JP2000266690A - Method and apparatus for detecting position of flaw or foreign matter, and image reading device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make detectable the position of a flaw and foreign matter on a transmissible manuscript. SOLUTION: A light shading plate 70 moving in a sub-scanning direction and capable of being arranged on a light diffusing plate 26B and slightly shorten than the light diffusion plate 26B in its length dimension in the sub-scanning direction is provided on an image reading device and, at a time of irregular search scanning, the shading plate 7 is moved on the light diffusing plate 26B to cut off the illumination light ejected from the light diffusing plate 26B to be incident on a lens iris 59. By this constitution, only light obliquely incident from both end parts in the sub-scanning direction of the light diffusing plate 26B is changed over to dark field illumination allowed to irradiate the reading position of a photographic film F. When there is a flaw E or foreign matter D on the photographic film F supported at the reading position, the illumination lights emitted from both end parts of the light diffusion plate 26B are refracted or scattered by the damage E or foreign matter D to be incident on the lens iris 59 to be detected by a line CCD(charge coupled device). By this constitution, the position of a flaw E or foreign matter D is obtained as a brightly reflected image.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a position of a flaw or foreign matter, a device for detecting a position of a flaw or foreign substance, and an image reading apparatus. The present invention relates to a foreign matter position detecting method, a scratch or foreign matter position detecting device, and an image reading device.

[0002]

2. Description of the Related Art In recent years, a film image recorded on a photographic film is transferred to a line CCD (charge coupled device) while the photographic film is conveyed in a sub-scanning direction at a constant reading speed.
e) An image reading device that reads with a scanner, performs various corrections and the like on the image data obtained by the reading, and then records an image on a recording material such as photographic paper, displays an image on a display, and the like. Has been put to practical use. Such an image reading apparatus reads an image recorded on a photographic film and records an image on a recording material such as a photographic paper, as compared with a conventional image reading apparatus that records a film image on a photographic paper by surface exposure. There is an advantage that automation of the operation up to is facilitated.

In the above-described image reading apparatus, generally, light emitted from a light source is diffused by a light diffusion plate, and the diffused light is radiated on a photographic film (hereinafter, referred to as a "transparent original"). As a result, in the image formed by the image forming optical system, fine scratches and foreign matter attached to the transparent original document become inconspicuous, and it is possible to suppress deterioration in image quality due to the scratches and foreign matter. Also, at this time, the effect of suppressing the deterioration of the image quality due to scratches or foreign matter improves as the diffusion rate of the light diffusion plate increases. In addition, foreign substances adhering to the transparent original include dust,
There are dust, dirt, fingerprints, etc.

[0004]

However, when the diffusivity increases, the loss of light amount increases, and the light amount of light emitted from the light source to the transparent original decreases. In addition, the amount of light emitted by the light source is restricted because the amount of heat generated from the light source is limited and reduction in power consumption by the light source is required. For this reason, the magnitude of the diffusion rate of the light diffusion plate is also restricted, and it is not possible to sufficiently suppress image quality deterioration due to scratches or foreign matter on the transparent original during image reading by the CCD scanner.

As described above, in the uniform processing for a transparent original at the time of reading an image, there is a limit to the effect of suppressing the deterioration of image quality. It is required to perform processing for removing the influence of the scratch or foreign matter on the read image at the position.

[0006] For example, in the field of image processing, a method of obtaining high-quality images by correcting data of defective pixels (including lines and areas) (for example, interpolation of defective pixel data from peripheral pixel data, etc.). ) Has been devised. In the above-described image reading apparatus, a defective pixel due to a scratch or foreign matter in the image data read by the CCD scanner is specified, and image processing for correcting the data of the defective pixel is performed. The effects of scratches and foreign matter can be eliminated.

Further, since the scratches and foreign matters attached to the transparent original are minute, even if the output of the light source is increased, the heat generation amount and the power consumption of the light source in the entire image reading process will be provided if only the scratches and foreign matters are increased. The effect is small. Therefore, it is possible to increase the amount of light from the light source and irradiate the diffused light only to the scratch or foreign matter portion on the transparent original, thereby suppressing the deterioration of the image quality due to the scratch or foreign matter.

However, in the prior art, there is no means for detecting (specifying) the position of a scratch or foreign matter on a transparent original, and therefore, it has not been possible to perform processing for removing the influence of a scratch or foreign matter from a read image.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a method for detecting the position of a scratch or foreign matter on a transparent original, a device for detecting the position of a scratch or foreign matter, and a device for detecting the position of a scratch or foreign matter It is an object to provide an image reading device.

[0010]

According to one aspect of the present invention, there is provided a method for detecting the position of a scratch or foreign matter on a transparent original, comprising the steps of: The transmission original is irradiated with dark field light to a photoelectric conversion element, and the position of a scratch or a foreign substance on the transmission original is determined based on a result of detection of the transmitted light by the photoelectric conversion element.

According to the first aspect of the present invention, since the light is radiated to the transmissive document so that the photoelectric conversion element becomes dark field light, the light transmitted to the transmissive document (dark field light) is irradiated. Light) is normal (when there is no scratch or foreign matter on the transparent original)
Not detected by the photoelectric conversion element. On the other hand, if the transparent original has scratches or foreign matter (dust, dust, dirt, fingerprints, etc.), the dark field light is refracted or scattered by the scratches or foreign matter,
Since the light is transmitted in a direction different from the normal direction (when there is no scratch or foreign matter on the transparent original), it is detected by the photoelectric conversion element.

Therefore, for example, when transmitted light of a predetermined amount or more is detected by the photoelectric conversion element as described in claim 2, light refracted or scattered by a scratch or foreign matter on the transmitted original is detected. Determining the position of the scratch or foreign matter on the transparent original based on the result of detection of the transmitted light by the photoelectric conversion element, such as recognizing that a scratch or foreign matter is present on the transparent original. Can be.

According to a third aspect of the present invention, there is provided a scratch or foreign matter position detecting device for detecting a position of a scratch or foreign matter attached to a transparent original, wherein the irradiating means for irradiating the transparent original with light; A photoelectric conversion element that detects transmitted light of the document as dark-field light; and a determination unit that determines a position of a scratch or a foreign matter on the transmission document based on a detection result of light by the photoelectric conversion element. It is characterized by.

According to the third aspect of the present invention, the illuminating means irradiates the transparent original with light, which transmits through the transparent original and is detected by the photoelectric conversion element as dark field light. That is, since light is applied to the transmission original so that the photoelectric conversion element becomes dark-field light, the photoelectric conversion element is used only when the transmission original has a scratch or foreign matter.
Light refracted or scattered by a wound or foreign matter (dark field light)
Is detected.

Therefore, for example,
As described in claim 4, when the photoelectric conversion element detects transmitted light of a predetermined amount or more, it is determined that a scratch or a foreign substance exists at a position on the transparent original where the dark field light is transmitted. For example, it is possible to determine the position of a scratch or foreign matter on the transparent original based on the detection result of the transmitted light by the photoelectric conversion element, such as recognition.

According to a fifth aspect of the present invention, there is provided an image reading apparatus using the flaw or foreign matter position detecting device according to the third or fourth aspect, wherein the determination means determines the position of the flaw or foreign matter. It is characterized by having a correction means for correcting the read result of the transmission image based on the result.

According to the fifth aspect of the present invention, the result of reading the transparent image (the result of reading the image recorded on the transparent document) is based on the detection result of the position of the scratch or foreign matter on the transparent document by the correction means. Is corrected. That is, the position of a scratch or foreign matter on the transparent document can be detected, and the read image corresponding to the position of the scratch or foreign matter on the transparent document can be subjected to processing for removing the influence of the scratch or foreign matter.

According to a sixth aspect of the present invention, there is provided an image reading apparatus which irradiates light from a irradiating means to a transparent original and reads at least the transmitted image by a photoelectric conversion element. A switching unit for irradiating the transparent original by switching light from the irradiating unit to dark field light with respect to the photoelectric conversion element, and the switching unit. By, when irradiating the transparent original with dark field light from the irradiating means, based on the detection result of the transmitted light by the photoelectric conversion element, determining means for determining the position of a scratch or foreign matter on the transparent original, It is characterized by having.

According to the invention described in claim 6, the scratch or foreign matter position detecting device has the switching means and the determining means. The switching unit switches the light from the irradiating unit to the photoelectric conversion element so as to be dark-field light, and irradiates the transparent original. At this time, in the photoelectric conversion element, the aforementioned claim 3
As in the invention described in (1), light (dark field light) refracted or scattered by the scratch or foreign matter is detected only when the transparent original has a scratch or foreign matter. The determination means can determine the position of a scratch or foreign matter on the transparent original based on the detection result of the transmitted light by the photoelectric conversion element at this time.

Further, since the switching means can switch to dark-field light, the irradiation means used for reading the image of the transparent original and the irradiation means used for detecting a scratch or foreign matter can be shared. it can. In addition, the photoelectric conversion element detects a transmitted image from a transparent original and dark field light refracted by a scratch or foreign matter on the transparent original. That is, the photoelectric conversion element used for reading the image of the transmission original and the photoelectric conversion element used for detecting a scratch or a foreign substance can be shared.

According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the switching means is disposed between the irradiating means and the transmissive original, and is provided with a bright field light for the photoelectric conversion element. Light guiding means for guiding light including dark-field light to the photoelectric conversion element to the vicinity of the transmissive document, and a light-shielding position provided between the light guiding means and the transmissive document to block the bright-field light; Light-shielding means capable of selectively taking the retracted position, wherein the determining means determines whether or not the light is transmitted over the transparent original based on a result of detection of transmitted light by the photoelectric conversion element when the light-shielding means is at the light-shielding position. The position of a flaw or foreign matter is determined.

According to the seventh aspect of the present invention, the switching means includes an optical waveguide means and a light shielding means. The light guide means guides the bright field light to the photoelectric conversion element to the vicinity of the transmissive document and irradiates the transmissive document. In addition, the optical waveguide means guides the dark field light to the photoelectric conversion element together with the bright field light to the vicinity of the transparent original and irradiates the transparent original.

The light-shielding means is provided between the optical waveguide means and the transmissive document, and can selectively take a light-shielding position for shielding the bright-field light and a retreat position. That is, it is possible to switch between irradiating the transparent original with bright-field light (so-called bright-field illumination) and irradiating only dark-field light (so-called dark-field illumination) depending on the position of the light-shielding means.

More specifically, by setting the light-shielding means at the retracted position, bright-field illumination can be achieved, and by detecting the bright-field light transmitted through the transmissive original with a photoelectric conversion element,
An image recorded on a transparent original can be read. In addition, by setting the light shielding unit to the light shielding position, dark field illumination can be achieved. The discriminating unit detects scratches or foreign matter on the transmission original based on the detection result of the transmitted light by the photoelectric conversion element at this time. The position can be determined.

The invention according to claim 8 is used in an image reading apparatus for irradiating light to a transparent original from an irradiating means and reading at least the transmitted image by a photoelectric conversion element, wherein a scratch or a foreign matter attached to the transparent original is provided. And a pre-irradiation means for irradiating the transparent original with light so that dark-field light is emitted to the photoelectric conversion element; and A determination unit configured to determine a position of a scratch or a foreign matter on the transparent document based on a detection result of the transmitted light by the photoelectric conversion element when the document is irradiated with light.

According to the eighth aspect of the present invention, the scratch or foreign matter position detecting device is provided with a preliminary irradiating means separately from the irradiating means for irradiating light for reading the image of the transparent original.

This preliminary irradiating means irradiates light to the transmission original so that the photoelectric conversion element becomes dark field light. That is, the preliminary irradiation unit irradiates the transparent original with dark field light for detecting the position of a scratch or a foreign substance on the transparent original.

In the photoelectric conversion element, similarly to the above-described third aspect, only when the transparent original has a scratch or foreign matter, the light refracted or scattered by the scratch or foreign matter (dark field light). Is detected, it is possible to determine the position of a scratch or a foreign matter on the transparent original based on the detection result of the transmitted light by the photoelectric conversion element. Further, similarly to the above-described invention, the photoelectric conversion element used for reading the image of the transparent original and the photoelectric conversion element used for detecting the scratch or the foreign matter can be shared. .

According to a ninth aspect of the present invention, there is provided an image reading apparatus which irradiates light from an irradiating unit and reads a transmitted image thereof by a photoelectric conversion element, and detects a position of a scratch or a foreign substance on the transparent original. A first photoelectric conversion element, wherein the photoelectric conversion element receives light emitted from the irradiating means on the transmitted image as bright-field light; and A second photoelectric conversion element that receives light irradiated on the image as dark-field light, and based on a detection result of transmitted light by the second photoelectric conversion element, It is characterized by having determining means for determining the position.

According to the ninth aspect, the photoelectric conversion element includes the first photoelectric conversion element and the second photoelectric conversion element. The first photoelectric conversion element irradiates the transmissive original with the irradiating means and receives light transmitted through the transmissive original as bright-field light. Therefore, the first photoelectric conversion element can read an image recorded on a transparent original.

On the other hand, the second photoelectric conversion element irradiates the transmissive original by the irradiating means and receives light transmitted through the transmissive original as dark field light. That is, in the second photoelectric conversion element, of the light radiated to the transmissive document by the irradiating means,
The transmitted light is refracted by a flaw or foreign matter on the transmission original, and receives the transmitted light.

The scratch or foreign matter position detecting means is provided with a discriminating means. The determining means may determine, for example, the second signal based on the detection result of the transmitted light by the second photoelectric conversion element.
When the transmitted light of a predetermined amount or more is detected by the photoelectric conversion element, the position of the scratch or foreign matter on the transparent original is determined by recognizing the presence of a scratch or foreign matter on the transparent original.

At this time, as described above, the first photoelectric conversion element used for reading an image recorded on the transparent original and the second photoelectric conversion element used for determining the position of a scratch or foreign matter are provided. Since it is provided separately, the position of a scratch or a foreign substance on the transparent document can be determined at the same time as reading the image recorded on the transparent document.

According to a tenth aspect of the present invention, in the first aspect of the present invention, the photoelectric conversion elements are arranged in a line, and the transparent original is arranged in the line. Recording an image while moving the photoelectric conversion element in a direction orthogonal to the photoelectric conversion element.

According to the tenth aspect of the present invention, the photoelectric conversion elements used for detecting scratches and foreign matter on the transparent original are arranged in a line. The photoelectric conversion element detects light transmitted through the transparent original by being refracted by a scratch or a foreign substance while moving the transparent original at a constant speed in a direction orthogonal to the photoelectric conversion elements arranged in a line.
Therefore, the scratch or foreign matter position detecting device can acquire an image indicating the position of the scratch or foreign matter on the image transmitting document based on the amount of light detected by the photoelectric conversion element.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) Next, an example of an embodiment according to the present invention will be described in detail with reference to the drawings. In this embodiment, the present invention is applied to an image reading apparatus that reads a film image recorded on a photographic film. The schematic configuration of the image reading apparatus 10 is shown in FIGS.

The scanner section 12 is for reading a film image recorded on the photographic film F,
For example, film images of 135 size photographic film, 110 size photographic film, photographic film having a transparent magnetic layer formed thereon (240 size photographic film: so-called APS film), 120 size and 220 size (Broni size) photographic film To be read.

The scanner section 12 reads a film image to be read and outputs image data to the image processing section 14. When the image data output from the scanner unit 12 is input, the image processing unit 14 performs image processing such as various corrections on the image data to obtain image data for recording, and then, for example, a laser printer unit (not shown). ).

As shown in FIG. 2, in the image reading apparatus 10, a light source section 24 is disposed below the scanner section 12 with the work table 11 interposed therebetween. In the image reading apparatus 10, a mirror box 26 and a film carrier 28 are arranged between the scanner section 12 and the light source section 24 along the optical axis L1. 11 is detachably mounted.

The light source unit 24 includes a lamp 30 such as a halogen lamp or a metal halide lamp, and a reflector 32.
And housed in a metal casing 34.
The reflector 32 has a light reflecting surface formed of a concave curved surface, and surrounds the lamp 30 by the light reflecting surface. Part of the light emitted from the lamp 30 is emitted as direct light in a direction along the optical axis L1, and another part is reflected by the reflector 32.
And emitted as reflected light in a direction along the optical axis L1.

The turret 40 is formed in a disk shape as shown in FIG. 3, and is supported by a rotation axis (not shown) parallel to the optical axis L1. The turret 40
A negative film balance filter 42 and a reversal film balance filter 44 for adjusting the color component of the light applied to the photographic film F according to the type of the film (negative film / reversal film) are fitted. The position of the turret 40 in the rotation direction is adjusted so that one of the balance filters 42 and 44 (the balance filter 42 in FIGS. 3 and 4) is supported on the optical axis L1.

As shown in FIG. 4, the mirror box 26 is formed in a cylindrical shape whose both ends in the axial direction, that is, the lower end and the upper end are closed by light diffusion plates 26A and 26B, respectively. As shown in the figure, the width in the sub-scanning direction (arrow S direction) along the transport direction of the photographic film F decreases from the lower end to the upper end, and the width in the main scanning direction (arrow M direction) orthogonal to the sub-scanning direction is reduced. The shape is such that the width becomes wider. The inner peripheral surface of the mirror box 26
The light reflection surface 26C has a high light reflectance.

Here, the mirror box 26 is formed by coating the inner peripheral surface of the mirror box 26 with a material having a high light reflectivity, or by forming the inner peripheral surface of the mirror box 26 with a material having a high light reflectivity. , A light reflection surface 26C. The light diffusion plates 26A and 26B are made of, for example, a milky white plate, an opal glass, an LSD (light shaving diffuser), or the like. Each of the light diffusion plates 26A and 26B is orthogonal to the optical axis L1 and passes through the optical center. That is, they are arranged so that the optical center axis coincides with the optical axis L1.

The mirror box 26 converts the light incident on the light diffusing plate 26A from the light source 24 through the balance filter 42 from the light diffusing plate 26B into a slit-like light whose longitudinal direction is the width direction (main scanning direction) of the photographic film F. The photographic film F supported on the reading position R is irradiated as (illumination light). At this time, the illumination light emitted from the mirror box 26 is diffused by the light diffusing plates 26A and 26B to be diffused light that spreads in an irregular direction, and is incident on the photographic film F per unit area. The amount of light is made uniform. The illumination light becomes a light beam having the optical axis L1 as a symmetric axis since the light diffusion plate 26B has the optical axis L1 as the optical central axis.

The film carrier 28 is provided with a slit-like opening (not shown) that is long in the main scanning direction at positions corresponding to the optical axis L1 on the upper surface and the lower surface. Accordingly, the light emitted from the mirror box 26 is applied to the photographic film F through an opening provided on the lower surface of the film carrier 28, and the light transmitted through the photographic film F is transmitted to the opening provided on the upper surface of the film carrier 28. And is formed into a slit shape to reach the scanner unit 12.

In the film carrier 28, there are provided a pair of rollers (not shown) for nipping and transporting the photographic film F to positions upstream and downstream with respect to the reading position R, respectively. The photographic film F is transported in the film carrier 28 at a predetermined speed by the roller pair. The photographic film F in the film carrier 28 is
As shown in FIG. 3, the guide plate or the like (not shown) curves upward in a convex shape, and the top is supported so as to coincide with the reading position R.

As shown in FIG. 5, a light shielding plate 70 is provided above the light diffusing plate 26B. The light shielding plate 70 is made of an opaque synthetic resin, and can completely block light. The light-shielding plate 70 has a longitudinal direction in the main scanning direction, and is formed longer than the length of the light diffusion plate 26B in the main scanning direction. Sub-scanning direction (short side) of light shielding plate 70
Is slightly shorter than the length of the light diffusion plate 26B in the sub-scanning direction.

A pair of guide shafts 72 are arranged at both ends of the light shielding plate 70 in the main scanning direction. The light shielding plate 70
Guided by the guide shaft 72, the light-shielding plate 70 can be moved in the sub-scanning direction while the center line of the light-diffusing plate 26B in the main scanning direction coincides with the center line of the light diffusion plate 26B.

The light shielding plate 70 is arranged at the downstream side in the transport direction of the photographic film F as shown in FIG. 5A when reading images (during prescanning or fine scanning described later). That is, all the light emitted from the light diffusion plate 26B is applied to the photographic film F.

When a scratch or a foreign matter on the photographic film F is detected (at the time of an irregular search scan described later),
It moves in the sub-scanning direction (see the arrow S in FIG. 5A).
As shown in (B), they are arranged on the light diffusion plate 26B so that the center lines in the sub-scanning direction coincide with each other. Accordingly, light emitted from the central portion of the light diffusion plate 26B is blocked by the light shielding plate 70. At this time, since the length dimension of the light-shielding plate 70 in the sub-scanning direction (short side) is shorter than the length of the light diffusing plate 26B in the sub-scanning direction, as described above, Light is emitted from both end portions 26B1 and 26B2 without being blocked by the light shielding plate 70.

The scanner section 12 has a casing 48 as shown in FIG. In the casing 48,
A mounting table 52 on which a line CCD 50 is mounted is provided on the upper surface, and a plurality of parallel support rails 54 extend downward from the lower surface of the mounting table 52. A lens unit 56 as an imaging optical system is disposed on the support rail 54, and the lens unit 56 is supported by the support rail 54 so as to be movable in the axial direction.
Therefore, by moving the lens unit 56 in the axial direction, the magnification of the film image formed on the line CCD 50 can be changed.

On the work surface 11A of the work table 11, a support frame 58 is provided upright as shown in FIG. The support frame 58 is engaged with an end of the mounting table 52, and supports the mounting table 52 so as to be movable in the axial direction. This makes it possible to secure a conjugate length during zooming and during autofocus. The lens unit 56 includes a plurality of lenses, and a lens diaphragm 59 is provided between the lenses. The lens diaphragm 59 changes the area of an opening centered on the optical axis L1 to adjust the amount of light incident on the line CCD 50.

The line CCD 50 is provided with a three-line sensing unit. Each sensing unit configured as a light receiving unit includes a large number of photoelectric conversion elements and a shutter mechanism including a large number of CCD cells and photodiodes arranged in a line in the main scanning direction. One of R, G, and B color separation filters is attached to the light incident side (a so-called three-line color CCD). Also, there are many CCDs near each sensing part.
A transfer unit including a cell is provided for each sensing unit.

The line CCD 50 converts the electric charge stored in the CCD cell into a line signal corresponding to the image density of the photographic film F along the main scanning line at every cycle corresponding to the transport speed of the photographic film F. (Not shown). The image processing unit 14 converts a line signal from the line CCD 50 into a digital signal, and stores the digital signal in a memory to generate an image signal.

On the light incident side of the line CCD 50, a CCD shutter 60 is provided as shown in FIG.
The CCD shutter 60 has an ND filter (not shown).
Is fitted. The CCD shutter 60 is rotatably supported. The CCD shutter 60 supports a light-shielding portion, in which the ND filter is not fitted, on the optical axis L1 to block light incident on the line CCD 50, and is retracted from the optical axis L1. One of the fully opened state in which the incident light to the line CCD 50 is not blocked, and the ND filter supported on the optical axis L1 to reduce the incident light to the line CCD 50 by the ND filter for linearity correction. Switch to

The image reading apparatus 10 configured as described above
Then, after performing a pre-scan for preliminarily reading the photographic film F by the scanner unit 12, a fine scan for obtaining image data for reproduction is performed. After the end of the fine scan, an irregular search scan for detecting the position of a scratch or foreign matter on the photographic film F is performed.

The pre-scanning is performed with the reading conditions set by the light source aperture 38, the lens aperture 59, the CCD shutter 60, etc. fixed, and the transport speed of the photographic film F being high. In addition, as shown in FIG.
It is arranged outside the light diffusion plate 26B in the transport direction of the photographic film F. Thus, scanning is performed by so-called bright-field illumination in which illumination light emitted from the light diffusion plate 26B enters the lens stop 59.

The image reading device 10 determines the image density, color balance, etc. of the film image of the photographic film F based on the image data obtained by the pre-scan, and based on the determination result, performs a fine scan for the film image. Is set.

The fine scan is carried out by transporting the photographic film F in the direction opposite to the prescan, and at a lower speed than the prescan.
At this time, fine scan is performed under bright-field illumination similarly to prescan without moving the light shielding plate 70 from the arrangement position at the time of prescan. The image processing unit generates an image signal for reproduction from a line signal corresponding to the image density of the photographic film F obtained by the fine scan.

In the irregular search scan, the light shielding plate 7 is used.
0 is moved onto the light diffusion plate 26B (see the arrow A in FIG. 6). Thus, the illumination light emitted from the light diffusion plate 26B and directly incident on the lens diaphragm 59 is blocked by the light shielding plate 70, and both ends 26B1, 26 of the light diffusion plate 26B.
Illumination light is emitted only from B2. Therefore, only the illumination light inclined in the sub-scanning direction with respect to the optical axis L1 (that is, from the oblique direction) is irradiated to the reading position R of the photographic film F. It does not enter (so-called dark field illumination).

The scanning under the dark field illumination is performed, and the line signal obtained by the line CCD 50 is transferred to the image processing converter in the same manner as in the fine scan. The image processor 14 converts the line signal from the line CCD 50 into a digital signal to generate image data.

Here, the image data obtained by the irregular search scan will be described. FIG. 7 is a conceptual diagram of a path followed by illumination light during an irregular search scan. In FIG. 7, the path of the illumination light emitted from one end 26B1 of the light diffusion plate 26B is indicated by a dashed-dotted arrow I, and the path of the illumination light emitted from the other end 26B2 is omitted.

In the irregular search scan, usually (when the photographic film F has no scratches or foreign matter),
As shown in FIG. 7A, the light emitted from the end of the light diffusion plate 26B passes through the photographic film F supported at the reading position R without changing the traveling direction. Therefore, no illumination light is incident on the lens stop 59.

When the photographic film F supported at the reading position R has a flaw E, as shown in FIG. 7B, the illumination light emitted from one end 26B1 of the light diffusing plate 26B is
The light is refracted by the flaw E and enters the lens stop 59. The illumination light incident on the lens diaphragm 59 is detected by the line CCD 50.

When the foreign matter D adheres to the photographic film F supported at the reading position R, as shown in FIG. 7C, the illumination emitted from one end 26B1 of the light diffusion plate 26B. Light is scattered by the foreign matter D. this house,
Illumination light scattered in the direction of the lens stop 59 is the line CC
D50 is detected.

That is, in the irregular search scan, the line CCD 50 detects the illuminating light only from the portion of the photographic film F where the scratch or foreign matter is attached, so that the position of the scratch or foreign material is brightly reflected (the pixel value is large). , And other parts are obtained as dark image data (small pixel values).

The image processing unit 14 generates image data indicating the position of a scratch or foreign matter on the photographic film F from the image data. Further, the image processing unit 14 compares the image data indicating the position of the flaw or foreign matter with the image data obtained by the fine scan, and according to a predetermined algorithm, the influence of the flaw or foreign matter is not noticeable.
The image data obtained by the fine scan is corrected.

The processing performed by the image processing section 14 is not particularly limited here. For example, the pixel value of a pixel having a pixel value equal to or greater than a predetermined value (that is, a pixel corresponding to a portion having a scratch E or foreign matter D) is replaced with 1, and a pixel having a pixel value equal to or less than a predetermined value (that is, having a scratch E or foreign matter D is attached). The pixel value of the pixel corresponding to the non-existent portion) is replaced with 0 to generate binary image data indicating the position of a flaw or foreign matter. In the obtained binary image data, the value of the pixel of the image data obtained by the fine scan corresponding to the pixel having the pixel value of 1 (that is, the pixel at the position of the scratch or the foreign matter) is defined as the peripheral pixel of the pixel. The method may be a method that makes the influence of a scratch or a foreign substance inconspicuous by replacing the value obtained by interpolation from the value of, or another method.

Next, the operation of the image reading apparatus 10 according to the present embodiment configured as described above will be described.

When the photographic film F is set, in the image reading apparatus 10, the light source aperture 38, the lens aperture 59, the CC
The reading conditions of the D shutter 60 and the like are set to predetermined values for pre-scanning. When the setting of the reading conditions is completed, the photographic film F is transported at a high speed, and the prescan is started.

The illuminating light emitted from the light diffusion plate 26 B of the mirror box 26 is applied to the photographic film F supported at the reading position R. At this time, the illumination light emitted from the mirror box 26 becomes a light beam with the optical axis L1 as the axis of symmetry. As a result, light having an amount of light corresponding to the image density passes through the image recording area of the photographic film F supported at the reading position R, and the illumination light carrying the film image also forms a light beam having the optical axis L1 as a symmetric axis. As a result, the light enters the lens diaphragm 59 of the lens unit 56 and is detected by the line CCD 50. The line signal based on the image density obtained by the line CCD 50 is transferred to the image processing unit 14 to generate image data (low resolution).

The image processing section 14 determines the image density, color balance, etc. of the film image of the photographic film F based on the image data (low resolution) obtained by the prescan. Further, a reading condition for a fine scan for a film image is obtained based on the determination result.

When the prescan of all the film images of the photographic film F is completed, the reading conditions are set to the values for the fine scan obtained by the prescan. When the setting of the reading conditions is completed, the photographic film F is transported at a low speed in a direction opposite to the transport direction of the prescan, and fine scan is started. The photographic film F is irradiated with illumination light in the same manner as in the pre-scan, and light having a light amount corresponding to the image density is detected by the line CCD 50.

The line signal based on the image density obtained by the line CCD 50 is transferred to the image processing section 14 to generate image data (high resolution). The generated image data is stored in the memory.

When the fine scan of all the film images of the photographic film F is completed, the light shielding plate 70 is
6B. Thereby, the illumination light emitted from the light diffusion plate 26B and incident on the lens stop 59 is blocked,
Switching is performed to dark field illumination in which some light leaks from both ends of the light diffusion plate 26B. As a result, the photographic film F is irradiated with illumination light from an oblique direction (tilted with respect to the optical axis L1).

When the light shielding plate 70 is set on the light diffusion plate 26B and switched to dark field illumination, the transport direction of the photographic film F is reversed (the transport direction is the same as the pre-scan direction) and transported at a low speed. The irregular search scan starts.

In the irregular scan, if the photographic film F supported at the reading position R has a flaw E or foreign matter D, the illumination light emitted from both ends of the light diffusing plate 26B is applied to the flaw E or foreign matter D. The light enters the line CCD 50 after being refracted or scattered. When the irregular search scan is completed,
Image data in which only the portion of the photographic film F where the scratch E or the foreign matter D is attached is brightly obtained is obtained.

The image processing section 14 generates image data indicating the position of a scratch or foreign matter on the photographic film F from the image data. The image data obtained by the fine scan is compared with the image data indicating the position of the scratch or the foreign matter and the image data obtained by the fine scan, and according to a predetermined algorithm, the influence of the scratch or the foreign matter is not conspicuous. Is corrected.

As described above, in the first embodiment, the light shielding plate 70 is moved over the light diffusing plate 26B to switch from bright field illumination to dark field illumination, and the irregular search scan is performed under dark field illumination. By doing so, the position of a scratch or foreign matter on the photographic film F can be detected.

(Second Embodiment) In the first embodiment, the light shielding plate 70 is used to switch from bright field illumination to dark field illumination. However, the present invention is not limited to this. For example, as shown in FIG. 8, a sub-mirror box and a light source unit may be newly provided for dark field illumination. In FIG. 8, the same members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

As shown in FIG. 8, the mirror box 2
6, a pair of sub-mirror boxes 80 are arranged outside in the sub-scanning direction. The sub-mirror boxes 80 are arranged adjacent to both ends of the mirror box 26 in the sub-scanning direction. These pair of sub mirror boxes 8
0 has the same structure as the mirror box 26,
The lower end and the upper end are formed in a cylindrical shape closed by light diffusion plates 80A and 80B, respectively, and the inner peripheral surface is formed as a light reflecting surface 80.
C.

A light source section 82 having the same configuration as the light source section 24 is disposed below the light diffusion plate 80A. The sub-mirror box 80 converts the light incident on the light diffusion plate 80A from the light source unit 82 from the light diffusion plate 80B into a rectangular light having a longitudinal direction in the width direction (main scanning direction) of the photographic film F (illumination for dark field illumination). The photographic film F supported on the reading position R is irradiated as light).

The sub-mirror box 80 is arranged so that its optical axis L2 is inclined with respect to the optical axis L1 in the sub-scanning direction. It does not enter the light source 59.

Next, the operation of the second embodiment will be described.

When the photographic film F is set, in the image reading apparatus 10, the light source 24 is turned on, and the light source 82 is turned off.
F, a pre-scan is performed as in the first embodiment, and then a fine scan is performed.

At this time, the photographic film F is
As shown in (A), illumination light is not emitted from the light diffusion plate 80B, and illumination light is emitted only from the light diffusion plate 26B. That is, pre-scan and fine scan are
The illumination light emitted from the light diffusing plate 26B is
Is performed under bright field illumination incident on

When the fine scan is completed, on the contrary,
The light source unit 24 is turned off and the light source unit 82 is turned on, and an irregular search scan is performed as in the first embodiment.

At this time, the photographic film F is
As shown in (B), illumination light is not emitted from the light diffusion plate 26B, and illumination light is emitted only from the light diffusion plate 80B.

The illumination light emitted from the light diffusion plate 80B is
Normally (when there is no scratch or foreign matter on the photographic film F), the illuminating light is irradiated on the photographic film F while being inclined with respect to the optical axis L1 and transmitted as it is, so that no illumination light enters the lens diaphragm 59 (FIG. B)).

If the photographic film F has a flaw or foreign matter, the illumination light emitted from the light diffusion plate 80B is refracted by the flaw E or scattered by the foreign matter. The refracted or scattered illumination light is incident on a lens stop 59, and the line CCD 5
0 (see FIG. 9C). As a result, similarly to the first embodiment, image data indicating the position of a scratch or foreign matter on the photographic film F can be obtained.

As described above, in the second embodiment, the sub-mirror box 80 for dark field illumination that irradiates the photographic film F with illumination light while tilting in the sub-scanning direction with respect to the optical axis L1.
And a light source unit 82, and by performing an irregular search scan under dark-field illumination, the position of a scratch or foreign matter on the photographic film F can be detected.

In the second embodiment, the light source 82 is turned off during pre-scanning and fine scanning so that illumination light is not emitted from the sub-mirror box 80. However, the present invention is not limited to this. The illumination light from the mirror box 26 and the illumination light from the sub-mirror box 80 may be applied to the photographic film F together with the illumination light from the mirror box 26 during the pre-scan and the fine scan. In this case, the photographic film F is illuminated with the illumination light diffused better without changing the diffusivity of the light diffusing plates 26A and 26B. 56 makes it possible to make inconspicuous image defects at portions corresponding to scratches in the film image formed. That is, it is possible to suppress a decrease in image quality of an image reproduced based on the image data read by the line CCD 50.

The mechanism (light shield plate 70, sub-mirror box 80, etc.) for realizing dark field illumination shown in the first and second embodiments is shown as an example, and the present invention is not limited to this. Not something. Any structure may be used as long as the mechanism detects the position of a scratch or foreign matter on the photographic film F by dark field illumination.

For example, as shown in FIG. 10, a lens unit 100 and a line CCD 102 for detecting the position of a scratch or foreign matter on the photographic film F may be newly provided. In this case, the lens unit 56 and the line C
The CD 50 receives the light (dashed-dotted line I) emitted from the light diffusion plate 26B and transmitted through the normal (no scratch or foreign matter) photographic film F, and reads the film image (FIG. 10).
(A)).

The lens unit 100 and the line CC
D102 receives the light dashed line I) deflected by the scratch or foreign matter attached to the photographic film F, and detects the position of the scratch or foreign matter on the photographic film F (see FIG. 10B). In this case, at the time of reading the film image of the photographic film F, it is also possible to simultaneously detect the position of a scratch or foreign matter on the photographic film F.

A mechanism for detecting the position of a scratch or foreign matter (light source, mirror box, lens unit, line CCD, etc.)
May be provided in the apparatus completely independently of the mechanism for reading the film image of the photographic film F.

Although the illumination light of the dark field illumination is guided to the vicinity of the photographic film F by the mirror box 26 or the sub mirror box 80, the present invention is not limited to this. For example, the illumination light of dark field illumination may be guided to the vicinity of the photographic film F using an optical fiber.

Further, in the image reading apparatus for reading the film image of the photographic film F, the case where the position of a scratch or a foreign matter on the photographic film F is detected has been described as an example, but the present invention is naturally not limited to this. Not something. As long as light can be transmitted, the present invention can be applied to any transparent original other than photographic film in order to detect the position of a scratch or foreign matter on the transparent original.

[0099]

As described above, the present invention has an excellent effect that the position of a scratch or foreign matter on a transparent original can be detected.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an external appearance of an entire image reading apparatus according to the present embodiment.

FIG. 2 is a schematic configuration diagram illustrating an internal configuration of the entire image reading apparatus according to the embodiment;

FIG. 3 is a schematic configuration diagram of an optical system of the image reading apparatus according to the embodiment.

FIG. 4 is a cross-sectional view showing an optical system component and a photographic film of the image reading apparatus according to the first embodiment.

FIGS. 5A and 5B are conceptual diagrams showing switching from bright-field illumination to dark-field illumination in the first embodiment, where FIG. 5A shows the position of a light-shielding plate during bright-field illumination, and FIG. The position of the light shielding plate at the time of illumination is shown.

FIG. 6 is a conceptual diagram showing an optical path of illumination light under bright field illumination during image reading (pre-scan and fine scan) according to the first embodiment.

FIG. 7 is a conceptual diagram showing an optical path of illumination light under dark-field illumination when a flaw and a foreign substance are detected (at the time of an irregular search scan) according to the first embodiment. (B) shows the optical path of the illumination light when there is a flaw in the photographic film, and (C) shows the optical path of the illumination light when a foreign substance is attached to the photographic film.

FIG. 8 is a cross-sectional view illustrating optical system components and a photographic film of an image reading apparatus according to a second embodiment.

FIGS. 9A and 9B are conceptual diagrams illustrating an optical path of illumination light according to the second embodiment, in which FIG. 9A illustrates an optical path of illumination light under bright-field illumination (during image reading), and FIG. The light path of the illumination light when there is no flaw or foreign matter in the photographic film under the visual field illumination (at the time of detection of the flaw or foreign matter), and (C) shows the optical path of the illumination light when the photographic film has a flaw.

FIG. 10 is a diagram illustrating a schematic configuration of an optical system of an image reading device and an optical path of illumination light according to another embodiment;
(A) shows the optical path of the illumination light when the photographic film has no scratches or foreign matter, and (B) shows the optical path of the illumination light when the photographic film has a scratch.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Image reading apparatus 12 Scanner part 14 Image processing part (discrimination means, correction means) 24 Light source part (irradiation means) 26 Mirror box (optical waveguide means) 26A Light diffusion plate 26B Light diffusion plate 50 line CCD (photoelectric conversion element, 1 photoelectric conversion element) 70 light shielding plate (light shielding means) 80 sub-mirror box 80A light diffusion plate 80B light diffusion plate 82 light source section (preliminary irradiation means) 102 line CCD (second photoelectric conversion element) D foreign matter E scratch F photographic film

Claims (10)

[Claims] 1. A method for detecting the position of a scratch or foreign matter on a transparent original, the method comprising: irradiating dark-field light to a photoelectric conversion element to the transparent original; Based on the light detection result,
Determining the position of a scratch or foreign matter on the transparent document. 2. The method according to claim 1, wherein when the photoelectric conversion element detects transmitted light of a predetermined light amount or more, the photoelectric conversion element recognizes that a scratch or a foreign substance exists on the transparent original. The method for detecting the position of a scratch or foreign matter described in the above. 3. A flaw or foreign matter position detecting device for detecting a position of a flaw or foreign matter attached to a transmissive document, comprising: an irradiating means for irradiating the transmissive document with light; Based on a photoelectric conversion element that detects as field light, based on a detection result of transmitted light by the photoelectric conversion element,
Determining means for determining the position of a scratch or foreign matter on the transparent document. 4. When the discriminating means detects a transmitted light of a predetermined amount or more by the photoelectric conversion element, a scratch or a foreign substance exists at a position where the dark field light is transmitted on the transmissive document. The scratch or foreign matter position detecting device according to claim 3, wherein the position is detected. 5. An image reading apparatus using the scratch or foreign matter position detecting device according to claim 3 or 4, wherein the transparent original is determined based on a result of the determination of the position of the scratch or foreign matter by the determining means. An image reading apparatus, comprising: a correction unit configured to correct a reading result of the image reading apparatus. 6. An image reading apparatus which irradiates light from an irradiating means to a transparent original and reads at least the transmitted image by a photoelectric conversion element, and detects a position of a scratch or a foreign substance on the transparent original. A foreign matter position detecting device, wherein the light from the irradiating means is switched to the photoelectric conversion element so as to be dark field light, and the switching means irradiates the transparent original; and the irradiating means is provided by the switching means. And determining means for determining the position of a scratch or foreign matter on the transparent document based on a result of detection of the transmitted light by the photoelectric conversion element when irradiating the transparent document with dark field light. Or a foreign matter position detecting device. 7. The transmission document according to claim 1, wherein the switching unit is disposed between the irradiation unit and the transmission original, and transmits light including bright-field light to the photoelectric conversion element and dark-field light to the photoelectric conversion element. Light guiding means for guiding to the vicinity, light shielding means provided between the light guiding means and the transparent document, and a light shielding means for selectively taking a light shielding position for shielding the bright field light and a retracted position, 2. The method according to claim 1, wherein the determining unit determines a position of a scratch or a foreign matter on the transparent original based on a result of detection of transmitted light by the photoelectric conversion element when the light shielding unit is at a light shielding position. 7. The scratch or foreign matter position detecting device according to 6. 8. An image reading apparatus which irradiates light from a irradiating means to a transparent original and reads at least the transmitted image by a photoelectric conversion element, and detects a position of a scratch or a foreign substance on the transparent original. A foreign matter position detecting device, wherein a preliminary irradiating unit that irradiates the transparent original with light so that the photoelectric conversion element becomes dark-field light, irradiating the transparent original with light by the preliminary irradiating unit. And a determination unit configured to determine a position of a scratch or a foreign matter on the transparent document based on a detection result of the transmitted light by the photoelectric conversion element when the detection is performed. 9. A scratch or foreign matter used in an image reading apparatus that irradiates light to a transparent original from an irradiating unit and reads a transmitted image by a photoelectric conversion element, and detects a position of a scratch or foreign matter on the transparent original. A position detecting device, wherein the photoelectric conversion element receives a light emitted from the irradiation unit to the transmission image as bright-field light, and a first photoelectric conversion element that irradiates the transmission image from the irradiation unit. A second photoelectric conversion element that receives the transmitted light as dark-field light, and determines a position of a scratch or a foreign matter on the transmission original based on a detection result of transmitted light by the second photoelectric conversion element. An apparatus for detecting a position of a flaw or foreign matter, comprising a determination unit. 10. The image forming apparatus according to claim 6, wherein the photoelectric conversion elements are arranged in a line, and an image is recorded while moving the transparent original in a direction orthogonal to the photoelectric conversion elements arranged in the line. The wound or foreign matter position detecting device according to any one of claims 9 to 9.