RETRACTABLE PHOTOGRAPHIC LENS

Abstract

A retractable photographic lens includes a moving ring; a holding frame which holds a retractable optical element and is movable between a photographing position and a displaced position displaced from the photographing position; and a driving device which moves the holding frame from the photographing position to the displaced position using a rearward moving force of the moving ring when the retractable photographic lens moves from a operating state to a fully-retracted state. The driving device includes first and second driving devices which give the holding frame first and second amounts of retractive movement per unit of movement of the moving ring, respectively. When the retractable photographic lens moves from the operating state to the fully-retracted state, the first driving device firstly moves the holding frame toward the displaced position and subsequently the second driving device moves the holding frame to the displaced position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described below in detail with reference to the accompanying drawings in which:

FIG. 1 is a front elevational view of an embodiment of a digital camera incorporating a retractable zoom lens according to the present invention;

FIG. 2 is a longitudinal sectional view of the digital camera shown in FIG. 1 in a ready-to-photograph state of the zoom lens thereof;

FIG. 3 is a longitudinal sectional view of the digital camera shown in FIG. 1 in the fully-retracted state of the zoom lens;

FIG. 4 is a perspective view of the zoom lens of the digital camera shown in FIG. 1 in the fully-retracted state of the zoom lens;

FIG. 5 is an exploded perspective view of a portion of the zoom lens shown in FIG. 4;

FIG. 6 is an exploded perspective view of another portion of the zoom lens shown in FIG. 4;

FIG. 7 is an enlarged perspective view of a portion of the elements shown in FIG. 5 in the vicinity of a stationary holder of the zoom lens;

FIG. 8 is a perspective view of the stationary holder;

FIG. 9 is an enlarged perspective view of a portion of the stationary holder which includes a lens-retracting/guiding projection that is formed integral with the stationary holder and projects forward therefrom;

FIG. 10 is a perspective view of the stationary holder and a second lens frame, showing the photographing position and the radially-retracted position of the second lens frame relative to the second lens frame;

FIG. 11 is a perspective view of the stationary holder and the second lens frame in a state where the second lens frame is retracted to the radially-retracted position, showing the positional relationship among the second lens frame, the stationary holder and the lens-retracting/guiding projection;

FIG. 12 is a front elevational view of the second lens frame, the stationary holder and the lens-retracting/guiding projection shown in FIG. 11 in a state where the second lens frame is retracted to the radially-retracted position;

FIG. 13 is an enlarged front elevational view of a portion of the elements shown in FIG. 12 in the vicinity of the second lens frame and the lens-retracting/guiding projection;

FIG. 14 is front perspective view of the second lens frame;

FIG. 15 is a rear perspective view of the second lens frame; and

FIG. 16 is an enlarged perspective view of another embodiment of the lens-retracting/guiding projection that is formed integral with the stationary holder and projects forward therefrom.

Claims

1. A retractable photographic lens comprising: an optical-axis-direction moving ring which moves rearward along an optical axis of a photographing optical system when said retractable photographic lens moves from an operating state to a fully-retracted state;a retractable-optical-element holding frame which holds a retractable optical element of said photographing optical system, said retractable-optical-element holding frame being positioned inside said optical-axis-direction moving ring and supported thereby to be movable between a photographing position at which said retractable optical element is aligned with said optical axis and a displaced position at which said retractable optical element is displaced from said photographing position; anda lens-element-retracting driving device which moves said retractable-optical-element holding frame from said photographing position to said displaced position using a rearward moving force of said optical-axis-direction moving ring when said retractable photographic lens moves from said operating state to said fully-retracted state,wherein said lens-element-retracting driving device includes a first lens-element-retracting driving device which gives said retractable-optical-element holding frame a first amount of retractive movement per unit of movement of said optical-axis-direction moving ring, and a second lens-element-retracting driving device which gives said retractable-optical-element holding frame a second amount of retractive movement per unit of movement of said optical-axis-direction moving ring, said second amount of retractive movement being smaller than said first amount of retractive movement, andwherein, when said retractable photographic lens moves from said operating state to said fully-retracted state, said first lens-element-retracting driving device firstly moves said retractable-optical-element holding frame toward said displaced position and subsequently said second lens-element-retracting driving device moves said retractable-optical-element holding frame to said displaced position.

2. The retractable photographic lens according to claim 1, further comprising: a rear-mounted member positioned behind said optical-axis-direction moving ring and said retractable-optical-element holding frame, a distance between said rear-mounted member and said optical-axis-direction moving ring in said optical axis direction becoming smaller as said retractable photographic lens moves from said operating state to said fully-retracted state,wherein said first lens-element-retracting driving device and said second lens-element-retracting driving device include a first rear-mounted engaging portion and a second rear-mounted engaging portion, respectively, which are provided on said rear-mounted member at different positions both in a direction parallel to said optical axis and in a direction orthogonal to said optical axis; and a first engaging portion and a second engaging portion, respectively, which are provided on said retractable-optical-element holding frame and come into contact with said first rear-mounted engaging portion and said second rear-mounted engaging portion, respectively, with a time difference therebetween when said optical-axis-direction moving ring moves rearward.

3. The retractable photographic lens according to claim 2, wherein said first rear-mounted engaging portion and said second rear-mounted engaging portion are formed on a projection which projects forward from said rear-mounted member in said optical axis direction.

4. The retractable photographic lens according to claim 2, wherein each of said first rear-mounted engaging portion and said second rear-mounted engaging portion comprises: a lens-retracting/guiding surface which is inclined to said optical axis, and gives said retractable-optical-element holding frame a moving force which moves said retractable-optical-element holding frame in a direction from said photographing position to said displaced position in accordance with a rearward movement of said optical-axis-direction moving ring; anda holding surface which is formed behind said lens-retracting/guiding surface in said optical axis direction to be continuous with said lens-retracting/guiding surface, said holding surface extending parallel to said optical axis, and preventing said retractable-optical-element holding frame from moving toward said photographing position from said displaced position via engagement with said retractable-optical-element holding frame.

5. The retractable photographic lens according to claim 4, wherein an angle of said lens-retracting/guiding surface of said first rear-mounted engaging portion relative to said optical axis is greater than an angle of said lens-retracting/guiding surface of said second rear-mounted engaging portion relative to said optical axis.

6. The retractable photographic lens according to claim 2, wherein said rear-mounted member is immovable in said optical axis direction.

7. The retractable photographic lens according to claim 1, wherein said retractable-optical-element holding frame is pivoted about a pivot on said optical-axis-direction moving ring to be swingable between said photographing position and said displaced position.

8. The retractable photographic lens according to claim 7, wherein said pivot extends substantially parallel to said optical axis.

9. The retractable photographic lens according to claim 7, wherein a radial distance from said first lens-element-retracting driving device to said pivot of said retractable-optical-element holding frame is different from a radial distance from said second lens-element-retracting driving device to said pivot of said retractable-optical-element holding frame.

10. The retractable photographic lens according to claim 7, wherein said first lens-element-retracting driving device and said second lens-element-retracting driving device comprises a first lens-retracting/guiding surface and a second lens-retracting/guiding surface which are inclined to said optical axis by mutually different angles, wherein the radial distance from said pivot to said first lens-retracting/guiding surface and the radial distance from said pivot to and second lens-retracting/guiding surface are mutually identical.

11. The retractable photographic lens according to claim 4, wherein said retractable-optical-element holding frame comprises: a cylindrical lens holder portion configured to hold said retractable optical element;a swing arm portion projecting from said cylindrical lens holder portion in a radial direction of said cylindrical lens holder portion; anda pivoted cylindrical portion located at an end of said swing arm portion and fitted on a pivot which extends substantially parallel to said optical axis and which is positioned inside said retractable-optical-element holding frame,wherein said swing arm portion includes a first retracted state holding surface and a second retracted state holding surface which are located in that order from said pivoted cylindrical portion side, and are engaged with said holding surface of said first rear-mounted engaging portion and said holding surface of said second rear-mounted engaging portion, respectively, to hold said retractable-optical-element holding frame in said displaced position when said retractable photographic lens moves from said operating state to said fully-retracted state.

12. The retractable photographic lens according to claim 1, wherein said retractable-optical-element holding frame is positioned inside said optical-axis-direction moving ring and supported thereby to be movable in a straight radial direction between said photographing position and said displaced position.

13. The retractable photographic lens according to claim 1, wherein said retractable-optical-element holding frame is movable in a plane substantially orthogonal to said optical axis between said photographing position and said displaced position relative to said optical-axis-direction moving ring.

14. The retractable photographic lens according to claim 1, wherein said retractable-optical-element holding frame is biased toward said photographing position by a spring, said first and second lens-element-retracting driving devices moving said retractable-optical-element holding frame from said photographing position to said displaced position against a biasing force of said spring.

15. The retractable photographic lens according to claim 2, wherein said optical-axis-direction moving ring is guided linearly along said optical axis without rotating relative to said rear-mounted member.

16. The retractable photographic lens according to claim 1, wherein said photographing optical system comprises a zoom lens system, said retractable optical element serving as a part of said zoom lens system.

17. A retractable photographic lens comprising: an optical-axis-direction moving ring which moves rearward along an optical axis of a photographing optical system when said retractable photographic lens moves from an operating state to a fully-retracted state;a retractable-optical-element holding frame which holds a retractable optical element of said photographing optical system and is positioned inside said optical-axis-direction moving ring and pivoted about a pivot thereon to be swingable between a photographing position at which said retractable optical element is aligned with said optical axis and a displaced position at which said retractable optical element is displaced from said photographing position; anda rotatable lens-element-retracting device which rotates said retractable-optical-element holding frame from said photographing position to said displaced position using a rearward moving force of said optical-axis-direction moving ring when said retractable photographic lens moves from said operating state to said fully-retracted state,wherein said rotatable lens-element-retracting device includes a first lens-element-retracting rotating device which gives said retractable-optical-element holding frame a first amount of retractive rotation per unit of movement of said optical-axis-direction moving ring in said optical axis direction; and a second lens-element-retracting rotating device which gives said retractable-optical-element holding frame a second amount of retractive rotation per unit of movement of said optical-axis-direction moving ring in said optical axis direction, said second amount of retractive rotation being smaller than said first amount of retractive rotation,wherein a radial distance from said first lens-element-retracting rotating device to said pivot of said retractable-optical-element holding frame is different from a radial distance from said second lens-element-retracting rotating device to said pivot of said retractable-optical-element holding frame, andwherein, when said retractable photographic lens moves from said operating state to said fully-retracted state, said first lens-element-retracting rotating device firstly rotates said retractable-optical-element holding frame toward said displaced position and subsequently said second lens-element-retracting rotating device rotates said retractable-optical-element holding frame to said displaced position.