JPH11242267A - Illuminator and photographing device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an illuminator suitable for a still camera and a video camera, etc., capable of illuminating a subject side by luminous flux from a light source means with high illumination efficiency, and a photographing device using the illuminator. SOLUTION: Out of the luminous flux from the light source means 4; the luminous flux radiated to the subject side irradiates the subject side through an optical member 5 and the luminous flux radiated to an opposite side to the subject side is reflected by a reflection means and then irradiates the subject side through the member 5 in this illuminator. In such a case, the member 5 has an incident surface 5a opposed to the light source means 4, a reflection surface partially or totally reflecting the luminous flux from the incident surface 5a, and an emitting surface 5b opposed to the incident surface 5a. The reflection means has a light emitting end face projecting toward the subject side, and one part of the light emitting end face is constituted of a shape part positioned near to the subject side from the incident surface 5a of the member 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device and a photographing device using the same, for example, a camera body (photographing body).
It is suitable for efficiently illuminating the subject side with illumination light (flash light) in conjunction with the photographing operation of the camera body and photographing, by attaching to a part of the camera body.

[0002]

2. Description of the Related Art Heretofore, there have been various illumination devices (strobe devices) which are attached to a part of a camera body and irradiate illumination light (flash light) to a subject side in synchronization with a photographing operation of the camera to photograph. It has been proposed.

For example, in Japanese Utility Model Laid-Open Publication No. 57-150826, the light emitting unit is held and fixed at a position away from the optical axis of the camera when used, and the light emitting unit falls down to the front side when not in use to form a shape integral with the camera. There has been proposed a lighting device configured to be such that:

In Japanese Patent Application Laid-Open No. 59-165037, a predetermined light distribution is obtained by converging a light beam emitted from a flash discharge tube into a band shape, arranging a fiber at the condensing portion, and bundling the fibers appropriately. There has been proposed a lighting device configured to be able to be used.

In Japanese Patent Application Laid-Open No. 8-234277, the present applicant discloses a light-emitting means and guides light from the light-emitting means to a subject in a longitudinal direction of the member through a member. Optical means for converging and radiating light toward the object, guiding the light from the light emitting means through the member in the longitudinal direction of the member, and condensing and radiating the light toward the subject. The device is proposed.

FIG. 6 is a schematic cross-sectional view of the vicinity of a light emitting portion of a lighting device using a conventional light guide member (also referred to as an optical member, an optical panel, and a light guide). In FIG. 6, a light-emitting portion has a cylindrical flash light-emitting tube 4 that emits flash light, and light emitted from the flash light-emitting tube 4 is made incident on an incident surface 5a, guided in the longitudinal direction, condensed, and emitted from an emission surface 5b. The light-guiding member 5 includes a light-guiding member 5 and a reflecting mirror 6 that efficiently guides the light emitted from the flash light-emitting tube 4 to the incident surface 5a so as not to escape as far as possible outside a necessary range.

In the above configuration, the light distribution in the left-right direction is relatively easily adjusted by changing the curvature of the exit surface 5b of the light guide member 5. The light distribution in the vertical direction is performed by the light guide member 5.
By changing the thickness between the light entrance surface 5a and the light exit surface 5b to change the reflection angles of the upper and lower reflection surfaces of the light guide member 5, or change the distance between the flash arc tube 4 and the light entrance surface of the light guide member 5. It is adjusted by letting it do. In order to efficiently guide the light from the flash tube 4 to the light guide member 5, as described later, it is advantageous to make the interval between the flash tube 4 and the light guide member 5 as small as possible. By narrowing even the light guide member, it is possible to widen the light distribution angle in the vertical direction.

[0008]

Generally, an illumination device (a strobe device) to be mounted on a photographing device in which the entire device such as a camera is miniaturized and reduced in weight is (a1).

(A2) The illumination light from the light source means can be efficiently radiated to the subject side.

(A3). The lighting device must be safe without heat. Are required.

In the lighting device shown in FIG.
Depending on the positional relationship between the light source and the reflecting mirror 6 and the light source 4, the light guide member cannot efficiently take the direct light and the reflected light from the light source at the incident surface 5a of the light guide member 5, and In some cases, the emitted light cannot be efficiently guided forward.

In addition, the light emitting section is provided between the flash light emitting tube 4 and the light guiding member 5 so that the light guiding member 5 is not affected by heat (burn, deformation, etc.) because the temperature of the flash light emitting tube 4 becomes high during light emission. It is necessary to leave a gap with the light incident surface 5a, and a gap A1 'is opened between the light guide member 5 and the reflecting mirror 6 so that heat does not stay near the light emitting portion. However, the effective light flux may escape from the gap A ′, and as a result,
This is a factor that lowers the efficiency of the light emitting unit and makes it impossible to increase the light distribution angle in the vertical direction.

Further, since a gap is formed in the light emitting direction, the length of the light emitting portion is extended by the gap, which is a disadvantageous factor for downsizing.

Particularly in recent years, the size of cameras has been reduced,
Conventionally, the main purpose of this type of light emitting unit is to reduce its size, but if it emits light continuously, heat will be trapped in the vicinity of the light emission, and the members near the light emitting unit will become hot, and the light emitting unit itself will be damaged by heat and burn Therefore, there is a problem that it is difficult to reduce the size unless heat measures such as heat radiation are taken.

According to the present invention, heat generated from a light-emitting light source can be efficiently dissipated by appropriately configuring a light-guiding member (optical member) for guiding light from a light source means and a reflecting mirror. In this way, the gap between the light emitting source and the light incident surface of the light guide member is reduced, preventing deformation and burning of the light guide member due to heat, and preventing the lighting device itself from becoming overheated. An object of the present invention is to provide a high-performance and safe lighting device and a photographing device using the same by guiding light forward.

[0016]

According to the illumination device of the present invention, (1-1) of the light beams from the light source means, the light beam emitted to the object side is emitted to the side opposite to the object side via the optical member. In a lighting device that irradiates the subject side via the optical member after the light beam is reflected by the reflecting means, the optical member reflects an incident surface facing the light source means, a part of the light beam from the incident surface or and The reflecting means has a reflecting surface for total reflection, an emitting surface facing the incident surface, and the reflecting means has a light emitting end surface protruding in a subject side direction, and the light emitting end surface has a part thereof. It is characterized in that the optical member has a shape located on the object side of the incident surface of the optical member.

In particular, (1-1-1) the reflecting surfaces are upper and lower surfaces and side surfaces with respect to a traveling direction of a light beam of the optical member.

(1-1-2) The light emitting end face has a shape extending toward the subject along upper and lower surfaces of the optical member.

(1-1-3) When the optical member is slid from the subject side of the light source means and is mounted in the case, the optical member is guided by a guide portion provided in the case, and a member for preventing vibration. Have a joint. And so on.

The photographing apparatus of the present invention illuminates a subject by using the illumination device having the structure (2-1),
It is characterized by shooting.

[0021]

FIG. 1 is a schematic view of a main part of a first embodiment in which an illuminating device according to the present invention is provided on an upper side of a camera (imaging device) main body. FIGS. It is the principal part schematic of a part of.

In FIG. 1, reference numeral 1 denotes a camera body (photographing body), and 2 denotes a lens barrel, which holds a photographing lens. Hereinafter, the vertical direction of the camera body 1 is the Y axis, the horizontal direction is the X axis,
The optical axis direction is represented as the Z axis.

Reference numeral 3 denotes a lighting device (light emitting unit).
The camera body 1 is slidably provided in the upper right portion of the camera body 1 in the left-right direction (X direction) or the up-down direction (Y direction).
The illuminating device 3 includes a cylindrical flash discharge tube (flash tube, strobe) 4 that emits flash light as light source means (light emitting means),
Among the luminous fluxes emitted from the flash discharge tube 4, a luminous flux radiated in a direction other than the front, for example, backward (in a direction opposite to the subject side) has a curvature in a one-dimensional direction in which the luminous flux is condensed and reflected toward the subject side, and internal reflection is used. Of the reflected light (reflecting umbrella) 6, the light beam directly incident from the flash discharge tube 4 and the light beam reflected and incident by the reflecting mirror 6 as a light beam having a predetermined shape, and efficiently irradiate the object side with the illumination light beam. (Hereinafter, also referred to as “light guide member”) 5. Reference numeral 6a denotes a light exit end surface, a part of which has a shape located closer to a subject than the incident surface 5a of the optical member 5. The light emitting end face 6a is composed of a protruding member continuous from the reflecting mirror 6. The reflecting mirror 6 and the light emitting end face 6a constitute one element of the reflecting means.

The optical member 5 is a flat transparent member (glass,
Plastic). The optical member 5 includes an incident surface 5a and a light incident surface 5a on which a light beam from the flash discharge tube 4 is incident.
the upper and lower surfaces 5c as a reflection surface for totally reflecting the light beam from a (5c _1, 5c ₂₎ and the side surface 5d (5d _1, 5d
₂ ) and a light beam directly guided from the incident surface 5a, and an emission surface 5b that is totally reflected by the upper and lower surfaces 5c and the side surfaces 5d or emits a light beam guided after repeated total reflection to the subject side. have.

The area between the entrance surface 5a and the exit surface 5b is a light guide. The entrance surface 5a and the exit surface 5b are arranged to face each other. That is, the entrance surface and the exit surface are arranged on a line extending in the optical axis direction of the taking lens. The entrance surface 5a and the exit surface 5b are flat surfaces or curved surfaces having a positive or negative refractive power having a curvature (in the present specification, the curved surface is a spherical surface, an aspherical surface, an elliptical surface, a quadratic curved surface, a cylindrical surface, a toric surface, or the like). ).

It is to be noted that a part of the entrance surface 5a and / or the exit surface 5b may be a curved surface, and the other part may be a flat surface.

In FIG. 2, the flash tube 4 and the reflecting mirror 6 are brought into contact with the projections 8c of the elastic bush case 8 inserted at both ends of the flash tube 4 so that the reflecting mirror 6 is attached to the wall 8a of the case 8. Energized and fixed.

In FIG. 2, the light incident surface 5a of the light guide member 5
Is made closer to the flash tube 4 from the light emitting end face 6a of the reflecting mirror 6 to reduce the gap between the light guiding member 5 and the reflecting mirror 6, thereby allowing light to enter the light guiding member 5 other than the light incident surface 5a. Leakage is prevented as much as possible to improve light use efficiency.

Compared with this embodiment and the conventional illuminating device shown in FIG. 6, the gap between the light exit end face 6a of the reflecting mirror 6 and the light incident surface 5a of the light guide member 5 in this embodiment is shown in FIG. As shown in (5), since the light exit end face 6a of the reflecting mirror 6 and the light incident face 5a of the light guide member 5 overlap each other by the length A1, there is no gap. Also, the gaps B1 and B2 in the vertical direction are reduced as much as possible by bringing the reflecting mirror 6 and the light guide member 5 closer to each other.

Further, by bringing the light incident surface 5a of the light guide member 5 close to the flash arc tube 4, the light incident surface 5a of the light guide member 5 is formed.
The angle of incidence of light incident on the can be widened, and even if the light guide member has the same shape, the loss of the incident light is minimized,
The light distribution angle can be expanded in the vertical direction.

In FIG. 3, the entrance surface 5a and the exit surface 5b of the optical member 5 are shown as planes for simplicity. Upper and lower surface 5
The c ₁ , 5c ₂ and the side surfaces 5d ₁ , 5d ₂ are formed of flat or curved surfaces that spread at a large angle with respect to the incident surface 5a.

The optical member 5 has such a shape that the exit area of the exit surface 5b is larger than the entrance area of the entrance surface 5a. For example, the optical member 5 has side surfaces 5d ₁ , 5d ₂ from the entrance surface 5a to the exit surface 5b in the XY section.
And / or the distance between the upper and lower surfaces 5c ₁ and 5c ₂ increases sequentially or at a constant rate.

More specifically, a light guide section whose XY sectional area increases at a constant rate or in a higher-order function is provided.

In this embodiment, the illumination device 3 may be mounted on the side surface of the camera body 1 so as to be slidable in the vertical direction (Y-axis direction) or the left-right direction (X-axis direction).

In the illumination device of the present embodiment, the light beam emitted from the flash discharge tube 4 is guided to the incident surface 5a of the optical member 5 directly or after being reflected by the reflecting mirror 6. Part of the light beam incident on the incident surface 5a goes straight and is guided to the exit surface 5b,
The other part is totally reflected by the upper and lower surfaces 5c and / or the side surfaces 5d and is guided to the emission surface 5b.

By repeating total reflection on the inner surface of the optical member 5 as described above, an illumination light beam having a high condensing property is formed on the object side from the exit surface 5b in a predetermined illumination light beam shape (for example, square in the XY cross section, in the X-axis direction). (E.g., a long rectangle).

In particular, of the luminous flux of the flash discharge tube, the luminous flux in the radial direction (Y direction) is repeatedly totally reflected by the upper and lower surfaces 5c ₁ and 5c ₂ , and the luminous flux in the axial direction (X direction) is refracted by the curved surface of the exit surface 5d. And efficiently irradiate the light to the subject side.

Next, the optical member 5 for guiding the illumination light beam according to the present invention will be described. FIG. 2 is a sectional view of an essential part when the optical member for guiding the illumination light beam according to the present invention is constituted by a flat light guide. The optical member 5 has a polygonal (for example, a quadrilateral) incident surface (light incident surface) formed of a flat surface or a curved surface.
5a, a plane (e.g., a quadrilateral) exit surface (light exit surface) 5b composed of a plane or a curved surface having an area larger than the entrance surface 5a, a plane having a constant inclination from the entrance surface 5a to the exit surface 5b, or Upper and lower surfaces 5c ₁ , 5c ₂ composed of curved surfaces,
Side surfaces 5d ₁ and 5d ₂ (side surfaces 5d ₁ and 5d ₂ are not shown)
And has a flat plate shape such as a polygonal frustum (frustum of a quadrangular pyramid).

Incidentally, the entrance surface 5a and the exit surface 5b are represented by planes for simplicity. The flash discharge tube (not shown) has an entrance surface 5
It is arranged at a position separated by a predetermined distance from a. _Vd is the height of the entrance surface 5a (vertical direction when mounted on the camera body, Y direction), A is the center (center) in the height direction (Y direction) of the entrance surface 5a, and _Ve is the exit surface 5b. , B is the center (center) of the exit surface 5b in the height direction, and L is the length of the optical member 5 (the length in the Z-axis direction). L _AB is a straight line connecting point A and point B (hereinafter referred to as “optical axis” or “irradiation optical axis”), L _C
Is an axis passing through the end C of the exit surface 5b and parallel to the optical axis L _AB .

[0040] Next state in the present embodiment is disposed a uniform diffuse light source for each angular component to the front surface of the light incident surface 5a, i.e., each angle component at all points of the height V _d of the light incident surface 5a Maximum incident angle α with uniform intensity (uniform light distribution)
A description will be given of the state of travel of the light beam when the light is incident on the light incident surface 5a.

In this case, each point 5a ₁ , 5a on the light incident surface 5a
Small components of the incident angle of the light beam incident from a ₂ is go straight as shown in the figure, emitted from the light emission face 5b. On the other hand, a component having a large incident angle is totally reflected a predetermined number of times on the surfaces 5c ₁ and 5c ₂ of the optical member 7 in accordance with the magnitude of the incident angle, and then exits from the light exit surface 5b. The illustrated example shows a case where total reflection is performed up to three times and emitted. This will be described with reference to the ray tracing diagram shown in the figure.

The ray tracing diagram shows the central portion B on the light exit surface 5b.
Pass through. The maximum angle of each total reflection component is indicated by a thin line. Each of the light beams m _{2 to} m ₂ ′ indicates the number of reflections of the suffix, and the upper and lower light beams when the suffix is emitted from the emission surface 5b with or without the dash. For example, m ₂ means the maximum value of the upper angle component at the twice reflection point B, and m ₀ ′
Indicates the maximum value on the lower side of the direct light emitted from the emission surface 5b without being totally reflected.

In this case, the maximum exit angle (half angle of view) at the central portion B is β _b , and the point 5a at the upper end of the light incident surface 5a
_It can be seen that the light beam from ₁ is totally reflected twice and then emitted from the central portion B of the light emitting surface 5b.

On the other hand, each ray of light having the maximum angle of each total reflection component passing through the point C at the end of the light exit surface 7b indicated by a two-dot chain line is n ₃ 'to n ₂ . In this case, there is a maximum of two total reflections on the upper side, and a maximum of three total reflections on the lower side.

The maximum emission angle at the point C is β _C0 away from the optical axis and β _{Ci in a} direction approaching the optical axis, and is a component corresponding to the maximum number of total reflections, where β _C0 is the light emission surface. 5b is the maximum emission angle component emitted from 5b.

There is a relationship of β _C0 > β _b > β _Ci between the above numerical values. Although shown for two points in the central portion B and the end point C of the light exit surface 5b in the above example, the points in between become properties of the intermediate, outer than an end point C (the axis L _C
The maximum value β of the exit angle toward (outward of the optical member 5)
_C0 tends to decrease, and the maximum angle β _Ci toward the optical axis tends to increase. Also, comparing the maximum value before and after the angle of incidence of the light beam on the optical member 5 and the exit angle, the maximum value β _C0 at the time of emission is extremely smaller than the maximum value α at the time of incidence.

In this embodiment, as described above, the flash arc tube 4
And the light incident surface 5a of the light guide member 5 are brought close to each other, whereby the maximum incident angle α is increased to widen the light distribution angle.
Further, a light beam having an angle larger than the maximum incident angle α becomes useless light that hardly irradiates the subject as it is, and is advantageous in terms of efficiency in terms of efficiency.

In this embodiment, when light having a uniform light distribution is incident on the incident surface 5a through the optical member 5, the light beam emitted from the exit surface 5b is narrowed down. The distribution is also substantially symmetric about the optical axis L _AB at the center, but the center of the distribution gradually moves outward toward the periphery, and the distribution is most outward at the ends. Then, the maximum value β _C0 at the end is the maximum emission angle via the optical member 5.

Further, even when a light beam having a non-uniform (uneven) light intensity distribution enters the light incident surface 5a, the light distribution unevenness is gradually reduced by repeating total reflection on the upper and lower surfaces and / or the side surfaces. Then, the light is emitted from the emission surface 5b. This is because the incident light is reflected by the total reflection surfaces (upper and lower surfaces, side surfaces) inclined at a predetermined angle, and the angle components are not preserved but are synthesized by being shifted by the inclination angle.

FIG. 4 shows a sketch of the light emitting unit of the lighting device of the present invention. In the drawing, 8 is a case for holding the whole unit, 9 is a lid, 10 is a panel for protecting the front of the light emitting unit, 11 is a flash tube 4 and a reflecting mirror 6.
This is an elastic band for fixing.

In FIG. 4, first, the flash tube 4 and the reflecting mirror 6 are fixed with the band 11, the band 11 is hooked on the rib 8a of the case 8, and the reflecting mirror 6 and the flash tube 4 are brought into close contact with each other by the tension. Next, the light guide member 5 is slid from the front of the flash arc tube 4, and a protrusion (engaging portion) 5 on the lower surface of the light guide member 5 is inserted into a groove (guide portion) (not shown) on the lower surface of the case 8 in the left-right direction.
The vibration is corrected by adjusting the position e, and a positioning dowel (not shown) provided on the upper surface of the light guide member 5 is inserted into the square hole 8b on the upper surface of the case 8 in the front-rear direction. By adopting such a configuration, the light emitting end face 6a of the reflecting mirror 6 and the light incident face 5a of the light guide member 5 are easily overlapped and assembled without increasing the number of components.

FIG. 5 is a schematic view of a main part of a lighting device according to a second embodiment of the present invention. The reflecting means of the present embodiment is different from the reflecting means of FIG.
It protrudes greatly in the direction of the light emitting surface 5b along c ₁ and 5c ₂ , and the surface area and volume of the reflection means are increased.
In this case, if only the reflected light is efficiently transmitted to the light guide member 5, the form of the reflecting mirror in FIG. 2 is sufficient.

However, in the present embodiment, when light is emitted, heat is trapped between the light incident surface 5a of the light guide member 5 and the reflecting mirror 6, and when light is emitted continuously, heat hardly escapes to other parts. Members near the light incident surface 5a and the light emitting portion of the light guide member 5 are easily affected by burns and deformation due to high heat.

Also, the temperature of the outer case near the light emitting portion becomes high, and there is a concern that the burn may cause an effect on the human body. In the form of the light emitting end face 6a of the reflecting means in FIG. 5, since the surface area of the reflecting means is increased, the heat dissipation area of the reflecting means is increased and the heat capacity is also increased. Disperses heat throughout the light-emitting unit, preventing only the light-emitting unit from becoming hot near the light-emitting unit, preventing burns and deformation, etc., and people touching the exterior near the light-emitting unit to feel burns and discomfort due to heat I try not to.

[0055]

According to the present invention, as described above, by appropriately configuring the shape of the light guide member (optical member) for guiding the light from the light source means and the shape of the reflecting mirror, the light emitted from the light emitting light source can be obtained. By efficiently dissipating the heat generated, the gap between the light emitting source and the light incident surface of the light guide member is reduced, preventing deformation and burning of the light guide member due to heat, and preventing the lighting device itself from becoming overheated By efficiently guiding the light from the light emitting source forward, a high-performance and safe lighting device and a photographing device using the same can be achieved.

In particular, according to the present invention, the light incident surface of the light guide member and the light exit end surface of the reflection means are disposed so as to overlap with each other in the direction of the subject, and the light incidence surface of the light guide member is disposed on the reflection means. By approaching the flash arc tube from the light emitting end face,
The gap between the light guide member and the reflecting mirror can be reduced, and light leakage to other than the light incident surface of the light guide member can be prevented as much as possible, thereby improving efficiency.

Further, by bringing the light incident surface of the light guide member closer to the flash tube, it is possible to increase the incident angle of light incident on the light incident surface of the light guide member, and to increase the vertical thickness of the light guide member. It is possible to widen the light distribution angle in the vertical direction without changing the angle.

Further, by extending the light emitting end face of the reflecting means in the light emitting direction, the heat capacity of the reflecting means is increased, and the heat radiation area is widened, so that the heat from the light emitting light source is transmitted to the entire unit, so that the heat is emitted. However, the temperature rises depending on the specific part of the unit, and it is possible to avoid the destruction of the light emitting device due to the high temperature and the adverse effect on the human body such as burns.

Further, by incorporating the light guide member from the front of the light emitting member, the light emitting end face of the reflecting means and the light incident face of the light guide member can be easily overlapped and assembled without increasing the number of parts. The effect of being able to do is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a first embodiment of the present invention.

FIG. 2 is an explanatory view of the lighting device of FIG. 1;

FIG. 3 is an explanatory view of an optical member used in the lighting device of FIG. 1;

FIG. 4 is an explanatory view of the lighting device of FIG. 1;

FIG. 5 is a schematic diagram of a main part of a lighting device according to a second embodiment of the present invention.

FIG. 6 is an explanatory view of a part of a conventional lighting device.

[Explanation of symbols]

1 camera body 2 a lens barrel 3 illumination device 4 light source means (flash discharge tube, the flash light emitting tube) 5 optical member (light guide member) 5a entrance surface 5b exit surface 5c ₁ top 5c ₂ lower surface 5d _1, 5d ₂ side 6 reflected Mirror 6a Light emitting end face 8 case

Claims (5)

[Claims] 1. A light beam emitted from a light source means, which is emitted to a subject side, passes through an optical member, and a light beam emitted to a side opposite to the subject side is reflected by a reflection means, and then reflected by the subject through the optical member. In the illumination device for illuminating the side, the optical member includes an incident surface facing the light source means, a reflecting surface that reflects or partially reflects a part of the light beam from the incident surface, and an exit surface that faces the incident surface. The reflecting means has a light exit end face protruding in the direction toward the subject, and the light exit end face has a shape in which a part thereof is located closer to the subject side than the incidence face of the optical member. A lighting device, comprising: 2. The illuminating device according to claim 1, wherein the reflecting surface is an upper surface, a lower surface, and a side surface with respect to a traveling direction of a light beam of the optical member. 3. The illuminating device according to claim 1, wherein the light exit end surface has a shape extending toward an object along upper and lower surfaces of the optical member. 4. The optical member, when slid from the object side of the light source means and mounted in a case, is guided by a guide portion provided in the case and has an engagement portion for preventing shake. The lighting device according to claim 1, 2 or 3, wherein 5. An imaging device comprising the illumination device according to claim 1. Description: