Optical system for projection television

For use in an ultra-compact, rear-projection television receiver, a projection optical system protractible and retractible within a narrow spatial column for emerging from and nesting within a cabinet of said receiver, said optical system comprising in combination:

• a stationary optical assembly permanently enclosed in a lower portion of said cabinet, said assembly including:
• image projection means including three cathode ray picture tubes for forming, respectively, a red image, a green image, and a blue image analagous to a composite color television picture, each tube having associated projection lens means in a substantially common axis therewith for projecting an aerial image a predetermined image projection distance along an optical path folded by optical path folding means into coincidence with others of said images to form said color television picture, each of said common axes being oriented at a common, predetermined, steeply upward projection angle;
• first mirror means mounted closely adjacent to said image projection means for receiving said aerial images, said first mirror means being oriented at a fixed predetermined first mirror reflection angle effective to reflect said aerial images steeply upwardly along said folded optical path;
• a protractible optical assembly elevatable as a unit from said cabinet including:
• second mirror means located over said image projection means for receiving said aerial images reflected from said first mirror means when said protractible optical assembly is protracted, said second mirror means being at a fixed predetermined second mirror reflection angle effective to reflect said aerial images forwardly, and when said protractible optical assembly is retracted, said predetermined second mirror reflection angle provides for angular conformance with said projection angle of said image projection means effectively permitting nesting of said second mirror means with said image projection means;
• rear projection screen means, said screen means being located appreciably forwardly of said second mirror means and vertically arranged for receiving, when said protractible optical assembly is protracted, said aerial images reflected from said second mirror means, and when said protractible optical assembly is retracted, said screen means is vertically arranged for nesting between a front panel of said cabinet and said first mirror means;
• said projection angle of said image projection means, and said predetermined first and second mirror reflection angles being such that said protractible optical assembly, when retracted and nested, is overall depth-wise-shallow, and said receiver is as compact as a conventional, large-screen console television receiver, and when said protractible optical assembly is protracted within said narrow spatial column for operation, said receiver remains depth-wise-shallow, yet is capable of displaying an image with an area greater than three times the image area of said conventional console television receiver.

In an ultra-compact, rear projection television receiver having a projection optical system protractible and retractible within a narrow spatial column for emerging from and nesting within a cabinet of said receiver, said optical system providing for projecting, when protracted, at least one television image along a folded optical path folded by optical path folding means onto a rear projection screen of said receiver, said optical system including at least one cathode ray picture tube permanently enclosed in a lower portion of said cabinet and having a cathodoluminescent screen on the inner surface of its face panel for forming said television image, said tube having associated projection lens means on a common axis therewith, said projection, lens having a front face and a rear face located about twelve-hundredths of an inch from said face panel of said tube, said projection lens providing for projecting an aerial image of said television image a predetermined image projection distance of about fifty-eight inches along said optical path and onto said rear projection screen, said path including a first mirror and a second mirror for sequentially reflecting said image along said optical path into coincidence on said rear projection screen, said receiver being characterized by the components of said optical system having the following dimensional and angular parameters, as measured epicentrially from or with respect to x (horizontal) and y (vertical) coordinates crossing at the center point of said rear face of said projection lens, and in the plane of the projection axis of said lens:

• (a) the center point of the front surface of said projection lens being about seven inches from the y axis, and about four point four inches from the x axis, and with said common axis being at an angle of about thirty-three degrees with respect to the x axis;
• (b) the angle of the face of said first mirror being about fourteen degrees with respect to the y axis, and with the image center point being about eleven inches from the y axis, and about seven inches from the x axis;
• (c) the angle of the face of said second mirror being about thirty-one degrees with respect to the y axis, and with the image center point being about three inches from the y axis and about thirty-two inches from the x axis;
• (d) the angle of said rear projection screen being about zero degrees with respect to the y axis, and with its image center point being about 14 inches from the y axis, and about thirty-two inches from the x axis.

In an ultra-compact projection television receiver having a projection optical system protractible and retractible within a narrow spatial column and selectively storable in a cabinet of said receiver for projecting when protracted, red, green and blue television images along a folded optical path about fifty-eight inches in length into coincidence on a rear projection screen, said projection optical system including three cathode ray picture tubes arranged in line and permanently stored in a lower portion of said cabinet, each with a cathodoluminescent screen on the inner surface of its face panel for forming one of said television images, with the projection axis of the center one of said tubes being coincident with the axis of said screen, and the projection axis of each off-axis tube being at an angle of about five point seven degrees with respect to said axis of said screen, each of said tubes having an associated projection lens on a substantially common axis therewith including a front face and a rear face about twelve-hundredths of an inch from the associated face panel, said projection lenses providing for projecting aerial images of the television images formed by said tubes along said folded optical path, said path including a first mirror and a second mirror for sequentially reflecting said aerial images along said optical path into coincidence on said rear projection screen, said projection, television receiver being characterized by said projection optical system having the following dimensional or angular parameters, as measured epicentrally from with respect to x (horizontal) and y (vertical) coordinates crossing at the center point of the rear surface of the lens for the center one of said tube, and in the plane of the respective projection axis of said lens:

• (a) the center point of the front surface of said projection lens being about seven includes from the y axis, and about four point four inches from the x axis, and with said common axis being at an angle of about thirty-three degrees with respect to the x axis;
• (b) the angle of the face of the first mirror being about fourteen degrees with respect to the y axis, and with the image center point being about seven inches from the x axis;
• (c) the angle of the face of said second mirror being about thirty-one degrees with respect to the y axis, and with the image center point being about three inches from the y axis and about thirty-two inches from the x axis;
• (d) the angle of said rear projection screen being about zero degrees with respect to the y axis, and with its image center point being about fourteen inches from the y axis, and about thirty-two inches from the x axis.

In an ultra-compact projection television receiver having a projection optical system protractible and retractible within a narrow spatial column and selectively storable in a cabinet of said receiver for projecting when protracted, red, green and blue television images along a folded optical path about fifty-eight inches in length into coincidence on a rear projection screen, said projection optical system including three cathode ray picture tubes arranged in line and permanently stored in a lower portion of said cabinet, each with a cathodoluminescent screen on the inner surface of its face panel for forming one of said television images, with the projection axis of the center one of said tubes being coincident with the axis of said screen, and the projection axis of each off-axis tube being at an angle of about five point seven degrees with respect to said axis of said screen, each of said tubes having an associated projection lens on a substantially common axis therewith including a front face and a rear face about twelve-hundredths of an inch from the associated face panel, said projection lenses providing for projecting aerial images of the television images formed by said tubes along said folded optical path, said path including a first mirror and a second mirror for sequentially reflecting said aerial images along said optical path also coincidence on said rear projection screen, said projection television receiver being characterized by said projection optical system having the following dimensional or angular parameters, as measured epicentrally from or with respect to x (horizontal) and y (vertical) coordinates crossing at the center point of the rear surface of the lens for the center one of said tubes, and in the plane of the respective projection axis of each lens:

• (a) the center point of the front surface of the center one of said projection lenses being about seven inches from the y axis, and about four point four inches from the x axis, and with said common axis being at an angle of about thirty-three degrees with respect to the x axis;
• (b) the angle of the face of the first mirror being about fourteen degrees with respect to the y axis, and with the image center point being about eleven inches from the y axis, and about seven inches from the x axis;
• (c) the angle of the surface of said second mirror being about thirty-one degrees with respect to the y axis, and with the image center point being about three inches from the y axis and about thirty-two inches from the x axis;
• (d) the angle of said rear projection screen being about zero degrees with respect to the y axis, and with its image center point being about fourteen inches from the y axis, and about thirty-two inches from the x axis.

A method for providing a projection optical system protractible within a narrow spatial column for emerging from the cabinet of an ultra-compact, rear-projection television receiver for receiver operation, and retractible and nestable within the cabinet for storing, the method comprising:

• permanently enclosing a stationary optical assembly in a lower portion of said cabinet;
• including image projection means in said stationary optical assembly, said image projection means having at least one cathode ray tube means for forming a television image;
• associating with said cathode ray tube means, and on a common projection axis therewith, projection lens means for projecting an aerial image of said television image along a folded optical path formed by optical path folding means when said optical system is protracted;
• orienting said projection axis of said image projection means steeply upwardly;
• providing first mirror means closely adjacent to said image projection means for receiving said aerial image;
• nearly-vertically orienting said first mirror means to provide a first mirror angle effective to reflect said aerial image steeply upwardly;
• providing second mirror means at an angle in substantial conformance with the projection axis of said image projection means, and effective to reflect said aerial image forwardly;
• vertically arranging rear projection screen means appreciably forward of said second mirror means for receiving and displaying said aerial image;
• such that when said optical system is protracted, said steeply upward projection angle of said image projection means said first mirror angle, and said angle of said second mirror provide for containment of said optical system in said narrow spatial column, and when said optical system is retracted, the angular conformance of said second mirror means with said image projection means provides for nesting therewith, and the vertical orientation and forward location of said screen provides for the nesting of said screen means with said near-vertically oriented first mirror means.

A method for providing a projection optical system protractible within a narrow spatial column for emerging from the cabinet of an ultra-compact, rear-projection television receiver for receiver operation, and retractible and nestable within the cabinet for storing, the method comprising:

• permanently enclosing a stationary optical assembly in a lower portion of said cabinet;
• including image projection means in said stationary optical assembly, said image projection means including three cathode ray picture tubes for forming, respectively, a red image, a green image, and a blue image;
• associating with each of said tubes, and on a substantially common projection axis therewith, projection lens means for projecting aerial images of said red, green and blue images along a folded optical path folding means when said optical system is protracted;
• orienting said projection axes of said image projection means steeply upwardly;
• providing first mirror means closely adjacent to said image source means for receiving said aerial images;
• nearly-vertically orienting said first mirror means to provide a first mirror angle effective to reflect said aerial images steeply upwardly;
• providing second mirror means for receiving said aerial images reflected from said first mirror means, and locating said mirror means over said image projection means;
• orienting said second mirror means at an angle in substantial conformance with the projection axes of said image projection means, and effective to reflect said aerial images forwardly;
• vertically arranging a rear projection screen means appreciably forward of said second mirror means for receiving and displaying in coincidence with aerial images;
• such that when said optical system is protracted, said steeply upward projection angle of said image projection means said first mirror angle, and said angle of said second mirror provide for containment of said optical system in said narrow spatial column, and when said optical system is retracted, the angular conformance of said second mirror means with said image projection means provides for nesting therewith, and the vertical orientation and forward location of said screen means provides for the nesting of said screen means with said near-vertically oriented first mirror means.

A method for providing a projection optical system protractible within a narrow spatial column for emerging from the cabinet of an ultra-compact, rear-projection television receiver for receiver operation, and retractible and nestable within the cabinet for storing, the method comprising:

• permanently enclosing a stationary optical assembly in a lower portion of said cabinet;
• including image projection means in said stationary optical assembly, said image projection means including three cathode ray picture tubes for forming, respectively, a red image, a green image, and a blue image;
• associating with each of said tubes and on a substantially common projection axis therewith, projection lens means for projecting aerial images of said red, green and blue images along a folded optical path formed by optical path folding means when said optical system is protracted;
• orienting said projection axes of said image projection means at an upward projection angle of about thirty-three degrees with respect to the horizontal;
• providing first mirror means closely adjacent to said image projection means for receiving said aerial images;
• orienting said first mirror means to provide a first mirror angle effective to reflect said aerial images steeply upwardly, said angle being about fourteen degrees with respect to the vertical;
• providing second mirror means for receiving said aerial images reflected from said first mirror means, and locating said mirror means over said image projection means;
• orienting said second mirror means at an angle in substantial conformance with the projection axes of said image projection means, and effective to reflect said aerial images forwardly, said angle being about thirty-one degrees with respect to the horizontal;
• vertically arranging a rear projection screen means appreciably forward of said second mirror means for receiving and displaying in coincidence said aerial images;
• such that when said optical system is protracted, said steeply upward projection angle of said image projection means said first mirror angle, and said angle of said second mirror provide for containment of said optical system said narrow spatial column, and when said optical system is retracted, the angular conformance of said second mirror means with said image projection means provides for nesting therewith, and the vertical orientation and forward location of said screen means provides for the nesting of said screen means with said near-vertically oriented first mirror means.