JP2001154280A - Image reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a filter switching function which is inexpensive and compact and whose power consumption is low. SOLUTION: An optical filter holding frame is turnably supported, and energizing force is previously applied to the optical filter holding frame by a toggle spring. A projection part is formed at a scanning part for scanning the image of a transmissive original, and the optical filter holding frame is turned by the energizing force by the toggle spring after the projection part abuts on the optical filter holding frame when the scanning part is moved, whereby the optical filter is switched interlocked with the movement of the scanning part without using a dedicated actuator for switching the optical filter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image reading technique for reading an image of a transparent original such as a developed photographic film.

[0002]

2. Description of the Related Art Conventionally, in a film image reading apparatus (hereinafter, referred to as a film scanner) for reading an image of a transparent original such as a developed photographic film, generally, a film is transmitted from behind a transparent original such as a microfilm or photographic film by an illumination optical system. A document is irradiated, the transmitted light is projected and formed on an image forming surface of a photoelectric conversion element via a projection optical system, and the optical image is converted into an electric image signal by the photoelectric conversion element.

There is known a film scanner of this type which reads and outputs an image by inserting and removing a plurality of optical filters in the middle of an optical path according to various purposes. For example, U.S. Pat. No. 4,922,333 discloses an example in which color filters of R (red), G (edge), and B (blue) are alternately put in and taken out of a photoelectric conversion element for detecting black and white, and an image of each color is sequentially read. ing.

In Japanese Patent Publication No. 6-78992,
In order to illuminate a film with infrared light to detect dust and dirt, an image is read by alternately inserting and removing an infrared cut filter and a parent light cut filter in an optical path.

[0005] Such an optical filter switching device including the above-mentioned conventional example is constituted by a turret system in which an optical filter holding frame is rotatable.

FIG. 10 is a view showing a filter replacement mechanism disclosed in Japanese Patent Publication No. 6-78992. In the drawing, reference numeral 135 denotes an optical character filter holding frame. Optical filter holding frame 135
Has five holes, 135b is a through hole, and 135c has an R (red) transmission filter.
G (green) transmission filter for 35d, B for 135e
A (blue) transmission filter is provided, and an R (infrared) transmission filter is disposed at 135f.

Reference numeral 136 denotes a motor, and an output gear 136 is attached to an output shaft of the motor. The output gear 136 is engaged with a gear cut on the outer periphery of the optical filter holding frame 135. The optical filter holding frame 135 is rotatable about a rotation shaft 135g, and is configured so that the optical filter holding frame 135 rotates with the rotation of the motor 137.

Reference numerals 138 to 143 denote a brush b and an electrode a, respectively. The brush / electrode pair 138 is used as a common. It is configured to be able to detect the state up to the position of the filter.

[0009]

However, in the conventional filter switching mechanism, dedicated actuators are used for filter switching, so that cost, space, and cost are reduced.
This has led to an increase in power consumption.

The present invention has been made under such a background, and an object thereof is to realize an inexpensive, compact, and low power consumption filter switching function.

[0011]

According to the present invention, there is provided an image reading apparatus for reading an image on a transparent original via a photoelectric conversion element, wherein the scanning unit optically scans the transparent original. A switching mechanism for switching the optical filter in conjunction with the movement is provided.

Further, in the present invention, the scanning section is provided with an opening which is a part of an optical path from the light source to the photoelectric conversion element, and is provided with a projecting member. The member switches the optical filter located on the optical path by moving the filter holding unit by contacting the filter holding unit holding the plurality of optical filters when the scanning unit moves.

Further, in the present invention, the filter holding section moves so that the optical filter moves in a plane substantially perpendicular to the optical path.

In the present invention, at least a biasing force is applied to at least the filter holding portion, and after the projecting member comes into contact with the filter holding portion, the filter holding portion is moved by the biasing force. I'm moving.

In the present invention, the urging force is given by a dog spring.

In the present invention, the filter holding portion is configured to rotate.

Further, in the present invention, the filter holding portion is configured to move linearly.

Further, in the present invention, the filter holding section is connected to a rotating member to which a biasing force has been applied in advance, and a projection member provided on the scanning section abuts on the rotating member when the scanning section moves. When the rotating member rotates in contact with the rotating member, the rotating member moves linearly.

Further, in the present invention, the position at which the projection member provided on the scanning section abuts on the filter holding section or the rotating member when the scanning section is moved is outside the image reading range for reading the image of the transparent original. Is set to

Further, the present invention includes a stop member for stopping the filter holding section at a predetermined position.

In the present invention, the stop member is constituted by an elastic member.

Further, in the present invention, an opening is provided at a position of the scanning section facing one of the plurality of optical filters in a state where the filter holding section is stopped by the stop member, and the opening is provided. Utilizes shading correction.

In the present invention, at least one of the optical filters has a transmission characteristic in a visible light range, and at least one has a transmission characteristic outside a visible light range.

In the present invention, the switching mechanism may be configured such that an optical filter inserted into the optical path in conjunction with movement of the scanning unit in a direction in which the transparent original is taken out has a transmission characteristic in the visible light region. The optical filter is configured to be switched so as to have an optical filter.

In the present invention, the transparent original is constituted by a sleeve film on which a plurality of frames are arranged.

In the present invention, the transparent original is constituted by a mount film on which a single frame is arranged.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] First, a first embodiment will be described with reference to FIGS. FIG. 1 is a perspective view showing a main configuration of the embodiment, FIG. 2 is a cross-sectional view showing a main configuration of the embodiment, FIG. 3 is a schematic configuration diagram of a control system of the embodiment,
FIG. 4 is a block diagram showing a control circuit of the present embodiment, FIG. 5 is a diagram showing a state of connection between a carriage and a filter holding frame,
FIG. 6 is a flowchart showing a reading process according to the present embodiment, and FIG. 7 is a diagram for explaining the effect of dust, dust, and scratches on a film on a read image. The reference numerals denoting the components in these figures are such that the same components have the same reference numerals.

A carriage 1 holds a film (transparent original) 2. 3 is a light source having a wavelength characteristic from visible light to infrared light component, 4 is a mirror for changing the optical path, 5 is an imaging lens, 6 is a line sensor (photoelectric conversion element), and 7 is the carriage 1 in the scanning direction. A carriage motor 8 for driving is a carriage sensor for detecting the position of the carriage 1.

9 is an optical axis, 10 is an optical filter, 1
0a is an infrared cut filter, 10b is a visible light cut filter, 11 is a density sensor for detecting the density of the film, 1
2 is a first housing for accommodating a carriage or the like, 13 is a filter holding frame for holding an optical filter, 14 is a toggle spring,
15 is a screw, 16 is a lens barrel for holding the imaging lens 5, 17
Are guide bars for guiding the carriage 1 in the scanning direction;
8 is a second housing for housing the first housing 12, 19 is a film motor, 20 is a film sensor, 21 is a control circuit,
22 is a data input / output terminal.

The film 2 is held on the carriage 1 by any method. For example, another member (film holder) holding the film (mount film) 2 may be sandwiched in the carriage 1 by a leaf spring or the like, or may be held by a bayonet mechanism, a patchon mechanism, or the like. That is, the present invention provides a sleeve film in which a plurality of frames are continuous,
It can be applied to any mount film with only one piece.

A film (sleeve film) 2 or a film (mount film) is provided by a mechanism (not shown).
Is movable relative to the carriage 1, and the movement is controlled by a film driving motor 19 and a film sensor 20.

A guide bar 17 fixed by the first housing 12 or the second housing 18 is fitted to the carriage 1, and a rotation stopper 1 a formed integrally with the carriage 1 is provided on the first housing 12 and the first housing 12. By being sandwiched between the second housings 18, the degree of freedom of rotation around the guide bar 17 is eliminated. As a result, the carriage 1 is accurately guided in the scanning direction. Note that another guide bar may be provided as a rotation stop.

The carriage 1 is driven by a carriage motor 7. This is realized by a so-called screw feed mechanism or the like, in which a gear is provided on the output shaft of the carriage motor 7 or a screw provided on the carriage 1 side is connected to a screw rod to feed the screw. Also, the carriage 1 has
A connecting boss 1b for transmitting the moving force to the film holding frame 13 is integrally formed below the left and right ends of the opening 1d for reading a film image. The opening 1c for shading correction is provided on the left and right of the reading opening 1d.
Is also formed.

The light source 3 is fixedly attached to the second housing 18, and the light from the light source 3 passes through the film 2,
Opening 1 d of carriage 1, opening 1 of first housing 12
The light is guided to the line sensor 6 via the optical filter 10, the mirror 4, and the imaging lens 5, and is photoelectrically converted by the line sensor 6. In the present embodiment, the optical path is changed only once by the mirror 4.
It is not necessary to change it at all.

The optical filter 10 includes a filter holding frame 13.
Is held by As the holding method, it is conceivable to perform caulking by heat or press by a press ring. Among the optical character filters 10, the infrared cut filter 10a is arranged on the left side of FIG. 1, and the visible light cut filter 10b is arranged on the right side. Further, a boss 12a is formed integrally with the first housing 12 as shown in FIG. 1 and is fitted into a rotation hole 13a of the filter holding frame 13 to rotatably support the filter holding frame 13. I have.

Further, as shown in FIG. 2, the filter holding frame 13 is arranged so as to be sandwiched by the first housing 12, and the projection 13d of the filter holding frame 13
Is arranged so as to enter the groove 12f of the housing 12, the degree of freedom in the optical axis direction is eliminated, and the boss 12a has a degree of freedom only around the axis. In other words, the filter holding frame 13 (optical filter 10) is regulated so as to move in a plane substantially perpendicular to the optical path. Here, a screw 15a is used to prevent the filter frame 13 from coming off the boss 12a. Other examples of the stopper include a washer and caulking.

The filter holding frame 13 has an opening 13c and a boss 13b formed integrally therewith. One of the loops of the toggle spring 14 is fitted into the boss 13b, and the other loop of the toggle spring 14 is fastened to the boss 12e of the first housing 12 through the opening 13c of the filter holding frame 13. Screw 15b.

The toggle spring 14 is provided with a boss 13b and a screw 15b (boss 12e) so that the elastic force is charged to the maximum in substantially the middle of the rotation range of the filter holding frame 13.
The position is determined. That is, the toggle spring 14
When the filter holding frame 13 is located on the eject side (right side: film feeding side) of FIG. 1 from the center of rotation, a clockwise repulsive force is generated and the opposite side (left side: film feeding) Side), it is mounted in such a way that a counterclockwise repulsive force is generated.

As the toggle spring 14, either a torsion coil spring 14a or a tension spring 14b may be used. The first housing 12 is provided with a stopper 12c so that the filter holding frame 13 is positioned at a predetermined position after being rotated by the toggle spring 14.
Is provided. As the stopper 12c, a cushioning material is used to reduce impact noise and vibration of the filter holding frame 13 (optical filter 10). As this buffer, a component having high elasticity such as rubber or a spring is used. When the filter holding frame 13 is positioned by the stopper 12c, the optical filter 10 on the filter holding frame 13 is located outside the reading range for reading the image of the film 2.

In this manner, the optical filter switching mechanism having the rotationally biased force is formed on both sides around the axis of the rotary boss 12a.

Next, the carriage 1 and the filter holding frame 13
The interlocking with will be described.

As described above, two connecting bosses 1b for connecting to the filter holding frame 13 are provided on the carriage 1.
It is formed integrally. Also, this connecting boss 1b is
An escape groove 12b is formed in the first housing 12 so as not to interfere with the housing 12. The escape groove 12b is provided with an opening 12bb only at a portion connected to the filter frame 13, and the connection boss 1b pushes the filter holding frame 13 in the scanning direction at the position of the opening 12bb.

FIG. 5 shows this state. FIG.
3A shows the case where the carriage 1 is closest to the eject side, and shows a state where the infrared cut filter 10a is arranged on the optical path. When the carriage 1 is moved from the state shown in FIG. 5A in the direction opposite to the ejecting side (the direction in which the film is fed: leftward in FIG. 5), the connecting boss 1b comes into contact with the filter holding frame 13 at the center of rotation. Then, the filter holding frame 13 is rotated counterclockwise.

FIG. 5B shows the filter holding frame 13.
Shows a state in which it rotates counterclockwise and is positioned at the center of rotation. At this time, the elastic force of the toggle spring 14 is charged most. In addition, when the filter holding frame 13 is located at the center of rotation, that is, at the moment when the connecting boss 1b contacts the filter holding frame 13, both the infrared cut filter 10a and the visible light cut filter 10b are used for image reading. , Is outside the image reading range.

When the carriage 1 is further moved in the retraction direction than the center of rotation, the filter holding frame 13 rotates counterclockwise by obtaining a rotational force by the urging force of the toggle spring 14 and rotates the first housing 12. And stops at the left stopper 12c. FIG. 5C shows this state. At this time, the visible light cut filter 10b and the shading correction opening 1c are arranged on the optical axis.

Therefore, in the state of FIG. 5C, for example,
In this state, when the film motor 19 is driven to make a state where there is no film on the optical axis (a so-called plain state), it becomes possible to perform shading correction for light in the infrared region. Further, by moving the carriage 1 in the film feeding direction (rightward in FIG. 5) from the state shown in FIG. 5C, the film image can be read with light in the visible light range.

FIG. 5D shows a state where the carriage 1 is moved rightward from the state shown in FIG. 5C until the optical axis is located at the left end of the film. When the carriage 1 is further moved to the right from the state shown in FIG.
b comes into contact with the filter holding frame 13 and the filter holding frame 13
Turn clockwise. When the carriage 1 is moved to the right until the filter holding frame 13 gets over the center of rotation, the filter holding frame 13 obtains a rotational force by the biasing force of the toggle spring 14 and rotates clockwise as described above.
It is stopped by hitting the right stopper 12c of the first housing 12.

FIG. 5E shows this state. At this time,
The infrared cut filter 10a and the left shading opening 1c are arranged on the optical axis. Therefore, for example, when the film motor 19 is driven from this state to make the optical axis have no film (so-called transparent), it is possible to perform shading correction for light in the visible light region. By arranging a mechanism for ejecting the film holder or the like in this state, the infrared cut filter 10a can always cover the optical axis at the end of image capture. As a result, it is possible to immediately capture a normally used visible light image without performing an image capture using infrared light as described below.

As described above, in this embodiment, after the connecting boss 1b comes into contact with the filter holding frame 13, the filter holding frame 13 is rotated by the urging force of the dog spring 14, and
The fixing position is determined by the stopper 12c. The position where the connecting boss 1b abuts on the filter holding frame 13 is set outside the reading range in which the line sensor 6 reads the image on the film 2. This is because the filter holding frame 13 abuts on the carriage 1 to apply an extra external force, so that the feeding accuracy of the carriage 1 is not adversely affected, and the optical filter 10 is switched during image reading. This is to prevent the image from being disturbed.

The light source 3, line sensor 6, carriage motor 7, carriage sensor 8, density sensor 11, film motor 19, film sensor 20, and input / output terminal 22 among the above-mentioned mechanical parts are connected to the control circuit 21 and the electric circuit. Connected. Further, as shown in FIG. 4, the control circuit 21 includes a carriage sensor control circuit 21a, a density sensor control circuit 21b, a film sensor control circuit 21c, a motor control circuit 21d, a film motor control circuit 21e, and an image coasting processing circuit 21f. , Light source control circuit 21g, line sensor control circuit 21h, film density detection circuit 21i, motor drive speed determination circuit 21j, and image coasting information storage circuit 2
1k.

Using the mechanism and circuit structure described above, dust, dust, and scratches adhering to the illumination optical system, the projection optical system, or the film are detected, and the read image of the film 2 is corrected based on the detected information. I do. Before describing the image reading processing based on the flowchart of FIG. 6, a method of detecting the above-described dust, dust, and the like by image processing will be described.

FIGS. 7A and 7B schematically show the effects of the above-mentioned dust and dirt on image data and output images. FIG. 7A shows the case of a reversal film.
FIG. 7B corresponds to the case of a negative film.

As shown in FIG. 7, when a film original is read by a film scanner irrespective of whether the film is a reversal film or a negative film, the above-mentioned dust and dirt appear as black dots on the image signal. As a result, FIG.
In the case of a reversal film, when the above-described image signal is directly subjected to image processing such as gamma correction and output to an output device such as a printer, the above-described dust or scratch portion appears as a black point as it is. .

On the other hand, in the case of a negative film, as shown in FIG. 7B, an image signal read by a film scanner is subtracted from an image signal read at a full level, so that a negative image is converted to a positive image. Since the conversion is performed, the above-described dust and dust portions appear as white bright spots in the output image.

Therefore, paying attention to the transmittance characteristic of the film with respect to infrared light, it is detected by infrared light that transmits only dust and dust that cause the above-described image quality deterioration, and read based on the detected dust information. By correcting the manuscript data, image information excluding dust and greetings is obtained.

Next, a description will be given, with reference to the flowchart of FIG. 6, of a film document reading process in which the influence of dust, greetings and scratches is eliminated.

In step S1, an input / output terminal 2
2, a film reading command is input, and the light source 3 is turned on by the light source control circuit 21g. In step S2,
The position of the film 2 is detected by a film sensor control circuit 21c.
1 is transmitted. Then, in order to make the film 2 stand by at a position off the optical axis, the film motor control enclosure 21e
Drives the film motor 19.

In step S3, the position of the carriage 1 is determined by the carriage sensor 8 and the carriage sensor control circuit 21a.
, And the detected information is transmitted to the film scanner control circuit 21. Then, the carriage 1 is moved in the feeding direction (the right direction in FIGS. 1 and 5), and the carriage motor 7 is operated by the motor control circuit 21d so that the left shading opening 1c and the infrared cut filter 10a are arranged on the optical axis. Drive.

In step S4, shading correction is performed on light in the visible light range. In step S5, the carriage 1 is moved in the retraction direction (left direction in FIGS. 1 and 5), and the carriage motor 7 is driven so that the right shading opening 1c and the visible light cut filter 10b are arranged on the optical axis. . In step S6, shading correction is performed on light in the infrared region. In step S7,
The film 2 is moved by the film motor 19 so that the film 2 is positioned at the opening 1d of the carriage 1.

In step S8, the carriage 1 is moved in the feeding direction, and the carriage motor 7 is driven so that the infrared cut filter 10a is arranged on the optical axis. In step S9, the carriage 1 is moved in the retraction direction, and the carriage motor 7 is driven so that the film 2 is arranged on the optical axis. In step S10, the density of the film 2 is detected by the density sensor 11 and the film density detection circuit 21i. In step S11, the motor drive speed determination circuit 21 is operated based on the density of the film 2 detected in step S9.
The drive speed is determined by j.

In step S12, the carriage 1 is moved in the retraction direction, and the carriage motor 7 is driven so that the visible light cut filter 10b is arranged on the optical axis. In step S13, the carriage motor 7 is driven by the motor control circuit 21d at the drive speed determined in step S11.
When driven, the carriage 1 is moved in the feeding direction, and a scanning operation for obtaining image information of the film 2 by infrared light is performed. During this scan, the line sensor control circuit 21
The image information read by the line sensor 6 under the control of h is transmitted to the image information processing circuit 21f.

In step S14, the image information processing circuit 2
1f, using the image information, an area on the film 2 whose infrared light transmittance differs by a predetermined value or more from most other areas on the film 2 is detected, and the area is detected as a range of dust or dust. And the information on the range of the dust and dust is stored in the image information storage circuit 21k.

In step S15, the carriage 1 is further moved in the feeding direction, and the infrared cut filter 10a
Is driven on the optical axis to drive the carriage motor 7. In step S16, the carriage motor 7 is rotated in the opposite direction by the motor control circuit 21d at the drive speed determined in step S11, and a main scanning operation for obtaining image information of the film 2 by visible light is performed. During this main scan, the image information read by the line sensor 6 under the control of the line sensor control circuit 21h is transmitted to the image coasting information processing circuit 21f.

In step S17, after the main scan operation is completed, the light source 3 is turned off by the light source control circuit 21g.
The information on the range of dust and dust is transmitted from the image information storage circuit 21k to the image information processing circuit 21f, and the film image reading operation ends.

In step S18, the image information processing circuit 2
1f, the image information of the film 2 is corrected by visible light based on the range information of dust and dust, and is output from the output terminal 22.

In this way, the film image is read while eliminating the influence of dust, dust and the like. In this case, the optical filter 10 is switched in conjunction with the movement of the carriage 1, which is a scanning unit, without using a dedicated actuator for switching the optical filter 10 on the filter holding frame 13. This is a power consumption type optical filter switching mechanism. Further, a biasing force is applied to the filter holding frame 13 in advance by a toggle spring 14, and the connecting boss 1b of the carriage 1 is
Since the filter holding frame 13 is rotated by the biasing force of the toggle spring 14 after the contact with the filter, the power consumption can be reduced in this respect as well.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 8 is a perspective view showing a main configuration of the second embodiment of the present invention, and FIG.
Is a diagram showing a modified example thereof. 8 and 9, the same reference numerals as those in FIGS. 1 to 7 indicate the same parts. In the second embodiment, the configuration of the guide mechanism of the optical filter is different from that of the first embodiment, and the other configurations are almost the same. Therefore, the guide mechanism will be described with reference to FIGS. Detailed description of the mechanism and the like is omitted.

As shown in FIG. 8, the present embodiment is different from the first embodiment in that the filter holding frame 23 is configured to be guided in a straight line parallel to the scanning direction of the carriage 1. . Therefore, each component of the first embodiment shown in FIG. 1 has a configuration in which the first housing 12 and the filter holding frame 23 correspond to the linear guide mechanism in the present embodiment.

Specifically, the first housing 12 has a guide bar 12 g for a straight guide and a filter holding frame 23.
The rotation stop groove 12h for stopping the rotation of is added. This guide bar 12g is the first housing 12 in FIG.
Although it is constituted integrally, it may be a separate part. Further, the filter holding frame 23 is formed with two guide holes 23a for fitting to the guide bars 12g,
A projection 23b fitted into the rotation stopping groove 12h is added. Here, in consideration of the assemblability, the guide bar 12f has a two-sided cross section and the guide hole 13a.
Is partially cut away.

In FIG. 8, a tension spring 14b is used as the toggle spring 14 for urging the filter holding frame 23 in both the reciprocating directions of the linear guide. Extension spring 1
4b is fitted into a boss 23c formed integrally with the filter holding frame 23, and the other loop of the tension spring 14b is fitted into a screw 15a fastened to the boss 12a of the first housing 12. Inlaid. Tension spring 14
b is configured to extend most when the filter holding frame 23 is located at the center of the reciprocating path, whereby the filter holding frame 23 is attached to the right side on the right side of the center section of the reciprocating movement and to the left side on the left side. There will be power.

When the connecting boss 1b of the carriage 1 and the lower end 23d of the filter holding frame 23 come into contact with each other, the filter holding frame 23 is moved by the urging force of the tension spring 14b to move the filter holding frame 23 on the optical axis. Is switched.

As a modification of FIG. 8, FIG. 9 shows an example in which a torsion spring 14c is used as the toggle spring 14 and the filter holding frame 23 'is switched via a connecting member 13'.

The connecting member 13 ′ is configured similarly to the rotary reciprocating urging mechanism of the filter holding frame 13 shown in the first embodiment, and the connecting member 13 ′ comes into contact with the connecting boss 1 b of the carriage 1. Accordingly, the position of the filter holding frame 23 'is switched by being urged to rotate clockwise / counterclockwise.

An elongated hole 13e is formed in the connecting member 13 ', and the elongated hole 13e is fitted to the filter holding frame 23'.
Boss 23c. One of the loops of the torsion spring 14c is fitted into a boss 13b formed integrally with the connecting member 13 ', and the torsion spring 14c
Is fitted in a screw 15a fastened to a boss 12i of the first housing 12. Furthermore, the rotation hole 13a of the connecting member 13 'is rotatably fitted to the boss 12a of the first housing 12 via the screw 15a.

In FIG. 9, when the connecting member 13 'rotates clockwise, the filter holding frame 23' moves rightward (extending direction), and when rotated counterclockwise, moves leftward (extending direction). . In this manner, the filter holding frame 23 'is caused to move linearly, and the optical filter 10 is switched.

Under such a configuration, by performing the same image reading control as in the first embodiment, the optical filter 1
The image information of the film 2 can be read in a form in which the influence of dust and dust is eliminated by appropriately switching 0, and the power consumption can be reduced with an inexpensive and compact configuration as in the first embodiment. it can.

The present invention is not limited to the above embodiment. For example, the arrangement of the toggle spring may be devised, or a plurality of toggle springs may apply different urging forces depending on the position of the optical filter holding frame. It is also possible to switch between three or more types of optical filters in conjunction with the movement of the scanning unit (carriage) by devising the shape of the filter holding frame, the position and number of connecting bosses, and adding other components. is there.

[0079]

As described above, according to the present invention,
In an image reading apparatus that reads an image on a transparent original via a photoelectric conversion element, an optical filter is switched by providing a switching mechanism that switches an optical filter in conjunction with movement of a scanning unit that optically scans the transparent original. The optical filter can be switched without using a dedicated actuator for this purpose, so that it is possible to realize an inexpensive, compact, and low power consumption filter switching function.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main configuration of a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a main configuration of the first embodiment of the present invention.

FIG. 3 is a schematic configuration diagram of a control system according to the first embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a control circuit according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a state of connection between a carriage and a filter holding frame according to the first embodiment of the present invention.

FIG. 6 is a flowchart illustrating an image reading process according to the first embodiment of the present invention.

FIG. 7 is a diagram for explaining an effect of dust and dust on a film on a read image.

FIG. 8 is an oblique parent view showing a main configuration of a second embodiment of the present invention.

FIG. 9 is a perspective view showing a modification of the second embodiment of the present invention.

FIG. 10 is a diagram showing a conventional optical filter switching mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Carriage, 1b ... Connecting boss 2 ... Film, 3 ... Light source, 5 ... Imaging lens, 6 ... Line sensor 7 ... Carriage motor, 8 ... Carriage sensor, 9 ... Optical axis, 10 ... Optical filter, 10a ... Infrared Cut filter, 10b Visible light cut filter, 11 Density sensor, 12 First housing, 12b Escape groove, 13, 23 Filter holding frame, 14 Toggle spring, 14a Torsion coil spring, 14b Tension spring , 14c: torsion spring, 14b: tension spring, 15: screw, 17: guide bar, 18: second housing, 19: film motor, 21: control circuit, 13 ': connecting member.

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 2H106 AA14 2H110 AB08 CD02 5C062 AB03 AB17 AB32 AD01 AD06 BA01 5C072 AA01 BA01 BA06 CA02 DA09 DA21 EA05 FB12 RA04 VA03

Claims (16)

[Claims] 1. An image reading apparatus for reading an image on a transparent original via a photoelectric conversion element, comprising a switching mechanism for switching an optical filter in conjunction with movement of a scanning unit for optically scanning the transparent original. An image reading apparatus characterized by the above-mentioned. 2. The scanning unit according to claim 1, wherein the scanning unit is provided with an opening serving as a part of an optical path from the light source to the photoelectric conversion element, and a projection member is provided. 2. The optical filter according to claim 1, wherein when the scanning unit moves, the optical filter located on the optical path is switched by contacting the filter holding unit holding the plurality of optical filters and moving the filter holding unit. Image reading device. 3. The image reading apparatus according to claim 2, wherein the filter holding unit moves so that the optical filter moves in a plane substantially perpendicular to the optical path. 4. An urging force is applied to at least the filter holding portion in advance, and after the projection member contacts the filter holding portion, the filter holding portion is moved by the urging force. The image reading device according to claim 2 or 3, wherein 5. The image reading apparatus according to claim 4, wherein the urging force is provided by a dog spring. 6. The image reading apparatus according to claim 2, wherein the filter holding unit is configured to rotate. 7. The image reading apparatus according to claim 2, wherein the filter holding unit is configured to move linearly. 8. The filter holding section is connected to a rotating member to which a biasing force is applied in advance, and a projection member provided on the scanning section abuts on the rotating member when the scanning section moves to rotate the rotation section. 8. The image reading apparatus according to claim 7, wherein the image reading apparatus moves linearly in conjunction with the rotation of the member. 9. A position where the projection member provided on the scanning section abuts on the filter holding section or the rotating member when the scanning section is moved, is set outside an image reading range for reading an image of the transparent original. The image reading device according to claim 2, wherein: 10. A filter according to claim 2, further comprising a stop member for stopping said filter holding portion at a predetermined position.
10. The image reading device according to any one of 9 above. 11. An image reading apparatus according to claim 10, wherein said stop member is formed of an elastic member. 12. An opening is provided at a position of the scanning unit facing one of the plurality of optical filters in a state where the filter holding unit is stopped by the stop member, and shading is performed using the opening. The image reading apparatus according to claim 10, wherein the correction is performed. 13. At least one of said optical filters
2. A method according to claim 1, wherein at least one has a transmission characteristic outside the visible light range.
3. The image reading device according to any one of 2. 14. The switching mechanism, wherein the optical filter inserted into the optical path in conjunction with the movement of the scanning unit in the direction of taking out the transparent original is an optical filter having a transmission characteristic in the visible light region. 14. The image reading apparatus according to claim 13, wherein the image reading apparatus is configured to perform switching. 15. The image reading apparatus according to claim 1, wherein said transparent original is constituted by a sleeve film on which a plurality of frames are arranged. 16. The image reading apparatus according to claim 1, wherein said transparent original is constituted by a mount film on which a single frame is arranged.