JP3109765B2 - Film unit with lens - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lens-equipped film unit in which an unexposed film is built in advance.

[0002]

2. Description of the Related Art A lens-fitted photo film unit widely sold by the present applicant (such as "Sharun")
Are sold in a state in which an unexposed film is previously loaded in a unit main body incorporating a simple photographing mechanism and a winding mechanism, and are collected together with the unit main body after use.
After disassembly of the unit main body at the developing laboratory, the exposed film is taken out and subjected to development and print processing, but the unit main body itself is not returned to the user. From such a background, a dedicated film can be used as the film built in the film unit with a lens.

[0003] A film built into a conventional film unit with a lens is a 135 type color negative film defined by international standards. The color negative film is provided with various sensitivities so that it can be mounted on any camera and depending on the use of the photographer. A general-purpose color negative film has a structure in which each of the light-sensitive layers in the blue, green, and red light-sensitive areas is a blue light-sensitive layer, a green light-sensitive layer, and a red light-sensitive layer in order from the exposed surface. Each has a different spectral sensitivity characteristic. A silver iodobromide emulsion is generally used as a silver halide used as a constituent material of these photosensitive layers, and has a high sensitivity to blue light. For this reason, a sensitizing dye is added during the production of the emulsion, or a yellow filter layer that absorbs blue light is provided below the blue-sensitive layer to keep the sensitivity balance of each photosensitive layer constant.

[0004]

As described above, the above-mentioned film unit with lens incorporates a color negative film which has been subjected to a process for keeping the sensitivity balance of each photosensitive layer constant. For this reason, there is a disadvantage that the cost of the color negative film is high due to the processing for keeping the sensitivity balance of each photosensitive layer constant, and the cost is reflected in the price of the film unit with the lens.

The present invention has been made in view of the above background, and has as its object to provide a low-cost film unit with a lens in which a low-cost color negative film is incorporated.

[0006]

In order to achieve the above object, a film unit with a lens according to the present invention comprises a photosensitive layer.
Of the green photosensitive layer and the red photosensitive layer have substantially the same specific sensitivity,
In addition, the specific sensitivity of the blue photosensitive layer is 1.6 to 4 more than the other photosensitive layers.
Built-in photo film which is twice as high as before,
It also compensates for the different specific sensitivities of the photosensitive layers of the photographic film.
Shooting light through a shooting lens or filter with light transmission characteristics
It is provided fixed on a shaft .

[0007]

[0008]

FIG. 2 shows the appearance of a film unit with a lens. In FIG. 2, a unit main body 1 includes a main body 2 made of plastic and a back cover 3 for closing an opening on the back side of the main body 2 in a light-tight manner. Consists of The main body 2 is provided with a photographing lens 4, a finder window 5, a release button 6, and a film winding dial 8 which are formed of glass. The release button 6 is provided inside as shown in FIG.
And a film taking mechanism (not shown) such as a film winding mechanism (not shown) interlocked with the operation of the film winding dial 8. The back cover 3 is fixed to the back side of the main body 2, and a film 12 with a patrone is light-tightly accommodated therebetween as shown in FIG. 1.

The film 12 with a patrone is composed of a patrone 13 for storing a 35 mm wide film 14 in a light-shielded state at the time of assembly and a roll-shaped film 14 pulled out from the patrone 13 in the main body 2. The film roll chamber 15, with the exposure frame 17 provided therebetween,
And in the patrone chamber 16 respectively. The film 12 with a patrone used here is a 135 type color negative film defined by international standards.

As shown in FIG. 3, the film 14 comprises a blue-sensitive layer 20, a green-sensitive layer 21, and a red-sensitive layer 2 having different spectral sensitivity characteristics.
2 and the photosensitive layers 20, 2
The specific sensitivity of the blue-sensitive layer 20 of the photosensitive layers 21 and
22 is a film dedicated to a film unit with a lens different from 22. This is because each photosensitive layer 20,
This is a low-cost type film manufactured without performing processing for keeping the balance between the sensitivities of the photosensitive layers 21 and 22 constant. The blue-sensitive layer 20 has a higher sensitivity than the other photosensitive layers 21 and 22. It should be noted that the specific sensitivity of the blue-sensitive layer 20 was changed to the other photosensitive layer 2.
It is preferable to manufacture the film 14 in a state where the film 14 is higher than the films 1 and 22 since the blue-sensitive layer 20 is applied to the most exposed surface of the film 14 because the film 14 is relatively easily processed.

The sensitivity of the photosensitive layers 20, 21, 22 with respect to the sensitivity of the film 14 will be described. For example,
With the sensitivity of the film 14 "ISO100", each photosensitive layer 2
The sensitivity of 0, 21, 22 is as shown in Table 1.

[0012]

[Table 1]

For example, the sensitivity of the film 14 "ISO2
00 ”, the sensitivities of the respective photosensitive layers 20, 21, 22 are as shown in Table 2.
It is shown as below.

[0014]

[Table 2]

Further, for example, the sensitivity of the film 14 "IS
In "O400", the sensitivity of each of the photosensitive layers 20, 21, 22 is as shown in Table 3.

[0016]

[Table 3]

Note that ANSI (American National Standards)
(Institute, Inc.) standard specifies that the sensitivity of the film 14 is determined based on the specific sensitivity between the green-sensitive layer and the red-sensitive layer. Therefore, as shown in Tables 1 to 3, The specific sensitivity of the green-sensitive layer 21 and that of the red-sensitive layer 22 are substantially the same, and the specific sensitivity of the blue-sensitive layer 20 is 1.
Even with the film 14 of 6 times to 4 times, the specific sensitivity of the green sensitive layer 21 and the red sensitive layer 22 can be displayed as the sensitivity of the film 14 as it is.

Behind the taking lens 4, a filter 24 is provided. The filter 24 has a spectral transmission characteristic such that light is reduced in the wavelength region of the blue-sensitive layer 20 as shown in FIG. 4 in order to compensate for different specific sensitivities of the blue-sensitive layer 20. In addition, as a material of the filter 24, a gelatin filter, an interference filter, and the like may be used in addition to the glass filter and the plastic filter. Further, if the sensitivity of each of the photosensitive layers 20, 21, and 22 described above is determined based on any of the industrial standards of photographic photosensitive materials in various countries around the world, a filter having a spectral transmission characteristic that compensates for these sensitivities. 24 can be easily made.

Next, the operation of the lens-fitted film unit will be briefly described. When the release button 6 is operated, the shutter of the shutter mechanism 11 opens and closes, and the subject light transmitted through the photographing lens 4 transmits through the filter 24,
4 is incident on the film 14 located on the exposure frame 17 and exposure is performed.

The subject light that has passed through the filter 24 is incident on the film 14 after being attenuated in a wavelength range of about 300 to 500 nm as shown in FIG. 4, and the spectral sensitivity characteristics of the film 14 are shown in FIG. As described above, the blue-sensitive layer 20, which is sensed in the wavelength range of about 300 to 500 nm, has a higher specific sensitivity than the other photosensitive layers 21 and 22, so that it is appropriate in terms of color sensitivity. Thereafter, when the winding knob 8 is rotated, the exposed film is wound into the cartridge 13. At the same time, the next film frame is supplied to the position of the exposure frame 17 and fed one frame at a fixed length.

By repeating photographing in this manner, the exposed film is sequentially rolled up in the cartridge 13. And after completing the shooting,
Submitted to the lab as is. When processing is carried out in a developing laboratory, the photographed cartridge can be taken out in the same state as before, and thereafter, the film development and print processing can be performed by the same processing as before.

It is known that if the color development of blue is strengthened with respect to red and green, the color of the finished print photograph will appear to be tight, but the spectral characteristics of the filter 24 are adjusted in consideration of this. You can also put it.

In the above-described embodiment, the filter 2
4 is provided separately from the photographing lens 4, but instead of the filter 24, the photographing lens 4 is coated,
The taking lens 4 itself may have a spectral transmission characteristic as shown in FIG. If the material of the taking lens 4 is made of plastic, a taking lens having the same role as the filter 24 can be integrally molded. In this case, a spectral transmission characteristic as shown in FIG.
It may be molded by coloring with a dye such as a cellulose dielectric or an acrylic resin.

[0024]

As described in detail above, according to the film unit with a lens of the present invention, the specific sensitivity of the green sensitive layer and the red sensitive layer among the photosensitive layers is substantially the same, and The specific sensitivity of the photosensitive layer in the range of 1.6 to 4 times higher than that of the other photosensitive layers, and fix the photographing lens or filter having the spectral transmission characteristic to compensate for the different specific sensitivity on the photographing optical axis. set <br/> only with a taking lens, or it is so arranged to photograph through a filter, to facilities processing for a constant balance between the sensitivity of the photosensitive layer during film production as film to incorporate
There is no need to use a low-cost dedicated
Lum can be used . Therefore, it is possible to lower cost of the lens-fitted photo film unit itself.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a film unit with a lens according to 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 a relationship between a spectral sensitivity characteristic of a built-in film and a specific sensitivity.

FIG. 4 is a graph showing a spectral transmission characteristic of a filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film unit with lens 4 Photographing lens 12 Film with patrone 13 Patrone 14 Film 24 Filter

Claims (1)

(57) [Claims] (1) a blue-sensitive layer and a green color
A light-sensitive layer and a red light-sensitive layer
Film camera with a built-in color photo film
In the knit, the photographic film includes a green photosensitive layer and a red photosensitive layer among the photosensitive layers.
The specific sensitivity with the photosensitive layer is almost the same, and the specific sensitivity of the blue photosensitive layer is
Degree is 1.6 to 4 times higher than other photosensitive layers.
And different ratios of the photosensitive layers of the photographic film.
Photographic lens or filter with spectral transmission characteristics that compensate for the degree
A film unit with a lens fixed on the photographing optical axis .