JP2006121598A - Film scanner and shading correction method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To acquire correction data used for appropriate shading correction without deteriorating the performance of a photoelectric conversion unit. <P>SOLUTION: An ND filter G is provided so as to be switched freely to a function position being a part for transmitting rays in a light source unit A and a separation position separated from the function position, and a surface Ga in the ND filter G is finished roughly. As a result, a diffusion surface having diffusion characteristics equal or approximate to those of rays by a photographic film is formed, and the rays from the light source unit A, are received by the CCD line sensor of the photoelectric conversion unit while the ND filter G is set to the function position, thus acquiring light amount distribution in a main scanning direction, and using the correction data for uniformizing the light amount distribution as those used for shading correction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes an imaging optical system that forms an image of a photographic film irradiated with light from a light source unit on a photoelectric conversion surface of a photoelectric conversion unit with an optical lens, and transports the photographic film in the sub-scanning direction. The image data acquisition means that continuously captures the image data of the region along the main scanning direction of the photographic film in cooperation with each other, and the shading correction means that performs shading correction on the image data acquired by the image data acquisition means The present invention relates to a film scanner and a shading correction method for the film scanner.

  There exist what is described in patent document 1 and patent document 2 as a film scanner comprised as mentioned above. That is, in Patent Document 1, the film carrier, the lens unit, and the line CCD are arranged in this order on the side from which the light beam from the light source unit is sent out. A diffuser plate is disposed on the light source side of the film carrier, a glass plate is disposed on the lens side of the film carrier, and a position for conveying the film is disposed between these positions. A correction plate for positive film and a correction plate for negative film are joined to the diffuser plate. When acquiring shading data, the correction plate is arranged on the optical axis and the light quantity distribution is acquired by the line CCD. .

  In Patent Document 2, a film whose frame portion is not exposed is set on a film carrier, a shading scan is started, and shading data is sampled. By performing sampling in this way, it is possible to correct the distribution of the amount of illumination light, the variation in sensitivity of individual elements of the line sensor, and the like.

JP 2000-358142 A (paragraph numbers [0056] to [0078], FIG. 2) JP-A-5-276378 (paragraph numbers [0025] to [0027], FIG. 6)

  As described above, in a film scanner having a structure in which photographic film is conveyed in the sub-scanning direction and image data of a region along the main scanning direction of the photographic film is acquired in the photoelectric conversion unit in cooperation with this conveyance, It is important that the light quantity distribution in the main scanning direction of the light beam irradiated on the light source, and when the light beam from the light source passes through the photographic film, the influence from the photographic film cannot be ignored. As shown in Patent Document 1 and Patent Document 2, shading correction is required.

  The photographic film has a property of diffusing light, and the amount of light in the main scanning direction of the light reaching the photoelectric conversion unit from the photographic film irradiated with the light is affected by scattering in the photographic film, and shading correction is performed. In some cases, the nature of this scattering must be taken into account. Further, when acquiring correction data for realizing shading correction, the light amount of the light source unit is set to the light amount at the time of scanning, so that a large amount of light is directly received by the photoelectric conversion unit. It is conceivable that the photoelectric conversion element is damaged or the performance is deteriorated, and it is desired to improve these disadvantages.

  An object of the present invention is to acquire correction data used for shading correction without degrading the performance of the photoelectric conversion unit.

A feature of the present invention is that it includes an imaging optical system that forms an image of a photographic film irradiated with light rays from a light source unit on a photoelectric conversion surface of a photoelectric conversion unit with an optical lens, and is provided in the sub-scanning direction of the photographic film. An image data acquisition unit that continuously captures image data in a region along the main scanning direction of the photographic film in conjunction with conveyance, and a shading correction unit that performs shading correction on the image data acquired by the image data acquisition unit. In the equipped film scanner,
A diffusing means having a diffusing characteristic equal to or approximating the diffusing characteristic of the light beam by the photographic film; and a dimming means for reducing the amount of the transmitted light beam in the light path for guiding the light beam from the light source unit to the photoelectric conversion unit. It is configured to be switchable between a functional position to be arranged and a separated position to be separated from this optical path,
Correction that generates correction data used for the shading correction based on light amount data along the main scanning direction obtained by the photoelectric conversion unit in a state where the diffusing unit and the dimming unit are set at the functional position at the same time. The data acquisition means is provided.

  With this configuration, by setting the diffusing means and the dimming means at the functional positions, the diffusing means diffuses the light beam from the light source unit with a characteristic equal to the diffusing characteristic of the photographic film, and the dimming means transmits the light beam from the light source unit. The amount of light is reduced, and the correction data can be acquired without reflecting the total light amount from the light source to the photoelectric conversion unit, reflecting the diffusion of light rays in the photographic film without using a photographic film. It is also possible to scan the photographic film by setting the diffusing means and the dimming means at the separated positions. As a result, it was possible to configure a film scanner that acquires appropriate shading data without degrading the performance of the photoelectric conversion unit.

  The present invention includes a film carrier that conveys the photographic film in the sub-scanning direction at an intermediate position between the light source unit and the optical lens, and the diffusing unit and the dimming unit are disposed inside the light source unit. It may be provided so as to be switched between a functional position and a separated position.

  With this configuration, the diffusing unit and the dimming unit are provided inside the light source unit at a position separated from the film carrier. For example, the diffusing unit and the dimming unit are arranged in the vicinity of the position where the photographic film is set. Compared with the above, it is possible to obtain accurate correction data by eliminating the influence of surface irregularities and fine shading caused by imaging the state of these surfaces on the photoelectric conversion surface of the photoelectric conversion unit. Become.

  In the present invention, the light source unit includes a plurality of red light emitting diodes, a plurality of green light emitting diodes, and a plurality of blue light emitting diodes arranged in the main scanning direction, and the light from these light emitting diodes is emitted. The functional position may be set in an optical path that is combined and sent out.

  With this configuration, it is possible to obtain correction data based on white light by disposing the diffusing unit and the dimming unit at the position where the light beams from the three color light emitting diodes merge.

  In the present invention, the dimming means is an ND filter that averagely reduces light in the visible light wavelength range, and the diffusing means is a diffusing filter having a diffusing characteristic that is equal to or approximates the diffusing characteristic of the light by a photographic film. It may be configured.

  With this configuration, the amount of light in the visible wavelength region can be reduced by the ND filter, and the light can be diffused by the diffusion filter.

  In the present invention, the dimming means is composed of an ND filter that averagely reduces light in the wavelength range of visible light, and at least one surface of the ND filter is equal to or approximates the light diffusion property of the photographic film. The ND filter may also be used as the diffusing means by finishing the surface with a diffusion characteristic.

  With this configuration, since the diffusing unit can be configured by the surface treatment of the ND filter, it is not necessary to use a special member as the diffusing unit, and the dimming unit and the diffusing unit formed as one member can be operated simultaneously.

The present invention includes an imaging optical system that forms an image of a photographic film irradiated with light from a light source unit on a photoelectric conversion surface of a photoelectric conversion unit with an optical lens, and transports the photographic film in the sub-scanning direction. A shading correction method for a film scanner that includes image data acquisition means that continuously captures image data in a region along the main scanning direction of a photographic film in association with each other, and that performs shading correction on the image data acquired by the image data acquisition means In
A diffusing means having a diffusing characteristic equal to or approximating the diffusing characteristic of the light beam by the photographic film; and a dimming means for reducing the amount of the transmitted light beam in the light path for guiding the light beam from the light source unit to the photoelectric conversion unit. It is configured to be switchable between a functional position to be arranged and a separation position to be separated from the optical path,
In a state where the diffusing unit and the dimming unit are set at the functional position at the same time, correction data is obtained based on light amount data along the main scanning direction obtained by the photoelectric conversion unit, and shading is performed based on the correction data. Correction may be performed.

  With this configuration, by setting the diffusing means and the dimming means at the functional positions, the diffusing means diffuses the light rays from the light source unit with characteristics equal to the diffusing characteristics of the photographic film, and the dimming means from the light source unit. The amount of light is reduced, and the correction data can be acquired without reflecting the total amount of light from the light source to the photoelectric conversion unit, reflecting the diffusion of light in the photographic film without using photographic film. Also, the photographic film can be scanned by setting the diffusing means and the dimming means at the spaced positions. As a result, appropriate shading data could be acquired without degrading the performance of the photoelectric conversion unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[Entire Configuration] As shown in FIG. 1, a film scanner that includes a light source unit A, a film carrier B, a lens unit C, a photoelectric conversion unit D, and a main control device E, and captures image information of a photographic film F as a digital signal. 1 is configured. As shown in the figure, the film scanner 1 transmits the acquired image data to the general-purpose computer 2, and the general-purpose computer 2 inputs necessary information from the keyboard 4 while displaying the image data on the display 3. Alternatively, image processing such as color correction is performed by using the mouse 5 as a pointing device, and order information necessary for print processing is generated and transmitted to the photographic printing apparatus 6 so as to print image data (FIG. The film scanner 1, the general-purpose computer 2, and the photo print device 6 constitute a photo processing system.

  The film scanner 1 is provided with a film carrier B corresponding to a plurality of types of photographic films F such as a 135 size, a 240 size, and a 120/220 size. Scanning corresponding to photographic film F of the size of The photographic printing apparatus 6 performs development processing after exposing a silver salt photographic paper as a print medium with a digital print head, or prints with a sublimation print head using a dedicated paper as a print medium. What is to be performed and those using an ink jet type print head are assumed.

  As shown in FIG. 2, the film scanner 1 irradiates the developed photographic film F supported by the film carrier B with the light beam from the light source unit A, thereby forming a zoom optical lens constituting the lens unit C. 41 is a CCD (Charge Coupled Device) type line sensor that guides a visible light image from a region along the main scanning direction of the frame image of the photographic film F to the photoelectric conversion unit D and passes through the splitter 47 of the photoelectric conversion unit D. At the same time, the infrared light image from the region along the main scanning direction of the frame image of the photographic film F is reflected by the splitter 47 of the photoelectric conversion unit D to form an image on the photoelectric conversion surface 45 for infrared light (IR). An image is formed on a photoelectric conversion surface of a CCD (Charge Coupled Device) type line sensor 46.

  At the time of scanning, the photographic film F set on the film carrier B is moved in the longitudinal direction (sub-scanning direction) in the transport path inside the film carrier B, and the photoelectric conversion unit D is photographed in synchronization with this movement. Image data converted into digital signals corresponding to the three primary colors of R (red), G (green), and B (blue) by sequentially capturing frame images of film F along the main scanning direction. (Image data corresponding to the frame image of the photographic film F) as the defect data (infrared light data) corresponding to the dust and scratches at the same time as the (visible light data) acquisition. Get the data.

  The image data and the defect data are transmitted from the main control device E to the general-purpose computer 2 and stored on a frame-by-frame basis in a storage such as a semiconductor memory or a hard disk provided in the general-purpose computer 2 (this storage process is performed). It may be performed by the main controller E). In addition, the general-purpose computer 2 performs a correction process for repairing the image data stored in the storage based on the defect data, and the processing mode is set so that the image data of the photographic film F can be output frame by frame. (This processing may be performed by the main controller E).

  [Light Source Unit] As shown in FIGS. 2 to 4, the light source unit A includes a plurality of light emitting diodes 10 (generic names of four types of light emitting diodes described later) for emitting the three primary colors and infrared light on a substrate P (described later). A light emitting diode array arranged linearly in the main scanning direction, and an illumination optical system for sending light rays from the light emitting diode array to the film carrier B side.

  More specifically, the light source unit A forms an internal space by overlapping an upper case 20 made of a resin molded product and a lower case 21 made of an aluminum alloy, and the light emitting diode array is formed in the internal space. Are provided on three substrates P (a general term for a first substrate P1, a second substrate P2, and a third substrate P3 described later). The internal space includes a cylindrical lens type collimating lens 22 that collimates the light beams from the respective light emitting diode arrays, and the converging optics that merges the light beams from the light emitting diode arrays sent through the collimating lens 22. The system includes a diffusion plate 23 that averages the combined light beams by diffusion and sends them to the film carrier B. Further, the substrate P is provided with heat-dissipating fins 24, and an electric fan 25 that supplies cooling air to the fins 24 is provided outside the lower case 21. In this film scanner, when acquiring correction data for shading correction, an ND filter G that can be set in an optical path (hereinafter referred to as a functional position) through which light rays from the light-emitting diode array are merged and sent. It has.

  A first substrate P1 and a second substrate P2 are supported on a bottom surface portion of the upper case 20, a third substrate P3 is supported on a side surface portion of the internal space, and a plurality of chip-shaped green substrates are formed on the first substrate P1. A green light emitting diode array in which the light emitting diodes 10G are linearly arranged in the main scanning direction is provided, and a plurality of blue light emitting diodes 10B in a chip shape are linearly arranged in the main scanning direction on the second substrate P2. A red / red LED having a blue light-emitting diode array, in which a plurality of chip-shaped red light-emitting diodes 10R and a plurality of chip-shaped infrared light-emitting diodes 10IR are alternately arranged in the main scanning direction on the third substrate P3. An external light emitting diode array is provided. Then, the collimating lens 22 is provided with the focal position set to the corresponding light emitting diode 10 so as to collimate the light from each light emitting diode array.

  The details of the substrate P (first substrate P1) will be described by taking a part having a green light emitting diode array as an example. As shown in FIG. 5, the surface of the aluminum base material 11 having high thermal conductivity is shown in FIG. Then, an insulating layer 12 made of a ceramic material or the like is formed, and a circuit board 13 on which printed wiring is formed is further formed on the insulating layer 12 to constitute a laminated substrate P. The fin 24 is attached to the back surface of the substrate P, and the chip-shaped light emitting diode 10 (10G) is linearly bonded to the surface of the circuit substrate 13 of the substrate P along the main scanning direction by die bonding. It is fixed. With respect to the surface of the circuit board 13, a frame body 14 that is rectangular in a direction perpendicular to the board surface and the reflector 15 are fixed in a posture parallel to the light emitting diode array formation direction (main scanning direction). Yes.

  The chip-like light emitting diode 10 provided on the circuit board 13 is electrically connected to a printed wiring 16 formed on the surface of the board P via a bonding wire 17, and is located near the light emitting diode array. A temperature sensor TS composed of a thermistor is provided. The frame 14 and the reflector 15 are integrally formed of a liquid crystalline polymer having excellent heat resistance, and the reflector 15 has a reflecting surface 15a inclined with respect to the side facing the light emitting diode 10. I have.

  The ND filter G is supported so as to be switchable between a functional position (position shown in FIG. 3) below the diffusion plate 23 and a separated position separated from the optical path, and from an electromagnetic solenoid type electric actuator 26. It is linked with a crank mechanism 27 that operates with a driving force of. The ND filter G functions as a dimming means that averagely reduces light in the visible wavelength range, and at the same time, finishes one surface (upper surface) of the ND filter G as a diffusing surface Ga. It functions as a diffusing means having a diffusing characteristic that is equal to or close to the diffusing characteristic of light rays by a photographic film. By setting this ND filter G at the functional position, the amount of light from the light source unit A is reduced, and at the same time, the diffusing surface Ga creates a state in which the light is diffused in the same manner as the photographic film F. This is sent out to the photoelectric conversion unit D through the lens 41.

  As shown in FIG. 2 and FIG. 3, when the central position in the direction of formation of the main optical path that sends light directly from below to the diffuser plate 23 is defined as the main optical axis L1, the green light emitting diode array The optical axis for sending out the light beam is made to coincide with the main optical axis L1, and a dichroic mirror type first mirror M1 that intersects the main optical axis L1 at a 45 degree posture in the direction shown in FIG. It is arranged. Further, when the center position in the formation direction of the sub optical path that guides the light beam in the direction of the main optical axis L1 by reflection at the first mirror M1 is set as the sub optical axis L2, the sub optical axis L2 is shown in FIG. A dichroic mirror type second mirror M2 is disposed that intersects the sub optical axis L2 in a 45 ° posture when viewed from the direction. The direction of formation of a converging optical path in which the optical axis for sending the light beam from the red / infrared light emitting diode array coincides with the sub optical axis L2, and the light beam is guided in the direction of the sub optical axis L2 by reflection at the second mirror M2. Is the merged optical axis L3, the optical axis of the blue light emitting diode array is made to coincide with the merged optical axis L3. The optical axis of the light emitting diode array coincides with a virtual straight line that is at the center position in the formation direction (main scanning direction) of each light emitting diode array and is perpendicular to the substrate P.

  The blue light emitting diode 10B has a wavelength of 400 to 480 nm, the green light emitting diode 10G has a wavelength of 520 to 560 nm, the red light emitting diode 10R has a wavelength of 620 to 750 nm, and the infrared light emitting diode 10IR has a wavelength of 830 to 950 nm. Things are used. The first mirror M1 has a performance of transmitting a light beam having a wavelength (520 to 560 nm) from the green light emitting diode 10G and reflecting a light beam having a wavelength other than this, and the second mirror M2 has a red light beam and a red light beam. Infrared light and light with a wavelength (620 to 750 nm and 830 to 950 nm) from the light emitting diodes 10R and 10IR are transmitted, and the light from the blue light emitting diode 10B (400 to 480 nm) is reflected. Yes.

  Then, the collimating lens 22 is arranged by setting a focus on the position of the light emitting diode 10G of the green light emitting diode array, and the focus is set on the position of the light emitting diode 10B of the blue light emitting diode array. The lens 22 is arranged, and the collimating lens 22 is arranged by setting a focal position on the light emitting diodes 10R and 10IR of the red / infrared light emitting diode array.

  [Film Carrier] The film carrier B includes a roller 30 that presses and conveys the developed photographic film F and a drive mechanism (not shown) that drives the roller 30. A cylindrical or toroidal condensing lens 31 is provided at a position for guiding a light beam to the formed scanning gate SG.

  As the diffusion plate 23, the length in the main scanning direction is sufficiently longer than the length of the light emitting diode array in the main scanning direction, and the width in the sub scanning direction is the width of the parallelizing lens 22 in the sub scanning direction. A beam shaping diffuser (LSD) of a size formed with a sufficiently larger width is used. The diffusion plate 23 is assumed to have a structure having a diffusion surface in which a number of fine protrusions are formed on the surface of a flat plate-shaped resin material, but a milky white resin plate may be used. .

  [Lens Unit and Photoelectric Conversion Unit] The lens unit C includes a zoom optical lens 41, a focusing motor (not shown) for focusing the optical lens 41, and a focal length of the optical lens 41. A zoom motor (not shown) to be set and sensors for obtaining a focus reference position and a zoom reference position (so-called home position) are provided, and an image of the photographic film F supported on the film carrier B is provided. An image is formed at an arbitrary magnification on the photoelectric conversion surfaces of the line sensors 45 and 46 built in the photoelectric conversion unit D.

  As shown in FIG. 2, the photoelectric conversion unit D senses infrared light (IR) and a three-line CCD line sensor 45 corresponding to the three primary colors R (red), G (green), and B (blue). And a dichroic mirror-type splitter 47 that transmits visible light from the optical lens 41 and reflects infrared light. Although not shown in the drawing, this photoelectric conversion unit D is based on a signal synchronized with the conveyance speed of the photographic film F, and signals from the three CCD line sensors 45 that detect visible light and infrared light. A signal from one CCD line sensor 46 that senses (IR) is A / D converted to the main controller E as image data of three primary colors of R (red), G (green), and B (blue). A processing circuit is provided for outputting to the main controller E as infrared light defect data by A / D converting a signal from the CCD line sensor 46 for sensing infrared light (IR). .

  [Control Configuration of Film Scanner] An outline of the control system of the film scanner 1 of the present invention can be shown as shown in FIG. That is, the main controller E is configured to be able to access signals to the photoelectric conversion unit D, the lens unit C, the film carrier B, and the light source unit A. The main control device E is configured to output control signals to the general-purpose computer 2 and input signals from the control signals. The general-purpose computer 2 receives image data and order data from the photo print device 6. It is configured to be able to transfer.

  When the image data of the photographic film F is acquired by the film scanner 1, the film carrier B is set in the main body of the film scanner 1 with the photographic film F set in the film carrier B suitable for the film size. Then, the processing for acquiring the image is executed by setting the number of pixels of the acquired image data. More specifically, the main control device E causes all the light emitting diodes 10 of the light source unit A to emit light and controls the lens unit C to have a value corresponding to the magnification that requires the focal length of the optical lens 41. Set and set the conveyance speed of the photographic film F on the film carrier B. After these settings, the conveyance of the photographic film F is started on the film carrier B, and the photoelectric conversion unit D is synchronized at each timing synchronized with the conveyance speed. The CCD line sensor 45 and the CCD line sensor 46 acquire line-shaped data (data along the main scanning direction), and the main processing unit E converts the acquired line-shaped image data into two-dimensional data. By developing, image data having a bitmap structure corresponding to the three primary colors of R (red), G (green), and B (blue), and infrared light (I It has become one can obtain defect data as a bitmap structure corresponding to).

  It should be noted that, based on the defect data (infrared light image data), a density adjustment process can be cited as an example of a specific processing mode of the correction process for repairing the defect. In addition, interpolation processing by the nearest neighbor method, bilinear method, bicubic method, or the like can be given as an example.

  At the time of acquisition of this image data, in the light source unit A, the light beam from the green light emitting diode array is collimated by the collimating lens 22 and transmitted through the first mirror M1 and sent out along the main optical axis L1. A light beam from the red / infrared light emitting diode array is sent out along the sub optical axis L2 in a state of being collimated by the collimating lens 22, and reflected by the first mirror M1 to be a light beam of the main optical axis L1. It is sent out in the state where it joins. Light rays from the blue light-emitting diode array are sent out along the merging optical axis L3 in a state of being collimated by the collimating lens 22, reflected by the second mirror M2, and merged with the sub-optical axis L2. Then, the light is reflected by the first mirror M1 and sent out in a state where it merges with the light beam of the main optical axis L1. The light beams of these wavelengths are mixed to become white light by being sent upward along the main optical axis L1, and further, the light distribution in the main scanning direction is averaged by being diffused by the diffusion plate 23. To do. The light beam from the light source unit A is condensed by the condensing lens 31 so as to be focused on the film surface of the photographic film F. As a result, the photographic film F can be efficiently illuminated with less waste of the light beam. It has become a thing.

  [Shading correction] In the light source unit A, since the plurality of light emitting diodes 10 are arranged in a row in the main scanning direction, the amount of light is not appropriate for any one of the plurality of light emitting diodes 10 constituting the light emitting diode array. In such a case, the variation in the amount of light affects the density of the image data. In addition, since the CCD line sensors 45 and 46 are also provided with a plurality of light receiving elements in the main scanning direction, variations in the performance of the respective light receiving elements affect the density of the image data. In order to eliminate such inconvenience, in the film scanner 1 of the present invention, the variation in the amount of light in the main scanning direction is acquired in advance to generate correction data. After the image data is acquired, the film scanner 1 is based on the correction data. Thus, by performing shading correction, the density of the image data is appropriately converted, and the light quantity variation in the main scanning direction of the light source unit A is eliminated, so that high-quality image data can be acquired.

  When this correction data is acquired, a large amount of light from the light source unit A directly irradiates the CCD line sensors 45 and 46 via the optical lens 41, so that the CCD line sensors 45 and 46 are damaged. It is also possible to reduce the performance. Further, since the photographic film F has a property of diffusing light rays, it is necessary to remove the influence of diffusion of light rays in the photographic film F during scanning. From this point of view, by using the ND filter G described above, the amount of light reaching the CCD line sensors 45 and 46 is reduced, and at the same time, correction data is acquired in a state where the diffusion surface Ga reproduces the diffusion of light rays by the photographic film F. Therefore, it is possible to acquire higher quality image data.

  [Control System] As shown in FIG. 7, the main control device E includes an input / output interface 61 that permits access to information and a microprocessor CPU that processes information from the input / output interface 61. The input / output interface 61 receives a signal from the temperature sensor TS via an A / D conversion circuit 62, and outputs a control signal to the fan 25 via a PWM type power control circuit 63. A control signal is output to the power supply circuit 64 that supplies power to the plurality of light emitting diodes 10 constituting the light emitting diode array of each of the three substrates P1, P2, and P3, and the control signal is output to the electric actuator 26. Then, a control signal is output to a lens control circuit 65 that performs focus adjustment (focus adjustment) and focal length adjustment (zoom adjustment) of the optical lens 41, and image data from the CCD line sensors 45 and 46 is input. Thus, a signal access system is formed. In the figure, only one temperature sensor TS, fan 25, and light emitting diode 10 are shown. However, the number of temperature sensors TS is equal to the number of substrates P, and six fans 25 are provided. A plurality of G, B, and IR light emitting diodes 10 are provided for the substrate P, and representative ones are shown in the drawing.

  In addition, a semiconductor memory 71 made of RAM or ROM, a data storage unit 72 made of EEPROM, a shading correction means 73 made of software, a correction data acquisition means 74 made of software, Temperature management means 75 made of software, lens control means 76 made of software, and image data acquisition means 77 made of software.

  The shading correction unit 73, the correction data acquisition unit 74, the temperature management unit 75, the lens control unit 76, and the image data acquisition unit 77 may be partially or entirely configured by hardware. In the main control device E, a signal system for accessing information to the photoelectric conversion unit D, the lens unit C, the film carrier B, and the general-purpose computer 2 is formed. Not shown.

  The data storage unit 72 stores the correction data corresponding to the four types of light-emitting diode arrays in an identifiable manner, and the shading correction unit 73 performs shading correction based on the correction data.

  The temperature management means 75 controls the rotation speed of the fan 25 based on the temperature of the substrate P measured by the temperature sensor TS, and controls the start and stop of the fan 25 to thereby control the temperature of the substrate P. Achieve control to maintain the target temperature. The lens control means 76 sets the focal length based on the size of the photographic film F and the number of pixels to be acquired, and adjusts the focus if necessary.

  The image data acquisition means 77 transports the photographic film F by the film carrier B as described above, and R (red) of the region along the main scanning direction of the photographic film F in the photoelectric conversion unit D at a timing synchronized with the transport. ), G (green), image data corresponding to B (blue) is acquired, and at the same time, defect data corresponding to infrared rays is acquired, and image data of a bitmap structure that becomes a two-dimensional image, and defect data The processing stored in the general-purpose computer 2 is realized.

  An outline of the control by the correction data acquisition means 74 can be shown as a flowchart of FIG. That is, in a state where the ND filter G is set at the functional position, all the light emitting diodes 10 emit light, and based on the measurement result from the temperature sensor TS, the temperature of the light emitting diodes 10 reaches the target temperature, and the light amount and wavelength are increased. Wait until stable (steps # 101 to # 103). Further, since the film scanner 1 includes the condensing lens 31 in the film carrier B, it is necessary to set the film carrier B not including the photographic film F at an appropriate position when acquiring correction data.

  After this standby, light quantity data (image data along the main scanning direction) along the main scanning direction of each of R, G, B, and IR is acquired from the CCD line sensors 45 and 46, and this light quantity data and a preset value are set. Based on the target light quantity data, correction data corresponding to R, G, B, and IR is generated and stored in the data storage unit 72 (steps # 104 and # 105).

  In the CCD line sensor 45, for example, when the light amount X in the main scanning direction acquired for the green (G) light is shown as shown in FIG. 10, the target light amount data Y has a constant light amount in the main scanning direction. It can be expressed as a linear graph that takes the following values. The target light quantity data Y is set independently for each of R, G, B, and IR, and the light quantity value indicated by each target light quantity data Y differs depending on the color balance. Yes.

  The correction data stored in the data storage unit 72 can be regarded as correction coefficient groups individually set corresponding to the light quantity data of the individual CCD elements constituting the CCD line sensors 45 and 46. The CCD line sensor The shading correction is realized by a calculation that multiplies the data acquired in 45 and 46.

  The shading correction is executed when the image data acquisition unit 77 acquires image data, and the outline of the processing form can be shown as a flowchart in FIG. That is, the focal length of the optical lens 41 is set, and when the ND filter G is at the functional position, it is set at the separated position (if it is already at the separated position, the separated position is maintained), and the photographic film F is placed on the film carrier B. Is set to start conveyance and perform scanning (Steps # 201 to # 203), and shading correction is performed based on the acquired R, G, B image data and correction data corresponding to IR defect data. The executed and corrected image data and defect data are temporarily stored in the semiconductor memory 71 in frame units, and then transmitted to the general-purpose computer 2 (steps # 204 and # 205).

  As described above, according to the present invention, the CCD line sensors 45 and 46 are directly irradiated with a large amount of light in order to reduce the amount of light from the light source unit A by using the ND filter G functioning as a dimming means. As a result, the CCD line sensors 45 and 46 are not degraded in performance and the like, and one surface of the ND filter G is finished to be a rough surface as the diffusion surface Ga, thereby being close to the light diffusion characteristics of the photographic film F. The light is diffused due to the characteristics, and correction data in a state reflecting the diffusion of the light by the photographic film F can be acquired without using the photographic film F. Further, since the ND filter G is switched between the functional position and the separated position by electrical control, it is not necessary to manually operate the ND filter G when acquiring correction data. Since it is arranged at a position relatively far from the position where F is conveyed, even if a fine unevenness is formed as the diffusion surface Ga, the optical lens 41 forms an image on the image plane on the CCD line sensors 45 and 46. Thus, inconveniences that cause unevenness can be avoided.

[Another embodiment]
The present invention may be configured as follows in addition to the embodiment described above.

(A) As shown in FIG. 11 (a), an ND filter G is used as the dimming means, and a diffusing filter H having a diffusing characteristic equal to or close to the diffusing characteristic of light rays by a photographic film is used as the diffusing means. G and the diffusion filter H are held in an overlapped form with the frame body 80 and integrated. By configuring in this way, not only can the ND filter G and the diffusion filter H be integrally operated, but also by replacing the diffusion filter H corresponding to a plurality of types of photographic film F, It becomes possible to acquire correction data by diffusing light rays with the diffusion characteristics of the kind of photographic film F, and by performing shading correction based on the correction data acquired in this way, better image data is obtained.

(B) As shown in FIG. 11 (b), the ND filter G is used as the dimming means and the diffusing means is closely attached to the diffusing filter H having a diffusing characteristic equal to or close to the diffusing characteristic of the light beam by the photographic film. Use in a combined form. Such integration makes handling easier.

(C) As the light source unit, a light emitting diode array using a halogen lamp to obtain red light and infrared light and using a plurality of light emitting diodes to obtain blue and green light rays is used.

Perspective view showing the configuration of a photographic processing system Perspective view of optical system of film scanner Longitudinal front view of the light source unit and film carrier Longitudinal side view of light source unit Cross section of substrate Block circuit diagram of the control system of the photo processing system Block circuit diagram of film scanner control system Correction data acquisition routine flowchart Shading correction routine flowchart Graph of light intensity and target light intensity data (A) is a sectional view of an ND filter and a diffusion filter of another embodiment, (B) is a sectional view of the ND filter and a diffusion filter of another embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Light emitting diode 10R Red light emitting diode 10G Green light emitting diode 10B Blue light emitting diode 41 Optical lens 73 Shading correction means 74 Correction data acquisition means 77 Image data acquisition means A Light source unit B Film carrier D Photoelectric conversion unit F Photo film G ND Filter H Diffusion filter

Claims (6)

An imaging optical system for forming an image of a photographic film irradiated with light from a light source unit on a photoelectric conversion surface of a photoelectric conversion unit with an optical lens, and linking with the conveyance of the photographic film in the sub-scanning direction A film scanner including an image data acquisition unit that continuously captures image data in a region along the main scanning direction of the film, and a shading correction unit that performs shading correction on the image data acquired by the image data acquisition unit. There,
A diffusing means having a diffusing characteristic equal to or approximating the diffusing characteristic of the light beam by the photographic film; and a dimming means for reducing the amount of the transmitted light beam in the light path for guiding the light beam from the light source unit to the photoelectric conversion unit. It is configured to be switchable between a functional position to be arranged and a separated position to be separated from this optical path,
Correction that generates correction data used for the shading correction based on light amount data along the main scanning direction obtained by the photoelectric conversion unit in a state where the diffusing unit and the dimming unit are set at the functional position at the same time. A film scanner provided with data acquisition means.   A film carrier for conveying the photographic film in the sub-scanning direction is provided at an intermediate position between the light source unit and the optical lens, and the diffusing unit and the dimming unit are separated from the functional position inside the light source unit. The film scanner according to claim 1, wherein the film scanner is switchable between positions.   The light source unit arranges a plurality of red light emitting diodes, a plurality of green light emitting diodes, and a plurality of blue light emitting diodes in the main scanning direction, and combines and sends out light beams from these light emitting diodes. The film scanner according to claim 2, wherein the functional position is set in an optical path.   The dimming means is composed of an ND filter that averagely reduces light in the wavelength range of visible light, and the diffusing means is composed of a diffusion filter having a diffusing characteristic that is equal to or close to the diffusing characteristic of light by a photographic film. The film scanner of any one of Claims 1-3.   The dimming means is composed of an ND filter that averagely reduces light in the wavelength range of visible light, and at least one surface of the ND filter has a diffusion characteristic surface that is equal to or approximates the light diffusion property of the photographic film. The film scanner according to claim 1, wherein the ND filter is also used as the diffusing unit by finishing. An imaging optical system for forming an image of a photographic film irradiated with light from a light source unit on a photoelectric conversion surface of a photoelectric conversion unit with an optical lens, and linking with the conveyance of the photographic film in the sub-scanning direction A film scanner shading correction method comprising image data acquisition means for continuously capturing image data of a region along the main scanning direction of the film, and performing shading correction on the image data acquired by the image data acquisition means,
A diffusing means having a diffusing characteristic equal to or approximating the diffusing characteristic of the light beam by the photographic film; and a dimming means for reducing the amount of the transmitted light beam in the light path for guiding the light beam from the light source unit to the photoelectric conversion unit. It is configured to be switchable between a functional position to be arranged and a separation position to be separated from the optical path,
In a state where the diffusing unit and the dimming unit are set at the functional position at the same time, correction data is obtained based on light amount data along the main scanning direction obtained by the photoelectric conversion unit, and shading is performed based on the correction data. A shading correction method for a film scanner that performs correction.

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