Color temperature adjusting device

• US 5,424,798 A
• Filed: 03/07/1994
• Issued: 06/13/1995
• Est. Priority Date: 11/12/1991
• Status: Expired due to Term

• Current Assignee: Nikon Corporation
• Original Assignee: Nikon Corporation
• Inventors: Takagi, Tadao
• Primary Examiner(s): Perkey, W. B.
• Application Number:
  US08/206,223
• Time in Patent Office: 463 Days
• Field of Search: 354/430, 354/413, 362/16, 362/18, 315/46, 315/50, 315/158, 315/241 P, 315/200 A
• US Class Current: 396/275
• CPC Class Codes: G01J 1/08 Arrangements of light sources specially adapted for photometry standard sources, also using luminescent or radioactive material
• CPC Class Codes: G01J 1/42 using electric radiation detectors optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10
• CPC Class Codes: G03B 15/03 Combinations of cameras with lighting apparatus; Flash units
• CPC Class Codes: G03B 19/12 Reflex cameras with single objective and a movable reflector or a partly-transmitting mirror
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control
• CPC Class Codes: H05B 45/20 Controlling the colour of the light

Abstract

A color temperature adjusting device for an auxiliary light source comprises a color temperature metering device for measuring a color temperature of an object field and a color temperature adjuster for adjusting a color temperature of the auxiliary light source in accordance with the color temperature measured by the color temperature metering device.

Claims

1. A color temperature adjusting device for an auxiliary light source, comprising:

color temperature metering means for measuring a color temperature of an object field; and

color temperature adjusting means for adjusting a color temperature of said auxiliary light source toward the color temperature measured by said color temperature metering means only when the color temperature measured by said color temperature metering means is lower than a predetermined temperature.

2. A color temperature adjusting device for an auxiliary light source, comprising:

a color temperature metering device which measures a color temperature of an object field; and

color temperature adjusting circuitry which adjusts a color temperature of said auxiliary light source toward the color temperature measured by said color temperature metering device, wherein said color temperature adjusting circuitry has a color temperature setting component for manual inputting of a desired color temperature by a user and adjusts the color temperature of said auxiliary light source toward the color temperature input by said color temperature setting component.

3. A color temperature adjusting device for an auxiliary light source, comprising:

a color temperature metering device which measures a color temperature of an object field; and

color temperature adjusting circuitry which adjusts a color temperature of said auxiliary light source toward the color temperature measured by said color temperature metering device, wherein said color temperature metering device and said color temperature adjusting circuitry are provided with said auxiliary light source in a unit attachable to and detachable from a camera.

4. A color temperature adjusting device for an auxiliary light source, comprising:

a color temperature metering device which measures a color temperature of an object field; and

color temperature adjusting circuitry which adjusts a color temperature of said auxiliary light source toward the color temperature measured by said color temperature metering device, wherein said color temperature adjusting circuitry adjusts the color temperature of said auxiliary light source by adjusting an inductance in a circuit of said auxiliary light source.

5. A color temperature adjusting device for an auxiliary light source, comprising:

a color temperature metering device which measures a color temperature of an object field; and

color temperature adjusting circuitry which adjusts a color temperature of said auxiliary light source toward the color temperature measured by said color temperature metering device, wherein said color temperature adjusting circuitry has a first adjustable-transmittance liquid crystal filter having a first hue and a second adjustable-transmittance liquid crystal filter having a second hue and adjusts the color temperature of said auxiliary light source by applying voltage to said first and second liquid crystal filters.

6. A device according to claim 5, wherein said first and second liquid crystal filters have a common optical axis.

7. A device according to claim 5, wherein said first and second liquid crystal filters are arranged in series in a path of light emitted by said auxiliary light source.

8. A color temperature adjusting device for an auxiliary light source, comprising:

a color temperature metering device which measures a color temperature of an object; and

color temperature adjusting circuitry which adjusts a color temperature of said auxiliary light source based on the color temperature measured by said color temperature metering device, wherein said color temperature adjusting circuitry includes an adjustable-transmittance liquid crystal filter having a hue and disposed in a path of said auxiliary light.