JP2000347246A - Finder and camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a finder capable of realizing self-portrait photographing. SOLUTION: The lens 32 of the objective lens group 30 of a finder 6 has a surface convex to an object side. A half mirror 33 is formed on this convex surface. This finder is made to satisfy conditions that a field rate at the time of observing a reflected image on a half mirror 33 at the distance of 50 cm from the object side may be >=70% and <=85% with respect to the longitudinal direction of a photographic image plane and that the field rate in the case of observing it with a single eye may be >=70% and <=85% with respect to the lateral direction of the photographic image plane or that the field rate in the case of observing it with both eyes while setting pupil distance as 60 mm may be >=80% and <=100% as a finder for self-portrait, and an appropriate range is observed with respect to the photographic image plane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a viewfinder and a camera capable of self-portrait photography.

[0002]

2. Description of the Related Art At present, a great number of types of cameras for photographing are sold according to applications and functions, and recently, a single-use type camera that allows easy photography. A film unit with a lens is sold by the present applicant as a camera of (1). A film unit with a lens is a unit body that incorporates a photographic mechanism such as a photographic lens and a shutter device and has a built-in unexposed photographic film in advance. Because of the simplicity that it can be sent directly to a developing dealer, it is widely used in general.

[0003] Recently, the number of users performing self-portrait photographing, in which the photographing lens is directed toward the photographer himself, to photograph the photographer himself, has increased. When performing self-portrait shooting, in order to take the photographer himself as a subject, for example, a convex reflecting mirror is arranged on the front of the camera,
The photographer needs to be able to observe the photographer himself.

As a method of arranging a convex reflecting mirror,
Self-portrait photography, adapter method of attaching an adapter with a reflector to the camera for self-portrait photography, sticking a reflective sticker with aluminum vapor deposition on the front of the camera body, for example, around the taking lens, self-portrait photography There is known a switching movement method in which a reflecting mirror is moved to the front of the finder in conjunction with a switching operation of the finder.

[0005]

However, in the above-described adapter system, the mounting of the adapter is troublesome, and there is a high possibility that the adapter is lost. The seal sticking method can be realized at low cost, but it has the disadvantage that the opening that exposes the taking lens in the center of the reflective surface makes it difficult to observe the photographer as the subject, and the reflective seal has the shape of the front surface of the camera body. Therefore, there is a problem that the object (photographer) is distorted and cannot be observed correctly.
In addition, this sticking method imposes restrictions on the design of the camera if the subject can be observed correctly. Further, the switching movement method requires a space for storing the reflecting mirror when the self-portrait photographing is not performed, and thus has the disadvantage that the camera body becomes large and the number of parts increases.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has a self-port which is inexpensive, has little distortion of a reflected image, has no possibility of being lost, and is advantageous in miniaturizing a camera body. It is an object of the present invention to provide a finder that can be used as a rate finder and a camera provided with the finder.

[0007]

According to a first aspect of the present invention, there is provided a finder comprising: an objective lens group having at least one convex surface on the object side; an eyepiece;
A half mirror formed on the convex surface and having a convex surface on the object side, and a reflection image on the half mirror at a distance of 50 cm from the forefront of the objective lens group to the object side as a self-portrait finder. When viewed with a single eye, the field of view in the vertical direction and the horizontal direction of the photographing screen are each 85% or less. Also,
In the finder according to the second aspect, as a finder for a self-portrait, 5 mm from the forefront of the objective lens group to the object side.
The reflected image on the half mirror is observed with both eyes at a distance of 0 cm, and when the interpupillary distance is 60 mm, the field of view of the photographing screen in the interpupillary direction is 100% or less.

According to a third aspect of the present invention, in the finder, the half mirror has a transmittance of light of a single wavelength in a wavelength range of 400 nm to 700 nm of 20% or more and 75% or less. In the finder, the half mirror has a transmittance of 35% or more and 65% or less for light of a single wavelength in a wavelength range of 400 nm to 700 nm. In the finder according to the fifth aspect, the finder magnification is set to 0.45 times or more.

According to a sixth aspect of the present invention, the camera includes the above-described finder and is inserted into a position covering a part of the half mirror on the object side with respect to the half mirror when the mode is switched to the self-portrait mode. And a correction mask for correcting parallax so that the center of the reflected image coincides with the center of the range of the reflection image observed on the half mirror.

The camera according to the present invention has the above-mentioned finder, and when the mode is switched to the self-portrait mode, the camera is inserted into the back side of the half mirror and cuts off from external light entering from the eyepiece side. A light shielding plate for shielding the mirror is provided.

In the present invention, at least one convex surface is provided on the object side.
The objective lens group of the finder is configured to have a surface, and by forming a half mirror that becomes a convex surface on the object side on the convex surface of this objective lens group, as a normal transparent viewfinder by observing the finder from the eyepiece side At the time of self-portrait photography in which the photographer himself is photographed as a subject, the reflected image of the photographer on the half mirror can be observed and used as a self-portrait finder.

In addition, when the reflection image on the half mirror is observed with a single eye from a distance of 50 cm toward the object side, the field of view in the vertical direction and the horizontal direction of the photographing screen is 85% or less, respectively, so that It is possible to observe an appropriate range of the reflected image in consideration of the influence of parallax during portrait shooting. In addition, the interpupillary distance is 6
By satisfying the condition that the visual field ratio in the interpupillary direction is 100% or less when observing with both eyes at 0 mm, it is possible to observe an appropriate range of the reflected image even when observing with both eyes.

When the camera is in an upright posture, for example, when a release button is provided on the upper surface of the camera,
The vertical direction when the release button is naturally held such that a finger is put on the release button with the upper surface facing upward is the vertical direction of the shooting screen, and the horizontal direction is the horizontal direction.

As is well known, the field of view of the finder represents the ratio of the range observed by the finder to the size of the photographing screen. When the field of view exceeds 100%, the photographer observes the field of view. There is a problem that part of the range is not photographed. As in the case of normal photographing through the viewfinder through the eyepiece window, it is desirable that the field of view is close to 100% even when performing self-portrait photographing. However, unlike when looking through the viewfinder through the eyepiece window, when observing the reflected image on the half mirror, the positional relationship between the viewfinder and the photographer is not fixed. Even in the case where parallax occurs, the occurrence of parallax cannot be avoided due to the positional relationship between the finder and the photographer (subject). Specifically, when the photographer observes the reflected image on the half mirror and performs self-portrait photographing, the distance from the front of the finder to the photographer and the eyes of the photographer observing the optical axis of the finder. The amount of parallax generated varies depending on the amount of positional deviation.

It is difficult to make the field of view smaller than necessary, and the photographed subject (photographer) image becomes smaller. However, when the field of view is made lower, the parallax size becomes larger. Even if there is some fluctuation, the range observed on the half mirror can be reliably contained within the screen of the photographed frame on the photographic film, for example. It is also possible to print only the area that has been changed. However, when the field of view is set high, there is a high possibility that a part of the range observed on the half mirror will not fit within the screen of the photographed frame. There is a possibility that an irreparable situation in which a part of the shot area has not been photographed may occur.

For this reason, in order to ensure that only the reflected image of the subject (photographer) included in the photographing range is observed on the half mirror, it is necessary to use the self-portrait viewfinder. The field ratio is set as described above. When observing the reflected image on the half mirror with both eyes, the observed range is slightly wider in the interpupillary direction than in the case of a single eye, but even in such a case, the field rate is 100%. Must not be exceeded.

[0017] The half mirror is used to control the wavelength within the visible light wavelength range.
By setting the transmittance of light having a single wavelength from 00 nm to 700 nm to be 20% or more and 75% or less,
The brightness of the subject image observed through the eyepiece and the brightness of the reflected image observed on the half mirror can be well balanced. If the transmittance exceeds the upper limit of the above range, the reflected image on the half mirror becomes dark, and it becomes difficult for the photographer to observe the reflected image on the half mirror from the object side during self-portrait shooting. Conversely, when the transmittance is below the lower limit of the above range, the subject image observed through the eyepiece becomes dark, and it becomes difficult to observe the subject image. Further, the transmittance of the half mirror for a light beam having a single wavelength of 400 nm to 700 nm is set to 35% to 65%.
The following can achieve a better balance.

When the finder field range as a transparent finder is defined by a field frame provided near the objective lens group, the aperture diameter of the lens constituting the objective lens group increases as the finder magnification increases. That is, the size of the half mirror can be increased. When the field ratio when observing the reflected image on the half mirror from the object side is fixed, the larger the size of the half mirror, the larger the reflected image can be observed, and framing becomes easier.

As a perspective type finder of a photographing lens having a standard photographing angle of view, the finder magnification is usually set to "1" or less. At this time, as the finder magnification approaches "1", the lenses of the objective lens group become closer. Also, since the power of the eyepiece is weakened, the degree of freedom in selecting the radius of curvature of the lens surface is increased. That is, this makes it possible to freely select the radius of curvature of the half mirror without increasing the finder magnification without sacrificing the performance as a see-through finder. The degree of freedom of the radius of curvature makes it easy to adjust the field ratios when used as a perspective finder and when used as a self-portrait finder, and can achieve a target field ratio.

Specifically, the field of view as a self-portrait finder is reduced by bringing the half mirror closer to a plane, and the field of view as a self-portrait finder is reduced by reducing the radius of curvature of the half mirror. Adjustment such as enlargement can be easily performed. Of course, it is easy to adjust each field ratio even when the field of view when used as a see-through viewfinder and a self-portrait viewfinder is defined by the same field frame provided near the objective lens group. For this reason, the viewfinder magnification should be set as high as possible.
It is preferably 0.45 times or more.

When switching to the self-portrait mode, a correction mask is inserted at a position covering a part of the half mirror on the object side with respect to the half mirror, so that the reflection on the center of the photographing screen and the half mirror can be observed. Parallax can be corrected by matching the center of the image range. Using the viewfinder as a see-through viewfinder, parallax when performing close-up shooting with a short shooting distance, and when performing self-portrait shooting at the same shooting distance as this close-up shooting, the eyes of the photographer (subject) It is equivalent to parallax that occurs when placed on the optical axis. Therefore, if the correction mask is inserted closer to the object than the half mirror to perform parallax correction, the correction mask can be used as a correction mask for parallax correction when used as a perspective finder.

Further, when the mode is switched to the self-portrait mode, by inserting the light shielding plate on the back side of the half mirror, external light incident from the eyepiece side is incident on the half mirror and transmitted to the object side. Can be prevented,
The visibility of the reflected image is improved. The position where the light-shielding plate is inserted may be a position where external light from the eyepiece side does not enter the half mirror, and may be behind the lens on which the half mirror is formed, the front surface of the eyepiece, or the eyepiece. It may be between the exposed eyepiece windows.

[0023]

FIG. 2 shows an appearance of a film unit with a lens according to the present invention. This film unit with a lens is a one-time-use camera in which a film cartridge is loaded at the time of manufacturing, and focuses on a subject at a shooting distance of, for example, 3 m, and focuses on a range from approximately 1 m to infinity. The normal shooting mode that focuses on the subject, the close-up shooting mode that focuses on the subject at a shooting distance of 50 cm, and focuses around 50 cm, and the close-up shooting mode that focuses on the subject Same as above, but the photographing mode can be switched from a front side of the film unit with the lens to a self photographing mode (self portrait mode) for photographing the photographer himself as a subject. .

The film unit with a lens comprises a unit main body 3 in which various photographing mechanisms are incorporated, and an exterior paper 4 partially covering the unit main body 3. On the front surface of the unit body 3, a lens barrel 5, an object side window 6 a of a finder 6,
A strobe light emitting unit 7, a strobe operation member 8 for switching the presence or absence of strobe light emission, and a mode switching lever 9 for switching a shooting mode are provided. The lens barrel 5 holds a taking lens 10.

A release button 11 and a counter window 1 for displaying the remaining number of recordable images are provided on the upper surface of the unit body 3.
2, an opening 14 from which a display light guide 13 for indicating completion of flash charging is protruded is provided. further,
On the back side, a winding knob 15 that is rotated for each frame is exposed, and an eyepiece window 6b (see FIG. 1) is provided at a position facing the objective window 6a.

The photographing lens 10 is moved forward along the optical axis 10a from the normal photographing position where the photographing distance is focused in a range from about 1 m to infinity, and the photographing distance is adjusted. Is slidable together with the lens barrel 5 between a close-up photographing position where focus is achieved at around 50 cm. The mode switching lever 9 is slidable to a normal position, a close position, and a self position corresponding to the normal photographing mode, the close photographing mode, and the self photographing mode. On the exterior paper 4, “normal”, “normal”,
Information on "proximity" and "self" is written.

In this film unit with a lens, the finder 6 is disposed almost directly above the photographing lens 10, and the optical axis 10a of the photographing lens 10 and the optical axis 16 of the finder 6 are displaced in the left-right direction of the unit body 3. Is almost “0”, but is largely apart in the vertical direction. Therefore, when the shooting distance is short, the parallax in the vertical direction increases. Therefore, when photographing is performed in the close-up photographing mode and the self-photographing mode as described in detail later, parallax is corrected by the correction mask 18 for parallax correction.

FIG. 1 schematically shows the structure of a main part of a film unit with a lens. The unit body 3 is loaded with a film cartridge 20 at the time of manufacture. The film cartridge 20 is currently commercially available
The IX240 type of Advanced Photo System is used. The cartridge shell 21 and the photo film 2 are used.
And 2. As in the case of the conventional lens-fitted photo film unit, the photo film 22 is loaded into the film chamber of the unit body 3 in a state of being pulled out from the cartridge shell 21 and formed into a roll, and the cartridge shell 21 is loaded in the cartridge chamber. .

One end of the photographic film 22 is locked to a spool 23 rotatably built in the cartridge shell 21. The hoisting knob 15 is rotatably arranged at an upper part of the cartridge chamber, and has a drive shaft 1 provided at a lower part thereof.
5a is engaged with the end of the spool 23. By rotating the winding knob 15, the photographed portion of the photographic film 22 is wound into the cartridge shell 15, and
At the same time, an unexposed portion is set behind the taking lens 10.

A dark box (not shown) is provided between the photographic lens 10 and the photographic film 22 to light-tightly block the photographic optical path. On the front of the dark box, there is provided a shutter opening 25 for allowing photographic light to enter the dark box.
An aperture 26 for defining the size of the photographing frame on the second 2 is formed. The shooting frame is, for example, IX240
Model standard print size (H size: 89 x 158m
15. Standard screen size with the same aspect ratio as in m)
It is defined by an aperture 26 to 7 × 30.2 mm. An aperture stop 2 is provided between the shutter aperture 25 and the taking lens 10.
7 and a swingable shutter blade 28 are arranged. The shutter blade 28 is formed by a spring (not shown).
Is biased in the closing direction.

When the release button 11 is pressed,
The shutter blade 28 is turned in a direction to open the shutter opening 25 against the bias of the spring, and is turned in a direction to close the shutter opening 25 by the spring after the shutter opening 25 is fully opened. This one-way reciprocating swing of the shutter blade 28 opens and closes the shutter opening 25 to perform photographing. During the opening and closing of the shutter opening 25, the photographing light transmitted through the photographing lens 10 and emitted from the aperture stop 27 enters the dark box from the shutter opening 25 and is exposed in the aperture 26 to the portion of the photographic film 22 exposed in the aperture 26. Exposure.

The photographing lens 10 has a mode switching lever 9
In conjunction with the operation of the lens barrel 5, the lens barrel 5 is moved by the lens moving mechanism 29.
Is moved in the direction of the optical axis 10a, and thereby is slid between the normal shooting position and the close-up shooting position.

The finder 6 is composed of an objective lens group 30 and an eyepiece 31. Objective lens group 30
Is a reverse Galilean type in which a single lens 32 having a convex surface on the object side is formed, and a virtual image of an object (subject) formed by the lens 32 is magnified by a convex eyepiece 31 for observation. . A half mirror (semi-transmissive mirror) 33 is formed on the surface of the lens 32 that is convex on the object side. Since the half mirror 33 is formed on a surface that is convex toward the object side of the lens 32, the half mirror 33 has a convex surface having substantially the same radius of curvature as the first surface 31a when viewed from the object side.

The viewfinder 6 functions as a see-through viewfinder in the normal photographing mode and the close-up photographing mode by looking through the eyepiece side window 6b, and self-viewing by observing the reflected image of the photographer on the half mirror 33. Functions as a self-portrait viewfinder in shooting mode. In the following description, for convenience of explanation, the visual field range observed through the eyepiece side window 6b will be referred to as a finder visual field range, and the range of the reflected image observed on the half mirror 33 will be referred to as a reflective visual field range.

The half mirror 33 is formed by evaporating a metal such as aluminum on the first surface of the lens 32. In order to favorably balance the brightness of the subject image when the viewfinder 6 is used as a see-through viewfinder and the brightness of a reflected image when the viewfinder 6 is used as a self-portrait viewfinder, the half mirror 33 has a range of 400 nm to 700 nm. The light transmittance of any one of the above wavelengths is set to 20% or more and 75% or less. If the transmittance of the half mirror 33 is set high, the brightness of the subject image when used as a see-through finder can be observed brightly, and if it is set low, the reflected image when used as a self-portrait finder becomes bright. Can be observed. The transmittance of the half mirror 33 is desirably 35% or more and 65% or less.

Further, similarly to the half mirror used in the conventional Arbata type finder, it is more preferable that the half mirror 33 is a multilayer film formed by forming various kinds of metals in multiple layers, for example, to have the spectral characteristics shown in FIG. In the case of the spectral characteristics shown in FIG. 3, since the transmittance on the short wavelength side is high, the transmission image has a strong tendency to be blue, but the recognition rate can be increased. Conversely, the reflected image tends to change from yellow to red, but the recognition rate can be increased by observing the color in those wavelength ranges.

The spectral characteristics are not limited to those shown in FIG. 3. For example, by increasing the transmittance on the long wavelength side,
The reflectance on the short wavelength side may be increased. Also,
In this case, since the half mirror 33 appears to be clearly colored, a wavelength range in which the reflectance is increased may be selected according to the design and coloration of the film unit with the lens.

When the half mirror 33 is formed by aluminum evaporation, there is an advantage that the manufacturing cost can be reduced. On the other hand, when the half mirror 33 is a multilayer film, the transmitted image becomes brighter even if the reflected image has the same brightness because the absorption of light inside the half mirror is smaller than that of the aluminum mirror. There are advantages.

In this embodiment, the objective lens group 30 is
Although the objective lens group 30 is constituted by a plurality of lenses, the objective lens group 30 may be constituted by a plurality of lenses so as to have a lens having a convex surface at least on the object side. When there are a plurality of convex surfaces on the object side, a half mirror can be formed on an arbitrary surface as long as the lens surface can obtain a predetermined field ratio when a reflected image on the half mirror is observed. it can.
At this time, if a half mirror is formed on a lens surface other than the front surface, it is possible to prevent adhesion of dirt and scratches on the half mirror. Further, a non-power meniscus lens may be added to the objective lens group 30, and a half mirror may be formed on the meniscus lens.

An object side window 6a is provided on the front surface of the lens 32. The objective side window 6a has a rectangular opening having the same aspect ratio as the aperture 26. The range of the subject observed through the finder 6, that is, the finder visual field range is defined by the objective side window 6 a in a rectangular shape.

The correction mask 18 can be inserted into and removed from the front surface of the half mirror 33 on the object side of the half mirror 33, and the correction mask 18 covers the upper portion of the half mirror 33 and retracts from the front surface of the half mirror 33. The mask is moved to the retracted position by the mask moving mechanism 35. Further, the light-shielding plate 36 is slid by the light-shielding plate moving mechanism 37 between a light-shielding position between the eyepiece lens 31 and the lens 32 and a retracted position retracted from between the eyepieces 31 and 32.

In this film unit with a lens, the correction mask 18 is inserted and removed in front of the object side window 6a. The correction mask 18 is used in the close-up photographing mode and the self-photographing mode. And the parallax correction is performed so that the center of the actual photographing screen and the center of each field of view range coincide with each other. It may be a position. In the case of this example, the correction mask 18 may be inserted and removed between the lens 32 and the object side window 6a.

The interlocking mechanism 38 drives the lens barrel 5, the correction mask 18, and the light shielding plate 36 via the lens moving mechanism 29, the mask moving mechanism 35, and the light shielding plate moving mechanism 37 in conjunction with the operation of the mode switching lever 9. I do. Mode switching lever 9
Is moved to the normal position, the interlocking mechanism 38
Moves the lens barrel 5 through the lens moving mechanism 29 to move the photographing lens 10 to the normal photographing position, and moves the correction mask 18 and the light shielding plate 36 through the mask moving mechanism 35 and the light shielding plate moving mechanism 37. Each moves to the evacuation position.
When the mode switching lever 9 is slid to the close position, the photographing lens 10 is moved to the close photographing position, the correction mask 18 is moved to the correction position, and the light shielding plate 36 is moved to the retracted position. Further, when the mode switching lever 9 is slid to the self position, the photographing lens 10 is moved to the close-up photographing position, the correction mask 18 is moved to the correction position, and the light shielding plate 36 is moved to the light shielding position.

As shown schematically in FIG. 4, when the photographing distance L to the subject indicated by reference numeral 40 is as short as about 50 cm, the optical axis 10a of the photographing lens 10 and the optical axis 16 of the finder 6 are moved up and down. , The effect of parallax due to this cannot be ignored. That is, in a state where the finder visual field range is defined only by the objective side window 6a, the center of the finder visual field range coincides with the optical axis 16, and the optical axis 16 at the position of the subject 40 and the optical axis 10a of the photographing lens 10 Is large in the vertical direction, so that the center of the shooting screen does not coincide with the center of the finder visual field range.

Therefore, when performing close-up photography, the correction mask 18 is inserted into the front surface of the lens 32 and the objective window 6 is inserted.
The upper part of the original finder visual field defined by a is masked, and the center of the corrected finder visual field indicated by reference numeral 41 is made to coincide with the center of the photographing screen. This allows the photographer to know the center of the shooting screen when performing close-up shooting.

Further, when performing self-portrait photographing in which the photographer himself is photographed at the same photographing distance as in close-up photographing, he observes the reflected image on the half mirror 33 with his eyes on the optical axis 16. The difference between the center of the reflection field range defined by the objective side window 6a and the optical axis 10a of the photographing lens 10, that is, the parallax at the time of self-photographing portrait, as can be seen from FIG. Is equivalent to Therefore, by moving the correction mask 18 to the correction position in the self-photographing mode and masking the upper part of the reflective visual field range as in the close-up photographing mode, the center of the masked reflective visual field range is indicated by reference numeral 41. And coincides with the center of the shooting screen. This allows the photographer to know the center of the photographing screen even when performing self-photographing.

As described above, by inserting and removing the correction mask 18 on the object side with respect to the half mirror 33, the correction mask 18 can be commonly used for close-up photography and self-portrait photography.

The light-shielding plate 36 cuts external light incident from the eyepiece side window 6b in front of the half mirror 33 during self-portrait photographing, and this external light transmits through the half mirror 33 to the object side, that is, photographing. So that it is not injected to the user. This makes it easy to see the reflected image on the half mirror 33. The insertion position of the light shielding plate 36 may be any position as long as it is on the rear side of the half mirror 33, that is, between the eyepiece side window 6b and the half mirror 33, and the eyepiece side window 6b may be closed from the outside.

When the half mirror 33 is used as a viewfinder for self-portrait, the viewing ratio is 85% with respect to the vertical direction of the photographing screen when the reflected image is observed with a single eye from a distance of 50 cm from the front of the viewfinder 6. Hereinafter, it is set to be 85% or less with respect to the horizontal direction of the photographing screen. Further, when the distance between the eyes is set to 60 mm and observed with both eyes, the distance is set to 100% or less in the direction of the distance between the eyes.
The field of view is determined based on a range where the image is actually captured in the frame defined by the aperture 26 as a shooting screen, and based on this shooting screen. Note that the field ratios in the horizontal and vertical directions of the photographing screen are values when the correction mask 18 is at the correction position. Also, Advanced Photo Sy
In the stem, while exposing the shooting frame at the standard screen size,
C size (89 × 127) with different aspect ratio when shooting
mm) can be designated. For this reason, the field of view may be determined as that for a photographing screen that is actually a printed photograph.

When used as a finder for self-portrait, the field of view changes according to the radius of curvature of the half mirror 33, and the radius of curvature of the half mirror 33 is substantially equal to the radius of curvature of the lens surface on which it is formed. ,
By adjusting the radius of curvature of the lens surface of the lens 32 on the object side, it is possible to adjust the field rate as a self-portrait finder.

In this adjustment, the power of the objective lens group 30 and the eyepiece 31 becomes weaker as the finder magnification as the see-through finder becomes higher.
In the case of this example, the degree of freedom in selecting the radius of curvature of the lens surface of the lens 32 on the object side increases. Therefore, the higher the finder magnification, the easier it is to adjust the field of view as a self-portrait finder. Also, the objective lens group 3
When defining the finder field of view near 1, the higher the finder magnification, the higher the objective lens group 30 (lens 32)
Since the diameter of the half mirror becomes large and the size of the half mirror can be enlarged accordingly, a large reflected image can be observed, and framing can be easily performed. For such a reason, the finder magnification of the finder 6 is made as high as possible, and is set to be 0.45 times or more.

Next, the operation of the above configuration will be described. When photographing a subject in a range from approximately 1 m to infinity, the mode switching lever 9 is set to the normal position. Then, the operation of the mode switching lever 9 is performed by the interlocking mechanism 38.
To the respective moving mechanisms 29, 35, 37. The lens moving mechanism 29 moves the lens barrel 5 to set the photographing lens 10 to the normal photographing position. Further, the mask moving mechanism 35 moves the correction mask 18 and the light shielding plate moving mechanism 37 moves the light shielding plate 36 to the retracted position. Further, the photographer operates the strobe operating member 8 as necessary to select whether or not to emit strobe light.

Thereafter, the photographer performs framing by looking through the viewfinder 6 from the eyepiece side window 6b from the back side of the film unit with the lens. At this time, the finder 6
The finder field range is defined by the objective side window 6a. Therefore, as shown in an example in FIG. 5, for example, a range slightly narrower than the actual shooting screen 51 can be observed in the finder visual field range 50. Also, since the shooting distance is relatively long, the center of the shooting screen 51 and the center of the finder visual field range 50 substantially coincide.

After the framing, the release button 11 is pressed to take a picture. Release button 11
Is pressed, the shutter opening 25 is opened and closed by the shutter blades 28 in the same manner as in the conventional lens-fitted film unit, and the photographic film 22 is exposed,
A subject image slightly wider than the finder visual field range 50 is captured.

When photographing flowers and the like in close proximity, the mode switching lever 9 is set to the close position. By operating the mode switching lever 9, the lens barrel 5 is moved, the photographing lens 10 is set to the close-up photographing position, and the correction mask 18 is moved to the correction position by the mask moving mechanism 35. Further, the light shielding plate 36 is set at the retracted position. The photographer adjusts the distance between the subject and the film unit with the lens so that the photographing distance becomes 50 cm, performs framing by looking through the viewfinder 6 from the eyepiece side window 6b, and then presses the release button 11. .

At this time, the finder visual field range is defined by the objective side window 6a and the correction mask 18. As shown in an example in FIG. 6, the viewfinder field range 50 defined by the objective side window 6a due to the influence of parallax.
Is shifted upward with respect to the actual shooting screen 52, and the center thereof also shifts upward with respect to the center of the shooting screen 52. However, since the upper portion of the finder field range 50 is masked by the correction mask 18, the center of the finder field field 53 actually observed through the finder 6 is displaced downward, and the center of the finder field field 53 is shifted to the photographing screen. 52 coincides with the center. Therefore, the photographer can observe the subject image in the finder field of view 53 after the regulation, and can photograph the subject while making the center of the photographing screen coincide with the center of the desired subject.

Further, when the photographer performs self-portrait photographing with himself / herself as a subject, the mode switching lever 9 is set to the self position. Mode switching lever 9
When the camera is set to the self-position, the taking lens 10 is set to the close-up shooting position and the correction mask 18 is set to the correction position in the same manner as in the close-up shooting mode. Board 36
Is moved to the light blocking position.

The photographer holds the photographing lens 10 toward the photographer and performs framing while observing the reflected image on the half mirror 33. At this time, since the external light incident from the eyepiece side window 6b is cut by the light shielding plate 36, the external light does not pass through the half mirror 33 and is not observed by the photographer, so that the photographer is reflected. An image can be observed well.

FIG. 7 shows an example of the relationship between the reflected image on the half mirror 33 and the photographing screen. As shown in FIG. 7, the upper part of the half mirror 33 is hidden by the correction mask 18 on the object side. The framing is performed by observing the reflection image in the reflection field range 54 masked by the correction mask 18. Therefore, framing can be performed in a state where the center of the shooting screen 55 and the center of the reflection field range 54 coincide with each other, as in the close-up shooting mode.

Thereafter, when the release button 11 is pressed,
An image of the photographer is exposed on the photographic film 22. Of course, since the radius of curvature of the half mirror 33 is adjusted so that the field ratio at this time is in the above range, the image observed on the half mirror 33 is not exposed to the photographic film 22. There is no such thing.

In the close-up shooting mode and the self-photographing mode, if the strobe light is emitted weaker than that in the normal shooting mode, good strobe shooting can be performed even in the close-up shooting and the self-portrait shooting. Also, in the above-described film unit with a lens, the viewfinder is disposed almost directly above the taking lens, so that the correction mask is inserted so as to narrow the field of view only in the vertical direction. When the amount of deviation of the viewfinder optical axis in the left-right direction with respect to the optical axis is not negligible, a parallax correction may be performed by inserting a correction mask so as to narrow the left-right direction of the field of view. .

[0062]

Next, first and second embodiments will be described. In the first and second embodiments, members common to the above description are given the same reference numerals and described.

[First Embodiment] FIG. 8 shows a first embodiment of the configuration of the finder. In the first embodiment,
The objective lens group 30 is composed of one lens 32, and the half mirror 33 is formed on the object-side surface (first surface) of the lens 32. The viewfinder magnification of the viewfinder 6 is "0.
74 times ", which satisfies the finder magnification condition of" 0.45 times "or more. Table 1 below shows the lens data of the first embodiment. In addition. The surface number is a number given to each lens surface of the lens 32 and the eyepiece 31 of the objective lens group 30 in order from the object side, and the interval represents a lens thickness or an air gap between the next surface. (Unit is mm).

[0064]

[Table 1]

The lens surface indicated by (*) in Table 1 is an aspherical surface formed so as to satisfy the following conditional expression. In the equation, c is the reciprocal of the radius of curvature, and h represents the height of the light beam from the optical axis. Table 2 shows each aspheric coefficient. ^{Condition: Z = ch 2 / [1} + √ {1- (1 + k) c 2 h
² ｝] + Ah ⁴ + Bh ⁶ + Ch ⁸ + Dh ¹⁰

[0066]

[Table 2]

The following Table 3 shows the size of the finder visual field range when viewed through the eyepiece side window 6b, the field ratio, the size of the reflective visual field range when observing the reflected image on the half mirror 33 from the front of the lens 32, The field of view is shown. The unit of each size in Table 3 is “mm”. Each size of the finder field range and the reflection field range is at a position 50 cm away from the front surface of the lens 32 of the finder 6. The size of the reflection field range and the field ratio are obtained when the reflection image on the half mirror 33 is observed from a distance of 50 cm from the front surface of the lens 32. Further, the optical axis 16 of the finder 6 with respect to the optical axis 10a of the taking lens 10
Is set to 20 mm in the vertical direction and 5.6 mm in the horizontal direction.
They are arranged with an interval of 3 mm. The field ratio in the interpupillary direction is described in the column of the lateral direction assuming that the interpupillary direction matches the lateral direction (longitudinal direction) of the photographing screen.

[0068]

[Table 3]

As can be seen from Table 3, in the first embodiment, the field of view when the finder 6 is used for self portrait by observing the reflected image on the half mirror 33 with a single eye from a distance of 50 cm. Is 69.90% in the vertical direction of the shooting screen and 78.30 in the horizontal direction.
%, And the field rate in the horizontal direction (interpupillary direction) when observed with both eyes is 90.35%, which satisfies the condition of the field rate described above.

The half mirror 33 is obtained by depositing aluminum on the surface of the lens 32 on the object side, and forming a protective coat on the surface of the aluminum deposited layer. FIG. 9 shows the transmittance of the half mirror 33 together with the reflectance. Note that the reflectivity is represented by a representative value because the measurement conditions varied. As can be seen from FIG. 9, the half mirror 33 of the first embodiment has a transmittance of 20% or more at each wavelength in a short wavelength range from about 430 nm, and has a transmittance of about 400 nm at the maximum of 3%.
It is about 2%. Therefore, from 400 nm to 700 n
The transmittance of any single wavelength light in the m wavelength range is 20%
The condition of not less than 75% is satisfied.

[Second Embodiment] FIG. 10 shows a second embodiment of the configuration of the finder. The objective lens group 30 in the second embodiment includes two lenses 32a and 32b.
In the second embodiment, the half mirror 33 is formed on the third surface, that is, the lens surface on the object side of the lens 32b. The finder magnification of the finder 6 is "0.55 times", which satisfies the finder magnification condition.

The lens data of the second embodiment is shown in Table 4 below.
Shown in In addition. The surface numbers correspond to the lenses 32a and 32b of the objective lens group 30 and the eyepiece 31 which are sequentially assigned from the object side.
Is the number given to each lens surface, and the space represents the lens thickness or air space with the next surface (the unit is m
m).

[0073]

[Table 4]

The lens surface indicated by (*) in Table 4 is an aspherical surface formed so as to satisfy the following conditional expression. In the equation, c is the reciprocal of the radius of curvature, and h represents the height of the light beam from the optical axis. Table 5 shows each aspheric coefficient. ^{Condition: Z = ch 2 / [1} + √ {1- (1 + k) c 2 h
² ｝] + Ah ⁴ + Bh ⁶ + Ch ⁸ + Dh ¹⁰

[0075]

[Table 5]

Table 6 below shows the size of the finder visual field range, the field rate, and the lens 32a when looking through the eyepiece side window 6b.
2 shows the size of the reflection field range and the field rate when the reflection image on the half mirror 33 is observed from the front surface of FIG. Table 6
The unit of each size is “mm”. As in the first embodiment, each size of the finder visual field range and the reflection visual field range is
The size of the reflected visual field range and the field ratio are obtained when the reflected image on the half mirror 33 is observed from a distance of 50 cm from the front surface of the lens 32, at a position 50 cm away from the front surface of the lens 32a of the finder 6. is there.
The amount of deviation of the optical axis 16 of the finder 6 from the optical axis 10a of the photographing lens 10 is 20 mm in the vertical direction and 5.6 mm in the horizontal direction.
3 and 0.3 mm apart. The field ratio in the interpupillary direction is described in the column of the lateral direction assuming that the interpupillary direction matches the lateral direction (longitudinal direction) of the photographing screen.

[0077]

[Table 6]

As can be seen from Table 6, the viewfinder 6
The field of view when using for self portrait is 75.53% in the vertical direction of the shooting screen and 80.33 in the horizontal direction, and the horizontal direction (interpupillary direction) when observed with both eyes Is 90.69%, which satisfies the above-described condition of the field ratio. The half mirror 33 is formed in the same manner as in the first embodiment, has the same transmittance, and satisfies the condition of the transmittance.

In the above description, the film unit with a lens has been described. However, the present invention is not limited to this, and can be applied to various cameras such as a compact camera. In addition, the present invention can be used for various types of finders other than the inverted Galilean viewfinder. further,
It is also possible to use the self-portrait half mirror as the reticle half mirror of the Aruba finder.

[0080]

As described above, according to the present invention,
The objective lens group of the finder is configured to have at least one convex surface on the object side, and a half mirror is formed on the convex surface so that the range of the reflected image observed on the half mirror has a predetermined field rate. Therefore, it goes without saying that self-portrait shooting can be performed without preparing an adapter or the like, needless to say that it can be used for normal shooting. Further, since the half mirror is formed on the lens surface of the objective lens group, it is not lost, a storage space can be made unnecessary, and there is no restriction on the shape of the camera body.

When the mode is switched to the self-portrait mode, parallax can be corrected by inserting a correction mask so as to cover a part of the half mirror on the object side with respect to the half mirror. This correction mask can also be used as a correction mask in close-up photography. Furthermore, by inserting a light shielding plate on the back side of the half mirror and cutting external light incident from the eyepiece side, the reflected image on the half mirror can be easily seen.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a configuration of a film unit with a lens embodying the present invention.

FIG. 2 is a perspective view showing an appearance of a film unit with a lens.

FIG. 3 is a graph showing an example of the transmittance of a half mirror.

FIG. 4 is an explanatory diagram illustrating parallax correction during close-up shooting.

FIG. 5 is an explanatory diagram showing a relationship between a finder visual field range and a shooting screen in a normal shooting mode.

FIG. 6 is an explanatory diagram showing a relationship between a finder visual field range and a shooting screen in a close-up shooting mode.

FIG. 7 is an explanatory diagram showing a relationship between a reflected image on a half mirror and a photographing screen in a self-photographing mode.

FIG. 8 is an optical path diagram showing a first embodiment of a finder according to the present invention.

FIG. 9 is a graph showing the transmittance of the half mirror of the first embodiment.

FIG. 10 is an optical path diagram showing a second embodiment of the finder according to the present invention.

[Explanation of symbols]

 Reference Signs List 6 Finder 6a Object side window 9 Mode switching lever 10 Photographing lens 18 Correction mask 22 Photo film 30 Objective lens group 31 Eyepiece 33 Half mirror 36 Light shielding plate

Continuation of front page (72) Inventor Takayuki Kuriyama 210 Nakanakanuma, Minamiashigara-shi, Kanagawa Prefecture Fuji Photo Film Co., Ltd. F-term (reference) 2H018 AA02 BA06 2H101 AA01 BB14

Claims (7)

[Claims] 1. An objective lens group having at least one convex surface on the object side, an eyepiece, and a half mirror formed on the convex surface and having a convex surface on the object side,
When the reflected image on the half mirror is observed with a single eye at a distance of 50 cm from the forefront of the objective lens group to the object side as a viewfinder for self-portrait, the field of view in the vertical and horizontal directions of the photographing screen is 85 %. 2. As a self-portrait viewfinder, a reflected image on the half mirror is observed with both eyes at a distance of 50 cm from the forefront of the objective lens group to the object side, and a photographing screen is taken when the interpupillary distance is 60 mm. 2. The visual field ratio in the interpupillary direction is 100% or less.
Viewfinder as described. 3. The device according to claim 1, wherein the half mirror has a thickness of 400 nm to 7 nm.
2. The light transmittance of a single wavelength light in a wavelength range of 00 nm is not less than 20% and not more than 75%.
Or the finder according to 2. 4. The device according to claim 1, wherein the half mirror has a thickness of 400 nm to 7 nm.
2. The transmittance of light having a single wavelength in a wavelength range of 00 nm is 35% or more and 65% or less.
Or the finder according to 2. 5. The finder according to claim 1, wherein the finder magnification is 0.45 times or more. 6. A camera capable of switching to a self-portrait mode in which a photographer performs close-up photographing with the photographer himself as a subject, comprising the finder according to claim 1; When switched to the portrait mode, the half mirror is inserted at a position covering a part of the half mirror on the object side with respect to the half mirror, and the center of the photographing screen and the center of the range of the reflected image observed on the half mirror are aligned. A camera comprising a correction mask for correcting parallax so as to match. 7. A camera capable of switching to a self-portrait mode in which a photographer performs close-up photographing with the photographer as a subject, comprising: the finder according to claim 1; A camera, comprising: a light-shielding plate that is inserted behind the half mirror and that shields the half mirror from external light incident from the eyepiece when the mode is switched to the portrait mode.