JPH0261630A - Reading device - Google Patents

Abstract

PURPOSE:To excellently read a projected image by using an image rotating element so that a direction where the projected area of a transmitted original is displaced may coincide with a subscanning direction of a reading part. CONSTITUTION:A transmitted original moving part 80 for horizontally moving the transmitted original in the surface direction of the original is provided in a reading device for reading the image of the transmitted original which is enlarged and projected to the reading part 3. Moreover, the image rotating element 47 which intervenes in a projection optical path from the transmitted original to the reading part 3 and rotates the projected image is provided so that the direction where the projected area of the transmitted original is displaced by the transmitted original moving part 80 may coincide with the subscanning direction of the reading part 3. The reading part 3 scans the projected image of the transmitted original moved by the part 80. Thus, the reading scanning can be excellently performed without having the influence on an operational space and reading precision.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reading device for reading original documents in an image forming apparatus such as a copying machine, and more specifically to a reading device capable of reading photographic film.

(Prior Art) In recent years, digital copying machines have been put into practical use that can store and process image information from scanned originals as electrical signals. As it has become easier to do this, there is a growing desire to obtain copies directly from photographic film. Conventionally, copying machines have been used to obtain enlarged copies from small transparent originals such as photographic film. For example, there is one disclosed in Japanese Patent Application Laid-Open No. 59-198439.

This system additionally includes a projector, a reflecting mirror, etc. The projector enlarges and projects the film image from the side, the reflecting mirror reflects it onto the document table, and the projected image is read by a scanning optical system. That's how it is.

[Problem to be solved by the invention]

In the conventional example described above, a wide space is required for the optical path to enlarge and project the film image, and in particular, a large reflective mirror is required to reflect the enlarged image, resulting in an increase in the size of the entire device. was inviting. Therefore, in order to prevent this, instead of enlarging and projecting the entire image onto the document table, the film is moved and the reading section is kept stationary, thereby shifting the projection area relative to the reading section and scanning the entire projected image. A possible configuration is possible.

By the way, such a configuration requires a mechanism to move the film, but if it is a slide film that fits one film at a time in a mount, it can be moved relatively easily, but it will take several frames. In the case of long film pieces cut into individual pieces, it is not easy to set the film pieces.

For this reason, it is conceivable to move the film piece while it is housed in a dedicated holder. In order to make it easy to select the desired frame, it is preferable to use a long holder like the film piece.In that case, the problem is the direction of movement of the holder. .

In other words, a film piece, that is, a holder is moved in a direction corresponding to the sub-scanning direction with respect to a reading unit in which CCDs and the like are arranged in a line in the main-scanning direction. When applied to a projector with
It is necessary to move the holder vertically. This is not preferable because the operability of the moving mechanism is less accurate than in the horizontal direction, and this also affects the accuracy of reading. Furthermore, if the longitudinal direction of the holder is made vertical, a space is required above and below the projector for retracting the holder, resulting in a problem that the working space is narrowed.

The present invention has been made in view of such circumstances, and provides a reading device configured to move the holder, that is, the film, so that it can be read and scanned well in the reading section without affecting the work space and reading accuracy. For the purpose of providing.

[Means to solve the problem]

A reading device according to the present invention reads an image of a transparent original that is enlarged and projected onto a reading unit, and includes a transparent original moving unit that horizontally moves the transparent original in a surface direction of the transparent original; An image rotation element is provided in the projection optical path from the transparent original to the reading unit and rotates the projected image so that the direction in which the projection area of the transparent original is displaced by the moving unit is the sub-scanning direction of the reading unit. The reading unit is characterized in that the reading unit is configured to move the transparent original by the transparent original moving unit and scan the projected image.

[Effect]

The transparent original is moved horizontally in the direction of its surface by the transparent original moving section, and in this case, the direction in which the projection area of the transparent original is displaced by the image rotation element is made to coincide with the sub-scanning direction of the reading section. As a result, the projection area of the transparent original is shifted in the sub-scanning direction in the reading section, and the entire image is scanned.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on drawings showing embodiments thereof. FIG. 1 is a perspective view showing the internal structure of a reading device main body in a reading device according to the present invention (hereinafter referred to as the device of the present invention). The reading device main body 1 has a document table glass 2 on its upper surface, and a pair of rails 5a and 5b are disposed on the inner bottom facing each other with the longitudinal direction thereof being the width direction of the reading device main body 1. , Sb, a rectangular parallelepiped-shaped reading head 3 whose longitudinal direction is orthogonal to the extending direction of these is placed in a straddling state. The reading head section 3 has a plurality of solid-state imaging elements (CCOs) inside thereof, with its entrance side facing upward and a lower output side, as shown in the longitudinal cross-sectional view of FIG.
) are arranged in a - column and facing a reading sensor 33 of °ζ, for example, a reading lens 32 made of a convergent rod lens, a light source 31, etc. are provided. When reading a normal original, that is, an opaque original, the light source 31 is turned on, and the reflected light image of the opaque original placed on the original platen 2 is reflected by the reading lens 32. The reading sensor 33 main-scans the document, and the pulleys 4a and 4b provided on the rails 5a and 5b to be rotationally driven by the motor 4C, respectively, and the pulleys 4a and 4b that are attached to these The reading head section 3 is moved on the rails 5a, 5b by the suspended wires 7a, 7b in the width direction of the reading device main body l, that is, in the left-right direction, thereby performing sub-scanning of the document.

FIG. 2 is a longitudinal cross-sectional view from the front side showing how the reading device main body 1 is equipped with a projector, a mirror, etc. when enlarging and reading a small transparent original such as a photographic film according to the main part of the present invention. . First, the device of the present invention is as described above.
Instead of projecting the entire image of one frame of the film to be read on the document table in an enlarged manner and scanning the projected image by moving the reading section as in the case of opaque originals, the reading section The entire image is read and scanned by keeping the film stationary and moving the enlarged film to change the projection area for the reading unit, and the projector is equipped with a film movement mechanism for this purpose. Of course, the movement of the film and the signal processing of the reading section are performed in synchronization.

The projector 6 is arranged substantially horizontally at a position higher than the upper surface of the right side edge of the reading device main body 1, and its projected light is directed to a mirror 9, which will be described later, provided on the left side of the document platen glass 2. irradiated. The projector 6 is attached to the reader main body 1 on a slide rail 54 mounted on the right side of the reader main body 1 with its length direction facing the depth of the reader main body 1, as shown in the right side view of FIG. This is achieved by pivoting the center of gravity of the lower part of the projector 6 by a shaft 53 that is supported in the depth direction of the reader main body l on the upper part of the guide member 55 that slides in the depth direction. It is rotatable around a shaft 53. A strike collar 52 is disposed between the rear end of the projector 6 and the lower part of the guide member 55, and is formed by connecting two members of approximately the same size in a bendable manner at the intermediate portion thereof. As shown in FIG. 3, by extending each member of the stopper 52, the projector 6 is held in a state in which the light emitting part is directed horizontally and the film can be projected and moved. The projector 6 is rotated 90 degrees around the shaft 53 and held in a vertical state with the light emitting section facing directly upward, and as shown in FIG. 4, the slide rail 5
4 allows the projector 6 to be retracted together with the guide member 55 to the rear side of the reading device main body l, and as a result, the operation of placing the original on the original platen glass 2 and the operation of the operator during normal reading is hindered. Never. That is, the slide rail 54 is provided to retract the projector 6, and when projecting a film, the projector 6 is fixed at a predetermined position approximately in the middle of the reader main body 1 in the depth direction.

The projector 6 is equipped with a light source 40 on the rear side (right side in FIG. 2), and includes condenser lenses 42a, 42b, cylindrical lens 4 in order from the light source 4o side to the front.
3.44, film holder 70 for holding the film to be projected. A projection lens 46 and an image rotation prism 47 as the image rotation element are arranged, and a reflecting mirror 41 and a cooling fan 50 are respectively arranged behind the light source 4o.

The film holder 70 is designed to hold long pieces of film that are usually cut into lengths of several frames for storage, and are both transparent as shown in the external perspective view of FIG. Thin plate-shaped holding plate 70a and mounting plate 70 made of material
The one side edges of b are hinged together so that they can be opened and closed tightly, and the mounting plate 70b has a recess 71 that is approximately equal in thickness and width to the film for placing and positioning the film. and a plurality of dowels 72 are formed, and the holding plate 70a has a plurality of protrusions 73 that are fitted into the dowels 72 and linear patterns 74 and 74 for focusing by AP (autofocus), which will be described later. They are formed near both longitudinal ends of the presser plate 70a, with the longitudinal direction thereof set as the width direction of the presser plate 70a. In other words, the film piece is placed on the mounting plate 7.
It is placed in the recess 71 of 0b, and the holding plate 70a and the placing plate 7
It is held in a sandwiched state by bringing it into close contact with 0b.

This suppresses warping of the film, provides uniform image quality when projected, and facilitates handling by the operator.

The film holder 70 is incorporated into the projector 6 so as to be movable in the horizontal direction, that is, in the direction orthogonal to the plane of the paper in FIG. FIG. 6 is a longitudinal cross-sectional view of the film scanning section, which is the transmission document moving section that drives the projector 6, viewed from the front side of the projector 6, that is, from the projection lens 46 side. Film scanning section 8
o is provided with a flat, vertically elongated guide hole 85 through which the film holder 70 is inserted, with the width direction of the film surface as the vertical direction, passing through the projector 6 in the left-right direction; Film holder guides 84 are provided at the upper and lower parts to guide insertion of the film holder 70.
are formed at four locations, and a plurality of free rollers 81 are provided between the upper and lower portions of these rollers to support the film holder 7o in a sandwiched state from above and below. A drive roller 82 rotated by a motor 83 is provided between the free rollers 81 on the lower side, and the drive roller 82 is retracted when the film holder 7o is inserted or removed. It is designed to come into pressure contact with the With this configuration, the film holder 70 is moved in the direction of the arrow by the rotation of the drive roller 82 to scan the film image and also to select other frames on the same film. It is also possible to return the film holder 70 in the opposite direction by rotating the motor 83 in the opposite direction, thereby making it possible to cope with multiple scans of full-color images.
Since the film holder 70 holding the film is scanned by moving the film holder 70 in the horizontal direction with their longitudinal directions aligned, highly accurate and stable scanning can be performed without uneven scanning.

The projection lens 46 of the projector 6 is reciprocated in the longitudinal direction of the optical axis by a motor 45, thereby focusing the projected light image.

On the left side of the document platen glass 2 on the upper surface of the reading device main body 1, there is a long side having a depth approximately equal to the depth of the platen glass 2.
A rectangular film reading opening 8 whose short side in the width direction is slightly wider than the width of the reading lens 32 in the sub-scanning direction is formed parallel to the document table glass 2. A Fresnel lens 10 having a screen surface on the lower surface is attached to the lens to seal it. Further, a mirror lid 11 is attached to the opening 8, the negative side edge of which is pivotally supported in the depth direction of the reader main body 1, and can be opened to the left side of the opening 8. The mirror lid II has a mirror 9 of approximately the same shape and size as the Fresnel lens 10 attached to its lower surface, and can hold the mirror lid 11 in a state tilted at an angle of about 45 degrees to the upper right, thereby allowing light to be emitted from the projector 6. The projected light image is reflected onto the Fresnel lens 10 vertically downward. When the film is not read by this projection, the Fresnel lens 10 and the aperture 8
As with the projector 6, it does not interfere with the operator's movements during normal reading, and it is possible to place a reflecting mirror jig on the document table as in the past.
In addition to avoiding the hassle of removing the mirror,
11 is installed so that its longitudinal direction is orthogonal to the optical axis, it will not shift with respect to the optical axis, and no distortion will occur in the projected image.

The reading head section 3 is moved below the opening 8, and the reading lens 32 is placed on the screen surface of the lower surface of the Fresnel lens 10.
This position is the film reading position of the reading head section 3.The film reading position is not particularly limited to this position. However, if it is placed below the original platen glass 2, it is necessary to place a reflecting mirror jig on the original platen as in the past, which is not preferable and is not necessary in the first place. There is also a drawback that the amount of light used for reading is lost.For this reason, the above-mentioned problems can be solved by providing a dedicated opening and setting the reading position below the opening.

Now, the optical path of the projected light image by the projector 6, mirror 9, and Fresnel lens 10 configured as above will be explained.

FIGS. 7 and 8 are a plan view and a side view showing the optical path. The illumination system by the projector 6 constitutes a Koehler illumination system, and by creating an image of the light source 40 in the pupil of the projection lens 46, a filament image of the light source 40 is not generated on the screen surface on the lower surface of the Fresnel lens 10. , it is possible to utilize all the light beams directed from the light a40 toward the projection lens 4G.

First, the illumination light from the light source 40 is efficiently utilized by even the light rays traveling in the opposite direction to the film 75 being condensed by the reflecting mirror 41 and directed toward the light source 40, and guided to the condenser lenses 42a and 42b. The light beams condensed by the condenser lenses 42a and 42b are converged into a vertically long slit shape through cylindrical lenses 43 and 44 that change the aspect ratio, and are transmitted through the film 75 to the pupil of the projection lens 46. The image of the light source 40 is formed into a long and narrow image in the vertical direction. In other words, the cylindrical lenses 43 and 44 are provided so as to illuminate one frame image of the film 75 in the form of a vertically long slit over the entire length of the film 75 in the width direction in a part of the length direction. After this vertically long optical image is emitted from the projection lens 46, it is rotated by 90 degrees by the image rotation prism 47 to become a horizontally long image, magnified, reflected by the mirror 9, and reaches the Fresnel lens 10. do. The diffused beam of light is then converged approximately in parallel by the Fresnel lens IO, and an optical image of a long and thin film whose longitudinal direction coincides with the depth direction of the reader main body 1 is expanded on the lower screen surface. projected.

The reason why the film 75 is illuminated in a slit shape is as follows. In other words, in the device of the present invention, which performs scanning by keeping the reading head section 3 stationary and moving the film 75, it is not necessary to illuminate the film so as to project the entire image of one frame, and the scanning including the optical axis sensor 3
In the direction corresponding to the main scanning direction of No. 3, that is, in this embodiment, it is sufficient to illuminate only the direction perpendicular to the set film surface, and almost no width in the horizontal direction is required.

Therefore, by converging the illumination light from the light source 40 into a slit shape, the illuminance of the image on the screen surface can be made higher than the illuminance when the entire image is conventionally projected. Since the conventional illuminance that does not hinder reading can be ensured even if it is lower than the luminous intensity of the light source, the power consumption of the light source 40, that is, the illumination system, can be suppressed. In addition, in a conventional overall projected image, there is a difference in illuminance between the center and the periphery due to unevenness in the light intensity of the light source, so the reading sensor performs correction reading of the illumination light in the main scanning and sub-scanning directions respectively before projection. However, in the present invention, by reading the reading sensor stationary, the film is moved in a direction perpendicular to the optical axis while the optical axis of the illumination light is always projected onto the reading sensor. Therefore, even if the film is moved and the projection area changes, the illuminance at the middle of the film's slit-shaped projected image always corresponds to the illuminance at the center of the conventional overall projected image. There is no need to perform correction in the movement direction, that is, in the sub-scanning direction, and it is sufficient to perform correction only in the main-scanning direction. Furthermore, since the projected image is in the form of a slit, there is no need to use a mirror Fresnel lens or a large screen surface to reflect and project the image.
Not only can it be made smaller, but its installation height on the document table can also be significantly lowered. In this embodiment, a cylindrical lens is used to converge the illumination light into a slit shape, but a linear Fresnel lens may be used instead.

Now, as mentioned above, the optical image of the film 75 is projected onto the screen surface on the lower surface of the Fresnel lens 10.
In order to read an image with high precision, the projected image must be accurately focused. This can also be done by the operator himself moving the projection lens 46 in the optical axis direction while looking at the projected image, but here, the above-mentioned motor 4
The static focusing using the lens 5 will be explained.

In this focusing, the contrast is determined from the detection signal of the reading sensor 33 using the pattern 74 formed on the film holder 70, and the projection lens 46 is driven and focused based on the contrast. The pattern 74 has a coarse adjustment pattern 74a with a large pitch and a fine adjustment pattern 74b with a small pitch arranged side by side in the width direction of the film holder 70. Since the direction in which the patterns are arranged in parallel, that is, the longitudinal direction of the pattern 74 is made to match, substantially the entire pattern 74 is projected at the same time, and the projected image is read by the reading sensor 33.

This read signal is given to a CPU (not shown), and the CPU
U is MTF (Modulation Transf)
er Function) value and issues a drive signal to the motor 45 to move the projection lens 46 to the position where the value is maximized. In this case, first, the projected image of the rough adjustment pattern 74a is read, the projection lens 46 is moved relatively largely to the position where the MTF value thereof is maximized, and then the fine adjustment pattern 74b is read,
While slightly moving the projection lens 46, it is similarly set at a position where its MTF value is maximized. In other words, the fact that the MTF value is maximized means that in the plurality of solid-state image sensors arranged in a row in the reading sensor 33, the difference in brightness between adjacent elements to recognize the white and black of the pattern, that is, the contrast is maximized. This means that the image is not blurred and is accurately focused, so you can judge that it is in focus.

Focusing using such a pattern 74 is performed before reading the film image, but focusing is performed in parallel with reading the film image using a pattern 76 as shown in the perspective view of the film holder in FIG. It is also possible to do so. This pattern 76 has a plurality of lines approximately equal to the length of the film holder arranged in parallel in the width direction of the film holder.
That is, it is provided at a position above or below the film piece when the film holder is set in the projector 6. In other words, since the pattern 76 is always projected at a position closer to the front or further back on the screen surface together with the image of the film being moved, the part of the reading sensor 33 corresponding to that position is used as described above. At the same time as the focusing is performed based on the contrast, other parts of the reading sensor 33 read the original film image.

Note that the above-mentioned focusing using the 8F is performed using the reading sensor 33.
This is done using the detection signal of A.
It is also possible to provide a dedicated sensor for P and use its detection signal.The configuration thereof will be explained next. FIG. 10 is a longitudinal cross-sectional view of the front side of the reading device main body 1, showing an example of an AF sensor provided on a Fresnel lens 1O, and an AP sensor 90 is provided with a CCD of an appropriate length at the bottom thereof. Line sensor number 5 sensor S3. St are provided at positions slightly above the upper surface of the Fresnel lens 10 with their longitudinal directions aligned with the longitudinal direction of the reading sensor 33 and separated from each other by an appropriate length.
A beam splitter 91 is arranged to guide the projected light beams from the sensor S, , S2 to the respective sensors S, S2 with different optical path lengths. The beam splitter 91 has an optical path length up to the screen surface on the bottom surface of the Fresnel lens 10, that is, the surface to be focused, where LI is the optical path length up to the sensor S1, and L2 is the optical path length up to the sensor S2. < L < L
It is determined that r and -L=L-L2. In other words, each sensor SI and S2 with respect to the screen surface is
As a result, as mentioned above, the contrast output signal value of each sensor that reads the projected image of the film holder pattern, etc. If the top is not in focus, for example, the front of the screen surface (
The so-called front focus (or back focus)
In this case, the output of sensor Sz (or Sl) is higher than the output of Sl (or SZ), and when the focus is on the screen surface, the re-output values are equal. This relationship is used to perform AP.

FIG. 11 is a flowchart showing the control procedure, in which the output value of sensor S1 is 3(1) and the output value of sensor S2 is 82. First, in step SL, s, +s,
It is determined whether or not is zero, and if it is zero, that is, if it is extremely front focused or rear focused, the projection lens is reciprocated greatly so that an output value is generated (step S2 ” ).

Once the output is obtained, compare it and 3. >st,
In other words, when in the rear pin state, move toward the front pin, and s
If l<s2, that is, in the front focus state, each projection lens is moved by a predetermined amount in the rear focus direction (steps S3 to S5). As a result, s,=3. As a result, it is detected that the screen is in focus, and the measurement ends.

The AP sensor 90 is removed from the Fresnel lens 10 when reading a film image after the AP is completed, but it may be configured to be automatically installed or evacuated in conjunction with the AP operation. In addition, the sensor for AP is always provided at a position away from the Fresnel lens IO, such as between the opening 8 and the original platen glass 2, and the inclination angle of the mirror IE11 is changed and set only during AP. A configuration may also be adopted in which an optical path is formed to perform the AP operation.

Furthermore, in the focusing by the series of APs mentioned above,
The configuration uses a projected image of a pattern formed on a film holder made of a transparent material, but this is not particularly limited, except when AP is performed in parallel with reading the film image, and the projected image of the film is used. It is also possible to judge the contrast from the above, and in that case, as shown in the external perspective view of FIG. The opening of? A film holder formed by arranging 7, 77, .

Next, an example of the film image reading operation performed by the apparatus of the present invention constructed as described above will be explained. First, as shown in FIG. 2, the mirror lid 11 is opened and set at a predetermined angle, and the reading head 3 having the reading sensor 33, which has been read with correction in the main scanning direction, is placed below the opening 8. It is moved to the reading position, and the projector 6 is set to a projectable state. Then, the film holder 70 holding the film piece to be read is installed in the film scanning unit 80 of the projector 6, the light m4o is turned on, the pattern 74 of the film holder is projected onto the screen surface, and the AP operation is performed using this projected image. Focus by doing this. When the camera is in focus, the film holder 70 is moved to project the reading start position of a desired frame of the film piece, and read preparation is completed.

At this point, the vicinity of one end of the film piece in the longitudinal direction of one frame image is enlarged and projected in a slit shape, and after that, the reading signal of the reading sensor 33 is processed,
By synchronizing the movement of the film holder 70 in the horizontal direction by the motor 83 of the film scanning section 8o, that is, changing the projection area, the entire enlarged image of one frame is read.

Note that during this reading, it is not necessary to turn on the light source 31 of the reading head section 3.

〔effect〕

As described above, in the reading device according to the present invention, by moving a small transparent original such as a film, the projection area relative to the reading unit is changed, and the entire image is read. In this case, by using the image rotation element, the direction in which the projection area of the transparent original is displaced can be made to coincide with the sub-scanning direction of the reading section, so that a configuration in which the transparent original can be moved in the horizontal direction can be adopted. As a result, even a long holder containing a long piece of film can be moved with its longitudinal direction in the horizontal direction, which improves the operability of the moving mechanism compared to a configuration in which it moves vertically. Since it can move high and stably, that is, scan the image, reading accuracy is improved, and since there is no need for space for retracting the holder above and below, the work space is not narrowed and the projected image can be read well. The present invention has excellent effects such as:

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the internal structure of the main body of a reading device according to the present invention, FIG. 2 is a front vertical sectional view when a transparent original is enlarged and projected, and FIG. 3 is a right side view thereof. Fig. 4 is a right side view showing the projector in a retracted state, Fig. 5 is an external perspective view of the film holder, Fig. 6 is a vertical sectional view of the film scanning unit, and Figs. 7 and 8 are plan views showing the projection optical path. and a side view, FIG. 9 is an external perspective view showing the second embodiment of the film holder, FIG. 1O is a longitudinal cross-sectional view showing the equipped state of the AP sensor, and FIG. FIG. 12 is an external perspective view showing a third embodiment of the film holder. 1...Reading device body 3...Reading head section 6...
・Projector 9... Mirror 10... Fresnel lens 43.44... Cylindrical lens 45.
...Projection lens 47...Image rotating prism 70...Film holder...Film scanning unit patent

Claims (1)

[Claims] (1) A reading device that reads an image of a transparent original that is enlarged and projected onto a reading unit, comprising: a transparent original moving unit that moves the transparent original horizontally in a surface direction thereof; an image rotation element that is interposed in the projection optical path from the transparent original to the reading section and rotates the projected image so that the direction in which the projection area of the reading section shifts is the sub-scanning direction of the reading section; The reading device is characterized in that the transparent original is moved by the transparent original moving unit to scan the projected image.