sub-pixel disposed in the second area; and a touch sensor disposed on the substrate, the touch sensor comprising sensing electrodes. At least a portion of the second area comprises an area where the sensing electrodes and the transmission area may be not overlapped in the plan view.

The sensing electrodes may be not disposed in the second area.

The sensor may be a fingerprint sensor.

The fingerprint sensor may be a photo sensor or an ultrasonic sensor.

Accordingly, display devices constructed according to the principles of the invention provide an enhanced security function by including an improved fingerprint sensor.

Further, exemplary embodiments of the invention provide a high-quality display device in which resolution of an area including the fingerprint sensor is substantially the same as resolution of an area not including the fingerprint sensor.

In addition, exemplary embodiments of the invention provide a display device which is capable of sensing a touch position and a touch pressure while sensing the fingerprint thereby enhancing convenience of use.

The foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the claimed subject matter.

