JPS6058770A - Reflective illuminating device of original - Google Patents

Abstract

PURPOSE:To reduce flaws reproduced as output pictures and reproduce a qualitative impression, which is caused by ruggedness peculiar to an original, on the output picture, by irradiating the original with irradiated luminous fluxes from many directions and making it possible to select irradiated luminous fluxes. CONSTITUTION:For the purpose of reducing flaws which are reproduced on the surface of photosensitive materials of a recording drum in accordance with flaws of an original 12 and a transparent plastic sheet put on the original, the original 12 is irradiated through optical fibers 22 from their light projection end faces in many directions because directions of flaws are random. In this case, a rotary slit plate 23 has a round area P held in a rotation angle position just facing a handle part 20, and all light receiving end faces of optical fibers 22 are allowed to receive the irradiated light from a light source part 17, and irradiated luminous fluxes are irradiated to the surface of the original 12 from light projection end faces of optical fibers 22 in, for example, 8 directions different from one another. When the qualitative impression caused by ruggedness peculiar to the original is emphasized and reproduced on the surface of photosensitive materials of the recording drum, the slit plate 23 is turned to select optical fibers 22 which specify the direction of irradiated luminous fluxes.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reflective document illumination device for scanning a document, such as a plate-making scanner.

For example, in a drum-shaped prepress scanner that uses a reflective light source, a document drum on which a document is set is rotated at a constant rotational speed, and a scanning head equipped with a scanning optical system and a photoelectric conversion element is attached to the drum. The document is moved at a relatively constant speed in a direction perpendicular to the direction of rotation, and is scanned so that the entire surface of the document is sequentially covered by the scanning light beam from the document illumination device that constitutes the scanning optical system. After picking up the reflected light from the area and photoelectrically converting it, a predetermined correction process is applied to this electric signal, and the recording light source is appropriately controlled based on the correction signal.
A desired output is produced on the photosensitive material placed on the recording drum.

By the way, if there are scratches on either or both of the document fixed to the document drum and the transparent plastic sheet used to hold and fix the document, this scratch can be corrected using the above-mentioned correction process 5! without being eliminated or reduced by any modification.

This will be reproduced on the photosensitive material surface of the recording drum.

That is, in a conventional reflective document illumination device.

For example, as shown in FIG.
), there is a scratch parallel to the axis X-X of
As shown in FIG. 5, which is a cross-sectional view taken along line 9, light is reflected from the document illumination device to the document α2 (A).

Since the light flux is irradiated from only the two directions (b), the amount of irradiation light on each surface of A, B, C, and D is (
(a) and (b) It is the total amount of light of both luminous fluxes. On the other hand, if the original 02 set on the original drum 0υ has a scratch (to)' in the circumferential direction of the n-th drum OD as shown in Fig. 2, the same scratches as shown in Figs. As shown above, since the direction of irradiation of the light beam from the original illumination device is the same as above, only the two directions (a) and (b), the amount of light irradiated on each side of A and B is (a) and (b) the light amount of both light beams. However, for the 0th plane, it is only the amount of (b) luminous flux.

The only thing on the 0th plane is (a) the amount of light flux.

In this way, in the case of Fig. 1, light beams (a) and (b) are irradiated from two directions on each surface inside the scratch (131), but in the case of Fig. 2, the scratch (131) is Since each surface inside the α field is irradiated with only one of the light beams (a) and (b) from two directions, the amount of reflected light decreases at the scratch αj, and as a result, the amount of reflected light at the scratch αj decreases. will be reproduced as a shadow on the surface of the photosensitive material of the recording drum.

In other words, in conventional reflective document illumination devices,
Since the irradiation direction of the irradiation light beam is limited to two directions,
Manuscript α2. It is a specific method to eliminate or reduce scratches that appear on the photosensitive material surface of the recording drum due to scratches that occur on either or both of the transparent plastic sheets (not shown) that cover the document drum and bring them into close contact with the original drum αυ. It is a painting itself drawn on cloth, which has the problem that it cannot be done without removing scratches in the direction of The request is for the scratches mentioned above (13
1. The purpose is to reproduce the unique unevenness of the weft, warp, or brush touch that corresponds to aai, and for that purpose, we need to reproduce both scratches Q31 and aai.
The surface of the original 121 must be irradiated diagonally from above intersecting the specific direction of the unevenness.

In order to meet the above-mentioned request to eliminate or reduce the reproduction of scratches on the original and/or the adhesive plastic sheet, it is sufficient to irradiate the O2 side of the original from as many directions as possible. If the original is irradiated from multiple directions, it will not be possible to meet the demand for emphasizing the texture of the original.

The present invention solves or reduces the contradictory requirements of the conventional reflective document illumination device for a scanning head, namely, the reproduction of scratches on the document and/or the transparent plastic sheet for pressing the document.

This was done in order to both emphasize the texture of the original, and make it possible for scratches on the original and scratches on the transparent plus sheet overlaid on the original to be erased or greatly reduced in the output image. On the other hand, it is an object of the present invention to provide a reflective document illumination device that can emphasize and reproduce the texture of a document's unique unevenness as an output image, if necessary.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example device according to the present invention will be described below with reference to the drawings. FIG. 7 is a schematic explanatory diagram showing the configuration of this embodiment device.

This device consists of a light source α consisting of a stable halogen lamp, for example, provided at the focal point of a parabolic concave reflector aω.
The pickup lens structure a incorporated in the scanning head, the optical fiber holding part 09 provided at the end of the pickup lens structure α facing the document, and the light emitting end attached to this holding part (191). are each fixed, the light-receiving end is fixed to the handle part (1t), and the light-receiving end surface is aligned with the imaging plane of the condenser lens (2) (in this example, there are 8
The rotary slit plate (2) inserted into the optical path between the optical fiber (2) of the book), the condensing lens (2υ, and the handle part (A))
(to).

As shown in FIG. 8, the pickup lens structure (18 is fixed to the scanning head at a fixed position close to the original (original driver 501 on which 12 is set) with its axis coincident with the radial direction thereof. The reflected light condensing lens (A) is held at a fixed position in the inner cylinder (A) inserted into it.The optical fiber holding part (1) on the outer periphery of the front end
In (G), each of the pickup lenses Ii has an inclination angle of 45° with respect to the axis indicated by 1α.

Equal angular intervals around the axis (in this example, center angle =
Optical fiber insertion tubes (2) are arranged at an angle of 45°), and the light emitting end of the optical fiber (2) is inserted and fixed into each insertion tube (to), and the irradiation light beam is emitted from the end face of each optical fiber (2). As shown in FIG. 11, the scanning spot of the document f12 is obliquely irradiated from eight different directions.

The rotary slit plate (C) inserted into the optical path between the condenser lens (curve) and the bundle part (C) has its rotation angle as shown in the front view (Figure 9) when viewed in the direction of the arrow in Figure 7. Depending on the position, a circular area (P) directly facing the bundle part (4))
, tQl , (IC, (Sl, handle part (4)
The slits (A) are arranged in correspondence with the arrangement of the optical fibers (A) in ) in accordance with the illustrated pattern.

Therefore, for example, if the slit plate is held at a rotational angle position where the circular area (P) directly faces the bundle part head, the optical fiber (A) will receive the light beam from the light source part α on its light receiving end face. The illuminating light beam is transmitted from the light emitting end surface to the document (from eight different directions).
When irradiating 12 surfaces respectively, and when the 9 circular areas @) are directly facing the handle part (a), the optical fiber will direct the irradiation light flux from 5 different directions onto the document (2) surface. Each will be irradiated.

Next, the operation of this device will be explained.

(i) To erase or reduce scratches that are reproduced on the photosensitive material surface of the recording drum due to scratches on the original or the transparent plastic sheet overlaid on the original.Generally, scratches that occur on the surface of the original or the transparent plastic sheet overlaid on the original are handled while handling the original. Since the direction of the scratches is random with no directionality, the direction of the irradiation light beam that is irradiated obliquely from the light emitting end surface of the optical fiber (a) to the document (12) is made from as many directions as possible. It is clear from the above that this is desirable, and test results show that scratches can be erased on the surface of the photosensitive material in 6 to 8 directions that are practically possible. (to) at a rotational angle position where its circular area (P) directly faces the handle part (A), the irradiated light from the light source part Q71 is received by any light receiving end surface of the optical fiber (2), and each optical fiber Co., Ltd.'s light emitting end face illuminates the original O2 from eight different directions.
Irradiate the surface. If you do it like this.

Regardless of the direction of scratches on the document and the transparent plastic sheet that overlaps them, it is possible to eliminate or make the scratches on the pickup side less conspicuous by reproducing them in the output image. This eliminates the need to repair scratches.

(ii) When emphatically reproducing the unique uneven texture of an original on the photosensitive material surface of a recording drum: For example, if the original is a painting drawn on a fabric woven from warp and weft threads, the texture of this fabric is reproduced on the photosensitive material surface. In order to reproduce this with emphasis, it is sufficient to irradiate the document surface with the irradiation light beam from a direction that intersects both the warp and weft, which are perpendicular to each other, at an angle as large as possible.

For example, when a fabric manuscript is set on the manuscript drum Ql) with the warp aligned in the circumferential direction and the weft aligned in the direction parallel to its axis, one of the eight optical fibers (supports) , as shown in Figure 11.
(Four beams are selected to irradiate the surface of the document (2) obliquely with the irradiation light beam from each direction of L (7). For this purpose, the slit plate (2) is adjusted so that its rotation angle position is in the circular area (
6') and the bundle part (A), rotate it by 90° clockwise from the rotation angle position shown in FIG. 9. In this way, the above-mentioned (e), (e), ()), t' can be achieved by using the pore slits in the 9 circular areas (ri).
The irradiation light is transmitted only to the four optical fibers (2) that irradiate the irradiation light flux in each direction of F3, and the unique unevenness formed by the warp and weft of the fabric is emphasized and reproduced in the output image.

In addition, when selecting the optical fiber that specifies the direction of the irradiation light beam mentioned above, instead of using the rotary slit plate □□□ shown in Fig. 7, another irradiation light selection means may be used. You can also do it. Figure 10 schematically shows the configuration of another irradiation light selection means, which consists of eight optical fibers.
at the light receiving end.

A light source unit consisting of a halogen lamp 0611 reflective four-sided GA (151) and a lens (211) are connected in the optical path, and the 8 halogen lamps (161) are made by an optical fiber that irradiates the irradiation light beam from a desired direction. It selectively lights up the ones that correspond to it.

As a modification of this other means, each of the optical fibers (a) may be provided with a mechanical optical switching mechanism, and the direction of the irradiation light beam may be selected by operating the optical selector switch.

If the manuscript is a painting drawn on cloth (canvas) and the touch of the brush is to be reproduced in the output image, the direction of the touch is clumsy, so it is impossible to emphasize any of them. However, in this device, it is possible to emphasize two or three specific directions to a considerable extent by selectively lighting the halogen lamp Q[e described above or selectively switching the optical fiber area.

In the above description, the case of a reflective document illumination device for a drum-shaped plate-making scanner has been explained, but it should be noted that the present invention can be effectively applied to not only color scanners and black-and-white scanners, but also flat scanning scanners. Not even.

As is clear from the above description, in the reflective document illumination device according to the present invention, originals 1'1jli (i-9 less than In both cases, the original is irradiated with light beams from three or more directions, for example, from eight directions.
If there are scratches in random directions on either or both sides of the transparent plastic sheet, it is possible to prevent the scratches from being reproduced as an output image by irradiating the irradiation beam from as many directions as possible, or at least It is possible to reduce the flaws inconspicuously and omit correction of the flaws in the output image. In this device, the irradiation light selection means allows only the desired direction of irradiation light to be selected from among the irradiation light beams in multiple directions, so that the texture resulting from the unique unevenness of the original can be reproduced in the output image. If this is necessary, the texture can be reproduced by selecting the irradiation direction by the irradiation light selection means so as to emphasize the unevenness in a specific direction.

[Brief explanation of drawings]

FIGS. 1 and 2 are perspective views showing a document with scratches in a specific direction set on a document drum, and FIG. Figure 4 shows the 1. Figures 5 and 6 are partial perspective views that extract and enlarge the scratched parts of the original in both Figures 2 and 3 and show the irradiation light flux. Figures 5 and 6 show the axis of the original drum in Figures 3 and 4 FIG. 7 is an explanatory diagram showing the configuration of the main parts of the embodiment device according to the present invention, FIG. 8 is a side sectional view of the pickup lens structure incorporated in the scanning head, Figure 9 is a front view of the rotary sleeve ■ plate.
FIG. 10 is a schematic explanatory diagram showing the configuration of another embodiment of the device according to the present invention, and FIG. 11 is a perspective view showing the arrangement of the light emitting end of the optical fiber. OD...Original drum (171...Light source section OD...Pickup lens structure...
...Optical fiber 1)-

Claims (1)

[Claims] 1. A scanner that irradiates light onto a scanned document from the side of a scanning head that scans the document at predetermined intervals, and causes reflected light from the document to enter the scanning head. In the reflective document illumination device, a light emitting end of a light transmitting means for optically transmitting light from a light source is disposed around the scanning head so as to face the scanning spot from at least three directions, 1. A reflective document illuminating device, comprising: a selection device for selecting conduction of light to the device, and the document is illuminated from a desired irradiation direction by selection of the selection device. 2. A reflective document illumination device according to claim 1, wherein the light transmission means is an optical fiber. 3. A reflective document illumination device according to claim 2, wherein each input end of the optical fiber is focused at a position facing a single light source. 4. The selection means for selecting conduction of light to the light transmission means,
It consists of a substrate that is interposed between each input end of the optical fiber and the light source by selectively forming an opening corresponding to a desired direction of the light emitting end of the light transmission means, and selectively replacing this substrate. By. A reflective document illumination device according to any one of claims 1 to 3, which irradiates the document from a desired irradiation direction. 5. The selection means for selecting the conduction of light to the light transmission means also consists of a changeover switch that selectively turns on the light sources facing the input ends of the optical fibers in each direction arranged around the scanning head, and this changeover switch 3. A reflective document illumination device according to claim 1, wherein the document is irradiated from a desired direction by switching.