Backlighting and color control arrangement for LCD type video camera viewfinder having multiple backlighting sources

• US 5,748,237 A
• Filed: 02/04/1997
• Issued: 05/05/1998
• Est. Priority Date: 12/20/1993
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ueda, Toshiaki, Ueno, Katsuhiko, Ono, Yoshihiro, Koyama, Toshio
• Primary Examiner(s): Faile, Andrew
• Assistant Examiner(s): Vu, Ngoc-Yen, VU, NGOC YEN T
• Application Number:
  US08/796,384
• Time in Patent Office: 455 Days
• Field of Search: 345/102, 345/109, 348/207, 348/223, 348/224, 348/227, 348/333, 348/334, 348/335, 396/373, 396/374, 396/385, 396/386, 349/67, 349/68, 362/8, 362/18, 362/29, 362/30
• US Class Current: 348/333.08
• CPC Class Codes: G02F 1/133618 for ambient light
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 5/66 Transforming electric information into light information scanning details H04N3/00

Abstract

A light condensing plate (13) is disposed on the side of a rear surface of an LCD (2). A light guiding plate (9) is disposed on the side of a rear surface of the light condensing plate (13). A back light (5) is disposed on the side of a rear surface of the light guiding plate (9). The light guiding plate (9) has a light diffusing surface (10) formed on its surface opposed to the light condensing plate (13) and a reflection surface (11) formed on its surface opposed to the back light (5). The light guiding plate (9) has a light condensing surface (12) formed on its upper end portion so as to be opposed to an external light admitting window (6) defined on a viewfinder barrel (1). A lid (8) for opening and closing the external light admitting window (6) is provided on the viewfinder barrel. (1)

Claims

1. A video camera comprising:

a lens for condensing light from an object;

an image sensor for converting light from said lens into an electric signal;

a signal processing circuit for converting the electric signal output from said image sensor into a predetermined video signal;

a liquid crystal display unit for displaying the video signal output from said signal processing unit;

first and second backlighting means for applying light to a rear surface of said liquid crystal display unit and for illuminating an image produced by said liquid crystal display unit in response to the video signal, said first backlighting means including a selectively energizable backlight which is pivotally mounted and which has a reflection surface formed on a front surface thereof, said backlight being movable between;

(a) an inclined position wherein the backlight is de-energized and is oriented with respect to said second backlighting means in a manner that light from said second backlighting means is reflected off the reflection surface against the rear surface of said liquid crystal display, and

(b) an upright position wherein the backlight is energized, and oriented with respect to said second backlighting means in a manner that light from said second backlighting means is blocked, and light from the selectively energizable backlight is directed against the rear surface of said liquid crystal display;

detecting circuit means for detecting external light intensity;

means for adjusting the video signal in white light balance to compensate for a difference in color temperature between light from said first backlighting means and light from said second backlighting means; and

controlling means for controlling the position of said first backlighting means on the basis of detections by said detecting circuit.

2. A video camera according to claim 1, further comprising diaphragm means for adjusting an amount of said light transmitted between said lens and said image sensor and wherein said detecting means also detects a state of said diaphragm means.

3. A video camera according to claim 1, wherein said detecting means detects a state of said white balance adjusting means.

4. A video camera according to claim 1, further comprising diaphragm means for adjusting an amount of light transmitted between said lens and said image sensor;

and wherein said detecting means also detects operative states of said diaphragm means and said white balance adjusting means.

5. A video camera according to claim 1, wherein said first backlighting means comprises a source of artificial light and said second backlighting means comprises a source of natural light.

6. A video camera according to claim 5, wherein said second backlighting means includes a light guiding plate which guides natural light toward said liquid crystal display.

7. A video camera according to claim 6, wherein a light diffusing plate is provided on one side surface of said light guiding plate.

8. A video camera according to claim 7, wherein at least one of said first and second backlighting means is movably mounted and selectively movable so as not to block an applied light.

9. A video camera according to claim 8, further comprising diaphragm means for adjusting an amount of said light transmitted to said image sensor and wherein said detecting circuit also detects a light adjusting state of said diaphragm means.

10. A video camera according to claim 9, wherein said detecting circuit also detects an operative state of said adjusting means.

11. A video camera according to claim 1, further comprising diaphragm means for adjusting a transmission amount of light to said image sensor, said detecting means also detecting operative states of said diaphragm means and said white balance means.

12. A video camera according to claim 11, wherein said first backlighting means comprises a source of artificial light and said second backlighting means comprises a source of ambient light.

13. A video camera according to claim 12, wherein said second backlighting means includes a light guiding plate.

14. A video camera according to claim 13, further comprising a diffusing plate for diffusing a light said diffusing plate being provided on one surface of said light guiding plate.

15. A video camera according to claim 1, wherein light from the backlight is directed against the rear surface of said liquid crystal display after being transmitted through the reflection surface.

16. A video camera according to claim 1, wherein the backlight is rotated as it moved from said inclined position to said upright position so that the reflection surface is positioned on the opposite side of the backlight with respect to said liquid crystal display so that light from said second backlighting means is reflected and blocked by the reflection surface.