JPS60150545A - High-speed frame shot camera - Google Patents

Abstract

PURPOSE:To allow a frame shot as a higher speed by providing a deflection means arranged so that the image-reformation position of a photoelectron image is located at the deflection center. CONSTITUTION:The first electron image forming section is constituted with electrode groups 6-10, amd a photoelectron image 5 generated on a photoelectric surface 4 passes the center in the tube axis direction of a deflection electrode 11 and is formed on the surface perpendicular to the tube axis. The deflection electrode 11 made with two parallel metal plates deflects the photoelectron beam from the photoelectric surface 4. A photoelectron beam blocking electrode 13 is provided with multiple openings 12 of a suitable shape to pass the photoelectron beam in sequence for a fixed time at each frame, set the exposure time T1, and illuminate the beam on a screen for that time. The second electron image forming section again forms the photoelectron image formed in the intermediate plate in the tube axis direction of the deflection electrode 11 and outputs it on each screen 16.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an electronic high-speed time-lapse camera with a short time interval and high shutter speed suitable for continuous shooting of objects and images whose shape and brightness change rapidly. .

(Prior art) In order to observe the temporal movement of a two-dimensional observation target,
High-speed cameras are used that operate high-speed shutters at short time intervals to obtain multiple time-lapse images.

Such cameras include mechanical high-speed cameras that mechanically rotate optical elements such as mirrors and prisms at high speed to obtain multiple time-lapse images, and mechanical high-speed cameras that obtain multiple time-lapse images by mechanically rotating optical elements such as mirrors and prisms. Electronic high-speed cameras are known that capture images for only that amount of time.

Generally speaking, the latter type of electronic high-speed camera can provide shorter imaging intervals and faster shutter speeds than mechanical high-speed cameras, so electronic high-speed cameras are better suited for rapidly changing imaging targets. A speed camera is suitable.

FIG. 1 is a sectional view showing a conventional electronic high-speed camera using an image tube.

First, the configuration and operation of the image tube in normal operation will be explained.

When a light image of the observation object l is imaged by the optical lens 2 on the photocathode 4 of the image tube, photoelectrons are emitted in accordance with the shape and brightness of this optical image.

The optical image of the object to be observed 1 is converted into a photoelectron image 5 in vacuum of the very surface of the photocathode.

Each part of the photoelectron image 5 has a number of electrons proportional to the brightness of each part of the optical image corresponding to that part, and the photoelectron image 5 is defined as a distribution of the number of these electrons.

A negative high voltage (■) is applied to the photocathode 4, and a negative high voltage (VM) is applied to the mesh electrode 6, but in a positive direction from the photocathode.

The photoelectron group forming the photoelectron image 5 is accelerated and moves in the direction of the mesoche electrode 6 due to the potential difference, and is transmitted through the mesoche electrode 6.

A negative high voltage from the positive side of the photocathode 4 is applied to the focusing electrode 107 , and OV (ground potential) is applied to the anode 108 , and the electrons that have passed through the mesh electrode 6 advance toward the deflection electrode 9 .

On the other hand, the conversion from an optical image to a photoelectron image at the photocathode 4 takes place in a time shorter than 1 picosecond, with a very high-speed response. Therefore, from time to time, photoelectron images corresponding to the shape and brightness of the optical image at each time are generated one after another on the surface of the photocathode 4, and the photoelectron groups that make up these images move toward the mesh electrode 6 one after another. , as a result, the photoelectron beam is transferred from the photocathode to the anno-F″1
08 along the tube axis.

In each cross section of the photoelectron beam perpendicular to the tube axis, two-dimensional information about the shape and brightness of the optical image at each time is converted into a spatial density of photoelectrons.

Also, when looking at the cross section along the tube axis from the deflection electrode to the photocathode side, two-dimensional information of the optical image at each time is sequentially included in each cross section from the front to the rear of the time. These will sequentially flow into the deflection electrode.

From these facts, it can be seen that a plurality of time-series time-lapse images can be obtained by sequentially arranging the information of each cross section on the fluorescent surface 111 so that they can be distinguished at appropriate intervals.

Note that the photoelectron group has various energies ranging from θ to several eV when emitted from the photocathode 4, and is emitted at various angles with respect to the photocathode.

Although this energy is lower than the energy obtained when the electron group is accelerated to the anode IO8, for example about 10 keV, the photoelectron group forming an arbitrary point on the photocathode 4, for example point A of the photoelectron image, is deflected. The question arises as to whether or not the light is being accelerated in the direction of the electrode 109 and spreading out, resulting in blur.

However, even if there are variations in the energy and direction of the photoelectrons, an appropriate voltage higher than the voltage on the photocathode is applied to the focusing electrode 107 to form an electron lens in this area, so that the electrons spread out. The electrons are focused to a corresponding point A on the fluorescent surface 111.

This is not a problem because it can be converged to .

The formation of this photoelectron image is shown in the figure using electron trajectories.

In the figure, p, p2 indicate the orbits of photoelectrons whose initial velocity is O among the photoelectrons generated at points A and B on the photocathode, respectively, and are called main orbits.

On the other hand, P)Z P2' is an angle of ±α with respect to the normal at points A and B of the photocathode, an arbitrary α of 0≦α≦90° in the orbit of something emitted with an energy of εoeV, and a photoelectron The trajectory of a photoelectron obtained by emission and having a small arbitrary value of ε0 of 0 to several eV is shown.

If a suitably adjusted voltage is applied to the focusing electrode 7, p,
The end points of 1 and P21 can be made to substantially coincide with points A' and B', respectively, where the main orbits collide with the fluorescent surface.

This also applies to any other point on the photoelectron image 5.

When the image tube is operated normally, the pair of deflection electrodes 109 are kept at ground voltage (OV), so the deflection electrodes 109 do not affect the electron trajectory. The group of photoelectrons that form an image on the fluorescent surface impact the fluorescent surface at high speed, producing light emission and producing an output image corresponding to the input optical image.

When the change in the input light image exceeds the response speed of the fluorescent material,
The images formed on the fluorescent surface 111 overlap and cannot be displayed as independent images.

Therefore, in normal operation, the range in which the movement of the input light image can be observed from changes in the output image is limited by the characteristics of the fluorescent material and the responsiveness of the eye.

Next, I will explain the time-lapse operation.

During normal image tube operation without time-lapse photography, as mentioned above, a direct current voltage (VK) is constantly applied to the photocathode 4.
OV is applied to the deflection electrodes 109a and 109b so that the deflection electrodes do not affect the electron trajectory. However, during the time-lapse operation, the voltage applied to the photocathode and the deflection electrode 109a or 109b is changed.

FIG. 2 shows the voltage on the photocathode and the deflection voltage applied to the deflection electrode during the time-lapse operation.

A rectangular wave pulse voltage train W1 is applied to the photocathode, and a step voltage W3 is applied between the deflection electrodes. First, attention will be paid to the photocathode 4 and the mesh electrode 6.

The same negative DC high voltage (VM) as in the above-mentioned normal operation is applied to the mesh electrode 6.

It is shown in FIG. 2(A) as W2 (=VM).

The photocathode 4 has a period 'r consisting of voltage VK'(VK'> VM) and voltage VK (VK < VM) (7).
Two square wave pulse voltages W1 are applied.

An electronic shutter action is performed based on the relationship between the voltage W2 (=VM) of the mesh electrode 6 and the voltage W of the photocathode 4 (VK'> VM > VK).

When the voltage W1 of the photocathode 4 is VK', it is higher than the voltage VM of the mesoche electrode 6, so the photoelectrons emitted from the photocathode 4 are repelled by the mesoche electrode potential, so that no output image is obtained.

When the voltage W1 of the photoelectron Wr4 is VK, it is lower than the voltage VM of the mesoche electrode 6, so the photoelectrons emitted from the photocathode 4 are accelerated by the mesoche electrode potential and emitted into the space of the focusing electrode 7.

The period T during which the voltage of the photocathode 4 is VK corresponds to the exposure time of a normal camera.

In the case of electron tubes, it is not light, so we will call it exposure time.

The period T2 of this rectangular wave pulse train W1 is an exposure interval (a time interval of stop-motion images obtained chronologically).

The deflection electrode 109b is maintained at OV (ground potential) as in normal operation, and a stepped voltage waveform W3 shown in FIG. 2(B) is applied to the deflection electrode 109a.

When the photoelectron beam passes through the deflection electrode 109, it is deflected in proportion to the applied deflection voltage and reaches the fluorescent surface 111.

FIG. 3 schematically shows the positional relationship of output images in the case of three-frame imaging.

The electrons corresponding to the light image reaching the space of the deflection electrode 109 at the time when the deflection voltage VD shown in FIG.
The image is formed at the position indicated by 11.

Similarly, when the deflection voltage VD2 (=O) is applied (time t2 to t2'), the electrons corresponding to the optical image reaching the space of the deflection electrode 109 are not deflected and are not deflected by the fluorescent surface shown in FIG. The image is formed at the position indicated by the output image (2) of 111.

Also, when the deflection voltage ■D3 is applied (from time t3 to
The electrons corresponding to the optical image reaching the space of the deflection electrode 109 at time t3') are imaged at the position indicated by the output image 3 of the fluorescent surface 111 in FIG.

These output images are recorded by an optical camera 113 shown in FIG. 1 with the shutter open, for example, from the time when these arrays begin until the time they end.

The above-mentioned exposure time T1 has the same important meaning as the exposure time in the case of a normal optical camera. Since the light image corresponding to the input light image continues to be emitted at the position,
These moving light images overlap, resulting in a blurred image.

Also, if T1 is too small, the light emission on the fluorescent surface will be
In an instant, the photoelectron beam carrying the remaining optical information is cut off, resulting in a dark output image. Therefore, considering the rate of change of the input light image, unless the image is blurred,
Choose a large T1.

In other words, the input light image is substantially stationary during the time T1 so selected.

The deflection electrode has the role of arranging photoelectron images corresponding to each exposure time on the fluorescent surface.

During this exposure time T1, the deflection voltage must be constant at least during that period in order to cause the photoelectron beam to flow into the same position on the phosphor surface.

A camera 113 records the luminescence of the fluorescent surface on film. In this example, three images are recorded.

In this way, it is possible to create a high-speed time-lapse camera that cannot be achieved with optical devices, but this device also has its limitations.

As described above, in the high-speed time-lapse camera, the deflection voltage VD applied to the deflection electrode 109a must be kept constant during the exposure time T1.

This is possible while the exposure interval T2 is large, but it is not easy to reduce T2 to less than a few Ions, for example.

Problems caused when the exposure interval T2 and exposure time T1 are shortened will be explained with reference to FIG. 4. In FIG. 4, W4 is a voltage corresponding to the voltage W1 applied to the photocathode 4 shown in FIG. 2(A), and W5 is a step voltage applied to the deflection electrode 109a shown in FIG. 2(-B). A voltage corresponding to voltage W3 is shown.

The waveform W5, which should be a staircase waveform, becomes distorted as shown in the figure, and the output image becomes blurred.

If the exposure time T1 is a very small value of several ions or less, the waveform W4 applied to the photocathode will also become dull, as shown in the waveform W4 in FIG.

If the photocathode potential is more negative than the mesoche electrode potential, the photoelectron beam passes through the mesoche electrode and causes the fluorescent surface to emit light.

Therefore, as shown in Fig. 4, the photocathode voltage (VK
), even when the voltage of the waveform in the middle slope part is not equal to
Makes the fluorescent surface emit light.

On the other hand, an electron lens correctly forms a photoelectron image on a fluorescent surface only when the photocathode potential is equal to VK; otherwise, the image is blurred.

Therefore, with such a waveform, the output image will be blurred.

Furthermore, even with such a corrupted waveform, W4 is several 10
~ several hundred volts (7) amplitude, W5 requires a voltage of 1 to 2 kV for the entire height with a step difference of several tens to several 100 volts.

Therefore, when "r'1.T2 is smaller than several tens of ns, it is impossible to construct a circuit that generates an ideal voltage as shown in FIG. 2.

(Object of the Invention) An object of the present invention is to provide a high-speed time-lapse camera based on a novel principle that enables higher-speed time-lapse photography.

(Description of Configuration) In order to achieve the above object, a high-speed time-lapse camera according to the present invention is a high-speed time-lapse camera that uses an image tube to take time-by-time pictures of an image formed on a photocathode, and re-forms a photoelectron image. a first electron lens arranged such that the image re-imaging position of the photoelectrons becomes the center of deflection; a plurality of second electron lenses disposed toward the deflection center; a plurality of fluorescent surfaces disposed at respective imaging positions of the second electron lenses; and a lens drive that supplies operating power to each of the electron lenses. and a deflection means driving circuit that supplies operating power to the deflection means.

Furthermore, in order to ensure more reliable operation, in the above configuration, the deflection means drive circuit supplies operating power to the deflection means to generate a deflection whose degree of deflection is time-gradient, and the starting circuit provides the following: The deflection means driving circuit is configured to detect light emission from the observation target and activate the deflection means drive circuit in synchronization with the light emission.

The high-speed time-lapse camera has a photocathode and a fluorescent surface.

An image tube having an electrode group having an electron lens function, a deflection electrode, etc. can be modified and configured.

When the deflection means is constituted by electrostatic deflection means and a gradient voltage is applied as the deflection voltage, a gradient voltage as shown in FIG. 5 is applied between the electrodes.

For high-speed time-lapse photography, it is necessary to make changes at very high speeds.

This deflection voltage can be created using an avalanche transistor or an electron tube.

Electron beams that have passed through a specific portion of this gradient voltage are sequentially taken out by a second electron lens group to perform frame-by-frame photography.

The shank operation using a mesh electrode as in the conventional device is no longer necessary, and the exposure time T1 and exposure interval T2 are reduced to several I
Even at Qns, there is no blur and reliable high-speed frame-by-frame photography is possible.

(Description of Examples) Hereinafter, the present invention will be described in more detail with reference to the drawings and the like.

FIG. 6 is a sectional view including the tube axis showing an embodiment of the electron tube of the high-speed time-lapse camera according to the present invention.

In terms of function, the structure inside the airtight container kept at high vacuum is the first electron image forming section, the shank operation section of the photoelectron beam (that is, the operation that determines the exposure time), and the output phosphor surface of the output photoelectron image. 3 of the second electronic image forming section
It can be considered in two parts.

The first electronic imaging portion forms part of the hermetic wall and receives the input optical image through an input hermetic window 3. A photocathode 4 provided on this inner surface for converting an input optical image into a photoelectron image. It is formed of a group of electrodes for focusing the photoelectron image 5 generated on the photocathode on a plane that passes through the center point of the deflection electrode 11 in the tube axis direction and is perpendicular to the tube axis.

The electrode group includes axially symmetric mesh electrodes 6. which are sequentially arranged along the tube axis perpendicular to the center of the photocathode 4. 1st
Focusing electrode7. A first anode 8 with an aperture in the middle
．． An electron beam angle adjustment electrode 9° for adjusting the angle of the photoelectron beam when it flows into the deflection electrode and the input section of the second electron image forming section, which will be described later.A deflection electrode 11 disposed close to the electron beam angle joint electrode 9. The electric field formed by each electrode is shielded so that the potentials of the electrodes do not adversely affect each other.
It also includes a shielding electrode 10 having an aperture in the center for transmitting the photoelectron beam.

The shutter operation of the photoelectron beam and the arrangement of the output photoelectron image on the output phosphor surface are performed by arranging the photoelectron image on each output screen portion, which will be described later, and photographing each frame (one frame of photography). It functions to provide exposure for a set amount of time. A portion for shuttering the photoelectron beam and arranging the output photoelectron image on the output phosphor surface includes a deflection electrode 11 and a photoelectron beam blocking electrode 13 having a plurality of appropriately shaped apertures.

A deflection electrode 11 made of two parallel metal plates deflects the photoelectron beam from the photocathode 4 .

The photoelectron beam blocking electrode 13 has an opening of an appropriate shape for sequentially passing the photoelectron beam for a predetermined time in each frame, setting an exposure time T1, and irradiating the beam onto the screen for that time. A plurality of holes are provided.

The plurality of apertures 12 are arranged along a strip-shaped path along which the photoelectron beam is deflected, such that the center of the aperture 12 is on the center line of the path. The shape of the opening 12 may be circular or rectangular with one side parallel to the plane of this cross section and the other side perpendicular to this cross section.

When the beam is swept, the time it takes to cross this aperture is the exposure time T1 of the electron image, and the time from the center of the aperture to the center of the next aperture is the exposure interval T2, which will be discussed later. This is explained in detail in the operation section.

The surface of each aperture in the photoelectron beam blocking electrode 13 is arranged perpendicularly to the electron beam reaching it, and is normally formed by a straight line connecting the center of the adjacent aperture 12 and the center of the deflection electrode 11. The number of apertures arranged at equal angles prevents the photoelectron beam from getting caught on the edge of the deflection electrode, and the arrangement of the electrode group for forming an electron lens, which is further connected after the aperture 12, is spatially unreasonable. It is possible to line up as many as necessary as long as it is not. The center of the deflection electrode 11 and each opening 12
The distances up to 12, . . . are arranged equally.

The number of openings 12 corresponds to the number of frames.

This embodiment is a camera that has three apertures lined up and takes three frames.

The second electron image forming section forms again an image of photoelectrons formed in a plane in the middle of the deflection electrode in the tube axis direction, and outputs the image onto each screen 16.

A second electronic image forming section is provided for each aperture.

The second electron image forming section includes a second focusing electrode 14, a second anode 15, . and a screen 16 consisting of a coated fluorescent surface. It is formed from an output airtight window 17.

FIG. 7 is a block diagram showing the overall configuration of the high-speed time-lapse camera according to the present invention.

The electron tube part was explained in detail earlier in Figure 6, so
It is shown schematically.

The optical lens 2 is a lens for forming an image of the object 1 to be observed on the photocathode 4 .

A half mirror 21 is arranged between the lens 2 and the photocathode 4 to guide a portion of the light from the object 1 to be observed downward.

This light is passed through another lens 22 to a high-speed photodetector P
23 INlN diodes are bundled.

The output of the jIN diode 23 is delayed by an arbitrary time in a delay circuit 24 and connected to a ramp voltage generation circuit 25. The PINlN diode 23 extension circuit 24 activates the ramp voltage generation circuit 25 that drives the deflection electrode 11, which is the deflection means.

The slope of the gradient voltage is appropriately determined depending on the desired time-lapse interval or exposure time of the time-lapse image to be observed.

The starting circuit triggers the start of the sweep of the ramp voltage that determines which time images are displayed on the output screen.

An operating voltage is supplied from a DC high voltage generating circuit 40 to the electrodes of the first electronic image forming section and the second electronic image forming section described above.

The voltages and voltage changes of each part will be described later along with the operation.

Next, the operation of the apparatus of the embodiment will be explained.

An optical image of an object to be observed 1 whose brightness and shape change rapidly through an optical lens 2 is incident on a photocathode 4 and formed into an image through an airtight window 3.

The response speed of the photocathode 4 is faster than 1 picosecond, and this optical image is converted into a photoelectron image with a very fast response.

The operating voltage from the DC high voltage generation circuit 40 is -10 kV to the photocathode 4, and -8 to the nearby mesoche electrode 6.
, 5 kV is applied. As a result, the electron group forming this photoelectron image is accelerated in the direction of the mesoche electrode 6.

On the other hand, since the photocathode 4 is continuously irradiated with light, photoelectrons are generated one after another, and a photoelectron beam is generated from the photocathode 4 toward the deflection electrode 11 along the tube axis. In each cross section of the photoelectron beam perpendicular to the tube axis, two-dimensional information about the shape and brightness of the optical image at each time is converted into a spatial density of electrons.

When looking at the cross section along the tube axis from the deflection electrode 11 to the photocathode 4 side, the information at each time is sequentially entered from earlier to later. It flows towards the deflection electrode 11.

The photoelectron image 5 becomes blurred as it flows, but by applying an appropriate voltage to the first focusing electrode 7, the photoelectron image is formed on a cross section that passes through the center point of the deflection electrode 11 in the tube axis direction and is perpendicular to the tube axis. image again as

Figure 8 shows the above-mentioned electron optical system replaced with a geometric optical system, and shows the state of image formation represented by the trajectory of the electron group forming points A and B of the photoelectron image. be. The main orbit of photoelectrons from each point is indicated by 20.

The orbits shown on both sides of each main orbit are - of points A and B.
This is the orbit of a photoelectron emitted with an arbitrary energy at an arbitrary angle with respect to the normal to the photocathode, and this orbit is hereinafter referred to as a β orbit.

Although the main orbit 20 can actually be drawn for each point of the optical image projected on the photocathode, only the one corresponding to points A 1 and B is shown here.

The angles at which these main orbits enter the deflection electrode 11 and the aperture 12 are adjusted by the electron lens 19 so that they are approximately parallel or slightly narrower. It is well known that electron lenses can adjust the divergence angle of their main orbits. Electronic lens 18 shown in FIG. electronic lens 1
9 is mainly the first one shown in FIG.
The focusing electrode 7° is made by the electron beam angle adjusting electrode 9. In this example, the electron lens 18 has a voltage of -8,5kV.
Mesoche electrode to which 6. -8.8 kV applied to first focusing electrode 7. The electron lens 19 is formed by the first anode 8 to which a ground voltage of 0■ is applied, and the electron lens 19 is formed by the first anode 8 to which a ground voltage of OV is applied. Electron beam angle adjustment electrode 9. -7 was applied with ■. Shield electrode 10 to which OV is applied
formed by.

An electron image is formed on a plane that passes through the center point of the deflection electrode 11 in the tube axis direction and is perpendicular to the tube axis, and the main orbit group is approximately parallel to or narrows to the deflection electrode 11 and the aperture 12. The reason for the incidence will be described in detail in the following explanation of the arrangement of photoelectron images and the operating section of the shutter section.

As described above, the photoelectron beam incident on the intermediate plane of the deflection electrode 11 is swept over the surface of the photoelectron beam blocking electrode 13 by the deflection voltage applied to the deflection electrode 11.

Figure 9 shows the deflection voltage. In the figure, 12a and 12b indicate ramp voltages applied to the deflection electrodes 11a and llb, respectively.

In this embodiment, as shown in FIG. 9, symmetrical deflection voltages are applied to both deflection electrodes, but of course, one deflection electrode is fixed at 0, and only one is applied. It is also possible to deflect the photoelectron beam by applying a gradient voltage.

The deflection electrode has a width of 2 cm, a length in the tube axis direction of 2 cm, and an interval of 1 cm. The photocathode 4 has a voltage of -10 kV.

When the shielding electrode lO is set to the ground potential, the photoelectrons are accelerated to an energy of 10 kV and enter the deflection electrode 11.

The photoelectron beam incident on the deflection electrode 11 is deflected only by a force perpendicular to the tube axis.

Since the speed in the direction of the tube axis does not change even after entering the deflection electrode, at a speed corresponding to an energy of 1QkeV, the time it takes to pass through the length of 2 cm in the direction of the tube axis of the deflection electrode 11 is approximately It is 340p3.

When a photoelectron beam is deflected by this deflection electrode 11, the deflection voltage applied to the deflection electrode can be considered to be constant while the photoelectron beam passes through this deflection electrode, or it may change greatly during that time. The appearance differs depending on how drastic the change in the deflection electrode is.

First, the former case will be explained, and then the latter case will be explained.

In the deflection voltage waveform shown in FIG. 9, T is, for example, 1000 ns.
In this case, no matter where on the inclined part the photoelectron beam is incident, at a speed equivalent to 10 keV, the deflection voltage can be considered constant while it passes through the deflection electrode.

If we take the point where the slope of the slope voltage starts at time 0 as shown in FIG.
A voltage of +500V and -500V is applied to these, respectively.

How the photoelectron beam incident on the deflection electrode is deflected when this voltage is applied will be explained with reference to FIG.

Here, the arrow indicated by the h line at the intermediate plane of the deflection electrode in the tube axis direction indicates that the deflection voltage applied to the deflection electrode 11 is 0.
It shows the formation of a photoelectron image in case (2) (deflection electric field is 0).

The three dotted lines incident on the lower end of the arrow, point M, on the left side of this arrow indicate how the main orbit and β orbit are imaged at point M when the deflection voltage is 0, and the electric field is 0. Therefore, it goes straight from the entrance of the deflection electrode to point M.

The subsequent trajectory when the deflection voltage is O is not shown, but in that case, the photoelectron beam continues to travel straight and the image becomes blurred again. Actually, +500■ to the deflection electrode 11a,
Since -500 V is applied to the deflection electrode 11b, when the photoelectron beam is incident on the deflection electrode, the photoelectron beam is bent to draw a parabolic trajectory as shown by the solid line in the figure.

When the photoelectron beam leaves the deflection electrode 11, since the tube wall electrode 30 and the photoelectron beam blocking electrode 3 are at O2 (ground potential), the electric field becomes O again, and the photoelectron beam travels straight. What can be confirmed by simple calculations is that, as shown in Figure 10, after passing through the deflection electric field, the trajectory is tilted in a straight line, and the trajectory is reversed as shown by the dotted line toward the deflection electrode. When extended, both the main orbit and the β orbit coincide with the M point.

This is an example in which a voltage of +500 cm is applied to the deflection electrode 11, and other voltages are applied at other times as shown in FIG.

At this time, the position and inclination of the photoelectron beam after exiting the deflection electrode 11 are different from those at +500■, but if the trajectory after changing to a straight motion is extended in a straight line in the opposite direction, the main trajectory is , it can be confirmed that both the β orbits coincide with the M point.

This means that after the photoelectron beam passes through the deflection electrode and moves in a straight line, no matter how the photoelectron beam is deflected when viewed from the output side of the tube, when the deflection electric field is 0, it will be focused, for example, at point M. The beam that has traveled from point M,
This shows that the radiation can be regarded as if it were radiated in a straight line.

In the above, the explanation has been made using point M, but of course this also applies to any point other than point M indicated by the arrow.

This principle makes it possible to realize a novel configuration of the present invention.

Furthermore, a simple calculation shows that the deflection voltage is 0.
When a photoelectron beam is incident on a surface other than the intermediate plane of the deflection electrode to form a photoelectron image, the photoelectron beam (main orbit and β orbit) that diverges from any point on the image is deflected by the deflection electrode and further When viewed from the right side of the deflection electrode, each deflection voltage appears to be radiated from a single point, which is the reverse extension of the trajectory after passing through the deflection electrode and moving in a straight line. However, that point is at a different location when the deflection voltage is different, and it depends on how the photoelectron beam is deflected when it is incident so that the photoelectron image is formed on the intermediate plane of the deflection electrode. However, when viewed from the right side of the deflection electrode,
It does not appear to be radiated from a single point.

This is the reason why the photoelectron image is formed on a cross section perpendicular to the tube axis at the center of the deflection electrode in the tube axis direction.

Also, in the deflection voltage waveform shown in FIG. 9, T is, for example, 1.5 ns.
In this case, since the time required for the photoelectron beam to pass through the deflection electrode is about 340 ps, the voltage applied to the deflection electrode changes.

In this case, when the deflection voltage is O, the photoelectron image generated on the photocathode is deflected so that it passes through the middle of the deflection electrode in the tube axis direction and is re-imaged on a cross section perpendicular to the tube axis. It turned to the side.

As a result, when the deflection voltage is O, the main orbit and β orbit that diverge from an arbitrary point Q where the photoelectron image is formed on the intermediate plane exit the deflection electrode and move in a straight line. Then, if we extend that straight line in the opposite direction, no matter what time the gradient voltage waveform is incident on, it will lead to a specific point on the cross section perpendicular to the tube axis and at the midpoint of the deflection electrode in the direction of the tube axis. This point is a point shifted in the opposite direction to the direction in which the photoelectron beam is swept by a certain distance d from the imaging point Q when no electric field is applied to the deflection electrode in the intermediate cross section. Understood.

The value of the specific ratio Md is determined by the length of the deflection electrode 11, the speed of the photoelectron beam in the tube axis direction, and the temporal change rate of the deflection voltage.

From the above, even when the photoelectron beam is deflected so quickly that the value of the deflection voltage changes greatly while the photoelectron beam passes through the deflection electrode, and in which direction the photoelectron beam is deflected, the deflection The photoelectron image is located at a position moved by d from the photoelectron image formed when the voltage is 0 in the direction opposite to the direction in which the photoelectron beam is swept within the imaging plane, which is the midpoint in the direction of the tube axis of the deflection electrode. , it can be regarded as if the photoelectron beam were emitted in a straight line from there.

In this way, even though a gradient voltage is applied to the deflection electrode and the photoelectron beam moves on the cross section of the aperture of the photoelectron beam blocking electrode 13 shown in FIG. The photoelectron beam can be treated as being emitted in a straight line from the photoelectron image.

This means that if the photoelectron beam is incident on the electron lens 21 whose diameter is within a range where spherical aberration can be ignored, the electron lens 21 will be able to move around the virtual state even though the photoelectron beam is moving and sweeping the lens. This means that a static image can be formed on the output screen.

In this case, we can consider that the deflection voltage does not change during the time the photoelectron beam passes through the deflection electrode.
This is shown in beams i, n, and m in FIG.

These are shown for a photoelectron beam consisting of a main orbit and a β orbit in which, when the deflection voltage is 0, a group of electrons forming point B of the photoelectron image 5 on the photocathode is imaged at point M on the intermediate plane of the deflection electrode. The photoelectron beam is deflected by the deflection electric field in the sweeping direction shown by the arrow in the figure. n, III
However, any photoelectron beam can be treated as being emitted in a straight line from point M, and is imaged by the electron lens 21 at point -M'.

Note that the beams ■ and ■ have passed through the aperture 12 just at their two ends, and the sweep time from the beam I to the position of ■ becomes the exposure time.

Eventually, the photoelectron beam for point B is imaged at point M′ for all of its exposure time, and any other point of the photoelectron image,
For example, point A is similarly imaged at point N'.

Even if the deflection voltage changes while the photoelectron beam passes through the deflection electrode, the photoelectron image indicated by the MN point in the deflection electrode in FIG. 8 can be shifted upward by d using the electron lens 21. The result is the same as that obtained by imaging.

This means that without applying a stepped voltage to the deflection electrode,
Even with a gradient voltage, there is no blurring on the output phosphor surface caused by the movement of the image due to the deflection electric field, and the same effect can be obtained as applying a stepped voltage to keep the image stationary on the phosphor surface during the exposure time. Show that you can give.

Further, the time required for the photoelectron beam deflected by the deflection electrode to cross the aperture 12 on the photoelectron beam blocking electrode 13 determines the exposure time.

In addition, the electron lens 19 is used to suppress the divergence of the main orbits and make the main orbits incident on the deflection electrode parallel or slightly narrower, since the main orbits are spread out by the time they flow into the blocking electrode with an opening. In addition, the length of the aperture in the sweep direction must be increased and the pitch of the aperture must be widened, making it impossible to take a large number of frames, and the diameter of the aperture of the electronic lens 21 must also be increased. Otherwise, spherical aberration will increase.

The above explanation has been made regarding any one opening on the photoelectron beam blocking electrode 13, but the same applies to other openings.

The exposure interval is the sweep time of the photoelectron beam from the center of one aperture to the center of another adjacent aperture.

The second electronic image forming section is composed of an electronic lens 21 and an output fluorescent surface 16 shown in FIG.

The electron lens 21 includes a photoelectron beam blocking electrode 13 (ground potential), a second focusing electrode 14 (-8kV), and a photoelectron beam blocking electrode 13 (ground potential) shown in FIG.
It can be formed as the second anode 15 (OV, ground potential). These are prepared for each aperture 12, and the number of apertures corresponds to the number of frames.

Since the electron optical system is configured as described above, as shown in FIG. 7, a part of the light from the observation object 1 is detected by the starting circuit, and a gradient voltage is generated by the gradient voltage generation circuit. As a result, 16 images with extremely short exposure times can be sequentially taken out on each screen.

Comp2 (Modification) The first and second electron lenses of the embodiment described in detail above can be changed to a magnetic field focusing type coil shown in FIG. 11.

The action of the electronic lens 18 in FIG. 8 is performed by the first focus coil 31, and the action of the electronic lens 21 is performed by the first focus coils 32, 32.32.

In addition, in the example, an example using the mesh electrode 6 was shown, but
Although this electrode is not essential, if the mesh electrode 6 is not used, the exposure time and exposure interval are limited to several tens of ps. Similarly, the photoelectron beam angle adjusting electrode 9 may not be provided2, but in that case, the size and interval of the apertures will be significantly large, and the device will be large.

Furthermore, although a deflection electrode consisting of two parallel flat plates is used in the embodiment, deflection electrodes shown in FIGS. 12(A) and 12(B) may also be used. This electrode increases the deflection sensitivity and also prevents the photoelectron beam from being stranded on the output side.

When using these deflection electrodes, the question is which position of the deflection electrode in the direction of the tube axis should the photoelectron image pass through to connect it to the cross section perpendicular to the tube axis? This position varies depending on the shape of the deflection electrode in the tube axis direction, and is more generally referred to as the deflection center, including the previous embodiments. As shown in Figure 12, the deflection center is the point where a photoelectron beam aligned with the tube axis enters the deflection electrode, is bent in a curved line within the deflection electrode, exits the deflection electrode, and then moves in a straight line. , if we extend the rectilinear motion part as it is in the original direction in which the beam traveled, and also extend the straight line that is incident on the deflection electrode in line with the tube axis, the deflection will be as shown in Figure 12. They always intersect (no matter how deflected) at the point P defined by the electrodes. This point is always the same regardless of whether the amount of deflection is large or small, and when viewed from the output side of the deflection electrode, it appears as if the beam was deflected linearly from that point, so it is called the center of deflection. A photoelectron image may be formed on a cross section perpendicular to the tube axis that includes this point P.

(Explanation of Effects) As explained in detail above, the high-speed time-lapse camera according to the present invention can separate images and determine the exposure time on the side of the plurality of second electron lenses, so unlike conventional devices, the shutter action by the mesh electrode can be determined. There is no need to apply the shutter voltage to the mesh electrode, and the problem of rounding of the shutter voltage applied to the mesh electrode can be completely solved.

Further, as a dynamic applied voltage used for photoelectron beam exposure and arrangement of a plurality of time-lapse images according to the present invention, only one or one set of gradient voltages may be applied without using a complicated operating voltage waveform.

In the conventional method, there was a phenomenon in which the output image was blurred due to an exposure time and exposure interval shorter than several IQns, but such a problem does not occur with the high-speed stop-motion camera according to the present invention.

[Brief explanation of drawings]

FIG. 1 is a sectional view including the tube axis showing a conventional high-speed time-lapse camera. FIG. 2 is a waveform diagram showing changes in the voltage applied to the me-noche electrode and the deflection electrode of the high-speed time-lapse camera. FIG. 3 is a schematic cross-sectional view for explaining the operation of the high-speed time-lapse camera. FIG. 4 is a waveform diagram for explaining the droop of the mesoche electrode and the deflection electrode that is expected at the high speed limit of the high speed time-lapse camera. FIG. 5 is a graph showing changes in the voltage applied between the deflection electrodes of the high-speed time-lapse camera according to the present invention. FIG. 6 is a sectional view including the tube axis showing an embodiment of the high-speed time-lapse camera according to the present invention. FIG. 7 is a block diagram showing the overall configuration of the high-speed time-lapse camera according to the present invention. FIG. 8 is an explanatory diagram for explaining the electron optical system of the embodiment. FIG. 9 is a waveform diagram showing the voltage applied to the deflection electrodes of the embodiment. FIG. 10 is a diagram showing the path of the electron beam in the deflection electrode of the embodiment. FIG. 11 is a sectional view including the tube axis showing still another embodiment of the high-speed time-lapse camera according to the present invention. FIG. 12 is a schematic diagram showing a modification of the electrostatic deflection means. 1... Observation object 3... Input airtight window 4... Photocathode 5... Photoelectron image 6... Mesoche electrode 7... First focusing electrode 8...
First anode 9... Adjustment electrode 10... Shield electrode
DESCRIPTION OF SYMBOLS 11... Deflection electrode 12... Opening 13... Photoelectron beam blocking electrode 14... Second focusing electrode 15... Second anode 16... Screen 17... Output airtight window 21...・Half mirror 22...Lens 23...PIN diode 24...Delay circuit 25...Slope voltage generation circuit 40...DC high voltage generation circuit Patent applicant Hamamatsu Photonics Co., Ltd. Agent Patent attorney Inoro Arrogance? Figure (A) (B) Condolence ρ Figure bud fil El (A') ('3) Digit f0 Nursery procedure amendment form 1. Display of the case Patent Application No. 5454 of 1982 2, Name of the invention High-speed time-lapse camera 3, Person making the amendment Relationship to the case Patent applicant 4, Agent Contents of the amendment (Patent Application 1982-5454) (1) "Deflection electrode 9" on page 5, line 5 of the specification is corrected to "deflection electrode 109." (2) 1 arbitrary ε on page 7, line 12 of the specification. " is corrected to "any 60". (3) "Focusing electrode 7" on page 7, line 14 of the specification is corrected to "1 focusing electrode 107". (4) "Focusing electrode 7" in the first to second lines of page 10 of the specification is corrected to "focusing electrode 107". (5) [10] from line 14 to line 15 on page 25 of the specification
Correct kVj to rlOkeVJ. (6) "Main startup" on page 34, line 2 of the specification is "main orbit"
Correct to. (7) Delete rcomp2 J on page 35, line 6 of the specification. (8) "1st focus coil 32" on page 35, lines 10 to 11 of the specification is replaced with "second focus coil 3".
2”. that's all

Claims (1)

[Scope of Claims] +11 In a high-speed time-lapse camera that uses an image tube to capture images formed on a charging surface, a first electron lens that re-images a photoelectron image; and a first electron lens that re-images the photoelectron image. a deflection means arranged so that the position is the deflection center; and a plurality of second electron lenses arranged with their central axes facing the deflection center so as to sequentially receive the electron beams deflected by the deflection means. a plurality of fluorescent surfaces respectively arranged at the imaging positions of the second electron lens; a lens drive circuit that supplies operating power to each of the electron lenses; and a deflection means drive that supplies operating power to the deflection means. A high-speed frame-by-frame camera composed of circuits. (2) The high-speed stop-motion camera according to claim 1, wherein the first or second electron lens is of an electrostatic focusing type or an electromagnetic focusing type. (3) In a high-speed time-lapse camera that uses an image tube to capture an image formed on a photocathode, a first electron lens that re-images a photoelectron image and a position where the photoelectron image is re-imaged are deflected. a plurality of second electron lenses arranged with their central axes facing the deflection center so as to sequentially receive the electron beams deflected by the deflection means; a plurality of fluorescent surfaces respectively arranged at the imaging positions of the second electron lens; a lens drive circuit that supplies operating power to each of the electron lenses; A high-speed time-lapse camera comprising a deflection means driving circuit that supplies operating power to be generated, and a starting circuit that detects light emission from an observation target and starts the deflection means in synchronization with the light emission. (4) The high-speed stop-motion camera according to claim 3, wherein the plurality of second electron lenses are arranged corresponding to the plurality of degrees of deflection of the deflection means. (5) A patent in which the activation circuit includes a photodetector and a delay circuit that delays the detection output, and by adjusting the amount of delay of the delay circuit, multiple frames can be made to correspond to arbitrary points in the observation target. A high-speed stop-motion camera according to claim 3.