Liquid crystal display device

#This is a continuation of application Ser. No. 306,352, filed Nov. 13, 1972, and now abandoned.

#Joseph J. Wysocki in U.S. Pat. No. 3,622,224, issued Nov. 23, 1971, discloses a liquid crystal device having a plurality of liquid crystal display cells therein. Transparent electrodes are placed upon adjacent surfaces of transparent panels, with a numeral formed by one of the adjacent transparent electrodes of each cell, and liquid crystal material placed between the adjacent transparent electrodes of each cell. Unpolarized light is passed through the device to read out a numeral. When a voltage is placed onto adjacent transparent electrodes of a cell of the device, the unpolarized light will be scattered by the crystals of the liquid crystal material between the numeral and the other transparent electrode of the selected cell. One can thus see the numeral which has been formed by the transparent electrode of the selected cell.

#The present applicant shows a liquid crystal display device whose crystals rotate polarized light a selected number of times. The device has several liquid crystal display cells therein, each cell having adjacent transparent panels with transparent electrodes thereon, one of the adjacent transparent electrodes forming a numeral or other character. The transparent electrodes have oriented alignment films on them, as described in U.S. patent application Ser. No. 242,675, filed on Apr. 10, 1972 and which issued on Sept. 10, 1974, as U.S. Pat. No. 3,834,792 to the present applicant and assignee to the present assignee. The alignment films influence the rotation of the crystals of the separate liquid crystal display cells by a given angle such as 90.degree. and the rotated liquid crystals rotate polarized light passing through them.

#FIG. 1 is a perspective view of a liquid crystal display device having several numerals housed therein.

#FIG. 2 is a plan view of a numeral 1 formed by a transparent electrode of the device of FIG. 1 having an alignment film thereon.

#FIG. 3 is a plan view of a numeral 7 formed by a transparent electrode of the device of FIG. 1 having an alignment film thereon.

#FIG. 1 is an isometric view which illustrates a fabricated liquid crystal display device 30 having liquid crystal cells 40, 42, 44, 46, 48 and 49 in it. Transparent panels such as glass panels having surfaces 10, 10A, 10B, 10C, 10D, 10E, 10F, 10G, 10H, 10I, 10J and 10K are stacked in the liquid crystal display device 30, and have transparent electrode films 11, 11A, 11B, 11C, 11D, 11E, 11F, 11H, 11I, 11J and 11K respectively on these surfaces. The transparent electrodes may be made of thin tin oxide films, thin indium oxide films or thin cadmium oxide films. Nematic liquid crystal material is placed between adjacent electrode films. The liquid crystal material has elongated crystals in it. A numeral is formed by electrode films 11, 11C, 11D, 11G, 11H and 11K. The surfaces of the electrode films 11, 11C, 11D, 11G, 11H and 11K may be rubbed in a vertical direction in order to align the elongated crystals of the liquid crystal material adjacent to these electrode films in a vertical direction. As an alternative to the rubbing of the electrode films, alignment films as disclosed in U.S. patent application Ser. No. 242,675, filed Apr. 10, 1972 by the present applicant and assigned to the present assignee, may be placed on the electrode films. Vertically polarized light when passed through the elongated crystals of liquid crystal material adjacent to the vertically rubbed electrode films will remain polarized in a vertical direction. The electrode films 11A, 11B, 11E, 11F, 11I and 11J may be rubbed in a horizontal direction. However in this embodiment, instead of these electrode films being rubbed, a thin alignment film whose surface has alignment growth is in a horizontal direction, is placed upon each of these electrode films. The mechanism by which these alignment films align liquid crystals adjacent to them is disclosed in the cited patent application incorporated herein by reference. As vertically polarized light is transmitted through elongated crystals of the liquid crystal material between adjacent vertical and horizontal alignment films, it is rotated into a horizontal plane. The elongated crystals of the liquid crystal material are rotated between the adjacent vertical and horizontal alignment films.

#In FIG. 1, alignment films 16 through 16K are shown deposited respectively upon the electrode films 11 through 11K. The alignment films 16, 16C, 16D, 16G, 16H and 16K respectively have vertical alignment growth 19, 19C, 19D, 19G, 19H and 19K to form vertical alignment directions for crystals of liquid material. The alignment crystal films 16A, 16B, 16E, 16F, 16I and 16J respectively have horizontal alignment growth 19A, 19B, 19E, 19F, 19I and 19J to form horizontal alignment directions for elongated crystals of liquid crystal material. The alignment growth 19 of the alignment film 16 is pointing in a direction at right angle to the direction of the alignment growth 19A of the alignment film 16A, due to arrangement of the surfaces 10 and 10A during the fabrication of the liquid crystal display cell 30. Similarly, the alignment films on surfaces 10E and 10F are in a direction at 90.degree. with respect to the direction of alignment films on surfaces 10D and 10G. Further, the alignment films on surfaces 10I and 10J are in a direction at 90.degree. with respect to the direction of the alignment on surfaces 10H and 10K.

#As shown in FIG. 1 nematic liquid crystal material 22, such as nematic bilevel material, which may be a mixture by weight of 32% methoxybenzilidene-n-butylaniline, 58% ethoxybenzilidene-n-butylaniline and 10% p-n-butoxybenzilidene-p'-aminobenzonitrile, is used between the silicon monoxide alignment films 16 and 16A prior to final sealing of the liquid crystal display device 30. A sealer is then placed around the periphery of the glass surfaces 10 and 10A to seal liquid crystal material 22 within a formed liquid crystal display cell 40. Similarly, liquid crystal materials 22A, 22B, 22C, 22D and 22E is placed between the alignment films on the other panels of the liquid crystal display device 30 to form liquid crystal display cells 42, 44, 46, 48 and 49. One-half mil thick spacers separate each two adjacent alignment films. Elongated crystals of the liquid crystal material 22 in the liquid crystal display cell 40 have their longitudinal axes aligned sympathetically to the direction of the silicon monoxide film alignment growth 19 interfacing alignment film 16, and elongated crystals of the liquid crystal material 22 in the corresponding liquid crystal display cell 40 have their longitudinal axes aligned in a direction parallel to the direction of the platinum film alignment growth 19A interfacing the alignment film 16A. The liquid crystal material 22 will thus rotate or twist vertically polarized light passing through the cell 40 by 90.degree. since the elongated crystals of the liquid crystal material 22 of the liquid crystal display cell 40 are rotated by 90.degree. across cell 40. Similarly, liquid crystal materials 22A, 22B, 22C, 22D and 22E of cells 42, 44, 46, 48 and 49 will rotate polarized light passed through each of them, by 90.degree., since the elongated crystals of the liquid crystal material of cells 42, 44, 46, 48 and 49 of liquid crystal display device 30 are rotated by 90.degree..