JPS598945B2 - electron beam shatter tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam shutter tube using a novel electron beam shutter device.

In order to image a subject that changes or vibrates at high speed, an extremely short exposure time is required.

In photography, exposure is performed by mechanical means, but in image tubes that convert optical images using the photoelectron emission effect, a net-like electrode is provided close to and parallel to the photocathode, and is usually located at a distance from the photocathode. Electrons corresponding to the optical image projected onto the photocathode at the desired time are set at a high potential to prevent the electron beam image from passing through, and a potential higher than the photocathode is applied for a desired time width at a desired exposure time. The beam is incident on the fluorescent surface of the image tube to form the above-mentioned optical image, which is then recorded by exposure to photographic film or by other television imaging.

In addition, a deflection electrode consisting of two deflection plates parallel to and sandwiching the passage is provided at an appropriate position for the path of the electron beam image between the photoelectric layer and the fluorescent surface. A voltage is applied between the plates to deflect the electron beam image so that it does not enter the fluorescent surface, and at a desired exposure time, the voltage between the two deflection plates is changed, and in the process of changing the voltage, the two plates are When the voltage on the deflection plate becomes small, an electron beam image corresponding to the optical image projected onto the optical surface is incident on the fluorescent surface of the image tube to form an image of the optical image.

An image tube having the above-mentioned functions is called a Shasta tube, and is capable of observing high-speed development.

The above-mentioned functions can also be performed in a television imaging device L having an image section, such as an image orthicon, by placing a mesh electrode or a deflection electrode on the image section.

The structure and operation of a conventional Shatta tube, as well as its drawbacks, will be explained below using an image tube type Shatta tube as an example.

The structure and operation of the part that functions as a Shasta tube in the image orthicon tube type Shasta tube is exactly the same, and the image orthicon tube type Shasta tube has the fluorescent surface of the image tube type Nyatsuta tube described below. A storage tube target is provided in place of the image orthicon tube, and a portion of the image orthicon tube having a readout function based on electron beam operation is connected thereto.

FIG. 1 is a diagram showing the cross-sectional structure and power supply connection of an example of a conventional image tube-type shutter tube.

In FIG. 1, 1 is a Shatta tube, 11 is a bottomed cylindrical vacuum vessel of the Shasta tube 1, and 12 is a first vacuum-tight vessel of the vacuum-tight vessel 11.
13 is a photocathode formed on the inner wall of the light incidence window 12; 14 is a mesh electrode provided in parallel to the photocathode 13; 15 is a vacuum-tight container 11; A coaxial and rotationally symmetrical focusing electrode 16 with a fluorescent surface is formed on the inner wall of the light exit window IT provided on the second bottom surface of the vacuum-tight container 11.

The fluorescent surface 16 is connected to the positive electrode of the DC power source 18, the photocathode 13 is connected to the connection point between the negative electrode of the DC power source 19 and the positive electrode of the DC power source 19, and the mesh electrode 14 is connected to the positive electrode of the DC power source 18 through the resistor 20. It is connected to the negative electrode of the DC power supply 19.

Further, the mesh electrode 14 is connected to a rectangular wave pulse power source 22 via a capacitor 21.

The output voltage of the power source 18 needs to be several kilovolts between the photocathode 13 and the focusing electrode 150 to obtain a sufficient focusing effect, and the potential of the fluorescent surface must be several kilovolts higher than the focusing electrode, and the electron Fluorescent surface 16 due to initial velocity dispersion and limitation of photoelectron flow due to space charge.
Several kilovolts to more than ten kilovolts are necessary to reduce blurring of the image caused by the arrival time and lateral spread.

The output voltage of power supply 19 is required to be approximately 30 volts in order to be able to prevent the passage of photoelectrons emitted from photocathode 13 despite the voltage between photocathode 13 and phosphor surface 16 .

Therefore, normally, the electron beam emitted from the photocathode 13 is blocked by the net-like electrode 14 and does not reach the fluorescent surface 16, so that no image is generated.

In such a state, if a positive square wave pulse is input from the square wave pulse power source 22, the net-like negative electrode 14 becomes at a positive potential only during the period of the square wave pulse, and the electron beam image becomes the same as that of the square wave pulse. During the period, the fluorescent light passes through the mesh electrode.
The image is captured in 6.

This rectangular wave pulse is applied to the output voltage of the power source 19 in order to satisfy the focusing conditions of the electron beam image. The voltage must be significantly greater than the voltage, approximately '300 to 2000 volts.

By the way, when imaging a subject that changes at an extremely high speed, the width of the above-mentioned square wave pulse must be narrowed accordingly, but it is not possible to generate a square wave pulse shorter than about 5 nanoseconds and apply 14K to the mesh electrode. This is extremely difficult due to problems with the generation technology, the capacitance of the mesh electrode, and the impedance matching between the mesh electrode and the transmission cable.

FIG. 2 is a diagram showing the cross-sectional structure and power supply connection of another example of a conventional image tube type shutter tube.

In FIG. 2, 3 is a shutter tube, 31 is a bottomed cylindrical vacuum-tight container of the shutter tube 3, 32 is a light entrance window provided on the first bottom surface of the vacuum-tight container 31, and 33 is a light entrance window 32.
34 is a net-like electrode provided close to and parallel to the photocathode 33; 35 is a vacuum-tight container 31;
A focusing electrode 36, which is coaxial and rotationally symmetrical, is a fluorescent surface and is formed on the inner wall of the light exit window 3T provided on the second bottom surface of the vacuum-tight container 31.

38 is an anode plate with an aperture provided in the center.

Reference numerals 39 and 40 denote two deflection plates parallel to and sandwiching the path of the electron beam image, and the two plates are combined to form a first deflection electrode.

41 and 42 are also two deflection plates parallel to the path of the electron beam image and sandwiching the path of the electron beam image.
The second deflection electrode is configured by combining the sheets.

43 is an aperture plate provided between the first deflection electrode and the second deflection electrode.

Approximately 16 kilovolts are applied between the photocathode 33 and the anode plate 38 by the power supplies 45 and 46K, O to 1 kilovolt is applied between the anode plate 38 and the fluorescent surface 36 by the power supply 44, and the power supply 46 Accordingly, 1 to 2 kilovolts is applied between the photocathode 33 and the mesh electrode 34.

Further, the aperture plate 43 is given the same potential as the anode plate 38, and the deflection plate 40 is connected to the deflection plate 40 via a resistor 47.
1 is connected to the positive electrode of a power source 49 via a resistor 48.

Electrode 49 supplies a voltage of approximately 2KV. Furthermore, the deflection plate 4
0 is connected to the output terminal of a high-speed ramp voltage generator 50 via a capacitor 51, and the deflection plate 41 is connected via a capacitor 52.

Note that the anode plate 38, the deflection plate 39, the deflection plate 42, the aperture plate 43, and the negative electrode of the power source 49 are grounded.

Therefore, before the high-speed ramp voltage generator 50 starts changing the voltage, the electron beam image is pulled toward the deflection plate 40 and collides with the aperture plate 43K, so that no image is generated on the fluorescent surface 36.

In this state, when the lamp voltage generator 50 starts changing the lamp voltage in the negative direction, the electron beam is swept, and the deflection plates 39 and 40 and the deflection plates 41 and 42 are at almost the same potential. When this happens, an image appears on the fluorescent surface.

Note that when the sweep speed is extremely high and the electron beam image that has passed through the first deflection electrode reaches the second deflection electrode, the deflection plate 4 is already
In the case where the voltage between the deflection plate 41 and the deflection plate 42 is reversed after passing through the O state, the lamp voltage applied to the deflection plate 41 needs to be delayed by an appropriate amount of time compared to the lamp voltage applied to the deflection plate 40.

Since such a lamp voltage can be realized by short-circuiting a capacitor that has been charged with a high voltage in advance, an extremely rapid change in voltage can be easily obtained.

However, as mentioned above, since the electron beam is accelerated to more than ten kilovolts, a large deflection voltage of several kilovolts is required to obtain a sufficient deflection angle.

Switching circuits for this purpose must use several transistors connected in series because the withstand voltage of the transistor is low, and it is difficult to increase the speed of voltage change in such a circuit, and Since the response time from the input of the trigger signal to the completion of the short-circuiting operation of the transistor is unstable, it is difficult to drive the transistor at a desired timing.

Furthermore, since the speed of voltage change obtained by such a lamp voltage generation capacitor is limited to 5 volts/hikosecond, when a deflection voltage of 2 kilovolts is required for exposure operation, the exposure time is less than 400 picoseconds. can't get it.

Furthermore, depending on the design structure of the deflection plates 39, 40, 41, and 42 and the accelerating voltage of the electron beam, an appropriate amplitude difference and position are determined between the sweep voltage applied to the deflection plate 40 and the sweep voltage applied to the deflection plate 41. A phase difference may also be required.

Furthermore, in the above-mentioned Shatta tube 3, due to the electrode design for convergence and deflection, it is not possible to shorten the distance between the photocathode 33 and the anode plate 3B, which causes the need for a high acceleration voltage, and as a result, the deflection voltage is reduced. cannot be made smaller.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electron beam shutter tube that uses an electron beam shutter tube that operates at low voltage and can perform electron beam shutter operation at high speed.

Next, a detailed description will be given of an image tube type shutter tube, which is an embodiment of the electron beam beam tube according to the present invention.

FIG. 3 shows an image tube type shutter tube 6 of the present invention, in which a photocathode 63 is formed on the inner wall of a light entrance window 62 provided on the first bottom surface of a bottomed cylindrical vacuum-tight container 61. In contrast to the photocathode 63, a fluorescent surface 65 is formed on the inner wall of a light exit window 66 forming the second bottom surface of the vacuum-tight container 61.

The plate-like body 64 is provided between the photocathode 63 and the fluorescent surface 650 in parallel thereto.

The structure of the plate-like body 64 will be explained with reference to FIGS. 4, 5, and 6.

FIG. 4 is a view of the plate-like body 64 viewed from the front, that is, from the direction A-A in which the electron beam image is incident on the plate-like body 64 in FIG. The through holes 75...T5 are arrayed over the entire surface at as uniform intervals as possible, and electrodes 67 and 68 are provided at two opposing ends, respectively.

It is desirable that the material of the plate-shaped body 64 be strong, but as will be described later, when a voltage is applied between the electrodes 67 and 68, it is necessary to create a uniform potential gradient therebetween, so it is necessary to use a conductive material with relatively high resistance. It is desirable that the secondary electron emission ratio be small because it is necessary for the inner wall of the through hole 75 to absorb the collision electrons as much as possible when the electrons collide with the inner wall of the through hole 75.

Of course, the plate-shaped body 64 does not need to be made of a single material, so the base body is made of electrically insulating ceramic, and the inner wall of the through hole 75 has a relatively small secondary electron emission ratio and has sufficient conductivity. It is also possible to form a nickel or platinum layer having a nickel or platinum layer, and to form an extremely thin layer of molybdenum, which has a relatively high resistance, on the surface of the plate.

The easiest to make is one in which lead-containing glass tubes are bundled and fused together, and then the lead is reduced with hydrogen to create an appropriate resistance to air.

FIG. 5 is a sectional view taken along line BB in FIG. 4, and FIG. 6 is an enlarged view of portion C in FIG.

Next, the operation of the above-mentioned shatter tube will be explained.

In FIG. 3, the fluorescent surface 65 is connected to the power source 6 with respect to the photocathode 63.
9, 70, and 71, and the plate-shaped body 64 is kept at a high potential with respect to the photocathode 63 by connecting one electrode 6B to the contact between the positive electrode of the power source 71 and the negative electrode of the power source 70. The potential is maintained and the other electrode 67 is connected to the resistor 72.
The positive electrode of a power source 70 is connected to the connection point of the negative electrode of a power source 69 through a capacitor 74 to maintain a high potential with respect to the electrode 68, and to a fast ramp voltage generator 73 through a capacitor 74.

Therefore, before the high-speed ramp voltage generator 73 starts changing the output voltage, the electron beam emitted from the photocathode 63 enters the through hole 75 of the plate-like body 640, but due to the potential difference between the electrodes 67 and 68, the electron beam Since an electric field is generated in a direction perpendicular to the axis of the electron beam, the electron beam is deflected as shown by trajectory a shown in FIG. 6, collides with the inner wall of the through hole 75, and is absorbed.

If the inner diameter of the through hole 75 is 100 μm and the length is 5In1IL, it has an energy of 1000 eV, and since all the photoelectrons incident parallel to the through hole 75 collide with the inner wall of the through hole 75, there is a gap between the opposing walls of the through hole 75. 0.4 volt or more is required.

The diameter of the photocathode 53 is 10 mrIL, so the plate-shaped body 6
If the length of one side of 4, in other words, the distance between the electrodes 67 and 68, is 10IIt7n, the voltage applied between the electrodes 67 and 68 will need to be 40 volts or more.

When the voltage is 40 volts, the electron beam passes along trajectory b shown in FIG. 6, and when no voltage is applied, it passes along trajectory C shown in FIG.

Therefore, when the voltage of the power supply 70 is set at 100 volts and the fast ramp voltage generator 73 starts grounding the lamp voltage in the negative direction, the voltage of the electrode 67 changes from 40 volts to a negative 40 volts.
The optical image projected onto the photocathode 63 when the photocathode is between the bolts is reproduced on the fluorescent surface 65.

A. mentioned above. The image tube-type Shasta tube itself can change at high speed or obtain a still image of a moving object, but for this purpose, the speed of change of the voltage applied to the electrode is dependent on the speed of change or movement of the object. It must be thrown with a corresponding one.

However, since the aforementioned plate-shaped body is placed close to and facing the photocathode, no focusing electrode is required, and the energy of the electrons incident on the plate-shaped body is at most 1 kilovolt, and the plate-shaped body is adjusted accordingly. The voltage applied to the electrodes can also be lowered.

Moreover, it does not require a strict voltage.

In the embodiment of the invention described above, if the rate of change of the output voltage of the lamp voltage generator is 5 volts/picosecond, then 16
This gives picosecond exposure times.

This is 1/25th of the prior art example described above.

Above I explained about the image tube type Shasta tube.
The present invention can also be applied to an image orthicon tube type Shasta tube.

That is, in the imageorsicon tube type, a plate-like body having an appropriate electrical resistance between the photocathode and the storage target, a plurality of thin through holes perpendicular to the surface, and electrodes at two opposing ends is used. It may also be a shatter tube provided.

The structure of the image tube-type Shasta tube may be obtained by replacing the fluorescent surface with the storage target in the image tube-type Shasta tube described above.

It is sufficient to consider that the relative voltages applied to the two electrodes of the photocathode fluorescent surface and the plate-shaped body are the same.

Of course, at this time, it is desirable that the pulses applied to the electrodes of the plate-shaped body be synchronized with the vertical synchronization signal.

As described above, the electron beam shutter tube according to the present invention is a plate-shaped body, and electrodes are separately provided on any two opposing edges of the plate, and a uniform electric field can be applied to the area between the electrodes. Use an electron beam shutter device.

A plurality of perpendicular through holes are provided in the surface of the plate-like body of this electron beam shutter device, and the electron beam is swept between the two electrodes from one side to the other. By connecting a voltage source that applies a voltage that varies, it is possible to quickly cut off or limit the passage of the electron beam.

The electron beam that has passed through the electron beam shutter is converted into an image or an image signal on the surface that receives the electron beam.

The electron beam shutter tube according to the present invention, which can use the aforementioned fluorescent surface or storage target as a surface receiving the electron beam, is capable of absorbing a highly variable electron beam from a fluorescent surface caused by a rapidly changing or moving object. The electron beam shutter tube can be controlled at high speed with low voltage changes, and can be converted into a signal that can form a still image or still image on the surface that receives the electron beam.

A feature that allows a still image to be obtained without flowing in the direction of deflection is also obtained.

Since the length occupied by the electron beam shutter device in the tube axis direction is small, the electron beam shutter device can be configured to be relatively short.

Note that the electron beam shutter tube according to the present invention is not limited to the above-mentioned image tube type or image orthicon type C-shaft tube, but can be similarly applied to any vacuum tube that can form an electron beam image.

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional structural diagrams of a conventional shatter tube;
FIG. 3 is a cross-sectional structural diagram of a shutter tube according to an embodiment of the present invention, FIG. 4 is a front view of a plate-like body used in an electron beam shutter tube according to the present invention, and FIG. B sectional view, FIG. 6 is an enlarged view of portion C in FIG. 6... Shutter tube, 61... Vacuum-tight container, 62... Incident window, 63... Curved light surface, 6
4... Curved plate-like body, 65... Fluorescent surface, 6γ, 68
... Electrode, 69, 70, 71 ... Power supply, 72 ... Resistor, 73 - High voltage lamp voltage generator, 74 ... Capacitor, 75・・・・・・
Through hole.

Claims (1)

[Scope of Claims] 1. A vacuum-sealed container having a light entrance window, a photocathode provided on the inner surface of the entrance window, and a first surface facing the photocathode, through which electrons from the photocathode pass. A plate-shaped electron beam shutter is provided with a large number of through holes and electrodes on both edges to generate an electric field in a direction perpendicular to the through holes, and the electrons passing through the Tomiko beam shutter are converted into an image or an image signal. In order to convert the electron beam, photoelectrons generated at the electron beam receiving surface facing the emission surface of the electron beam shutter and the photocathode are accelerated in the direction of the electron beam shutter, and then passed through the electron beam shutter. An electron beam shutter tube comprising: an electric field generator for accelerating electrons in the direction of a surface receiving the electron beam; and a deflection electric field generator for generating a deflection electric field in an electrode of the electron beam shutter. 2. The electron beam shutter tube according to claim 1, wherein the surface receiving the electron beam is a fluorescent surface provided on a surface of the vacuum sealed container facing the photocathode.