JP3482966B2 - Image reading device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus which divides a document image and picks up the image and combines the divided images to obtain one document image data.

[0002]

2. Description of the Related Art Conventionally, a divided image pickup type image reading apparatus has been developed in which an original image is divided and picked up, and then the divided images are combined to obtain one original image data.
In particular, the image input device is suspended on a fixed base, and the image input device is operated so as to swing its head vertically and horizontally to scan the original document, input divided images, and combine them to obtain one original image data. The image reading apparatus configured to obtain the image pickup apparatus is compact and has a high degree of freedom in installation location.

FIG. 4 is an external view of a conventional split image-type image reading apparatus. In the figure, 41 is a movable reading head, 42 is a column, 43 is an image processing device, and 44 is a document.

The column 42 is provided vertically on the image processing device 43, and the movable reading head 41 is attached to the upper end of the column 42 so as to swing vertically and horizontally. The document 44 is placed by the user at a position where it is read by the movable reading head 41.

Such a conventional image reading apparatus is fixed near an information device such as a computer terminal or a workstation to be connected, or in a form attached thereto, fixed to an appropriate height and installed. It Such information equipment is usually installed on a desk.

When the original 44 is read, the movable reading head 41 is swung left and right to sequentially move the reading area, and the original 4 is read at each reading position.
4 is two-dimensionally scanned to obtain a divided image at each position. When the reading of the strip-shaped area is completed by one swinging motion on the left and right, the movable reading head 41 is swung up and down,
The original 44 is read while the reading area is sequentially changed by the right and left swinging motion again. In this way, by the vertical and horizontal swinging motions, the divided image of each area is obtained while changing the reading area. After the reading is completed, the image processing device 43 performs geometric correction according to the angle of view on the divided and picked-up images and joins the divided images to obtain one read image data.

In the image processing device 43, the height from the surface of the manuscript 44 of the movable read head 41 is known when the divided images are joined after geometric correction such as correction of geometric distortion. Is being processed as This is because the conventional image reading device has a fixed height. Therefore, in order to adjust the angle of view during reading and scanning,
Zoom in and out to some extent, but
Due to the limitations of the zoom ratio, the necessary adjustments cannot be made. It is possible to move the original on a horizontal plane or change the height of the table on which the original is placed, but it is necessary to detect the data of the moving distance and the height of the table, and adjustment is possible with a simple operation. You cannot do it. Therefore, in the conventional image reading apparatus, it is impossible to enlarge a part of the original and input with high resolution, which is a great obstacle to operability.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an image reading apparatus in which the angle of view can be easily adjusted during a reading operation.

[0009]

According to a first aspect of the present invention, in an image reading apparatus, an image input apparatus for dividing and inputting an original image and an image input apparatus for scanning the original are provided. A driving mechanism for moving the head in a vertical and horizontal direction, a suspension means for suspending the image input device and capable of changing at least the distance between the document and the image input device, and the suspension means. There is an image synthesizing unit for geometrically correcting the divided images input from the image input device based on a parameter such as a distance between the document and the image input device and synthesizing the divided images into one original image. However, the image synthesizing means determines whether or not the divided image is the entire background, and if the entire surface is the background, the geometric correction is not performed. As the suspension means, a suspension mechanism that can slide vertically and horizontally can be used. The detection of the distance between the original and the image input device can be calculated based on the distance to the original detected by the automatic focusing mechanism.

According to the second aspect of the invention,
In the image reading device, the suspension means in the invention according to claim 1 is configured so that at least the distance and angle between the document and the image input device can be changed, and in the image composition means, the suspension means sets the suspension means. The divided images input from the image input device are geometrically corrected based on parameters such as the distance and angle between the original and the image input device, and the divided images are combined into one original image. In this case also, it is characterized in that whether or not the divided image is the entire background is determined, and if the entire surface is the background, the geometric correction is not performed. As a suspension means that can change the distance and angle,
A free mechanism having 2 to 4 rotary shafts in vertical or horizontal directions can be used. The angle detection can be configured by equipping each of the horizontal rotation axes with a detector that detects the rotation amount.

[0011]

According to the present invention, since the distance between the document and the image input device, or the suspension means capable of changing the distance and the angle is provided, the relative positional relationship between the document and the image input device can be freely adjusted. Therefore, it is possible to realize high operability in the reading operation, and it is possible to realize the range resolution change which cannot be achieved by the view angle adjustment by zooming. Also, when performing geometric correction processing on divided images, it is determined whether the divided image is the background over the entire surface, and if the entire surface is the background, geometric correction is not performed. It can be configured so as not to perform a process that does not exist.

[0012]

FIG. 1 is an external view showing an embodiment of an image reading apparatus of the present invention. In the figure, 1 is a movable reading head, 2 is a suspension mechanism, 3 and 4 are horizontal rotation axes, 5 is a vertical rotation axis, and 6
Is an image processing apparatus, and 7 is a document.

The movable reading head 1 is driven to swing its head up and down, left and right, and divides an image on the original 7 to read it. In this embodiment, the scanning of the original 7 is performed in the same manner as in the conventional method described with reference to FIG. The operation of shaking the head and reading the next image of a certain width while dividing the area is repeated. Therefore, a surface sensor is used for the photoelectric conversion unit.

However, the photoelectric conversion unit is not limited to the surface sensor, but may be a line sensor or an FSS (flying
Spot scanner) or the like can be used. When the surface sensor is used, as described above, the area that can be imaged by the surface sensor is divided and read, and each time the reading is completed, the sensor is moved left and right or up and down for scanning. When using a line sensor, FSS, etc., 1
Since it will be read for each pixel row, one swivel on the left and right will read one strip-shaped or linear image,
This is synthesized.

The movable reading head 1 is equipped with an automatic focusing mechanism for automatically reading on the original 7 while measuring the distance to the original 7 at the time of focusing. The distance data is sent to the image processing device 6 together with the read image. Furthermore, a zoom mechanism can be added.

The suspension mechanism 2 has one end fixed to the image processing device 6 and the other end provided with a movable reading head 1. Further, the suspension mechanism 2 shown in FIG. 2 has two horizontal rotation shafts 3 and 4 and one vertical rotation shaft 5, and between the rotation shafts and between the rotation shafts 3 and the movable read head 1. The arms are connected to each other, and the rotating shaft 5 is provided between the rotating shaft 5 and the image processing device 6. Here, the horizontal axis of rotation means that the axis for rotating the document 7 is horizontal, and the horizontal axis of rotation causes the arm to move up and down. Similarly, the vertical rotation axis means rotation around an axis perpendicular to the original 7.
The vertical axis of rotation allows the entire suspension mechanism 2 to move laterally. With such a suspension mechanism 2, the user can move the movable reading head 1 up and down, left and right, and back and forth, and can arrange it at a desired position or height. The number of horizontal rotation axes is not limited to two, and may be determined according to the operability of moving the movable reading head 1 or the like, but any number of three or more may be used, but from the viewpoint of operability, about 2 to 4 is suitable. Is.

In this embodiment, the vertical axis of rotation is the base, and the others are only horizontal axes of rotation. Therefore, no matter how the individual axes of rotation are rotated, the distance and angle only change and the twisting occurs. Is not added, and the calculation is simple.

Further, the horizontal rotation shafts 3 and 4 of the suspension mechanism 2 are provided with rotation detectors for detecting the amount of rotation so that the angle at which the movable read head 1 is arranged can be detected. Has become. The detected angle data is sent to the image processing device 6. The movable reading head is provided with a gyro and controls the posture of the head.

The image processing device 6 performs geometrical correction on the images picked up by the movable reading head 1 in a divided manner and performs a joining process to obtain a read image. Here, data on the position of the movable read head 1 is required to perform the geometrical correction. First, as the angle data, the angle data detected by the rotation detectors attached to the horizontal rotation shafts 3 and 4 is input. Further, as the height data, the distance data detected by the automatic focusing mechanism provided in the movable reading head 1 is input. The image processing device 6 obtains the height of the movable reading head 1 from the document surface and the estimated angle based on these two signals, and performs geometric correction. Positions that are horizontal to the document surface only appear as image misalignment, and by correcting the position of the document or the movable read head, or specifying the reading range,
Can be corrected. Further, the correction of each pixel in the divided picked-up image is performed geometrically by taking into account the vertical and horizontal swing data of the movable reading head 1.

In this embodiment, the movable read head 1 can be moved by the suspension mechanism 2 in the front-rear direction, the left-right direction, and the up-down direction. Depending on the setting of the rotation axis provided in the suspension mechanism 2,
It can also be configured to rotate the movable read head. In that case, install a rotation detector on each rotary shaft,
It is necessary to obtain the rotation amount and the posture of the movable reading head 1. With this configuration, the amount of calculation required for geometrical correction increases, and the processing algorithm by the image processing device 6 also becomes complicated. Actually, if the degree of freedom is about the above-mentioned embodiment, there is not much problem in operation.

FIG. 2 is an external view showing another embodiment of the image reading apparatus of the present invention. The same parts as those in FIG. In the figure, 8 is a vertical movement mechanism,
9 is a horizontal movement mechanism.

The suspension mechanism 2 is composed of a vertical rotary shaft 5, a vertical movement mechanism 8 and a horizontal movement mechanism 9. The movable reading head 1 is disposed on the horizontal movement mechanism 9, and the lower part of the vertical movement mechanism. Is fixed to a vertical rotary shaft 5. The vertical movement mechanism 8 can change the height of the horizontal movement mechanism 9 and the movable read head 1. Further, the horizontal moving mechanism 9 allows the movable reading head 1 to be arranged on the original 7. With this suspension mechanism 2, without changing the relative posture of the movable reading head 1 with respect to the document,
The relative position to the original is variable.

Instead of using the vertical rotating shaft 5, a horizontal moving mechanism that moves in a direction perpendicular to the vertical moving mechanism 8 and the horizontal moving mechanism 9 may be provided. This horizontal movement mechanism is used as the X axis, the vertical movement mechanism 8 is used as the Z axis, and the horizontal movement mechanism 9 is used.
The distance between the original 7 and the movable reading head 1 can be adjusted only by the linear movement mechanism in the three-axis directions with the Y axis as the Y axis. Since it is only a linear movement, the calculation is also easier.

FIG. 3 is a flow chart showing the flow of the reading and processing operations of the image reading apparatus of the present invention.

First, the user moves and positions the movable read head 1. Then, in Step 21, the resolution is designated by a setting device (not shown).

In Steps 22 and 23, the entire visual field is scanned and displayed on the display device or the like. At this point, the position of the movable reading head 1 can be corrected and reading can be started again. At Step 24, which part of the entire visual field is read is designated. For example, the range where the document is placed within the field of view is designated.

Step 25 is a process peculiar to the present invention, and based on the head height data detected by the automatic focusing mechanism and the angle data detected by the rotation detector,
Converts the coordinates of the specified range to be read to some fixed coordinates. Then, in Step 26, the actual size of the range to be read is calculated.

In Step 27, the inclination of the read image is detected and calculation is performed so as to correct it. In Step 28, the zoom amount is calculated from the resolution input in Step 21 and the size of the reading range, and the zoom is set.

At the above steps, the setting for the image to be read is completed. If it is not necessary to specify the reading range among the above settings, the zoom amount may be calculated and set immediately in Step 28 after the resolution is specified in Step 21. If you want to read the reading range specified in Step 24 as is,
The setting may be completed by omitting 27 and 28.

In Step 29, the range to be read is
The number of regions to be divided and imaged is calculated, and the following divided scanning is performed based on the calculation result.

First, after initialization is performed in Step 30, in Step 31, one divided area is imaged. The captured divided image is subjected to gradation correction in Step 32. Then, in Step 33, it is determined whether or not the captured divided image is the background over the entire surface, and if the entire surface is not the background, distortion correction of the divided image is performed in Step 34. At the time of this distortion correction, the correction can be performed based on the angle data of the movable reading head. If the entire surface is the background, the distortion correction process is not necessary and is not performed. The divided image is Ste
It is stored in the memory at p35.

These processes are performed for one divided area, and in Step 36, it is determined whether or not the divided scanning is completed, and St is determined until the divided scanning is completed.
The processing from ep31 to Step 35 is repeated. In the reading of the next divided area, as described above, the movable reading head 1 is operated by swinging the head horizontally and vertically.
This is performed after the imaging area on the original is moved.

When the divided scanning is completed, in Step 37, the divided images are combined and combined into one image, and the image data is output in Step 38.

In this way, reading and processing are performed, and a desired original image can be obtained.

[0035]

As is apparent from the above description, according to the present invention, the divided image pickup apparatus has the suspension mechanism capable of freely changing the height and angle from the document surface. Therefore, even if you want to adjust the angle of view of the image to be read, or if you want to enlarge a part of it or reduce the size of a large document to read it, you can do it by moving the movable reading head by hand and improve operability. The effect is that you can. Also, when performing geometric correction processing on divided images, it is determined whether the divided image is the background over the entire surface, and if the entire surface is the background, geometric correction is not performed. It can be configured so as not to perform a process that does not exist.

[Brief description of drawings]

FIG. 1 is an external view showing an embodiment of an image reading apparatus of the present invention.

FIG. 2 is an external view showing another embodiment of the image reading apparatus of the present invention.

FIG. 3 is a flowchart showing a flow of operations of reading and processing of the image reading apparatus of the present invention.

FIG. 4 is an external view of a conventional divisional image pickup image reading apparatus.

[Explanation of symbols]

1 movable reading head, 2 suspension mechanism, 3, 4 horizontal rotation axis, 5 vertical rotation axis, 6 image processing device, 7 originals, 8 vertical movement mechanism, 9 horizontal movement mechanism.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ identification code FI H04N 1/10 H04N 5/222 Z 1/107 1/10 5/222 (58) Fields investigated (Int.Cl. ⁷ , DB Name) H04N 1/387 G06T 1/00 420 G06T 3/00 200 G06T 3/00 300 H04N 1/04 105 H04N 1/10 H04N 1/107 H04N 5/222

Claims (2)

(57) [Claims] 1. An image input device for dividing and inputting a document image, a drive mechanism for operating the image input device so that the image input device swings vertically and horizontally to scan the document, and the image input device is suspended at least. Suspension means capable of changing the distance between the original and the image input device, and a divided image input from the image input device based on parameters such as the distance between the original and the image input device set by the suspension means An image synthesizing unit for synthesizing the divided images into one original image by geometrically correcting the divided images, and the image synthesizing unit determines whether or not the divided images are the entire background,
An image reading apparatus wherein the geometric correction is not performed if the entire surface is a background. 2. An image input device for dividing and inputting a document image, a drive mechanism for operating the image input device so that the image input device swings vertically and horizontally to scan the document, and the image input device is suspended at least. Suspension means capable of changing the distance and angle between the document and the image input device, and input from the image input device based on parameters such as distance and angle between the document and the image input device set by the suspension means The divided image is geometrically corrected to have an image synthesizing unit that synthesizes the divided image into one original image. The image synthesizing unit determines whether or not the divided image is a background over the entire surface. However, if the entire surface is the background, the geometrical correction is not performed.