JPS60102611A - Plane scanning optical device - Google Patents

Abstract

PURPOSE:To raise a resolution by a titled device which is small-sized, simple and inexpensive without requiring each adjustment of a lens position by dividing a linear image of an original picture onto plural CCD image sensor arrays, and projecting it by a magnification of one to one. CONSTITUTION:A long size type rod lens array 401-1 and 401-2 having an effective length equal to a scanning width of an original picture are inclined by an angle theta to each other against a perpendicular line of an original picture 406, placed in parallel to a scanning line 400, and an image 402-1 and 402-2 are formed by projecting the scanning line 400 in the respective directions. As for a long size type rod array 401, generally, (m) pieces are provided. Each sensor 403-1, 403-2 of a CCD array sensor group placed so that the photodetecting surfasce coincides with the image 402-1 and 402-2 photodetects by dividing alternately by a part each of a linear scanning line image. Each CCD array sensor 403-1, 403-2 takes a partial charge of a section of a length L/n which has divided a scanning width L into (n) equal parts. A resolution to the original picture 406 can be made almost equal to a resolution of the CCD array sensors 403-1, 403-2.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a flat scanning optical device used for reading images such as photographs and figures if+i, and for inputting image data to a divider, facunmillimeter transmitting device, and electronic scanning in printing. The present invention provides an optical device for scanning the -i1/plane with a vertical angle of 5 degrees for use in plate-making scanners and the like.

Conventional Structures and Problems Conventionally, drum-scanning mechanical scanners have been mainly used as high-resolution a-light side image reading devices required for photographic analysis of X-ray films, printing plates, and the like. This method reads reflected light or transmitted light from minute points on the surface of a document on a rotating tram by dot-sequential scanning, resulting in high resolution. However, it had drawbacks such as slow reading speed, unsophisticated scanning system, large size, and high cost.

On the other hand, recently, a plane scanning type scanner using a COD solid-state image sensor has been developed and is used for reading facsimile and other design drawings. FIG. 1 is a diagram showing its basic configuration, showing a width scanning line 100 on the document surface.
The lens 101 reduces the magnification to 1/m, and the image 102
is projected onto the light receiving surface of the QCD array sensor 103. 10
3 consists of 2048 elements, and the scanning width is 204.
A gray signal divided into 8 pixels is output. In this case, various document widths can be accommodated by adjusting the position of the lens 101 and changing the reduction ratio m, but the number of resolved pixels per -side is determined by the number of COD elements.

Therefore, it is inevitable that the larger L becomes, the larger the pixel size becomes, and the lower the resolution becomes. L=21C+++(A
The resolution is approximately 0.1 degrees on the short side of 4-size paper, but
42 cm (short side of A3 size) is 0.2ff
+'1, which is coarse, making it unsuitable for reading large-sized design drawings that require high precision.

In response to this, an input device has been developed that uses a plurality of COD array sensors arranged in a row to read a document with a large value L with high resolution, as shown in FIG. In the illustrated example, the fluorescent tube 2
The scanning line 200 on the original 206 is read by dividing it into five by six sets of lenses 201 and a COD array sensor 203, increasing the effective resolution by five times. However, this method requires a large number of expensive lens systems, and also requires a shading plate 204 (41) to correct the decrease in peripheral light intensity caused by the lenses.
However, since the optical path length from the surface of the original document 206 to the COD array sensor 203 becomes long, there is a drawback that the apparatus becomes larger.

OBJECTS OF THE INVENTION The present invention provides high resolution IF-plane scanning +i! +i image reading''
It is an object of the present invention to construct a one-plane scanning optical device that can be realized simply and compactly, and can be easily converted into color.

Structure of the Invention The present invention provides: - At least two or more light-focusing rod lens arrays having an effective aperture length equivalent to the scanning line width; - The scanning line width is divided into n and electronically scanned by n. By means of a plane scanning optical device having two one-dimensional linear image sensor arrays, each image sensor array receives and scans light in small sections of the scanning line length of the original screen so as not to overlap with each other. 211 Achieve your purpose.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In the present invention, instead of the normal lens shown in FIGS. 1 and 2,
A distributed refractive index Rott lens as shown in FIG. 3 is used.

This is known as a light-focusing glass that has a distribution in which the refractive index of the glass is high at the center of the lot 301 and decreases parabolically toward the periphery, as shown in the same figure (al).

When such a glass is cut into a cylinder of an appropriate length and used, it exhibits an imaging effect as a rod-like rod lens as shown in Fig. The same size image 302 of the original picture 3o○ is located at the position of
Tie. This distributed index rod lens can obtain various focal lengths depending on the length of the lot, and the diameter can be made small. It is easy to use a rod lens array 301 of J) (
Compared to the case of using an optical lens, it can be realized in a smaller size and at a lower cost with less lateral bending, so it is used as a scanning optical system in a facsimile transmitter or as an imaging optical system in a copying machine.

The present invention utilizes the above rod lens array to realize a high-resolution image reading Jfl scanning optical system.
The figure shows the screen (3゜401, which is an example of this configuration).
-1 and 401-2 are long rod lens arrays with an effective length n equal to the scanning width of the original image, and are parallel to the scanning line 400 and are inclined by an angle θ to force 4 with respect to the perpendicular to the original image 406. , and projects a scanning line 400 in each direction to connect images 402-1 and 402-2. Long rod array 4
01 is generally provided in m pieces (m is plural). 403-1
and 403-2 are a COD array sensor group arranged so that the light receiving direction matches the images 402-1 and 402-2, and each sensor 403-1 and 403-2 corresponds to the linear scanning line image. It receives light by dividing it into sections alternately.

The original screen 406 is illuminated by a light source not shown in FIG. 4, such as a straight tube fluorescent lamp as shown in FIG. Each COD array sensor 403-1.4Q3-2 is
A section of length LA obtained by dividing the scanning width into n equal parts is shared, and in this embodiment, a case where n=4 is illustrated. Here each COD
Since the element length e of the array sensor 403-1 and 403-2 is longer than the effective length of the light receiving surface, l>L/n, each L/n section is connected to the COD array sensor group 403 as shown in the figure.
-1 and 403-2 alternately share and receive light.

That is, among the n-divided sections, for example, the CCD array sensor 403-1 is assigned to the odd-numbered sections, and the CCD array sensor 403-2 is assigned to the even-numbered sections. A scanning signal can be obtained.

When there are n rod lens arrays and n CCD arrays, one CCD array only needs to receive 1/mn of the scanning line length. '' In the configuration of the invention (rL, ``] Rad lens arrays 4011 and 401-21, the image of 19400 is scanned at a magnification of 1 by the CCD array sensor 403-1, 4o3.
1, 1- Therefore, the resolution (dl, COD array sensor 40
The minute angle i of Cl-1,403-2 can be made almost equal to positive,
For example, between the elementary J' and the pinots 4 It m.

If a CCD with 2048 elements is used, L=23 with n-8
0M(A 4'l'l,l) can be decomposed into 16,384 pixels. Actually, the rod lens array 401-1°4
Since the N power of 01-2 is inferior to the pitch between elements of CCD, the overall resolution is
1-2, but even if this 711 is considered, it is easy to obtain a high resolution of approximately 50 μm. This "high-resolution C2" corresponds to, for example, mechanical scanning for electronic plate making in printing, and has the advantage of being able to secure a sufficient scanning line length and being able to achieve solid-state plane scanning. .

FIG. 5(fL), (b+uThis is an example in which the configuration shown in FIG. 4 is applied to reading a color original image.6oO
9501-1,5CM-2,503-1,503-2
are respectively scan lines 400. of FIG. Rod lens array 401-1, 401-2 ICCD array sensor 403-
1.403-2.

604 is a straight tube type illumination light source, and in the (2L) configuration, a cylindrical three-color separation filter 505 surrounds one light source.
is covered, and the filters are red (R) and green (G).

=tB+ is divided equally on the circumference, and the position is switched by rotation, and the scanning line immediately below is illuminated with R, G, or B filter color light. Filter switching is performed line-sequentially for each scan, or field-sequentially for each screen scan. On the other hand, in the configuration shown in FIG. 6(b), three illumination light sources 504 are used, each is covered with R, G, and B color filters 605-1.505-2.505-3, and only one of them is used. Color separation is performed by selectively lighting up the . If a fluorescent lamp is used as a light source, it can be electrically switched at high speed, so a line sequential method in which color selection is performed for each scan can be used satisfactorily.

FIG. 6 shows yet another embodiment, including a rod lens array 601 corresponding to R, C, B, a color filter 605,
Two sets of CCD array sensors 603 are arranged radially symmetrically, and three color signals are read simultaneously in parallel. In this case, the illumination light source may be white; a reflective original is illuminated by an illumination light source 604, and a transparent original is illuminated by illumination light 11jj 606 placed on the back side.

Effects of the Invention As described above, the present invention is based on the original i+! A plurality of scanning line images are formed by a plurality of self-focusing rod lens arrays having an effective aperture width equivalent to the scanning line length on +i +r+i,
A plane scanning optical device in which a plurality of one-dimensional image sensor arrays are arranged spaced apart on each scanning line image, and each image sensor array divides the scanning line image and receives and scans the light.
The linear image of the original screen can be divided into two parts by multiple C, P image sensor arrays, and can be projected at a 1:1 ratio. There is no need for individual position adjustments, and high resolution can be achieved in a compact, simple, and inexpensive manner. Rod lens arrays can easily be made long enough to accommodate large paper sizes, and can ensure high resolution down to the pitch between COD elements regardless of the screen size, and can be used for mechanical drawings and semiconductors that require high precision. Effective for reading mask drawings, etc.

In addition, it is easy to convert to color, and can also be used as a film scanner for plate making and medical applications, which were conventionally handled with mechanical scanners, especially for color photographic originals.

[Brief explanation of the drawing]

Figure 1 is a basic configuration diagram of a conventional solid-state plane scanning optical system using a single lens, and Figure 2 is a solid-state plane scanning optical system that uses multiple single lenses and multiple image sensors to read drawings with a large scanning line width. Conceptual diagram showing a conventional example of a plane scanning optical system, Fig. 3
+ to (C) are explanatory diagrams of the light-focusing rod lens and rod lens array used in the present invention, FIG. 4 is a perspective view showing an embodiment of the plane scanning optical device according to the present invention, and FIG.
Figures f2L), (b) and Figure 6 are side views showing other embodiments of the plane scanning optical device according to the present invention. 400.500.600...Scanning line, 4011. 4
01-2, 501-1. 501-2,601...
・・Rod lens array, 402-1.402-2 ・
...Statue, 403-1.403-2.603-1. 503-2, e()3..., QcD7v processor, 406°...manuscript, 504.604.606, illumination light source, 605,505-1.605-2.605...
・Color filter. Name of agent: Patent attorney Toshio Nakao and one other person, 111, -3 Figure (α) (b) 30/

Claims (3)

[Claims] (1) One scanning line on the original screen is imaged and projected as m scanning line images by m self-focusing elongated rod lens arrays having an effective aperture width equivalent to the scanning line length. , n one-dimensional image sensor arrays are arranged in a row at equal intervals on each of these m scanning line images, and each image sensor array has a length of one scanning line of the original screen. 1. A plane scanning optical device characterized by receiving and scanning light in divided sections of /mn. (2) The m long rod lens arrays are arranged such that the optical axes of each rod lens intersect in a line on the scanning line of the original screen, and are tilted at appropriate angles to each other with respect to the original screen. A plane scanning optical device according to claim 1, characterized in that: (3) The plane scanning optical device according to claim 1, wherein the scanning line on the original screen and the image of the m scanning lines projected are the same size. (The plane scanning optical device according to claim 1, wherein the 411-dimensional image/sensor array is a solid-state COD element.