Wide screen image projection apparatus

• US 4,385,324 A
• Filed: 11/16/1981
• Issued: 05/24/1983
• Est. Priority Date: 05/08/1979
• Status: Expired due to Term

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Kobayashi, Katsumi, Ito, Norio, Shioda, Takizo
• Primary Examiner(s): Martin, John C.
• Application Number:
  US06/321,763
• Time in Patent Office: 554 Days
• Field of Search: 358/54, 358/60, 358/127, 358/97, 358/180, 358/214-216, 358/237, 358/242, 315/395, 360/33
• US Class Current: 348/781
• CPC Class Codes: H04N 3/223 Controlling dimensions by maintaining the cathode-ray tube high voltage constant H04N3/185
• CPC Class Codes: H04N 5/7408 Direct viewing projectors, e.g. an image displayed on a video CRT or LCD display being projected on a screen

Abstract

An image display apparatus having a cathode ray tube with a deflection device, a projection screen and a projection lens projecting an image from the picture screen of the cathode ray tube onto the projection screen, is further provided with a deflection width control device which changes a dimension particularly the width of the cathode ray tube raster, in response to a change in the type of a television signal supplied to the tube.

Claims

1. An image display apparatus comprising:

a cathode ray tube including a picture screen and in which an electron beam modulated with television signals is directed against said screen, and deflection means by which said electron beam is made to scan said picture screen in a raster for forming an image on said picture screen;

a projection screen;

projection lens means for projecting said image from said picture screen of said cathode ray tube onto said projection screen; and

deflecting width control means for changing the horizontal width of said raster in accordance with a change in the type of said television signals, said deflecting width control means including first and second sources of relatively low and high horizontal deflecting voltages, respectively, means for detecting said changes in the type of television signals and producing as its output a control signal in response thereto, and horizontal selecting switch means for selectively connecting said first and second sources to said deflection means in response to said control signal.

2. An image display apparatus according to claim 1;

in which said television signals for modulating said beam in said cathode ray tube are recorded on a record medium which also bears a recorded signal identifying the type of said television signals; and

further comprising means for reproducing the television signals and the recorded signal identifying said type of the reproduced television signal, means for applying the reproduced television signals to said cathode ray tube, and means for applying the reproduced type-identifying signals to said means for detecting said change in the type of television signal.

3. An image display apparatus according to claim 1;

further comprising;

camera means having a target on which an image of an object in the field of view of said camera means is projected and being operative to provide said television signals in response to said image on the target, and including a deflection means having a vertical deflecting coil and a vertical deflecting circuit for determining a vertical dimension of a raster with which said target is scanned;

means for changing the effective aspect ratio of the television signals provided by said camera means, including sources of relatively high and low vertical deflecting voltages, vertical selecting switch means for selectively applying said high and low vertical deflecting voltages to said vertical deflecting circuit;

means for controlling said vertical selecting switch means simultaneously with said deflecting width control means; and

means for applying to said cathode ray tube said television signals provided by said camera means.

4. An image display apparatus according to claim 3;

in which said means for controlling said vertical selecting switch means and said horizontal selecting switch means include control switch means actuable to provide a control signal, and said vertical and horizontal selecting switch means are simultaneously responsive to said control signal.

5. An image display apparatus according to claim 3;

in which said means for applying to said cathode ray tube the television signals provided by said camera means includes means for recording said television signals from said camera means on a record medium and for reproducing said television signals from said record medium and applying the same to said cathode ray tube;

said means for controlling said vertical selecting switch means includes control switch means actuable to provide a control signal to said vertical selecting switch means for operating the latter and to said means for recording and for reproducing so as to be recorded on, and reproduced from said record medium along with the respective television signals; and

said means for controlling said horizontal selecting switch means includes detecting means for detecting the control signal reproduced from said record medium and for providing a corresponding control signal to said horizontal selecting switch means for operating the latter.

6. An image display apparatus comprising:

means for reproducing television signals recorded on a record medium along with a signal identifying the type of said television signals;

means for reproducing said signal identifying the type of said television signals;

a cathode ray tube including a picture screen and deflection means by which an electron beam is made to scan said picture screen in a raster for forming an image on said picture screen in response to supplying of the reproduced television signals to the cathode ray tube, said deflection means including a horizontal deflecting coil mounted on said cathode ray tube and a horizontal deflecting circuit;

a projection screen;

projection lens means for projecting said image from said picture screen of said cathode ray tube onto said projection screen; and

deflecting width control means connected with said horizontal deflecting circuit for determining the horizontal width of said raster so that the raster has limited dimensions in both the vertical and the horizontal directions when reproduced television signals of a standard type are supplied to said cathode ray tube, and the raster has a limited dimension only in the vertical direction when reproduced television signals of a special type are supplied, said deflecting width control means including sources of relatively low and high horizontal deflecting voltages, selecting switch means for selectively connecting said sources to said horizontal deflecting circuit in response to a control signals, and means for detecting said reproduced signal identifying said type of said television signals and providing said control signal in response thereto for controlling said selecting switch means.

7. An image display apparatus comprising:

camera means having a target on which an image of an object in the field of view of said camera is projected and being operative to provide television signals corresponding to said image in response to the scanning of said target by an electron beam, deflection means having a vertical deflecting coil and a vertical deflecting circuit for determining the vertical dimension of a raster with which said target is scanned by said beam, and means for changing the effective aspect ratio of said television signals including sources of relatively high and low vertical deflecting voltages and first selecting switch means for selectively applying said high and low vertical deflecting voltages to said vertical deflecting circuit for obtaining standard and special types, respectively, of television signals from said camera means;

a cathode ray tube including a picture screen and deflection means by which an electron beam is made to scan said picture screen in a raster for forming an image on said picture screen in response to said television signals supplied from said camera means, said deflection means including a horizontal deflecting coil mounted on said cathode ray tube and a horizontal deflecting circuit;

a projection screen;

projection lens means for projecting said image from said picture screen of said cathode ray tube onto said projection screen;

deflecting width control means connected with said horizontal deflecting circuit for changing the horizontal width of said raster when television signals of said special type are supplied to said cathode ray tube, said raster having limited dimension in the vertical and horizontal directions when said signals of standard type are supplied to said cathode ray tube, said raster having a limited dimension only in the vertical direction when television signals of said special type are so supplied, said deflecting width control means including sources of relatively low and high horizontal deflecting voltages, second selecting switch means for selectively applying said low and high horizontal deflecting voltages to said horizontal deflecting circuit, and means for controlling said second selecting switch means in accordance with the control of said first selecting switch means.

8. An image display apparatus according to claim 7;

in which said means for controlling said first selecting switch means and said second selecting switch means include control switch means actuable to provide a control signal, and said first and second selecting switch means are simultaneously responsive to said control signal.

9. An image display apparatus according to claim 7;

in which said means for applying to said cathode ray tube the television signals provided by said camera means includes means for recording said television signals from said camera means on a record medium and for reproducing said television signals from said record medium and applying the same to said cathode ray tube;

said means for controlling said first selecting switch means includes control switch means actuable to provide a control signal to said first selecting switch means for operating the latter and to said means for recording and for reproducing so as to be recorded on, and reproduced from said record medium along with the respective television signals; and

said means for controlling said second selecting switch means includes detecting means for detecting the control signal reproduced from said record medium and for providing a corresponding control signal to said second selecting switch means for operating the latter.

10. Image projection apparatus comprising:

video amplifier means having an input terminal selectively supplied with first and second modes of video signals having a standard aspect ratio and a non-standard aspect ratio, respectively;

a cathode ray tube including a picture screen of standard aspect ratio and in which an electron beam modulated with video signals from said amplifier means is directed against said screen;

deflection means for deflecting said electron beam so as to scan said picture screen in a raster for forming an image on said picture screen;

deflection width control means connected to said deflection means for selectively changing the horizontal deflection width of said electron beam in said cathode ray tube upon a change in the mode of said video signals supplied to said amplifier means, said control means having a first stage for said first mode of video signals providing a first raster of standard aspect ratio with a height and a width of said first raster being less than the height and width, respectively, of said picture screen, and said control means having a second state for said second mode of video signals providing a second raster of said non-standard aspect ratio with the height of said second raster being substantially the same as said height of the first raster and the width of said second raster being substantially the same as said width of the picture screen;

a projection screen having an aspect ratio which is substantially larger than said standard aspect ratio; and

projection lens means for projecting onto said projection screen said image formed on said picture screen, said projection lens means enlarging the projected image so that the height of the latter substantially corresponds to the height of said projection screen when video signals of said first mode are supplied to said amplifier means and said deflection width control means is in said first state, and so that the height and width of the projected image substantially correspond to the height and width, respectively, of said projection screen when video signals of said second mode are supplied and said deflection width control means is in said second state.