JPH0328839A - Illuminator - Google Patents

Abstract

PURPOSE:To prevent the occurrence of the irregularities of ripple on a position to be irradiated on an original surface in the case that an illuminator is approached near the original surface by disposing a means for diffusing light from a light emitting part in a longitudinal direction of a linear light source. CONSTITUTION:The illuminator 1 is constituted of a straight tube lamp (a linear light source) 2 and a reflection mirror shade 3 functioning as a reflecting means for condensing the light on an original S, and the lamp 2 is constituted of a slender straight glass tube (a tubular member) 4 and a filament 5 constituting segments A1-A5 as the light emitting part 1. And the reflection mirror shade 3 is disposed nearly in parallel with the lamp 2, and projecting parts(diffusing means) 3a-3b whose sections are nearly arcuate are disposed at the positions corresponding to the segments A1-A5 so that the light from the segments A1-A5 may be diffused in the longitudinal direction of the lamp 2. Thus, even if a distance D is short, the irregularities of ripple on the positions to be irradiated corresponding to the segments A1-A5 and the positions corresponding to the distance between the position on an L-R and the segments A1-A5 are reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is applicable to, for example, a copying machine. Image scanner. The present invention relates to an illumination device for illuminating a document in an image reading unit of a facsimile machine, and particularly to one using a linear light source.

[Prior Art] Conventionally, there are illumination devices as shown in FIGS. 6 and 7 that are equipped with a linear light source for illuminating a document in an image reading section of a copying machine or the like.

This turns on the straight tube lamp +02 as a linear light source of the illumination device 101, and focuses the light from the straight tube lamp +02 on the surface of the document S using the reflecting mirror 103 as a reflecting means. It is for illumination. Here, the straight tube lamp 102 includes an elongated glass straight tube 104, and a plurality of filament winding portions (hereinafter referred to as segments) al, a2, a3, a4, as light emitting portions within the tube 104.
It consists of a filament 105 having a5,
The lighting of this straight tube lamp 102 is caused by the filament 105
By energizing each segment at, a2, a
Each of the points 3, a4, and a5 emits light, and the whole becomes a linear light source. As shown in FIG. 8, from the straight pipe lamp 102, this straight pipe lamp 10
As shown in FIG. 9(a), the light amount distribution of the light irradiated to the irradiated position L-H on the surface of the original S is as shown in FIG. ,a
2, a3, a4, and a5 are combined to form a total light intensity distribution E, which provides uniform illumination at the irradiated position L-R. [Problems to be Solved by the Invention] However, In the above-described conventional example, the straight tube lamp 102 used as a light source has segments al on the filament 105 arranged in the longitudinal direction of the straight tube lamp 102.
, a2, a3, a4, and a5, and the other parts do not emit light. Therefore, if the distance between the straight tube lamp 102 and the document S surface is shortened, the irradiated position L-R on the document S surface As shown in Figure 9(b), the total light intensity distribution E at
Therefore, in order to make the total light amount distribution E at the irradiated position LR on the surface of the original S uniform as shown in FIG. 9(a), it is necessary to It was necessary to maintain a certain distance from the surface. That is, since the illuminance of light is inversely proportional to the square of the distance according to the inverse square law, increasing the distance between the straight tube lamp 102 and the document S side increases the rate of light loss in illumination. In the conventional example, the light from the light source could not be used effectively.

In addition, increasing the distance between the straight tube lamp 102 and the document S surface requires an increase in the size of the illumination system, which hinders miniaturization of the apparatus.

The present invention has been made to solve the problems of the prior art described above, and its purpose is to reduce the size of the device and eliminate unevenness in the light intensity distribution of the light emitted from the lighting device. ．． [Means for Solving the Problems] In order to achieve the above object, the present invention includes a linear light source in which a plurality of light emitting parts are arranged within a tubular member, and a linear light source arranged substantially parallel to the linear light source. In the illumination device, the light from the light emitting part is reflected from the linear light source at a position on the reflecting means corresponding to the position of the light emitting part. A diffusion means was provided to diffuse the particles in the longitudinal direction. [Function] In the present invention having the above configuration, the light from the light emitting section is directed to the position on the reflecting means provided substantially parallel to the linear light source, which corresponds to the position of the light emitting section. By providing a diffusion means that diffuses in the longitudinal direction of the shaped light source, there is no risk of unevenness in the light intensity distribution at the irradiated position on the document surface even when the illumination device is brought close to the document surface. [Embodiment] A first embodiment of the present invention is shown in FIGS. 1 to 3, and its configuration will be explained based on FIG. 1. The illumination device 1 that illuminates the original S includes a straight lamp 2' as a linear light source, and a reflecting mirror shade 3 as a reflecting means for focusing the light from the straight lamp 2 onto the original S. Furthermore, this straight tube lamp 2 includes an elongated glass straight tube 4 as a tubular member, and segments AI, A2, A3, A4, A as light emitting portions a at predetermined intervals within this elongated glass straight tube 4.
It consists of filaments 5 and 5. Here, the reflecting mirror shade 3 is provided approximately parallel to the straight tube lamp 2, and the segments A I, A
2. Convex portions 3a, 3b, 3c, 3d, 3e each having a substantially arcuate cross section are located at positions corresponding to A3, A4, and A5.
are provided for each. Next, an example of the operation of this embodiment will be explained based on Fig. 2. First, in order to light up the lighting device 1, that is, the straight tube lamp 2, when the filament 5 is energized, the segments AI, A2, A3, A4, and A5, which are the plurality of filament winding portions formed in the filament 5, are turned on. Each point emits light due to overheating, and the straight tube lamp 2 as a whole becomes a linear light source. And, as shown in Figure l,
The light intensity distribution of the light irradiated from the straight tube lamp 2 to the irradiated position L-H on the document S surface through the reflecting mirror shade 3 provided almost parallel to the straight tube lamp 2 is as follows. , 3rd
As shown in the figure, each segment AI. A2, A3, A4. A total light amount distribution E is obtained by combining the light amount distributions corresponding to A5.

Here, the reflecting mirror shade 3 is located at the irradiated position L on the surface of the original S.
- In order to suppress the unevenness of the unevenness in the R, protrusions 3a, 3b, 3c, 3d, and 3e are provided at positions corresponding to each of the segments AI, A2, A3, A4, and A5, and
Each of the above segments AI, A2, A3, A4, A
The light from 5 is diffused in the longitudinal direction of the straight tube lamp 2.

Therefore, for example, as shown in FIG.
Then, in the conventional example shown in FIG. 8, the light from l segments is diffusely reflected only up to the range of width X, but in this embodiment, the range of width Y, which is wider than the width X, can be illuminated. Even if the distance D is short, each segment AI,
Irradiated position L- corresponding to A2, A3, A4, A5
position on R and segments A I, A2, A3,
It is possible to reduce ripple unevenness with the position corresponding to A4 and A5. In FIG. 2, only the main parts are extracted and shown schematically in order to make it easier to understand the effect of the reflecting mirror shade 3 on diffusing light.
3b, 3c, 3d, and 3e can actually be implemented by providing them on any or all of the surfaces of the reflective mirror shade 3 shown in FIG. However, it is more effective to install it closer to the reflective surface of the straight tube lamp 2. Next, a second embodiment of the present invention is shown in FIG. 4, and the same parts as in the first embodiment will be described with the same reference numerals. Convex portion 3 provided on the reflecting mirror shade 3 in the above first embodiment
a, 3b, 3c, 3d, and 3e are approximately arcuate in cross section and have curvature, but the convex portions 3a, 3b, 3c, 3d, and 3e of the reflecting mirror shade 3 in this embodiment are as follows.
It is made of two planes shaped like a mountain. Therefore, compared to the first embodiment, the convex portions 3a, 3 have a slightly inferior diffusion efficiency due to the lack of curvature.
b, 3c, 3d, and 3e are easy to form.

The other configurations and operations are the same as those of the first embodiment, so their explanation will be omitted.

Next, a third embodiment of the present invention is shown in FIG. 5, and the same parts as in the first embodiment will be described with the same reference numerals. Convex portions 3a provided on the reflective mirror shade 3 in this embodiment,
3b, 3c, 3d, and 3e are formed by bending and raising the plate piece 3b formed by cutting out the base lO of the main body of the reflecting mirror shade in a U-shape, so that the plate piece l2 has a substantially arc-shaped cross section. Therefore, this embodiment also has the same diffusion effect as the first embodiment, and the through holes 11 formed when the plate piece 12 is bent up enhance the heat dissipation effect of the lighting system.
It is possible to suppress the temperature rise of the lighting device itself. The other configurations and operations are the same as those of the first embodiment, so their explanation will be omitted.

Note that the material of the reflective mirror shade, the number of reflective surfaces, etc. in this embodiment are not particularly limited, and it goes without saying that they can be changed depending on the purpose.

[Effects of the Invention] As explained above, in the present invention, even when the illumination device is brought close to the document surface, there is no risk of ripple unevenness occurring at the irradiated position on the document surface, so that the light from the light source is reduced. can be used effectively.

Furthermore, by shortening the distance between the light source of the illumination device and the document surface, the device can be made more compact.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the overall configuration of a first embodiment of the present invention, FIG. 2 is a schematic sectional view showing the main parts of this embodiment, and FIG.
4 is a schematic cross-sectional view showing a second embodiment of the present invention, FIG. 5 is a schematic cross-sectional view showing a third embodiment of the present invention, and FIG. 6 is a plan view showing a conventional linear light source, FIG. 7 is a schematic sectional view showing the operation of the conventional example, and FIG. 8 is a schematic sectional view showing main parts of the conventional example.
FIG. 9(a) is a diagram showing the light amount distribution of the illumination device in the conventional example, and FIG. 9(b) is a diagram showing the light amount distribution when the light source of the illumination device in the conventional example is brought close to the document surface. Explanation of symbols 1...Lighting device 2...Straight tube lamp (linear light source) 3...Reflector shade (reflection means) 3a, 3b, 3c, 3d, 3e-Convex portion (diffusion means) 4. ...Elongated glass straight tube (tubular member) 5...Filament a...Light emitting part No. 4 Figure 5 Figure S S /

Claims (1)

[Claims] A linear light source in which a plurality of light emitting parts are arranged within a tubular member, and a reflecting means provided substantially parallel to the linear light source and reflecting light from the linear light source. A lighting device characterized in that a diffusion means for diffusing light from the light emitting section in the longitudinal direction of the linear light source is provided at a position on the reflecting means corresponding to the position of the light emitting section. .