JP2000292835A - Illumination device for camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination device for camera by which the efficiency can be enhanced by condensing direct light being the primary light emitted outside a photographing viewing angle within the viewing angle. SOLUTION: By providing the illumination device of the camera with a 2nd reflection member (sub-reflector 2) arranged adjacently to a flash discharge tube for reflecting luminous flux from the flash discharge tube to a 1st reflection member (main reflector 1) side in addition to the 1st reflection member for reflecting the luminous flux from the flash discharge tube to an object side, the direct light emitted outside the photographing viewing angle is reflected so as to be condensed within the desired narrow viewing angle by the cooperation of the 1st and the 2nd opposed reflection members.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device for a camera, for example, utilizing the function of a reflector.

[0002]

2. Description of the Related Art As a technique related to a lighting device of a camera in recent years, for example, there is a technology taught in Japanese Patent Laid-Open No. Hei 6-82883. In order to suppress irradiation of light, it has a light shielding plate integrally molded with a mold for shielding unnecessary light,
It is characterized by a structure that allows light to pass directly through the central opening of the light-shielding plate. Therefore, the illuminating device having this structure could mainly illuminate the subject within the angle of view.

[0003]

However, such an illuminating device is used for telephoto photography with a narrow light distribution angle, for example, as shown in FIG.
In an apparatus having an irradiation range of, a particularly required light distribution angle is vertically narrow (in the example of FIG.
In the case of (°) or the like, a state in which a part of the direct light (that is, light in a range indicated by a hatched line) is wasted may occur. In other words, the direct light applied to the characteristic light shielding plate disposed in front of the light source is blocked by the light shielding plate and does not reach the subject,
Although the glare perceived by the subject is suppressed, the luminous flux hitting the light-shielding plate is substantially wasted and is not effectively used for subject illumination. Therefore, the reduction in power consumption, which is the objective of such a conventional lighting device, has not been achieved.

In order to achieve a narrow light distribution angle, when the curved shape of the reflecting member behind the light source is further narrowed, the size of the reflecting member in the X direction increases, and the size of the lighting device itself becomes large. Cause the

Accordingly, an object of the present invention is to condense primary light (ie, direct light) emitted outside the angle of view into the angle of view,
An object of the present invention is to provide a lighting device capable of improving lighting efficiency.

[0006]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention takes the following measures. According to one aspect of the present invention, for example, a first reflecting member for reflecting a light beam of a flash discharge tube to a subject side and a second reflecting member which is adjacent to the flash discharge tube and reflects a light beam from the discharge tube to the first reflecting member side. A lighting device for a camera comprising two reflecting members is proposed. The second reflection member has an opening through which the emitted light beam passes, and proposes a lighting device for a camera.

According to the present invention, for example, a first reflecting member for reflecting a light beam from a flash discharge tube to the subject side, a reflecting surface facing the reflecting surface of the first reflecting member, and one of the light beams is provided. And a second reflection member having an opening through which the portion passes.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The gist of the present invention will be described in detail below with reference to a plurality of embodiments relating to a lighting device for a camera. (First Embodiment) FIG. 1 shows the structure of an illuminating device (flash device) provided with a flash discharge tube as an example of the illuminating device of the first embodiment, and its optical reflection function. FIG. 2 shows the appearance of the lighting device of the first embodiment.

At least this lighting device for a camera is a device using a discharge tube as a light source (illuminant) 3 as a light source. A main reflector 1 having a concave surface of a substantially rectangular parallelepiped as shown in FIG. 1 is arranged as a first reflecting member adjacent to the illumination element 3 and is configured to converge reflected light in a subject direction (X direction). I have.

Further, in the lighting device of the present invention, a sub-reflector 2 defining a light distribution vertical angle of 12 ° and having a reflecting function is installed in a shape having a central opening as a second reflecting member. The light once reflected by the reflector 2 in the direction of the main reflector 1 is reflected by the main reflector 1 again toward the subject.

FIG. 2 shows an example of an actual flash illuminating device as an example of a flash device employing a flash discharge tube, for example, a xenon tube (Xe tube) 3 as an illuminating element. The main reflector 1 of this device is composed of a main reflector 1a having a parabolic vertical cross section provided behind the effective light-emitting surface of the xenon tube 3, and side reflectors 1b provided on both sides thereof and opened forward. It is made of an aluminum thin plate or the like having a mirror-finished inside so as to be able to irradiate a direct light and a reflected light from the xenon tube 3 to a predetermined range (narrow angle range) narrow toward the subject direction.

The sub-reflector 2 which is a feature of the lighting device exemplified here is provided with a central opening 2 as shown in FIG.
a is formed along the light emission center axis of the xenon tube 3 (details will be described later), and its inner surface or preferably both surfaces are mirror-finished, and are made of an aluminum thin plate or the like.
The sub-reflector 2 is disposed in front of the xenon tube 3 and has a curved shape cut out at a central opening 2a so as to allow direct light of a narrow predetermined range (12 °) toward the subject to pass through without being blocked. The arrangement is arranged at a position almost in contact with the xenon tube 3. The central opening 2a is provided in a slit shape extending horizontally across the light emitting axis (that is, a line connecting the center of the light source and the subject).

In order to mount the main reflector 1 and the sub-reflector 2, the sub-reflector 2 has a portion projecting forward as a positioning portion 4 between these two types of reflectors (details will be described later). Further, a rubber band 5 is applied to the back of the main reflector 1,
Terminals 3a (and 3b (not shown)) on both sides of the xenon tube 3 are attached by projecting from two holes provided at both ends of the rubber band 5, respectively.

Each of the members constituting the above-described lighting device will be described in more detail with reference to FIGS.
First, according to the longitudinal sectional structure of the illumination device (strobe device) of the first embodiment shown in FIG. 3A, this device includes one main reflection portion 1a and two side reflection portions 1b. This main reflector 1 and one sub reflector 2
As a reflection member. The effective light emission range of the xenon tube 3 as a lighting element is included in the curved inside of the main reflector 1. A substantially same area is in contact with the inner surface by the sub-reflector 2. The positioning portion 4 formed on the sub-reflector 2 is fitted into the notch of the both-side reflecting portion 1b of the main reflector 1.

The sub-reflector 2 is a member formed of a heat-resistant metal plate such as a thin aluminum plate, and has a mirror-finished inner surface facing at least the xenon tube 3. The plurality of reflecting members are correctly positioned by the positioning portion 4 in a predetermined positional relationship, and are integrally held together with the xenon tube 3 by a rubber band 5 horizontally applied to the upright bent portion 1c of the main reflector 1. You can see that it is done.

This strobe device also has a lead wire 6 connected to a power supply circuit (not shown) for supplying light emission power to the xenon tube 3 and a trigger for triggering the main reflector 1 for flash light emission operation. Trigger line (7: described later)
And are connected.

FIG. 3 (b) shows a cross-section of the xenon tube 3 as viewed from the front, and its shape characteristics can be understood. Reference numeral 3c denotes an effective light emitting portion of the xenon tube 3, and terminals 3a and 3b of the xenon tube 3 project from both ends.

Further, according to the partial appearance of the sub-reflector 2 shown in FIG. 3 (c), a positioning portion 4 which is formed almost vertically and bent near both ends of the central opening 2a of the sub-reflector 2. Are projected forward, and are formed so as to position the main reflector 1 (1b) and the sub-reflector 2 at the upright bent portion of the positioning portion 4.

The lighting device exemplified here is a strobe device for a camera, and is usually a main body (not shown) of a camera or the like.
It is designed to be mounted on the top or inside of a device, and is particularly conceived to be small in size and have high lighting efficiency.

(Function and Effect 1) The main feature of the lighting device exemplified in this way is that the sub-reflector 2 constituting this device is
And its shape, and its location. First, in terms of the configuration, the reflecting member of this lighting device is composed of a normal first reflecting member (main reflector 1) disposed behind the xenon tube 3 and another second reflecting member (sub reflector 2).
It is composed of two types.

Therefore, in order to emit light to a subject whose required light distribution angle is in a relatively narrow angle range of 12 degrees each in the upper and lower directions, such as a strobe device for telephotography, in addition to the main reflector 1, In addition, by arranging the sub-reflector 2 as described above at a position facing the main reflector 1 with the xenon tube 3 interposed therebetween, the following operation and effect are exhibited. That is, the main reflector 1 composed of the main reflection portion 1a and the side reflection portion 1b and having a cross-sectional shape such as a parabola or a hyperbola transmits the light diffused from the xenon tube 3 to a wider range than a desired narrow range through the sub-reflector 2. As a result, the light can be reflected so as to converge on a narrow range in front.

That is, the sub-reflector 2 having the two-sided reflecting portions 2b which are curved and approximate to the surface curvature of the xenon tube 3 symmetrically with respect to the X axis directs the direct light in the X direction through the slit-shaped central opening 2a. The two-sided reflection portions 2b provided separately on both sides of the central opening portion 2a reflect the direct light which spreads out of a narrow predetermined range toward the main reflector 1 side. This allows the reflected light to be reflected forward again by the main reflector 1, thereby effectively illuminating the subject.

Since the xenon tube 3 used here is a transparent glass tube filled with a transparent gas and has transparency, the reflected light from the sub-reflector 2 passes through the inside of the xenon tube 3 efficiently. Since the light hits the main reflector 1, the presence of the xenon tube 3 hardly hinders the light, but the light is refracted a plurality of times by the transparent glass tube as shown in FIG.

As described above, according to the first embodiment, FIG.
By arranging the sub-reflector 2 in the same axis as that of the xenon tube 3 as shown in FIG. 1, the sub-reflector 2 is not required as direct light from the xenon tube 3 and has a vertical angle of 38 ° from 12 ° to 50 °. The light beam can be reflected and converged by the main reflector 1 via the sub reflector 2 toward the center in the X direction.

Therefore, these reflected lights are emitted at a relatively small angle (for example, 0 ° to 3 °) with respect to the X-axis direction as shown by arrows A and B in FIG. 1 and converge toward the subject. As a result, primary light (that is, direct light) that is originally widely diffused can be used for illumination without waste. Further, the reflector composed of a plurality of reflecting members can be easily and accurately positioned at the bent portion of the positioning portion 4 provided on the sub-reflector 2, and the assembly becomes easy.

As a result, it is possible to provide an illuminating device for a camera that can improve the illumination efficiency by condensing the light emitted outside the desired angle of view into the angle of view.

(Modification 1) The configuration of the illumination device of the first embodiment described above may be modified as follows. As one modified example illustrated in FIG. 4, a main reflector 1 and a sub-reflector 2 among components constituting the lighting device are shown. The main feature as a modification of the lighting device exemplified here is that a part of the main reflector 1 and the sub-reflector 2 are integrally formed.

More specifically, FIG. 4 shows an assembling diagram of a strobe device as a modification of the above-described first embodiment. That is, according to this structural modification, the sub-reflector 2 is formed integrally with the above-mentioned both-side reflecting portion 1b, and this is extended and extended to both ends of the sub-reflector 2, and the sub-reflector 2 is positioned at (That is, 1b). Therefore, by positioning and fixing to the holding stand (not shown) on the camera body side by the positioning portions of the sub-reflector 2 provided at these both ends,
The central opening 2a can also be fixed accurately at the same time.

The sectional view of FIG. 5 shows the longitudinal sectional structure of the illuminating device according to the first modification. As shown in the figure, the supplied electric power is supplied to the supply circuit (not (Shown). On the other hand, the trigger line 7 is directly connected to the ends of the two-sided reflection portions (1b) which are a part of the sub-reflector 2, so that a trigger can be applied via the sub-reflector 2.

According to the first modification, the sub-reflector 2
And the two-sided reflectors 1b of the main reflector 1 have an integral structure, so that the two-sided reflectors 1b, which are a part of the main reflector 1 in the first embodiment described above, and the sub-reflectors 2
Alignment with the sub-reflector 2
To trigger. In addition, the standing portion is not required to be bent as described above. According to the first modification, an effect equal to or more than that of the first embodiment can be expected.

(Second Embodiment) FIG. 6 is a cross-sectional view illustrating a camera illumination device as a second embodiment. The main feature of the strobe device shown here is that the cross-sectional shape of the sub-reflector 2 is formed in a simple shape as shown in the figure without slits. In other words, the sub-reflector 2 is formed in a cross-sectional shape like a part of a cylindrical shape having a radius of curvature smaller than the outer diameter of the xenon tube 3 to be used, and the central opening as in the first embodiment described above. (2a) is a shape not having.

The sub-reflector 2 contacts or approaches the outer periphery of the xenon tube 3 at two points as shown in the figure, and the reflection surface itself on the inner surface does not contact the outer periphery, but forms an arc shape. I have. The primary light that is to be irradiated in the X direction is also reflected in the opposite direction, passes through the xenon tube 3, and is condensed again by the main reflector 1 in a desired narrow range (for example, 12 °) in the X direction. It is configured to be.

(Function and Effect 2) According to the second embodiment, the sectional shape of the sub-reflector 2 is formed as a series of small curved mirror surfaces without slits, and the sub-reflector 2 faces the xenon tube 3 and is positioned on the X axis. The following effects can be obtained by arranging them.

First, the reflected light is X-shaped as indicated by the arrow in FIG.
The light is emitted at an extremely small angle (for example, 0 ° to 1 °) with respect to the direction and converges toward the subject. = 46 ° -12 °) can also be used for illumination without waste. Therefore, it is understood that the primary light can be collected in an extremely narrow range without providing the slit (the central opening 2a) as in the first embodiment.

The sub-reflector 2 having a continuous curved surface having a smaller radius of curvature than the shape provided with the central opening improves the light collecting function for efficiently collecting the reflected light rays in a narrower range. Therefore, illumination for concentrating a larger amount of light in a narrower range becomes possible, which can contribute to an increase in the luminance of the subject.

Further, since the shape of the sub-reflector 2 itself is further simplified, workability is improved. As a result, it is possible to easily provide an illuminating device capable of increasing the illumination efficiency by condensing the primary light within a narrow angle of view.

(Modification 2) In this embodiment, if a mirror surface having a small radius of curvature as described above is provided, this sub-reflector is formed in a shape in which a slit is provided at the center as in the above-described first embodiment. It is also possible to form such a modification, and it is possible to expect substantially the same effect as the above-described first and second embodiments in the reflection function even by such a modification.

(Third Embodiment) FIG. 7 shows a structure of a camera illumination device according to a third embodiment and its reflection function. One feature of the third embodiment is that the sub-reflector 2 is provided so as not to be in contact with the xenon tube 3 but to be floated at a position separated from the peripheral surface of the xenon tube 3. Another feature is that a slit as in the first embodiment is provided at the center of the sub-reflector 2, and the cross-sectional shape of each of the sub-reflectors 2 is a flat plate having no curved surface. Further, the xenon tube 3 is attached to the main reflector 1 so as to be in contact on the X axis.

(Function and Effect 3) The reflected light has a relatively small angle (for example, 0 °) with respect to the X direction as shown by the arrow in FIG.
１６16 °), the light that is emitted toward the subject and passes through the central slit, and the primary light in the range of 26 ° (= 38 ° −12 °) in the upper and lower 38 °, which naturally diffuses widely, is also included. It turns out that it can be used for lighting.

As described above, according to the third embodiment, the sub-reflector 2 is mounted in a floating state without contacting the xenon tube 3. It is easier to achieve higher precision when machining than a curved mirror surface with curvature.

The other effects obtained from the third embodiment are substantially the same as those of the above-described embodiment.

(Modification 3) Of the three features of the third embodiment, any one or two of them may be combined, and an effect equivalent to that of the third embodiment is expected. it can. For example, the xenon tube 3 does not necessarily have to be in contact with the main reflector 1. Conversely, even if it is in contact with the main reflector 1, the sub-reflector 2 does not necessarily have to be a flat plate. In addition, even if a planar sub-reflector 2 is used, the xenon tube 3 is connected to the sub-reflector 2.
You may be in contact with. In addition, a combination of the cross-sectional shape of the sub-reflector 2, the presence or absence of the opening, and the distance from the main reflector 1 and other modifications can be made as long as the desired effect is obtained.

(Fourth Embodiment) FIGS. 8A and 8B illustrate a lighting device as a fourth embodiment. In this example, the second reflecting member of the present invention is applied to a xenon tube itself. That is, as shown in FIG. 8 (a), this is one in which a reflecting portion 10 provided with a predetermined reflecting substance is integrally provided on the surface of a long and thin cylindrical xenon tube 3, while a slit-like portion is provided. At the center, there is a transmission section 9 to which no reflective substance is attached. However, the same main reflector (not shown) as the first reflecting means is used, and its arrangement position may be the same as that of the above-described embodiment.

Although the thickness of the reflecting portion 10 is emphasized in the cross-sectional view shown in FIG. 8B for the sake of description, it is actually a portion having a mirror surface having an extremely thin film thickness, and is resistant to light emission. The obtained heat-resistant reflective material is formed on the surface of the xenon tube 3 by sputtering, printing, vapor deposition or the like.

(Function and Effect 4) According to the fourth embodiment, as described above, by forming the reflecting portion 10 on the illumination element itself, the reflecting portion 10 becomes a portion which works in the same manner as the sub-reflector 2 described above. On the other hand, the transmitting portion 9 works in the same manner as the slit at the central opening 2a. That is, the function of the above-mentioned sub-reflector 2 can be integrated by providing a portion having extremely excellent reflectivity and heat resistance on the outer periphery of the xenon tube 3. Therefore, it is not necessary to separately manufacture the sub-reflector 2 in terms of the configuration, so that the number of manufacturing and assembling steps can be greatly reduced.

The reflecting section 10 is not necessarily a xenon tube 3
May be formed on the inner peripheral surface instead of the outer peripheral surface. As a result, it is possible to provide an illuminating device that improves the illumination efficiency by condensing the primary light within a narrow angle of view with a simpler configuration.

(Modification 4) The fourth embodiment may be modified as shown in FIG. 9, and the same effect can be expected. The same main reflector (not shown) is used as the first reflecting member. In particular, a spherical light source is used as the illumination element 3 of the illumination device, and the illumination element 3 itself has a reflection function equivalent to that described above. It is the one with. This example is a so-called “bean ball” type xenon tube 8
This is an example in which the concept of the present invention is applied to a xenon tube 8 of this type.

That is, the spherical illumination element 8 of the bead type is adopted as the light source, and the surface of the spherical illumination element 8 has
A round transmitting portion 9 for passing the light beam as it is, and a circular reflecting portion 10 surrounding this portion with a predetermined reflecting material
And formed of a heat-resistant reflective material by the same processing method as described above. By integrally forming the second reflecting portion in this way, even in the case of a bead type illumination element, the same or higher effects as in the fourth embodiment can be exerted even with a point light source other than the linear light source.

(Other Modifications) The illumination element is not necessarily limited to a flash illumination element such as a xenon tube.

The illustrated light distribution angle is not limited to the upper and lower 12 °. A desired light distribution angle on the left and right (horizontal) may be realized by modifying the gist similar to that described above.

In addition to the modification of the sub-reflector, the light distribution / condensing function can be adjusted by changing the shape and the like of the main reflector.
In addition, various modifications can be made without departing from the spirit of the present invention.

Although the embodiments have been described above, the present invention includes the following inventions and can provide such a lighting device. (1) Illumination of a camera including: a first reflecting member that reflects a light beam of a light source toward a subject; and a second reflecting member that is adjacent to the light source and reflects the light beam from the light source toward the first reflecting member. Device.

(2) The first reflecting member and the second reflecting member
The lighting device according to (1), wherein the reflecting member is disposed at a position sandwiching the light source in the optical axis direction with the respective mirror surfaces facing each other.

(3) The lighting device according to any one of (1) and (2), wherein the second reflecting member has an opening through which a light beam emitted from the light source passes. is there.

(4) The illumination device according to any one of (1) and (2), wherein the second reflecting member has a flat mirror surface separated from the outer periphery of the light source.

(5) The lighting device according to any one of (1) and (2), wherein the second reflecting member has an inwardly curved mirror surface that is equal to or less than an outer peripheral curvature of the light source.

(6) The lighting device according to any one of (1) and (2), wherein the light source is a point light source or a line light source.

(7) The lighting device according to (1), wherein the second reflecting member is formed on a peripheral surface of the light source.

(8) The second reflecting member has an arc-shaped or flat plate-shaped cross section, and is disposed adjacent to the light source.
(1) The lighting device according to (1), which is configured to reflect a part of the direct light from the light source toward the first reflecting member.

(9) The light source is a xenon tube or a flash illuminator similar thereto. (1)
2. The lighting device according to item 1.

(10) The illumination device according to (9), wherein the xenon tube is configured to apply a trigger voltage from a trigger connected to the second reflecting member.

(11) The second reflecting member is not provided as an independent member, but is formed by forming an equivalent functional portion of the second reflecting member on the glass peripheral surface of the xenon tube by sputtering or vapor deposition. The lighting device according to (9).

[0063]

As described above, according to the present invention, it is possible to increase the efficiency of illumination by condensing primary light, that is, direct light, radiated outside the angle of view, within the angle of view. An illumination device for a camera can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a structure and a function of a lighting device of a camera according to a first embodiment of the present invention.

FIG. 2 is an exemplary perspective view showing the appearance of the illumination device of the camera according to the first embodiment;

3 (a) to 3 (c) show a main part of the lighting device, FIG. 3 (a) is a cross-sectional view showing a cross-sectional structure in a longitudinal direction of the lighting device, and FIG. FIG. 3C is a front view showing the shape of the xenon tube, and FIG. 3C is a perspective view showing the appearance of the sub-reflector.

FIG. 4 is an exemplary perspective view showing assembling of components of a lighting device as a modification of the first embodiment;

FIG. 5 is a cross-sectional view showing a cross-sectional structure in a longitudinal direction of a lighting device according to a modified example.

FIG. 6 is an explanatory view showing a structure of a lighting device of a camera according to a second embodiment of the present invention and its reflection function.

FIG. 7 is an explanatory diagram showing a structure of a lighting device of a camera according to a third embodiment of the present invention and its reflection function.

FIGS. 8A and 8B show a lighting element according to a fourth embodiment of the present invention, and FIG. 8A is a perspective view showing an external appearance of a xenon tube, and FIG. 2 is a cross-sectional view of the xenon tube.

FIG. 9 is an exemplary perspective view showing the appearance of a lighting element according to a modification of the fourth embodiment;

FIG. 10 is an explanatory diagram showing a configuration of a conventional lighting device and a light distribution function thereof.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Main reflector (1st reflection member) 1a ... Main reflection part 1b ... Side reflection part 2 ... Sub-reflector (2nd reflection member) 2a ... Central opening part (slit) 2b ... Both side reflection parts DESCRIPTION OF SYMBOLS 3 ... Xenon tube (illumination element), 3a, 3b ... Terminal, 4 ... Positioning part, 5 ... Rubber band, 6 ... Lead wire, 7 ... Trigger wire, 8 ... Spherical lighting element, 9 ... Transmission part, 10 ... Reflection part .

Claims (3)

[Claims] 1. A first reflecting member for reflecting a light beam of a flash discharge tube to a subject side, and a second reflecting member adjacent to the flash discharge tube and reflecting a light beam from the discharge tube to the first reflecting member side. And a lighting device for a camera. 2. The lighting device according to claim 1, wherein the second reflection member has an opening through which the irradiated light beam passes. A first reflecting member for reflecting a light beam from the flash discharge tube toward a subject; and a reflecting surface adjacent to the flash discharge tube and facing a reflecting surface of the first reflecting member. And a second reflection member having an opening so that a part of the light beam passes therethrough.