In the related art, various techniques have been proposed for a light control film bonded to, for example, a window and usable in an electronic window blind to control transmission of external light (see Patent Documents 1 and 2). One type of such light control films uses liquid crystals. This type of light control film using liquid crystals is produced by sandwiching a liquid crystal cell between linear polarization films. The liquid crystal cell is produced by sandwiching a liquid crystal material between transparent panels provided with transparent electrodes. As a result, the light control film controls alignment of liquid crystals to shield or transmit external light, and even to change an amount of transmitted light by changing an electric field applied to the liquid crystals and, so that the light control film controls transmission of external light.
In such a light control film, a spacer is provided on a transparent substrate of the liquid crystal cell, so that a thickness of a liquid crystal layer is uniformly maintained by this spacer. In addition, the spacer has a configuration widely used in image display panels. For example, the spacer is produced in a rod shape, for example, using a photoresist.
In addition, a bead spacer may be employed, for example. Patent Documents 3 and 4 propose techniques on the bead spacer.
However, in some of the light control films of the related art, the spacer may collapse or a front end of the spacer may intrude into a facing surface due to a pressing force or the like during use. As a result, in the light control films of the related art, a cell gap has become irregular, or a local alignment failure has occurred. Accordingly, there have been some cases in which it is difficult to uniformly control light and other cases in which a liquid crystal material of the liquid crystal layer leaks. As a result, the light control films of the related art have encompassed drawbacks related to practical usage of the spacer from the viewpoint of reliability.
It may be conceived that such drawbacks may be addressed by a solution to increase the thickness of the spacer or the number of spacers. However, the solution described above may result in a decrease in transmittance or a deterioration in alignment of liquid crystals. In addition, it may be disadvantageous that diffraction light caused by the spacer may be visually recognizable.    Patent Document 1: Japanese Unexamined Patent Application, Publication No. H03-47392    Patent Document 2: Japanese Unexamined Patent Application, Publication No. H08-184273    Patent Document 3: Japanese Unexamined Patent Application, Publication No. S62-286023    Patent Document 4: Japanese Unexamined Patent Application, Publication No. H02-120719
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