Display device having a reservoir and a vacuum channel for filling the display region with the liquid crystal material

Abstract

A liquid crystal display cell comprises first and second substrates located in a substantially parallel relative arrangement to define an active display region therebetween when filled with liquid crystal material. The cell further includes means to effect filling of the active display region with liquid crystal material from at least a part of an edge of the active display region.

I claim: 
     
       1. A cell for a liquid crystal display device, the cell comprising; a first and a second substrate located in a substantially parallel relative arrangement to define an active display region therebetween which can be filled with liquid crystal material, said first and said second substrate being separated in the active display region by a gap having a gap thickness;   a reservoir for filling the active display region with liquid crystal material, the reservoir being positioned intermediate the first and said second substrate and having an outlet port which extends along at least a part of an edge of the active display region, .Iadd.and a vacuum channel for applying a suction pressure between the substrates and extending along at least a part of a further edge of the active display region, .Iaddend.wherein the reservoir .[.has.]. .Iadd.and the vacuum channel each have .Iaddend.a width in the dimension corresponding to said gap .Iadd.thickness .Iaddend.which is greater than said gap thickness.   
     
     
       2. A cell according to claim 1 wherein said outlet port extends along at least a part of at least two edges of the active display region. 
     
     
       3. A cell according to claim 1 wherein the reservoir produces a filling front of liquid crystal material during filling of the cell with liquid crystal material, and the reservoir is adapted so that said filling front is not substantially parallel to a side of at least one of the cell or the active display region thereof. 
     
     
       4. A cell according to claim 1 wherein the outlet port is of said width in the dimension corresponding to said gap which is greater than said gap thickness. 
     
     
       5. A cell according to claim 1 wherein each substrate has an inner surface corresponding to the interior of the cell and at least one of the substrates includes at said inner surface a section indented relative to said inner surface at the active display region of the substrate, thereby to form the reservoir. 
     
     
       6. A cell according to claim 5, said at least one of the substrates having at least one layer for colour filtering in the active display region wherein said at least one layer is positioned to at least contribute to said inner surface at the active display region and hence to the stepped disposition between the active display region and the indented section. 
     
     
       7. A cell according to claim 1 wherein at least one of the substrates includes a portion which has been recessed to form the reservoir. 
     
     
       8. A cell according to claim 1 wherein one of the substrates has an aperture effective as a fill hole in communication with the reservoir. 
     
     
       9. A cell according to claim 1 further comprising a vacuum hole. 
     
     
       10. A cell according to claim 9 wherein the vacuum hole is disposed in one of the substrates. 
     
     
       11. A cell according to claim 9 further comprising a channel of an increased width, in the respective dimension, to the gap between the substrates in the active display region, the channel being in communication with the vacuum hole. 
     
     
       12. A cell according to claim 1 when filled with liquid crystal material. 
     
     
       13. A method of filling a cell for a liquid crystal display device, the cell comprising: a first and a second substrate located in a substantially parallel relative arrangement to define an active display region therebetween which can be filled with liquid crystal material, said first and said second substrate being separated in the active display region by a gap having a gap thickness;   .[.and.]. a reservoir for filling the active display region with liquid crystal material, the reservoir being positioned intermediate said first and said second substrate and having an outlet port which extends along at least a part of an edge of the active display region, .Iadd.and   a vacuum channel for applying a suction pressure between the substrates and extending along at least a part of a further edge of the active display region,   wherein .Iaddend.the reservoir .[.having.]..Iadd.and the channel each have .Iaddend.a width in the dimension corresponding to said gap .Iadd.thickness .Iaddend.which is greater than said gap thickness; .Iadd.and .Iaddend.   wherein the method includes the step of filling the reservoir with liquid crystal material .Iadd.and applying a suction pressure to the vacuum channel, .Iaddend.whereby .[.the cell is filled.]. .Iadd.to fill the cell .Iaddend.with liquid crystal material from at least a part of an edge of the active display region.   
     
     
       14. A method according to claim 13 comprising filling the cell with liquid crystal material from at least a part of at least two edges of the active display region. 
     
     
       15. A method according to claim 13 .[.including the step of varying the.]. .Iadd.the cell having a vacuum hole wherein the filling step includes applying a .Iaddend.suction pressure .[.applied.]. to the vacuum .[.channel.]. .Iadd.hole .Iaddend.whereby .[.to control.]. the rate at which the cell is filled .Iadd.may be controlled. .Iaddend. .Iadd.16. A cell according to claim 5, wherein at least one of the substrates includes at said inner surface a section indented relative to said inner surface at the active display region of the substrate, thereby to form the channel..Iaddend. .Iadd.17. A cell according to claim 1, wherein one of the substrates has an aperture effective as a vacuum hole in communication 
     
     
        with the channel..Iaddend. .Iadd.18.  A method according to claim 13 including the step of varying the suction pressure applied to the vacuum channel for controlling the rate at which the cell is filled..Iaddend.