In recent years, progress has been made in the research and development of display devices that use the phenomenon of electroluminescence occurring in organic material.  Each light-emitting cell of such a display device is composed of an anode and a cathode with an organic light-emitting layer therebetween.  When the display device is driven, holes are injected through the anode, electrons are injected through the cathode, and the holes and electrons recombine within the organic light-emitting layer, thereby emitting the light. 
Banks composed of insulating material partition the organic light-emitting layer into light-emitting cells.  The organic light-emitting layer is formed by dripping ink, which includes an organic light-emitting material, into each region separated by the banks and drying the ink. 
Meanwhile, a problem with the organic light-emitting layer formed in this way is that it is difficult for the layer to have a uniform film thickness. 
As one example of technologies for evening out the film thickness of the organic light-emitting layer, Patent Literature 1 discloses providing a convexity on the inner sidewall of the bank in order to control the pinning location of the ink.  In other words, according to the technology of Patent Literature 1, the pinning location of the ink dripped in one light-emitting cell can be set to the convexity.  With this technology, it is possible to secure a uniform film thickness to a certain degree.