JP3436348B2 - Illumination optical system for film scanner - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film scanner provided with a line-shaped light source extending in a first direction and a condenser for irradiating a photographic film while condensing a light beam from the light source. Illumination optical system.

[0002]

2. Description of the Related Art In a film scanner adopting such an illumination optical system, a light beam emitted from a line light source is narrowed by a light converging means which is usually formed as a cylindrical lens. After being shaped into a line, it is irradiated onto the frame image of photographic film (hereinafter simply referred to as film), and the line-shaped transmitted light transmitted through this film is extended through the imaging optical system in the main scanning direction (first direction). The frame image of the film is converted into a digital image by causing the CCD sensor to receive light and continuously performing this light receiving process in the sub-scanning direction.

[0003]

In such a film scanner, in order to obtain a high quality digital image, the light intensity distribution of the linear irradiation light beam is uniform over the width of the frame image in the first direction. Is desired. The light intensity of the light beam passing near both ends of the linear irradiation light beam decreases. Therefore, in order to make the effective beam width of the irradiation light beam equal to or larger than the width of the frame image, it is necessary to make the lengths of the linear light source and the light collecting means in the first direction considerably large. This has caused bulky structures and increased costs for optical systems.

In view of the above situation, an object of the present invention is to prevent the length of the light source or the light condensing means in the main scanning direction from being unnecessarily increased with respect to the width of the film image frame to be read in the main scanning direction. It is an object of the present invention to provide an illumination optical system for a film scanner having a sufficiently uniform light intensity capable of generating a linear irradiation light beam.

[0005]

In order to solve the above-mentioned problems, a line-shaped light source extending in a first direction and a light-collecting means for irradiating a photographic film while collecting a light beam from this light source are provided. Illumination optical system for film scanner
The light condensing means collects light in both end regions of the light beam of the light source and the first light condensing unit that condenses the light beam from the light source in a second direction orthogonal to the first direction. Smell composed of a second condensing part that condenses in the first direction
In the present invention, the first light condensing unit is a cylindrical carlene.
And the second light collecting portion is
Around the both ends of the cylindrical lens, the cylindrical lens
It is formed as two condensing lenses that are arranged separately from
It is characterized by being.

In such a configuration, the light beam from the light source extending in the first direction, which is the main scanning direction, has a beam width in the second direction as a sub-scanning direction orthogonal to the first direction by the first condensing unit. Is narrowed to form a sharp irradiation light beam in the sub-scanning direction. At the same time, the light in both end regions of this light beam is condensed in the main scanning direction by the second condensing unit, that is, the light is made dense in the main scanning direction, so that the light in both ends of this irradiation light beam in the main scanning direction is It avoids a sudden drop in light intensity. As a result, the effective beam width in the main scanning direction having a predetermined light intensity level becomes large as compared with the conventional illumination optical system including the line light source having the same main scanning direction length.

[0007]

Further, in the configuration of the present invention, the first light collecting portion is formed as a cylindrical lens and the second light collecting portion is formed as a second lens.
Since the condensing lens as the condensing part is arranged as a separate item around both ends of this cylindrical lens , the present invention
According to a preferred embodiment of the present invention, the arrangement of the second condensing unit is adjusted according to the optical characteristics of the light source and the first condensing unit so as to match a predetermined flat irradiation beam with the width of the frame image in the main scanning direction. Will also be possible. Specific examples of the condenser lens include
The light beam incident from the side of the cylindrical lens is
A convex lens that converges in one direction can be used. According to the invention
Other features and advantages of the embodiment will be described below with reference to the drawings.
The explanation will make it clear.

[0009]

[0010]

DETAILED DESCRIPTION OF THE INVENTION Illumination optical system 3 according to the invention.
An example of the film scanner 3 adopting 0 is shown in FIGS.
As a block diagram. The film scanner 3 is incorporated in a silver salt photographic digital printer as an image input unit for acquiring, as digital image data, a frame image of the film 1 developed by a film developing machine (not shown). In addition to the film scanner 3, the silver salt photographic digital printer includes a controller 5 that processes digital image data acquired by the film scanner 3 to create print data, and a frame image on photographic paper 2 based on the print data. A digital printing unit 4 that exposes a corresponding image and a development processing unit 6 that develops the exposed printing paper 2 are provided. The photographic printing paper 2 developed in the development processing section 6 is discharged as a finished print through a drying process.

The digital print unit 4 adopts a fluorescent beam method, and the fluorescent print head 4a mainly scans a phosphor element in which a lens and a color filter are mounted on a phosphor whose emission is controlled by adjusting a grid voltage. It is composed of a red light emitting block (having a red filter attached), a green light emitting block (having a green filter attached), and a blue light emitting block having a blue filter attached) which are arranged in a linear array to form a linear array. Further, a reciprocating mechanism 4b is also provided for scanning the fluorescent print head 4a in the conveying direction of the photographic printing paper 2.

In addition to the illumination optical system 30, the film scanner 3 includes an image pickup optical system 40 and a photoelectric conversion section 50 using a CCD sensor. The controller 5 has
A monitor 5a for displaying various processing information and an operation console 5b for inputting various processing commands are connected. Reference numeral 9 is a film transport mechanism for transporting the film 1 to the film scanner 3, and reference numeral 10 is a photographic paper transport mechanism for pulling out the photographic paper 2 from the paper magazine 2a and sending it to the digital print section 4 and the development processing section 6. Yes, both transport mechanisms are controlled by the controller 5. The photographic printing paper 2 pulled out from the paper magazine 2a is cut by a cutter (not shown) before or after the development processing,
It is in the form of a finished print in which one frame image is output.

The illumination optical system 30 has a first direction (same as the main scanning direction) orthogonal to the transport direction of the film 1.
Reflector 31a as an example of a line light source that extends to the bottom
It is composed of a rod-shaped halogen lamp 31 with a lamp, a dimming filter 32, a cylindrical lens 33 as a condensing means, a diffuser plate 34 and a slit 35 provided immediately before the film 1, and the color distribution and intensity of the light beam from the light source. In addition to adjusting the distribution, the light beam from the rod-shaped halogen lamp 31 is narrowed down in the second direction (which is the same as the sub-scanning direction) which is the film transport direction, and the line-shaped light beam is extremely narrow when viewed from the main scanning direction. Then, the frame image of the film 1 is finally irradiated.

The image pickup optical system 40 for processing the transmitted light beam from the film 2 includes a mirror 41 for changing the direction of projection light,
The lens unit 42 includes a prism 43 that splits the light beam that has passed through the lens unit into three directions. By feeding the film 1 at a predetermined scanning speed by the film transport mechanism 9, the frame image of the film 1 is scanned in the sub-scanning direction, that is, the longitudinal direction of the film.

The photoelectric conversion unit 50 for photoelectrically converting the light beam guided by the image pickup optical system 40 into a charge image as a slit image includes a CCD sensor unit 51, a sample hold (S / H) circuit 52, and an A / D converter. 53, a sensor drive circuit 54 and the like. The CCD sensor unit 51 has the three components separated by the prism 43.
It is composed of three CCD sensors to receive one light beam separately. Each CCD sensor is a line sensor in which a large number (for example, 5000) of CCD elements are arranged in the main scanning direction, that is, the width direction of the film 1, and the sensor drive circuit 54 controls the charge accumulation operation and the charge accumulation time during the main scanning. Is done. The image pickup surface of each CCD sensor is provided with a color filter that passes only the blue component, the red component, and the green component of the light beam, and photoelectrically converts only the blue component, the red component, and the green component, respectively. The sample hold circuit 52 samples and holds each pixel signal output from each CCD sensor to generate an image signal in which each pixel signal is continuous, and the A / D converter 53 constitutes an image signal. Each pixel signal is converted into a digital signal having a predetermined number of bits (for example, 12 bits).

When the frame image on the film 1 is positioned at a predetermined scan position, the frame image reading process is started. The projected light image of the frame image is sequentially read by the CCD sensor unit 51 in the form of being divided into a plurality of slit images as the film 1 is fed by the film transport mechanism 9. That is, each CCD sensor performs the image capturing operation and the image signal reading operation in synchronization with the timing of this sub-scanning by the function of the sensor drive circuit 54 based on the control signal from the controller 5, whereby the frame image is R, It is photoelectrically converted into image signals of G and B color components and sent to the controller 5 as raw digital image data. Such an illumination optical system 3 of the film scanner 3
0, the imaging optical system 40, and the photoelectric conversion unit 50 are controlled by the controller 5.

The illumination optical system 30 will be described in detail with reference to FIGS. 3 and 4. Most of the light beam emitted from the rod-shaped halogen lamp 31 is directed to the cylindrical lens 33 through the dimming filter 32 with the help of the reflector 31a. The cylindrical lens 33 is arranged so that its cylindrical axis coincides with the main scanning direction, and its length is almost the same as that of the rod-shaped halogen lamp 31. As shown in FIG. 4 (a), its cross section is a convex lens shape whose lower surface side is an arc, and converges the light beam incident from the upper surface side to create a sharp line light beam extending in the main scanning direction. That is, the convex lens shape on the lower surface side collects the light beam from the rod-shaped halogen lamp 31 in the sub scanning direction orthogonal to the main scanning direction.
It functions as 3a. Further, as is clear from FIG. 4B, in both end regions of the cylindrical lens 33,
The upper surface side is formed into a convex surface, and the light beam incident on this region is converged on the center side of the cylindrical lens 33 in the main scanning direction. That is, the convex surfaces of the both end regions function as second condensing portions 33b that condense light on both sides of the linear light beam from the rod-shaped halogen lamp 31 so as to face each other in the main scanning direction. The light beam from the vicinity of both ends of the rod-shaped halogen lamp 31 is converged by the action of the second condensing unit 33b, and thus the light intensity of both end regions is increased with respect to the light intensity distribution in the main scanning direction. As a result, the effective beam in the main scanning direction (a light beam having a predetermined light intensity uniformity)
The length is longer than before.

The cylindrical lens 33 is provided with the second condensing portion 33b for condensing in the main scanning direction at both end regions thereof, so that the line light beam emitted over the entire length of the rod-shaped halogen lamp 31 is utilized to the maximum extent. However, since the effective beam width in the main scanning direction is lengthened to irradiate the frame image of the film 1, the size of the illumination optical system 30 in the main scanning direction can be made as compact as possible. In this embodiment, the convex surface of the first light collecting portion 33a is formed on the lower surface side of the cylindrical lens 33, and the convex surface of the second light collecting portion 33b is formed on the upper surface side of the cylindrical lens 33. The convex surface of the first light collecting portion 33a may be formed on the upper surface side of the cylindrical lens 33, and the convex surface of the second light collecting portion 33b may be formed on the lower surface side of the cylindrical lens 33. May be formed on both upper and lower surfaces of the cylindrical lens 33.

The illumination optical system described above with reference to FIGS. 3 and 4.
The stem 30 is the starting technology of the present invention, and is important for the present invention.
The features are shown in FIG.
Is a structure in which the first condensing unit 33a and the second condensing unit 33b are formed separately, and the first condensing unit 133a converges the light beam incident from the upper surface side in the sub-scanning direction and the main scanning direction. The two second condensing portions 133b arranged below both ends of the cylindrical lens 133a are configured as a cylindrical lens that only produces a focused line light that extends to the upper side of the cylindrical lens 133a. It is configured as a convex lens by converging in the scanning direction.
Even in such a configuration, since the light intensity of both end regions of the line light beam emitted from the rod-shaped halogen lamp 31 is increased by the action of the second light condensing unit 133, compared to the conventional illumination optical system, the main scanning direction is increased. The effective beam width becomes longer.

[0020]

[Brief description of drawings]

FIG. 1 is a block diagram of a digital print processor equipped with a film scanner adopting an illumination optical system according to the present invention.

[Figure 2] Block diagram of film scanner

FIG. 3 is a perspective view showing an example of an illumination optical system which is a starting technology of the present invention .

4 is an illustration of the illumination optical system according to FIG.

FIG. 5 is an explanatory diagram showing an illumination optical system according to the present invention .

Continuation of the front page (56) Reference JP-A-9-18655 (JP, A) JP-A-4-100476 (JP, A) JP-A-11-69093 (JP, A) Actual development Sho-53-10235 (JP , U) Actual development 60-55158 (JP, U) Actual development 61-145928 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 1/04 101

Claims (3)

(57) [Claims] And 1. A line-like that extends in a first direction the light source, a film scanner for illumination optical system including a focusing means for irradiating the photographic film while the light beam converged from the light source, The condensing unit condenses the light of the light beam from the light source in a second direction orthogonal to the first direction and the light in both end regions of the light beam of the light source in the first direction. It also consists of a second condensing unit that condenses
In, the first condensing part is formed as a cylindrical lens.
And the second condensing part of this cylindrical lens is
Arranged around both ends separately from the cylindrical lens
An illumination optical system for a film scanner, which is formed as two condensed lenses . 2. Each of the condenser lenses is the cylindrical
The light beam incident from the lens side is converged in the first direction.
A contract characterized by being configured as a convex lens
The illumination optical system for a film scanner according to claim 1.
Mu. 3. The arrangement of each condenser lens is different from that of the light source.
Adjustable according to the optical characteristics of the cylindrical lens
The file according to claim 1 or 2, characterized in that
Illumination optical system for LUM scanner.