Flasher capable of varying a light distribution angle

• US 5,854,949 A
• Filed: 10/18/1996
• Issued: 12/29/1998
• Est. Priority Date: 10/20/1995
• Status: Expired due to Term

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Furukawa, Akio, Nakahira, Toshiaki
• Primary Examiner(s): Lee, Eddie C.
• Assistant Examiner(s): Mahoney, Christopher E.
• Application Number:
  US08/732,710
• Time in Patent Office: 802 Days
• Field of Search: 396/795, 396/62, 396/175, 396/200, 362/16-18
• US Class Current: 396/200
• CPC Class Codes: G03B 15/05 Combinations of cameras with electronic flash apparatus; Electronic flash units
• CPC Class Codes: G03B 2215/0585 Movable reflectors, e.g. change of illumination angle or direction

Abstract

A stationary reflecting mirror (reflecting umbrella 2) is provided for reflecting light, emitted from a xenon discharge tube (3), to the side of an object to be photographed. An upper reflector plate (5) is provided above and in front of the stationary reflecting umbrella (2) and a lower reflector plate (6) is provided below and in front of the stationary reflecting umbrella (2). The upper and lower deflector plates (5, 6) are constructed so as to be pivoted in interlock with a change in the focal length of a photographic lens. With the upper and lower deflector plates (5, 6), part of light emitted from an opening (2A) is reflected and the direction of the reflected light that is emitted to the object is varied, and thereby the distribution angle of the light emitted to the object is varied. In this way, there is obtainable a flasher which is structurally simple and inexpensive without using high-performance lenses or an accurate moving mechanism.

Claims

1. A flasher comprising:

a reflecting assemblage which receives light emitted from a flash source and irradiates reflected light toward an object to be photographed wherein a distribution angle of the light that is irradiated toward said object is variable,

said reflecting assemblage comprising a stationary reflecting mirror where a distribution angle of the light reflected toward said object is constant, said stationary reflecting mirror having an upper portion, lower portion and depth portion with a reflecting surface positioned in the upper portion, lower portion and depth portion,

a movable reflecting mirror having an upper reflector plate disposed above said stationary mirror and a separate lower reflector plate disposed below said stationary mirror, each of said upper and lower reflector plates being separate from the stationary reflecting mirror, wherein said upper and lower reflector plates are interlocked and configured to rotate about an axis of said stationary mirror, where a distribution angle of the light reflected toward said object is variable, and

a drive mechanism for driving said movable reflecting mirror.

2. A flasher for use in a camera with a variable field angle of coverage, comprising:

a reflecting assemblage for receiving light emitted from a flash source and irradiating reflected light toward an object to be photographed wherein a distribution angle of the light that is irradiated toward said object is varied with a change in said field angle of coverage,

said reflecting assemblage comprising a stationary reflecting mirror where a distribution angle of the light reflected toward said object is constant, said stationary reflecting mirror having an upper portion, lower portion and depth portion with a reflecting surface positioned in the upper portion, lower portion and depth portion,

a movable reflecting mirror having an upper reflector plate disposed above said stationary mirror and a separate lower reflector plate disposed below said stationary mirror, each of said upper and lower reflector plates being separate from the stationary reflecting mirror, wherein the upper and lower reflector plates are interlocked and configured to rotate about an axis of said stationary mirror, where a distribution angle of the light reflected toward said object is variable, and

a drive mechanism for driving said movable reflecting mirror in interlock with a change in said field angle of coverage.

3. A flasher for use in a camera with varifocal photographic lenses comprising:

a reflecting assemblage for receiving light emitted from a flash source and irradiating reflected light toward an object to be photographed wherein a distribution angle of the light that is irradiated toward said object is varied with a change in focal length of said varifocal photographic lens,

said reflecting assemblage comprising a stationary reflecting mirror where a distribution angle of the light reflected toward said object is constant, said stationary reflecting mirror having an upper portion, lower portion and depth portion with a reflecting surface positioned in the upper portion, lower portion and depth portion,

a movable reflecting mirror having an upper reflector plate disposed above said stationary mirror and a separate lower reflector plate disposed below said stationary mirror, each of said upper and lower reflector plates being separate from the stationary reflecting mirror, wherein said upper and lower reflector plates are interlocked and configured to rotate about an axis of said stationary mirror, where a distribution angle of the light reflected toward said object is variable, and

a drive mechanism for driving said movable reflecting mirror in interlock with a change in said focal length.

4. The flasher as set forth in claim 3, wherein

said flash source is a cylindrically shaped flash discharge tube;

said stationary reflecting mirror is constructed so as to receive light emitted from said flash discharge tube and irradiate reflected light from an opening formed forwards toward said object to be photographed; and

the upper reflector plate being disposed in front of said opening, the lower reflector plate being disposed in front of said opening, and the upper and lower reflector plates receiving part of the light emitted from said opening and being titled up and down in interlock with a change in the focal length of said varifocal photographic lens so that a distribution angle of the reflected light emitted to said object is varied.

5. The flasher as set forth in claim 4, wherein said movable reflecting mirror is driven continuously or by steps in interlock with a change in said focal length.

6. The flasher as set forth in claim 4, wherein portions of said upper reflector plate and said lower reflector plate which are far away from said opening are supported, and when said focal length is on a wide-angle side, portions of said upper and lower reflector plates which are near said opening are driven so as to be moved away from each other, and when said focal length is on a telephoto side, said portions of said upper and lower reflector plates which are near said opening are driven so as to be moved toward each other.

7. The flasher as set forth in claim 6, wherein a reflecting surface of each of said upper reflector plate, said lower reflector plate, and said stationary reflecting mirror has a parabolic shape.

8. The flasher as set forth in claim 7, wherein, when said focal length is on the telephoto side, the reflecting surface of the upper reflector plate and the reflecting surface of the lower reflector plate are disposed so that the reflecting surfaces are substantially continuous to parabolic reflecting surfaces extended from a parabolic reflecting surface of the stationary reflecting mirror toward said opening.

9. A flasher for use in a camera with varifocal photographic lenses having a variable distribution angle of flashed light, the flasher comprising:

a flash discharge tube which has a cylindrical contour;

a stationary reflecting umbrella for reflecting light emitted from said flash discharge tube and emitting the reflected light from an opening formed forwards toward an object to be photographed, said stationary reflecting umbrella having an upper portion, lower portion and depth portion with a reflecting surface positioned in the upper portion, lower portion and depth portion; and

an upper reflector plate and a separate lower reflector plate, both the upper and lower reflector plates being separate from the stationary reflecting umbrella with the upper reflector plate being disposed above and in front of said opening, and the lower reflector plate being disposed below and in front of said opening, the upper and lower reflector plates receiving part of the light emitted from said opening and being interlocked and rotatable about an axis of the stationary reflecting umbrella with a change in focal length of said photographic lens so that a distribution angle of the reflected light emitted to said object is varied.

10. The flasher as set forth in claim 9, wherein, when the focal length of the photographic lens is on a wide-angle side, said upper and lower reflector plates are driven so that they are opened in directions going away from upper and lower edge portions of the opening of the stationary reflecting umbrella, and when said focal length of the photographic lens is on a telephoto side, said upper and lower reflector plates are driven so that they are closed in directions going toward the upper and lower edge portions of the opening of said stationary reflecting umbrella, and a distribution angle of the flashed light that is emitted toward said object can be varied continuously or by steps by said stationary reflecting umbrella, said upper reflector plate, and said lower reflector plate.

11. The flasher as set forth in claim 9, wherein the upper reflector plate and the lower reflector plate are pivotably supported by shaft support members so that quantities of movement of the upper reflector plate and the lower reflector plate, based on a change in the focal length of the photographic lens, become greater at a side of the opening of the stationary reflecting umbrella than at a side near the object to be photographed.

12. The flasher as set forth in claim 9, wherein the upper reflector plate and the lower reflector plate are constructed so that, when they draw nearest to the opening of said stationary reflecting umbrella, the respective reflecting surfaces are continuously connected to a reflecting surface positioned at the opening of said stationary reflecting umbrella.

13. The flasher as set forth in claim 9, wherein the shaft support members which are supported in parallel with respective long edge portions of the upper and lower reflector plates are formed integrally with bent portions formed in respective end portions of said upper and lower reflector plates.

14. A flasher for use in a camera with varifocal photographic lenses having a variable distribution angle of flashed light, the flasher comprising:

a flash discharge tube which has a cylindrical contour;

a stationary reflecting umbrella having an upper portion, lower portion and depth portion with a reflecting surface positioned in the upper portion, lower portion and depth portion, wherein said flash discharge tube is positioned in said depth portion thereof and which emits light emitted from said flash discharge tube from a rectangular opening toward an object to be photographed and also reflects the light emitted from said flash discharge tube to emit the reflected light from said rectangular opening toward said object, the rectangular opening being formed at a front of said stationary reflecting umbrella and having a long edge portion positioned in parallel with a longitudinal direction of said flash discharge tube;

an upper reflector plate and a separate lower reflector plate each of which is separate from the stationary reflecting umbrella and has a rectangular shape, a long edge portion of the upper reflector plate being disposed near a front upper edge portion of said opening, a long edge portion of the lower reflector plate being disposed near a front lower edge portion of said opening, the upper and lower reflector plates receiving part of the light emitted from said opening and being pivoted on a shaft in parallel with a long edge of said rectangular shape in opposite directions in interlock with a change in focal length of said photographic lens so that a direction of the reflected light emitted to said object is varied; and

a frame structure which has shaft support holes for rotatably supporting respective rotational axes of said upper and lower reflector plates and also has a wall portion to which a bottom portion of the stationary reflecting umbrella abuts and is fixed, said flash discharge tube and said stationary reflecting umbrella being fixed to said frame structure, and said upper and lower reflecting plates being pivotably supported by said frame structure.