JP2002328412A - Illuminator having variable illuminating angle and photographing device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable illuminating angle illuminator which is extremely small, thin, and lightweight, and in particular to greatly and efficiently change the state of light condensation and diffusion in the longitudinal direction of the light source. SOLUTION: The illuminator is provided with a light source, a first optical member 6 which has a light condensing function in the longitudinal direction of the light source, and a pair of second optical members 7 and 7' which can be moved in the longitudinal direction and the opposite direction of the light source. The first optical member consists of a plurality of prism members which have a air layer being oblique relative to the longitudinal direction of the light source.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device having a variable irradiation angle and a photographing device using the same. For example, the lighting device is mounted on a part of a camera body (photographing device) and linked with a photographing operation of the camera body. It is suitable for use in optical devices such as video cameras, film cameras, digital cameras, etc., which change the irradiation angle of the illumination light (flash light) according to the purpose and efficiently irradiate the object side for photographing.

[0002]

2. Description of the Related Art With respect to an illumination device used for a photographing device such as a camera, various devices have been conventionally used in order to efficiently converge a light beam emitted in various directions from a light source within a required irradiation angle of view. The proposal has been made. Especially in recent years, instead of the Fresnel lens surface placed in front of the light source,
There has been proposed one in which an optical member using total reflection such as a prism or a light guide is arranged to improve the light collection efficiency and reduce the size.

[0003] On the other hand, although the photographing apparatus tends to have a high magnification zoom, if an illuminating device having a fixed irradiation range is used for such a photographing apparatus, the illumination of the maximum irradiation range can be performed even in a telephoto state where the required irradiation range is narrow. Energy loss increases. In order to solve this phenomenon, an illumination device with a variable illumination angle that performs illumination corresponding to a photographing range has been conventionally proposed.

As a well-known technique of an illumination system to which the above two techniques are applied, Japanese Patent Laid-Open No. 4-138439 discloses a positional relationship between an optical prism and a light source with respect to a condensing optical system that performs total reflection by an optical prism. Is changed relatively to change the irradiation range by switching between the total reflection surface and the refraction. In Japanese Patent Application Laid-Open No. 8-262538, the optical prism is divided into a plurality of parts, and the optical prisms arranged vertically are rotated to switch the irradiation range.

Further, regarding the variable irradiation angle in the longitudinal direction of the light source, the light path is switched by inserting or rotating a diffusion member or a reflection member in synchronization with the front-back movement of the front panel in the direction along the emission optical axis. In addition, there is one in which the optical path is changed by a prism formed integrally with the front panel.

[0006]

By arranging an optical member utilizing total internal reflection such as a prism or a light guide in front of the light emitting means, it is possible to improve the light collection efficiency, reduce the size, and change the irradiation angle. As a proposal of an illuminating device, as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 4-138439, a luminous flux mainly emitted to the side of a light source is made incident on an optical member on a front surface of a flash light emitting device, and is then totally reflected to be fixed in a certain direction. It is composed of two upper and lower surfaces that converge light and a surface that has a positive refractive power formed separately from the front and condenses light. In some light condensing optical systems, the positional relationship between the optical prism and the light source is changed relatively to change the irradiation range by switching between reflection and transmission on the total reflection surface.

On the other hand, Japanese Patent Application Laid-Open No. 8-262538 proposes a device in which an optical prism is divided into a plurality of parts, and the optical prisms arranged above and below are rotated to switch the irradiation range.

However, none of the proposals is directed to the light converging and diffusing in the lateral direction (vertical direction) of the light source, and does not refer to the light converging and diffusing in the longitudinal direction of the light source.

In addition, in synchronization with longitudinal movement along the direction of the emission optical axis of the front panel for the purpose of condensing and diffusing light in the longitudinal direction (horizontal direction) of the light source, insertion and rotation of a diffusing member and a reflecting member are performed. , Such as switching the optical path, changing the optical path by a prism formed integrally with the front panel, etc., basically by moving the front panel back and forth in the direction along the emission optical axis of the optical member. There is a disadvantage that the shape is inevitably increased in size because the light is condensed and diffused in the vertical direction. Further, in the above three methods, since the light condensing and diffusing action in the horizontal direction is constituted only by a certain portion with respect to the entire area of the exit surface, it is difficult to largely vary the irradiation angle.

From the above, it can be seen that the present invention makes it possible to perform irradiation efficiently by changing the shape of the condensing diffusion in the horizontal direction drastically and by taking a shape that functions efficiently according to each state of the condensing diffusion. An object of the present invention is to provide a lighting device having a variable angle and a photographing device using the lighting device.

[0011] Further, a construction is adopted in which no evacuation space is required for the movement of the optical member in accordance with the change of the irradiation angle, the overall shape of the illumination optical system is extremely reduced in size, and further, the converging and diffusing region is continuously changed. Accordingly, it is an object of the present invention to provide an illumination device with a variable irradiation angle that can continuously change the light distribution characteristics at each zoom point, and an imaging device using the same.

In addition to the above, the present invention is extremely simple, inexpensive, and can achieve extremely small size, thinness, and light weight, and use the energy from the light source with high efficiency to obtain uniform light distribution characteristics at each zoom point. It is an object of the present invention to provide a lighting device having a variable irradiation angle suitable for optical devices such as a still camera, a video camera, and a digital camera having a simple configuration, and a photographing device using the same.

[0013]

According to a first aspect of the present invention, there is provided an illumination device with a variable illumination angle, which converts a light beam from a light source device into a predetermined illumination angle via an optical device and emits the light. The apparatus is characterized in that the light source means has a horizontally long tubular light emitter, and the optical means has an optical member located on the object side of the light source means and movable in the horizontal direction.

According to a second aspect of the present invention, in the illumination device of the first aspect, the optical unit has a first optical member and a second optical member in order from the light source unit toward the subject. The first optical member is formed with a refracting power in the horizontal direction, and the second optical member is disposed in a pair symmetrically in the horizontal direction with respect to the emission optical axis of the light source means. The member is characterized in that it is movable symmetrically with respect to the emission optical axis in the horizontal direction.

According to a third aspect of the present invention, in the illumination device of the first aspect, the optical unit includes a first optical member and a second optical member in order from the light source unit toward the subject. The first optical member is a trapezoidal prism member having an inclined surface such that a space in a horizontal cross section between the light source means and the first optical member expands toward both peripheral portions in the horizontal direction. The second optical member is arranged in a pair in the horizontal direction symmetrically with respect to the emission optical axis of the light source means, and the second optical member moves symmetrically in the horizontal direction with respect to the emission optical axis. It is characterized by being possible.

According to a fourth aspect of the present invention, in the illumination device of the first aspect, the optical means has a first optical member and a third optical member, and the first optical member is provided with the first optical member. A trapezoidal prism member having an inclined surface such that a space in a horizontal cross section between the light source means and the first optical member expands toward both peripheral portions in the horizontal direction, and the third optical member is horizontal. The third optical member is located at both horizontal peripheral portions of the first optical member, and has the longest slope of the triangle and the first optical member. It is characterized by having an air layer between the inclined surface and the facing surface.

According to a fifth aspect of the present invention, in the illumination device of the first aspect, the optical means includes a first optical member, a second optical member, a third optical member, and a fourth optical member. A first optical member including the light source means and the first optical member.
And a trapezoidal prism member having an inclined surface so that a space in a horizontal cross section between the optical member and the second optical member expands toward both peripheral portions in the horizontal direction, and the second optical member is the first optical member. And a third optical member symmetrically formed with respect to the emission optical axis of the light source means so as to be movable in the horizontal direction, and the third optical member is provided at both ends of the light source means in the horizontal direction. , Two prisms each having a triangular horizontal cross section symmetrically with respect to an optical axis of light emitted from the luminous body, the longest slope of the triangle, and the first optical member, And the fourth optical member is configured to face the third optical member.
The optical member is characterized in that it is a pair of reflectors that face each other on both outer surfaces in the horizontal direction and are symmetrically arranged with respect to the emission optical axis.

According to a sixth aspect of the present invention, in the illuminating device according to any one of the second to third aspects, the peripheral portion in the horizontal direction on the exit surface of the movable second optical member is provided. The Fresnel lens surface is formed in the area of
It is characterized in that a prism row is formed in a region at the center in the horizontal direction.

According to a seventh aspect of the present invention, in the illumination device of the sixth aspect, the Fresnel lens surface and the prism array provided on the movable second optical member are arranged with respect to a horizontal section. It is characterized by having a refractive power.

According to an eighth aspect of the present invention, in the illumination device of the first aspect, the movable optical member comprises a plurality of members which move in a horizontal direction, and the movable optical member has a symmetrical movement with respect to the emission optical axis. It is characterized by doing.

According to a ninth aspect of the present invention, in the illumination device of the second, third or fifth aspect, the movable surface of the movable second optical member has a total length of the first optical member. It is characterized in that the length is approximately half the length of the exit surface of the member.

According to a tenth aspect of the present invention, in the illuminating device with a variable irradiation angle according to any one of the first to fifth aspects, a reflector is provided behind the optical axis of the illuminant of the light source means to reflect a light beam emitted from the light source. In addition, the shape of the reflecting umbrella at least partially forms a reflecting surface concentric with the center of the light source.

According to the eleventh aspect of the present invention, there is provided an illumination apparatus with a variable illumination angle, which converts a light beam from a light source means into a predetermined illumination angle through an optical means and emits the light. Has a horizontally long tubular light emitter,
The optical means has a first optical member and a second optical member in this order from the light source means to the subject side, and the first optical member is arranged with the short side facing the light source means. The second optical member has a trapezoidal shape in a horizontal cross section, and the second optical member is arranged to face the subject side of the first optical member, and is formed as a pair symmetrically with respect to the emission optical axis so as to be movable in the horizontal direction. It is characterized by being.

According to a twelfth aspect of the present invention, in the illumination device of the eleventh aspect, the cylindrical lens surface has a refracting power in the horizontal direction at the horizontal center of the exit surface of the first optical member. So that it is formed vertically long,
It is characterized in that the Fresnel lens surface is formed vertically long so as to have a refracting power in the horizontal direction at a peripheral portion in the horizontal direction of the cylindrical lens surface.

According to a thirteenth aspect of the present invention, in the illumination device of the eleventh aspect, the second optical member has a vertical surface extending from the exit surface of the second optical member so that the Fresnel lens surface has a refractive power in the horizontal direction. It is characterized by being formed.

A illuminating device with a variable illumination angle according to a fourteenth aspect of the present invention is the illumination device with a variable illumination angle which converts a light beam from a light source means into a predetermined illumination angle via an optical means and irradiates the light beam. Has a horizontally long tubular light emitter,
The optical means has a first optical member and a second optical member in this order from the light source means to the subject side, and the first optical member is arranged with the short side facing the light source means. It has a trapezoidal shape in a horizontal section, and the second optical member is arranged so as to face the emission surface of the first optical member and is provided so as to be movable in the horizontal direction.

According to a fifteenth aspect of the present invention, in the illumination device according to the fourteenth aspect, the cylindrical lens surface has a refracting power in the horizontal direction at the horizontal center of the exit surface of the first optical member. So that it is formed vertically long,
It is characterized in that the Fresnel lens surface is formed vertically long so as to have a refracting power in the horizontal direction at a peripheral portion in the horizontal direction of the cylindrical lens surface.

According to a sixteenth aspect of the present invention, in the illumination device of the fourteenth aspect, the Fresnel lens surface has a refractive power in the horizontal direction at both peripheral portions in the horizontal direction of the exit surface of the second optical member. It is characterized by being formed vertically long so as to have.

The seventeenth aspect of the present invention relates to claims 1 to 5, 1
15. The illumination device according to any one of items 0, 11, and 14, wherein the light source is a straight tubular flash discharge tube.

The illumination device with a variable illumination angle according to the invention of claim 18 is a variable illumination angle illumination device for converting a light beam from a light source means into a predetermined illumination angle via an optical means and irradiating the light. Is located on the subject side with respect to the light source means, is movable from a position facing the front of the light source means to a position of a peripheral part in the horizontal direction of the optical means, and a plurality of light emitting surfaces are provided on an emission surface of the optical means. It is characterized in that a prism array is formed.

According to a nineteenth aspect of the present invention, in the illumination device with a variable illumination angle according to any one of the first to eighteenth aspects, the illumination device with a variable illumination angle changes the illumination angle in the vertical and horizontal directions. I have.

According to a twentieth aspect of the present invention, there is provided a photographing apparatus comprising:
20. An illumination device having a variable irradiation angle according to any one of items 1 to 19.

[0033]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described.

(First Embodiment) FIGS. 1 to 6 show a lighting device (hereinafter referred to as a flash light emitting device) with a variable irradiation angle according to a first embodiment of the present invention.

FIG. 1 is an external perspective view of a camera including a partial cross-sectional view of a flash light emitting device to which the present invention is applied, FIG. 2 is a perspective view of a main part of only the main optical system of the flash light emitting device in FIG.
FIG. 4 is a horizontal sectional view of the optical system of the flash light emitting device, and FIGS. 5 and 6 are vertical sectional views of the optical system of the flash light emitting device. 3 to 6 also show the ray trace diagrams of the representative light rays emitted from the light source.

The flash light emitting device shown in FIG. 1 is arranged at the upper right part of the camera body, and is configured to protrude above the camera when the camera is used.

In FIG. 1, 1 is a flash light emitting device, 11 is a photographing device main body, 12 is a lens barrel, and has a photographing lens. Reference numeral 13 denotes a release button, and reference numeral 14 denotes an operation member for zooming the photographing lens. The operation member can be zoomed in the telephoto direction by tilting the operation member forward, and can be zoomed in the wide direction by tilting the operation member rearward. 15 is an operation button for switching various modes of the camera, 16 is a liquid crystal display window for notifying the user of the operation of the camera, 17 is a viewing window of a photometric device for measuring the brightness of external light, and 18 is a viewing window of a finder. It is a window.

The functions except for the flash light emitting device 1 are well-known technologies, and a detailed description thereof will be omitted. Note that the mechanical components of the present invention are not limited to the above-described configuration.

In FIG. 2, reference numeral 2 denotes a straight-tube (cylindrical) flash discharge tube (xenon tube) having a horizontally long luminous body and emitting flash.

Reference numeral 3 denotes a reflector that reflects, in the light emitting direction (subject side), a light beam that travels backward in the light emitting direction (subject side) among the light beams emitted from the flash discharge tube 2, and has an inner surface having a high reflectance surface. It is made of a metal material such as formed bright aluminum, or a resin material having a high-reflectance metal-deposited surface formed on the inner surface.

Reference numerals 4 and 4 'denote fourth optical members disposed near both sides of the flash discharge tube 2, and are constituted by two reflectors.

Reference numerals 5 and 5 'denote third optical members.
Are positioned on the subject side, facing both ends of the flash discharge tube 2 in the horizontal direction, and the optical axis of the light emitted from the flash discharge tube 2 (the center line of the emitted light emitted from the light source means; It is composed of two third optical members (prisms) having a pair of horizontal triangular shapes symmetrically with respect to the optical axis). In addition, the outer surface of the triangle and the reflecting surface of the fourth optical member, which are arranged in a pair in the horizontal direction symmetrically with respect to the emission optical axis, face each other.

Reference numeral 6 denotes a plurality of cylindrical lens surfaces 6 having a positive refracting power in the vertical direction in a substantially half area corresponding to the vicinity of the center of the emission surface, which is located on the subject side of the flash discharge tube 2.
It is a first optical member (prism) on which c is formed. The first optical member 6 is formed of a trapezoidal prism member having an inclined surface in which a space in a horizontal section between the flash discharge tube 2 and the first optical member 6 expands toward both peripheral portions in the horizontal direction. Has become. The inclined surface is configured to face the third optical member with an air layer between the third optical member and the longest inclined surface of the triangle.

Reference numerals 7 and 7 'denote second optical members which are located on the object side of the first optical member (prism) 6 and are symmetrically arranged with respect to the emission optical axis of the light source means. is there. A plurality of cylindrical lens surfaces 7c having a negative refractive power in the vertical direction to cancel the refractive power of the cylindrical lens surface 6c of the first optical member (prism) 6 on the incident surfaces of the second optical members 7 and 7 '(see FIG. 5) is formed in a substantially half region near the center in the horizontal direction, and the other surfaces are flat surfaces 7b and 7b '.
Is formed.

Further, a plurality of vertically long prism rows 7d, 7d 'having a horizontal refracting power near the center in the horizontal direction of the exit surfaces of the second optical members 7, 7', and the horizontal surfaces of the exit surfaces Vertically long Fresnel lens surfaces 7a and 7a 'having a refractive power in the horizontal direction are formed in the peripheral portion in the direction.

The third optical members (prisms) 5, 5 '
And the first optical member (prism) 6 are disposed so as to face each other so that an air layer oblique to the longitudinal direction of the flash discharge tube 2 exists, and the second optical members 7 and 7 are arranged. ´
With respect to the exit surface of the first optical member (prism) 6
They are arranged at regular intervals and are configured to be movable in the horizontal direction. The total length of the exit surface of the second optical member is substantially half the length of the exit surface of the first optical member 6 (the total length of the exit surfaces of the second optical members 7 and 7 ′). Is ± 10% of the length of the exit surface of the first optical member 6.
And).

In the above configuration, the flash discharge tube 2, the reflector 3, the fourth optical members (reflectors) 4, 4 ', the third optical members (prisms) 5, 5', and the first optical members (prisms) 6) is integrated with a holding case or the like (not shown) to form a light emitting unit;
By appropriately moving the second optical members 7, 7 'to a predetermined optical arrangement position, it is possible to continuously change the degree of light collection. Further, the second optical member may be composed of a plurality of members.

The third optical members (prisms) 5, 5
As the material of the first optical member (prism) 6 and the second optical members 7 and 7 ', an optical resin material having a high transmittance such as an acrylic resin or a glass material is suitable.

In the above configuration, when the photographing device 11 is set to, for example, the "strobe auto mode", after the release button 13 is pressed by the user, the amount of external light measured by a photometric device (not shown) is measured. A central processing unit (not shown) determines whether or not the flash light emitting device 1 emits light based on the brightness and the sensitivity of the loaded film. When the central processing unit determines that the flash light emitting device 1 emits light in the photographing situation, the central processing unit outputs a light emission signal, and the flash discharge tube 2 is connected via a trigger lead wire attached to the reflector 3. To emit light.

A light beam emitted to the rear of the light-emitting body center axis of the flash discharge tube 2 (in a direction opposite to the object side) is returned to the light source via the reflector 3 and then irradiated to the object side. The light beam emitted in the direction (subject side) enters from the third optical member (prism) 5, 5 'or the first optical member (prism) 6 disposed on the front surface, and is incident on the fourth optical member (reflection plate). ) After being converted into predetermined light distribution characteristics via 4, 4 ', second optical members 7, 7', etc., the light is irradiated on the subject side.

The change in the light distribution characteristic is performed by moving the second optical members 7, 7 'in the horizontal direction.

According to the present invention, particularly when the photographing lens of the photographing device 11 is a zoom lens, the amount of movement of the second optical members 7 and 7 'in the horizontal direction is appropriately adjusted according to the focal length. This is a proposal of an illuminating device in which the light distribution characteristics in the vertical and horizontal directions are simultaneously made to correspond to the photographing range of the photographing lens. Hereinafter, the method for setting the optimum shape will be described in more detail with reference to FIGS.

FIG. 5 and FIG. 6 are vertical sectional views of the flash light emitting device 1 and show the basic concept of changing the irradiation angle in the vertical direction. 5 (a) and 5 (b) correspond to FIG.
6A corresponds to the AA section and the BB section, and FIGS. 6A and 6B correspond to the CC section and the DD section in FIG. 4A, respectively. In addition, the numbers of the respective parts in the drawings correspond to FIGS. 2 to 4.

As can be seen from FIGS. 2, 5 and 6, a plurality of cylindrical lens surfaces 6c having a positive refractive power in the vertical direction formed on the exit surface of the first optical member (prism) 6 are formed. Is formed only in a substantially half area corresponding to the vicinity of the center in the horizontal direction of the exit surface of the first optical member (prism) 6, and the periphery of the exit surface of the first optical member (prism) 6 in the horizontal direction is formed. The part is formed by planes 6b, 6b '.

First, referring to FIGS. 3 and 4, the state of converging and diffusing the emitted light in the horizontal direction will be described. FIG.
FIG. 4 is a diagram showing the most condensed state of the present invention, and second optical members 7 and 7 ′ which are operation members for performing irradiation angle variation.
Indicates a state in which it is arranged close to the vicinity of the center in the horizontal direction. In this state, the light ray tracing diagrams of FIGS. 3A to 3D show typical light emission points P,
Q, R, and S indicate the luminous flux emitted from the light source, and it is possible to estimate a certain irradiation angle range from the condensing state of the light.

As shown in FIG. 3A, the light beam emitted from the outermost point P enters from the entrance surface 5a of the third optical member (prism) 5, is totally reflected by the reflection surface 5b, and is exited. 5c
From the optical member, reflected by the fourth optical member (reflecting plate) 4, passed through the first optical member (prism) 6, and reached point P. The irradiation angle range is extremely narrow, and the directivity is small. It has a high luminous flux.

Further, as shown in FIG. 3B, the light beam emitted from the point Q enters from the entrance surface 5a of the third optical member (prism) 5, is totally reflected by the reflection surface 5b, and further exits. The light is totally reflected by the surface 5c, passes through the first optical member (prism) 6, and reaches the point Q. Like the light beam emitted from the point P in FIG. The luminous flux has high directivity.

As shown in FIG. 3 (c), the light beam emitted from the point R enters from the entrance surface 5a of the third optical member (prism) 5, is refracted by the reflection surface 5b, and is refracted by the first optical member (prism). After passing through the optical member (prism) 6, the light beam is refracted by the Fresnel lens surface 7a formed on the exit surface of the second optical member 7, and the irradiation range becomes a light beam narrowed to a certain angle range. ing.

As shown in FIG. 3D, the light flux near the central portion, which is shortest from the light source and most difficult to converge, is formed near the horizontal central portion of the second optical member 7. A prism array 7d (in this embodiment, the apex angle is constant at 105 °) is formed to have a converging function. As shown in the drawing, in the region where the point S exists, there is a light beam that reaches over a wide range from the light source, but the light beam emitted from the second optical member 7 has a uniform light angle within a certain range. Can be transformed into a distribution.

Next, a state where the irradiation angle range in the horizontal direction is the widest, that is, a state where light is diffused the most will be described with reference to FIG. The state shown here is a state in which the second optical members 7 and 7 ′, which are operation members for performing irradiation angle variation, have been moved to the farthest positions corresponding to both ends of the first optical member (prism) 6. It is. Here, FIGS. 4 (a) to 4 (d)
3 are observed under the same conditions as in FIGS. 3 (a) to 3 (d) in order to observe the correspondence with the change of the light flux in FIG. Trace with
Only the change in the light emission direction after that is shown. As shown in the figure, it can be seen that the light flux at each point is diffused, and the emission angle distribution changes greatly. Hereinafter, the situation of each point will be described in more detail.

At point P shown in FIG. 4 (a), significant refraction or total reflection occurs due to the Fresnel lens surface 7a of the second optical member 7, and significant angle conversion is performed in the direction of the exit optical axis. For this reason, there is no light beam traveling in the direction along the emission optical axis, and the light beam is converted into a light beam almost out of the required angle of view range.

Next, at the point Q shown in FIG. 4B, the light is refracted by the prism array 7d of the second optical member 7 and is converted in the direction along the emission optical axis. This light beam is generated by
The change in the angle is not so large as the light flux shown in FIG. In addition, the state where the prism row 7d, 7d 'hits the surface on the side refracted in the direction along the emission optical axis at point Q is shown.
Even when the light is refracted by the paired surfaces of the prism rows 7d and 7d ', the refraction converts the angle to a direction away from the direction along the emission optical axis to some extent, but converts it into a light flux within the required angle of view range. It is used effectively.

Next, at the point R shown in FIG. 4C, the characteristics of the second optical member 7 greatly change depending on the position of incidence on the prism array 7d. That is, as shown by the point R in the drawing, on the surface refracted in the direction along the exit optical axis of the prism array 7d, the irradiation direction is slightly outward and is hardly affected. On the other hand, when the light is refracted by a surface that is a pair with the prism, total reflection occurs on the prism surface as shown by R ′ in FIG.

Therefore, as in the case of FIG. 4A, there is an effect that the light beam traveling in the direction along the emission optical axis is partially reduced, and the irradiation angle range is relatively widened.

Finally, at point S shown in FIG.
With the movement of the optical member 7, the second optical member 7 does not exist at this position, the convergence effect of each optical member is not obtained, and the light distribution becomes uniform and wide.

As shown in each state of FIG. 4, the amount of luminous flux traveling in the direction along the emission optical axis is surely reduced, and the amount of divergent and divergent luminous flux is increased. It can be understood that the light distribution can be converted to a light distribution having the following.

Next, the variable irradiation angle in the vertical direction, which is changed in synchronization with the change in the irradiation range in the horizontal direction shown in FIGS. 3 and 4, will be described with reference to FIGS.

In the drawing, the inner and outer diameters of a glass tube as the flash discharge tube 2 are shown. As the actual light emission phenomenon of the flash discharge tube 2 of this type of flash light emitting device 1, in order to improve the efficiency, it is often the case that the light is emitted to the full inner diameter in order to improve the efficiency. You can think that you are doing. However, for ease of explanation, a light beam emitted from the center of the light source is considered as a representative light beam, and only the light beam emitted from the center of the light source is shown in the figure. As an actual light distribution characteristic, in addition to the representative light flux as shown in the figure, the light distribution characteristic changes in a slightly wider direction as a whole due to the light flux emitted from the peripheral portion in the longitudinal direction of the flash discharge tube 2. Since the tendency of the optical characteristics is almost the same, the following description will be made according to the representative light flux.

First, the characteristic shape of the optical system of the flash light emitting device 1 having the above configuration will be described in order. The reflector 3 has a semi-cylindrical shape that is substantially concentric with the flash discharge tube 2 in a shape behind the central axis of the light source (in a direction opposite to the subject side). This is an effective shape for returning the reflected light from the reflector 3 to the vicinity of the center of the light source again, and has an effect of making it less likely to be adversely affected by the refraction of the glass of the flash discharge tube 2. Further, with such a configuration, the reflected light from the reflector 3 can be treated as the emitted light substantially equivalent to the direct light from the light source, so that it is easy to think, and the overall shape of the optical system that follows can be reduced in size. convenient. The reason why the shape is just a semi-cylindrical shape is that if it is smaller than this, the third optical members (prisms) 5 and 5 'and the first optical member (prism) 6 are large in order to collect side light. On the contrary, if it is larger than this, the amount of luminous flux trapped inside the reflecting umbrella 3 is increased, and the efficiency is lowered.

The upper and lower (vertical) peripheral portions of the reflector 3 are formed so as to wrap around the third optical members 5, 5 'and the rear (reflection surfaces 5d, 6d) of the first optical member 6. However, this is for the following reasons.

That is, the light beam emitted from the center of the light source can be ideally reflected by the reflecting surfaces 5d and 6d on the back surface as shown in the figure. This is because, especially when the inner diameter of the light source is large, there is a light beam which cannot be totally reflected and is emitted from the reflection surfaces 5d and 6d, and such a light beam is used effectively.

That is, as shown in the figure, the form of the reflector 3 is extended to the third optical members (prisms) 5, 5 ′ and the back surfaces (reflection surfaces 5 d, 6 d) of the first optical member (prism) 6. Further, by following the shapes of the reflecting surfaces 5d and 6d, the light beams emitted from the reflecting surfaces 5d and 6d can be re-entered once without being totally reflected, and the reflected light beams can be efficiently applied to a predetermined irradiation range. This is because light can be condensed well.

The third optical members (prisms) 5, 5
', The first optical member (prism) 6 is set to have the following shape in the first embodiment.

First, a light beam traveling in the direction along the emission optical axis is applied to the entrance surfaces of the third optical member and the first optical member by a cylindrical lens surface 5 which gives a positive refractive power in the vertical direction.
By forming a and 6a, the light is converted so as to be parallel to the emission optical axis as shown.

On the other hand, a light beam having a large angle with respect to the exit optical axis is refracted by the entrance surfaces 5e and 6e of the third optical member and the first optical member, and then is reflected by the reflection surfaces 5d and
The luminous flux totally reflected at 6d and similarly emitted from the center of the light source is converted to be parallel to the emission optical axis in this cross section.

As described above, the light beam emitted from the center of the light source is once made parallel to the emission optical axis.
As shown in FIGS. 5 and 6, a first optical member (prism) 6
The irradiation angle range can be continuously changed depending on the shape of the exit surface and the shape of the incident surface of the second optical member 7.

First, in the peripheral portion in the horizontal direction shown in FIG. 5A, the exit surface 6 of the first optical member (prism) 6
Both b and the incident surface 7b of the second optical member 7 have no power in this cross section, and the most condensed state is maintained.

Also, near the center in the horizontal direction shown in FIG. 5B, a plurality of cylindrical lenses having a positive refractive power in the vertical direction formed on the exit surface of the first optical member (prism) 6. The surface 6c and the plurality of cylindrical lens surfaces 7c having a negative refractive power in the vertical direction formed on the second optical member 7 so as to cancel this power are formed. The state is maintained.

As a result, when the second optical members 7, 7 'corresponding to FIG.
(A) or the convergence state shown in FIG. 5 (b), which results in the most converged state.

On the other hand, as shown in FIG. 4, when the second optical members 7, 7 'are located at the farthest positions, FIG.
The first optical member (prism) 6 has no power with respect to the cross section 6b in the peripheral portion in the horizontal direction shown in FIG. 5, but the second optical member 7 has a plurality of cylindrical lenses having negative refractive power in the vertical direction. Since the light beam is constituted by the surface 7c, the light beam having passed through both surfaces is in a state of being diffused by the cylindrical lens surface 7c.

Also, in the vicinity of the center in the horizontal direction shown in FIG. 6B, a positive refractive power in the vertical direction formed at the center in the horizontal direction of the exit surface of the first optical member (prism) 6. A plurality of cylindrical lens portions 6c having a wide irradiation angle are provided by the plurality of cylindrical lens portions 6c.
Since this does not exist, this diffusion state is maintained.

As a result, in a state where the second optical members 7 and 7 'corresponding to FIG.
(A) or the diffusion state shown in FIG. 6 (b). As a result, a state where the irradiation angle range is the widest can be obtained.

Further, at each moving point other than the above two states, the ratio between the converging area range and the diffusing area range changes continuously, and the irradiation angle as a whole can also change continuously. .

As described above, the light distribution characteristics in the vertical direction can be obtained by moving the second optical members 7 and 7 ′ by a required amount in the horizontal direction with respect to the fixed first optical member (prism) 6. The irradiation angle can be changed effectively.

FIGS. 7 and 8 show actual light distribution characteristics obtained with such a configuration. 7 shows a state in which the irradiation angle range corresponding to FIGS. 3 and 5 is narrow, and FIG. 8 shows a state in which the irradiation angle corresponding to FIGS. 4 and 6 is wide.

As shown in the figure, it can be seen that the irradiation angle range changes greatly in the vertical and horizontal directions. Further, in the above-mentioned figure, the light distribution characteristics in the most converged state (FIG. 7) and the two most diffused states (FIG. 8) are shown. It is not limited to the state, and the characteristic between the two states can be continuously obtained according to the amount of movement of the second optical members 7, 7 '.

The movement of the second optical members 7 and 7 ′ in the above embodiment is shown to be symmetrical in the horizontal direction with respect to the emission optical axis, but the movement of the second optical members 7 and 7 ′ is The movement is not necessarily limited to such a symmetrical movement. For example, when the position of the photographing optical axis is different from the position of the illumination optical system, it is necessary to match the photographing optical axis with the optical axis center of the illumination optical system at a predetermined distance. To do
It is also possible to intentionally vary the amount of movement and obtain a light distribution characteristic that is asymmetrical in the left and right directions.

In the above embodiment, the exit surfaces of the second optical members 7 and 7 'are provided with the prism rows 7d and 7d' so as to have a convergence function. However, the present invention is not limited to the prism row, and may be constituted by, for example, a cylindrical lens surface having a constant curvature or a Fresnel lens.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIGS. 9 to 12
9 shows a lighting device according to a second embodiment of the present invention, in particular, a flash light emitting device 1 in this embodiment. FIGS. 9 and 10 are horizontal sectional views constituting an optical system of the flash light emitting device 1, and FIGS. ,
FIG. 12 is a vertical sectional view of the optical system of the flash issuing device 1. Note that FIGS. 9 to 12 also show ray trace diagrams of representative light rays emitted from the light source.

In the figure, reference numeral 22 denotes a cylindrical flash discharge tube (xenon tube) for emitting flash light, which has an effective arc length shorter than that of the flash discharge tube 2 shown in the first embodiment, and is about half as long. Use things.

Reference numeral 23 denotes a reflector for reflecting, in the light emitting direction, a light beam of the light beam emitted from the flash discharge tube 22 toward the rear of the central axis of the light source (the direction opposite to the object side), which is shown in the first embodiment. The flash discharge tube 22 is smaller than the reflector 3
It is a simple one that only covers the back half of
It does not extend to the rear of the optical member.

Reference numeral 26 denotes a condensing prism, which differs from the first embodiment and is constituted by a single component, and the incident surface has almost the same shape as that of the first embodiment, but near the center of the exit surface. Has a cylindrical lens surface 2 having a refractive power in the horizontal direction.
6b, Fresnel lens surfaces 26a, 26a 'having a refracting power in the horizontal direction are formed in a horizontal peripheral portion of the cylindrical lens surface 26b, and a vertical direction is formed in a horizontal peripheral portion of the exit surface. Is a first optical member in which a plurality of cylindrical lens surfaces 26c and 26c 'having a positive refractive power are formed.

Reference numerals 27 and 27 'denote second optical members arranged symmetrically with respect to the emission optical axis, and have a positive refractive power in the vertical direction of the first optical member (prism) 26 on the incident surface side. A plurality of cylindrical lens surfaces 27c, 27c 'having a negative refractive power in the vertical direction for canceling the refractive power of the plurality of cylindrical lens surfaces 26c, 26c' having Lens surface 26
a, 26a 'are formed. The second optical member 2
The reference numerals 7 and 27 ′ are arranged at a fixed distance from the exit surface of the first optical member (prism) 26, and are configured to be movable in the horizontal direction.

In the above configuration, the flash discharge tube 22, the reflector 2,
3. The first optical member (prism) 26 is integrated with a holding case or the like (not shown) to form a light emitting unit, and the second optical members 27 and 27 'are appropriately moved to a predetermined optical arrangement position to collect the light. It is possible to change the light intensity continuously. Further, the second optical member may be composed of a plurality of members.

As the material of the first optical member (prism) 26 and the second optical members 27 and 27 ', an optical resin material such as acrylic resin having high transmittance or a glass material is suitable. Are the same as in the first embodiment.

Similarly to the first embodiment, when the photographing lens of the photographing device 11 is a zoom lens, the second embodiment moves the second optical members 27 and 27 'in the horizontal direction according to the focal length. This is a proposal of an illuminating device in which the light distribution characteristics in the vertical and horizontal directions are simultaneously made to correspond to the photographing range of the photographing lens by appropriately adjusting the amount of movement of the photographing lens. The setting method will be described in more detail.

FIGS. 11 and 12 are vertical sectional views of a flashlight emitting device 1 according to a second embodiment of the present invention, showing the basic concept of changing the irradiation angle in the vertical direction. Note that FIG.
(A) and FIG. 11 (b) correspond to the EE section and the FF section in FIG. 9, and FIGS. 12 (a) and 12 (b) correspond to the GG section and the HH section in FIG. The number of each part is
This corresponds to FIG. 9 and FIG.

Here, the first optical member (prism) 26
The plurality of cylindrical lens surfaces 26c and 26c 'having a positive refractive power in the vertical direction formed in the exit portion are formed only in a region corresponding to the peripheral portion in the horizontal direction.

First, the state of light condensing and diffusion in the horizontal direction will be described with reference to FIGS. FIG. 9 is a diagram showing the most condensed state of the present invention.
7 shows a state where the optical member (prism) 26 has moved to a position corresponding to the peripheral portion of the optical member 26. In the first embodiment, the most condensed state is that the second optical members 7 and 7 'are arranged in contact with each other in the vicinity of the central portion of the light source, whereas they are arranged at exactly the opposite positions. Become.

In this state, the Fresnel lens surface provided near the center of the exit surface of the first optical member (prism) 26 (both horizontal peripheral portions of the cylindrical lens surface 26b), and the second optical member 27 , 27 ', the Fresnel lens surfaces provided on the exit surfaces of FIG.
As can be seen from the ray tracing diagram of FIG. 7, all the light beams emitted from the center of the light source are converted into light beams parallel to the optical axis.

Next, a state in which the irradiation angle range in the horizontal direction is the widest, that is, a state in which light is diffused the most, will be described with reference to FIG. The state shown here is a state in which the second optical members 27 and 27 ′, which are operation members for performing irradiation angle variation, have been moved to a position where they come into contact with the center of the first optical member (prism) 26.

As shown, the light beam emitted from the center of the light source is diffused. That is, the luminous flux in the central portion is divided into the first optical member (prism) 26 and the second optical members 27 and 27 ′.
While the light is diffused in the horizontal direction by the double Fresnel lens formed by the above, the luminous flux in the peripheral portion in the horizontal direction is converted into Fresnel lens surfaces 27a, 27a having a refractive power in the horizontal direction.
'Does not participate at all, the first optical member (prism) 2
6 is emitted as it is at the angle of incidence, and is emitted in a diffused state without a converging effect.

As a result, it can be seen that the emission angle distribution changes in the direction of widening as compared with the state obtained in FIG.

Next, the variable irradiation angle in the vertical direction which is changed in synchronization with the change in the irradiation range in the horizontal direction shown in FIGS. 9 and 10 will be described with reference to FIGS. 11 and 12.
In the figure, the same parts as those in FIGS. 9 and 10 are denoted by the same reference numerals.

The characteristics of the vertical cross-sectional shape shown in FIGS. 11 and 12 are substantially the same as those of the first embodiment. The exit surface of the first optical member (prism) 26 and the second optical member 2
Since only the combinations of the shapes of the incident surfaces 7 and 27 'are different, the description of this portion will be mainly given.

First, the light beam emitted from the center of the optical axis is the first light beam.
By the action of each surface of the optical member (prism) 26, the light is once converted into a light flux parallel to the emission optical axis. After that, the first optical member (prism) 26 and the second optical members 27 and 27 '
The condensing / diffusing state can be changed by the combination of. These states will be described in order.

As shown in FIG. 9, the second optical member 27,
FIG. 11A shows a state in which 27 ′ is at the farthest position.
In the peripheral portion shown in FIG. 9 (EE section in FIG. 9), a plurality of cylindrical lens surfaces having a positive refractive power in the vertical direction formed on the horizontal peripheral portion of the exit surface of the first optical member (prism) 26 26c and a plurality of cylindrical lens surfaces 2 having a negative refractive power and formed on the second optical member 27.
7c works just like power-off,
In this case, the most focused state is maintained.

In the vicinity of the center shown in FIG. 11B (the FF section in FIG. 9), the first optical member (prism) 26 has no power on this surface, and the second optical member 2 has no power.
Since neither 7 nor 27 'exists at this position, the most condensed state is maintained.

As a result, the second optical members 27 and 27 'corresponding to FIG. 9 move to a position corresponding to the horizontal peripheral portion of the exit surface of the first optical member 26, and in a state where they are separated from each other, All the regions correspond to FIG. 11A or FIG.
The convergence state shown in (b) is obtained, and as a result, the state is the most converged state.

On the other hand, as shown in FIG. 10, when the second optical members 27 and 27 'are at the closest position, the peripheral portion shown in FIG. The first optical member (prism) 26 is diffused by a plurality of cylindrical lens surfaces 26c having a positive refracting power in the vertical direction and formed on the periphery of the exit surface of the first optical member 26 in the horizontal direction. Since the member 27 is not present, the light spreads to a certain light distribution.

In the vicinity of the center shown in FIG. 12B (cross section taken along line HH in FIG. 10), the first optical member (prism) 26 has no power in this cross section, but the second optical member. Since the entrance surface of 27 is composed of a plurality of cylindrical lenses 27c having a negative refractive power in the vertical direction, the light beam after passing through both of them is in a state of being diffused by the cylindrical lens 27c.

As a result, when the second optical members 27 and 27 'corresponding to FIG. 10 are closest to each other, all the regions are in the diffused state of FIG. 12A or 12B, and As a result, a state where the irradiation angle range is the widest can be obtained.

Further, at each moving point other than the above two states, the ratio of the converging area range and the diffusion area range changes continuously, and the irradiation angle as a whole can also change continuously. .

As described above, the light distribution characteristics of the emitted light beam in the vertical direction are such that the second optical members 27 and 27 ′ are horizontal with respect to the fixed first optical member (prism) 26 with respect to the emitted optical axis. By moving a required amount in the direction, the irradiation angle can be continuously changed.

The second optical members 27 and 27 'of the above embodiment.
Has shown a symmetrical movement in the horizontal direction with respect to the emission optical axis, but the movement of the second optical members 27 and 27 'is not necessarily limited to such a symmetrical movement. It is also possible to intentionally vary the amount of movement and obtain a light distribution characteristic that is asymmetrical in the left and right directions.

In the above embodiment, the second optical member 2
Fresnel lens surfaces 27a, 27a on the exit surfaces 7 and 27 '
The exit surface is provided with a converging function, but the shape of the exit surface is not limited to such a Fresnel lens surface. For example, the exit surface may be constituted by a cylindrical lens surface having a constant curvature. By adopting such a configuration, it is possible to form an optical system with a small light amount loss.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. This embodiment is different from the second embodiment in that the second optical members 27 and 27 'are used.
Is a modified example in which the second optical member 27, 27 'which is the irradiation angle variable member in the second embodiment is composed of two members. It is characterized by comprising. Here, the state in which the irradiation angle in the vertical direction is variable is the same as that in FIGS. 11 and 12, and is omitted in this embodiment.

FIGS. 13 and 14 show a lighting device according to a third embodiment of the present invention, in particular, a flash light emitting device 1 in this embodiment. FIGS. 13 and 14 show the optical system of the flash light emitting device 1. It is a horizontal sectional view which comprises. FIG. 2 also shows a ray trace diagram of a representative ray emitted from the light source.

In the figure, reference numeral 37 denotes a second optical member, which is different from the second embodiment and is formed by a single member. The central part in the horizontal direction is a flat surface for both the incident and outgoing surfaces, and the peripheral part is a plurality of cylindrical lens surfaces 37c having negative refractive power in the vertical direction at the peripheral part in the horizontal direction of the incident surface, as in the second embodiment. , 37c 'are formed, and Fresnel lens surfaces 37a, 37a' having a refracting power in the horizontal direction are formed in the peripheral portion of the exit surface in the horizontal direction.

The second optical member 37 is arranged at a fixed distance from the exit surface of the first optical member (prism) 26, and is configured to be movable in the horizontal direction. I have.

On the other hand, in the same manner as in the second embodiment, a plurality of cylindrical lens surfaces having a positive refractive power in the vertical direction are provided in the region around the exit surface of the first optical member (prism) 26 in the horizontal direction. 26c and 26c 'are formed. Also,
Other components are the same as in the second embodiment.

In the above configuration, the flash discharge tube 22, the reflector 2,
3. The first optical member (prism) 26 is integrated with a holding case (not shown) or the like to form a light emitting unit, and the second optical member 37 is slid horizontally to change the degree of light collection. Will be possible. In this embodiment, in the above two states, optical characteristics substantially equivalent to those of the second embodiment can be provided. However, at an intermediate stage during movement, the left and right light distribution characteristics in the horizontal direction have an asymmetric shape, Apart from the case where a special change in light distribution characteristics is desired, it is not suitable as a method for continuously changing light distribution characteristics in a continuous manner, particularly in the horizontal direction.

Hereinafter, the state of light converging and diffusing in the horizontal direction will be described with reference to FIGS. FIG. 13 is a diagram showing the most condensed state of the present invention, in which the second optical member 37 that changes the irradiation angle is a first optical member (prism).
26 shows a state in which it is arranged at a position directly overlapping with directly facing 26. In this state, a cylindrical lens surface 26b having a refractive power in the horizontal direction is formed near the center of the exit surface of the first optical member (prism) 26,
Fresnel lens surface 26 having a refractive power in the horizontal direction provided on the peripheral portion in the horizontal direction of cylindrical lens surface 26b
Due to the convergence effect of the Fresnel lens surfaces 37a, 37a 'provided on the exit surface of the second optical member 37, the light beam emitted from the center of the light source is converged as shown in the ray trace diagram of FIG. Has been converted to a state.

Next, a state where the irradiation angle range in the horizontal direction is wide, that is, a state where light is diffused the most will be described with reference to FIG. The state shown here is such that the second optical member 37, which is an operation member for changing the irradiation angle, is such that the right end of the first optical member (prism) 26 in the horizontal direction is the center plane of the second optical member 37. It is in a state where it has been moved to a matching position.

As shown, the light beam emitted from the center of the light source is largely diffused. That is, the central portion is diffused by the double Fresnel lens formed by the first optical member (prism) 26 and the second optical member 37, while the peripheral portion in the horizontal direction does not involve the Fresnel lens at all. Since the light enters the first optical member (prism) 26 and is emitted as it is at an angle in a refracted state, the light is emitted in a state of being diffused without a convergence effect. As a result, it can be seen that the emission angle distribution is significantly changed as compared with the state obtained in FIG. Incidentally, a prism array having a refractive power in the horizontal direction may be arranged long in the vertical direction on the exit surface of the second optical member and may be similarly diffused.

In the third embodiment, the embodiment in which the second optical member is constituted by one member has been described. In this way, even with a single component, the most focused state and the most diffused state can be realized, and the simultaneous irradiation angles in the vertical and horizontal directions can be achieved with a simple operation of simply sliding one part left and right. It is possible to realize an illumination optical system which can be changed and has a large change in irradiation angle in a limited space.

[0127]

As described above, according to the present invention,
The irradiation angle can be efficiently varied for the light source having a long effective light emitting section.

In particular, this is effective when applied to a small and thin illumination optical system in which the space required for changing the irradiation angle is limited, and the irradiation angle can be largely changed with a simple configuration. .

Further, when applied to the irradiation angle variable mechanism of the flash light emitting device 1, the irradiation angle in the horizontal direction can be controlled in synchronization with the variable irradiation angle in the vertical direction, so that irradiation in the vertical and horizontal directions can be performed without increasing the space. The angle can be changed, and a large guide number can be expected in the focused state.

Further, the illuminating device having a variable illumination angle, which is excellent in optical characteristics, such as being capable of continuously changing the change of the light distribution characteristics and being capable of obtaining a uniform light distribution at all zoom points. Can now be offered.

Further, the illumination optical system having a variable irradiation angle according to the present invention has a high degree of design freedom, and it is easy to design an optimum irradiation angle variable mechanism according to the size, mechanical accuracy, optical characteristics, and the like required for a product. It can be carried out.

Further, the technology is extremely versatile because it has a small number of components and can be configured at a low cost with a variable irradiation angle mechanism, and its application optical system is wide and can be applied to various illumination optical systems. It has become possible to provide an illumination device suitable for optical devices such as a still camera and a video camera, which utilize energy with high efficiency, and an imaging device using the same.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a camera to which a flash light emitting device according to a first embodiment of the present invention is applied.

FIG. 2 is a perspective view of a main part of an optical system of the flash light emitting device according to the first embodiment of the present invention.

FIG. 3 is a horizontal sectional view of the flash light emitting device according to the first embodiment of the present invention, corresponding to a narrow irradiation angle.

FIG. 4 is a horizontal cross-sectional view of the flash light emitting device according to the first embodiment of the present invention, corresponding to a wide irradiation angle.

FIG. 5 is a vertical cross-sectional view of the flash light emitting device corresponding to a narrow irradiation angle according to the first embodiment of the present invention.

FIG. 6 is a vertical cross-sectional view of the flash light emitting device according to the first embodiment of the present invention, corresponding to a wide irradiation angle.

FIG. 7 is a light distribution characteristic diagram of the flash light emitting device corresponding to a narrow irradiation angle according to the first embodiment of the present invention.

FIG. 8 is a light distribution characteristic diagram of the flash light emitting device corresponding to a wide irradiation angle according to the first embodiment of the present invention.

FIG. 9 is a horizontal cross-sectional view of a flash light emitting device according to a second embodiment of the present invention, corresponding to a narrow irradiation angle.

FIG. 10 is a horizontal sectional view of a flash light emitting device according to a second embodiment of the present invention, corresponding to a wide irradiation angle.

FIG. 11 is a vertical sectional view of a flash light emitting device according to a second embodiment of the present invention, corresponding to a narrow irradiation angle.

FIG. 12 is a vertical sectional view of a flash light emitting device according to a second embodiment of the present invention, corresponding to a wide irradiation angle.

FIG. 13 is a horizontal sectional view of a flash light emitting device according to a third embodiment of the present invention, corresponding to a narrow irradiation angle.

FIG. 14 is a horizontal sectional view of a flash light emitting device according to a third embodiment of the present invention, corresponding to a wide irradiation angle.

[Explanation of symbols]

 2, 22 Flash discharge tube 3, 23 Reflector 4, 4 'Fourth optical member (reflector) 5, 5' Third optical member (prism) 6, 26 First optical member (prism) 7, 7 ', 27, 27', 37 Second optical member

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03B 15/02 G03B 15/02 QRS 15/03 15/03 F 17/02 17/02 H04N 5 / 238 H04N 5/238 Z (72) Inventor Takayuki Uchida 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Nobuhisa Kojima 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon F term in reference (reference) 2H053 CA02 CA08 CA12 CA13 CA41 CA44 CA45 2H100 AA01 BB05 BB06 BB07 5C022 AA13 AB15

Claims (20)

[Claims] 1. An illuminating device having a variable irradiation angle for converting a light beam from a light source unit into a predetermined irradiation angle via an optical unit and irradiating the light beam, wherein the light source unit has a tubular luminous body elongated in a horizontal direction. An illumination unit having a variable irradiation angle, wherein the optical unit is located on a subject side of the light source unit and has an optical member movable in a horizontal direction. 2. The optical unit includes a first optical member and a second optical member in order from the light source unit toward a subject.
The first optical member is formed with a refractive power in the horizontal direction,
The second optical member is disposed in a pair symmetrically with respect to the emission optical axis of the light source means in the horizontal direction, and the second optical member is symmetrically movable with respect to the emission optical axis in the horizontal direction. The illumination device according to claim 1, wherein the illumination angle is variable. 3. The optical unit includes a first optical member and a second optical member in order from the light source unit toward a subject.
The first optical member comprises a trapezoidal prism member having an inclined surface so that a space in a horizontal section between the light source means and the first optical member expands toward both peripheral portions in the horizontal direction. The second optical member is disposed in a pair in the horizontal direction symmetrically with respect to the emission optical axis of the light source means, and the second optical member is movable symmetrically in the horizontal direction with respect to the emission optical axis. The illumination device according to claim 1, wherein the illumination angle is variable. 4. An optical system comprising: a first optical member and a third optical member;
A first optical member having an inclined surface such that a space in a horizontal section between the light source means and the first optical member expands toward both peripheral portions in the horizontal direction. The third optical member is composed of two prisms having a triangular horizontal cross section, and the third optical member is located at both horizontal peripheral portions of the first optical member. The illumination with a variable irradiation angle according to claim 1, wherein an air layer is provided between the longest inclined surface of the first optical member and the inclined surface of the first optical member so as to face each other. apparatus. 5. The optical means includes a first optical member, a second optical member, a third optical member, and a fourth optical member, wherein the first optical member includes the light source and the light source. A space in a horizontal section between the first optical member and the first optical member is formed of a trapezoidal prism member having an inclined surface such that the space expands toward both peripheral portions in the horizontal direction; and the second optical member is the first optical member. The third optical member is symmetrically formed with respect to the emission optical axis of the light source means so as to be movable in the horizontal direction, facing the emission surface of the member, and the third optical member emits light at both ends in the horizontal direction of the light source means. Facing the body, the prism is composed of two prisms each having a triangular horizontal cross section symmetrically with respect to the optical axis of light emitted from the luminous body, the longest slope of the triangle and the first prism.
The fourth optical member faces the outer surfaces of the third optical member in the horizontal direction, and the emission optical axis faces the inclined surface of the third optical member. The illuminating device according to claim 1, wherein the illuminating device has a variable illumination angle. 6. A Fresnel lens surface is formed in a horizontal peripheral area on an exit surface of the movable second optical member, and a prism array is formed in a horizontal central area. The illumination device according to claim 2, wherein the illumination angle is variable. 7. The movable Fresnel lens surface and the prism array provided on the movable second optical member are formed so as to have a refracting power with respect to a horizontal cross section. 3. The illumination device according to claim 1, wherein the illumination angle is variable. 8. The illumination with a variable irradiation angle according to claim 1, wherein the movable optical member comprises a plurality of members that move in a horizontal direction, and moves symmetrically with respect to an emission optical axis. apparatus. 9. The apparatus according to claim 1, wherein the total length of the movable exit surface of the second optical member is substantially half the length of the exit surface of the first optical member. Item 6. An illumination device with a variable irradiation angle according to item 2, 3 or 5. 10. A light-emitting body optical axis behind said light source means,
6. A umbrella for reflecting a light beam emitted from a light source, and the shape of the umbrella at least partially forms a reflecting surface concentric with the center of the light source. 3. The illumination device according to claim 1, wherein the illumination angle is variable. 11. An illumination device having a variable irradiation angle for converting a light beam from a light source unit into a predetermined irradiation angle via an optical unit and irradiating the light beam, wherein the light source unit has a horizontally long tubular luminous body. The optical means has a first optical member and a second optical member in order from the light source means to the object side, and the first optical member is arranged with the short side facing the light source means. The second optical member is disposed facing the subject side of the first optical member, and is movable in the horizontal direction so as to be paired symmetrically with respect to the emission optical axis. An illumination device having a variable irradiation angle, which is formed. 12. A cylindrical lens surface is formed vertically long so as to have a horizontal refracting power at a horizontal center portion of an exit surface of the first optical member, and a peripheral portion of the cylindrical lens surface in a horizontal direction is provided. The illuminating device according to claim 11, wherein the Fresnel lens surface is formed in the portion to be long in a vertical direction so as to have a refractive power in a horizontal direction. 13. The irradiation angle variable according to claim 11, wherein a Fresnel lens surface is formed to be long in a vertical direction so as to have a refracting power in a horizontal direction on an exit surface of the second optical member. Lighting equipment. 14. An illumination device with a variable illumination angle for converting a light beam from a light source device into a predetermined illumination angle via an optical device and irradiating the light beam, wherein the light source device has a horizontally long tubular luminous body. The optical means has a first optical member and a second optical member in order from the light source means to the object side, and the first optical member is arranged with the short side facing the light source means. Irradiation having a trapezoidal shape in the horizontal cross section, wherein the second optical member is disposed so as to face the emission surface of the first optical member and is provided so as to be movable in the horizontal direction. Variable angle lighting device. 15. A cylindrical lens surface is formed at a central portion in a horizontal direction of an exit surface of the first optical member so as to be vertically elongated so as to have a refracting power in a horizontal direction, and a peripheral portion of the cylindrical lens surface in a horizontal direction is provided. 15. The illumination device according to claim 14, wherein the Fresnel lens surface is formed in the portion to be long in a vertical direction so as to have a refractive power in a horizontal direction. 16. The Fresnel lens surface is formed vertically long so as to have a refracting power in the horizontal direction at both peripheral portions in the horizontal direction of the exit surface of the second optical member. 15. The illumination device according to 14, wherein the illumination angle is variable. 17. The light source according to claim 1, wherein the light source is a flash tube having a straight tubular shape.
The illumination device with a variable irradiation angle according to claim 4. 18. An illumination device with a variable irradiation angle for converting a light beam from a light source means to a predetermined irradiation angle via an optical means, and irradiating the light means, wherein the optical means is positioned on a subject side with respect to the light source means. And
The irradiation angle can be changed from a position facing the front of the light source means to a position of a peripheral part in a horizontal direction of the optical means, and a plurality of prism rows are formed on an emission surface of the optical means. Lighting equipment. 19. The illuminating device according to claim 1, wherein the illuminating device according to any one of claims 1 to 18 changes the illuminating angle in the vertical and horizontal directions. 20. An imaging device comprising the illumination device with a variable irradiation angle according to claim 1. Description: