DE1081161B - Device for protecting the photoelectric layers in image converter devices - Google Patents

Description

Photoelectric layers, for example the layers of cesium oxide photocathodes of electron-optical ones Image intensifiers are very sensitive to overload caused by excessive radiation intensities. Since the Bildwandlerr, ears are also very expensive, facilities must be provided that are suitable, the photoelectric layer both during operation and in the idle state before destruction to protect.

The protection of the photoelectric layer in image converter tubes is achieved according to the invention by a closure through which the radiation access to these shifts is blocked during the shutdown and in the operating state as soon as the incident occurs Radiation assumes a value that endangers the layer, is throttled or blocked, and the im optical beam path is arranged so that the relative brightness distribution due to its adjustment the photocathode is not changed. The device can be closures known per se act that are biased at rest, for example, and the radiation entry, if necessary also close the beam exit openings. The device according to the invention ensures im The rest of a protection in two respects, besides the protection of the photocathode from too intense Radiation, a protection of the optics against mechanical damage, especially during transport.

The arrangement according to the invention can be used both for image converter devices for hand observation as well for stationary or mobile use where the devices are built into a vehicle Find.

In the first case it is provided that a movable handle is arranged in the handle so that when Grasp the handle, the handle is pressed in and this movement is mechanically set to a state of rest closed shutter is transmitted.

In the second case, there are two ways of actuation in a corresponding embodiment of the invention of the shutter. On the one hand it is possible that the closure is effected by mechanical transmission members is controlled by the process of inserting or removing the device into or from the holder. This arrangement is useful because the devices are temporarily removed from their brackets, to be replaced either by day vision devices or to provide a direct view for the operator to release.

On the other hand, it is possible according to the invention to use an electrically operated lock. It is provided that the shutter is closed in the de-energized state, but that its opening is closed via the Protection facility

of the photoelectric layers

in image converting devices

Applicant; -

LICENTIA patent administration? - G. mb H. _r Frankfurt / M., Theodor-Stern-Kai 1

Hellmut Schulz, new. Iseiiburg ,, ·
and Waldemar Herrström, Frankfurt / M.,
have been named as inventors

Supply voltage is controlled. The further development of this arrangement makes it possible to have a Auxiliary receiver the size of the opening of the locking

device to regulate depending on the radiation intensity impinging on the image converter. This latter device not only provides automatic overload protection for the photocathode of the image converter tube, but at the same time causes an improvement in the contrast on the Fluorescent screen in that the control circuit is set so that even in the brightest parts of the Image is not yet saturated.

In a further, preferred embodiment of the invention, when the image converter is arranged with variable visual axis is equipped, the visual axis of the auxiliary receiver changed at the same time as that of the image converter. The shutter of the imager is locked as long as the auxiliary receiver is not in operation.

In the figures are two devices in which the device according to the invention is installed, shown ..

Fig. 1 shows a handheld monocular observation imager;

Fig. 2 shows a possible Ausfüh ^ ungsart of a device for installation.

1 with the handle of the image converter is referred to, 2 represents its lens with the shutter 3. The Shutter 3 is opened or closed via the hand switch 5 by means of the connecting member 6. That Eyepiece 4 enables the sighted object to be observed on the screen. Also the eyepiece can be provided with a lock.

"-" -'- '-' ■ "■ ■ '■ 009 508/345

In Fig. 2, 13 represents the lens housing with the lens openings 8. On the diaphragm 9 is a Nose 12 attached so that when the device is inserted into the device slot 10, this nose on a paragraph remains hanging in the housing wall 11 and thereby pulls the diaphragm 9 away from the lens openings. in the In the not extended state, the diaphragm 9 is held in front of the openings 8 by a spring (not shown) held.

Claims (8)

Patent claims: 1. A device for the protection of overload sensitive photoelectric layers in picture ¹ S converter devices, characterized by a shutter (3) through which the radiation access to these layers during the operation of rest is locked and in the operating state as soon as the incident radiation a layer hazardous value assumes, is throttled or blocked and which is arranged in the optical beam path so that the relative brightness distribution on the photocathode is not changed by its adjustment. 2. Device for image converter devices for hand use according to claim 1, characterized in that that in the handle (1) a movable hand switch (5) is arranged so that when grasping of the handle (1) the hand switch (5) and this movement mechanically a shutter (3) which is closed in the idle state, for example in the manner of an iris diaphragm will. 3. Device on image converter devices for installation according to claim 1, characterized in that a screen (9) by mechanical transmission members from the process of insertion or removal of the device into or out of the holder (12). 4. Device on image converter devices for installation according to claim 1, characterized in that the shutter is operated electrically, is excited by the supply voltage and in the de-energized state State is closed. 5. Device according to claim 4, characterized in that the electrically operated shutter is operated at the same time as the supply voltage for the image converter is switched on. 6. Device according to claim 1, 4 or 5, characterized in that the closure at the same time is designed as an electrically controlled aperture, the aperture value of an auxiliary receiver is regulated as a function of the radiation intensity impinging on it. 7. Device according to claim 1, 4, 5 or 6, characterized in that at Bildwandleranofdnung with a variable visual axis, the visual axis of the auxiliary receiver runs concurrently with that of the imager is changed. 8. Device according to claim 1, 4, 5, 6 or 7, characterized in that the closure locks is as long as the auxiliary receiver is not in operation. 1 sheet of drawings © 009 50 & 345 *.