Color filter grouping for addressing matrixed display devices

• US 4,855,724 A
• Filed: 03/23/1987
• Issued: 08/08/1989
• Est. Priority Date: 03/23/1987
• Status: Expired due to Fees

• Current Assignee: Tektronix Incorporated (Fortive Corp.)
• Original Assignee: Tektronix Incorporated (Fortive Corp.)
• Inventors: Yang, Kei-Wean C.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/028,930
• Time in Patent Office: 869 Days
• Field of Search: 340/701, 340/703, 340/784, 340/783, 340/811, 340/802, 340/805, 350/339 F, 350/339 R, 350/332, 350/333, 350/334, 350/330, 350/331 R, 358/59
• US Class Current: 345/88
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: H04N 3/127 using liquid crystals

Abstract

A matrixed display device comprises a plurality of monochrome optical bodies arranged in a matrix of intersecting horizontal rows and vertical columns and an optical bandpass filter element associated with each such body. The filter elements are in first, second and third arrays, passing red light, green light and blue light respectively. In each row and column of the matrix, a filter element of one of the three arrays is located between filter elements of the other two arrays. With this arrangement of filter elements, a color pixel can be formed by selectively stimulating first and second monochrome optical bodies that are adjacent each other in a first row of the matrix and a third monochrome optical body that is in a row adjacent the first row and is in the same column as one of the first and second optical bodies.

Claims

1. Matrixed display apparatus comprising:

a matrixed display device having a plurality of optical structures arranged in a matrix of intersecting rows and columns, each optical structure being actuable to control the propagation of light towards a viewer of the device, the optical structures being in first, second and third distinct arrays associated with first, second and third regions respectively of the optical spectrum, and each optical structure in a given array being selectively actuable to propagate light in the associated region of the optical spectrum towards a viewer of the device and being operative to not propagate light in the other regions of the optical spectrum towards the viewer, the first, second and third arrays being such that each optical structure in each array is one structure in a group of three structures, in the first, second and third arrays respectively, with the optical structures in the first and second arrays being in one row of the matrix and the optical structure in the third array being in a row adjacent said one row and in the same column as the optical structure in one of the first and second arrays,

a video processor for receiving an input video signal composed of a succession of active line intervals and providing an output video signal having two active line intervals during a period corresponding to one active line interval of the input video signal, and the video processor also being operative to provide at least two output timing signals,

selection means functionally coupled to the optical structures and operative in response to the output timing signals to select each row of optical structures for a period substantially equal to the active line interval of the output video signal, the rows being selected consecutively, and to select the optical structures in a selected row consecutively within the period for which that row is selected, and

actuation means responsive to the output video signal for actuating a selected optical structure.

2. Apparatus according to claim 1, wherein each optical structure comprises an optical body that is switchable between a first condition in which it blocks transmission of light and a second condition in which it is able to transmit light in all of the first, second and third regions of the optical spectrum, and a bandpass filter element which has a substantially higher transmission for one region of the spectrum than for the other regions of the spectrum.

3. Apparatus according to claim 2, wherein each optical body is a volume of liquid crystal material, and the selection means comprise first and second sets of electrodes arranged in crossing relationship for applying an electric field selectively to the respective volumes of liquid crystal material.

4. Apparatus according to claim 2, wherein each optical body is a volume of electroluminescent material, and the selection means comprise first and second sets of electrodes arranged in crossing relationship for applying an electric field selectively to the respective volumes of electroluminescent material.

5. Apparatus according to claim 1, wherein the selection means comprise a set of row electrodes and a set of column electrodes arranged in crossing relationship, with the optical structures being at the crossing areas of the row and column electrodes, so that by selecting one row electrode and one column electrode the optical structure at the crossing area of said one row electrode and said one column electrode may be actuated, and the selection means also comprising row select means for sequentially selecting the row electrodes, and column select means for sequentially selecting the column electrodes.

6. Apparatus according to claim 5, wherein the number of row electrodes is 2m, where m is an integer greater than zero, the number of column electrodes is 3n, where is an integer greater than zero, the output video signal is composed of first, second and third color component signals, corresponding to the first, second and third arrays respectively, and the actuation means comprise a multiplexer having first, second and third output terminals, and 3n switches connected to the column electrodes respectively, the (3j+1)th switch, where j is an integer from zero to (n-1), being connected to the first output terminal of the multiplexer, the (3j+2)th switch being connected to the second output terminal of the multiplexer, and the (3j+3) th switch being connected to the third output terminal of the multiplexer, the column select means being operative to render the switches conductive sequentially and thereby select the column electrodes sequentially, and the multiplexer having a first state in which the first, second and third color component signals are applied to the first, second and third output terminals respectively and a second state in which the first, second and third component signals are applied to the second, third and first output terminals respectively, the multiplexer being placed in its first state when the row select means select the (2k-1)th row electrode, where k is an integer from 1 to m, and being placed in the second state when the row select means select the 2kth row electrode.

7. Apparatus according to claim 1, wherein the video processor comprises first and second memory portions and is operative during a first active line interval of the input video signal to write the input video signal into the first memory portion and during a second active line interval of the input video signal to write the input video signal into the second memory portion and concurrently read the contents of the first memory portion twice in succession.

8. A method of addressing a matrixed display device comprising a plurality of optical structures arranged in a matrix of intersecting rows and columns, each optical structure being actuable to control the propagation of light towards a viewer of the device, the optical structures being in first, second and third arrays associated with different respective regions of the optical spectrum, and each optical structure in a given array being selectively actuable to propagate light in the associated region of the optical spectrum towards a viewer of the device and being operative to not propagate light in the other regions of the optical spectrum towards the viewer, the first, second and third arrays being such that each optical structure in each array is one structure in a group of three structures, in the first, second and third arrays respectively, with two of the three optical structures being in one row of the matrix and one of the optical structures being in a row adjacent said one row and in the same column of the matrix as one of said two optical structures, and selection means for selecting the optical structures for actuation, said method comprising:

providing a first video signal composed of a succession of active line intervals,

employing the first video signal to generate a second video signal having two active line intervals during a period corresponding to one active line interval of the first video signal,

selecting the rows of the matrix consecutively during respective active line intervals of the second video signal,

sequentially selecting the optical structures in the selected row, and

employing the second video signal to actuate selectively the optical structures.

9. A method according to claim 8, wherein the second video signal is generated by writing the first video signal into a first memory portion during a first active line interval of the first video signal, writing the first video signal into a second memory portion during a second active line interval of the first video signal, and concurrently reading the contents of the first memory portion twice in succession and thereby providing two active lines of the second video signal.

10. The method according to claim 9, wherein m consecutive active lines of the first video signal, where m is an integer greater than zero, form a field of the first video signal, whereby each field of the second video signal is composed of 2m consecutive active lines, and the number of rows in the matrix is 2m.