JP2000316071A - Film scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain reading with different resolution stably with a simple configuration in a film scanner of a configuration where an image pickup device applies main scanning to a film and subscanning is applied to the film with respect to the image pickup device. SOLUTION: As a configuration of a scanning mechanism to apply subscanning to a film 200 with respect to an image pickup device 113, a moving table 101 supporting the film 200 held in a film holder 201 and moving in the sub-scanning direction and a scanning mechanism to move this moving table in the sub-scanning direction are provided, and a step motor 107 driven by a pulse signal outputted from a drive circuit is employed for a drive source of the scanning mechanism. The step motor 107 is rotationally driven at a different pitch angle by selecting the pulse signal from the drive circuit to realize reading with a different resolution and the need for a variable speed unit is eliminated to simplify the structure and to reduce the cost.

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, and 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.

Incidentally, this type of film scanner is 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, some have a pre-scan function of reading at a low resolution to confirm a film image to be read before a main scan for reading a film image at a regular resolution. In such a case, the pitch dimension when reading a film image at each pitch position is usually changed while moving the film pitch, and in the case of a high-resolution main scan, the pitch dimension of the film movement is made minute. In the case of low-resolution pre-scan, the pitch dimension of the film movement is made coarse. For this reason, conventionally, a stepping motor as a driving force source of a moving mechanism for moving the moving table by a pitch, and a transmission including a variable speed reduction mechanism for switching the rotation output of the stepping motor are provided. A constant pulse is supplied to the motor per unit time to rotate the stepping motor at a constant pitch angle. On the other hand, in the main scan and the pre-scan, the speed ratio of the transmission is switched to change the moving pitch dimension of the moving table. Has been taken.

[0004]

However, in the film moving mechanism having such a structure, a gear mechanism including a plurality of gears is required to constitute a variable speed reduction mechanism as a transmission, and the gear ratio is changed. Therefore, a mechanism for switching the meshing state of the plurality of gears is required, and the film moving mechanism becomes complicated, which is an obstacle to downsizing and cost reduction of the film scanner.

SUMMARY OF THE INVENTION An object of the present invention is to provide a film scanner capable of simplifying the structure and enabling stable reading at high resolution and low resolution.

[0006]

According to the present invention, there is provided a film scanner for reading a film image by sub-scanning the film with respect to an image pickup device for main-scanning the film image. A moving table that moves in the sub-scanning direction; and a moving mechanism that moves the moving table in the sub-scanning direction. The moving mechanism includes a step motor as a driving force source, and the step motor having different rotation pitches. And a driving circuit for pulse driving. For example, the configuration is such that the step motor is driven to rotate at a basic pitch angle during the pre-scanning of the film, and the step motor is driven to rotate at a pitch angle smaller than the basic pitch angle during the main scanning of the film. In this case, the drive circuit outputs a first pulse signal for driving the step motor to rotate at a basic pitch angle and a second pulse signal for driving the step motor to rotate at a pitch angle smaller than the basic pitch angle. The first pulse signal is output when the film is pre-scanned, and the second pulse signal is output when the film is fully scanned. That is, specifically, the drive circuit is configured as a circuit that excites the step motor in 2-2 phase during the pre-scan of the film and excites the step motor in 1-2 phase during the main scan of the film. .

According to the present invention, by switching the pulse signal output from the drive circuit, the step motor can be driven to rotate at different pitch angles, and the moving table is moved at different pitch dimensions to achieve different resolutions. Can be read with a simple configuration, and downsizing of the apparatus can be realized.

[0008]

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 guide bars 102 are installed in a horizontal direction in an apparatus housing (not shown).
A movable table 101, which will be described in detail later, is movably mounted along. The moving table 101 holds a film holder 201 holding a film to be read. In addition, the two guide bars 10
The reading unit 110 is configured in a partial area in the length direction between the two. The reading unit 110 includes a diffusion light source 111 disposed at a position above the guide rail 102 and having a light emitting surface facing downward, and an imaging lens 11 disposed immediately below the diffusion light source 111 and at a position below the guide rail 102.
2 and a line sensor 113 composed of a CCD element for photoelectrically converting a film image formed by the photographing lens 112. The line sensor 113
The line direction is oriented in a direction orthogonal to the longitudinal direction of the guide bar 102. By reading in the line direction, the main scanning of the film is performed.

On the other hand, the guide bar 102 is penetrated on both sides of the moving table 101, and can be reciprocated along the guide bar 102 while sliding at the penetrating portions. Further, a rectangular reading window 103 is penetrated at a substantially central position of the moving table 101 in the thickness direction, and the film is read 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 can be moved along the extension direction of the rail 105. A rack 106 is integrally provided on one side surface of the moving table 101 along the longitudinal direction. The rack 106 is fixed to the apparatus housing in proximity to the one guide bar 102. Pinion 108 attached to the rotating shaft of scanning motor 107
Are engaged. The scanning motor 107
Uses a stepping motor that is driven to rotate by a pulse signal as described later.

The film 200 held by the film holder 201 is formed as a film strip obtained by cutting a 35 mm film into, for example, six frames.
The film holder 20 for holding the film 200
1 is formed in a strip shape slightly larger in size than the film 200, and a slit 2 for penetrating the film 200 in the longitudinal direction at substantially the center in the plate thickness direction.
02 is formed over the entire length. Six rectangular frame windows 203 corresponding to the slits 202 are arranged along the length of the film holder 201 and are opened in the thickness direction of the film holder 201. Needless to say, the frame window 203 is formed in a size and a pitch size corresponding to the frame of the image photographed on the film 200.

FIG. 3 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 121 controlled by a system control 120. Further, a film reading signal output from the line sensor 113 is amplified by an amplifier 122 and is converted by an A / D converter 123.
After the conversion into a digital signal, required image processing is performed in the image processing circuit 124 to generate a required image signal. The memory 125 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 127 via the interface circuit 126, and is connected to a personal computer (not shown). The light emission of the diffusion light source 111 is controlled by a light source driving circuit 128 controlled by the system control 120. In addition, the scanning motor 10
Numeral 7 is configured such that its rotation is controlled by a drive circuit 130 controlled by the system control 120.

FIG. 4 is a diagram showing a configuration of a motor driving circuit 130 for driving the scanning motor 107 to rotate at a pitch. Although not shown, the scanning motor 107 is provided with two phase coils for the rotor, and by controlling the phases of input signals 1φ to 4φ input to each phase coil, the rotation pitch thereof changes. Controlled. The motor drive circuit 130 includes a distribution circuit 131 for distributing the input pulse signal having a constant period, and the input signals 1φ to 4φ based on the pulse signals distributed by the distribution circuit 131.
An excitation circuit 132 for outputting excitation to the scanning motor 107 for excitation, a control circuit 133 for controlling distribution of a clock signal in the distribution circuit 131 in accordance with switching between prescan and main scan, and a distribution circuit 131 , And a motor power supply 135.

Therefore, in this motor drive circuit 130, when the pre-scan signal is input to the control circuit 133, the distribution of the clock signal by the distribution circuit 131 causes the excitation circuit 132 to output the signal shown in FIG. The phase timing signals 21φ to 24φ are output to the scanning motor 107. As a result, the scanning motor 107 is always driven by 2-2 phase excitation, which always performs two-phase excitation, and the scanning motor 107 is driven to rotate at a basic pitch angle twice as large as that in the case of the 1-2 phase excitation. Is done. On the other hand, when the main scan signal is input to the control circuit 133, the distribution circuit 131 distributes the clock signal, and the excitation circuit 132 scans the phase timing signals 11φ to 14φ shown in FIG. Is output to the motor 107 for use. As a result, the scanning motor 107 is driven by 1-2 phase excitation in which one-phase excitation and two-phase excitation are repeated, and the scanning motor 107 rotates at a half pitch angle which is half of the basic pitch angle. Driven.

The scanner operation using the film scanner having the above configuration will be described with reference to the flowchart of FIG. First, the film 200 to be read is the film holder 2
01 is inserted into the slit 202 of the film holder 201 and the frame image of the film is aligned with the frame window 203 of the film holder 201. Then, the film holder 201 is inserted between the rails 105 of the moving table 101, and the frame image of the film to be read is aligned with the reading window 103 of the moving table 101. When the film holder 201 is inserted (S
101), the scanning motor 107 is driven to move the moving table 101 to the initial position (S102, S10).
3, S104). At this time, the scanning motor 10
The pitch angle of 7 is not specified. This initial position is a state in which the moving table 101 has not yet reached the position of the reading unit 110. In this state, the diffusion light source emits light (S105), and this is detected by the line sensor 113.
The shading correction is performed in the image processing circuit 124 based on the received light (S106). continue,
The scanning table 107 is driven again to move the moving table 1.
01 is moved to the reading start position (S107). Then, the light transmitted through the frame window 103 of the moving table 101 is received by the line sensor 113, and the accumulation time of the CCD elements constituting the line sensor 113 is determined based on the received light amount (S108).

Next, the reading resolution is determined (S10).
9) In the case of the double resolution mode, for example, in the case of the main scan, the pulse signals 11φ to 14φ output from the excitation circuit 132 by the switching signal of the motor drive circuit 130
Is supplied to the scanning motor 107 to perform step driving. As a result, the scanning motor 107 is excited in one or two phases, and is driven to rotate at a half pitch angle of the basic pitch angle. The pinion 108 is rotated by the rotation of the scanning motor 107, and the movable table 101 is engaged with the rack 106 of the movable table 101.
1 is moved by one frame along the guide bar 102 while step-moving by 1/2 pitch. The moving state at this time is from the state of FIG. 7A to the state of FIG. 7B, and the moving distance at a predetermined number of pitches is X1. This allows
A main scan is performed on the frame image of the film 200 by the line sensor 113, and a sub-scan is performed by moving the moving table 101. As a result, a main scan at a high resolution (double resolution) is performed (S110). Next, the completion of the reading is determined (S111), and if not, the reading from step S107 is repeated.

On the other hand, if the mode is not the double resolution mode in step S109, for example, in the case of pre-scan, the excitation circuit 132 of the motor drive circuit 130 supplies pulse signals 21φ to 24φ to the scan motor 107. As a result, the scanning motor 107 is excited by the 2-2 phase and is driven to rotate at a basic pitch angle, that is, is driven to rotate at twice the pitch angle as compared with the above-described main scan. The scanning motor 10
By the rotation of 7, the pinion 108 is rotated, and the movable table 101 is moved by one frame along the guide bar 102 while being stepped at the basic pitch dimension by meshing with the rack 106 of the movable table 101. Therefore, when the scanning motor 107 is driven by the predetermined number of pitches, the moving table 101 is moved by twice the moving distance X2 as shown in FIG. 7C, and the scanning of the frame image of the film at low resolution is performed. Done. (S112).

Next, the completion of reading is determined in the same manner as described above (S116).
Rotating the scanning motor 107 to move the moving table 1
01 is returned to the initial position (S113, S114), and the scanning motor 107 is stopped (S115). After that, the detailed description is omitted, but the film holder 20
Reading is completed by taking 1 out of the moving table 101. When reading another frame image of the film, the other frame image is aligned with the reading window of the moving table, and the above-described process is performed. In this case, step S109 is performed by setting a program. It is possible to configure to perform the steps from.

Here, when one main scan is performed as described above, the moving table 101 is in a state of being moved in the distal direction. Therefore, in the case of the next main scan and pre-scan, the moving table 101 reciprocates in the sub-scanning direction opposite to the above. In this case, it is possible to control the moving table 101 to return to the initial position every time one main scan is performed. However, when scanning is performed while continuously moving frames, the entire scan time is reduced. It will take.

As described above, in the case of a main scan or the like that requires a high resolution, the scanning motor 107 is driven to rotate at a half pitch angle of the basic pitch angle, and the moving table 101 is moved to a small pitch size. In the case of pre-scanning or the like where high resolution is not required, the scanning motor 107 is driven to rotate at the basic pitch angle, and the moving table is step-moved with a large pitch dimension to move the film in the stepwise direction. By performing sub-scanning, film reading at different resolutions can be realized by one motor and one moving table scanning mechanism. Therefore, the structure of the scanning mechanism can be simplified, and the size and cost of the film scanner can be reduced.

Here, in the above embodiment, examples of pre-scanning and main scanning have been described as examples of reading high resolution and low resolution. However, the present invention is not limited to this. The same applies to a film scanner configured to read at twice the resolution.

In the above-described embodiment, the line sensor is of a one-line type. However, if an RGB three-line type is used, an image signal of each color of RGB can be obtained on three lines. Therefore, the sub-scan of the pre-scan and the main scan described above can be completed only once, which is effective in further reducing the scan time. Further, it is needless to say that the ratio of the pitch angle of the motor in the main scan and the prescan is not limited to 1: 2 in the above-described embodiment.

[0022]

As described above, according to the present invention, as a configuration of a scanning mechanism for sub-scanning a film with respect to an image sensor, a moving table which supports a film and moves in the sub-scanning direction, And a moving mechanism for moving the stepping motor in the sub-scanning direction, and the moving mechanism includes a stepping motor as a driving force source and a driving circuit for rotating the stepping motor at different pitch angles. By switching the output pulse signal, the step motor can be driven to rotate at different pitch angles. As a result, the moving table can be stepped at different pitch dimensions and read at different resolutions without the need for a transmission, so that the configuration of the film scanner can be simplified and reading at a stable sub-scanning speed can be achieved. And high quality reading can be realized.

[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 block diagram illustrating an electric circuit configuration of the film scanner.

FIG. 4 is a circuit configuration diagram illustrating an example of a motor drive circuit.

FIG. 5 is a timing chart of pulse signals input to a scan motor (step motor) during a main scan and during a prescan.

FIG. 6 is a flowchart for explaining a film scanning operation.

FIG. 7 is a schematic side sectional view showing operations of a main scan and a prescan.

[Explanation of symbols]

 101 moving table 102 guide bar 103 reading window 105 rail 106 rack 107 scanning motor 108 pinion 110 reading unit 111 diffused light source 112 imaging lens 113 line sensor (CCD element) 120 system control 130 motor drive circuit 131 distribution circuit 132 excitation circuit 133 control Circuit 134 Power supply circuit 135 Motor power supply 200 Film 201 Film holder 202 Slit 203 Frame window

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H012 BA08 BA11 2H106 AB35 AB45 AB70 BA11 5C062 AA05 AB03 AB17 AB32 AC11 BA01 5C072 AA01 BA02 NA01 NA02 NA05 NA06 VA03 WA04 XA10 5H580 AA04 BB09 CA12 CB03 CB04 FA14 FC06 GG04 KK04 KK04

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 moving mechanism that moves the moving table in the sub-scanning direction.
The film scanner according to claim 1, wherein the moving mechanism includes a step motor as a driving force source, and a driving circuit for pulse-driving the step motor at different pitch angles. 2. The method according to claim 1, wherein the step motor is driven to rotate at a basic pitch angle when the film is pre-scanned, and the step motor is driven to rotate at a pitch angle smaller than the basic pitch angle during a main scan of the film. The described film scanner. 3. A driving circuit comprising: a first pulse signal for rotating the step motor at a basic pitch angle; and a second pulse signal for rotating the step motor at a pitch angle smaller than the basic pitch angle. Each output is possible, and when the film is pre-scanned, the first
And the second pulse signal is output during the main scanning of the film.
The film scanner according to 1. 4. The drive circuit excites the step motor during a pre-scan of the film in a 2-2 phase mode, and activates the step motor during the main scan of the film by one.
4. The film scanner according to claim 3, wherein the film scanner is a circuit for performing two-phase excitation. 5. The moving table, wherein a film holder for holding the film is detachably provided, and a film image to be read is switched by changing a mounting position of the film holder with respect to the moving table. 5. The film scanner according to any one of 4. 6. The moving mechanism includes a rack provided on the moving table along the sub-scanning direction, and a pinion attached to a rotating shaft of the stepping motor and meshing with the rack. 6. The film scanner according to any one of claims 1 to 5.