JPH0593968A - Illuminator - Google Patents

Abstract

PURPOSE:To effectively use a luminous flux. CONSTITUTION:This illuminator is provided with a bar-like light source 2, a first cylindrical aspherical mirror 3 making the luminous flux A of the light source 2 parallel, and leading it to an original surface 1, in parallel with the light source 2, a first cylindrical concave mirror 13 reflecting the luminous flux A of the light source 2 nonparallel with the light reflected by the aspherical mirror 3, at a position where the luminous flux A does not go to the aspherical mirror 3, and a second plane reflecting mirror 14 reflecting the light reflected by the concave mirror 13 parallel with the light reflected by the aspherical mirror 3 and leading it to the original surface 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lighting device having a fixed light source, which is applied to a copying machine, an image reader and the like.

[0002]

2. Description of the Related Art A conventional illumination device of this type has a point-shaped light source and a rotationally symmetric parabolic mirror (reflecting means) for reflecting and collimating the light flux of the point-shaped light source (US Pat. No. 29017). Then, the collimated light flux is reflected in a slit shape by the reflecting means that further moves, and is guided to a predetermined illumination area.

[0003]

However, in the above conventional example, since the parabolic mirror is rotationally symmetric, the parabolic mirror becomes large in the width direction in order to effectively use the light flux of the light source in the width direction. was there.

An object of the present invention is to solve the above problems, and an object thereof is to provide an illuminating device which can efficiently guide the light flux of a light source to an illuminating area.

[0005]

In order to achieve the above object, the present invention provides a rod-shaped light source, and first reflection means for collimating a light flux of the light source and guiding it to an illumination area is provided in parallel with the light source.
Second reflecting means for reflecting the luminous flux of the light source in a direction not parallel to the reflected light of the first reflecting means is provided at a position where the luminous flux of the light source does not face the first reflecting means, and the reflected light of the second reflecting means is provided. The third reflecting means is provided to reflect the light parallel to the reflected light of the first reflecting means and guide it to the illumination area.

Further, the second reflecting means is provided outside the reflected light flux of the first reflecting means, and the third reflecting means is provided at a position facing the first reflecting means with the light source interposed therebetween.

Further, the second reflecting means is provided at a position facing the first reflecting means while sandwiching the light source, and the third reflecting means is provided outside the light flux of the first reflecting means.

[0008]

In the present invention based on the above construction, the light flux from the light source is reflected by the first reflecting means to be parallelized and guided to the illumination area. In addition, the luminous flux not directed to the first reflecting means is
The light is reflected by the second reflecting means and is guided to the illumination area through the third reflecting means.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. In the figure, 1 is a document surface of a copying machine, 2 is a rod-shaped light source having a plurality of discretely arranged light emitting portions, and the light source 2 is parallel to the document surface 1. 3 is the lateral direction diverging from the light source 2 (Fig. 2
A first cylindrical aspherical mirror as a first reflecting means for reflecting the light flux A component (A) in the middle and up and down directions substantially parallel to the original surface 1 is divided into an upper piece 3a and a lower piece 3b. Reference numeral 12 denotes a first cylindrical concave mirror provided across the light source 2 at a position facing the cylindrical aspherical mirror 3, and returns a light beam directly diverging to the document surface side to the light source 2. Four
Reference characters a and 4b are a pair of first and lower parts that are provided below the document surface 1 so as to face each other.
The plane reflection mirror of (1) reflects the luminous flux component in the longitudinal direction of the rod-shaped light source 2 diverging from the light source 2 to the effective area of the document surface illumination.

Reference numeral 5 denotes a second cylindrical concave mirror that substantially converges the illumination light beam on the original surface 1 and moves in parallel along the original surface 1. Reference numerals 6, 7 and 8 denote exposure first, second and third reflection mirrors provided in parallel with the document surface 1, reference numeral 9 is an exposure image forming lens, reference numeral 10 is an exposure fourth reflection mirror, and reference numeral 11 is a photosensitive drum. is there.

In the figure, a light source 2, a first cylindrical aspherical mirror 3, and a first cylindrical concave mirror 1 are shown.
2, the first plane reflecting mirrors 4a and 4b, and the second cylindrical concave mirror 5 constitute an illumination unit, and the second cylindrical concave mirror 5 illuminates the document surface 1 with slits. The reflected light from the document surface 1 is reflected by the exposure first, second and third reflection mirrors 6, 7, 8 and enters the imaging lens 9, and the imaging light by the imaging lens 9 is exposed by the fourth reflection mirror. It is reflected by 10 and is exposed on the photosensitive drum 11.

The scanning of the slit illumination of the document surface 1 is performed by scanning the second cylindrical concave mirror 5 and the exposure first reflecting mirror 6.
Are moved as a unit, and the second and third exposure mirrors for exposure 7 and 8 are moved as a unit to move by half the amount of the second cylindrical concave mirror 8 and the first exposure mirror 6, At 1, the light flux generated from the light source 2 is condensed by the first cylindrical aspherical mirror 3 and the plane reflection mirrors 4a and 4b arranged on both sides of the document surface 1 and travels substantially parallel to the document surface 1. The second cylindrical concave mirror 5 collects the light flux and illuminates the original surface 1 while scanning it. Reference numeral 13 denotes a second cylindrical aspherical mirror as a second reflecting means, which includes an upper piece 3a and a lower piece 3a.
It is provided on the right side between b and b. Reference numeral 14 denotes a second plane reflecting mirror (third reflecting means), which is directly below the second cylindrical aspherical mirror 13. Even if the first cylindrical aspherical mirrors 3a and 3b are aspherical mirrors whose central portions are connected to each other, they can be shielded by the first cylindrical concave mirror 12 that serves to directly shield light and become illumination light. Absent.

Therefore, the light flux leaking from the gap between the first cylindrical aspherical mirrors 3a and 3b is once converted into parallel light in the direction perpendicular to the document surface 1 by the second cylindrical aspherical mirror 13, and then the second light is emitted. It is bent by the plane mirror 14 to form a light beam parallel to the document surface 1. With this configuration, the divergent light can be efficiently picked up from the light source 2 and converted into illumination light. As the light flux width of the light source 2 in the lateral direction increases, the widths of the first flat reflecting mirrors 4a and 4b arranged on both sides of the document surface 1 and the second cylindrical concave mirror 5 for scanning. The width of must be large.

FIG. 2B shows a second embodiment of the present invention. In the figure, reference numeral 15 is a second cylindrical concave mirror for returning the light flux from the light source 2 at the rear center portion to the light source 2.
Reference numeral 6 denotes a second cylindrical concave mirror 1 with a light source 2 in between.
A second cylindrical aspherical mirror serving as a second reflecting means provided to face 5 and a second plane reflecting mirror 17 are located directly below the second cylindrical aspherical mirror 16. In the figure, a second cylindrical aspherical mirror 16 converts a light beam diverging from the light source 2 toward the central portion on the side of the document surface 1 into a parallel light beam in a direction perpendicular to the document surface 1, and uses the first cylindrical aspherical mirrors 3a and 3b. The second plane mirror 17 is arranged at a position where the parallel light flux is not shielded so that the parallel light flux becomes a light flux parallel to the document surface 1.

FIG. 2C shows a third embodiment of the present invention. In the figure, 18 is a second cylindrical aspherical mirror,
It is between the document surface 1 and the light flux A. Reference numeral 19 denotes a second plane mirror, which faces the first cylindrical aspherical mirror 3 across the light source 2. In the figure, a second cylindrical aspherical mirror 18 makes a light beam diverging obliquely upward from the light source 2 on the document surface 1 side into a parallel light beam in a direction perpendicular to the document surface 1, and a parallel light beam from the first cylindrical aspherical mirror 3 is generated. The second plane reflection mirror 19 arranged at a position where the light is not shielded forms a light flux parallel to the document surface 1.

[0016]

Since the present invention is configured as described above, the luminous flux that cannot be reflected by the first reflecting means can be efficiently guided to the illumination area by the second and third reflecting means.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of the present invention.

2A is a front view of the first embodiment, FIG. 2B is a front view of the second embodiment, and FIG. 2C is a front view of the third embodiment.

[Explanation of symbols]

 1 Original Surface 2 Light Source 3 First Cylindrical Aspherical Mirror 13 Second Cylindrical Concave Mirror 14 Second Plane Reflecting Mirror A Luminous Flux

Claims (3)

[Claims] 1. A rod-shaped light source is provided, first reflecting means for collimating the light flux of the light source and guiding it to an illumination region is provided in parallel with the light source, and the light flux of the light source does not face the first reflecting means. ,
An illumination area is provided by providing second reflecting means for reflecting the light flux of the light source in a direction not parallel to the reflected light of the first reflecting means, and reflecting the reflected light of the second reflecting means in parallel with the reflected light of the first reflecting means. An illuminating device, characterized in that a third reflecting means for guiding to is provided. 2. The illuminating device according to claim 1, wherein the second reflecting means is provided outside the reflected light flux of the first reflecting means, and the third reflecting means is provided at a position facing the first reflecting means across the light source. .. 3. The illumination device according to claim 1, wherein the second reflecting means is provided at a position facing the first reflecting means with the light source interposed therebetween, and the third reflecting means is provided outside the light flux of the first reflecting means.