JPH0576623B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a slit exposure illumination device for illuminating the surface of a document in a projection printing apparatus or the like.

Conventional structure and its problems Conventionally, this type of slit exposure illumination device has been equipped with a light distribution adjustment mechanism for adjusting the illuminance distribution, and there are two types as shown in Fig. 10A and B. things are known. The basic structure of these is to provide a light shielding plate 3 between a linear tube 2 provided along the main reflector 1 and the original 6, and the one in FIG. The rotation angle of the light shielding plate 3 is changed on the front side of the tube, and the 10th
In the case of FIG. B, the amount of protrusion of the light shielding plate 3 is also changed. In FIGS. 10A and 10B, 4 indicates a sub-reflector and 5 indicates a stage glass.

However, in all of these methods, the stage glass 5 must be removed once to adjust the illuminance distribution, and it is not possible to adjust the illuminance distribution while monitoring it. In addition, in these cases, the light shielding plate 3 is located relatively far from the tube 2, so the illuminance distribution is affected by the light from the entire plurality of light emitting segments, so the light shielding plate 3 is divided into several parts. Due to this structure, even if a portion of the light shielding plate 3 is adjusted, the illuminance distribution cannot be finely adjusted, and therefore it is difficult to obtain a predetermined illuminance distribution.

OBJECTS OF THE INVENTION The present invention provides a slit exposure illumination device that can monitor and adjust the illuminance distribution while maintaining the positional relationship with the irradiated surface in the actual state of use.

Structure of the Invention The slit exposure illumination device of the present invention includes a main reflector and a linear tube provided along the main reflector and provided with a filament having a plurality of light emitting segments inside. A slit exposure illumination device for document illumination arranged so as to provide a predetermined distribution of illuminance, wherein a plurality of notches are provided in a rear portion of the tube close to the tube of the main reflector. A tongue piece is formed at the rear of the bulb and corresponds to each light emitting segment, and the tongue pieces are deformable independently from each other due to the notch.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view of a slit exposure illumination device which is an embodiment of the present invention, and FIG. 2 is a perspective view of the same essential parts.

As shown in FIG. 1, a linear tube 2 is provided along a main reflector 7 having an elliptical or parabolic surface. A stage glass 5 is provided on the front side of the main reflector 7. In the figure, 4 is a sub-reflector;
6 indicates a manuscript.

As shown in FIG. 2, the main reflector 7 has a plurality of notches 8 in the rear part of the tube close to the tube 2 in a direction perpendicular to its length, and a plurality of notches 8 in the length direction. 9 are provided, and a plurality of tongue pieces 7a, 7b, 7c, 7d, and 7e are formed by these. These tongue pieces 7a to 7e can be freely deformed independently of each other in any direction by cuts 8 and 9. The tube 2 includes a plurality of light emitting segments 11 in the glass tube 10 along the tube axis direction.
A filament 11 is provided having a, 11b, 11c, 11d, 11e. The tongues 7a, 7b, 7c, 7d, and 7e are provided behind the light emitting segments 11a, 11b, 11c, 11d, and 11e in correspondence with the respective light emitting segments.

Since it is configured as described above, the tongue pieces 7a~
By adjusting the angle of one or more of the light emitting segments 11a to 11e of the tube 2, for example, by adjusting the angle of one or more of the light emitting segments 11a to 11e of the tube 2, the direction of reflection of the light emitted backward from the light emitting segments 11a to 11e of the tube 2 can be changed. The illumination intensity can be set to a predetermined distribution. Moreover, in this device, the illuminance distribution adjustment point is closer to the tube 2 than in conventional devices, so the illuminance distribution corresponding to each light emitting segment 11a to 11e can be finely and easily adjusted, and the document Since the tongue pieces 7a to 7e are adjusted at the position opposite to the stage glass 5, the illuminance distribution can be adjusted while the stage glass 5 is kept in the actual state of use.

Next, a specific example of the present invention will be described.

In the structure shown in FIGS. 1 and 2, a JK75V150W halogen light bulb was used as the bulb 2.
This halogen bulb has a glass tube 10 with an outer diameter of 6 mm.
The total length of the lamp is 258 mm, and the number of light emitting segments of filament 11 is 5. Such a tube 2 is installed along the main reflector 7, and while the stage glass 5 is kept in the actual state of use, the tongue piece 7a is 1.8 mm, the tongue piece 7b is 0.5 mm, and the tongue piece 7c is 0 mm (without deformation). ) Adjustments were made by deforming the tongue 7d by -1.0 mm and the tongue 7e by 1.5 mm. Before the adjustment, the document surface illuminance was as shown in the curve in Figure 3, but after the adjustment, it changed to the curve in the same figure. The illuminance on the document surface was as shown, and the illuminance distribution was uniform. Here, the tongue pieces 7a to 7e are all in the position shown by the solid line in FIG. 4 before adjustment,
After the adjustment, for example, it is deformed by a distance l to the position shown by the two-dot chain line in the figure. In the above, the distances with a negative sign in front of them are the cases when the distance is deformed in the direction of the arrow I, and the distances without a negative sign are the cases when the distance is deformed in the direction of the arrow O.

FIGS. 5 to 9 show how the document surface illuminance changes when each tongue piece is deformed individually. That is, FIG. 5 shows only the tongue piece 7a,
FIG. 6 shows only the tongue piece 7b, FIG. 7 shows only the tongue piece 7c, FIG. 8 shows only the tongue piece 7d, and FIG. 9 shows the tongue piece 7e.
When changing only the document surface illumination,
The solid lines before the adjustment change to the broken lines and the dashed-dotted lines after the adjustment, respectively.

In addition, when experiments were conducted using filaments in which the number of light-emitting segments was changed, results similar to those described above were obtained.

Further, although the above description is for the case where the illuminance distribution is made uniform, the present invention can be implemented in the same way when obtaining the illuminance distribution where both ends are raised from the center.

Effects of the Invention As explained above, according to the device of the present invention,
Changing the direction of reflection of light emitted rearward from each light-emitting segment of the tube by adjusting the angle in the front-back direction of the tongue piece formed on the rear side of the tube close to the tube of the main reflector. Therefore, even if there are variations in the illuminance distribution, the illuminance on the exposure surface can be easily made to have a predetermined distribution. Furthermore, since the tongue is close to the tube, it is possible to finely and easily adjust the illuminance distribution corresponding to each light emitting segment of the tube. Therefore, it is possible to adjust the illuminance distribution while keeping the stage glass in the actual state of use.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a slit exposure illumination device that is an embodiment of the present invention, FIG. 2 is a perspective view of the same main part, and FIG. 3 is a diagram showing an example of adjusting the illuminance distribution using the same device. FIG. 4 is a cross-sectional view showing a modified example of the tongue piece in the same device, FIGS. FIG. 3 is a side sectional view showing a conventional slit exposure illumination device. 2...Tube, 7...Main reflector, 7a, 7b, 7
c, 7d, 7e... tongue piece, 8, 9... notch,
10...Glass tube, 11...Filament, 11
a, 11b, 11c, 11d, 11e... Light emitting segments.

Claims (1)

[Claims] 1 A main reflector and a linear tube provided along the main reflector and provided with a filament having a plurality of light emitting segments inside are arranged so as to distribute the illuminance on the exposure surface in a predetermined manner. A slit exposure illumination device for illuminating a document, wherein a plurality of notches are provided in a rear side portion of the tube close to the tube of the main reflector so that the notches are located behind the tube and each A slit exposure illumination device characterized in that tongue pieces are formed corresponding to the light emitting segments, and the tongue pieces can be deformed independently of each other by the cut.