CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and claims the benefit of priority from the prior Japanese Patent Application No. 2018-001821, filed on Jan. 10, 2018, and PCT Application No. PCT/JP2018/046170 filed on Dec. 14, 2018, the entire contents of which are incorporated herein by reference.

FIELD

The present invention relates to a display device and a manufacturing method thereof. In particular, it relates to an organic EL display device having flexibility and a manufacturing method thereof.

BACKGROUND

A display device having a plurality of pixels formed on a substrate is known. Typical examples of such display device include a liquid crystal display device and an EL display device.

An EL display device is a display device with a light emitting element having a structure in which a material exhibiting electroluminescence (EL) phenomena is sandwiched between a pair of electrodes in each pixel. A light emitting element, which uses an organic compound as its material, is called an organic light emitting element, an organic EL element, or an organic electric field light emitting element. Such a display device having a plurality of organic light emitting elements is called an organic EL display device.

The organic EL display device has a plurality of organic light emitting elements (hereinafter referred to as a light emitting element) formed on a substrate. The organic EL display device displays images by controlling each light emitting element by a switching element such as a transistor. The substrate can include a glass substrate, a metallic substrate, and a ceramic substrate. By using the substrate having flexibility, for example, the substrate containing plastic resin (polycarbonate, polyethylene terephthalate, polyimide, polyacrylate, and the like), the organic EL display device having flexibility can be manufactured.

Japanese laid-open patent publication No. 2006-322964 discloses a liquid crystal display device comprising a polarizing film having a film-like polarizer, a high brightness film, a viewing angle improving film, or the like on a pair of substrates sandwiching a liquid crystal layer. A liquid crystal display device described in Japanese laid-open patent publication No. 2006-322964, in order to prevent peeling of the film, a thickness of an end portion of the polarizing film has a tapered shape that becomes thinner as it approaches an edge of the polarizing film.

SUMMARY

A display device according to an embodiment of the present invention comprises an organic EL substrate including a flexible substrate and an organic EL layer formed on a first main surface of the flexible substrate; a film covering a display region of the organic EL substrate; and a terminal region arranged at an end portion of the organic EL substrate, and arranged adjacent to and apart from an end portion of the film. The end portion of the film may have a taper region. A thickness of the taper region increases with distance from the terminal region in a cross-sectional view. A width of the taper region may be 0.5 times or more and 1.5 times or less of the film thickness in a plan view.

In the display device according to an embodiment of the present invention, the width of the taper region of the film may be 40 μm or more and 200 μm or less in a plan view.

In the display device according to an embodiment of the present invention, the taper region of the film may be located in a corner portion of the film in a plan view.

The display device according to an embodiment of the present invention comprises an organic EL substrate including a flexible substrate and an organic EL layer formed on a first main surface of the flexible substrate; a film covering a display region of the organic EL substrate; and a terminal region arranged at an end portion of the organic EL substrate, and arranged adjacent to and apart from an end portion of the film. The end portion of the film may have a step region having a thickness smaller than a thickness of the film.

In the display device according to an embodiment of the present invention, the thickness of the step region of the film may be 0.5 times or more and 0.8 times or less of the film thickness.

In the display device according to an embodiment of the present invention, the width of the step region of the film may be 40 μm or more and 200 μm or less from the end of the film in a plan view.

In the display device according to an embodiment of the present invention, the step region of the film may be located in a corner portion of the film in a plan view.

A method for manufacturing a display device according to an embodiment of the present invention comprises forming an organic EL substrate by forming an organic EL layer on a first main surface of a flexible substrate; forming a terminal region in an end portion of the organic EL substrate; covering a display region of the organic EL substrate with a film, cutting the film along a first cutting line by a first laser, and cutting the organic EL substrate along a second cutting line by a second laser. The film has a taper region. A thickness of the taper region increases with distance from the terminal region in a cross-sectional view. A cutting end position may be in a range of the taper region.

In the method for manufacturing a display device according to an embodiment of the present invention, a cutting start position of the film by the first laser may be in a range of the taper region.

A method for manufacturing a display device according to an embodiment of the present invention comprises forming an organic EL substrate by forming an organic EL layer on a first main surface of a flexible substrate; forming a terminal region in an end portion of the organic EL substrate; covering a display region of the organic EL substrate with a film, cutting the film along a first cutting line by a first laser, and cutting the organic EL substrate along a second cutting line by a second laser. The film has the step region. A thickness of the step region is smaller than the thickness of the film. A cutting end position may be in the range of the step region.

