Photographing apparatus for recording data on films

A data recording optical system which is to be used in cameras each having a plurality of photographing modes; comprises a display member and a single imaging lens system or a plurality of imaging lens systems; and is configured so as to modify data recording locations and change magnifications by moving a portion of the imaging lens system or selectively using the plurality of imaging lens systems.

BACKGROUND OF THE INVENTION 
a) Field of the invention 
The present invention relates to a photographing apparatus which is to be 
used for recording data such as photographing dates on film in cameras 
having a plurality of photographing modes for different image sizes. 
b) Description of the Prior Art 
Certain photographic cameras are configured to permit the recording of data 
such as the photographing date, time and other data in the corner of the 
film. 
Recording data such as the photographing dates, these data have 
conventionally been photographed from the rear side of the film (from 
sides opposite the photographic lens systems). For recording the data by 
this method, it is necessary to accommodate the recording mechanism in 
camera camera body, which inevitably thickens the rear cover of the 
cameras and makes it impossible to configure the camera in a compact 
manner. 
For this reason, it has recently been proposed to adopt a method for 
photographing such data from the front side of the film (from the side of 
photographic lens systems) and products using this method have already 
been developed. This method permits data to be recording on the films by 
using a character data display member and an imaging lens system which are 
disposed by effectively utilizing a space reserved in front of the film 
and outside of a range of space occupied by a light bundle coming from a 
photographic lens system. This method permits the recording mechanism to 
be disposed on the front side of the film, and thereby makes it possible 
to cofigure the camera compact in a while preventing manner the rear cover 
of the camera from being thickened. 
On the other hand, photography is now increasingly enjoyed while changing 
image sizes, as exemplified by cameras which permit panoramic photography. 
Further, photographs can now be enlarged to sizes larger than those 
conventionally available for strengthening impressions. When image sizes 
are changed, however, conventional cameras are incapable of recording some 
of the data or enlarge the data to awkward sizes. 
A character data recording apparatus disclosed by Japanese Patent Kokai 
Publication No. Sho 62-103,625 uses, on a rear cover of a camera, two 
light emitting members which have different character sizes and are 
switchable from one to the other. This character data recording apparatus 
basically requires the use of the same number of light emitting members 
same as the number of image sizes compatible with a camera to accommodate 
this apparatus, and makes it necessary to change the size and location of 
the characters in conjunction with switching of the image size. 
Further, Japanese Patent Kokai Publication No. Sho 63-27,823 discloses a 
recording apparatus which is configured so as to photograph character data 
from a side of a camera body. This conventional example photographs 
characters which are formed by light emitting members and imaged by 
imaging lens systems, and permits the size of the character data to be 
changed by switching the imaging lens systems from one to another, but is 
incapable of changing data recording locations. 
Furthermore, Japanese Patent Kokai Publication No. Hei 6-35,061 proposes a 
character data recording means which comprises a fixed light emitting 
member and two fixed lens units, and is capable of changing data recording 
magnifications and locations by switching light shielding members. 
Out of the conventional examples mentioned above, the character data 
recording apparatus disclosed by Japaneses Patent Kokai Publication No. 
Sho 62-103,625 is configured so as to photograph the character data from 
the rear, which is not desirable for configuring camera in a compact 
manner. 
Further, the recording apparatus proposed by Japanese Patent Kokai 
Publication No. Sho 63-27,823 is configured so as to photograph the 
character data from the side of a camera body and is capable of changing 
data recording magnifications, but does not permit changing recording 
locations. 
Furthermore, Japanese Patent Kokai Publication No. Hei 6-35,061 provides no 
concrete description of the optical system, even though it proposes 
character data recording means which is capable of changing booth data 
recording magnifications and locations. 
SUMMARY OF THE INVENTION 
A primary object of the present invention is to provide a photographing 
apparatus using an optical system which is to be used in cameras having a 
plurality of photographing modes provided for different image areas to be 
photographed (herein after to be referred to as image sizes), and 
configured so as to be capable of photographing character data such as 
photographing dates from a side of a camera body while changing both the 
data recording location and character size in conjunction with switching 
the photographing modes. 
A data recording optical system to be used in the photographing apparatus 
according to the present invention includes an optical system for 
recording characters and other data on an image receiver such as film, in 
a camera having a plurality of photographing modes for different image 
sizes. This optical system includes a display member and an imaging lens 
system for forming images of date provided by the display member on an 
image forming surface of the image receiving. The imaging lens system 
includes a main lens unit and an auxiliary lens unit. The main lens unit 
is moved, and the auxiliary lens unit is set and removed into and out of 
an optical axis, in conjunction with the switching of the photographing 
modes, thereby changing data recording locations (locations on the image 
receiving surface of the image receiver) and magnifications. 
Accordingly, the photographing apparatus using the data recording optical 
system according to the present invention includes a photographic lens 
system, an image receiver for receiving images formed by an imaging lens 
system and an optical system which is disposed on a side where rays to be 
used for photographing are incident on the image receiver so that it 
projects data different from the above-mentioned images onto the image 
receiver. The optical system includes a data display member and an imaging 
lens system for projecting rays from the data display member to the image. 
The imaging lens system includes a main lens unit and an auxiliary lens 
unit. A plurality of optical paths are formed from the data display member 
to different locations on the image receiver means by moving at least the 
main lens unit. The auxiliary lens unit is disposed in at least one of the 
plurality of optical paths, and data provided by the data display member 
are projected through the plurality of optical paths to different 
locations on the image receiver at different magnifications. 
Furthermore, the objects of the present invention can also be accomplished 
by configuring the photographing apparatus according to the present 
invention so as to be capable of setting and removing an auxiliary lens 
unit into and out of an optical path formed between a data display and an 
image receiver in conjunction with a movement of a main lens unit. 
A first type optical system to be used in the photographing apparatus 
according to the present invention is an optical system which is to be 
used in cameras each having a plurality of photographing modes for 
different image sizes, which is configured so as to photograph characters 
and other data onto a film from a side of a camera body, and which 
includes of a display member and an imaging lens system. The imaging lens 
system includes a main lens unit and an auxiliary lens unit. At least the 
main lens unit moves in conjunction with the switching of the 
photographing modes, and the auxiliary lens unit is set into an optical 
path in conjunction with the movement of the main lens unit. This optical 
system is configured so that an optical path to a film surface is moved by 
moving the main lens unit. In this manner, images of character data 
provided by the display member are formed at different locations on the 
film surface, and the magnification is changed by setting and removing the 
auxiliary lens unit into and out of the optical path. 
Further, a second type optical system to be used in the photographing 
apparatus according to the present invention, is an optical system which 
is to be used in cameras each having a plurality of photographing modes 
for different sized images is configured so as to photograph characters 
and other data onto a film surface from the side of a camera body. This 
system includes a data display member and a plurality of imaging lens 
systems each having at least one aspherical surface. This optical system 
permits images to be formed of character data provided by the data display 
member at different locations on the film surface and changing 
magnifications by using the imaging lens systems selectively in 
conjunction with the switching of the photographing modes. 
The second type of optical system to be used in the photographing apparatus 
according to the present invention, is an optical system which is to be 
used in cameras each having a plurality of photographing modes for 
different image sizes, and includes an optical system for recording 
characters and other data on an image receiver such as a film. This system 
uses an optical system which has a display unit and imaging lens systems 
each having at least one aspherical surface and is capable of changing the 
recording location of character data (locations on an image receiving 
surface of the image receiver) and the magnification by exchanging the 
imaging lens systems with one another in conjunction with switching of the 
photographing modes. 
Accordingly, a photographing apparatus using the second type data recording 
optical system according to the present invention includes a photographic 
lens system, an image receiver for receiving images formed by the 
photographic lens system and an optical system which is disposed on a side 
where rays to be used for photographing are incident on the image receiver 
so that it projects data which are different from the images to the image 
receiver. The optical system includes a data display member and a 
plurality of imaging lens systems which form optical paths for projecting 
rays from the data display member to the image receiver. Each of the 
imaging lens systems has at least one aspherical surface. Rays from the 
data display member are selectively led to the optical paths, whereby the 
photographing apparatus is capable of projecting data provided by the 
display member to different locations on the image receiver at different 
magnifications by switching the plurality of optical paths from one to 
another. 
FIG. 3A and FIG. 3B show diagrams exemplifying recording locations on a 
film surface: FIG. 3A showing a case wherein sizes of a longer side and a 
shorter side are changed, whereas FIG. 3B shows another case wherein a 
size of only the shorter side is changed. In other words, the image size 
shown in FIG. 3B corresponds to a panoramic image size. In each of FIG. 3A 
and FIG. 3B, a solid line 1 indicates an image size in a first mode in 
which characters 3 are recorded at a corner of the film surface. Further, 
a dashed line 2 indicates an image size in a second mode in which 
characters 4 are recorded at the location shown in the drawings. The 
characters 4 in the second mode are recorded in a size contracted as 
compared with that of the characters 3 in the first mode. That is to say, 
the data recording optical system to be used in the photographing 
apparatus according to the present invention described above is capable of 
changing recording locations and magnifications on the film surface as 
shown in FIG. 3A and FIG. 3B in conjunction with the switching of the 
photographing modes. Accordingly, the characters recorded in both the 
photographing modes are set in conditions equivalent to each other when 
photographs taken in both the modes are printed in the same size. Needless 
to say, these character data are not always in the same size but may have 
many optical sizes as long as they are not unnatural, and the recording 
location is modifiable on the film surface.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The data recording optical system according to the present invention will 
now be described in more detail below with reference to the preferred 
embodiments illustrated in the accompanying drawings. 
FIG. 1 shows a diagram descriptive of a concept selected for the first 
embodiment of the data recording optical system according to the present 
invention, whereas FIG. 2A and FIG. 2B show development views of an 
optical system to be used in the first embodiment of the present 
invention. In these drawings, reference numeral 11 represents a display 
member which provides characters and other data, for example, as shown in 
FIG. 3. Further, a reference numeral 12 designates an aperture stop, 
reference numeral 13 denotes a main lens unit, reference numeral 14 
represents an auxiliary lens unit, reference numeral 15 designates a film 
surface, reference numeral 16 denotes an optical axis in a first mode of 
the first embodiment and reference numeral 17 represents an optical axis 
in a second mode of the first embodiment. 
In the first mode of the first embodiment, images of characters are formed 
on the film surface 15 by the display member 11, the aperture stop 12 and 
the main lens unit 13. The main lens unit 13 used in the first embodiment 
is a prism-shaped lens unit which has a reflecting surface 13a as shown in 
FIG. 1 and serves for photographing, from the front side of the film 
surface 15, character data provided by the display member 11 disposed on a 
top surface of a camera onto the film surface 15. Further, the main lens 
unit 13 has a side surface of emergence (r.sub.3) which is configured as 
an aspherical surface for correcting spherical aberration and coma. 
In the second mode of the first embodiment, images of the characters are 
formed on the film surface 15 by cooperation of the display member 11, the 
aperture stop 12, the main lens unit 13 and the auxiliary lens unit 14. 
For setting the first embodiment in the second mode thereof, the display 
member 11, the aperture stop 12 and the main lens unit are moved 
integrally, for example, to the locations indicated by dashed lines in 
FIG. 1 until the auxiliary lens unit is aligned with the optical axis in 
the second mode. The auxiliary lens unit may be fixed at the location 
shown in FIG. 1 or interposed as shown in this drawing in conjunction with 
the movements of the display member 11, the aperture stop 12 and the main 
lens unit 13. The auxiliary lens unit in the first embodiment is a 
positive meniscus lens unit which has aspherical surfaces on both sides 
thereof. 
Though the main lens unit 13 and the others mentioned above may be moved 
along optical loci, these members are moved so as to keep a constant 
distance between the main lens unit 13 and the film surface 15, or in 
parallel with the film surface 15. Further, the first embodiment of the 
present invention has an advantage that it permits simplifying a moving 
mechanism of the main lens unit 13 and the other members only in a 
direction along a shorter side of the film surface 15. 
The first embodiment of the present invention has numerical data listed 
below: 
______________________________________ 
Embodiment 1 
______________________________________ 
(first mode) 
magnification = -1.0, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = .infin. (stop) 
d.sub.1 = 0.2000 
r.sub.2 = 4.7820 
d.sub.2 = 9.4000 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -5.3580 (aspherical surface) 
aspherical surface coefficients 
(3rd surface) 
P = 0.0000, A.sub.4 = 0.24044 .times. 10.sup.-2, A.sub.6 = -0.19065 
.times. 10.sup.-2 
A.sub.8 = 0.81215 .times. 10.sup.-3 
(Second Mode) 
magnification = -0.6, IO = 30 mm 
effective F number 4.8 
r.sub.1 = .infin. (stop) 
d.sub.1 = 0.2000 
r.sub.2 = 4.7820 
d.sub.2 = 9.4000 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -5.3580 (aspherical surface) 
d.sub.3 = 2.3000 
r.sub.4 = -5.8080 (aspherical surface) 
d.sub.4 = 3.6000 
n.sub.2 = 1.48993 
.nu..sub.2 = 57.66 
r.sub.5 = -2.5630 (aspherical surface) 
aspherical surface coefficients 
(3rd surface) 
P = 0.0000, A.sub.4 = 0.24044 .times. 10.sup.-2, A.sub.6 = -0.19065 
.times. 10.sup.-2 
A.sub.8 = 0.81215 .times. 10.sup.-3 
(4th surface) 
P = 3.0000, A.sub.4 = -0.12105 .times. 10.sup.-1, A.sub.6 = -0.42911 
.times. 10.sup.-2 
A.sub.8 = 0.85125 .times. 10.sup.-3 
(5th surface) 
P = 1.0000, A.sub.4 = 0.28810 .times. 10.sup.-2, A.sub.6 = -0.34962 
.times. 10.sup.-3 
A.sub.8 = 0.25709 .times. 10.sup.-3 
______________________________________ 
wherein the reference symbols r.sub.1, r.sub.2, . . . represent radii of 
curvature on surfaces of respective optical components, the reference 
symbols d.sub.1, d.sub.2, d.sub.3 and d.sub.4 designate thicknesses of the 
respective optical components and airspaces reserved therebetween, the 
reference symbols n.sub.1 and n.sub.2 denote refractive indices of the 
respective lens units, and the reference symbols .nu..sub.1 and .nu..sub.2 
represent Abbe's number of the respective lens units. 
In the first mode of the first embodiment, a distance as measured from the 
display member 11 to the film surface 15 is 30 mm, an imaging 
magnification is set at -1.0.times. and the optical system has an 
effective F number of 8.0. In the second mode of the first embodiment, the 
display member 11 is kept at the distance of 30 mm as measured from the 
film surface 15, an imaging magnification is set at -0.6.times. and the 
optical system has an effective F number of 4.8. 
In the first embodiment, light intensity is enhanced in the second mode due 
to a fact that the aperture stop is used commonly between the first mode 
and the second mode. For lowering light intensity in the second mode, it 
is sufficient to modify an exposure time, interpose an ND filter or mix a 
dye with a material to be used for forming the auxiliary lens unit 14. 
The second embodiment of the present invention has a configuration which is 
the same as that of the first embodiment and uses an optical system shown 
in FIG. 4A and FIG. 4B in development conditions. 
The second embodiment has numerical data which are listed below: 
______________________________________ 
Embodiment 2 
______________________________________ 
(first mode) 
magnification = -1.0, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = .infin. (stop) 
d.sub.1 = 0.2000 
r.sub.2 = 4.9510 
d.sub.2 = 9.9000 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -4.8970 (aspherical surface) 
aspherical surface coefficients 
(3rd surface) 
P = -2.5000, A.sub.4 = -0.88659 .times. 10.sup.-3 
A.sub.6 = -0.10070 .times. 10.sup.-2, A.sub.8 = 0.43666 
.times. 10.sup.-3 
(second Mode) 
magnification = 0.8, IO = 30 mm 
effective F number = 6.4 
r.sub.1 = .infin. (stop) 
d.sub.1 = 0.2000 
r.sub.2 = 4.9510 
d.sub.2 = 9.9000 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -4.8970 (aspherical surface) 
d.sub.3 = 2.9000 
r.sub.4 = .infin. 
d.sub.4 = 3.1000 
n.sub.2 = 1.48993 
.nu..sub.2 = 57.66 
r.sub.5 = -9.9880 (aspherical surface) 
aspherical surface coefficients 
(3rd surface) 
P = -2.5000, A.sub.4 = -0.88659 .times. 10.sup.-3 
A.sub.6 = -0.10070 .times. 10.sup.-2, A.sub.8 = 0.43666 
.times. 10.sup.-3 
(5th surface) 
P = 1.0000, A.sub.4 = -0.35947 .times. 10.sup.-2 
A.sub.6 = 0.13282 .times. 10.sup.-2, A.sub.8 = 0.22849 .times. 10.sup.-3 
______________________________________ 
In the second embodiment, an auxiliary lens unit 14 is configured as a 
plano-convex lens unit and has an aspherical surface (r.sub.5) on a side 
of a film surface. In a first mode of the second embodiment, a display 
member 11 is kept at a distance of 30 mm as measured from the film 
surface, an imaging magnification is set at -1.0.times. and the optical 
system has an effective F number of 8.0. In a second mode of the second 
embodiment, the display member 11 is kept at the distance of 30 mm as 
measured from the film surface, an imaging magnification is set at 
-0.8.times. and the optical system has an effective F number of 6.4 by 
using an aperture stop which is common to both the modes. 
FIG. 5 shows a diagram descriptive of a concept adopted for a third 
embodiment of the present invention, whereas FIG. 6A and FIG. 6B show 
development views of an optical system used in the third embodiment. In 
these drawings, reference numeral 11 represents a display member, 
reference numeral 12 designates an aperture stop, reference numeral 13 
denotes a main lens unit, reference numeral 14 represents an auxiliary 
lens unit, reference numeral 15 designates a film surface, reference 
numeral 16 denotes an optical axis in a first mode of the third embodiment 
and reference numeral 17 represents an optical axis in a second mode of 
the third embodiment. In both modes, the optical axes are straight and 
characters provided by the display member 11 are photographed nearly from 
a front side of the film surface. 
In the first mode of the third embodiment, images of characters are formed 
on the film surface by the display member 11, the aperture stop 12 and the 
main lens unit 13. 
In the second mode of the third embodiment, images of characters are formed 
on the film surface 15 by the display member 11, the aperture stop 12, the 
main lens unit 13 and the auxiliary lens unit 14. 
The third embodiment is switched from the first mode to the second mode 
thereof by moving the display member 11, the aperture stop 12 and the main 
lens unit 13 until they are aligned with the optical axis in the second 
mode. When the display member 11 is prepared in a pair and disposed on the 
optical axis 16 in the first mode and on the optical axis 17 in the second 
mode respectively, the third embodiment can be switched from the first 
mode to the second mode by moving only the aperture stop 12 and the main 
lens unit 13. 
The third embodiment has the following numerical data: 
______________________________________ 
Embodiment 3 
______________________________________ 
(first mode) 
magnification = -1.0, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = .infin. (stop) 
d.sub.1 = 0.2000 
r.sub.2 = 4.8420 
d.sub.2 = 10.0000 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -4.9580 (aspherical surface) 
aspherical surface coefficients 
(3rd surface) 
P = -2.4000, A.sub.4 = -0.67484 .times. 10.sup.-3, A.sub.6 = -0.10790 
.times. 10.sup.-2, 
A.sub.8 = 0.50112 .times. 10.sup.-3 
(second mode) 
magnification = -0.7, IO = 30 mm 
effective F number = 5.6 
r.sub.1 = .infin. (stop) 
d.sub.1 = 0.2000 
r.sub.2 = 4.8420 
d.sub.2 = 10.0000 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -4.9580 (aspherical surface) 
d.sub.3 = 3.4000 
r.sub.4 = 23.8920 
d.sub.4 = 4.2000 
n.sub.2 = 1.48993 
.nu..sub.2 = 57.66 
r.sub.5 = -5.5630 
aspherical surface coefficients 
(3rd surface) 
P = -2.4000, A.sub.4 = -0.67484 .times. 10.sup.-3 
A.sub.6 = -0.10790 .times. 10.sup.-2, A.sub.8 = 0.50112 
______________________________________ 
.times. 10.sup.-3 
The first mode of the third embodiment is designed for specifications which 
are the same as those for the first or the second embodiment, i.e., a 
distance of 30 mm as measured from the display member to the film surface, 
an imaging magnification of -1.0.times. and an effective F number of 8.0. 
In the second mode, the display member is kept at the distance of 30 mm as 
measured from the display member to the film surface, an imaging 
magnification is set at -0.7.times. and the optical system has an 
effective F number of 5.6. Further, the auxiliary lens unit is configured 
as a biconvex lens unit having spherical surfaces on both sides thereof. 
FIG. 7 shows a diagram descriptive of a concept selected for a fourth 
embodiment of the present invention, whereas FIG. 8A and FIG. 8B show 
development views of an optical system used in the fourth embodiment. In 
these drawings, reference numeral 11 represents a display member, 
reference numeral 12 designates an aperture stop, reference numeral 13 
denotes a main lens unit, reference numeral 14 represents an auxiliary 
lens unit, reference numeral 15 designates a film surface, reference 
numeral 16 denotes an optical axis in a first mode of the fourth 
embodiment and reference numeral 17 represents an optical axis in a second 
mode of the fourth embodiment. 
In the first mode of the fourth embodiment, images of characters are formed 
on the film surface 15 by the display member 11, the aperture stop 12 and 
the main lens unit 13. The main lens unit 13 is configured as a 
prism-shaped lens unit which has a reflecting surface and serves for 
photographing character data provided by the display member 11 disposed on 
a top surface of a camera from before the film surface 15. 
In the second mode of the fourth embodiment, images of the characters are 
formed on the film surface 15 by the display member 11, the aperture stop 
12, the main lens unit 13 and the auxiliary lens unit 14. For switching 
the fourth embodiment from the first mode to the second mode thereof, the 
aperture stop 12 and the main lens unit 13 are moved integrally until they 
are aligned with the optical axis 17 in the second mode. 
The fourth embodiment has numerical data which are listed below: 
______________________________________ 
Embodiment 4 
______________________________________ 
(first mode) 
magnification = -1.0, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = .infin. (stop) 
d.sub.1 = 0.2000 
r.sub.2 = 6.2800 
d.sub.2 = 9.7000 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -4.2360 (aspherical surface) 
aspherical surface coefficients 
(3rd surface) 
P = -0.5000, A.sub.4 = -0.49550 .times. 10.sup.-3 
A.sub.6 = -0.16538 .times. 10.sup.-3, A.sub.8 = 0.10243 
.times. 10.sup.-3 
(second mode) 
magnification = -0.7, IO = 35 mm 
effective F number = 8.7 
r.sub.1 = .infin. (stop) 
d.sub.1 = 0.2000 
r.sub.2 = 6.2800 
d.sub.2 = 9.7000 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -4.2360 (aspherical surface) 
d.sub.3 = 2.8000 
r.sub.4 = -4.6150 
d.sub.4 = 3.2000 
n.sub.2 = 1.48993 
.nu..sub.2 = 57.66 
r.sub.5 = -5.1230 (aspherical surface) 
aspherical surface coefficients 
(3rd surface) 
P = -0.5000, A.sub.4 = -0.49550 .times. 10.sup.-3 
A.sub.6 = -0.16538 .times. 10.sup.-3, A.sub.8 = 0.10243 
.times. 10.sup.-3 
(5th surface) 
P = -0.5000, A.sub.4 = 0.35973 .times. 10.sup.-3 
A.sub.6 = 0.67800 .times. 10.sup.-3, A.sub.8 = -0.46321 
______________________________________ 
.times. 10.sup.-3 
The first mode of the fourth embodiment is designed for specifications 
which are the same as those of the first, second or the third embodiment, 
i.e., a distance of 30 mm as measured from the display member to the film 
surface, an imaging magnification of -1.0.times. and an effective F number 
of 8.0. In the second mode of the fourth embodiment, the distance as 
measured from the display section to the film surface is changed to 35 mm, 
an imaging magnification is set at -0.7.times. and the optical system has 
an effective F number of 8.7. Further, the auxiliary lens unit is 
configured as a positive meniscus lens unit having an aspherical surface 
on one side thereof. 
In the fourth embodiment in which the display member is kept fixed, the 
modes are switched from one to the other by moving the main lens unit 13, 
etc. for a distance of 5 mm in parallel with the film surface. 
FIG. 9 shows a diagram illustrating a concept selected for a fifth 
embodiment of the present invention, whereas FIG. 10A and FIG. 10B show 
development views of this embodiment. In these drawings, reference numeral 
11 represents a display member, reference numeral 12 designates an 
aperture stop, reference numeral 13 denotes a main lens unit, reference 
numeral 14 represents an auxiliary lens unit, reference numeral 15 
designates a film surface, reference numeral 16 denotes an optical axis in 
a first mode of the fifth embodiment and reference numeral 17 represents 
an optical axis in a second mode of the fifth embodiment. 
In the first mode of the fifth embodiment, images of characters are formed 
on the film surface 15 by the display member 11, the aperture stop 12 and 
the main lens unit 13. The main lens unit is configured as a prism-shaped 
lens unit which has a reflecting surface and serves for photographing, 
from before the film surface 15, character data provided by the display 
member 11 disposed on a top surface of the camera. 
In the second mode of the fifth embodiment, images of the characters are 
formed on the film surface 15 by the display member 11, the auxiliary lens 
unit 14, the aperture stop 12 and the main lens unit 13. To switch the 
fifth embodiment from the first mode to the second mode thereof, the 
aperture stop 12 and the main lens unit 13 are moved integrally until they 
are aligned with the optical axis 17 in the second mode and auxiliary lens 
unit is interposed on a side of the aperture stop which is nearer the 
display member 11. 
The fifth embodiment has numerical data listed below: 
______________________________________ 
Embodiment 5 
______________________________________ 
(first mode) 
magnification = -1.0, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = .infin. (stop) 
d.sub.1 = 0.2000 
r.sub.2 = 5.0490 
d.sub.2 = 10.8000 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -4.4240 (aspherical surface) 
aspherical surface coefficients 
(3rd surface) 
P = -2.8000, A.sub.4 = -0.27070 .times. 10.sup.-2, A.sub.6 = -0.51177 
.times. 10.sup.-3, 
A.sub.8 = 0.25168 .times. 10.sup.-3 
(second mode) 
magnification = -0.6, IO = 35 mm 
effective F number = 8.0 
r.sub.1 = 3.3890 
d.sub.1 = 1.1000 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.2 = 2.1800 (aspherical surface) 
d.sub.2 = 3.6000 
r.sub.3 = .infin. (stop) 
d.sub.3 = 0.2000 
r.sub.4 = 5.0490 
d.sub.4 = 10.8000 
n.sub.2 = 1.48993 
.nu..sub.2 = 57.66 
r.sub.5 = -4.4240 (aspherical surface) 
aspherical surface coefficients 
(2nd surface) 
P = 1.0000, A.sub.4 = -0.16616 .times. 10.sup.-3 
A.sub.6 = -0.11819 .times. 10.sup.-1, A.sub.8 = -0.53512 
.times. 10.sup.-3 
(5th surface) 
P = -2.8000, A.sub.4 = -0.27070 .times. 10.sup.-2 
A.sub.6 = -0.51177 .times. 10.sup.-3, A.sub.8 = 0.25168 
______________________________________ 
.times. 10.sup.-3 
The display member is set at a distance of 30 mm as measured from the film 
surface, an imaging magnification is set at -1.0.times. and the optical 
system has an effective F number of 8.0 in the first mode of the fifth 
embodiment, whereas the display section is set at a distance of 35 mm as 
measured from the film surface, an imaging magnification is set at 
-0.6.times. and the optical system has an effective F number of 8.0 in the 
second mode of the fifth embodiment. Further, the auxiliary lens unit is 
configured as a negative meniscus lens unit having an aspherical surface 
on one side thereof. 
In the fifth embodiment in which the display member 11 is kept fixed, the 
modes are switched from one to the other by moving the main lens unit 13, 
etc. for a distance of 5 mm in parallel with the film surface. 
Though each of the first through fifth embodiments described above is 
configured so as to lower a magnification by switching from the first mode 
to the second mode, it is possible to configure the embodiment so as to 
enhance a magnification by switching from the first mode to the second 
mode. 
FIG. 11 shows a diagram illustrating a concept adopted for a sixth 
embodiment of the photographing apparatus according to the present 
invention which uses an optical system shown in FIG. 12A and FIG. 12B in 
developed conditions (where optical axes are unfolded at the reflecting 
surfaces into a straight line). In these drawings, reference numeral 11 
represents a display member for providing data such as characters, 
reference numerals 21 and 22 designate aperture stops, reference numerals 
23 and 24 denote imaging lens systems, reference numeral 15 represents a 
film surface, reference numerals 25 and 26 designate axes of optical paths 
leading from the display member 11 to the film surface, and reference 
numerals 23a and 24a denote reflecting surfaces. Out of these members, the 
display member 11, the aperture stop 21, the imaging lens system 23, the 
film surface 15, the optical axis 25 and the reflecting surface 23a are to 
be used in a first mode of the sixth embodiment, whereas the display 
member 11, the aperture stop 22, the imaging lens system 24, the film 
surface 15, the optical axis 26 and the reflecting surface 24a are to be 
employed in a second mode of the sixth embodiment. Each of the imaging 
lens systems to be used in the first mode and the second mode of the sixth 
embodiment is a prism-shaped lens component which is integrally molded so 
as to have the reflecting surface 23a or 24a as well as a curved surface 
of incidence and a curved surface of emergence having imaging functions. 
The imaging lens system 23 is slightly shorter than the imaging lens 
system 24, and surfaces of incidence of the aperture stop 21 and the 
imaging lens system 23 are disposed at locations which are closer to the 
display member 11 than locations at which surfaces of incidence of the 
aperture stop 22 and the imaging lens system 24 are disposed. Further, the 
two imaging lens systems 23 and 24 have optical axes which are 
substantially in parallel with each other. In the sixth embodiment, the 
optical axes are nearly in parallel with the film surface 15 before they 
reach the reflecting surfaces 23a and 24a of the imaging lens systems 23 
and 24, and the reflecting surfaces 23a and 24a are inclined at an angle 
of about 45.degree. so that data will be projected to the film surface 15 
nearly perpendicularly from either of the optical paths in the first mode 
and the second mode. Though the two imaging lens systems 23 and 24 are 
disposed in a condition where their sides are in contact with each other, 
these lens systems may be molded as an integral member. In either of the 
first and second modes, rays emitted from the display member 11 pass 
through the aperture stop 21 or 22, fall on the imaging lens system 23 or 
24, are reflected by the reflecting surface 23a or 24a, emerge from the 
imaging lens system 23 or 24 and are imaged on the film surface. 
In the sixth embodiment wherein a surface of emergence of the imaging lens 
system 23 is disposed lower than a surface of emergence of the imaging 
lens system 24, data are recorded on the film surface 15 at more central 
locations in the second mode than data recording locations in the first 
mode. The sixth embodiment is configured so as to permit changing angles 
of the reflecting surfaces 23a and 24a, thereby changing angles of optical 
paths which are formed for allowing data to be incident from the imaging 
lens systems 23 and 24 onto the film surface 15. Accordingly, the sixth 
embodiment permits photographing characters and other data from an 
adequate location which constitutes no hindrance to a photographing light 
bundle for a photographic lens system. However, it is necessary to allow a 
light bundle to be incident at an adequate angle onto the film surface 15 
since images of the characters may be deformed or partially deviate from a 
depth of field and blurred when the light bundle is incident onto the film 
surface 15 at an angle which is too large. 
Further, the sixth embodiment uses a single display member which is 
disposed nearly in the middle between the two aperture stops 21 and 22. 
Accordingly, optical paths 25 and 26 are inclined with regard to the 
optical axes of the imaging lens systems 23 and 24 respectively, whereby 
the sixth embodiment uses an optical system which is eccentric as a whole. 
Speaking concretely, the optical axis of the imaging lens system 23 is 3 
mm apart from the optical axis of the imaging lens system 24 and the 
display member 11 is disposed in the middle between the imaging lens 
systems. In case of this composition, a light bundle coming from the 
display member may be eclipsed by either of the imaging lens systems when 
distances as measured from the display member 11 to the imaging lens 
systems 23 and 24 respectively are largely different from each other. In 
FIG. 11, a light bundle to be incident on the imaging lens system 24 may 
be eclipsed by the imaging lens system 23. Such an eclipse can be 
prevented simply by increasing a distance reserved between the two imaging 
lens systems 23 and 24, but such a preventive measure will pose problems 
that enlargement of the optical system, may make correction of aberration 
difficult resulting in images of characters being badly deformed due to 
oblique intersection of the optical paths of center axes of the optical 
system with the film surface. To solving these problems, the surfaces of 
incidence of the imaging lens systems 23 and 24 are disposed as close as 
possible to each other, or within a deviation of 5 mm, in the optical 
system according to the present invention. 
In the sixth embodiment, each of the imaging lens systems is composed of a 
single biconvex lens component which has an aspherical surface of 
emergence. This aspherical surface serves to correct spherical aberration 
and coma. 
The sixth embodiment has, in the first mode thereof, a distance (IO) of 30 
mm as measured from the display member to the film surface, an imaging 
magnification of -1.0.times. and an effective F number of 8.0 in the first 
mode thereof; and, in the second mode, a distance IO of 35 mm, and imaging 
magnification of -0.7.times. and an effective F number of 6.5 by using the 
aperture stop which is employed in the first mode. Since light intensity 
is enhanced in the second mode due to the employment of the common 
aperture stop between the first mode and the second mode, it is proper to 
lower the light intensity in the second mode by selecting a modified 
exposure time, using an additional ND filter or mixing a dye with a 
material which is to be used for fabricating the imaging lens system 24. 
The sixth embodiment has numerical data listed below: 
______________________________________ 
Embodiment 6 
______________________________________ 
(first mode) 
magnification = -0.1, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = display member 
d.sub.1 = 10.85 
r.sub.2 = .infin. (stop) 
d.sub.2 = 0.20 
r.sub.3 = 5.466 
d.sub.3 = 7.85 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.4 = -4.495 (aspherical surface) 
d.sub.4 = -5.387 
r.sub.5 = film surface 
aspherical surface coefficients 
(4th surface) 
P = 0.5549, A.sub.4 = 1.6133 .times. 10.sup.-3, A.sub.6 = -1.8499 .times. 
10.sup.-4, 
A.sub.8 = 4.0395 .times. 10.sup.-5 
(second mode) 
magnification = -0.7, IO = 35 mm 
effective F number = 6.5 
r.sub.1 = display member 
d.sub.1 = 13.63 
r.sub.2 = .infin. (stop) 
d.sub.2 = 0.20 
r.sub.3 = 9.679 
d.sub.3 = 10.07 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.4 = -4.495 (aspherical surface) 
d.sub.4 = 11.10 
r.sub.5 = film surface 
aspherical surface coefficients 
(4th surface) 
P = 0.1892, A.sub.4 = 3.7695 .times. 10.sup.-4 
A.sub.6 = -3.7892 .times. 10.sup.-5, A.sub.8 = 9.9434 .times. 10.sup.-6 
______________________________________ 
In the sixth embodiment, the imaging lens systems 23 and 24 may be disposed 
separately, cemented to each other or molded as an integral member. For 
switching between the first and second photographing modes, it is possible 
to equip the aperture stops 21 and 22 with shutter mechanisms or dispose 
separate shutter mechanisms S.sub.1 and S.sub.2, for example, in the 
vicinities of surfaces of emergence of the imaging lens systems. Shutter 
mechanisms can easily be disposed in the sixth embodiment in which the 
distance as measured from the surface of emergence to the film surface 
remains unchanged between the first mode and the second mode. The 
switching between the first mode and the second mode can be performed by 
exchanging the right side section with the left side section. Further, it 
is preferable from a viewpoint of manufacturing cost to configure the 
reflecting surfaces 23a and 24a as totally reflecting surfaces. 
FIG. 13 shows a perspective view descriptive of a concept adopted for a 
seventh embodiment of the photographing apparatus according to the present 
invention which uses an optical system shown in FIG. 14A and FIG. 14B in 
developed conditions thereof. In FIG. 13, reference numeral 11 represents 
a display member, reference numerals 21 and 22 designate aperture stops, 
reference numerals 23 and 24 denote imaging lens systems, reference 
numeral 15 represents a film, reference numerals 25 and 26 designate 
optical axes, and reference numerals 23a and 24a denote reflecting 
surfaces. 
The seventh embodiment is free from eccentricity since the optical axes of 
the imaging lens systems 23 and 24 are coincident with center axes of the 
optical system used in this embodiment. Two imaging lens systems 23 and 24 
are disposed in a direction along the thickness of a camera body. In other 
words, the imaging lens system 23 and the imaging lens system 24 are 
disposed so that one is placed on the other in a vertical direction. In 
the seventh embodiment also, the imaging lens systems 23 and the imaging 
lens system 24 may be molded integrally so as to have the reflecting 
surfaces 23a and 24a as well as portions rising above the reflecting 
surfaces and other portions extending from the reflecting surfaces toward 
the film surface. The rising portion and the extending portion of the 
imaging lens system 23 are shorter than those of the imaging system 24. 
Further, a distance as measured from the film to a surface of emergence of 
the imaging lens system 23 is longer than a distance as measured from the 
film to a surface of emergence of the imaging lens system 24. The optical 
axes of these two imaging lens system are nearly parallel with each other 
like the case of the sixth embodiment of the present invention. The 
seventh embodiment is configured so as to perform switching of the 
photographing modes by moving the display member 11. Accordingly, 
characters and other data are moved in a direction along a shorter side of 
the film in conjunction with the movement of the display section 11. When 
two display members are prepared, the photographing modes can be switched 
by selectively glowing the display members. 
The seventh embodiment has numerical data which are listed below: 
______________________________________ 
Embodiment 7 
______________________________________ 
(first mode) 
magnification = -1.0, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = display member 
d.sub.1 = 9.15 
r.sub.2 = .infin. (stop) 
d.sub.2 = 0.20 
r.sub.3 = 6.031 
d.sub.3 = 9.73 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.4 = -4.313 (aspherical surface) 
d.sub.4 = 10.92 
r.sub.5 = film surface 
aspherical surface coefficients 
(4th surface) 
P = 0.4979, A.sub.4 = 1.4033 .times. 10.sup.-3 
A.sub.6 = -4.5822 .times. 10.sup.-4, A.sub.8 = 1.9361 .times. 10.sup.-4 
(second mode) 
magnification = -0.7, IO = 35 mm 
effective F number = 5.7 
r.sub.1 = display member 
d.sub.1 = 13.90 
r.sub.2 = .infin. (stop) 
d.sub.2 = 0.20 
r.sub.3 = 5.245 
d.sub.3 = 12.96 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.4 = -4.999 (aspherical surface) 
d.sub.4 = 7.94 
r.sub.5 = film surface 
aspherical surface coefficients 
(4th surface) 
P = -0.1002, A.sub.4 = 1.5806 .times. 10.sup.-3 
A.sub.6 = -7.7505 .times. 10.sup.-4, A.sub.8 = 4.2236 .times. 10.sup.-4 
______________________________________ 
In the first mode of the seventh embodiment, a distance as measured from 
the display member to the film surface is kept at 30 mm, an imaging 
magnification is set at -1.0.times. and the optical system has an 
effective F number of 8.0. In the second mode, the distance as measured 
from the display member to the film surface is changed to 35 mm, the 
imaging magnification is modified to -0.7.times. and the optical system 
has an effective F number of 5.7 since the aperture stops 21 and 22 have 
the same size. 
Each of the imaging lens systems 23 and 24 is formed of a single biconvex 
lens component as shown in FIG. 14A and FIG. 14B, and has an aspherical 
surface on a side of emergence therefrom. The imaging lens systems 23 and 
24 are members which are quite different from each other. 
FIG. 15 shows a perspective view illustrating a concept adopted for an 
eighth embodiment of the present invention which uses an optical system 
shown in developed conditions in FIG. 16A and FIG. 16B. In these drawings, 
reference numeral 11 represents a display member, reference numerals 21 
and 22 designate aperture stops, reference numerals 23 and 24 denote 
imaging lens systems, reference numeral 15 represents a film, reference 
numerals 25 and 26 designate optical axes, and reference numeral 27 denote 
an auxiliary lens unit. 
In the eighth embodiment, the aperture stop 22 which is to be used in a 
second mode has an aperture smaller than that of the aperture stop 21 
which is to be used in a first mode so that the optical system has an F 
number which remains unchanged between the first mode and the second mode. 
This optical system is eccentric like that used in the sixth embodiment of 
the present invention. 
In the first mode of the eighth embodiment, a light bundle emitted from the 
display member 11 is allowed to pass through the aperture stop 21, falls 
on the imaging lens system 23, emerges from the imaging lens system 23 and 
is imaged onto the film 15. In the second mode, on the other hand, the 
light bundle is allowed to pass through the auxiliary lens unit 27 after 
emerging from the imaging lens system 24 and is imaged onto the film 15. 
The eighth embodiment, which uses no reflecting surface, is configured so 
as to image straightly the display member 11 disposed before the film 15. 
Further, the eighth embodiment uses the display member 11 commonly between 
the first mode and the second mode while it is kept fixed. The optical 
axis 25 is 3 mm apart from the optical axis 26. 
The optical system adopted for the eighth embodiment has the following 
numerical data: 
______________________________________ 
Embodiment 8 
______________________________________ 
(first mode) 
magnigication = -1.0, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = display member 
d.sub.1 = 11.32 
r.sub.2 = .infin. (stop) 
d.sub.2 = 0.20 
r.sub.3 = 6.050 
d.sub.3 = 6.66 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.4 = -5.427 (aspherical surface) 
d.sub.4 = 11.82 
r.sub.5 = film surface 
aspherical surface coefficients 
(4th surface) 
P = 0.5512, A.sub.4 = 1.7587 .times. 10.sup.-3 
A.sub.6 = -2.1356 .times. 10.sup.-4, A.sub.8 = 4.5908 .times. 10.sup.-5 
(second mode) 
magnification = -0.7, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = display member 
d.sub.1 = 11.32 
r.sub.2 = .infin. (stop) 
d.sub.2 = 0.20 
r.sub.3 = 6.050 
d.sub.3 = 6.66 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.4 = -5.427 (aspherical surface) 
d.sub.4 = 2.31 
r.sub.5 = 86.785 
d.sub.5 = 5.65 
n.sub.1 = 1.48993 
.nu..sub.2 = 57.66 
r.sub.6 = -7.207 (aspherical surface) 
d.sub.6 = 3.86 
r.sub.7 = film surface 
aspherical surface coefficients 
(4th surface) 
P = 0.5512, A.sub.4 = 1.7587 .times. 10.sup.-3 
A.sub.6 = -2.1356 .times. 10.sup.-4, A.sub.8 = 4.5908 .times. 10.sup.-5 
(6th surface) 
P = 0.9559, A.sub.4 = 8.8525 .times. 10.sup.-4 
A.sub.6 = -3.4920 .times. 10.sup.-4, A.sub.8 = 5.7362 .times. 10.sup.-5 
______________________________________ 
In the first mode of the eighth embodiment, a distance as measured from the 
display member to a surface of the film is kept at 30 mm, an imaging 
magnification is set at -1.0.times. and the optical system has an 
effective F number of 8.0, as in the case of sixth embodiment. In the 
second mode of eighth embodiment, the distance as measured from the 
display member to the film surface is kept at 30 mm, the imaging 
magnification is changed to 0.7.times. and the effective F number of the 
optical system remains unchanged from 8.0. Further, each of the imaging 
lens systems and the auxiliary lens unit is composed of a single biconvex 
lens component which has an aspherical surface on the side of emergence 
therefrom. Furthermore, the imaging lens system 23 is quite the same as 
the imaging lens system 24. 
FIG. 17 shows a perspective view illustrating a concept adopted for 
configuring a ninth embodiment of the represent invention which uses an 
optical system illustrated in developed conditions in FIG. 18A and FIG. 
18B. In FIG. 17, reference numeral 11 represents a display member, 
reference numerals 21 and 22 designate aperture stops, reference numerals 
23 and 24 denote imaging lens systems, reference numeral 15 represents a 
film, reference numerals 25 and 26 designate optical axes, and reference 
numerals 23a and 24a denote reflection surfaces. 
In the ninth embodiment, the imaging lens system 23 which is to be used in 
a first mode has a surface of emergence formed as a side surface thereof 
and the imaging lens system 24, which is to be used in a second mode, has 
a surface of emergence formed at a location protruding from a side surface 
thereof so that a distance as measured from a surface of the film 15 to 
the surface of emergence of the imaging lens system 23 is longer than a 
distance as measured from the film surface 15 to the surface of emergence 
of the imaging lens system 24. Further, the aperture stops are disposed on 
the emergence sides of the surfaces of emergence of the imaging lens 
systems and an aperture to be used in the first mode is larger than an 
aperture to be used in the second mode. 
The optical system adopted for the ninth embodiment has numerical data 
listed below: 
______________________________________ 
Embodiment 9 
______________________________________ 
(first mode) 
magnificaiton = -1.0, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = display member 
d.sub.1 = 8.04 
r.sub.2 = 5.599 (aspherical surface) 
d.sub.2 = 11.61 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -3.911 (aspherical surface) 
d.sub.3 = 0.20 
r.sub.4 = .infin. (stop) 
d.sub.4 = 10.15 
r.sub.5 = film surface 
aspherical surface coefficients 
(2nd surface) 
P = 0.0411, A.sub.4 = -2.7233 .times. 10.sup.-4 
A.sub.6 = -5.0896 .times. 10.sup.-5, A.sub.8 = 0 
(3rd surface) 
P = 10.9741, A.sub.4 = 4.0725 .times. 10.sup.-2 
A.sub.6 = -7.3907 .times. 10.sup.-3, A.sub.8 = 0 
(second Mode) 
magnification = -0.7, IO = 35 mm 
effective F number = 8.0 
r.sub.1 = display member 
d.sub.1 = 8.04 
r.sub.2 = 5.599 (aspherical surface) 
d.sub.2 = 18.72 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -3.343 (aspherical surfce) 
d.sub.3 = 0.20 
r.sub.4 = .infin. (stop) 
d.sub.4 = 8.04 
r.sub.5 = film surface 
aspherical surface coefficients 
(2nd surface) 
P = 0.0411, A.sub.4 = -2.7233 .times. 10.sup.-4 
A.sub.6 = -5.0896 .times. 10.sup.-5, A.sub.8 = 0 
(3rd surface) 
P = 3.9617, A.sub.4 = 3.2994 .times. 10.sup.-2 
A.sub.6 = -2.7123 .times. 10.sup.-2, A.sub.8 = 0 
______________________________________ 
In the first mode of the ninth embodiment, a distance as measured from the 
display member to the film surface is kept at 30 mm, an imaging 
magnification is set at -1.0.times. and the optical system has an 
effective F number of 8.0. In the second mode, the distance as measured 
from the display member to the film surface is modified to 35 mm, the 
imaging magnification is changed to -0.7.times. and the effective F number 
of the optical system is kept at 8.0. Further, each of the imaging lens 
systems is composed of a single biconvex lens component as shown in FIG. 
18A and FIG. 18B, and has aspherical surfaces on both sides thereof. 
Surfaces of incidence of these two imaging lens systems are formed as a 
single surface as illustrated in FIG. 17, and each of optical axes 25 and 
26 of the imaging lens systems is eccentric from the surface of incidence. 
FIG. 19 is a perspective view showing a concept selected for a tenth 
embodiment of the present invention which uses an optical system 
illustrated in developed conditions in FIG. 20A and FIG. 20B. In these 
drawings, reference numeral 11 represents a display member, reference 
numerals 21 and 22 designate aperture stop, reference numerals 23 and 24 
denote imaging lens systems, reference numeral 15 represents a film, 
reference numerals 25 and 26 designate optical axes, and reference 
numerals 29 and 30 denote reflecting surfaces. 
In the tenth embodiment, the two imaging lens systems each of which is 
composed of a thick prism-shaped lens component are disposed so as to have 
inclined optical axes, the aperture stops 21 and 22 are disposed on the 
emergence sides of surfaces of emergence of the imaging lens systems, and 
the reflecting surfaces are placed on the emergence sides of the aperture 
stops for leading rays to a surface of the film 15. 
In the tenth embodiment, surfaces of incidence of the imaging lens system 
23 and 24 have the same shape and are disposed at an equal distance as 
measured from the display member. Further, the optical axes of the two 
imaging lens systems intersect with each other at an angle of 17.degree. 
though these optical axes are coincident with center axes of the optical 
system. 
The optical system used in the tenth embodiment has numerical data which 
are listed below: 
______________________________________ 
Embodiment 10 
______________________________________ 
(first mode) 
magnification = -1.0, IO = 30 mm 
effective F number = 8.0 
r.sub.1 = display member 
d.sub.1 = 13.69 
r.sub.2 = 6.510 (aspherical surface) 
d.sub.2 = 2.60 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -6.964 (aspherical surface) 
d.sub.3 = 0.20 
r.sub.4 = .infin. (stop) 
d.sub.4 = 13.51 
r.sub.5 = film surface 
aspherical surface coefficients 
(2nd surface) 
P = 1.0525, A.sub.4 = -3.9126 .times. 10.sup.-4 
A.sub.6 = 0, A.sub.8 = 0 
(3rd surface) 
P = 6.0086, A.sub.4 = 1.0003 .times. 10.sup.-2 
A.sub.6 = -1.9925 .times. 10.sup.-2, A.sub.8 = 1.4302 .times. 10.sup.-2 
(second mode) 
magnification = -0.8, IO = 35 mm 
effective F number = 8.0 
r.sub.1 = display member 
d.sub.1 = 13.69 
r.sub.2 = 6.510 (aspherical surface) 
d.sub.2 = 10.50 
n.sub.1 = 1.48993 
.nu..sub.1 = 57.66 
r.sub.3 = -5.451 (aspherical surface) 
d.sub.3 = 0.20 
r.sub.4 = .infin. (stop) 
d.sub.4 = 10.61 
r.sub.5 = film surface 
aspherical surface coefficients 
(2nd surface) 
P = 1.0525, A.sub.4 = -3.9126 .times. 10.sup.-4 
A.sub.6 = 0, A.sub.8 = 0 
(3rd surface) 
P = 5.9204, A.sub.4 = 1.3579 .times. 10.sup.-2 
A.sub.6 = -4.0463 .times. 10.sup.-2, A.sub.8 = 4.9450 .times. 10.sup.-2 
______________________________________ 
In the first mode of the tenth embodiment, a distance as measured from the 
display member to a surface of the film surface is kept at 30 mm, an 
imaging magnification is set at -1.0.times. and the optical system has an 
effective F number of 8.0. In the second mode, the distance as measured 
from the display member to the film surface is modified to 35 mm, the 
imaging magnification is changed to -0.8.times. and the F number of the 
optical system is kept at 8.0. 
In the tenth embodiment, each of the imaging lens systems is composed of a 
single biconvex lens component having aspherical surfaces on both sides 
thereof. 
Though each of the embodiments of the present invention is configured so as 
to have a magnification which is enhanced by switching from a first mode 
to a second mode, it is possible to configure the embodiment so as to have 
a magnification which is lowered by switching from the first mode to the 
second mode. 
The aspherical surfaces used in the embodiments described above have shapes 
which is expressed by the following formula: 
##EQU1## 
wherein the z axis is taken as a direction in which rays travel along an 
optical axis, the y axis is taken as a direction perpendicular to the 
optical axis, the reference symbol r represents a paraxial radius of 
curvature, and the reference symbols p, A.sub.4, A.sub.6 and A.sub.8 
designate aspherical surface coefficients. 
In the numerical data of the embodiments of the present invention, the 
reference symbols r.sub.1, r.sub.2, . . . represent radii of curvature on 
respective lens surfaces, the reference symbols d.sub.1, d.sub.2, . . . 
designate airspaces reserved between the respective lens surfaces, the 
reference symbol n denotes a refractive index of a lens component at a 
wavelength of 655 nm, and the reference symbol .nu. represents an Abbe's 
number for the d-line. Though the lens components used in all the 
embodiments are made of acrylic resin materials which are apt to be 
influenced by variations of temperature and humidity, it is possible to 
make the lens components of low hygroscopic materials for preventing 
influences due to variations of humidity. 
The first mode and the second mode of each of the embodiments are 
illustrated separately. The display members 11 are used commonly between 
the first modes and the second modes, though they are traced at locations 
which are different from each other between FIG. 8A, FIG. 10A illustrating 
the first modes, and FIG. 8B, FIG. 10B illustrating the second modes among 
the development views of the optical systems used in the third embodiment 
and the fourth embodiment. The locations of the film surfaces are kept 
fixed as shown in FIG. 13, FIG. 17 and FIG. 19, though the locations are 
traced differently between FIG. 12A, FIG. 14A, FIG. 18A, FIG. 20A 
illustrating the first modes of the sixth, seventh, ninth and tenth 
embodiments, and FIG. 12B, FIG. 14B, FIG. 18B and FIG. 20B illustrating 
the second modes thereof. LED's or illuminated LCD's are usable as display 
members in the optical systems according to the present invention. 
Further, optical paths are made of plastic materials. 
The data recording optical system according to the present invention is 
capable of recording characters and other data without fail in natural 
sizes and at natural locations regardless of variations of film sizes.