JPH06217082A - Color picture inputting device - Google Patents

Abstract

PURPOSE:To provide a color picture inputting device in which picture data whose quality is satisfactory without any vertical stripes can be obtained even at the time of reading a picture at a high speed. CONSTITUTION:In a color picture inputting device A', at the time of obtaining the picture data by scanning a color original 1 by successively resolving a light from the color original 1 into plural chrominance components by a color resolving filter unit 5, and image-forming it on a CCD linear image sensor 4 constituted of plural picture elements, a mutual influence between each color can be reduced by a dummy scan 6 provided between each chrominance component element of the color resolving filter unit 5. Thus, the picture data whose quality is satisfactory without any vertical stripes can be obtained even at the time of reading the picture at the high speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image input device, and more particularly to a color image input device used in a color image processing device such as a color facsimile or a color image scanner.

[0002]

2. Description of the Related Art Conventionally, a color original is irradiated with light, and reflected light or transmitted light from the original is separated into a plurality of color components by a color separation filter and is scanned. A color image input device is known in which image data is obtained by forming an image on a document and reading a color image on a document for each color component. FIG. 1 is a schematic diagram showing a schematic configuration of an example of the conventional color image input device A as described above, FIG. 4 is a plan view of a color separation filter unit of the conventional color image input device A, and FIG. It is a schematic diagram which shows schematic structure of an image sensor. In FIG. 1, the light emitted from the light source 2 to the reading line on the color original 1 is transmitted through the original surface and then condensed by the lens system 3 to form an image on the CCD linear image sensor 4 which is an image sensor. To do. The color separation filter unit 5 in the path of the imaging optical system is attached near the lens system 3. As shown in FIG. 4, the color separation filter unit 5 includes filters 5r for three primary colors of red (R), green (G), and blue (B),
5g and 5b are arranged, and by rotating around the rotary shaft 7, the filters 5r, 5g and 5b can be sequentially placed on the optical path. Therefore, the color image on the original 1 can be read by the CCD linear image sensor 4 for each color component. The inside of the CCD linear image sensor 4 has a structure as shown in FIG. 5, and first, charges proportional to the amount of incident light are accumulated in a capacitor C of a sensor unit S including a plurality of pixels P, P, .... Next, the charges accumulated in the capacitor C are transferred to the CCD analog shift register R. Then, by sequentially moving this charge in the CCD analog register R at a predetermined timing, a signal proportional to the amount of incident light of each pixel P, P, ... Is taken out. In this way, image data (signal) for each scan
I was able to get

[0003]

In the conventional color image input apparatus A as described above, when an image is read at a high speed, vertical stripes having periodicity may occur in a highly saturated portion of the image. . This is because when the electric charges are transferred from the sensor unit S of the CCD linear image sensor 4 to the CCD analog shift register R, some of the electric charges remain in the sensor unit S as they are without transferring all the electric charges, and the electric charges at the time of the next scanning are changed. It's because it gets mixed in. Moreover, each pixel P, P,
Since there is a variation in the ratio of the remaining charge between R, G, and
In the case of the original 1 having a large difference in the signal level of each color of B, each pixel P, P, ... Has a different color. For this reason, the portion of the pixel P where a large amount of electric charge remains may be seen as a vertical stripe. In order to solve the problems in the prior art, the present invention has improved a color image input device and provides a color image input device which can obtain high-quality image data without vertical stripes even when an image is read at high speed. It is intended to be provided.

[0004]

In order to achieve the above object, the present invention obtains image data by scanning light from a color original while sequentially separating the light into a plurality of color components while separating them into a filter and forming an image on an image sensor. The color image input device is configured as a color image input device characterized in that a light shielding region is provided between the color component elements of the filter.

[0005]

According to the present invention, when the light from a color original is sequentially separated into a plurality of color components while being scanned and scanned to form image data on the image pickup device, each color component element of the filter is obtained. It is possible to eliminate mutual influence between the respective colors by the light-shielding area provided between them, and to remove the component causing the vertical stripes of the image from the output signal of the image pickup device. As a result, high-quality image data with no vertical stripes can be obtained even when the image is read at high speed.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. The following embodiments are examples of embodying the present invention and are not intended to limit the technical scope of the present invention. Here, FIG. 1 is a schematic diagram showing a schematic configuration of a color image input device A'according to an embodiment of the present invention (shared with a conventional example), and FIG. 2 is a plan view of a color separation filter unit of the color image input device A '. A structural diagram and FIG. 3 are graphs showing the change over time in the amount of charges accumulated in the sensor portion of the CCD linear image sensor. As shown in FIG. 1, a color image input device A'according to this embodiment.
Is light source 2, lens system 3, CCD linear image sensor 4
(Equivalent to an image pickup device) and a color separation filter unit 5 are provided, and image data can be obtained by capturing an image on the CCD linear image sensor 4 through the color separation filter unit 5 that rotates the light from the color original 1. Similar to the example. However, the present embodiment is different from the conventional example in that the dummy scan 6 which is a light shielding region is provided between the color component elements of the color separation filter unit 5 as shown in FIG. Less than,
The basic principle of the operation of this device A'will be described. The amount Q of accumulated charges in the sensor portion S of the CCD linear image sensor 4 described above changes with time as shown in FIG. In the figure, the sensor unit S of the CCD linear image sensor 4
When the light is incident on, the accumulated amount Q increases to a level according to the color component and becomes saturated. Next, from the sensor section S to the CCD
When the charges are transferred to the analog shift register R at a predetermined timing, the accumulated amount Q is reduced and becomes zero accordingly.
Here, when the scanning speed is increased in order to read an image at high speed, the timing of transferring the charges is advanced, but the reduction rate of the accumulated amount Q does not change. Therefore, while the accumulated amount Q is decreasing, the light from the next scan is incident on the sensor section S, and as shown in FIG. Be added. The degree of influence of the residual amount ΔQ ′ of the added charge on the output signal of the CCD linear image sensor 4 depends on the magnitude of the difference in signal level corresponding to the color of the incident light.

That is, there is a large difference in the signal levels of the three colors of red (R), green (G), and blue (B), and light of a large signal level is followed by light of a small color of the same level. Remaining charge Δ
The influence of Q is particularly large, and at this time, vertical vertical stripes with periodicity are generated in the highly saturated portion of the image. By providing a light-shielding region between the R, G, and B filters 5r, 5g, and 5b of the color separation filter unit 5 to provide a scanning interval, the residual amount ΔQ of the charge remaining in the next scanning can be reduced. it can. For example, when a black (Bk) filter that completely blocks light is used as the light-shielding region, as shown in FIG. 3C, the accumulated amount Q of charges in the sensor unit S of the CCD linear image sensor 4 is next. It becomes almost zero by the time of scanning and is not added to the next scanning. Using the above principle, the device A ′ of this embodiment is
As shown in FIG. 2, black (B) is provided between the filters 5r, 5g, 5b between the colors of the color separation filter unit 5.
k) Insert a dummy scan 6 such as a filter. This dummy scan 6 eliminates mutual influence between each color,
From the output signal of the CCD linear image sensor 4, a component causing vertical stripes in the image (that is, the charge ΔQ remaining in the next scan)
Can be removed. As a result, high-quality image data with no vertical stripes was obtained even when the image was read at high speed. Although the black (Bk) filter is used as the dummy scan 6 in the above embodiment, the signal level difference may be reduced by using a filter corresponding to the intermediate signal level of the front and rear scans in actual use. In the above embodiment, the color separation filter unit 5 of three colors of RGB is rotated and used, but in actual use, there is no problem even if another type of filter is used.

[0008]

Since the color image input apparatus according to the present invention is configured as described above, the dummy scan inserted between the color component elements of the color separation filter unit eliminates the mutual influence between the colors. , It is possible to remove the component (that is, the charge remaining in the next scan) that causes the vertical stripes in the image from the output signal of the CCD linear image sensor.
As a result, high-quality image data with no vertical stripes can be obtained even when the image is read at high speed.

[Brief description of drawings]

FIG. 1 is a schematic view showing a schematic configuration of a color image input device A ′ according to an embodiment of the present invention (shared with a conventional example).

FIG. 2 is a plan structure diagram of a color separation filter unit of the color image input device A ′.

FIG. 3 is a graph showing a change over time in the amount of electric charge accumulated in the sensor unit of the CCD linear image sensor.

FIG. 4 is a plan structural view of a color separation filter unit of a conventional color image input device A.

FIG. 5 is a schematic diagram showing a schematic configuration of a CCD linear image sensor.

[Explanation of symbols]

 A '... Color image input device 1 ... Color original document 4 ... CCD linear image sensor (corresponding to image sensor) 5 ... Color separation filter unit 6 ... Dummy scan (corresponding to light-shielding area)

Claims (1)

[Claims] 1. A color image input apparatus for obtaining image data by scanning light from a color original into a plurality of color components while sequentially separating the components to form image data on an image sensor, and between the color component elements of the filter. A color image input device comprising a light-shielding region.