JPH039338A - Film unit with variable power lens - Google Patents

Abstract

PURPOSE:To reduce the number of composing lenses and to obtain the miniaturized, lightweight film unit by freely attaching and detaching lenses, which compose a photographic optical system and a finder, according to variable power. CONSTITUTION:For wide-photographing, a plano-convex lens 4 is housed in a first housing 1 as the photographic optical system with a convex surface facing forward. A plano-concave lens 5 is housed in the front of a second hous ing 2 as the finder optical system with a concave surface facing backward, and a plano-convex lens 6 is housed in the rear of the housing 2 with a covex surface facing backward. When telephotographing is carried out by varying a magnification of the film unit having the lenses, each of the convex lenses 4 and 6 is removed from the first and second housings 1 and 2, respectively, and each of the finder optical system and photographic optical system is com posed by housing the lens 4 in the second housing 2 with the convex surface facing backward and by housing the lens 6 in the first housing 1 with the con vex surface facing forward, respectively. Thus the number of lenses is reduced, and the miniaturized, lightweight film unit can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a film packaging container (hereinafter referred to as a lens-equipped film unit) that incorporates a photographic function such as a photographic lens and a shutter.

[Conventional technology]

Conventionally, when taking photographs, it is customary to load film into a camera. However, only a few people carry a camera with them at all times, and the majority of people feel inconvenienced because they don't have a camera with them when they want to take a photo.

On the other hand, lenses that have built-in lighting functions such as a photographic lens, shutter, and lighting device are installed in a light-tight container preloaded with a 110-size film cartridge (film sensitivity: 15O100) or 35m-size film, etc. Film units with attached cameras have become commercially available, making it easy to take photos anywhere, day or night.

On the other hand, in the compact camera market, high-performance cameras with variable magnification functions, with zoom or switchable photographic lenses, are becoming mainstream, replacing single-focus cameras.

[Problem to be solved by the invention]

As described above, although compact cameras have become more and more sophisticated, their prices have also increased, and they have also become larger and heavier, making them inconvenient to carry around all the time.

Furthermore, commercially available lens-equipped film units are only of single focus type, which do not meet recent needs.

Therefore, a configuration in which the lens-equipped film unit has a variable magnification function may be considered, but the photographing optical system and finder optical system used in compact cameras with a variable magnification function have a large number of lenses and a variable magnification function. Since the lens moving mechanism and the like are complicated, it would be inappropriate to use it as a lens-equipped film unit because it would lose its characteristics of being inexpensive, small, and convenient to carry.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a variable-magnification photographing lens and a variable-magnification film-equipped lens unit that is inexpensive, compact, and convenient to carry.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention provides a lens-equipped film unit that includes a finder section and a photographing section having at least one lens, in which the number of sheets in total of the finder section and the photographing section can be increased. Lenses are disposed, and at least a portion of the plurality of lenses moves between two positions, one on the optical axis of the photographing section and the other on the optical axis of the finder section, thereby controlling the viewfinder section and the photographing section. It changes the magnification of

[For production]

The present invention makes part or all of the lenses constituting the photographic optical system and the finder detachable in accordance with variable magnification, and also allows the lenses to be connected from the photographic optical system to the finder optical system or from the finder optical system to the photographic optical system. Since the lens can be moved to a variable magnification effect, some lenses can be shared between the photographing optical system and the finder optical system. Therefore, it is possible to provide a film unit with variable magnification type lens that is inexpensive, small, lightweight, and convenient to carry without reducing the number of lenses used in the entire camera.

〔Example〕

FIG. 1 is a perspective view of the lens-equipped film unit of this embodiment with the taking lens and finder lens removed, and FIGS. 2 and 3 are cross-sectional views taken along plane A-λ including the lens shown in FIG. As shown in the figure, the film unit includes a first storage section 1 that stores a photographic optical system and a second storage section 2 that stores a finder optical system, and a film unit main body that stores photographic film inside. A photographing optical system and a finder optical system are housed in each of the storage sections of No. 3.

Figures 2 and 3 show a wide-angle state and a telephoto state, respectively. In the wide-angle state, a plano-convex lens 4 fixed to the frame as a photographing lens with a focal length of 30 m is stored in the first housing 1 with its convex surface facing forward. do. Also, in the second storage part 2, there is a focal length j! on the front side as a finder optical system. A framed plano-concave lens 5 of 1-20 mm is housed with the concave surface facing backward, and the focal length is 11i on the rear side of the concave lens 5. A 50 m framed plano-convex lens 6 is housed with the convex surface facing backward. Although not shown in the figure, each lens frame is fixed to the film unit body 3 by a suitable fixing member. When changing the magnification of this lens-equipped film unit and performing telephoto shooting, as shown in FIG. Store the lens 6 in the second storage part 2 with its convex surface facing forward as a finder optical system.
It is stored in the storage section and used as a photographing optical system.

Now, the focal length of I/lens 4 and 5.6 is f4° fs, respectively.
fb and the diagonal length of the screen is 2d, the viewfinder magnification is T at wide angle. is the half angle of view θ shown by equation (1) and photographed. The tangent of can be shown by equation (2).

γ,,lζ-rs/r* ・−・−・・−・−・・−
・・・・−１−−−−・−・・・・・（1）tan
θ,! :id/t, -----------
------- (2) Similarly, the finder magnification Tv at telephoto mode can be expressed by equation (3), and the tangent of the half angle of view θ to be photographed can be expressed by equation (4).

T, ζ-f, /f, (3) tan
θt 'id / f h
(4) Therefore, the viewfinder double angle at wide angle in this embodiment is T1ζ0.4, and the half angle of view for photographing is θ1! :i35
．． From 8", tan lI @ 'i is 0.721.Furthermore, the viewfinder magnification at telephoto is T7ζ0.666, and the half angle of view θ is 23.4° to tanθ
T-0, 433.

Although the photographic optical system and the finder optical system are variable in magnification in both wide-angle and telephoto positions, only three lenses are actually used in this lens-equipped film unit.

This is because in this embodiment, the lens 4 and the lens 6 are shared by the housing sections 1 and 2, so the number of lenses constituting the entire lens-equipped film unit can be reduced, and the variable magnification mechanism simply attaches and detaches the lens together with the frame. This makes it possible to create a lens-equipped film unit that is very inexpensive, small, lightweight, and convenient to carry.

However, the diopter of the finder magnification is often not O (,
There are many differences from the above formulas (1) and (3). now,
If the finder diopter at wide-angle is 4, the principal point distance between lenses 4 and 5 is H8, the finder diopter at telephoto is HT, then the principal point distance is Hw and Ha can be expressed by the following equations (5) and (6).

Hw-f s+ f a + f 4g・D @/10
00 -・-・(5) Ht-f s+ r b+f J
, "-Dt/1000 --- (6) Therefore, the diopter can be appropriately adjusted by selecting the principal point spacing and the focal length of the angle lens. The degree is Dh<O, D<0
Although it is better to use Dw −Dy −0, there is no particular problem.

In addition, the tangent of the half angle of view to be photographed is actually influenced by distortion aberration, and since focusing is performed at an overfocused position, the above formula (2)
The value determined from (4) and (4) may be different. In that case, it is best to adjust the F-number by adjusting the aperture diameter of an aperture shutter (not shown). In other words, let δ be the diameter of the minimum circle of confusion allowed on the film, and set the F-number of the photographing lens to F. Then, the hyperfocal distance α measured from the front focal point is expressed by the following equation (7).

α−fFu/(δ・F) (7) Therefore, the hyperfocal position is set to α1 for wide angle and telephoto. If α, then the following equations (8) and (9) are shown.

αei−rn”/(δ−F,) (8) α
t = f b”/ (δ・FT) (9
) As described above, by selecting the F number both at wide-angle and telephoto, the hyperfocal position can be adjusted freely. Further α. It is preferable to set αi for telephoto shooting.

Next, a second embodiment of the present invention will be described using FIGS. 4 and 5. FIG. 4 is a sectional view similar to FIG. 2 in the second embodiment during wide-angle photography.

A plano-convex lens 7 having a focal length of M35IIIIO and having a convex surface facing forward is fixed as a photographing lens in the first storage part 1 of the film unit main body. Also, the film body 8
In the second storage part 2, a lens 9, which is fixed to a frame in order from the front side, is a plano-concave lens A with a concave surface facing backward, a cemented lens B made by cementing a biconvex lens and a meniscus lens with a convex surface facing backward. It has a stored configuration. When changing the magnification of the lens-equipped film unit and performing telephoto shooting, as shown in FIG.
Therefore, in this example, there is no lens in the viewfinder during telephoto shooting, and the lens 9
is used as a converter lens in photographic optical systems.

Now, if the focal length of lens 7 is fl, and the magnification of lens 9 in the state shown in Figure 5 is T, then the finder magnification at wide angle is T.
w can be expressed by equations (1) to (1)'.

rw-1/γ, -···−m−−·−(1) 'Also, the half angle of view θ to be photographed. The tangent of is expressed as equation (2)' from equation (2).

tan θ knee d/f, −・−・−・−11−−−
------
As shown in FIG.

T1 = γ, −・−・−−−・−・・−・・
-(3)'tan θT! #d/ (yq −f
t) -------(4)' Also, formula (2)' and (
4) As in the first embodiment, the actual value may differ from the cost due to distortion. At that time, the same IF of the first embodiment
You can adjust the near focus position by adjusting the number. Now, the near focus position at wide-angle is α. , if the near focus position at telephoto is α7, α8 is calculated from equation (8) to equation (8)'
From equation (9), α1 becomes as shown in (9)'.

α, -1-. R/(δ・F,) (8)'
α tour re・ft)”/(δ・Fy)−・(9)
'Here, in the second embodiment, the lens 9 is like a comparator lens, so the F number is F depending on the lens 7.' =F takes a constant value.

Therefore, in order to adjust the near focus position between wide-angle and telephoto, the rear focal position of the photographing lens must be separated from the front of the film by a certain distance, and this distance must be set at 2. 2. Then, the following 2〇〇) and 00 will be obtained.

Zw-f, t/α1 -fge・　(6・F,)/f.

1 δ・Fl −・・・・・・・−−−−−−−−1・−
・−・−・・−１１−−−−・−00) 7, T=fge/α.

=(γ,・f,)1・(δ・Fa)/(r q, f
t)! −δ・FT −・・・・・・・・・−・・−・−
(11) Rather than adjusting 21 and zT in this way, it is better to adjust the near focus position.

Also, since it is an F-knee FT, 2. -2T, so as long as the lens 7 is fixed, α, <α will always be true.

The finder magnification at wide angle in this second embodiment is rw-0,
625, and the half angle of view θy to be photographed is ξ31.7' to tan θw'io, 618. Also, the finder magnification at telephoto is γT-1, and the half angle of view θT
From ζ23°, tan θ is ζ00424.

As described above, this embodiment has more lenses than the first embodiment, so it is slightly larger and heavier than the first embodiment.
-In terms of FL, it is inexpensive, small and lightweight. Moreover, lens 7
is fixed, preventing dust from entering the camera (
good.

Next, a third embodiment of the present invention will be described using FIGS. 6 and 7. FIG. 6 shows the configuration of the third embodiment during wide-angle photography. As in the second embodiment, the focal length 4 is placed in advance in the storage section 1 of the film unit main body with the convex surface facing forward.
A plano-convex lens 10 (lens 10) is fixed. On the front side of the storage section 1 of this film unit body 11, there is a frame with a magnification of 0.8 times consisting of three lenses: a plano-concave lens with a concave surface facing backward, a biconcave lens, and a plano-convex lens with a convex surface facing forward. A converter lens 12 is detachably provided, and together with the lens 10 constitutes a photographing optical system. On the other hand, a frame lens 13 with a magnification of 1/1.3 times, consisting of two lenses, a plano-concave lens with a concave surface facing the rear and a plano-convex lens with a convex surface facing the front, is stored in the housing 2, and constitutes a finder optical system. are doing. When changing the magnification of the lens-equipped film unit shown in the third embodiment and performing telephoto shooting, the front and rear directions of the lens section 120 are reversed and stored in place of the lens section 13, as shown in FIG. In preparation for the lens section 2, the front and rear directions of the lens section 13 may be reversed and the lens section 13 may be placed in the first storage section 1 instead of the lens section 12.

The viewfinder magnification during wide-angle shooting in this example is r, l#
o, '11, and the half angle of view θ-Li for photographing is 34.1°, so tan 0w 'io, 676. Also, the finder magnification during telephoto mode is TT-1.25, and the half angle of view θy! ==22.6” to t, a n θ
t'io, 416.

As described above, although the present embodiment has a larger number of lenses than the first embodiment, it has the advantage of being inexpensive, small and lightweight for boat fishing. Furthermore, the image quality can be improved because the number of lenses is slightly larger than in other embodiments.

However, in each of the embodiments of the present invention, the lens parts shared by the finder optical system and the photographic optical system are arranged with their directions reversed, but in order to correct aberrations, it is better to share them in the same direction. A good lens can be used like that.

Further, in each of the embodiments of the present invention, there is no description of a means for moving the lens during zooming, but a simple moving mechanism may be provided so that the lens can be replaced with one touch, or it may be replaced manually. It doesn't matter if you take out the lens and put it back in. In this case, manual is preferable because it can be created in the lightest manner.

Furthermore, although not shown in the examples, when the finder is an Albag type, the bright frame target may be built into the lens that is moved or replaced, or it may be a glass plate fixed to the finder section in advance or It may be installed in a lens that cannot be moved or replaced.In this case, the glass plate fixed to the viewfinder or the bright frame target installed in the lens can be used to view the wide-angle and telephoto lenses on the same plane and adjust the magnification accordingly. It is also possible to distinguish between the two, or by adjusting the magnification settings of the finder to 8 degrees, it is possible to prevent the wide-angle frame from being eclipsed out of the field of view when telephoto is used.

〔Effect of the invention〕

By sharing some or all lenses of the viewfinder optical system and the photographic optical system, the number of lenses used in the entire lens-equipped film unit can be reduced, allowing variable magnification in both the imager and finder sections. Despite having the functions, it is possible to provide a film unit with a lens that is low in cost, small in size, and lightweight.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a film unit base that accommodates a variable power lens according to each embodiment of the present invention, and FIG.
The figure is a cross-sectional view showing the lens configuration during wide-angle photography according to the first embodiment of the present invention, FIG. 3 is a cross-sectional view showing the lens configuration during telephoto photography according to the first embodiment of the present invention, and FIGS. 5 is a sectional view showing the lens configuration for wide-angle and telephoto shooting according to the second embodiment of the present invention, and FIGS. 6 and 7 are sectional views showing the lens configuration for wide-angle and telephoto shooting according to the third embodiment of the present invention, respectively. FIG. 1 First storage section. 2 Second storage section. 3--...------- Film unit body. Figure 1 Figure 2 Figure 6 Figure Figure 4 District procedural amendment August 28, 1990 1. 4 indications 1999 Patent Application No. 144450 2 Name of invention Variable magnification lens + i-type film Unit 3, Person making the amendment 1, Date of amendment order (voluntary) Representative Toshibe Shimoyama - 2 - 〆 - Nora, No number of claims increased by amendment (1) Page 3, line 11 of the specification Delete "easily". (2) "What is the viewfinder magnification?" on page 7, lines 4 and 5 of the specification is corrected to "What is the finder magnification?" (8) Correct "0jiyanai" in the second line of page 8 of the specification to "not 0." (4) "Different" on page 8, line 3 of the specification is corrected to "j that does not exactly match." (5) "Principal point spacing HTJ" on page 8, line 7 of the specification is changed to "principal point spacing (6) Correct "corner lens" to "each lens" on page 8, line 11 of the specification. (7) "You should do it." on page 8, lines 12 and 13 of the specification should be corrected to "you should do it.""at a certain position" is corrected to "at a position affected and hyperfocal." (9) From page 8, line 19 to page 9, line 2 of the specification, "The value may differ from the obtained value. In that case, ~adjustment should be made." should be corrected to the following sentence. "They do not exactly match. Also, the hyperfocal position can be set appropriately by adjusting the aperture diameter of the aperture shutter (not shown) and adjusting the F number. Correct it to J. ( 10) Correct "hyperfocal distance" on page 9, line 5 of the specification to "hyperfocal position." (11) On page 11, lines 10 and 11 of the specification, "The actual value may differ from the actual value due to aberrations." was changed to "The actual value may not exactly match the actual value due to aberrations, etc." There is.'' (12) Delete "In that case, you can make ~ adjustments." from lines 11 to 13 on page 11 of the specification. (18) Delete "It is best to adjust it in this way" from lines 12 to 13 on page 12 of the specification. (14) “Also, Fw=FT” on page 12, line 14 of the specification
"So" should be corrected to "In this way, when Fw = FT." (15) On page 13, line 7 of the specification, "It is good because it prevents dust from entering." is corrected to "It has the advantage of preventing dust from entering." (16) Delete "a little" from page 14, line 19 of the specification. (17) "Arbada" on page 15, line 14 of the specification is corrected to "Arbada". (18) In the specification, page 15, line 18, "lens that is not used" is corrected to "lens of the viewfinder section that is not used." (19) In the 6th and 7th lines of page 16 of the specification, it is stated that ``The lenses 9, 12, and 13 shown in the above embodiments are all afocal enough to be used for both photography and finder purposes. It goes without saying that it is a very sophisticated optical system.''

Claims (1)

[Scope of Claims] A film unit with a lens including a finder section and a photographing section having at least one lens, wherein a plurality of lenses are disposed in the finder section and the photographing section. , characterized in that the magnifications of the finder section and the photographing section are changed by moving at least some of the plurality of lenses between two positions, one on the optical axis of the photographing section and the other on the optical axis of the finder section. Film unit with lens.