JPS5886573A - Exposure adjusting device of copying machine - Google Patents

Abstract

PURPOSE:To obtain the best exposure easily by arranging two identical slit rolls oppositely at a left and a right symmetrical position on the optical axis of a photosensitive drum. CONSTITUTION:At a left and a right symmetrical position on the optical axis 1A of a photosensitive drum 1, two identical slit rolls 2 and 3 are arranged oppositely, a rotation driving mechanism for said slit rolls 2 and 3 is provided to make an adjustment to exposure for the best copying, and a step motor 6 drives the rolls through a gear 4. Those slit rolls are step cams each having an (n)-step peripheral contours PCs with radii a1, a2-an from the center C of rotation, and the rolls 2 and 3 are rotated in the opposite direction to adjust the exposure.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure w4 adjustment device for a copying machine.

In the exposure equipment of conventional copying machines, there are generally two methods: one is to fix the slit and only control the lamp voltage to obtain the optimum exposure, and the other is to manually replace the slit and control the lamp voltage to obtain the optimum exposure. He had been hired.

However, with these conventional methods, as the types of paper and paper become more diverse and the copy magnification range expands, the lamp voltage control range becomes dramatically wider, and as a result, the control system becomes unstable9. It took a long time to stabilize, and as a result, the amount of noise per unit time decreased. 9. The control system became more complicated and the cost increased, and the reliability also decreased accordingly. There was a problem with this.

The purpose of the present invention is to solve the limitations of the prior art, and to create an optimal
The present invention provides an exposure adjustment device for a copying machine that can control light very easily and quickly.

According to the present invention, such an object is to arrange the same slit rolls facing each other at symmetrical positions on the optical axis of the photosensitive drum in an exposure device of a copying machine, in order to obtain optimal copies. The peripheral contour of the slit roll is rotated once by the desired amount from the slit bag to the slit roll. When the exposure is performed, the optimum slit width is calculated based on all relevant factors to obtain the optimum combination of the type of original, percentage of magnification, and voltage of the original at that time. % to 1
This is achieved by K.

Next, the present invention will be described in more detail with reference to embodiments of the present invention based on 1 Attachment 5uiy.

Figure 1 shows exposure adjustment of a copying machine as an embodiment of the present invention*
FIG. 2 is a plan view schematically showing the device. Exposure of this fruit m tsuba 1
In the I511 device, one identical slit #2 and #3 are placed facing each other at symmetrical positions on the optical axis L^ of the photoreceptor drum L, and these slit rolls 2 and 3 are optimally copied. For exposure 111111 to obtain 111111, a rotational drive mechanism is provided to rotate by a desired amount as necessary. This rotary drive machine III# rotates a gear 4 attached to the rotating shaft of the slit roll 2, a gear 5 that meshes with this gear 4 and is attached to the rotating shaft of the slit roll 3, and a gear 5 that is attached to the rotating shaft of the slit roll 3. It is equipped with a stem motor 6 for causing the movement.

The slit rolls 2 and 3 each have a radius a1 from their rotation center C, as shown in an enlarged cross section in FIG.
, a2, a3...an-1,, a, n
This is a step cam with a peripheral PC consisting of several steps. These slit rolls 2 and 3 have the same perimeter.

In this embodiment, since they are rotated in opposite directions, the photoreceptor drum 10 is placed at a symmetrical position on the optical axis IA, with the center C
At the same time, their peripheral PC% and optical axis l
It is always arranged symmetrically with respect to ^.

In Fig. 3, the distance between the centers C of slit reels #2 and 3 is ^, and the slit reel is formed between the slit reels 2 and 3 centering on the optical axis 1^ with the steps of the radius facing each other. Let y be the slit width.

y-＾-λ town ・・・・・・・・・・・・・・・(1
) holds true.

Then, type of original to be exposed J-copy magnification,
Considering all related factors such as voltage to obtain the optimum copy, calculate the slit width y necessary for obtaining the optimum exposure to obtain the optimum copy in each case by various calculations, and use the above formula (1). The slit rolls 2 and 3 may be designed to have a peripheral contour consisting of each step having the calculated radius by calculating the medium diameter radius of each step corresponding to the calculated radius.

Since it has a configuration like that, the step mall 6tM
By rotating Jc liters 2 and 3 by a desired step, it is possible to obtain the optimum exposure and slit width according to the type of document to be exposed at that time, the copy magnification, and the voltage level. can.

In the above-mentioned embodiment, the slit width was changed stepwise in order to adjust the exposure amount, so that the slit width could be changed digitally. It is also possible to have a configuration in which it can be changed in a so-called analog manner.

For example, Surin)a-Rule 2 and 3 in the above embodiments
Instead of making the peripheral contour PC into a two-step shape, the rotation angle and eccentricity (cam lift amount) of the slit reel are made to be a straight line as shown in the curve ^ in Fig. A continuously variable slit width y can be provided.

y w Q. +λaOf (1') -a6mmmm
m@...(2) ζ-, C0 = minimum slin FI between slit reels - rotation angle of slit reel, so that the relationship between eccentricity and rotation angle is a linear relationship as shown in the slit reel diagram. It is relatively difficult and expensive to process a slit roll, so if workability and cost are considered, a rail with a circular cross section with its center of rotation centered may be used as the slit rail.

In this case, the relationship between the amount of eccentricity (cam lift amount) and the rotation angle is as shown in the diagram JIB shown in FIG. Therefore, when rotating slit rolls facing each other,
It is possible to provide a continuously variable slit width y as expressed by the following equation.

'V' C6+ 2 boSln 10
(3) When the width of these slits is made to be continuously variable.

Of course, it can be used as a rotational drive mechanism for the slit roll.

There is a need to use a peak f4 that can continuously change the rotation angle instead of a f4-y.

As mentioned above, according to the exposure adjustment device for a copying machine according to the present invention, it is possible to automatically provide the slit width for optimal exposure simply by rotating two opposing slits in a stepwise manner or continuously. Exposure adjustment can be carried out very simply and easily with a small voltage, and the control range of the 2-f voltage can be kept within an extremely small range, and the dead time for stabilization is 1cII! Therefore, it is possible to copy many types of originals at high speed and always with optimum exposure.

[Brief explanation of drawings]

FIG. 1 of the accompanying drawings shows the exposure N! of a copying machine as one embodiment of the present invention. A plan view schematically showing the I device, Figure J [/
An enlarged view showing in detail the periphery of the slit roll used in &J's device, and FIG. 3 is an enlarged partial view showing in detail the positional relationship between the photosensitive drum and the slit roll in the device of FIG. , Fig. 5 are diagrams showing the relationship between the eccentricity of the slit roll used in another embodiment of the present invention and (2) the rolling angle. 1--Photosensitive drum, IA...e optical axis, 2.3...
・Slit roll, PC--peripheral contour, 4.5...-
Gear, 6...Step motor, yl/slit width Fig. 1 Fig. 3 Fig. 4 Fig. 5

Claims (1)

[Claims] Two identical slit rolls are placed facing each other at symmetrical positions on the optical axis of the photosensitive drum, and the slit rolls are rotated by a desired amount as necessary to adjust the exposure to obtain the optimum copy. When the slit roll is rotated by the desired amount, the slit roll is rotated by the desired amount to obtain the optimum magnification, lamp voltage, etc. An exposure adjustment device for a copying machine, characterized in that the exposure adjustment device for a copying machine has a peripheral contour that provides an optimal switching width calculated according to all related factors for