Multiple image, single display system and method

Claim 2

A multiple image, single display system characterised by: a display source (4) providing first and second alternating visual images along a light path (12) at a chosen rate and at first and second wavelengths; an active polarizer assembly (14), synchronously coupled to the display source (4) and positioned along the light path (12), which polarizes the first image with a first polarization orientation and the second image with a second polarization orientation; a first, wavelength sensitive user polarizer (16), positioned downstream of the polarizer assembly (14), associated with a first user which blocks transmission of light at about the second wavelength and the second polarization orientation; and a second, wavelength sensitive user polarizer (18), positioned downstream of the polarizer assembly, associated with a second user which blocks transmission of light at about the first wavelength and the first polarization orientation; whereby the first viewer sees the first image but not the second image and the second viewer sees the second image but not the first image without substantially affecting the non-display source vision of the users.

Claim 3

A system as claimed in claim 1, wherein the polarizer assembly (14) includes an image polarizer (20) for initially polarizing both of the first and second images with the first polarization orientation.

Claim 4

A system as claimed in claim 2, wherein the polarizer assembly includes a polarization changer (22), positioned downstream of the image polarizer (20), for changing the polarization of the second image to the second polarization orientation.

Claim 6

A multiple image, single display system characterised by: a time sequential, monochromatic display source (4) providing first and second rapidly alternating visual images at a chosen rate along an image path (12) at first wavelength; an image polarizer (20) positioned along the image path (12) for polarizing the first and second images to a first, circular polarization orientation; a polarization changer (22) positioned along the image path (12) downstream of the image polarizer (20) for changing the circular polarization orientation of light passing along the light path (12) from the first to a second circular polarization orientation when in a first state and for leaving the circular polarization orientation of said light unchanged when in a second state; a synchronizer (28), coupled to the display source (4) and the polarization changer (22), for switching the polarization changer (22) between the first and second states at the chosen rate synchronous with the provision of the first and second images so the first image passing through the polarization changer (22) has its first circular polarization orientation changed to the second polarization orientation and the circular polarization orientation of the second image is unchanged as it passes through the polarization changer; and first and second wavelength-sensitive, user polarizers (16,18), associated with first and second users respectively, which only blocks transmission of light to the first user which is about the second wavelength and has the second circular polarization orientation and only blocks light to the second user which is about the first wavelength and has the first circular polarization orientation; whereby the first user does not see the second image and the second user does not see the first image.

Claim 7

A multiple image, single display system characterised by: a time sequential, monochromatic display source (4) providing first and second rapidly alternating visual images at a chosen rate along an image path (12) at first wavelength; an image polarizer (20) positioned along the image path (12) for polarizing the first and second images to a first, circular polarization orientation; a polarization changer (22) positioned along the image path (12) downstream of the image polarizer (20) for changing the circular polarization orientation of light passing along the light path (12) from the first to a second circular polarization orientation when in a first state and for leaving the circular polarization orientation of said light unchanged when in a second state; a synchronizer (28), coupled to the display source (4) and the polarization changer (22), for switching the polarization changer (22) between the first and second states at the chosen rate synchronous with the provision of the first and second images so the first image passing through the polarization changer (22) has its first circular polarization orientation changed to the second polarization orientation and the circular polarization orientation of the second image is unchanged as it passes through the polarization changer; and first and second wavelength-sensitive, user polarizers (16,18), associated with first and second users respectively, which only blocks transmission of light to the first user which is about the second wavelength and has the second circular polarization orientation and only blocks light to the second user which is about the first wavelength and has the first circular polarization orientation; whereby the first user does not see the second image and the second user does not see the first image.

Claim 10

A method as claimed in claim 6, wherein the projecting step is carried out by alternately projecting the first and second visual images at first and second wavelengths.

Claim 11

A method as claimed in claim 7, wherein the second polarized image blocking step is carried out by blocking transmission of light which has both the second wavelength and the second polarization orientation so that the first viewer sees the first image but not the second image without substantially affecting the non-display source vision of the first viewer.

Claim 12

A method as claimed in claim 8, wherein the first polarized image blocking step is carried out by blocking transmission of light which has both the first wavelength and the first polarization orientation so that the second viewer sees only the second image without substantially affecting the non-display source vision of the second viewer.