JP2001350224A - Focus adjusting jig and focus adjusting method using the same focus adjusting jig - Google Patents

Abstract

(57) Abstract: A mechanism for transporting a photographic film or the like in the sub-scanning direction, a large number of light receiving elements extending in the main scanning direction, and a light source that forms an optical path through the photographic film to the light receiving elements. And a lens for forming an image of the photographic film on the light-receiving element, and arranging the photographic film on the photographic film transport path in order to adjust the image forming state of the photographic film on the light-receiving element. A focus adjustment jig equipped with a possible focus adjustment subject can be used for focus adjustment simply by placing it on the photographic film transport path, but more equally adjusts the focus in both the main scanning and sub-scan directions. To provide a focus adjustment jig capable of performing the following. SOLUTION: A focus adjustment jig FC in which a focus adjustment subject includes an inclined edge DE inclined in both main scanning and sub scanning directions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a focus adjusting jig for adjusting the focus of an image formed on a line sensor and a focus adjusting method using the same focus adjusting jig.
More specifically, the present invention relates to a transport mechanism for transporting a scanning document in a sub-scanning direction, a line sensor including a large number of light receiving elements extending in a main scanning direction intersecting the sub-scanning direction, and a scanning document. A light source that forms an optical path that reaches the line sensor through the light source, and a lens that can form an image of the scanning document based on the light source on the line sensor. A focus adjustment jig in which a focus adjustment subject that is arranged on the conveyance path of the scanning original and that can be imaged by the line sensor is formed in order to adjust an image forming state of the original on the line sensor, and The present invention relates to a focus adjustment method using the same focus adjustment jig.

[0002]

2. Description of the Related Art The above-described focus adjusting jig is mounted as a chart on a transport path (in a stationary state without transporting) instead of an image of a scanning document actually disposed on a transport path during a scanning operation. The line sensor of the target image reading device captures the clearly shaped edge and the like provided on the focus adjustment jig, which is useful for confirming the imaging state. Can be.

Conventionally, a thin plate-shaped jig having an edge extending in the sub-scanning direction has been used as such a focus adjusting jig. In a line sensor (generally composed of a CCD) in which pixels are arranged in a line in the main scanning direction and pixels are not arranged in the sub-scanning direction, they extend in the main scanning direction formed on a focus adjusting jig. This is because the image formation state of the edge cannot be confirmed.

The image formed on the sensor surface includes a slight blur due to aberrations in the main scanning direction and the sub-scanning direction. In the image forming apparatus, the imaging state can be checked only for the component in the main scanning direction, and the imaging state cannot be checked for the component in the sub-scanning direction. Therefore, the position adjustment and the mounting state of the lens or the line sensor of the image reading device can be performed. Has been adjusted exclusively based on the component in the main scanning direction.

[0005]

As a result, the component in the main scanning direction is accurately focused, but the component in the sub-scanning direction is less focused than the component in the main scanning direction. However, an image with an unnatural impression as a whole may be read by the image reading device via the line sensor.

[0006]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to take the above-mentioned drawbacks of the prior art focus adjusting jigs exemplified above and to place the scanning original stationary on the conveying path of the scanning original. A focus adjustment jig as a simple jig that can be used for focus adjustment alone, but that can perform focus adjustment more equally in both the main scanning direction and the sub-scanning direction. And a focus adjustment method using the same focus adjustment jig.

In order to achieve the above object, a focus adjusting jig according to the present invention has the features described in the first to sixth aspects of the present invention.

That is, in the focus adjusting jig according to the first aspect of the present invention, the focus adjusting jig has an inclined edge extending obliquely in both the main scanning direction and the sub-scanning direction. It is characterized by having.

With such a feature, the focus adjusting jig according to claim 1 of the present invention provides
An image obtained by forming such an inclined edge obliquely in both the main scanning direction and the sub-scanning direction on the line sensor at the corresponding position has blur in the main scanning direction and an image in the sub-scanning direction. Since both components of the blur are included, unlike the conventional focus adjustment jig, it is possible to confirm the image formation state on the line sensor also for the component of the blur in the sub-scanning direction. Therefore, if this focus adjusting jig is used, the position and the mounting state of the lens or the line sensor of the image reading device can be changed in addition to the imaging state of the main scanning direction component.
It can be adjusted so that the imaging state of the component in the sub-scanning direction is also good. As a result, the image in the sub-scanning direction can be read by the image reading device via the line sensor as an image having a natural impression as a whole, which is focused on the same level as the component in the main scanning direction.

[0010] The inclined edge on the focus adjusting jig is
A configuration may be made of at least two inclined edges separated from each other along the main scanning direction.

According to this structure, the two inclined edges separated from each other in the main scanning direction focus on both of the images formed on the line sensor. For the entire transport path,
Focus adjustment is possible. As a result, the direction of the line sensor with respect to the swinging direction around the axis along the sub-scanning direction (a type of “tilt” in which the main scanning direction of the line sensor is not strictly perpendicular to the optical axis) can also be correctly adjusted. It is also possible to adjust the axial direction of the lens to match the optical axis.

[0012] Further, a configuration may be provided in which aside from the inclined edge, an orthogonal edge extending at right angles to the main scanning direction is provided.

With this configuration, as a first step of focus adjustment, first, components in the main scanning direction are sufficiently focused using orthogonal edges, and then, as a second step,
By following the procedure of performing the focus adjustment on the component in the sub-scanning direction using the slanted edge within the range in which the focus on the component in the main scanning direction which has already been sufficiently adjusted does not significantly deteriorate, the main scanning direction and the sub-scanning The operation of focusing on both components in the direction with good balance can be efficiently performed.

Incidentally, the focus adjusting jig can be constituted by a metal plate having an opening having the inclined edge as one side.

According to this structure, the edge formed on the metal plate substantially reflects not only visible light but also infrared light. Therefore, the same one focus adjusting jig can be used as the focus adjusting jig for visible light. It can be used not only as a tool but also as a focus adjustment jig for infrared rays and the like. In actual photo processing operations, scanning documents on the transport path (usually,
If infrared rays transmitted through a photographic film in which a plurality of image frames are arranged in the sub-scanning direction) are captured by a line sensor, dust and flaws attached to the photographic film can be detected.

A light beam splitting mirror, which is inclined with respect to the optical path about an axis along the main scanning direction or the sub-scanning direction, is disposed on the optical path downstream of the transport path. The sensor may be configured to receive light transmitted through the light beam splitting mirror.

According to this structure, the visible light contained in the transmitted light transmitted through the scanning original in the conveying path is, for example, the first line sensor disposed on the main optical axis reflected by the light beam splitting mirror. The infrared ray included in the transmitted light can be transmitted through the light beam splitting mirror to be read by the second line sensor disposed on the sub optical axis branched from the main optical axis. In addition, the reading of the original image information carried on the scanning document and the detection of dust and flaws that may be included in the image information can be simultaneously and accurately performed (dust read using infrared rays). And the flaw pattern can be used as information for canceling information on dust and flaws included in the image information.)

The light transmitted through the light beam splitting mirror (infrared light in the above example) is shown in FIG. 1 because of the refractive index and the inclination of the glass plate having a predetermined thickness constituting the light beam splitting mirror with respect to the optical path. As illustrated in FIG. 3, one end in the sub-scanning direction within the effective diameter of the lens (point on the lens: P
A difference in optical path length occurs between a light beam passing through 1) and a light beam passing through the other end (point on the lens: P2) (L1 ≠ L2),
In addition, since the optical path length in the sub-scanning direction is different from the optical path length in the main scanning direction, a width is generated at a substantial imaging position of the component in the sub-scanning direction (f1 to f2), and the sub-scanning is performed. A phenomenon occurs in which the substantial imaging position of the component in the direction is shifted along the optical axis from the imaging position of the component in the main scanning direction (note that in FIG. 3, the difference in the optical path length is intentionally illustrated. Although a glass plate having a large thickness is illustrated, a beam splitting mirror as thin as possible is used in an actual apparatus.) Therefore, aberration occurs between the main scanning direction and the sub-scanning direction beyond the aberration of the lens itself.

However, using the focus adjusting jig of the present application,
If focus adjustment is performed not only for the main scanning direction component but also for the sub scanning direction component, for example, the focus adjustment is performed so that the main scanning direction component and the sub scanning direction component are not defocused so much. By doing so, images of dust and flaws can be obtained more accurately.

Further, in order to achieve the above object, a focus adjusting method according to the present invention has the characteristic configuration described in claim 7 of the present invention.

That is, the focus adjusting method according to claim 7 of the present invention is characterized by comprising the following steps: <1> For both the main scanning direction and the sub-scanning direction Disposing a focus adjusting jig having a slanted edge extending on a conveying path of the scanning document; and <2> the lens so that an image of the slanted edge obtained by the line sensor is sharper. Adjusting at least one of a position and an attached state of at least one of the line sensor and the line sensor.

With such a feature, in the focus adjustment method according to the sixth aspect of the present invention, the inclined edge extending obliquely in both the main scanning direction and the sub scanning direction. The image obtained by forming an image on the line sensor at the corresponding position contains components in both the main scanning direction and the sub-scanning direction at a fixed ratio. If the lens and the line sensor are adjusted so that the image of the inclined edge is obtained as sharply as possible on the line sensor, the image of the component in the sub-scanning direction as well as the imaging state of the component in the main scanning direction can be obtained. The condition will also be adjusted to be good. As a result, as for the component in the sub-scanning direction, an image with a natural impression as a whole, focused on the same level as the component in the main scanning direction,
It can be read by an image reading device via a line sensor.

Other features and advantages of the present invention include:
The description will become apparent from the description of the embodiment using the drawings.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an image printing apparatus IP employing a digital exposure method. The image printing device IP includes a film scanner 3 (an example of a photographic film image reading device) that reads a frame image of a developed photographic film 1 (hereinafter simply referred to as a film) as digital image data, and processes the acquired digital image data. Controller 7 for generating print data by performing printing, digital printing section 5 for exposing an image corresponding to a frame image to photographic paper 2 based on the print data, and developing processing section 6 for developing exposed photographic paper 2 And The photographic paper 2 developed by the development processing section 6 is discharged as a finished print through a drying process.

The film scanner 3 has, as main components, a film transport unit 9 (an example of a film transport mechanism) for transporting the film 1 (an example of a scanning original) in the sub-scanning direction, and intersects the sub-scanning direction. An image reading sensor IS (an example of a line sensor) composed of a large number of CCD light receiving elements extending in the main scanning direction and an optical path reaching the image reading sensor IS after passing through the film 1 conveyed by the film conveying unit 9. Halogen lamp 31 to be formed
a (an example of a light source) and a zoom lens unit 32a (an example of a lens) capable of forming an image of the film 1 based on the halogen lamp 31a on the image reading sensor IS. The image reading sensor IS is a visible light sensor 33a that reads an image on the film 1 (an example of a first line sensor).
And an infrared light sensor 34a (an example of a second line sensor) that reads an image based on dust and flaws on the film 1. Here, both the visible light reaching the image reading sensor IS and the infrared light reaching the infrared light sensor 34a are emitted from the halogen lamp 31a.
Further, a cross-shaped groove 9a having a basically flat bottom surface as illustrated in FIG. 4 is formed in the film transport unit 9 of the film scanner 3. An optical path slit 9 s extending in the main scanning direction is formed through the center of the cross-shaped groove 9 a of the film transport unit 9. FIG. 4 shows the lower surface of the film 1, that is, the conveying surfaces 9b, 9b for supporting the emulsion surface when scanning is performed. The bottom surface of the cross-shaped groove 9a is located at the same level as the conveying surfaces 9b, 9b. . Incidentally, these transport surfaces 9b, 9b form a film transport path (an example of a scanning original transport path) for guiding the transport direction while supporting the film 1 from below.

The halogen lamp 31a is a reflecting mirror 31b that reflects the light of the halogen lamp 31a to make it substantially parallel light.
, Infrared cut filter 31c and halogen lamp 3
An illumination optical system 31 including a dimming filter 31d for adjusting the emitted light of 1a to a desired color balance, and a mirror tunnel 31e for uniforming the color distribution and intensity distribution of light.
Built in. Also, the zoom lens unit 32
a is a cold mirror 32b (an example of a light beam splitting mirror) as an optical path splitting means for bending a part of the light beam forming the optical path, an infrared cut filter 32c, a zoom lens unit 32a and an infrared light sensor 34a. , And a glass plate 40 for shifting the focus position in the optical axis direction.

As described above, the image reading sensor IS
Is a visible light sensor 3 for detecting a visible image of the film 1
In addition to 3a, an infrared light sensor 34a for obtaining the state of flaws and dust on the film 1 as image information is provided. Therefore, the infrared cut filter 31c has a low transmittance in the infrared wavelength range of about 780 nm to about 1100 nm in principle, but the wavelength range of about 820 nm to about 890 nm to be detected by the infrared light sensor 34a. Sets the transmittance slightly higher. Light control filter 3
1d adjusts the color balance by giving a predetermined wavelength dependency to the transmittance in the visible light region on the shorter wavelength side than about 780 nm, and lowers the transmittance as a rule in the infrared range of about 790 nm to about 1000 nm. However, the detection target of the infrared light sensor 34a is about 820 nm to about 890 n.
The transmittance is set slightly higher in the wavelength range of m.

The zoom lens unit 32a has a size of the film 1 (that is, a 135 film having a screen size of about 24 × 36 mm, a 120 film having a width of 60 mm, and a film having a screen size of 45 × 60mm, 60 × 60mm, 60 × 70mm, 6
The controller 7 operates so as to change the magnification in a plurality of steps according to which of 0 × 90 mm. Specifically, the magnification is set to a low magnification group which is set in a plurality of steps near 1 × and a high magnification group of about 2 ×. The cold mirror 32b reflects visible light and bends its path by 90 degrees, while transmitting most of the infrared light to reach the infrared light sensor 34b.
The infrared cut filter 32c includes a cold mirror 32b
Some infrared light reflected by the filter is surely removed. This is different from the infrared cut filter 31c, and is approximately 82
Even in the infrared wavelength range of 0 nm to about 890 nm, the transmittance is sufficiently reduced to prevent infrared light from entering the visible light sensor 33a.

The glass plate 40 is used for the zoom lens unit 3
In conjunction with the change in magnification of 2a, the zoom lens unit 3
A driving unit (not shown) can perform an egress / retreat operation between an operation position that has entered the optical path from 2a to the infrared light sensor 34a and a non-operation position that has exited from the optical path. When the glass plate 40 is switched to the operation position, the focus position where the image of the film 1 is formed is changed to the zoom lens unit 32a.
Move in a direction away from By the way, as described above, the zoom lens unit 32a is set to a low magnification group and a high magnification group, but the zoom lens unit 32a is
The focus position is designed to accurately reach the visible light sensor 33a regardless of the switching of the magnification of 2a. However, for infrared light, the focus position slightly changes with the switching of the magnification of the zoom lens unit 32a.

That is, as shown in FIG. 2A, assuming that the position of the zoom lens unit 32a is "A", the focus position of the visible light exists at the position "B", which is the position of the zoom lens unit 32a. The magnification does not change even when the magnification is switched between the low magnification group and the high magnification group. On the other hand, when the zoom lens unit 32a is set to a low magnification, the focus position of the infrared light is a position “C”,
When a high magnification is set, the position is "D". Such a change in the focus position between the low magnification and the high magnification with respect to the infrared light is absorbed by operating the glass plate 40 in and out of the optical path for reading the film image. . For example, in the example of FIG. 2A, since the difference (Δf) between the focus positions of the low magnification and the high magnification is “0.2 mm”, the refractive index and the thickness of the glass plate 40 The focus position is set so as to move away from the zoom lens unit 32a by "0.2 mm" by switching to the operation position. Then, as shown in FIG. 2B, the light receiving surface of the infrared light sensor 34a is arranged at the focus position “D” when the glass plate 40 is in the inoperative position and the zoom lens unit 32a has a high magnification. If the configuration is such that the glass plate 40 is switched to the operation position according to the change of the zoom lens unit 32a to the low magnification,
Irrespective of the magnification switching of the zoom lens unit 32a, the focus position of the infrared light comes to the same “D”.

The visible light sensor 33a is provided with an image pickup optical system 32.
Of the light beam guided by the photoelectric conversion device, the CCD line sensors provided for the respective colors of red (R), green (G), and blue (B) are integrated on one chip. Each CCD line sensor has a large number (for example, 5000) in the main scanning direction, that is, the width direction of the film 1.
The light receiving elements are arranged, and any one of R, G, and B color filters is formed on the light receiving surface of each of the light receiving elements. The detection signal acquired by the visible light sensor 33a is subjected to processing such as amplification and A / D conversion by the visible light signal processing circuit 33b, and is output to the controller 7. The infrared light sensor 34a has the same configuration as the visible light sensor 33a, but the visible light sensor 33a is provided with three types of CCD line sensors corresponding to the R, G, and B wavelengths. On the other hand, only a CCD line sensor for infrared light is provided. Infrared light sensor 34a
Are subjected to processing such as amplification and A / D conversion in the infrared light signal processing circuit 34b and output to the controller 7.

When the frame image of the film 1 is positioned at a predetermined scanning position, the reading process of the frame image is started. The projection light image of the frame image is sequentially divided into a plurality of slit images by the film transport unit 9 in the sub-scanning direction of the film 1 so that the visible light sensor 3
3a and the infrared light sensor 34a,
The image signal is photoelectrically converted into image signals of R, G, and B color components and an image signal of an infrared component, and is sent to the controller 7 as raw digital image data. Such control of the illumination optical system 31, the imaging optical system 32, and the image reading sensor IS of the film scanner 3 is performed by the controller 7. The film scanner 3 has a function of reading print size information or the like magnetically recorded on the film by a magnetic reading head (not shown), in addition to the function of reading the image data of the film.

In this embodiment, the digital printing section 5 employs a PLZT shutter system. That is, a shutter array including a PLZT element is employed as the exposure head 5a. R, G, and R are provided to each shutter from the light source unit 5b via the optical fiber bundle 53.
Light of each color B is introduced. The shutter array extends horizontally across the photographic paper 2 in two rows along the width direction of the photographic paper 2, that is, in the transverse direction of the transport direction, and when a predetermined level of voltage is applied to each shutter, light is transmitted. State (open state), and when the application of the voltage is stopped, the state becomes a light blocking state (closed state). Corresponding to the pixels of the image exposed by each shutter, opening and closing each shutter exposes one line of image data extending in the transport width direction by one pixel in the photographic paper transport direction at a time.

Although not shown, the light source unit 5b includes a light source lamp different from that of the film scanner 3, a dimming filter for adjusting light emitted from the light source lamp to a desired color balance, and a rotary filter. Provided. The rotation filter is composed of optical filters of three colors, red (R), green (G), and blue (B), arranged in the circumferential direction of rotation. When this rotary filter is constantly rotated at a high speed at a constant speed, one of the R, G, and B optical filters alternately faces the light source. At each moment, the optical filter passes through the optical filter facing the light source. The light of the selected color is sent to the shutter array of the exposure head 5a through the optical fiber 53. Based on the image information of the image input from the film scanner 3, the controller 7 controls each pixel, that is, each shutter so that the image is properly reproduced on the photographic paper 2, and outputs the R, G, and B signals. The length of time during which the shutter opens for each exposure color is set as the exposure amount. In addition to the PLZT shutter method, a liquid crystal shutter method, a fluorescent beam method, a FOCRT method, and the like are known as a method of the digital printing unit, and can be arbitrarily selected according to an exposure specification.

The transport system of the photographic paper 2 for transporting the photographic paper 2 to the digital print section 5 and further transporting the photographic paper 2 exposed by the digital print section 5 to the development processing section 6 is shown in FIG. As shown in FIG. 1, a photographic paper supply line 8A for transporting the photographic paper 2 in a single row, an exposure transport line 8B for transporting the photographic paper 2 in two rows, and a development transport line 8C are divided into photographic paper supply lines 8A. A sorting device 4 for sorting the photographic paper 2 sequentially sent from the photographic paper supply line 8A into two rows of the exposure transport line 8B is provided between the photographic paper supply line 8A and the exposure transport line 8B.

As is clear from FIG. 1, the photographic paper supply line 8A accommodates a long photographic paper 2 in a roll form.
It comprises a group of pull-out rollers 8a for selectively drawing out the photographic paper 2 from one of the photographic paper magazines 10, and a group of pre-distribution rollers 8b for transferring the photographic paper 2 to the distribution device 4. A paper cutter 11 that cuts the photographic paper 2 pulled out from the photographic paper magazine 10 according to a print size corresponding to an area for exposing each image is provided downstream of the conveyance of the drawer rollers 8a.

The exposure transport line 8B comprises a wide driving roller 83, a right-hand pressure roller 84a and a left-hand pressure roller 84b, which can be independently pressed and released. The right row pressure roller 84a and the left row pressure roller 84b receive and hold the two cut printing papers 2 in order, and can simultaneously send the two printing papers 2 to the exposure position EP. Above and below the exposure position EP, first and second pairs of transport rollers R1 and R2 are provided, which can be switched between a press-contact state and a release state under the control of the controller 7. While the photographic paper 2 is being conveyed via the exposure position EP, the first and second conveyance roller pairs R1 and R2 are in a state where the photographic paper 2 is conveyed only by the first conveyance roller R1, the first conveyance The state is sequentially switched to a state of being transported by both the roller R1 and the second transport roller R2 and a state of being transported by only the second transport roller R2.

Next, a printing operation in the image printing apparatus IP having the above configuration will be schematically described. First, when the film 1 for producing a print is loaded into the film scanner 3, the image of each frame of the film 1 is read while being transported by the film transport unit 9. The image of the film 1 is read by reading the original image information photographed on the film 1 by the visible light sensor 33a and reading the original image information photographed on the film 1 by the infrared light sensor 34a. Other film 1
Read the image information of flaws and dust on the screen. The reason that such image information can be read by the infrared light sensor 34a is that the infrared light incident on the film 1 is not affected by the photographed image itself recorded on the film 1, If flaws and dust are present, they are scattered and reduce the amount of transmitted light, and the flaws and dust can be obtained as image information.

The visible image detected by the visible light sensor 33a and the infrared image detected by the infrared light sensor 34a are sent to a controller via a visible light signal processing 33b and an infrared light signal processing circuit 34b, respectively. 7 is input. The controller 7 sets an exposure amount for each pixel of each color of the image exposed by the exposure head 5a based on density information for each color of the visible image input from the visible light sensor 33a. At this time, if there is a flaw or dust on the film 1, the detection density of the flaw or dust existing part in the image detected by the visible light sensor 33a has changed from the original image density information. Is set, the image quality of the obtained print deteriorates due to the presence of flaws and dust. For this reason, the controller 7 identifies the position of the flaw or dust on the film 1 based on the detection information of the infrared light sensor 34a, and determines the position of the flaw or dust in the detected image information of the visible light sensor 33a. The detected density information is corrected from the density information of the surrounding images by a supplement process or the like, and the exposure amount is set based on the corrected density information. The controller 7 has:
A monitor 7M capable of displaying detected image information of the visible light sensor 33a and a console 7K capable of inputting the correction operation and the like by an operator are connected.

When the exposure amount is set for each pixel in this manner, the exposure head 5a is exposed to the set exposure amount on the photographic paper 2 which is transported along the exposure transport line 8B and passes through the exposure position EP. To expose the image. The photographic paper 2 on which the exposure processing has been completed is conveyed to the development processing section 6, where the photographic paper 2 is subjected to development processing, and after drying, is discharged as a completed print.

(Focus Adjusting Jig and Focus Adjusting Method) The zoom lens unit 32a or the line sensor (the visible light sensor 33a and the infrared light sensor 3) of the film scanner 3
4a), the image of the film 1 is more accurately formed on the visible light sensor 33a, and the image based on the dust and flaws on the film 1 is more accurately formed on the infrared light sensor 34.
A method for adjusting the image so as to form an image on a (focus adjustment method) and a focus adjustment jig FC used in the method will be described.

(Focus Adjustment Jig) As shown in FIGS. 4 and 5A, the focus adjustment jig FC has a generally cross-shaped contour in plan view. The cross-shaped contour of the focus adjusting jig FC is processed so as to exactly match the cross-shaped groove 9 a of the film transport unit 9. Therefore, as shown by the one-dot chain line in FIG. 4, if the focus adjusting jig FC is arranged on the film transport path so as to be fitted in the cross-shaped groove 9a, the focus adjusting jig FC
Are positioned very accurately with respect to the film transport unit 9.

The focus adjusting jig FC has two types of through holes formed as charts. One through-hole is a rectangular hole 20a that is linearly arranged along the first axis X of the focus adjustment jig FC. Individual rectangular holes 20
At a, an orthogonal edge PE extending in a straight line is formed. When the focus adjustment jig FC is fitted in the cross-shaped groove 9a, the orthogonal edge PE extends along the sub-scanning direction, in other words, at right angles to the main scanning direction. The other through hole is a pair of triangular holes 20b provided along the first axis X of the focus adjustment jig FC. The pair of triangular holes 20b are formed such that all sides constituting the triangle are arranged exactly symmetrically with respect to the second axis Y of the focus adjustment jig FC. One side of each of the triangular holes 20b has an inclined edge D that extends obliquely and accurately in a straight line in both the main scanning direction and the sub-scanning direction.
E. In a state where the focus adjusting jig FC is fitted in the cross-shaped groove 9a, the two inclined edges DE are exactly 30 ° inclined with respect to the main scanning direction. Further, the two inclined edges DE are located near both ends in the main scanning direction of the focus adjustment jig FC, and these positions correspond to the image plane of the film 1 conveyed in the conveyance unit 9 when the film scanner 3 operates. And two inclined edges DE
They are separated from each other in the width direction of the film 1.

When the focus adjusting jig FC is fitted in the cross-shaped groove 9a, the orthogonal edge PE and the inclined edge D
The corner at the lower end of E is configured to coincide with the level of the lower surface (that is, the image surface and the emulsion surface) of the photographic film 1 conveyed in the film conveyance unit 9 when the film scanner 3 is operated. ing. When the focus adjusting jig FC is fitted in the cross-shaped groove 9a, the slits 9s of the film transport unit 9 have all the through holes arranged in the focus adjusting jig FC, that is, rectangular holes. 20
a and a pair of triangular holes 20b are disposed substantially near the center. In other words, when the focus adjusting jig FC is fitted in the cross-shaped groove 9a, the slit 9s of the film transport unit 9 always intersects all the orthogonal edges PE and the two inclined edges DE. Have been.

(Focus Adjustment Method) Various procedures are conceivable for adjusting the positions and mounting states of the zoom lens unit 32a and the line sensor (the visible light sensor 33a and the infrared light sensor 34a) of the film scanner 3. However, here, in order to simplify the description, a method of adjusting the position and the mounting state of the zoom lens unit 32a and the infrared light sensor 34a will be described.

<1> A focus adjusting jig FC having an inclined edge DE extending obliquely in both the main scanning direction and the sub-scanning direction is fitted into the cross-shaped groove 9 a of the film transport unit 9. <2> An image of the orthogonal edge PE and the inclined edge DE obtained by the infrared light sensor 34a is displayed on the monitor 7M of the oscilloscope or the image printing device IP as a relationship between the position and the signal intensity. At this time, the corners at the lower ends of the orthogonal edge PE and the inclined edge DE are captured as a one-dimensional image. <3> First, the zoom lens unit 32a and the infrared light sensor are set so that the image of the orthogonal edge PE becomes sharper (ie, sharper), that is, the step of the signal intensity at the edge position becomes clearer. For at least one of the positions 34a, the position and / or the mounting state are adjusted.
By this operation, the component in the main scanning direction of the light beam emitted from the focus adjustment jig FC and passing through the zoom lens unit 32a and the cold mirror 32b and reaching the infrared light sensor 34a is completely focused. be able to.

<4> Next, at least one of the zoom lens unit 32a and the infrared light sensor 34a is adjusted in position and / or mounting state so that the image of the inclined edge DE becomes sharper. In the operation of “adjusting the image of the inclined edge DE so as to be sharper”, the light is emitted from the focus adjustment jig FC, passes through the zoom lens unit 32a and the cold mirror 32b, and reaches the infrared light sensor 34a. The blur of the component in the main scanning direction and the component in the sub-scanning direction of the light beam is adjusted, and the infrared light emitted from the focus adjustment jig FC passes through the zoom lens unit 32a and the cold mirror 32b. The focus is adjusted in consideration of both the main scanning direction and the sub-scanning direction components of the light beam reaching the sensor 34a. By performing each of the above steps in order, the zoom lens unit 32a and the infrared light can be adjusted so that the imaging state of the component in the sub-scanning direction is improved in addition to the imaging state of the component in the main scanning direction. The position and mounting state of the sensor 34a can be adjusted.

Furthermore, in the focus adjustment method using the above-described orthogonal edge PE or the inclined edge DE, all possible orthogonal edges PE separated from each other along the main scanning direction as much as possible and the two inclined edges DE are used. By focusing on both of them, the focus can be adjusted particularly for the entire conveyance path along the main scanning direction. As a result, each line sensor 33 in the swing direction around the axis along the sub-scanning direction
The directions of a and 34a (the direction of the main scanning direction of the line sensor, which is not strictly perpendicular to the optical axis) can be correctly adjusted, and the adjustment can be made such that the axis of the zoom lens unit 32a matches the optical axis. Becomes

If the inclined edge DE is used, the light source
Of the sub-scanning direction included in the light beam
Check the image formation state of the components on the line sensor.
The following explanation can be given as to why
It is. FIG. 5B is a perspective view of the focus adjusting jig FC.
It is an enlarged view of upper slope edge DE in (a).
Here, the light beam input from the light source through the slit 9s
The width of the region where the
In the following, the temporary on the inclined edge DE
Three imaginary points (point Q₊₁, Point Qo, and point Q_-1) To set
explain. When focus is ideally set in the sub-scanning direction
Means that only light from point Qo of these three points
Think of the distance between each of the three points as
Set. Therefore, the component in the sub scanning direction is ideally focused.
When point adjustment is being performed, one point Qo
The image is taken by the light receiving element of the sensor and the point Q _-1And Q₊₁Is
No image is captured. However, focus on components in the sub-scanning direction
If the point adjustment is slightly incomplete than the ideal,
In a slightly wider range with respect to the direction (Y direction in FIG. 5),
The edge DE is imaged. That is, the point Q₀Other
The point Q in the sub-scanning direction (Y direction in FIG. 5)₀Before
The point Q adjacent to the back_-1And Q₊₁Are imaged.
That is, the point Q_-1Or Q₊₁Is the point Q₀To the Y direction
At the same time, a position shifted in the X direction (that is, the main scanning direction)
, These points Q_-1Or Q₊₁Main scan
Direction, the image is taken by the corresponding light receiving element.
You. The blur information in the sub-scanning direction
This is reflected in the detection information of the in-sensor. The main run
As for the blur in the inspection direction, no particular explanation is required,
Omitted.

The method of adjusting the position and the mounting state of the visible light sensor 33a can be carried out in the same manner as described above for the zoom lens unit 32a and the infrared light sensor 34a. In the film scanner 3 of the image printing apparatus IP according to the present embodiment, only visible light reflected on the upper surface of the cold mirror 32b without penetrating the cold mirror 32b reaches the visible light sensor 33a. Although the focal position does not shift in the sub-scanning direction based on the time, the zoom lens unit 32a
In the case where a difference in optical path length between a light beam passing through one end side and a light beam passing through the other end side in the sub-scanning direction of the zoom lens unit 32a is considered due to the optical characteristics of
The components in the sub-scanning direction may be adjusted in the same manner as described above using the focus adjustment jig FC.

Further, as described above, since the focus adjusting jig FC is formed of a metal plate that does not transmit visible infrared light except for the through-holes, the same focus adjusting jig is used for the visible light. Not only as a focus adjustment jig for infrared light but also as a focus adjustment jig for infrared rays.

[Other Embodiments] <1> In the focus adjustment method of the above embodiment, the image of the orthogonal edge PE is exclusively used for adjustment in the main scanning direction component, and the image of the inclined edge DE is exclusively used in the sub scanning direction. Used as an adjustment for components. However, the inclined edge DE
Already contains components in both the main scanning direction and the sub-scanning direction. Therefore, the orthogonal edge PE is omitted, and as a focus adjustment jig having only the inclined edge DE,
By performing the focus adjustment so that the inclined edge DE becomes a sharp image at least, it is possible to simultaneously perform the adjustment regarding the main scanning direction component and the adjustment regarding the sub-scanning direction component.

<2> The ratio of the main scanning direction component and the sub-scanning direction component contained in the image obtained by forming the inclined edge DE on the line sensor at the corresponding position is determined by the inclination edge DE
It is determined by the inclination angle of. Therefore, if a focus adjustment jig in which inclined edges of various inclination angles are arranged along the main scanning direction, weighting between the focus adjustment operation for the sub-scanning direction component and the focus adjustment operation for the main scanning direction component can be freely performed. Can be changed. Alternatively, several types of focus adjustment jigs having different inclination angles of the inclined edges may be prepared and used appropriately.

<3> If it is a dedicated visible light focus adjustment jig for the visible light sensor 33a for reading the image of the film 1, the image of the inclined edge is made of silver halide on a transparent material such as a constituent material of a photographic film. It may be formed by the above method. Since the image of the inclined edge formed of silver salt or the like easily transmits infrared light, a metal film having a predetermined thickness is deposited on a photographic film to be used as a focus adjusting jig for infrared light. What is necessary is just to form a film.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an image printing apparatus.

FIG. 2 is a schematic view showing the operation of a light transmitting body for changing a focus position.

FIG. 3 is a schematic diagram illustrating a difference in optical path length in a sub-scanning direction caused by a cold mirror.

FIG. 4 is a perspective view showing a focus adjusting jig and a film transport path according to the present invention.

FIG. 5 is a plan view of a focus adjusting jig according to the present invention.

[Explanation of symbols]

 Reference Signs List 1 photographic film 9 film transport unit 9a cross-shaped groove 9s slit 31a light source 32a zoom lens unit (lens) 32b optical path branching means (cold mirror) 33a sensor for visible light 34a sensor for infrared light 40 glass plate (transparent for changing focus position) Optical body) FC Focusing jig DE Orthogonal edge PE Inclined edge

Claims (7)

[Claims] A transport mechanism configured to transport a scanning document in a sub-scanning direction; a line sensor including a plurality of light-receiving elements extending in a main scanning direction intersecting with the sub-scanning direction; An image reading apparatus comprising: a light source forming an optical path reaching a line sensor; and a lens capable of forming an image of the scanning document based on the light source on the line sensor. A focus adjustment jig in which a focus adjustment subject that is arranged on a conveying path of the scanning original and is capable of being imaged by the line sensor is formed in order to adjust an image forming state, wherein the focus adjustment jig is provided. A focus adjusting jig, wherein a subject has an inclined edge extending obliquely in both the main scanning direction and the sub-scanning direction. 2. The focus adjusting jig according to claim 1, wherein the inclined edge extends linearly. 3. The focus adjusting jig according to claim 1, wherein the inclined edge is composed of at least two inclined edges separated from each other along the main scanning direction. 4. The focus adjusting jig according to claim 1, further comprising an orthogonal edge extending perpendicular to the main scanning direction. 5. The focus adjustment jig according to claim 1, wherein the jig is made of a metal plate having an opening having the inclined edge as one side. 6. A light beam splitting mirror, which is tilted around an axis along the main scanning direction or the sub-scanning direction with respect to the optical path, is disposed on the optical path downstream of the transport path, 6. The line sensor according to claim 1, wherein the line sensor receives light transmitted through the light beam splitting mirror.
The jig for focus adjustment according to the paragraph. 7. A transport mechanism for transporting a scanning original in a sub-scanning direction, a line sensor including a plurality of light receiving elements extending in a main scanning direction intersecting with the sub-scanning direction, and the scanning original passing through the scanning original. An image reading apparatus comprising: a light source forming an optical path reaching a line sensor; and a lens capable of forming an image of the scanning document based on the light source on the line sensor. The focus adjusting method for improving the above-mentioned image forming state, the focus adjusting method includes the following steps: <1> forming an inclined edge that extends obliquely in both the main scanning direction and the sub-scanning direction. Having the focus adjusting jig disposed on the conveying path of the scanning original; and <2> the image of the inclined edge obtained by the line sensor is more As a Sharp, for at least one of the line sensor and the lens, adjusting at least one of the position and the mounting state.