JP2663765B2 - Scanner printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanner printer, and more particularly to a scanner capable of improving the print quality of an offset print original.

[0002]

2. Description of the Related Art In recent years, with the development of digital image processing technology, the technology has been adopted in the field of light printing, various types of scanner printers have been developed, and image data obtained by the scanner printer has been assembled. Together, they constitute necessary printing documents and the like.

[0003]

However, in the conventional scanner printer apparatus, when processing an image such as a photograph, a high quality print can be obtained by only performing gradation correction and sharpness processing. If the original to be printed is an image subjected to offset printing (screen printing), there is a problem that the image quality of the printed image is extremely deteriorated.
In other words, the scanner operation of the original is converted into image data by an image reading element such as a CCD in which the photosensitive surfaces are arranged at a constant pitch. However, when the original is an offset print image, the mesh of the screen at a constant pitch and the image reading are read. Moire patterns occur due to interference with the element pitch, and the image quality of the printed image is degraded. Conventionally, in order to remove such a moiré phenomenon, the read image data is corrected by sharpness image processing to improve the image quality. Because there are several types of meshes,
Not only does moiré removal have its limits, it also requires expensive special sharpness image processing circuitry, making scanner printers expensive. SUMMARY OF THE INVENTION An object of the present invention is to provide a scanner printer device capable of obtaining a print image of an offset print original without moiré development at low cost regardless of the type of screen in view of the above-described problems of the conventional scanner printer device.

[0004]

SUMMARY OF THE INVENTION In order to solve such a problem, the present invention provides a platen on which a document can be placed, an optical system for scanning the document on the platen, In a scanner printer including an image sensor that receives scanning pixels and converts the image data into image data, and a sharpness processing unit that processes image data from the image sensor, an adapter platen that can be placed on the platen as necessary. A scanner printer comprising a spacer which can be brought into contact with the platen, and a glass plate which is placed in a parallel relationship spaced apart from the platen by the spacer and on which the offset printing document can be placed. Is proposed.

[0005]

With this configuration, the scanned image of the original on the adapter platen is in a so-called "front focus state", and the optical image input to the image reading element is a soft image which is not affected by the mesh of the screen. State. Therefore, image data without moiré fringes can be obtained by subjecting this image data to sharpness image processing later.

[0006]

FIG. 1 shows an embodiment of a scanner printer according to the present invention. In FIG. 1, this device has basically the same configuration as a conventional scanner printer. Technical report No. 56 (August 1, 1990
This is almost the same as the configuration shown on pages 44-48 of the Japanese publication. That is, under the control of the controller 10, the motor 12 is driven, the optical unit 11 moves in the direction of the arrow along the document table 14, scans the document 15, and scans the image data consisting of binary or multi-bit gradation signals. As an output to the image processing unit 20 at the subsequent stage. The optical unit 11 includes a light source 11A, a reflector 11B, a mirror 1
1C, aperture mechanism 11D, lens 11E, aperture mechanism 11D
The reflected light from the original 15 is guided to the image sensor 11G via the mirror 11C, the aperture mechanism 11D, and the lens 11E. The image data is converted into the above-described image data by the image sensor 11 </ b> G and sent to the image processing unit 20 as an output of the optical unit 11.

The image processing section 20 has a gradation correction section 20A, 3x3 which converts the image density by acting on the obtained image data.
The sharpness processing unit 20B performs processing for finishing soft tones softly or conversely for finishing soft tones softly by the product-sum operation of the spatial filters of the input data and LU.
It has a halftone processing unit 20C that performs comparison with T (Look Up Table) and generates halftone dots.

The image data processed by the image processing section 20 is sent to the memory 30 under the control of the controller 10 and stored therein.
Is sent to the printer device 40 under the control of, and printed. There are various types of printer devices 40. For example, by mounting photographic paper on a drum and supplying the LED head with image data from the memory 30 while moving the LED head in parallel with the drum axis, the photographic paper is printed on the photographic paper. And image writing is performed. The printing apparatus having such a configuration is disclosed in the above-mentioned Iwatsu Technical Report.

The part characterized by the present invention is that the original 10 placed on the original platen 14 is
0, and a glass plate 51 placed thereon is placed on an adapter platen 55, whereby the platen is placed at a predetermined distance from the platen 14 and scanned.

With this configuration, the reflected light from the original 15 is in a so-called "front focus state", unlike an original placed directly on the original platen 14, and the optical image input to the image reading element is reflected on the screen. A soft image state where the influence of the mesh does not appear is obtained. And this image is the optical unit 1
The image data is sent to one image sensor 11G, where it is photoelectrically converted and sent to the image processing unit 20. In the image processing unit 20,
The tone correction unit 20A performs tone correction, and the tone correction data is temporarily stored in a temporary memory (not shown), and the stored data is subjected to a sharpness processing unit 20B.
Performs sharpness processing. For example, FIG.
Assuming that the gradation-corrected image data shown in (a) is obtained, these data are stored in a temporary memory such as a line memory at an arbitrary gradation level among 256 gradations, and this data is 2 (b) is calculated.

A specific example is shown in FIGS. 3 (a) and 3 (b).
For example, when X0 and Y0 in the sharpness table are matched with A of the input data, A + B + C + F + G + H + K + L + M = (0) x (2
0) + (-1) x (22) + (0) x (20) + (-
1) x (22) + (5) x (32) + (-1) x (2
5) + (0) x (36) + (-1) x (22) + (0)
x (40) = 69 Therefore, the gradation level “32” was emphasized to “69”. When X0 and Y0 in the sharpness table are matched with B of the input data, B + C + D + G + H + I + L + M + N = (0) x (2
2) + (-1) x (20) + (0) x (40) + (-
1) x (32) + (5) x (25) + (-1) x (3
0) + (0) x (22) + (-1) x (40) + (0)
x (28) = 3 Therefore, the gradation level “25” was weakened to “3”. Here, the gradation levels of the adjacent pixels G and H are
Before the sharpness processing, they were "32" and "25", but after the processing they were "69" and "3", the gradation was increased, the contrast was strengthened, and the processed image data was processed. Is an image which is harder than the read image data.

In addition to the sharpness processing, halftone processing is performed and printed out by the printer device 40 via the memory 30. As a result, a high-quality printed matter or block copy close to the original is obtained. Note that the distance of the document from the document table 14 and the content of the sharpness processing are adjusted according to the degree of occurrence of moiré.

[0013]

As described above, according to the present invention,
By simply adding the platen adapter, regardless of the type of screen, the image data of the offset-printed image original does not include the moiré phenomenon and can obtain a print image superior to the conventional one. Requires only the addition of the adapter platen according to the present invention to a conventional scanner printer having a sharpness processing circuit, so that it is possible to provide a scanner printer with a low manufacturing cost and a low selling price.

[0014]

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a scanner printer device according to the present invention.

FIG. 2 is a diagram illustrating a sharpness process.

FIG. 3 is a diagram illustrating a sharpness process.

[Explanation of symbols]

 Reference Signs List 10 Controller 11 Optical unit 11A Light source 11B Reflector 11C Mirror 11D Aperture mechanism 11E Lens 11F Motor 11G Image sensor 14 Document table 15 Document 20 Image processing unit 30 Memory 40 Printer device 50 Spacer 51 Glass plate 55 Adapter document table

Claims (1)

(57) [Claims] 1. A document table on which a document can be placed, an optical system that scans the document on the document table, an image sensor that receives a scan pixel from the optical system and converts it into image data, and an image sensor A sharpness processing unit for processing image data from the scanner printer,
An adapter platen that can be placed on the platen as necessary; the adapter platen is provided with a spacer capable of contacting the platen; And a glass plate on which an offset print original can be placed.