JPS6059860A - Reflected type original illuminating device - Google Patents

Abstract

PURPOSE:To prevent error of density by making the illuminance of a reflected light from each original almost coincident and arranging the balance of high light in scanning and recording the original formed by a simple scrap work. CONSTITUTION:The original set to an original drum is irradiated obliquely by irradiated luminous flux from a bundle fiber 21 whose light projection end is held to an optical fiber holder part 24 provided at an outer circumference part of a lens barrel 25 holding a pickup lens to a prescribed position. Thus, the simple scrap original formed by overlapping other original pieces cut off for the required part and adhered on the original is reproduced on a photosensitive material of a recording drum while keeping the specific contrast of each scrap original piece.

Description

Detailed Description of the Invention For example, in a drum-shaped plate-making color scanner using a reflective light source, a document drum on which a color document is set is rotated at a constant rotational speed, and a scanning optical A scanning head equipped with a system and a photoelectric conversion element is moved at a relatively constant speed in a direction orthogonal to the rotational direction of the drum, and the original is illuminated by a scanning light beam from an original illumination device that constitutes a scanning optical system. The entire surface is sequentially scanned, and the reflected light from a minute area of the document is picked up through a reflective light pickup lens and photoelectrically converted. This electrical signal is then subjected to a predetermined correction process, and this corrected signal is generated. By appropriately controlling the recording light source based on this, a desired output is obtained on the photosensitive material placed on the recording drum.

The combination of images (
Traditionally, when performing so-called collections, it was done manually.
In general, each image is pasted, corrected, etc., but such work requires a considerable amount of energy and time. Therefore, the following method may be used to simplify the complicated compilation work. That is, by cutting out only the necessary portions of the document based on a predetermined layout and pasting them onto a mount or other document, the above-mentioned steps can be omitted at least partially. Created by this simplified collection process: IL pasted manuscript α〃 as the first
As shown in the figure, the image is scanned by setting it on a document drum @ as a reflective document.

In normal image scanning, the shading is reproduced in the output 1LII image according to the shading of the document surface, but in the manuscript collected by the above-mentioned simplified method, two stages are printed on the mount or other manuscript. A method was used in which the manuscripts were stacked in six columns,
For example, as shown in Figure 2, 6, original ic1 i a),
(111)), (110) are stacked in six stages, and assuming that these originals all have the same reflectance, the originals (11a), (111)), (11
(Brightness La%Lb on each surface.

・W Lc=”T−W. In particular, W is fixed at a fixed position, n is the irradiation beam per unit area of the irradiation flux from the light source, and t is the original thickness of the original (1i a), (111
1), the thickness is (110). Therefore, as the document moves away from the light source, the brightness of the document surface decreases, and naturally the amount of light reflected from that document surface also decreases, and this slight difference in distance from the light source is reproduced as a density difference in the output image. becomes. In other words, manuscript (11a) is 7% darker.
Original (111:Ihi) is slightly dark, original (11C; bright and resolved.

In FIG. 3, a highly stable halogen lamp QO is fixed to match the focal point of a parabolic concave reflector aφ, and the irradiated light from the halogen lamp a is directed to the reflector 0 [? The original α1 set on the original drum (2) is reflected by
) so that the surface is irradiated from an oblique direction as a beam of light,
This is a schematic illustration of a conventional reflective document illumination device in which a condenser lens αη is fixed at a fixed position.

In this conventional reflective document illumination device, the light source lamp is arranged in the periphery of the pickup lens to irradiate the scanning spot from an oblique direction. The projected light spot generated on a plane perpendicular to the optical axis forms a circular zero barrel as shown in the figure,
As shown in the figure, the illuminance distribution state at the circular spot 0→ is formed into a single mountain shape, that is, a curve OO resembling a unimodal Gaussian distribution. The irradiation light beam irradiated onto the original 09 surface from an oblique direction as described above is reflected by the reflected original 0η, but this reflected light is directed to a surface parallel to the plane perpendicular to the y-axis (original Q) on the y-axis. FIG. 5 shows how the illumination intensity changes depending on the Qt/C on the vertical plane when the light is received at . In Figure 5, + on the y-axis
The direction indicates the direction toward the document drum (2), and one direction indicates the direction away from the document drum (6).

Therefore, as shown in Figure 2, the manuscript (11a), (1l
b), (11C) superimposed: i and original tram (2
), the illuminance of the reflected light in the y-axis direction from each document surface is AlB, C,
From Figure 5, the manuscripts (11a), (111)), (11
It can be seen that even if the overall position of Q) is slightly moved in any of the above directions along the y-axis, the order of the illuminance of the reflected light of t(ljfl,) does not change.

From this, the position of the irradiation light source may be slightly moved and adjusted (2) The density corresponding to the originals (11a), (1l b), and (11Q) in the output image due to the slight difference in distance from the light source will vary. Correcting the reproduction of differences has proven difficult in conventional reflective document illuminators.

However, instead of directly irradiating the irradiation light beam from the condensing lens αη in the document illumination device, an optical fiber (for example, 50 μm in diameter ) When irradiating the irradiation light beam onto the original (11) from an oblique direction through a bundle fiber made of about 400 fibers &]),
A projected light spot generated on a plane perpendicular to the optical axis at the intersection of the optical axis and the Oη plane of the original forms a donut-shaped concentric circle as shown in the figure, with a small portion in the center slightly darkened.

(The illuminance distribution state at Ij is a bimodal distribution as shown by curve d.The occurrence of such a donut-shaped light projection spot has been experimentally recognized,
This is especially noticeable in pigeon lofts that use bundled optical fibers. The reason for this is thought to be that when the incident light to the optical fiber input end has an angle with respect to the inner wall of the optical fiber, the height becomes high at the boundary between the core and the clad in the optical fiber.

In this case, the illuminance of the reflected light on a plane perpendicular to the y-axis will draw a curve as shown in Figure 6 depending on the position of that plane, and the illuminance of the reflected light will draw a curve as shown in Figure 6. are set on the document drum Q4 in an overlapping manner as shown in Fig. 2, so that y from the document surface of n is
The illuminances of reflected light in the axial direction, B, and C, are approximately the same as shown in the figure. By using the bundle fiber C'l) in the reflective document illumination device, the originals 1 (tla), (11b), (11Q) in the output image can be
This means suppressing the reproduction of density differences that would otherwise occur in response to n.

Furthermore, when the entire position of the originals (11a), (1lb), and (11C) is slightly moved in one direction along the y-axis as shown in FIG. The relationship between the illuminances A, , B, and C is A>B>C, and in the case of Fig. 5, A Furthermore, when the overall position of the originals (11a), (1l b), and (11C) is slightly moved in ten directions along the y-axis as shown in FIG. The relationship between illuminance A1B%C is A (B (C) and the order of illuminance is somewhat reversed from that in FIG. 7.

In FIGS. 7 and 8, for convenience of explanation, the original ";A(
11a), (11'0), and (11C), the illuminance of the reflected light in the y-axis direction when the teno position is slightly shifted in one direction or ten directions along the y-axis is Although we have talked about the changing phenomenon, the same phenomenon can be observed by fixing the position of the pickup lens In that receives the reflected light beam at a predetermined distance from the document surface, and changing the position of the light emitting end surface of the bundle fiber 〇1). It is clear that this can also be caused by slightly moving back and forth along the optical axis with respect to the document surface.

By the way, the original (i 1b)' is on the top surface of the mount (11a).
= Jy, draft 0.1), the highlight part of the original (11111) has almost the same reflectance as the normal mount (11a), so the halftone scanner f (and the conventional When using a reflective original illumination system, as explained in Fig. 2, the output image of the recording drum has halftone dots with a larger area on the backing paper, and the backing paper portion of the output image is distorted. Although it is necessary to perform opaque work to remove and correct the halftone dots, the bundle fiber eυ mentioned above is used as the light source, and its light emitting end face is attached to the surface of the original (111) attached to the mount (i 1 a). If it is possible to move away from the surface, the same phenomenon as explained in FIG. 7 will occur, and the amount of reflected light will be reversed to be greater from the mount surface, and the opaque operation described above can be omitted.

The main purpose of this invention is to prevent density errors in output images due to the thickness of overlapping originals when scanning and recording originals created by the above-mentioned simple collection process, and to ensure appropriate yield. Another object of the present invention is to provide a reflective manuscript illumination device that can obtain an output image of The present invention aims to provide a reflective document illumination device that can prevent the output of unnecessary halftone dots on the mount portion (() and omit the opaque work when performing the halftone work.

Embodiments of a reflective document illuminating device according to the present invention will be described below with reference to the drawings.

FIG. 9 is a schematic explanatory diagram showing the configuration of this embodiment.

This device consists of a light source section (1) consisting of a condenser lens (αη) that condenses and irradiates reflected light from a stable halogen lamp (for example), which is installed at the focal point of a parabolic concave reflector (1 [il). 2), an optical fiber holder (F) provided at the end of the pickup lens (C) facing the document; The light end is 1. Fixed nl,
The light-receiving end is fixed to the bundle part (c), and the light-receiving end face is made to coincide with the imaging plane of the condensing lens α force. There is.

The bundle fiber Cυ is formed by bundling approximately 400 optical fibers (with a diameter of 5 mm) that transmit light while reflecting it at the interface between the core and cladding, and the diameter at the light emitting end is approximately 1 mm. It is 3111.

As shown in FIG. 10, the pickup lens section (c) has its axis coincident with the radial direction of the document drum α group on which the document (11a and the like) is set, and has a condensing lens for reflected light ( It is fixed to the scanning head by the horizontal lens tube (c) that holds the piccoa amplifier lens (a), and the optical fiber holding part (f) is engaged with this lens structure so that it can slide freely in the direction of the arrow. -L% The engagement position can be fixed by tightening the push screw (1).

The optical fiber holding part (incorporated) has an inclination angle of 45" with respect to the axis of the horizontal barrel of the optical fiber lens, and is spaced at equal angular intervals around the axis (in this example, the center angle = 45 degrees). ) is installed in the optical fiber insertion tube (a), and the optical fiber (al) is installed in the insertion tube (a).
When the light emitting end is inserted and fixed, the name bundle fiber 6!
As shown in FIG. 11, the irradiating light beam from the end face of η obliquely irradiates the scanning spot of the original (11a) from eight different directions.

Next, the operation of this device will be explained.

(1) If you want to reproduce the unique brightness and darkness of each original as an output image for a simplified edition manuscript in which a separate original with only the necessary parts cut out and pasted on top of the original is to be used as an output image, bundle The light emitting end surface of the fiber Q force is the fourth
Fix the optical fiber holding part (c) to the bind-up lens horizontal tube (c) so that it occupies the same position as shown in the figure.
The illuminance of the reflected light from each original (11&), (111)), and (110) should be almost the same, and each original (11&)
, (111)), and (11C), the balance of the highlights may be made the same. The reason why the n\lights of each document are aligned in a well-balanced manner by doing this has already been explained, so the explanation will be omitted.

←) For the original pasted on the mount, highlight the mount and opaque the output image obtained by the shading scanner. It is only necessary to reverse the distance between the illumination on the mount which is away from the light emitting end surface of η by the thickness of the document, and the light on the original which is closer to the light emitting end surface than the mount. The same phenomenon as shown in FIG. 7 can be achieved by moving the light emitting end surface of the nozzle fiber Q) farther away from the document drum Q2 by, for example, about 1 to 2 yen from the position shown in FIG. 4. To avoid this, in Fig. 10, loosen the set screw (c) and slide the optical fiber holding part (c) to the left with respect to the lens horizontal tube (c) by about 1 to 2 mW. Tighten the set screw (1) again to secure it.

In this way, in contrast to the difference in distance between the original and the mount from the same reflecting and projecting end surface, the difference in distance can be reversed as shown in Fig. 7, and the highlight of the mount can be emphasized in the output image. Opaque work can be omitted.

As is clear from the above description, 1. In the reflective document illuminating device according to the present invention, the document completely set on the document drum is illuminated by an optical fiber provided on the outer periphery of the lens horizontal tube that holds the pickup lens in a predetermined position. Since the illumination beam from the bundle fiber whose light emitting end is held in the holder is used to irradiate from an oblique direction, it is possible to simplify the method by pasting another original with only the necessary parts cut out on top of the original. Since the edge position of the recording drum can be changed with respect to the original surface, it is possible to maintain the unique brightness and darkness of each original in a collection of manuscripts. On the other hand, it is possible to emphasize the highlights of the mount, and, for example, it is possible to omit filling in the halftone dots of a recorded photograph, which is selectively selected by a halftone scanner, that is, an opaque operation.

In the above description, a drum-shaped scanner has been described for convenience, but the present invention can be applied not only to color scanners and black-and-white scanners, but also to plane scanning scanners, and the above-mentioned effects are the same. It is played on

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a document drum with pasted originals set therein, and FIG. 2 is a schematic explanatory diagram showing a state in which irradiation light is irradiated onto originals that have been overlapped and pasted. FIG. 6 is an explanatory diagram showing the irradiation state on the document surface by a conventional reflective document illumination device, a graph showing the system, FIGS. 6, 7, and 8 are graphs showing this, and FIG. 9 is an example. FIG. 10 is an explanatory view showing the configuration of the main parts of the apparatus, and is a perspective view showing the apparatus after being assembled for scanning. (11), (11a), (111)), (11C) −
...Reflection original, α'4...Document drum, (21)...~Bundle fiber, (A)...Light source section, ■...Pickup lens section, Q, ■--Optical fiber holding section, (c)...Big up Renoz horizontal tube. Fig. 1 Fig. 3 -→υ axis is i 2nd @ Fig. 4 -→ BiΦyu') 5fn+

Claims (1)

[Scope of Claims] 1. A scanner in which light is obliquely irradiated onto a scanned document from the periphery of a scanning head that scans the document at predetermined intervals, and reflected light from the document is incident on the scanning head. In a reflective document illumination device, the light emitting end of a source fiber that optically transmits light from a light source is located at the river side of the scanning head, and the light emitting end of this optical fiber is positioned on the side of the document surface. A reflective document illumination device characterized in that it is movable in a vertical direction. 2. A reflective document illuminating device according to claim 1, wherein the light emitting end of the optical fiber is directed toward the scanning spot from at least 20,000 yen at the end of the scanning head. 3. The reflection according to claim 1 or 2, wherein the optical fiber irradiates light with an illuminance distribution in which the illuminance in the intermediate region is relatively high with respect to the center and edge of the optical axis. Shape manuscript illumination device.