JP2001051360A - Film scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reading speed of a prescanning for reading at coarse pitch size in a film scanner constituted so that film may be main-scanned by an imaging device and sub-scanned with respect to the image pickup device. SOLUTION: This film scanner is equipped with a moving table 101 moving in a subscanning direction while supporting the film, a lead screw 121 extended along the table 101 and provided with a screw groove 124 engaged with the table 101, and a step motor 122 driving and axially rotating the screw 121 as the constitution of a scanning mechanism for subscanning the film 200 with respect to the imaging device 113. The screw 121 is divided to plural areas in its longitudinal direction, and 1st and 2nd pitch screw grooves 124A and 124B having different pitch size are formed in the respective areas. By selecting two screw grooves and screwing the lead body 123 of the table 101, the table 101 is moved in the subscanning direction at the different pitch size corresponding to the selected pitch size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film scanner for reading an image photographed on a silver halide film by a photoelectric conversion element and converting the image into an image signal.

[0002]

2. Description of the Related Art With the spread of personal computers (personal computers) in recent years, images taken by a digital still camera and images scanned by a scanner device are taken into a personal computer and subjected to image processing or recording. I have. In response to the demands of such an era, it has been considered that an image photographed by a photographic film such as a silver halide film is taken into a personal computer. Conventionally, a photographed image printed is read by a scanner device. However, in this type of scanner, it is necessary to read after printing on a print, so that a negative image without printing or a positive image on a positive film cannot be read. Therefore, a film scanner for directly reading a negative image or a positive image on a photographic film has been proposed. Such a film scanner is basically the same as a conventional scanner device, in which a film image is main-scanned by a line sensor including a photoelectric conversion element such as a CCD element, and the film or the line sensor is moved in the main scanning direction. The configuration is such that sub-scanning is performed by moving in the sub-scanning direction orthogonal to the sub-scanning direction.

In this type of film scanner, it is sometimes required to read a film image at different resolutions. For example, high-resolution reading is performed when precise image data is desired, and low-resolution reading is performed when the storage capacity of the personal computer is small. Alternatively, a pre-scan function for reading at a low resolution to confirm a film image to be read is provided before a main scan for reading a film image at a regular resolution. When reading at such different resolutions, the pitch dimension in the sub-scanning direction when reading a film image is usually changed, and in the case of high-resolution main scanning, the pitch dimension of the film movement is minute. In the case of a low-resolution pre-scan, the pitch dimension of the film movement is made coarse.

In order to realize reading at such different pitch dimensions, it is required to have a moving mechanism for moving the film in the sub-scanning direction at different pitch dimensions between the main scan and the prescan. For example, it is conceivable to change the rotation speed or rotation pitch of a motor as a drive source of the film moving mechanism between the main scan and the prescan. However, in order to perform such electrical control, it is inevitable that the structure is complicated by a motor drive circuit and components attached thereto. On the other hand, a configuration is conceivable in which the pitch dimension of the film movement is set to a minute pitch dimension of the main scan, and the reading is performed while performing so-called thinning at every natural multiple of the pitch of the main scan during the prescan. With this configuration, it is possible to realize the main scan and the prescan having different reading resolutions while moving the film at the pitch dimension of the main scan, which is advantageous in simplifying the configuration.

[0005]

However, in the film scanner having such a configuration, since the film moving speed itself is the same between the main scan and the pre-scan, the time required to complete the pre-scan reading is shorter than the actual time. Same as scan. Therefore, although the prescan has a smaller read pitch size than the main scan, the time required to complete reading of the same image is almost the same as that of the main scan. Therefore, even in the case where a pre-scan for confirming the target film image is performed before the main scan, the same reading time as that of the main scan is required, and high-speed reading of the pre-scan cannot be realized. There's a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a film scanner which achieves high-speed prescan reading while simplifying the structure.

[0007]

According to the present invention, there is provided an image pickup device for main scanning a film on which an image has been visualized to read the image, and a sub-scanning device which is perpendicular to the main scanning direction with respect to the image pickup device. In a film scanner having a scanning mechanism that moves in the scanning direction, the scanning mechanism includes a moving table that supports the film and moves in the sub-scanning direction, and a table driving mechanism that moves the moving table in the sub-scanning direction. The table driving mechanism includes a lead screw extending along the moving table and provided with a screw groove engaged with the moving table, and a step motor for driving the lead screw to rotate around the axis. The lead screw is divided into a plurality of regions in the longitudinal direction, and the pitch dimension of the screw groove is different in each region.

In a preferred embodiment of the present invention, the screw groove is divided into two regions in the longitudinal direction, a first pitch screw groove having a predetermined pitch dimension is formed in one region, and the first pitch screw groove is formed in the other region. A second pitch screw groove having a larger pitch dimension than one pitch screw groove is formed, and the first and second pitch screw grooves are formed continuously with each other. In the present invention, a film holder for holding the film is detachably provided on the moving table, and the film holder is moved in the sub-scanning direction to set a frame position of the image with respect to the moving table. Is provided. Further, in the present invention, means for detecting an initial position of the moving table is provided, and the moving table is moved relative to the first pitch screw groove or the second pitch screw groove with reference to the detected initial position of the moving table. It is configured to be selectively engaged.

According to the above construction of the present invention, the stepping motor of the table driving mechanism rotates the lead screw at a predetermined rotational angular velocity, and selects the screw grooves provided on the lead screw with different pitch sizes to set the moving table. By the engagement, the moving table and the film loaded therein are moved in the sub-scanning direction at a pitch size according to the selected pitch size, that is, at a different pitch size. Therefore, by selecting a screw groove, high-resolution reading can be performed by performing a main scan with a fine pitch dimension, and high-speed prescan can be realized by performing a prescan with a coarse pitch dimension.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a conceptual configuration of a film scanner of the present invention, and FIG. 2 is a partially exploded perspective view thereof. Two parallel guide bars 102 are erected horizontally along the sub-scanning direction in an apparatus housing (not shown), and a movable table 101, which will be described in detail later, is movably mounted along the guide bars 102. It is suspended. The moving table 101 holds a film holder 201 holding a film to be read. Further, a reading unit 110 is formed in a partial area in the length direction between the two guide bars 102. The reading unit 110 includes:
A diffused light source 111 disposed above the guide rail 102 and having a light emitting surface directed downward;
RGB (red, green, and blue) line sensors each including an imaging lens 112 disposed directly below the guide rail 102 and below the guide rail 102, and a CCD element that photoelectrically converts a film image formed by the imaging lens 112. And a line sensor 113 composed of The line sensor 113 has a line direction oriented in a direction orthogonal to the longitudinal direction of the guide bar 102, and performs main scanning of the film by reading in the line direction.

On the other hand, the moving table 101 is formed to have a length in which two or more frame images of a film to be read can be arranged in the sub-scanning direction. Is penetrated, and is reciprocally movable along the guide bar 102 while sliding at the penetrating portion. At the substantially center position of the moving table 101, as described above, a reading window 103 formed elongated along the length direction so as to include two or more frame images of the film in the sub-scanning direction. The film image is read through the reading window 103 by the line sensor 113 through the reading window 103. Further, a holder holding rail member 104 whose both sides are bent as L-shaped rails 105 along both sides of the reading window 103 is fixed to the upper surface of the moving table 101. The film holder 201 is held between the rails 105, and the film holder 201 is
It is possible to move along the extension direction.

Further, the holder holding rail member 104
In one of the side surfaces of one of the rails 105, a window 105 is provided.
a is opened, and a frame feed motor 106 is supported above the window 105a. A pinion 107 is attached to a rotation shaft of the frame feed motor 106, and a part of the pinion 107 is The rail 105 is exposed through the window 105a.

On one side of the moving table 101, there is provided a table driving mechanism 120 as a sub-scanning mechanism for reciprocating the moving table 101 along the guide bar 102. The table drive mechanism 120
Is a lead screw 121 extending in parallel with the guide bar 102 along one side of the moving table 101, and a scanning step motor (hereinafter simply referred to as a step motor) for driving the lead screw 121 for axial rotation. 122) and the lead body 1 connected to a part of the moving table 101 and engaged with the lead screw 121.
23. FIG. 3 is a partial side view thereof,
The lead screw 121 is formed with a screw groove (spiral groove) 124 over substantially the entire length, and the lead body 123 has an elongated spring piece 123a whose base end is integrally fixed to the moving table 101; Spring piece 1
An engagement protrusion 123b is attached to the distal end of the screw groove 23a and has a spherical distal end and is engaged with the screw groove 124. Therefore, the step motor 122
When the lead screw 121 is driven to rotate in the axial direction, the lead body 123 is engaged with the engagement protrusion 123b by the screw groove 12.
4, the moving table 101 integrated with the lead body 123 is moved in the sub-scanning direction along the guide bar 102. Here, the lead screw 121 is divided into two regions in the longitudinal direction, and a screw groove 124a in a tip region located on the opposite side to the step motor 122 is a first pitch screw groove 124A having a predetermined pitch dimension P. Although formed, the screw groove 124B in the base end region on the side of the step motor 122 is formed as a second pitch screw groove having a pitch dimension 2P twice as large as that. The first pitch screw groove 124
A and the second pitch screw groove 124B are formed as continuous screw grooves at the boundary.

Therefore, the table driving mechanism 120
Then, even if the step motor 122 is driven to rotate at a constant rotational angular speed and the lead screw 121 is driven to rotate at a constant angular speed, the lead body 123 provided on the moving table 101 engages with the first pitch screw groove 124A. In this case, the moving table 101 is moved in the sub-scanning direction at a pitch dimension corresponding to the pitch dimension P, that is, at a fine pitch. Further, when the lead body 123 is engaged with the second pitch screw groove 124B, the moving table 101 is moved in the sub-scanning direction at a pitch dimension according to the pitch dimension 2P, that is, at a coarse pitch and at a high speed. Will be. The moving table 101
Is the dimension obtained by dividing the pitch dimension of each screw groove 124 by the number of steps when the step motor 122 makes one rotation.

Further, a light-shielding piece 131 is formed integrally with one end of one side of the moving table 101, and the light-shielding piece 1 is moved with the movement of the moving table 101.
The photointerrupter 132 is located on a part of the trajectory
Are arranged, and the light shielding plate 131 is configured to be photoelectrically detected. Although not shown, the photointerrupter 132 is a pair of a light emitting element and a light receiving element, and receives light emitted from the light emitting element by the light receiving element.
Needless to say, the detection is performed when the light receiving element blocks light reception by the light shielding plate. The photo interrupter 132 detects the light shielding plate 131 when the moving table 101 is moved to a predetermined position, here, the initial position of the moving table 101, and detects the detection signal to detect the initial position of the moving table 101. It is configured to output as a signal.

The film 200 held by the film holder 201 is formed as a film strip obtained by cutting a 35 mm film, for example, every six frames. Is formed in a strip shape having a slightly larger dimension, and a slit 202 for penetrating the film 200 in the longitudinal direction is formed at substantially the center in the plate thickness direction over the entire length. Also,
6 rectangular window 2 corresponding to the slit 202
Numerals 03 are arranged along the length direction of the film holder 201, and are opened in the thickness direction of the film holder 201. Further, on one side of the film holder 201,
A rack 204 is formed in the longitudinal direction, and the rack 204 is mounted on the rail 10 of the moving table 101.
5, the frame feed motor 106 is inserted through a window 105a opened in a part of the rail 105.
And is reciprocally moved in the sub-scanning direction on the moving table 101 by a rack and pinion mechanism using the frame feed motor 106 as a rotational drive source. It is needless to say that the frame window 203 is formed to have dimensions and intervals corresponding to the frames of the image photographed on the film 200.

FIG. 4 shows an electric circuit configuration of the film scanner. 1 and 2 are denoted by the same reference numerals. The line sensor 113 includes:
It is driven by a line sensor drive circuit 141 controlled by the system control 140. A read signal of the film output from the line sensor 113 is amplified by an amplifier 142 and is converted into an A / D converter 143.
After the conversion into a digital signal, the image processing circuit 144 performs required image processing to generate a required image signal. The memory 145 stores an image signal subjected to image processing, and is configured by, for example, an IC card. The image signal is output to the input / output terminal 147 via the interface circuit 146 and connected to a personal computer (not shown). The light emission of the diffusion light source 111 is controlled by a light source driving circuit 148 controlled by the system control 140. The frame feed motor 106 and the step motor 122 are connected to the system control 14.
0 controls the rotation.

The scanning operation of the film scanner having the above configuration will be described with reference to the flowchart of FIG. First, the step motor 122 is driven to set the moving table 101 to the initial position (S101). In this setting of the initial position, as described above, the photo interrupter 1
32 is performed so as to detect the position of the light shielding plate 131. When it is confirmed that the moving table 101 is at the initial position (S102), the step motor 122 is stopped (S103). Next, it is detected whether or not the film holder 201 is loaded on the moving table 101 (S10).
4) If the film holder 201 is loaded, a holder pull-out warning is issued (S105), and the film holder 201 is detached from the moving table 101.
When the film holder 201 is not loaded, the diffusion light source emits light (S106), and the light is received by the line sensor 113. Based on the received light, the image processing circuit 14
In step 4, shading correction is performed (S107).

Next, it is determined whether or not the film holder 201 is loaded on the moving table 101 (S10).
8) If it is not loaded, it is determined whether or not to terminate the processing (S109). If not, the process waits for the film holder 201 to be loaded on the moving table 101. When the film holder 201 is loaded on the moving table 101, the setting of the main scan or the pre-scan is determined (S110). When the setting is made, it is determined whether the setting is the main scan or the pre-scan (S11).
1). In the case of pre-scan, the lead body 123 is
The step motor 122 is driven to move to a position where it engages with the base end of the pitch screw groove 124B (S1).
12). Next, this time, the frame feed motor 106 is driven,
The film holder 201 is moved in the sub-scanning direction on the moving table 101 by the rack and pinion mechanism, and the leading end of the frame of the film to be read is positioned on the line sensor 113 (S113). Then, the CCD accumulation time is determined based on the output of the line sensor 113 (S114).
Next, by driving the step motor 122 to rotate the lead screw 121, the moving table 101 is moved at high speed together with the lead body 123 at a coarse pitch according to the pitch dimension 2P of the second pitch screw groove 124B. As a result, the film image in the frame of the film holder 201 is sub-scanned by the line sensor 113 while being illuminated by the diffusion light source 111, and high-speed reading with a coarse pitch is performed (S115). In this reading, reading in each of R, G, and B colors is performed.

If the main scan is set in step S111, the lead body 123 is positioned at the base end of the first pitch screw groove 124A, in other words, at the boundary with the second pitch screw groove 124B. The step motor 122 is driven to move to a position where it engages with the one pitch screw groove 124A (S116). Next, as in the case of the prescan, the frame feed motor 106 is driven,
The film holder 201 is moved in the sub-scanning direction on the moving table 101 by the rack and pinion mechanism, and the leading end of the film frame to be read is positioned on the line sensor 113 (S117). Then, the CCD accumulation time is determined based on the output of the line sensor 113 (S118).
Then, by driving the step motor 122 to rotate the lead screw 121, the moving table 101 is moved at a fine pitch according to the pitch dimension P of the first pitch screw groove 124A. As a result, the film image in the frame of the film holder 201 is sub-scanned by the line sensor 113, and reading at a fine pitch is performed (S119). In this reading, reading in each of R, G, and B colors is performed.

After the above reading is completed, it is determined whether or not the next scan is to be performed. If no subsequent scan is to be performed, it is determined whether or not the reading is to be terminated. The process returns to step S110 (S120). When the reading is completed, the stepping motor 12
2 is driven (S121), the moving table is moved to the initial position (S122), and then the stepping motor is stopped (S123). Thereafter, the operator can pull out the film holder 201 from the moving table 101 and terminate the reading.

As described above, in the film scanner of the above-described embodiment, the second pitch screw groove 1 having a large pitch dimension of the lead screw 121 at the time of pre-scanning while driving the step motor 122 at a constant rotational angular velocity.
24B, the moving table 101 and the film holder 2 are moved in the sub-scanning direction.
01 is moved at a high pitch in one of the sub-scanning directions, that is, at a coarse pitch and at a high speed, and a high-speed pre-scan is executed. During the main scan, the moving table 101 is moved in the sub-scanning direction by using the first pitch screw groove 124A having a small pitch dimension of the lead screw 121. Therefore, the moving table 101 and the film holder 201 are moved in the opposite direction to the sub-scanning direction. The main scan is executed at a high resolution.

As a result, it is possible to speed up the reading in the prescan, and it is possible to at least achieve the purpose of confirming the film image at high speed among the original purposes of performing the prescan. In this embodiment, the switching between the pre-scan and the main scan is performed by driving the step motor 122 so that the lead member 123 provided on the moving table 101 moves the first pitch screw groove 124A.
Alternatively, since it is possible by engaging with one of the second pitch screw grooves 124B, a mechanism for switching is unnecessary, and the configuration of the table driving mechanism can be simplified.

In the above-described embodiment, an example is shown in which the ratio of the pitch dimension of the first pitch screw groove 124A to the pitch dimension of the second pitch screw groove 124B is set to 2: 1 between the prescan and the main scan. The present invention is not limited to this value, but may be set to an arbitrary ratio, and in particular, the prescan pitch dimension may be set to an arbitrary value from the relationship between required resolution and reading speed. In the above-described embodiment, examples of pre-scanning and main scanning have been described as examples of reading high-resolution and low-resolution film images.
However, the present invention is not limited to this, and can be similarly applied to a film scanner configured to read a scan at both a resolution of 1 and a resolution that is a multiple of a natural number thereof.

[0025]

As described above, according to the present invention, as a configuration of a scanning mechanism for moving a film in the sub-scanning direction in order to read a film image, a moving table for supporting the film and moving in the sub-scanning direction, A table driving mechanism for moving the table in the sub-scanning direction, the table driving mechanism extending along the moving table and having a lead groove provided with a screw groove engaged with the moving table; And a step motor that drives the shaft to rotate. The lead screw is divided into a plurality of regions in the longitudinal direction, and the pitch dimension of the screw groove is different in each region. Therefore, according to the present invention, the lead screw is rotated at a predetermined angular velocity by the step motor of the table driving mechanism, and the moving table is engaged by selecting screw grooves having different pitch dimensions provided on the lead screw. Accordingly, the moving table and the film loaded therein are moved in the sub-scanning direction at a pitch size according to the selected pitch size, that is, at a different pitch size. This makes it possible to realize a film scanner capable of high-speed reading by performing pre-scanning with a coarse pitch while enabling main scanning with a fine pitch to perform high-resolution reading.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an overall configuration of an embodiment of a film scanner of the present invention.

FIG. 2 is a partially exploded perspective view of FIG.

FIG. 3 is a side view of a part of a lead screw of the table driving mechanism.

FIG. 4 is a block diagram showing an electric circuit configuration of the film scanner.

FIG. 5 is a flowchart for explaining a film scanning operation.

[Explanation of symbols]

 REFERENCE SIGNS LIST 101 moving table 102 guide bar 103 reading window 105 rail 106 frame feed motor 107 pinion 110 reading unit 111 diffused light source 112 imaging lens 113 line sensor (CCD element) 120 table driving mechanism (sub-scanning mechanism) 121 read screw 122 step motor 123 Lead body 124 Screw groove 124A First pitch screw groove 124B Second pitch screw groove 140 System control 200 Film 201 Film holder 202 Slit 203 Frame window 204 Rack

Claims (6)

[Claims] 1. An image sensor for reading an image by main-scanning a film on which an image has been visualized, and a scanning mechanism for moving the film relative to the image sensor in a sub-scanning direction orthogonal to the main scanning direction. In the film scanner comprising, the scanning mechanism includes a moving table that supports the film and moves in the sub-scanning direction, and a table driving mechanism that moves the moving table in the sub-scanning direction. The table driving mechanism includes a lead screw that extends along the moving table and is provided with a screw groove that engages with the moving table, and a step motor that drives the lead screw to rotate axially. The film is divided into a plurality of regions in the longitudinal direction, and the pitch dimension of the screw groove is different in each region. Scanner. 2. The screw groove is divided into two regions along a longitudinal direction of the lead screw, a first pitch screw groove having a predetermined pitch dimension is formed in one region, and the first pitch screw groove is formed in the other region. The second pitch screw groove having a larger pitch dimension than the first pitch screw groove is formed, and the first and second pitch screw grooves are formed continuously with each other. Film scanner. 3. A lead body comprising a spring piece having a fixed base end and an engagement projection engaged with the screw groove is provided at the tip of the moving table, and the lead body is provided with the lead. The film scanner according to claim 2, wherein the film scanner is moved in the longitudinal direction of the lead screw while being guided by the screw groove as the screw rotates. 4. The moving table is removably provided with a film holder for holding the film, and moves the film holder in the sub-scanning direction to set a frame position of the image with respect to the moving table. 4. The film scanner according to claim 1, further comprising a frame feed mechanism. 5. The frame feed mechanism includes a frame feed motor supported by the moving table, a pinion attached to a rotation shaft of the motor, and a pinion provided on one side of the film holder and meshing with the pinion. 5. The film scanner according to claim 4, wherein the film scanner comprises a rack. 6. A means for detecting an initial position of the moving table, wherein the moving table is selected with respect to the first pitch screw groove or the second pitch screw groove based on the detected initial position of the moving table. The film scanner according to any one of claims 1 to 5, wherein the film scanner is engaged with the film scanner.