JPH02265366A - Picture input device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image input device equipped with a decomposition optical system for enhancing the outline of an image signal when scanning calligraphy and converting it into an electrical signal. be.

2. Description of the Related Art Conventionally, in color separation scanners for printing, shade scanners, and the like, a contour signal enhancement processing method called an unsharp mask method has been commonly used as a means for correcting the sharpness of an image.

FIGS. 6(a) to 6(f) show the principle of the unsharp mask method. The image is scanned by an optical system having two apertures, one large and one small, as shown in FIG. 2(a).

107 is a sharp aperture having a predetermined resolution, and when scanning an ideal black and white pattern as shown in FIG. 6), a sharp signal as shown in FIG. 6(c) is obtained. On the other hand, 108 is an unsharp aperture with lower resolution than the sharp aperture 107, and when scanning the pattern shown in FIG. A bad unsharp signal (blurred signal) is obtained. Therefore, by creating a differential signal between waveforms (c) and (d), a kind of differential signal as shown in (e) in the same figure is obtained. By adding this to the sharp signal (e), the contour characteristics are emphasized. An image signal (f) is obtained. This effect is not limited to the case of a rectangular wave signal as shown in FIG. 2(b); it emphasizes the contrast in a portion where the gradient of the grayscale change of the image signal is steep, producing the effect of visually increasing the sharpness.

The optical path of the scanning optical system at this time will be explained with reference to FIG.

The light source 102 is lit by a 2-amp power supply (not shown),
The light from the light source 102 is irradiated onto the original 101 as a luminous flux 103. The light beam 103 irradiated on the original 101 is reflected by the surface of the original, and the reflected light beam 104 is condensed by the reading lens 105 of the decomposition system 111, and a real image of the reading pixel 1010 of the original 101 is projected onto the sharp aperture 107 provided in the focal plane. tie.

Since the sharp aperture 107 has a hole of an appropriate size, the photoelectric converter 109 obtains a sharp signal of the read pixel 1010 resolved with a corresponding resolution.

On the other hand, the light beam 104 that has passed through the reading lens 105 is separated by a half mirror 106 and forms a real image of the reading pixel 1010 also on an unsharp aperture 108 provided on the focal plane.

Unsharp aperture 108 is sharp aperture 1
Since the hole is larger than that of 07, the photoelectric converter 110 can obtain an unsharp signal (blur signal) of the read pixel 1010 resolved with a corresponding resolution.

Here, the reading resolution of the image input device is closely related to the feed amount of the resolving system 111 and the diameter of the sharp aperture 107. For example, the reading resolution is 10 lines/m.

When the magnification of the reading lens 105 of the decomposition system 111 is 1:4, the feed amount of the movable table on which the decomposition system 111 is mounted is 0.1.
The diameter of the sharp aperture 107 should be 0.4 mm. As will be clear from this, when you want to change the reading resolution arbitrarily, each aperture 10
7 and 108 must be replaced.

Therefore, in order to deal with this, the present applicant first developed a sharp aperture 107 and an unsharp aperture 108.
We have applied for a patent for an aperture block exchange method that consists of an integrated structure and each has an optical axis adjustment function. The outline will be explained using FIG. 8.

The sharp aperture 107 and the unsharp aperture 108 are each fixed to an aperture holder 112. Aperture holder 112 is aperture block 1
13, the optical axis can be aligned with the center of the holes of the sharpened aperture 107 and the unsharp aperture 108 using the adjustment screw 114. A plurality of types of aperture blocks 113 are prepared, and each aperture block 1
A sharp aperture 107 and an unsharp aperture 108 having different hole diameters are fixed in the aperture block 13, and by replacing the aperture block 113 as necessary, it is possible to configure a resolving system with different reading resolutions.

Problems to be Solved by the Invention However, in the above configuration, a plurality of types of aperture blocks must be prepared in order to display the aperture blocks, which is not only complicated to handle but also causes an increase in costs. Further, the structure of the aperture block is complicated, and there is a problem in that the optical axis of each aperture block must be adjusted.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide an image input device that has a simple structure and is capable of responding to changes in reading resolution by arbitrarily selecting the diameter of the aperture diaphragm. be.

Means for Solving the Problems The present invention provides a light source that irradiates light onto a document, a reading lens that reads the irradiated surface of the document, a half mirror that divides the light condensed by the reading lens into two, and a light source that irradiates light onto a document. The aperture includes a sharp aperture and an unsharp aperture that narrow down the light emitted from the aperture, and a photoelectric converter that converts the light emitted from the aperture into an electrical signal. Each aperture is correspondingly arranged on the same circumference of two plate-shaped holders.

According to the above structure, when one disc-shaped holder is rotated, the other disc-shaped holder is rotated in conjunction with the other disc-shaped holder, and each aperture has a different diameter depending on the size, resolution, and type of the document to be read. can be selected arbitrarily.

EXAMPLE An example of the present invention will be described below with reference to the drawings.

FIG. 2 is a perspective view of an image input device according to an embodiment of the present invention, showing the arrangement of each member.

In FIG. 1, a document 1 is wound around a cylindrical drum 2 and can be rotated in the direction of the arrow by a main scanning motor 3. A light source for illuminating the original 1, a reading lens for reading, and a photoelectric converter are housed in the decomposition system 4.
The original image light read by this decomposition system 4 is converted into an electrical signal. The decomposition system 4 is loaded on a moving table 9 and moved parallel to the axis of the tram 2 by means of a sub-scanning screw 5. Scanning of the document 1 is performed by rotating the drum 2 by a main scanning motor 3 and moving a sub-scanning section including a disassembly system 4 and the like from side to side by a sub-scanning screw 5 rotated by a sub-scanning motor 6.

Figure 1 shows the decomposition system 4 of the overall configuration diagram shown in Figure 2.
FIG. 3 is a perspective view showing this in more detail, and FIG. 3 is a plan view thereof. The light source 7 is turned on by a lamp power source (not shown), and the light from the light source 7 is irradiated onto the original 1 as a luminous flux 8 . The light beam 8 irradiated onto the original 1 is reflected by the surface of the original, and the reflected light beam 8 is condensed by the reading lens 11 of the decomposition system 4, and is focused on the reading pixel 1 by sharp apertures 14a, 14b, . . . provided in the focal plane.
Connect the real image of 0.

Since the sharp apertures 14g, 14b, . . . have holes of appropriate sizes, the photoelectric converter 17 obtains sharp signals of the read pixels 10 resolved with a corresponding resolution.

On the other hand, the light beam 8 that has passed through the reading lens 11 is a half mirror.
19, and the real image of the reading pixel 10 is focused on unsharp apertures 15a, 15b, . . . provided on the focal plane.

Since the unsharp apertures 15a, 15b, . . . have holes about three times the size of the sharp apertures 14a, f4b, . A sharp signal (blur signal) can be obtained.

The above-mentioned sharp apertures 14a, 14b... have several types (four types in the illustrated example) of different hole diameters, and each of the sharp apertures 14a to 14d is installed on the same circumference of the disc-shaped holder 2. . Shaft 1 of holder 12
3a is supported in a fixed position, and each aperture 14a to 14 is opened by rotating this holder 12 around the rotation of the shaft 13a.
d can be arbitrarily selected. Similarly, the unsharp apertures 15a, 15b, . . . are also installed in the disc-shaped holder 16 and configured to rotate around the shaft 13b.

As shown in FIG. 3, the disc-shaped holders 2 and 16 are each provided with teeth on their outer peripheries and have a structure in which they mesh with each other. When the disc-shaped holder 12 is rotated, the disc-shaped holder 1
6 is structured to rotate in conjunction with each other. Although the present embodiment has been described using a tooth transmission mechanism, it goes without saying that a friction transmission mechanism or a belt transmission mechanism may also be used for interlocking.

By rotating the disc-shaped holder 12 in this way, when the sharp apertures 14a to 14d of an arbitrary hole diameter are selected, the unsharp apertures 15a to 15d can also be automatically selected, making it easy to adapt to changes in reading resolution. At the same time, it is possible to prevent the occurrence of moire fringes depending on the type of document l.

In addition, the disk-shaped holder 12 may be rotated by rotating the disk-shaped holder 16 conversely, or may be rotated independently without interlocking. Further, the holders 12 and 16 are not limited to a disk shape, but may have an arbitrary shape such as a rectangle.

FIG. 4 shows another embodiment of the invention. Components in the figure that are the same as those in FIG. 3 are designated by the same reference numerals, and explanations thereof will be omitted. In this embodiment, a disc-shaped holder 2 is rotated by a drive motor 21. According to the configuration, before inputting an image, the original 1 is scanned to read the dot pitch (print particles) and to eliminate moire fringes. Sharp apertures 14a to 14d and unsharp apertures 15a to 15d with hole diameters to be avoided are determined, and the disc-shaped holder 12 is rotated by the drive motor 21 in accordance with the hole diameters to avoid sharp apertures 14a = 14d and unsharp apertures 15a to 15d. It is configured so that it can be selected automatically.

FIG. 5 shows yet another embodiment of the invention. Components in the figure that are the same as those in FIG. In this embodiment, disc-shaped holders 12 and 16 are spaced apart from each other, and each is rotated separately by drive motors 21 and n. In this case as well, KWJ
By scanning the original 1 and reading the dot pitch before inputting the image, and rotating each drive motor 21, 22 in synchronization with the dot pitch, the desired sharp apertures 14a to 14d1 and unsharp apertures 15a to 15d can be automatically set. You can choose.

Effects of the Invention As is clear from the above explanation, the present invention provides a plurality of types of apertures having different hole diameters arranged on the same circumferential portion of a disc-shaped holder, and each aperture can be adjusted arbitrarily according to the rotation of the disc-shaped holder. Because it has a selectable configuration, the diameter of the diaphragm can be arbitrarily selected with a simple structure without the need for complicated diaphragm mechanisms or replacement work as in the past, making it possible to adapt to changes in reading resolution. I can do it.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the overall configuration of an image input device according to an embodiment of the present invention, FIG. 2 is a perspective view of a scanning system in the same device, FIG. 3 is a plan view of the overall configuration of the same device, and FIG.
FIG. 5 is a plan view showing the overall configuration of an image input device according to another embodiment of the present invention, FIG. 5 is a plan view showing the overall configuration of an image input device according to still another embodiment of the present invention, and FIG. A signal waveform diagram showing the contour signal correction operation using the mask method; FIG. 7 is a plan view of the decomposition system of a conventional image input device;
FIG. 8 is a perspective view of the aperture block according to the prior application. DESCRIPTION OF SYMBOLS 1... Document, 2... Drum, 3... Main scanning motor, 4... Decomposition system, 5... Sub-scanning screw, 6... Sub-scanning motor, 7... Light source, 8 ... Luminous flux, 9... Moving table, 10... Reading pixel, 11... Reading lens, 12
...Disk-shaped holder, 13a, 13b...Shaft, 14a
〜14b...Sharp aperture, 15a〜15d・
... Unsharp aperture, 16... Disc-shaped holder, 17.18°... Photoelectric converter, 19... -7 mirror, 21°η... Drive motor. Figure 1 Name of agent Patent attorney Shigetaka Awano and 1 other person Figure 1 Figure 6 Figure 6

Claims (3)

[Claims] (1) A light source that irradiates light onto the original, a reading lens that reads the irradiated surface of the original, an optical system that divides the light focused by the reading lens into two, and a sharp aperture and an amplifier that narrow down the focused light. A sharp aperture, and a photoelectric converter that converts light emitted from each of the apertures into an electrical signal, each of the apertures having a plurality of types of holes having different diameters formed on substantially the same circumference. An image input device comprising a flexible plate-shaped holder. (2) A first aperture in which a plurality of sharp apertures with different diameters corresponding to sharp signals are formed on substantially the same circumference.
and a second plate-shaped holder in which a plurality of unsharp apertures having different hole diameters corresponding to unsharp signals are formed on substantially the same circumference, the first plate-shaped holder 2. The image input device according to claim 1, wherein the second plate-shaped holder rotates in conjunction with the second plate-shaped holder. (3) The image input device according to claim 2, wherein the first plate-shaped holder and the second plate-shaped holder are each rotated synchronously by a drive motor.