JPH11122430A - Image sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an inexpensive configuration which does not have noise interference by arranging and bundling one end of optical fibers that bundle plural lines so that reflected light which shows variable density or color from an image original to be read may be made incident and arranging and bundling the other end so that reflected light from an image original may be made incident on a CCD planar photosensor. SOLUTION: Optical fibers 1 make reflected light from plural lines of an image original 5 to be made incident on one end and arranges and bundles plural lines in correspondence with the matrix of photosensor elements of a planar photosensor 2 so that the reflected light may be made incident on the photosensor 2 from the other end. Illumination light from a light source 3 transmits a transparent plate 4 and illuminates an image original 5. The reflected light transmits the plate 4, is made incident on the photosensor 2 from the other end of the fibers 1 and converts variable density and color information from the original 5 into an electric signal. The one end of the fibers 1 and the source 3 move vertically by a scan mechanism and convert the entire image original 5 into electric signals.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image sensor for converting an image into an electric signal in an image reading apparatus.

[0002]

2. Description of the Related Art A large number of image reading apparatuses (scanners) for reading images such as photographs and outputting signals capable of performing image processing such as display, editing, and storage on a personal computer and copying machines for copying images are sold in the market. Have been.
In such scanners and copiers, conventionally, image information of an image document to be read is converted into an electric signal by an image sensor in which photo sensors such as CCDs are arranged in one line.

FIG. 2 is an explanatory view of a conventional image reading apparatus. In FIG. 2, reference numeral 31 denotes an image sensor having a light source illuminating in a line direction (horizontal direction) and a photosensor such as a CCD arranged in one line, 4 a transparent plate such as glass, and 5 an image original to be read. An image processing device 61 processes an output signal of the photo sensor.

The illumination light from the light source in the image sensor 31 passes through the transparent plate 4 and illuminates the image original 5. Reflected light having shades and color information from the illuminated image original 5 passes through the transparent plate 4,
The light enters the D photosensor, and one line of the image document 5 is converted into an electric signal. The image sensor 31 is moved in a vertical direction by a scanning mechanism (not shown) to convert the entire surface of the image document 5 into an electric signal. The image processing device 61 performs image processing such as display, editing, and storage of image information of the image document 5 from the electric signal.

Next, the reading speed will be described. A4 size paper has a width (line direction) of about 210 mm and a vertical width (length in the Y-axis direction) of about 290 mm. Therefore, if a resolution of 16 pixels / mm (corresponding to about 400 dpi) is obtained, A
In order to read one image original of four size paper, it is necessary to read about 15 million pixels as shown in the following calculation.

[0006] Width 210 × 16 = 3360 pixels Height 290 × 16 = 4640 pixels Overall 3360 × 4640 ≒ 15 million pixels For this reason, even with a fast image sensor, it takes 30 seconds to read one A4 size image original. For this reason, a higher reading speed is required.

[0007] A cold cathode ray tube, which is a noise source, is often used as a light source for illuminating an image document.
In order to be disposed close to each other inside the device, it is necessary to design a device to prevent noise interference from the cold cathode ray tube to the CCD photosensor.

Further, an image sensor in which CCD photosensors are arranged in one line (one line) is expensive.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive image sensor that can read data at a higher speed, does not require the above-described design for preventing noise interference, and is inexpensive.

[0010]

In order to solve this problem, an image sensor according to the present invention is mass-produced for use in a video camera or a digital still camera, and includes an inexpensive CCD planar photosensor and an optical fiber. And a light source for illuminating the image document to be read.

[0011] One end of the bundled optical fibers is arranged and bundled so that reflected light indicating shading or color from the image document to be read is incident, and the other end is reflected from the image document to the CCD planar photosensor. And bundle them so that they are incident. The optical fiber transmits an image portion of the image original in the line direction to the photo sensor elements arranged in a matrix of the CCD planar photo sensor. This CC
The image processing device that has received the electric signal from the D-plane photosensor performs image processing such as displaying, editing, and storing the read image as in the related art.

According to the present invention, it is possible to provide an inexpensive image sensor which can read at high speed and does not cause noise interference.

[0013]

DETAILED DESCRIPTION OF THE INVENTION The invention according to claim 1 of the present invention comprises a planar photosensor in which photosensor elements are arranged in a matrix, an optical fiber in which a plurality of photosensor elements are bundled, and a light source for illuminating a read original. An image sensor in which one end of an optical fiber is arranged and bundled so that reflected light from a read original is incident, and the other end is arranged and bundled so that the reflected light is incident on the flat photosensor.
The effect of being able to provide an inexpensive image sensor without noise interference is obtained.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment) FIG. 1 is an explanatory diagram of an image reading apparatus including an image sensor according to the present invention.

In FIG. 1, reference numeral 1 denotes an optical fiber in which a plurality of optical fibers are bundled, 2 denotes a video plane photosensor in which a plurality of photosensor elements such as CCDs are arranged in a matrix, and 3 denotes a plurality of lines (rows) of an image original 5. A light source such as a cold-cathode tube for illuminating, 4 is a transparent plate such as glass, 5 is an image document to be read, and 6 is an image processing device for processing an output signal of the flat photosensor 2.

The optical fiber 1 has a photosensor element of the flat photosensor 2 so that reflected light from a plurality of lines of the image original 5 is incident on one end and the reflected light is incident on the flat photosensor 2 from the other end. Plural pieces are arranged and bound according to the matrix.

The image sensor of the present invention comprises an optical fiber 1, a planar photosensor 2, and a light source 3.

Next, the operation will be described. In FIG. 1, illumination light from a light source 3 passes through a transparent plate 4 and illuminates an image document 5. Then, the reflected light having the density and color information of the image document 5 passes through the transparent plate 4 and enters one end of the optical fiber 1 (the image document 5 side). This incident light enters the planar photosensor 2 from the other end of the optical fiber 1,
The shade and color information from the image document 5 is converted into an electric signal. One end of the optical fiber 1 and the light source 3 are moved in the vertical direction by a scanning mechanism (illustration and description are omitted because it is a conventional technique). By this movement, the entire image document 5 is converted into an electric signal. The image processing device 6 receives the electric signal from the CCD planar photosensor 2 and performs image processing such as displaying, editing, and storing the image of the image document 5.

Next, the effect of improving the reading speed by the image sensor of the present invention will be described. As described in the conventional example, (3360 × 4640) pixels are read at a resolution of 16 pixels / mm from one A4 size image document. On the other hand, the CCD flat photo sensor for video is about 3
Since there are 0,000 pixels, 300,000, 3360, and 90 lines can be read at a time. However, even in consideration of image correction in the image processing device 6, 45 lines can be read in the vertical direction of the image document 5 at a time.

When reading 45 lines at a time in the vertical direction,
The entire A4 size image document can be read by moving 4640/45/100 times in the vertical direction. And C for video
Since the CD plane photosensor has a speed of 30 frames / second, if the moving time in the vertical direction is ignored, 100 {30}
An entire A4 size image document can be read in three seconds. Since the scanning time in the vertical direction is less than 1 second, the reading speed can be improved 7 times or more compared to about 30 seconds in the conventional example.

Further, since the cold cathode tube as the light source 3 and the CCD flat photosensor 2 are separated by the optical fiber 1, noise interference from the cold cathode tube to the CCD flat photosensor 2 is reduced. Can be omitted.

Further, with the flexible optical fiber 1,
Since the CCD planar photosensor 2 and the light receiving portion of the reflected light from the image document 5 are combined, there is an advantageous effect that the degree of freedom in the layout design of the CCD planar photosensor 2 is increased. For example, the manufacturing cost can be reduced by mounting the CCD planar photosensor 2 on a printed circuit board of the image processing device 6 together with other components.

[0023]

As described above, according to the present invention, it is possible to obtain an inexpensive image sensor with high-speed reading and no noise disturbance, and to provide an image reading apparatus (scanner or the like) capable of reading an image original at high speed and clearly. .

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an image reading device including an image sensor of the present invention.

FIG. 2 is an explanatory diagram of an image reading apparatus including a conventional image sensor.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 optical fiber 2 planar photosensor 3 light source 4 transparent plate 5 image document 6 image processing device 31 conventional image sensor 61 conventional image processing device

Claims (1)

[Claims] 1. A flat photosensor in which photosensor elements are arranged in a matrix, an optical fiber in which a plurality of optical sensors are bundled, and a light source for illuminating an original to be read, wherein one end of the optical fiber is read and reflected light from the original is incident. And an image sensor having the other end arranged and bundled so that the reflected light is incident on the flat photosensor.