JPS587626A - Exposure adjusting method of microfilm copying machine - Google Patents

Abstract

PURPOSE:To execute a suitable exposure adjustment even in case of a remarkable change of density of a film or a copying magnification, by adjusting the exposure to a reference value by means of an automatic exposure adjustment, and subsequently, switching it to a manual exposure adjustment, and finely adjusting the exposure. CONSTITUTION:The quantity of light of a lamp 7 is adjusted by setting a switch 6 to the automatic side, and sending divided voltage of a voltage dividing circuit 5 to a V/I converter 8. On the other hand, a motor controller 11 automatically adjusts a diaphragm 9. As a result, the diaphragm and the quantity of light of the lamp are automatically adjusted so that an output of a photoelectric element 1 becomes a reference value. Subsequently, the quantity of light of the lamp is finely adjusted by setting the switch 6 to the manual side, sending the divided voltage of a voltage dividing circuit 12 to the converting circuit 8, and adjusting a variable resistance Rv. In this way, the exposure adjusted in advance by means of the automatic adjustment is finely adjusted by the manual adjustment, therefore, it is possible to execute a suitable exposure adjustment even in case of a remarkable change of density of a film or a copying magnification.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure amount adjustment method for a microfilm copying machine, which enables appropriate exposure adjustment even when there are large changes in film density or copying magnification.

Microfilm copying machines are known that have automatic exposure adjustment and manual exposure adjustment as independent functions. In such a device, in the case of automatic exposure adjustment, the KN adjustment is performed so that the exposure amount becomes a constant value based on the background density or average immersion of the film, regardless of the film sit, contrast, or type of image. It is done. And the film I
A manual adjustment function was used to adjust exposure appropriately depending on IItL, contrast, type of iiigI, etc. The manual exposure adjustment can be done either by keeping the light intensity of the exposure rung constant and manually changing the lens aperture, or conversely by keeping the lens aperture constant and manually changing the light intensity of the rung. Nine. However, with this type of manual exposure adjustment method, when manually adjusting to increase magnification or film density, a large adjustment range is required, making it difficult to make minute adjustments or There are drawbacks such as the need to increase the width of the knob.

That is, in a conventional microfilm copying machine that has automatic exposure adjustment and manual exposure adjustment as nine independent functions, the film 6 medium density contrast, IIR * type,
Appropriate KIi exposure amount in response to large changes in copy magnification, etc.
It was very difficult to get things right.

Therefore, it is an object of the present invention to provide an exposure amount adjustment method that can provide an appropriate exposure of 11111 gM even when there are large changes in fill density and copying magnification.

That is, in the present invention, approximately the appropriate exposure amount K is determined by automatic exposure adjustment.
By combining automatic exposure adjustment and manual exposure adjustment, we first set the exposure amount to the standard value using automatic exposure adjustment, and then switched to manual exposure adjustment to fine-tune the exposure amount. It is characterized by the fact that

According to this method, since the automatic exposure adjustment is roughly adjusted to an appropriate exposure amount, the amount of manual adjustment for changes in film angle or magnification is small, and the exposure amount can be finely adjusted to an appropriate amount. It becomes possible to do so.

Hereinafter, the method of the present invention will be described with reference to the accompanying drawings.
4.

The accompanying drawings are circuit diagrams of automatic and manual exposure circuits for carrying out the method of the invention.

An electrical signal indicating the amount of light in the vicinity of the photosensitive surface, which is detected by the electronic element 1 placed at a known position, is amplified by the amplifier 2 and sent through the switch 3 to the sample halt circuit 4.
, a resistor R, a voltage dividing circuit 5 consisting of R1, and an automatic/manual changeover switch 6 to control the current applied to the balance f7.
/I conversion circuit 8 and further output to a door control circuit 11 that drives a motor 10 that adjusts the aperture 9. During automatic adjustment, the switch 3 is closed, the switch 6 is switched to the automatic side, and the sample hold circuit 4 is set to Templing mode PK. The output voltage of the T/Gluhole circuit 4 is divided by resistors R and R8 and input to the V/I converter circuit 8 via a switch. The V/I conversion circuit 8 operates to lower the output current when the input voltage is high, and to increase the output current when the input voltage is low. Adjust the light intensity. On the other hand, the motor control circuit 11 automatically adjusts the aperture.

As a result, the ah and light amounts are automatically adjusted so that the output value of the photoelectric element 1 becomes the reference value. After automatic adjustment is complete,
The switch 3 is opened, the sample hold 4 enters the hold mode and holds the output voltage at that time, and the motor control circuit 11 stops the motor 10 to keep the exposure amount constant.

When performing manual I#u, set the switch 6 to manual and send the output voltage divided by the voltage divider circuit 12 made up of resistors R3 and R4 and variable resistor Rv to the V/1 transfer circuit II8. do. By manually adjusting the variable resistor Rv, the input voltage to the V/I conversion circuit 8 can be changed, and the light intensity of 27 zo can be finely adjusted to a more appropriate value according to the film II and magnification. .

As described above, according to the present invention, since the exposure amount that has been adjusted in advance by automatic adjustment is finely adjusted by manual adjustment, the adjustment range of manual adjustment is reduced, and fine adjustment is fully possible. .

In the above-described embodiment, the aperture was held constant and the lamp light intensity was manually adjusted, but the same effect can be obtained by keeping the lamp light intensity constant after automatic adjustment and adjusting the aperture manually. It would be obvious to the Ministry of Industry.

[Brief explanation of the drawing]

The accompanying drawings are circuit diagrams of automatic and manual exposure adjustment circuits for implementing the method according to the invention. 1### Generator element, 2man increaser 4I device, 3... Selector switch 511@・Sangle halt circuit, 5.12・
・Voltage dividing circuit,

Claims (1)

[Claims] K111 to adjust the exposure amount to the standard value by automatic exposure adjustment
A method for adjusting the exposure amount of a microcopying machine, characterized in that the exposure amount is finely adjusted by adjusting the exposure amount and then switching to manual exposure adjustment.