JPS63151170A - Picture reading method - Google Patents

Abstract

PURPOSE:To sharply read the state of the variable density of an original, and to improve the reproduced quality of a multigradation picture by reading an original picture as a variable density picture by turning it into a net point, when the original, consisting of the multi-gradation picture, is read by a hand operated scanning type reading device. CONSTITUTION:A net point sheet 20 is placed on the original 4 which has the multi- gradation picture A, and is scanned for reading by the hand operated scanning type picture reading device 1. At this time, a light beam, which has passed through the group of a transparent opening 23, among the light from the light source 6 of a picture reading part 5, is reflected by the surface of the original 4, and on the other hand, the light towards the non-transparent part 22 of the net point sheet 20 is reflected by the non-transparent part 22, and the both of them reach an image sensor 8 side respectively through a focusing lens 7. In such a state, the picture image, that the original picture is turned into the net point, is photoelectrically converted by the image sensor 8 and is stored in a buffer memory 9 according to the detected position of a position detector 10, and a respective picture data is reproduced as a binary information by printing out through a suitable printing device. Thus, the multi- gradation of the original 4 is reproduced by the variable density action of turning into the net point.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an image reading method, and particularly to an image reading method that is effective when reading a document consisting of a multi-tone image using a manual scanning image reading device. Regarding the method.

[Prior Art] Conventionally, as an image reading method using a manual scanning type image reading device, the image reading surface of the device is placed directly on the document to be read, and then the device itself is manually moved to read the document image. It is generally known that it is read as follows.

[Problems to be Solved by the Invention] By the way, the image reading unit used in conventional manual scanning image reading devices uses an image sensor or the like as a means for converting optical information from the document surface into electrical signals. However, at this time, a method was adopted in which optical information from the surface of the document was binarized using a predetermined equivalent value. For this reason, even if the original is a multi-gradation image such as a photograph, the image part with black threads is read as all black and the image part with white threads is all white, and the read image There is a problem in that the image has a different impression from the original image.

[Means for Solving the Problems] The present invention has been made in view of the above problems, and provides a method for accurately reading multi-tone images such as photographs with a manual scanning image reading device. The present invention provides an image reading method using the following methods.

That is, in the present invention, when reading the content of a document consisting of a multi-gradation image using a manual scanning image reading device, a halftone dot sheet in which a partially transparent area for halftone dots is formed is placed on the document; A manual scanning type image reading device performs a reading operation on the halftone dot sheet.

In such a technical means, the specific structure of the halftone dot sheet may be changed in design as long as it can halftone a multi-tone image with an appropriate density. Further, this halftone dot sheet may be provided as an independent member completely separate from the manual scanning image reading device, or may be attached to the manual scanning image reading device in a detachable manner.

Furthermore, the specific structure of the manual scanning image reading device may be modified as appropriate, as long as it includes at least an image reading section within the housing. Furthermore, the design of the processing method for the image data read by the image reading unit may be changed as appropriate, such as by temporarily storing the image data in memory, etc., or by directly printing it with an appropriate printing means. There is no problem. Furthermore, in order to accurately read image data, the control system for the image reading operation is desirably designed to read a corresponding image according to the moving position of the housing, in other words, the reading position of the document.

[Operation] According to the above-mentioned technical means, a document consisting of a multi-tone image is halftone-printed via a halftone-dot sheet, and in this state is read by a manual scanning image reading device.

Therefore, when an image read by a manual scanning image reading device is printed, the ``original image'' is reproduced as a multi-gradation image due to the shading effect caused by halftone dotting.

[Embodiments] Hereinafter, devices necessary for realizing the image reading method according to the present invention will be described in detail based on embodiments shown in the accompanying drawings.

In FIGS. 1 to 3, reference numeral 1 denotes a manual scanning type image reading device, which has a movable housing 2 that is movable by running rollers 3. As shown in FIG. Inside the movable housing 2, there is an image reading section 5 for reading the image of the document 4, a buffer memory 9 for temporarily storing the image data read by the image reading section 5, and a buffer memory 9 for temporarily storing the image data read by the image reading section 5. a position detector 10 that detects positional information according to the reading position of the document 4 detected by the position detector 10; and a drive that stores the image data read by the image reading section 5 in the buffer memory 9 according to the reading position of the document 4 detected by the position detector 10. It is composed of a control section 13. In this embodiment, the image reading unit 5 includes a light source 6 for illuminating the original 4, an imaging lens 7 for forming an image of reflected light from the original 4 on a predetermined area, and an imaging area of the imaging lens 7. An image sensor 8 is used, which is placed in the image sensor 8 and converts optical information from the document 4 into binary electrical information. Further, the position detector 10 includes one of the running rollers 3, a transmission mechanism 11 consisting of a belt and a boot for transmitting the rotation of the running roller 3, and a transmission mechanism 11 that is operatively connected to the transmission mechanism 11. Additionally, an encoder 12 that detects the position of the movable housing 2 based on the number of rotations of the traveling roller 3 is used.

Further, reference numeral 20 is a halftone dot/sheet, and a non-transparent part 22 made of a non-transparent material such as white ink is formed on the surface of a transparent film 21 such as polyethylene in a halftone dot shape with an appropriate density (60
200 pieces/1 inch), and a large number of groups of transmission holes 23 are secured between each non-transmission part 22.

When reading the image of the original 4 using such a device, if the original 4 has a multi-tone image A such as a photograph, the halftone dot sheet 20 is placed on the original 4 as shown in FIG.
The manual scanning image reading device 1 is manually moved on the halftone dot sheet 20 to read the corresponding original 4.
What is necessary is to read and scan a portion. At this time, out of the light from the light source 6 of the image@reading section 5, the halftone sheet 2
As shown by the solid line in FIG. 4, the light passing through the transmission apertures 23 group of 0 is reflected by the 4 surfaces of the document and then passes through the imaging lens 7 toward the image sensor 8. On the other hand, the light from the light source 6 Of the light, the light directed toward the non-transparent part 22 of the halftone dot sheet 20 is
As shown by the dashed line in FIG. 4, after being reflected by the non-transmissive portion 22, the light reaches the image sensor 8 side via the imaging lens 7.

In this state, a halftone image of the original image is input to the image sensor 8, and the image data photoelectrically converted by the image sensor 8 is stored in the buffer memory based on the detected position of the position detector 10. It is stored in 9. Then, if the image data stored in the buffer memory 9 is printed out via an appropriate printing device, each image data is reproduced as binary information, but in the first place each image data is halftone-printed. 1 of halftone dotting.
The multi-tone image of the original [4] is reproduced by the lightening effect.

In addition, when the original 4 is a binary image such as a line image, the manual scanning image reading device 1 is placed directly on the original 4 without using the halftone dot sheet 20, and reading scanning is performed. Just do it.

Further, FIGS. 5 to 7 are explanatory diagrams showing modifications of the manual scanning type image reading device 1 necessary when applying the present invention.

In the figure, a manual scanning image reading device 1 also serves as a scanner section S of a copy machine, and connectors 30, 31
The copying machine main body Bl: is detachably connected to the main body Bl of the copying machine via the main body Bl of the copying machine.

The manual scanning image reading device 1 in this modified example includes a light source 6, an imaging lens 7, and an image sensor 8, as in the embodiment.
an image reading section 5, a buffer memory 9 for temporarily storing the image data read by the image reading section 5, a position detector 10 for detecting the reading position of the document 4, and a position detector 10 for detecting the reading position of the document 4; The drive controller 13 includes a drive control section 13 that performs an image reading operation based on the information. In FIG. 7, reference numeral 15 denotes a video processing circuit (not shown in the embodiment) for video processing the electric signal from the image sensor 8 and storing it in the buffer 7 memory 9; This is the control panel for the scanner section. As shown in FIGS. 6 and 7, the copying machine main body B also includes a printing section 32 that performs a printing operation, a document feeding mechanism 33 that supplies the document 4 to the scanner section S, and a printing section 32 that performs a printing operation. Paper feeding mechanism 3 that supplies recording paper 34 to section 32
5, a main body control section 36 that controls the reading operation, printing operation, document feeding operation, paper feeding operation, etc. of the scanner section S mounted on the copying machine main body section B, and operating each control operation of the main body control section 36. A control panel 37 is provided.

In this modification, the printing section 32 includes a thermal print head 32a, a platen roll 32b disposed opposite to the thermal print head 32a, and a recording medium supply system 32c such as an ink donor film. Further, the document feed mechanism 33 includes a document table 33a, a document feed roll 33b, a document discharge tray 33C, and the like. In addition, the paper feeding mechanism 35
consists of a paper feed cassette 35a, a paper supply roll 35b, a paper ejection tray 35c, and the like.

According to this modification, from the copying machine main body part B to the scanner part S
If separated, this scanner section S functions as the manual scanning image reading device 1 as in the embodiment, while if the copying machine main body section B and scanner section S are connected, the main body control section 3 functions as the main body control section 3.
6, the scanner section S and the document feeding mechanism 33 are controlled to read the document 4, and the image data of the document 4 is stored in the buffer memory 9. Thereafter, the printing unit 32 and paper feeding mechanism 35 are controlled by the main body control unit 36, and the image data stored in the buffer memory 9 is transferred to the recording paper 34.
are printed sequentially.

[Effects of the Invention] As described above, according to the image reading method of the present invention, when reading a document consisting of a multi-tone image with a manual scanning image reading device, the document image is converted into a gray scale image by halftone dotting. Therefore, the shading state of the original can be read sharply without being affected by the type of the original, and the quality of the multi-gradation image to be reproduced can be kept good accordingly.

[Brief explanation of the drawing]

FIG. 1 is a perspective explanatory view showing an embodiment of a device necessary for realizing the image reading method according to the present invention, and FIG. 2 is a cross-sectional view showing a specific example of a manual scanning image reading device used in the embodiment. Figure 3 is an explanatory view of the main part showing a specific example of the halftone dot sheet used in the example, Figure 4 is an explanatory view showing the reading operation process of the device in the example, and Figure 5 is a manual scanning image. An explanatory diagram showing a modified example of the reading device, FIG. 6 is an explanatory diagram showing a state in which the manual scanning type image reading device according to the modified example is incorporated into the main body of the copying machine, and FIG. 7 is an explanatory diagram showing a manual scanning type surface in the modified example. (g
? FIG. 2 is a functional block diagram showing the relationship between a reading device and a main body of a copying machine. [Explanation of symbols] (1)...Manual scanning type image reading device (2)...Movable housing (4)...Document (5)...Image reading section (9)...Buffer memory ( 10) Position detector (13) Drive control unit (20) Halftone sheet patent applicant Fuji Xerox Co., Ltd.
Patent attorney Tomohiro Nakamura (2 others) 1: Hand mt hair l! Figure 5 Figure 6 L-j

Claims (1)

[Claims] When reading the content of a document consisting of a multi-tone image using a manual scanning image reading device, a halftone dot sheet on which a partially transparent area for halftone dots is formed is placed on the document, and manual scanning is performed on this halftone dot sheet. An image reading method characterized in that a reading operation is performed by a scanning type image reading device.