JP4065934B2 - Autofocus device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an autofocus device that detects the position of a film surface and moves the film surface to a predetermined position.
[0002]
[Prior art]
As is well known, there are two types of apparatuses for printing a film image on photographic paper, dedicated to negative film and dedicated to positive film. This is because the negative film and the positive film have completely different characteristics of the projected image, and the photographic paper and the developer are completely different.
[0003]
For example, as shown in FIG. 2, the apparatus dedicated to the positive film includes a light source 501, a yellow (Y), magenta (M), and cyan (C) three-complementary color filter 504, an autofocus device 550, and a lens unit 509. , A shutter 502 and a magazine 510 for sending out the photographic paper X one frame at a time. As the lens unit 509, a fixed focus lens or a variable focal length variable focus lens is used. Further, although not shown in the drawing, image density information of the three primary colors of blue (B), green (G), and red (R) is displayed at an appropriate position below the autofocus device 550 in order to perform printing. An optical sensor (for example, a photodiode) for detection is provided, and the average transmission density LATD (Large Area Transmittance Density) of the positive film is measured.
[0004]
As shown in FIG. 3, the autofocus device 550 includes a positive film mount 507 that holds a positive film 508, a mount carrier 505 that detachably supports the positive film mount 507 via a V guide 506, and a mount carrier 505. A carrier frame 505 ′ to be supported, two guide rods (not shown) which are arranged in parallel with the optical axis of the lens unit 509 and slidably support the carrier frame 505 ′, and the carrier frame 505 ′ are moved up and down. And a driving unit 520. Furthermore, the autofocus device 550 includes a lamp 511 having a thin linear filament that emits infrared light on an incident light path oblique to the positive film 508, and an infrared transmission filter 512 that allows only light from the linear filament to pass therethrough. And a light emitting side lens 513 for condensing the infrared ray on the positive film 508, a light receiving side lens 514 for condensing the infrared image on the light receiving optical path, and an infrared transmission filter for allowing only the infrared ray of the image to pass therethrough. 515 and a pair of photoconductive elements 516 for detecting the infrared rays of the linear filament.
[0005]
In the drive unit 520, as shown in FIG. 4, a screw shaft 525 is provided in parallel between the two guide rods. The upper end of the screw 525 is fixed to the carrier frame 505 ′, and the lower end portion of the screw shaft is screwed with a female screw 527 formed on the inner periphery of the sleeve 526. A male screw 528 is formed on the outer periphery of the sleeve 526, and the male screw 528 is screwed into a screw hole 530 provided in the fixing member 529. A gear 531 is provided at the upper end of the sleeve 526, and a transmission gear 534 is provided between the gear 531 and a drive gear 533 driven by the motor 532. When the sleeve 526 is rotated by driving the motor 532, the sleeve 526 moves with respect to the main body frame 529 and the screw shaft 525 moves with respect to the sleeve 526 in a direction opposite to the moving direction of the sleeve 526. For this reason, the mount carrier 505 moves relative to the lens unit 509 by an amount obtained by subtracting the moving amount of the screw shaft 525 from the moving direction of the sleeve 526.
[0006]
The autofocus device having such a configuration operates as follows.
[0007]
First, the positive film mount 507 is set on the mount carrier 505. At a suitable time before and after the LATD measurement, the lamp 511 of the autofocus device 550 is turned on to generate infrared rays of the linear filament image, and the positive film 508 is irradiated through the infrared transmission filter 512 and the light emitting side lens 513. . As shown in FIG. 3, the infrared light forms an image on the positive film 508, passes through the light receiving side lens 514 and the infrared filter 515, and is received by the photoconductive element 516.
[0008]
When the film surface is bent, the position where the infrared image incident on the positive film 508 is deflected deviates from the center of the film depending on the deflection direction and the deflection amount. For example, if the film surface is bent upward and convex, the filament image is formed at point A, and if it is bent downward, it is formed at point B. The filament images formed at points A and B are formed on the photoconductive element 516 at positions shifted from the reference point O ′ by points A ′ and B ′, respectively.
[0009]
When the image on the photoconductive element 516 deviates from the reference point O ′ in the direction A ′ (that is, when the film bends upward), the motor 532 rotates forward. As a result, the mount carrier 505 is lowered and the image on the film surface moves to the reference point O side, so that the image moves to the reference point O ′ on the photoconductive element 516. When the image is formed at the reference point O ′, the motor 532 stops. When the image on the photoconductive element 516 is shifted from the reference point O ′ in the direction B ′ (that is, when the film bends downward), the motor 532 rotates in the reverse direction. Along with this, the mount carrier 505 rises, the image on the film surface moves to the reference point O side, the image also moves on the photoconductive element 516 to the reference point O ′, and the image on the photoconductive element 516 becomes the reference point. When the image is formed at the point O ′, the motor 532 stops.
[0010]
In this way, the defocus of the image printed on the photographic paper due to the deflection of the film surface is automatically corrected.
[0011]
[Problems to be solved by the invention]
By the way, in recent years, a method has been adopted in which an image on a film is read by a CCD or the like, the image data is taken in, and the image is printed on photographic paper based on the image data, regardless of whether it is a negative film or a positive film. is doing. In this case, the image data obtained from the negative film or the image data obtained from the positive film can be processed to share the characteristics of both image data. Photographic paper and developer can be used, and both a negative film device and a positive film device are not required, and one device can be used in time.
[0012]
In such an apparatus for both negative film and positive film, an auto negative mask for exposing the photographic paper while carrying the negative film and a positive film are accommodated to expose the photographic paper. The auto mount carrier is replaced, and both baking from negative film and baking from positive film are performed.
[0013]
In this case, it is necessary to reduce the size of the auto mount carrier for the positive film to the same extent as the auto negative mask for the negative film. For example, an attempt has been made to omit the portions corresponding to the carrier frame 505 ′ and the main body frame 529 and to move up and down while holding the positive film mount 507 in the mount carrier 505. As a result, it is possible to reduce the size and weight, simplify the configuration, reduce costs, and the like.
[0014]
Furthermore, it is desirable to store the autofocus device in the mount carrier 505. However, in the autofocus device, since the space between the lamp 511 and the photoconductive element 516 and the mount carrier 505 is large, the entire autofocus device cannot be accommodated in the mount carrier.
[0015]
Therefore, the present invention is to provide an autofocus device that can be miniaturized.
[0016]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an autofocus device according to the present invention is provided inside an automount carrier in which a mount holder on which a positive film mount that supports a positive film is placed is provided. An autofocus device that automatically corrects a focus shift caused by a deflection of the film surface, the light source disposed on one side of the mount holder, and the lower side of the mount holder, A first optical means for emitting light emitted from a light source so as to be reflected at the film surface at a predetermined incident angle so as to be reflected by the film surface; and disposed on the other side of the mount holder. And a photoelectric conversion element disposed below the mount holder and emitted from the first optical means on the film surface. A second optical means for incident Isa the light to the photoelectric conversion elements, and having a drive unit for lifting the mounting holder based on the light received by the photoelectric conversion element.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings.
[0019]
FIG. 1 is a side view showing an embodiment of an autofocus device of the present invention. In the figure, an automount carrier 11 is provided with a mount holder 12 supported so as to be movable up and down at an upper limit, and a drive unit 13 for raising and lowering the mount holder 12. The positive film mount 14 is placed on the mount holder 12, and the mount holder 12 is moved up and down by the drive unit 13 to control the position of the film surface of the positive film mount 14. The mount holder 12 is provided with a mount feed claw 15, and the positive film mount 14 is sent to the mount holder 12 by the mount feed claw 15 and arranged.
[0020]
In the automount carrier 11, a light source 16, a first reflecting mirror 17, a second reflecting mirror 18, and a light receiving unit 19 are disposed. The light source 16 is configured by housing a lamp 21 having a thin linear filament that emits infrared rays, an infrared transmission filter 22, a light emitting side lens 23, and the like in a cylindrical body 24. The light receiving unit 19 includes a photoconductive element 25, an infrared transmission filter 26, and a light receiving side lens 27 in a cylindrical body 28.
[0021]
In the light source 16, infrared light emitted from the linear filament of the lamp 21 is emitted through the infrared transmission filter 22 and the light emitting side lens 23. The infrared light emitted from the light source 16 is reflected by the first reflecting mirror 17 and enters the film surface of the positive film mount 14, and the linear filament of the lamp 21 is imaged on the film surface. The infrared light reflected by the film surface is further reflected by the second reflecting mirror 18 and enters the light receiving unit 19.
[0022]
In the light receiving unit 19, the infrared light reflected by the second reflecting mirror 18 passes through the infrared transmission filter 26 and enters the photoconductive element 25, and the linear filament of the lamp 21 is bound to the light receiving unit of the photoconductive element 25. Imaged. Similar to the photoconductive element 516 in the conventional apparatus shown in FIG. 3, the photoconductive element 25 has a pair of light receiving portions, and detects a position where the image of the linear filament of the lamp 21 is shifted.
[0023]
In such a configuration, when the film surface of the positive film mount 14 bends in any of the vertical directions and the image on the film surface shifts in the vertical direction, the image of the linear filament of the lamp 21 also in the photoconductive element 25. Since the position is shifted, the position of the linear filament image can be detected by the photoconductive element 25. In response to the output indicating the positional deviation of the linear filament image from the photoconductive element 25, the drive unit 13 moves the mount holder 12 up and down to move the film surface of the positive film mount 14 to a predetermined position.
[0024]
In the present embodiment, the first optical path from the light source 16 to the film surface of the positive film mount 14 is refracted by the first reflecting mirror 17, and the second optical path from the film surface of the positive film mount 14 to the light receiving unit 19 is the first. The light is refracted by the two reflection mirror 18. For this reason, both the distance between the light source 16 and the positive film mount 14 and the distance between the light receiving unit 19 and the positive film mount 14 are shortened, and the space between the light source 16 and the light receiving unit 19 and the positive film mount 14 is reduced. Therefore, as compared with the conventional device shown in FIG. 3 (including the carrier frame 505 ′ and the main body frame 529), the autofocus device as a whole can be significantly reduced in size, and the autofocus device, that is, the light source 16 and the light receiving device. The part 19 and the like can be stored in the automount carrier 11.
[0025]
Further, in the present embodiment, only the mount holder 12 in the automount carrier 11 is raised and lowered, so that the mount carrier 505 and the carrier frame 505 ′ are raised and lowered as compared with the conventional apparatus shown in FIG. The weight of the portion can be extremely light, and the load on the drive unit 13 that raises and lowers the mount holder 12 is extremely small. For this reason, the drive part 13 does not require the intensity | strength and driving force which are the same as the conventional apparatus shown in FIG.
[0026]
In addition, this invention is not limited to the said embodiment, It can deform | transform variously. For example, the first optical path between the light source 16 and the film surface is refracted only once and the second optical path between the film surface and the light receiving unit 19 is refracted only once. However, even if these optical paths are refracted multiple times. good. Further, instead of the reflecting mirror, a prism or the like may be applied, or an optical fiber may be applied. When applying an optical fiber, the respective optical fibers are connected to the light emission side of the light source 16 and the light incident side of the light receiving unit 19, and the optical fiber on the light emission side of the light source 16 is bent to form a first optical path. The second optical path is formed by bending the optical fiber on the incident side.
[0027]
【The invention's effect】
As described above, according to the autofocus device of the present invention, at least one of the first optical path from the light source to the film surface and the second optical path from the film surface to the photoelectric conversion element is refracted. For this reason, the space between the light source and the photoelectric conversion element and the film surface is small, and the autofocus device can be miniaturized and incorporated in the mount carrier for holding the film.
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of an autofocus device of the present invention.
FIG. 2 is a diagram schematically showing a printing apparatus dedicated to a positive film provided with a conventional autofocus device.
FIG. 3 is a diagram schematically showing the conventional autofocus device of FIG. 2;
4 is a diagram schematically illustrating a mount driving unit of the conventional autofocus device of FIG. 3. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Auto mount carrier 12 Mount holder 13 Drive part 14 Positive film mount 15 Mount feed nail | claw 16 Light source 17 1st reflective mirror 18 2nd reflective mirror 19 Light-receiving part

Claims (1)

A mount holder on which a positive film mount for supporting a positive film is placed is provided inside an auto mount carrier, and the focus shift caused by the deflection of the film surface of the positive film is automatically corrected. An autofocus device,
A light source disposed on one side of the mount holder;
A first optical means disposed under the mount holder and configured to emit light emitted from the light source so as to be reflected at the film surface at a predetermined incident angle with respect to the film surface; ,
A photoelectric conversion element disposed on the other side of the mount holder;
A second optical means disposed on the lower side of the mount holder and causing the light emitted from the first optical means and reflected by the film surface to enter the photoelectric conversion element;
An autofocus device comprising: a drive unit that raises and lowers the mount holder based on light received by the photoelectric conversion element.

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