JPH118737A - Image input device, image input controller and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image input device capable of fetching images by an optimum resolution from a large reflection original to a small transmission original. SOLUTION: An original 21 is illuminated by a line light source 4 or 12 and the image is formed at a CCD line sensor 6 through a zoom lens 5. The magnification of the zoom lens 5 can be continuously changed and the feed pitch of a carriage 3 can be changed. By changing the magnification of the zoom lens 5 and changing the feed pitch of the carriage 3, the images of the original 21 from a large size to a small size are fetched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image input device, an image input control device, and a recording medium for capturing an original as an image signal. The present invention relates to an image input device, an image input control device, and a recording medium for capturing an image two-dimensionally by a scanning mechanism.

[0002]

2. Description of the Related Art FIG. 8 shows an example of a conventional image input apparatus. In the figure, a document table glass surface 52 on which a document 50 is placed is provided on the upper surface of the image input device 51. A carriage 53 is provided inside the image input device 51 so as to be movable in parallel with the platen glass surface 52, and scans the document 50 in the direction of the arrow in the drawing. The carriage 53 includes a line light source 54 for irradiating the original 50 with light, and a lens optical system 5 for reducing and projecting the reflected light of the irradiated original 50.
5 and C provided on the image plane of the lens optical system 55
It has a CD line sensor 56.

In the image input device 51, when the original 50 is a reflective original, the original 50 is irradiated with light emitted from a line light source 54, and the reflected light is transmitted to a CCD by a lens optical system 55.
An image is formed on the line sensor 56. The CCD line sensor 56 is electronically scanned in the main scanning direction. Also, manuscript 5
The carriage 53 is mechanically moved with respect to 0, and scanning is performed in the sub-scanning direction. As a result, an image is captured two-dimensionally.

When the original 50 is a transparent original, a transmission illumination unit 60 is mounted on an upper portion of a main body 57 of the image input device 51. The line light source 6 provided in the unit 60
1 is moved in parallel with the platen glass surface 52 in synchronization with the carriage 53 in the same direction.

There are various sizes of originals, from small 35 mm film to large A4 size.
Size, 8 inch × 10 inch size film, etc. The types of originals include printed matter, photographic paper, film, and the like, and the contents include images and character originals. There are various originals of different sizes and types depending on the combination.

[0006] In general, up to A4 size for printed reflective originals,
The standard size of photographic film is up to 4 × 5 inches. And even with a flatbed scanner, A
Documents of up to four sizes can be input.

The number of pixels in a CCD line sensor is limited, and generally available CCD line sensors have about 5,000 pixels per line. CCD line sensors of this class and above have a low performance to cost ratio and cannot be used in inexpensive devices. The pixel size of this CCD line sensor is 7-8μ
m, so that an A4 size image can be captured at a resolution of 600 dpi using an optical system having a practical level of performance.

On the other hand, in consideration of printing, the resolution at the time of inputting an image is required to be at least 300 dpi or more in the case of an A4 size print character document, and in the case of a print image document,
600 dpi is often used in practice. It is sufficient for printed matter, but for photographic paper and film, it is necessary to input at a higher resolution because of the large amount of information. In general, 1200 dp for 35 mm size film
i or more is required. Thus, in order to optimally capture various images and characters, it is necessary to change the capture resolution according to the document size.

Focusing on the capture size, if the film size is up to 4 × 5 inches, it is about 1 inch of A4 size.
Since the size becomes / 2, 1200 dpi can be achieved by using a 5000 pixel CCD line sensor. 35m
If it is exclusively for m-size film, 3500 dpi is possible. In fact, an apparatus called a film scanner achieves high-resolution capturing by limiting an original to film.

In order to solve this problem even in a flatbed scanner, conventionally, as shown in FIG. 9, a transmission unit 60 is provided with optical systems 55A and 55C independent of a main body 57.
It has been proposed to provide a carriage 53A provided with a CD line sensor 56A. In this apparatus, light from a line light source 54 in a carriage 53 of a main body 57 is irradiated onto a transparent original 50, and the transmitted light is transmitted to a high-resolution lens optical system 55A and a CCD line sensor 56A. Capture with resolution.

Also, as shown in FIG.
Two lenses 55B and 55C as a projection optical system inside
It is also proposed that the CCD line sensor 56 is shared, and the lens 55B and the lens 55C are switched in accordance with the resolution to capture an image.

[0012]

However, a film scanner cannot cope with a reflection original. Conversely, the flatbed scanner can handle both reflective originals and transmissive originals, but has a problem in that transparent originals such as 35 mm film cannot be captured at a sufficiently high resolution.

In the case of the example shown in FIG.
Is about the same cost and size as the main body 57,
In the case of the example of FIG. 10, the number of lenses that can be placed inside the carriage 53 is limited to two while keeping the size of the apparatus. In addition, since the CCD line sensor 56 is shared, the distance (C
Since the lenses are physically switched in a state where the distance between the CD originals is kept constant, it is difficult to regulate the plurality of lenses by defining the magnification. Also, preparing separate lenses for each document increases the installation space,
The connection with the host also becomes cumbersome.

Although there is a technique for interpolating image data by software, interpolation to the high resolution side is to create information that is not recognized in the first place, and the image quality is higher than when optically captured at a high resolution. Obviously the inferiority.

In order to increase the number of pixels of the CCD line sensor to increase the resolution, if the pixel size is not reduced, only the size of the device is increased, and a high-performance optical system is required. Increases realism and costs.

Further, even if a plurality of optical systems 55 are provided in the carriage 53 with the current CCD line sensor,
The number is limited to two due to the size of the apparatus. Even if three or more can be provided, the adjustment becomes more and more complicated, it is difficult to improve the performance of the apparatus, and the cost is increased. Providing another optical system for the transmission unit 60 is substantially the same as preparing two devices, which results in an increase in the size of the transmission unit and a significant increase in cost.

The present invention has been made in view of such a situation, without changing the pixel size of the CCD line sensor, switching between a plurality of lenses, and using a separate optical system. It is another object of the present invention to provide a device which can capture a document at a resolution suitable for the document size and type while maintaining the device size.

[0018]

An image input apparatus according to claim 1 is a generating means for generating light for irradiating a document, and a light receiving means for receiving light from the document and scanning in a main scanning direction. Scanning means for scanning the document at a predetermined pitch in the sub-scanning direction, and optical means for optically forming light from the document on the light receiving means and continuously changing the magnification thereof. Features.

According to a fourth aspect of the present invention, there is provided an image input control device for controlling an image input device capable of continuously changing the magnification of an image from a document optically. First setting means for setting a value, a second setting means for setting a maximum optical resolution when an arbitrary value of the optical resolution of the document is not set by the first setting means, and a predetermined optical resolution And control means for controlling the image input device in accordance with the output of the first or second setting means so that is set.

According to a fifth aspect of the present invention, there is provided a recording medium, wherein a first setting step of setting an optical resolution of a document to an arbitrary value, and when an arbitrary value of the optical resolution of the document is not set in the first setting step, A second setting step of setting the maximum optical resolution; and a control step of controlling the image input device in response to the output of the first or second setting step so that a predetermined optical resolution is set. The program is recorded.

In the image input device according to the first aspect, the light from the document is optically focused on the light receiving means, and the magnification can be continuously changed. Therefore,
An original of an arbitrary size can be taken in at an arbitrary resolution, and an increase in size and cost of the apparatus can be suppressed.

In the image input control device according to the fourth aspect and the recording medium according to the fifth aspect, when the optical resolution of the document is not set to an arbitrary value, the maximum optical resolution is set. Therefore, the user can always obtain an image with the best image quality without performing any special operation.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below. In order to clarify the correspondence between each means of the invention described in the claims and the following embodiments, each means is described. When the features of the present invention are described by adding the corresponding embodiment (however, an example) in parentheses after the parentheses, the result is as follows. However, of course, this description does not mean that each means is limited to those described.

The image input device according to the first aspect of the present invention includes a generating means (for example, a line light source 4 in FIG. 1) for generating light for irradiating the original, light from the original, and scanning in the main scanning direction. Light receiving means (for example, the CCD line sensor 6 in FIG. 1), scanning means (for example, the carriage 3 in FIG. 1) for scanning the document at a predetermined pitch in the sub-scanning direction, and optically receiving light from the document to the light receiving means. An optical unit (for example, the zoom lens 5 in FIG. 1) which forms an image and whose magnification can be continuously changed is provided.

According to a fourth aspect of the present invention, there is provided an image input control apparatus for controlling an image input apparatus capable of continuously changing the magnification of an image from a document optically continuously. A first setting means (for example, step S4 in FIG. 5) for setting a value, and a second setting means for setting the maximum optical resolution when an arbitrary value of the optical resolution of the document is not set by the first setting means. Setting means (for example, step S3 in FIG. 5) and control means (for example, FIG. 5 in FIG. 5) for controlling the image input device in response to the output of the first or second setting means so that a predetermined optical resolution is set. Step S1
0, S11).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In FIG. 1, an original platen glass surface 2 on which an original 21 is placed is provided on the upper surface of a main body 9 of the image input apparatus 1. Inside the main body 9, the original platen glass surface 2 is parallel to the original platen glass surface 2. A carriage 3 that moves in the direction of the middle arrow and performs sub-scanning is provided. In the carriage 3, a line light source 4 for reflecting an original which generates light to irradiate the original 21,
The optical path of the reflected light from the mirror 8 is converted by the mirror 8 and reduced and projected.
A zoom lens 5 as an optical system whose magnification is continuously variable;
And a CCD line sensor 6 located on the image forming plane of the zoom lens 5.

In this embodiment, the CCD line sensor 6 has a pitch of 8 μm and has 5100 pixels. The carriage 3 is moved at a predetermined feed pitch by a drive unit (not shown) such as a stepping motor 10, a belt mechanism, and a ball screw mechanism.

The zoom lens 5 has a two-group configuration (lens 5A and lens 5B) shown in FIG. 2, and the positions of the lens 5A and lens 5B are changed by zoom motors 33 and 34. Thus, the projection magnification can be changed without changing the distance between the CCD line sensor 6 and the document 21. For example, lens 5
A, 5B is when placed in the position shown in FIG. 2 (a) (WIDE position), a wider range R _W of the document 21 is imaged on the end of the CCD line sensor 6 to the end, FIG. 2 (b ), A narrower range R _T is imaged from one end of the CCD line sensor 6 to the other end. The zoom lenses 5A and 5B are provided with position detecting detectors 31 and 32, respectively.

A transmission illumination unit 11 is rotatably attached to the main body 9 of the image input apparatus 1 by a hinge mechanism 7. Inside the unit 11, a line light source 12 for a transmission original is mounted on the carriage 3. It is provided so that it can move in parallel in synchronization. The transmitted illumination unit 11 may be detachable from the main body 9 or may be attached only when reading a transparent original.

Next, the operation of the image input apparatus 1 of the present invention will be described. When the power is turned on, the zoom lens 5A,
5B is located at the initial position. Next, when the user inputs a predetermined optical resolution setting, the zoom lens 5A,
5B is moved by the motors 33 and 34 to a position where the specified optical resolution is obtained from the initial position.

When the original 21 is a reflection original, the line light source 4 is turned on, and the light is irradiated on the original 21. The light reflected from the document 21 is deflected by the mirror 8 and then enters the CCD line sensor 6 via the lenses 5A and 5B. Data of one line of the document 21 is electronically main-scanned and captured. When the capture for one line is completed, the carriage 3 is mechanically moved in the sub-scanning direction, and the image for the next one line is captured. This operation is repeated, and the image is captured two-dimensionally.

If the CCD line sensor 6 can take in an 8.5 inch size document at 600 dpi, for example, the pitch in the main scanning direction at that time is 8 μm, and the pitch in the sub scanning direction is also 8 μm. Assuming that the magnification change of the zoom lens 5 can be up to M times, the optical resolution that can be set is from 600 to 600M. When the optical resolution is set to M times, the pitch in the sub-scanning direction is set to 1 / M times. This is the stepping motor 10
At a speed of 1 / M.

When the original 21 is a transparent original, the line light source 12 is turned on instead of the line light source 4, and the light is irradiated on the original 21. Then, the transmitted light from the original 21 is
The light enters the CCD line sensor 6 via the mirror 8 and the zoom lenses 5A and 5B. Then, reading is performed as in the case of the reflection original.

If the magnification is deviated due to a change in spherical surface or the like and correction is required, an image of a chart (not shown) built in the main body 9 is taken in and corrected based on this. Can be added. At the time of this correction, the focal plane can be adjusted at the same time, and by performing this adjustment, the lens focal point movement at each set magnification can be absorbed. In addition, moire and the like can be reduced.

Next, a description will be given of an example of a configuration in which such an image input device 1 is controlled by a personal computer and captured by the image input device 1.

FIG. 3 shows an example of the internal configuration of the image input apparatus 1 in such a case. The CPU 81 uses R
According to the program stored in the OM 82, various processes are executed. The RAM 83 appropriately stores programs and data necessary for the CPU 81 to execute various processes. The interface 84 includes an input unit 85
Is connected, and the user can input various commands to the CPU 81 by operating the input unit 85. The interface 84 is connected to the CCD line sensor 6, the detectors 31 and 32, and further includes a light source driving circuit 86 for driving the line light sources 4 and 12, a motor 10,
A motor drive circuit 87 for driving the motors 33 and 34 is also connected. A connection unit 88 is further connected to the interface 84. The connection unit 88 is connected to the image input device 1.
Can be connected to a personal computer 90 for controlling the computer.

FIG. 4 shows an example of the internal configuration of the personal computer 90. The CPU 91 executes various processes of the personal computer 90. The program executed by the CPU 91 is stored in the ROM 92. The RAM 93 appropriately stores programs and data necessary for the CPU 91 to execute various processes. The interface 94 is connected to an input unit 95 that is operated when the user inputs various commands, and is also connected to a display unit 96 such as a CRT or an LCD that displays a predetermined image. Hard disk 9
7, various programs and data are stored as appropriate. The connection unit 98 includes the image input device 1 and the printer 101
Is connected.

Next, referring to the flowchart of FIG.
The image input device 1 via the personal computer 90
An example of processing in a case where an image of a predetermined document is fetched is described below.

First, in step S1, the user:
By operating the input unit 95, the reading resolution Res is set. Generally, this reading resolution is defined by the performance of the printer 101 that outputs an image. Next, proceeding to step S2, the user determines whether or not to set an optical resolution (capture size). When setting an optical resolution of an arbitrary value, the process proceeds to step S4, and the user executes the setting process. This setting is performed, for example, by operating the input unit 95 to input the size (A4, B5, etc.) of the original 21,
The width of the document 21 is input as a numerical value. However, the optical resolution (capture size) Wn input in this way
Is a value equal to or less than the maximum value Wmax that can be captured by the image input device 1, as shown in FIG.

If it is determined in step S2 that the optical resolution is not set, the input of the optical resolution is not performed.
At this time, the CPU 91 sets Wmax as the capture size Wn in step S3.

Next, proceeding to step S5, the user operates the input unit 95 to instruct a preview. CPU91
When the preview command is input, the connection unit 9
8, the image input device 1 is instructed to perform a preview.
The CPU 81 of the image input device 1
When receiving this command input, the line light source 4 (or the line light source 12) is turned on via the light source driving circuit 86,
The document 21 is illuminated. Further, the CPU 81 controls the motor 10 via the motor drive circuit 87 to move the carriage 3 in the sub-scanning direction. Light from the original is taken into the CCD line sensor 6 via the zoom lens 5. In this way, the CPU 81 performs, for example, 75 dpi.
An image of the original 21 is captured at a coarse resolution of about 100 dpi.

The image data output from the CCD line sensor 6 is transferred to the personal computer 90 via the connection unit 88. C of the personal computer 90
When receiving this image data via the connection unit 98, the PU 91 outputs the image data to the display unit 96 and displays it.

Next, proceeding to step S6, the user looks at the preview image and crops the range that he / she actually wants to capture. This cropping process is performed by operating the input unit 95. When the cropping operation is performed in this manner, the CPU 91 proceeds to step S
At 7, the cropped area is detected. Then, the range is set to Wcrop.

Next, the process proceeds to step S8, and it is determined whether or not the cropping range Wcrop detected in step S7 is equal to or less than the minimum value Wmin of the capture size in the main scanning direction as shown in FIG. When the cropping range Wcrop is smaller than Wmin, such a small width cannot actually be captured.
Sets the minimum value Wmin as the capture size Wn.

If the cropping range Wcrop is larger than the minimum value Wmin, the process proceeds to step S10, where the CPU 91
Is the cropping range Wcrop detected in step S7.
Is set as the capture size Wn.

In this case, as shown in FIG. 7A, when the center of the crop region 111 is located at a position corresponding to the center of the CCD line sensor 6, the cropping range Wcrop is set as the capture size Wn. . as a result,
Images are captured such that the left and right ends of the crop region 111 correspond to the left and right ends of the CCD line sensor 6.
That is, cropping range Wcrop is taken to correspond to the length L ₁ of the CCD line sensor 6.

On the other hand, as shown in FIG.
If the center of the crop region 111 is offset from the center of the CCD line sensor 6 to the left or right from the center of the crop region 111, when the width of the end portion of the left side is assumed to be W _3, range W'crop enlarging the width of the crop region 111 from the center to a width W ₃ on the right as a cropping range, varying times are set. That is, in this case, Wn = W'crop. Therefore,
In this case, W'crop is the length L ₁ of the CCD line sensor 6.
The cropping range Wcrop actually specified corresponds to the length L ₂ of the CCD line sensor 6. CCD
An image in the range of the length L ₁ -L ₂ on the line sensor 6 becomes substantially useless image data. In order to prevent this, the user needs to set the center of the crop area 111 to the CCD line sensor 6.
The original 21 is placed on the platen glass surface 2 so that
What is necessary is just to arrange | position again on above.

In any case, in this way, the crop region 111 is captured as the image of the maximum size.

When the capture size Wn is set as described above, the process proceeds to step S11, and the CPU 91 of the personal computer 90 sets the capture size (optical resolution) so that the set capture size (optical resolution) is set. A control signal is output to the image input device 1 via the connection unit 98. Step S
9, the same applies to the case where the capture size Wn is set to the minimum value Wmin.

In the image input device 1, the CPU 81
Receives the control signal through the connection unit 88, the motor 33, 34 via the motor drive circuit 87.
To a position where the specified optical resolution can be achieved.
The zoom lenses 55A and 55B are moved.

Next, in step S12, the CPU 91 of the personal computer 90 sets the reading resolution Res set in step S1 and the optical resolution (capture size) set in step S3, step S4, step S9, or step S10. The reciprocal of Wn has a predetermined coefficient K
It is determined whether the values multiplied by are equal. That is, since the optical resolution (capture size) Wn is represented by the length of the width of the document 21, in order to make it correspond to the reading resolution Res, a reciprocal thereof may be multiplied by a predetermined coefficient K.

If the reading resolution Res is equal to K / Wn, the process proceeds to step S13, where the CPU 91 controls the image input apparatus 1 via the connection section 98 to execute a normal scan.

On the other hand, in step S12,
If it is determined that the reading resolution Res is not equal to K / Wn, the process proceeds to step S14, and it is determined whether Res is smaller than K / Wn. If Res is smaller than K / Wn, the process proceeds to step S15, and the CPU 91 causes the image input device 1 to execute the thinning scan.
If Res is equal to or larger than K / Wn, the process proceeds to step S16, and the CPU 91 instructs the image input device 1 to perform a soft interpolation scan.

The CPU 81 of the image input device 1 includes a connection unit 8
When a command for a scan, a thinning scan, or a soft interpolation scan is received via the control unit 8, the following processing is executed. That is, when a normal scan is instructed, the CPU 81 causes the image data captured by the CCD line sensor 6 to be directly output from the connection unit 88 to the personal computer 90. Similar processing is performed when a soft interpolation scan is instructed. On the other hand, when the thinning scan is instructed, the CPU 81
Performs a thinning process on predetermined pixel data among the pixel data captured by the CCD line sensor 6 and outputs only the remaining pixel data to the personal computer 90.

The personal computer 90 takes in the pixel data supplied from the image input device 1 through the connection section 98 and temporarily stores the pixel data in the RAM 93.

When the CPU 91 instructs a normal scan in step S13, in step S17,
This is read out, output to the display unit 96 and displayed. Also, when the thinning scan is instructed in step S15, since the pixel data has already been thinned, the RAM 93
Is directly output to the display unit 96 for display.

On the other hand, in step S16,
When a soft interpolation scan is commanded, the CPU 91
Generates new pixel data by interpolation processing from the pixel data stored in the RAM 93, reads out the pixel data after the completion of the interpolation processing from the RAM 93, outputs the pixel data to the display unit 96, and displays the same.

The pixel data thus captured and processed as necessary is output to the printer 101 via the connection section 98 as appropriate, and printed on paper or the like.

As described above, when the user specifies the optical resolution, the specified optical resolution is set. When not specified, the optical resolution is automatically set so as to obtain the maximum optical resolution. Control is performed. Therefore, the user can easily and reliably obtain an image of the best image quality.

[0061]

As described above, according to the image input apparatus of the first aspect, the light from the document is optically focused on the light receiving means, and the magnification can be continuously changed. Therefore, it is possible to capture an image of a reflection document or a transmission document of an arbitrary size at an arbitrary resolution, and it is possible to suppress an increase in size and cost of the apparatus.

According to the image input control device of the fourth aspect and the recording medium of the fifth aspect, when the optical resolution is not set to an arbitrary value, the maximum optical resolution is set. Thus, the user can easily and reliably obtain a high-quality image without special operation.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of an image input device of the present invention.

FIG. 2 is a diagram illustrating functions of a zoom lens in FIG.

FIG. 3 is a block diagram showing an example of an internal configuration of the image input device of FIG. 1;

FIG. 4 is a block diagram illustrating an example of the internal configuration of a personal computer.

FIG. 5 is a flowchart illustrating an image reading operation.

FIG. 6 is a diagram illustrating a range of cropping.

FIG. 7 is a diagram illustrating a process of setting a variable power in step S10 in FIG. 5;

FIG. 8 is a diagram showing a configuration of an example of a conventional image input device.

FIG. 9 is a diagram illustrating another configuration example of a conventional image input device.

FIG. 10 is a diagram showing still another configuration example of the conventional image input device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image input device 3 Carriage 4 Line light source 5 Zoom lens 6 CCD line sensor 12 Line light source 21 Documents 31, 32 Detector 33, 34 Motor

Claims (5)

[Claims] A light source for receiving light from the document and scanning in a main scanning direction; and scanning the document at a predetermined pitch in a sub-scanning direction. An image input device, comprising: a scanning unit that performs optical scanning; and an optical unit that optically forms an image of light from the document on the light receiving unit and that can continuously change the magnification. 2. The image input device according to claim 1, wherein the scanning unit sets a pitch in the sub-scanning direction to a predetermined value corresponding to a magnification of the optical unit. 3. The optical system according to claim 2, wherein the optical unit is a zoom lens capable of continuously changing a magnification.
An image input device according to claim 1. 4. An image input control device for controlling an image input device capable of continuously changing the magnification of an image from a document optically continuously, wherein first setting means for setting an optical resolution of the document to an arbitrary value. When an arbitrary value of the optical resolution of the document is not set by the first setting unit, a second setting unit that sets a maximum optical resolution, and a predetermined optical resolution is set. Control means for controlling the image input device in response to the output of the first or second setting means. 5. A recording medium on which a program of an image input control device for controlling an image input device capable of optically continuously changing a magnification of an image from a document is recorded, wherein the optical resolution of the document is set to an arbitrary value. A second setting step of setting a maximum optical resolution when an arbitrary value of the optical resolution of the document is not set in the first setting step; And a control step of controlling the image input device in response to the output of the first or second setting step so as to be set.