JPH0623039U - camera - Google Patents

Abstract

(57) [Summary] [Structure] The camera 1 of the present invention has a photographing optical system 2, distance measuring means for measuring the distance to the subject, photometric means for measuring the luminance of the subject, and strobe means 5. . Between the stroboscopic light emitting body 52 of the stroboscopic device 5 and the Fresnel lens 51, a pair of flat plates 61 and 62 facing each other, and an expandable and contractible connecting member 63 for liquid-tightly connecting the outer peripheral portions of both flat plates,
A variable apex angle prism 6 composed of an optically transparent liquid 64 filled inside these is installed. Based on the distance measurement information obtained by the distance measuring means, the motor 66 is operated to adjust the apex angle of the variable apex angle prism 6, and the strobe light irradiation area of the strobe optical system 50 deviates from the image area of the photographing optical system 2. To correct. [Effect] Strobe light can be efficiently emitted to the entire shooting area regardless of the distance to the subject.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a camera having a flash mechanism such as a strobe.

[0002]

[Prior art]

 2. Description of the Related Art There is known a camera which has a photometric unit and a strobe, and is configured to emit a strobe light when the brightness of an object is measured by the photometric unit and the result is underexposure. In such a camera, a strobe optical system that irradiates the subject with light from a stroboscopic light emitting body, which is a light source, is fixedly installed in the camera, and its optical path is parallel to the optical path of the imaging optical system. Is set.

In this case, since the strobe optical system and the photographing optical system are installed on the camera at a predetermined distance from each other, there is almost no problem when the subject is a long distance, but when the subject is a short distance, A problem (vignetting) occurs between the imaged area of the photographic optical system and the area where the strobe light is irradiated, and the subject is not effectively irradiated with the strobe light, and shooting is performed.

In consideration of such short-distance shooting, it is possible to set a large strobe light irradiation angle (spreading) in advance so as to cover the entire captured image region during short-distance shooting. In this case, since the amount of light emitted to the subject is reduced at the time of medium-range or long-range shooting, the strobe capacity must be increased, which causes a problem of increasing the size of the camera.

[0005]

[Problems to be solved by the device]

 An object of the present invention is to provide a camera that can efficiently irradiate strobe light over the entire captured image area regardless of the distance to the subject.

[0006]

[Means for Solving the Problems]

 Such an object is achieved by the present invention of the following (1) to (4).

(1) A camera having a photographing optical system, distance measuring means for measuring a distance to a subject, and a strobe optical system for irradiating a subject with light from a strobe light emitter, wherein the strobe optical system is provided. Has a variable apex angle prism in which an optically transparent and easily deformable substance is interposed between at least a pair of plates facing each other, and the angle formed by the plates can be changed by a driving means. The angle formed by the both plates of the variable apex angle prism is adjusted based on the distance measurement information obtained by the means, and the optical path of the irradiation light from the stroboscopic optical system with respect to the photographed image area in the photographing optical system is deviated. A camera characterized by correcting the.

(2) The camera according to (1), wherein the drive means operates to change the angle formed by both plates of the variable apex angle prism only when the stroboscopic light-emitter emits light.

(3) In the variable apex angle prism, a pair of plates, an expandable and contractible connecting member that connects the outer peripheral portions of both plates to each other in a liquid-tight manner, and a space surrounded by the both plates and the connecting member are filled. (1) or (2) above, which has a held optically transparent liquid and is configured to displace at least one of the plates by a drive means to change the angle formed by both plates. camera.

(4) The driving means is composed of a motor, a worm gear installed on a rotation shaft of the motor, and a rack installed on an outer edge portion of the plate and meshing with the worm gear. The camera according to any one of (1) to (3) above.

[0011]

【Example】

 Hereinafter, the camera of the present invention will be described in detail with reference to the preferred embodiments shown in the accompanying drawings. FIG. 1 is a front view showing a configuration example when the camera of the present invention is applied to a compact camera, and FIG. 2 is a sectional view taken along line II-II in FIG. As shown in these drawings, the camera 1 is an autofocus (hereinafter referred to as “AF”) camera, and includes a photographing optical system 2, a photometric device 3 including a photometric optical system and a light receiving element, and a finder optical system 4. It has a flash unit 5, a distance measuring unit 7, and a control unit 8. Each of these components will be described below. For convenience of explanation, the left side in FIG. 2 is called the front and the right side is called the rear.

As shown in FIG. 2, the photographic optical system 2 has a configuration in which a lens 21 formed by combining a plurality of lenses and a shutter 22 positioned in front of the lens 21 are installed in a lens barrel 20. ing.

The lens 21 is installed so as to be movable in the direction of the optical axis 25 of the photographing optical system 2, and all or some of the lenses 21 are moved in the direction of the optical axis 25 by an AF motor 10 described later. Focusing is performed. In such focusing, the control unit 8 controls the drive of the AF motor 10 based on the distance measurement information obtained by the distance measurement unit 7 described later, that is, the distance to the subject, and the in-focus state is obtained. By moving the lens as shown. Further, the lens 21 may be configured to allow further zooming.

The shutter 22 has both a shutter function for transmitting and blocking light and a diaphragm function for adjusting the amount of received light (so-called lens shutter). At the time of photographing, the optimum aperture value and shutter speed are determined from the exposure value obtained based on the photometric value obtained by the photometric means 3 described later, and the shutter drive means 11 operates the shutter 22 under this condition. The shutter 22 may be installed between the lenses 21, behind the lens 21, or the like.

A finder optical system 4 is provided above the photographing optical system 2 in the figure with a predetermined distance from the photographing optical system 2. The finder optical system 4 includes a lens 41 formed by combining a plurality of lenses, and an eyepiece (not shown) formed on the back side of the camera body, which is located behind the lens 41. . The optical axis 45 of the finder optical system 4 is set to be parallel to the optical axis 25 of the photographing optical system 2.

When the photographing optical system 2 is capable of zooming, in order to adjust the magnification of the field of view in the finder optical system 4 in accordance with the zooming, the lens 41 includes all or a part of them. However, it can be moved in the direction of the optical axis 45 by a driving means (not shown).

As shown in FIG. 1, a photometric unit 3 is installed at a position separated from the photographing optical system 2 and the finder optical system 4 by a predetermined distance. Although not shown, the photometric unit 3 is mainly composed of a photometric optical system including a lens and a light receiving element that is installed on the rear side of the lens and receives light transmitted through the lens. It In this case, the optical axis 35 of the photometric optical system is set to be parallel to the optical axis 25 of the photographing optical system 2.

The light receiving element photoelectrically converts the received light and outputs a voltage according to the amount of received light, and a photoelectric conversion element such as a silicon photodiode (SPD) is preferably used. Based on the voltage value output from the light receiving element, the exposure calculation is performed by the control means 8 described later. Then, the aperture value and the shutter speed are determined based on the calculated exposure, and the shutter 22 operates under this condition. If the control means 8 determines that the exposure is insufficient, the strobe means 5 to be described later is activated to emit strobe light at the time of photographing.

As the distance measuring unit 7, an infrared active focus position detection mechanism (AF optical block) is used, and as shown in FIG. 1, a light emitting unit 71 including an infrared light emitting element and a collimating lens is provided. , And a light receiving section 72 mainly composed of a position sensitive device (PSD) that receives reflected infrared light from a subject. In this case, the infrared light emitting section 71 and the infrared light receiving section 72 are arranged with a predetermined distance (base line length) therebetween with the finder optical system 4 interposed therebetween.

As shown in FIG. 1, a strobe unit 5 is installed above the photographing optical system 2 and on the side of the light emitting unit 71. The strobe means 5 includes a strobe light emitter 52 connected to a flash circuit 12, which will be described later, a reflector 53 installed around the strobe light emitter 52, and a strobe optical system installed in front of the strobe light emitter 52. 50, and a housing 54 having a light blocking effect and supporting the stroboscopic light emitting body 52 and the reflector 53.

The strobe optical system 50 is composed of a Fresnel lens 51 installed in front of the camera 1 and a variable apex angle prism 6 installed between the Fresnel lens 51 and the stroboscopic light emitter 52. (See Figure 2).

The variable apex angle prism 6 has a pair of flat plates 61 and 62 facing each other. The shapes of the flat plates 61 and 62 include, for example, a circle, an ellipse, and a rectangle. The outer peripheral portions of the flat plates 61 and 62 are liquid-tightly connected to each other by a flexible bellows-shaped connecting member 63 over the entire circumference. An optically transparent liquid 64 is filled in the space surrounded by the flat plates 61 and 62 and the connecting member 63. The constituent materials of the flat plates 61 and 62, the connecting member 63, the type of the liquid 64, and the like will be described later in detail.

In the variable apex angle prism 6 shown in the figure, the flat plate 62 on the rear side (the incident side of the strobe light) is arranged in the housing 54 so as to be perpendicular to the optical axis 55 by a supporting member 65 made of, for example, an elastic material. It is fixed. The flat plate 61 on the front side (strobe light emission side) has one outer edge fixed to the inside of the housing 54 by a similar supporting member 65, and the end opposite to the fixing member has a supporting member. A rack 68 is attached via 65.

On the other hand, a motor 66 which is a driving means for changing the apex angle of the variable apex angle prism 6 is installed in the lower part of the support member 54 in the figure, and the rack 66 is provided at the tip of the rotary shaft of the motor 66. A worm gear 67 that meshes with 68 is installed. The motor 66 can rotate in either forward or reverse directions.

By the rotational driving of the motor 66, the rack 68 moves in the direction of the optical axis 55 in the opening 541 formed in the lower part of the housing 54 in FIG. 2, and accordingly the lower end of the flat plate 61 moves in the same direction. And the flat plate 61 is tilted, and the angle of the flat plate 61 with respect to the flat plate 62 (vertical angle of the prism 6) changes. This causes a prism action, and as shown in FIG. 3, the optical axis 55 ′ in front of the flat plate 61 is bent in the direction of the optical axis 25 of the photographing optical system 2 (rightward in FIG. 3), and the strobe means 5 is moved. The strobe light irradiation area B due to moves by a predetermined amount. The movement direction and the movement amount of the strobe light irradiation area are such as to offset the deviation (parallax) from the image area A in the photographing optical system 2, and preferably the strobe light irradiation area B coincides with the image area A. Alternatively, it is intended to include this.

The structure of the drive means for changing the apex angle of the variable apex angle prism 6 is not limited to the one shown in the figure, which includes the motor 66, the worm gear 67, and the rack 68. A solenoid or actuator whose amount can be adjusted may be used.

The flat plates 61 and 62 may be optically transparent or may have a function as an optical filter such as a UV filter. For example, borosilicate glass (BK-based), crown glass (SK-based), various optical glasses such as SF-based, BaSF-based, LaSF-based, and LaK-based, and other glass (white plate) having the same function as these. Is mentioned.

Examples of the constituent material of the connecting member 63 include natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, nitrile rubber, diene rubber such as chloroprene rubber, ethylene-propylene rubber, and butyl rubber. Various rubber materials such as olefin rubber, ether rubber, polysulfide rubber, urethane rubber, fluorine rubber, silicone rubber, urethane rubber, ester rubber, amide rubber, olefin rubber, styrene rubber, vinyl chloride rubber, An elastic material such as a fluorine-based, ionomer-based, or isoprene-based thermoplastic elastomer, or a mixture (alloy) thereof can be used.

Examples of the liquid 64 include water, alcohols, ethylene glycol, propylene glycol, glycerin, carbon tetrachloride, chloroform, ethylene halide and other halogenated alkyls, formic acid, acetic acid and other organic acids, and methyl acetate. , Esters such as ethyl acetate, ethers, ketones, low molecular weight polyethers, low molecular weight polyesters, organic liquids such as aromatic compounds, viscous liquids such as liquid paraffin, silicone oil and polyvinyl alcohol, or a mixture of two or more of these. Liquids, solutions in which solids are dissolved in these liquids, and the like can be mentioned.

When selecting the constituent materials of the flat plates 61, 62 and the connecting member 63, it is necessary to use a material which is inert (for example, does not dissolve or deteriorate) in the liquid 64 to be used.

FIG. 4 is a block diagram showing the configuration of the camera of the present invention. As shown in the figure, the camera 1 controls AF operation, exposure calculation, drive control of the motor 66, control of the shutter drive means 11, sequence control, display device control, control of the flash circuit 12, drive of the wind motor. It has a control means 8 composed of a microcomputer for controlling and controlling a self-timer. The control means 8 includes the photometry means 3, the distance measurement means 7, the motor 66, the U-θ data table 9, the AF motor 10, the shutter drive means 11, and the flash circuit 12 described below. Are electrically connected.

In the U-θ data table 9, the following data relating the apex angle θ of the variable apex angle prism 6 and the distance U from the imaging optical system 2 to the subject 15 is tabulated and stored. There is. That is, regarding the relationship between the distance U and the apex angle θ, the distance between the photographing optical system 2 and the stroboscopic optical system 50 (the distance between the centers of both optical systems) is L (see FIG. 1), and the variable apex angle prism 6 Assuming that the total refractive index n is 1.5, the angle between the optical axis 55 behind the variable apex angle prism 6 and the optical axis 55 ′ in front of the variable apex angle prism 6 is θ / 2. Become.

[0033]

[Equation 1]

According to this formula, for example, the relationship between the distance U and the apex angle θ in a camera of L = 30 mm is obtained, and a plurality of representative distances U are shown in Table 1 below. For the camera, the results are shown in Table 2 below. The value of L is peculiar to the camera, and the relationship between U and θ at L is the U-θ data table 9.

[0035]

[Table 1]

[0036]

[Table 2]

When the distance to the subject 15 is detected by the distance measuring unit 7 and is input to the control unit 8, when the flash light emission is performed, the control unit 8 accesses the U-θ data table 9 and detects it. Data relating to the distance U that is equal to or close to the calculated distance is selected from the U-θ data table 9 and the θ value is determined from this. Then, the control means 8 controls the rotation direction and the rotation amount of the motor 66 so that the apex angle of the variable apex angle prism 6 becomes this θ value, and adjusts the apex angle of the variable apex angle prism 6.

The AF motor 10 is a drive source for moving the lens 21 of the photographing optical system 2 in the direction of the optical axis 25, and is driven by a signal output from the control means 8 so that a focused state can be obtained. Controlled. The shutter driving means 11 controls the narrowing operation of the shutter 22, controls the opening / closing of the shutter, and the like.

The flash circuit 12 is for charging a power source, supplying electric power to the stroboscopic light emitting body 52, controlling (tuning) the light emission timing of the stroboscopic light emitting body 52, and the like. Further, the flash circuit 12 may have a so-called automatic light adjustment function of automatically adjusting the amount of light emitted from the stroboscopic light emitter 52 in relation to the aperture value and the shutter speed described above.

Hereinafter, an example of a shooting method by the illustrated camera 1 will be described with reference to the flowchart of FIG. As shown in FIG. 5, first, it is judged whether or not the first-step release switch (SW ₁ ) in the two-step release switch is turned on (step 100). Distance measurement is performed, and calculation is further performed by the control means 8 (step 101). If the release switch (SW ₁ ) is not on, after a certain period of time, it is determined again whether or not the release switch (SW ₁ ) is on.

After step 101, photometric means 3 performs photometry, and control means 8 performs exposure calculation (step 102). Based on the result of this calculation, the aperture value and shutter speed are determined, and the presence or absence of strobe light emission is also determined. That is, when the exposure is insufficient, the stroboscopic light emitting body 52 emits light. It is determined whether or not the stroboscopic light emitting body 52 emits light (step 103), and if it does not emit light, the process proceeds to step 107 described later.

When the stroboscopic light emitting body 52 is to emit light, first, the data corresponding to the distance to the subject 15 obtained in step 101 is read from the U-θ data table 9 (step 104) and the variable top is read. The apex angle θ of the angular prism 6 is determined (step 105).

Then, the motor 66 is operated under the control of the control means 8 to set the apex angle of the variable apex angle prism 6 installed in the strobe optical system 50 to the apex angle θ determined above (step 106). . As a result, the direction of the optical path of the irradiation light from the strobe optical system 50 changes, that is, the stroboscopic light irradiation area B moves and coincides with or includes the image area A of the photographing optical system 2, and both optical systems. Parallax of 50 and 2 is corrected. As a result, a sufficient amount of strobe light is applied to the entire image area to be photographed.

Even when the strobe light irradiation area B includes the image area A of the photographing optical system 2, the strobe light irradiation area B does not significantly exceed the image area A (for example, the area ratio A / B = 0.7 to If the irradiation angle (spreading) of the stroboscopic light is adjusted to about 1.0), efficient stroboscopic light irradiation can be performed without increasing the stroboscopic capacity.

After adjusting the apex angle of the variable apex prism 6, the release operation is waited (step 107) and it is determined whether or not the second-stage release switch (SW ₂ ) is turned on. (Step 108). If SW ₂ is not on, the procedure returns to the step 100. When SW ₂ is on, the AF motor 10 is driven to move the lens 21 based on the distance to the subject obtained in step 101, and the in-focus state is obtained (step 109).

After that, the shutter drive means 11 operates the shutter 22 to take an image. (Step 110) Here, when the stroboscopic light emitter 52 emits light as a result of the exposure calculation in step 102, the stroboscopic light emitter 52 emits a desired amount of light in synchronization with the operation of the shutter 22. After shooting, a wind motor (not shown) is driven to wind up the film F (step 111).

In the example shown in FIG. 5, only when the stroboscopic light emitting body 52 emits light, the driving means is operated to adjust the apex angle of the variable apex angle prism 6. Not limited to this, for example, the configuration may be such that the apex angle of the variable apex angle prism 6 is always adjusted regardless of whether or not the stroboscopic light emitting body 52 emits light.

The camera of the present invention has been described above with reference to the illustrated configuration examples, but the present invention is not limited to these. For example, the opposing plates of the variable apex angle prism 6 are not limited to the flat plates described above, and may have a function of a curved plate or a lens.

Further, in the variable apex angle prism, the optically transparent and easily deformable substance interposed between the opposed plates is not limited to the liquid 64, but may be a transparent elastic body such as silicone rubber. May be solid.

In the illustrated configuration example, when adjusting the apex angle of the variable apex angle prism 6, the flat plate 61 on the emission side of the irradiation light is displaced, but the flat plate 62 on the incident side of the irradiation light is deviated. Alternatively, both the flat plates 61 and 62 may be displaced.

Further, in the illustrated configuration example, the apex angle of the variable apex angle prism 6 changes only in one direction, but the present invention is not limited to this, and the apex angle is changed in two orthogonal directions, The strobe irradiation light may be moved in any direction up and down and left and right.

[0052]

[Effect of device]

 As described above, according to the camera of the present invention, it is possible to correct the shift of the strobe light irradiation area of the strobe optical system with respect to the image area of the photographing optical system caused by the change in the distance to the subject. The entire area can be fully illuminated with strobe light, and a more appropriate exposure can be taken.

Further, since these corrections are performed corresponding to the distance to the subject obtained by the distance measuring means, more accurate corrections are possible. Particularly, according to the present invention, it is necessary to separately provide a mechanism for moving the stroboscopic light emitter or the reflecting plate in order to increase the strobe capacity, and to change the strobe light irradiation angle (spreading) and the irradiation direction. Also, the camera does not become large.

[Brief description of drawings]

FIG. 1 is a front view showing a configuration example of a camera of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a plan view schematically showing the camera of the present invention in which one flat plate of the variable apex angle prism is displaced.

FIG. 4 is a block diagram showing a configuration of a camera of the present invention.

FIG. 5 is a flowchart showing an example of a photographing method by the camera of the present invention.

[Explanation of symbols]

 1 camera 2 photographing optical system 20 lens barrel 21 lens 22 shutter 25 optical axis 3 photometric means 35 optical axis 4 viewfinder optical system 41 lens 45 optical axis 5 strobe means 50 strobe optical system 51 Fresnel lens 52 strobe light emitter 53 reflector 54 housing Body 541 Opening 55, 55 'Optical axis 6 Variable vertical angle prism 61, 62 Flat plate 63 Connection member 64 Liquid 65 Support member 66 Motor 67 Worm gear 68 Rack 7 Distance measuring means 71 Light emitting part 72 Light receiving part 8 Control means 9 U-θ data Table 10 AF motor 11 Shutter driving means 12 Flash circuit 15 Subject 100 to 111 Step A Image area of photographing optical system B Strobe light irradiation area F Film

Claims (4)

[Scope of utility model registration request] 1. A camera having a photographing optical system, distance measuring means for measuring a distance to a subject, and a strobe optical system for irradiating the subject with light from a stroboscopic light emitting body, wherein the strobe optical system comprises: An optically transparent and easily deformable substance is interposed between at least a pair of plates facing each other, and a variable apex angle prism capable of changing an angle formed by the plates by a driving unit is provided, and the variable apex prism is provided by the distance measuring unit. Based on the distance measurement information obtained, it is possible to adjust the angle formed by both the plates of the variable apex angle prism to correct the deviation of the optical path of the irradiation light from the strobe optical system with respect to the captured image area in the photographing optical system. Characteristic camera. 2. The camera according to claim 1, wherein only when the stroboscopic light-emitter emits light, the drive means operates to change an angle formed by both plates of the variable apex angle prism. 3. The variable apex angle prism includes a pair of plates,
An expandable and contractible connecting member for connecting the outer peripheral portions of both plates to each other in a liquid-tight manner, and an optically transparent liquid filled in a space surrounded by the both plates and the connecting member, and at least one of them by a driving means. The camera according to claim 1 or 2, wherein the camera is configured to be displaced to change an angle formed by the two plates. 4. The drive means comprises a motor, a worm gear installed on a rotation shaft of the motor, and a rack installed on an outer edge portion of the plate and meshing with the worm gear. The camera according to any one of 1 to 3.