JPH0540513Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an exposure adjustment device for a copying machine.

BACKGROUND OF THE INVENTION In general, the optical system of a copying machine is usually provided with a plurality of exposure adjusting plates in the emitted light area of the exposure light source or in the reflected light area from the original to prevent uneven printing such as uneven printing. be. For example, Japanese Utility Model Application No. 56-75755 and Japanese Utility Model Application Publication No. 62-13074 disclose techniques regarding such exposure adjustment plates.

Problems that the invention aims to solve However, since all conventional exposure adjustment plates are designed based on the idea that adjustments are made during manufacturing, the contact glass or top cover must be removed to make adjustments during use. It's becoming more and more difficult to do so. Therefore, adjustment on the user side is virtually impossible. On the other hand, user maintenance has become important in recent low-cost copying machines.

Therefore, it is an object of the present invention to make it possible to easily adjust the uneven baking that occurs frequently.

Means for Solving the Problems In this invention, in a copying machine with a movable document table,
The operating knob of the exposure adjustment plate is normally covered by the document table, but is configured to be exposed for operation when the document table is moved.

Effect The control knob is exposed when the document table is moved in one direction. When the operating knob is operated in the exposed state, the exposure adjustment plate corresponding to the operating knob is displaced to change the range of light blocking.

Embodiment FIG. 1 shows a copying machine with a movable document table in which the present invention is implemented, in which an operating knob 4 for adjusting exposure is visible below the document table 2 through a contact glass 3 in the upper part of the main body 1. There are several. This operating knob 4 is movable within each regulation hole 5. In addition, 6 is a lens array,
7 is a paper feed cassette, and 15 is a paper discharge tray. The document table 2 has the contact glass 3 and a document holder 8, and the entire document table 2 can be moved back and forth in the direction of arrow A. The document holder 8 is provided with a mat 9 on its inner surface.

The cross-sectional view in FIG. 2 clearly shows the structure of the exposure adjustment device including the operating knob 4, and shows the vicinity of the exit of the light emitted from the light source 10 consisting of a halogen lamp and directed by the reflecting member 11. An exposure adjustment plate 12 is arranged to block the exposure. One end of the adjustment plate is connected to the operating knob 4 via a lever 13.

FIG. 3 shows the device in a plan view, and in this embodiment, there are six adjustment plates 12 and six operation knobs 4 each. In FIG. 2, 14 is a photosensitive drum, which rotates in the direction of arrow B. 1
6 is a filter glass arranged at one end of the lens array 6. A relatively large opening 18 is provided in the frame 17 of the main body 1, and light from the light source 10 travels toward the document table 2 through this opening 18. The light reflected by the document on the document table enters the main body through the opening, is focused by the lens array 6, and is guided to the photosensitive drum 14.

Incidentally, the adjustment is performed with the document table 2 moved from the state shown in FIG. 5a to the state shown in FIG. 5b. At this time, the frame 17 exposed from the document table 2 has a recess 19, and the operating knob 4 is disposed within this recess. As shown in FIG. 4, a plate spring 20 is attached to the lower part of the flange 4a of the operation knob 4, and the flange 4a is moved into the recess 1 by the elastic force of the plate spring 20.
It is elastically in contact with the upper wall 21 of 9. As a result, the operation knob 4 is given a moving load, and its position (and therefore the position of the adjustment plate) is kept stable.
Now, when the operating knob 4 is moved in the direction of arrow C shown in FIG. 3, the adjustment plate 12 is also moved in the direction of arrow C accordingly. Each adjustment plate 12 can be moved independently of each other, thereby allowing fine adjustment of exposure.

Next, FIG. 6 shows only the adjusting plate, operating knob, and lever of another embodiment. Here, the adjustment plates 12a, 12b, and 12c are connected, and the adjustment plates are provided with a round hole 22 on one side and an elongated hole 23 in the longitudinal direction of the adjustment plates as holes for connection. Lever 1 in these holes
For example, when the operating knob 4b is driven, both adjustment plates 12a and 12b move, so that the two adjustment plates move at the same time at the joint. The other ends of the adjusting plates 12a and 12c, which do not have a connecting portion, are driven by operating knobs 4a and 4d.
In the embodiments shown in FIGS. 1 to 5 described above, the movement of the adjustment plates is independent of each other in stepwise adjustment, whereas in the embodiment shown in FIG. 6, adjacent parts are adjusted continuously.

Effects of the invention According to the invention, when the document table is moved in one direction, the operation knob is exposed, so the user can easily adjust the position of the exposure adjustment plate and take temporary measures when uneven printing occurs. You can take it. Further, even if the original is partially burnt, it is possible to obtain a copy without uneven burning.

[Brief explanation of the drawing]

Fig. 1 is an external perspective view of an exposure adjustment device according to an embodiment of the present invention, Fig. 2 is a sectional view showing the main parts thereof, Fig. 3 is a plan view thereof, and Fig. 4 is a partial structure. and FIG. 5 are diagrams showing the case where the document table is in a predetermined position and the case where it is in a moved position. FIG. 6 is a schematic diagram showing a part of another embodiment of the present invention. 2...Original table, 3...Contact glass, 4,
4a-4d...Operation knob, 10...Light source, 1
2, 12a to 12c... Exposure adjustment plate, 13... Lever, 20... Leaf spring, 22, 23... Long hole, 2
4...Tip pin.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a copying machine with a movable document table, the operating knob of the exposure adjustment plate is normally covered by the document table, but is exposed for operation when the document table is moved. An exposure adjustment device for a copying machine, characterized in that: (2) The exposure adjustment device according to claim 1, wherein the operating knob is given an elastic movement load by an elastic means. (3) The exposure adjustment device according to claim 1, wherein there are a plurality of adjustment plates and a plurality of operation knobs. (4) The exposure adjustment device according to claim 3, wherein the adjustment plate and the operation knob are connected by a lever. (5) Adjacent adjusting plates are connected to each other, and the two adjusting plates are simultaneously driven by the lever acting on the connected portion, as set forth in claim 4 of the utility model registration claim. Exposure adjustment device.