JPH022263B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method for operating a scan conversion type storage tube used in a storage oscilloscope, an A-D converter, etc. Concerning the method of operation of the tube.

Prior Art A scan conversion type storage tube that can apply an electrical signal to a deflection plate, write a waveform corresponding to the signal onto a storage target using an electron beam, and read out the stored waveform as an electrical signal if necessary. Scan converter tubes are known. Furthermore, as schematically shown in FIGS. 1 and 2, Japanese Patent Application Laid-Open No. 55-1066 discloses that a single collector electrode 2 is provided on an insulating single crystal substrate 1, and a single collector electrode 2 is provided on an insulating single crystal substrate 1. A storage target is disclosed in which electron-hole pairs are generated by bombarding the storage layer or storage region made of the material with an electron beam, and these are utilized for writing to improve the writing speed.

By the way, when writing signals to the storage targets shown in FIGS. 1 and 2, for example,
As shown in Publication No. 50558, in order to obtain a prime state, first, the potential of the collector electrode 2 is set to a first crossing potential at which the amount of secondary electron emission δ (number of secondary electrons/number of primary electrons) becomes 1. Set the value above (for example, 2350V to the cathode) and bombard the target with an electron beam. As a result, the potential of the storage surface 3 on the surface of the substrate 1 becomes 2350V, which is the same as the potential of the collector electrode 2.
Next, in order to obtain the erase potential difference V _E , the potential of the collector electrode 2 is set to below the first crossing potential, for example, +10 V selected from the range of +10 to +30 V with respect to the cathode, and bombarded with an electron beam again. The storage surface 3 is brought to the same potential as the cathode. As a result, an erase potential difference of 10 V is generated between the storage surface 3 and the collector electrode 2.

Next, in order to write a signal to the storage target, the potential of the collector electrode 2 is set to be higher than the first crossing potential, for example 10 kV with respect to the cathode, and a beam is selectively projected onto the storage target in accordance with the signal.
As a result, the writing part (beam impact part) has a potential of, for example, 9991V with respect to the cathode (-9V with respect to collector electrode 2), and the non-writing part has a potential of, for example, 9991V (-9V with respect to collector electrode 2).
It is maintained at 9990V (-20V with respect to the collector electrode 2) which is obtained by subtracting the erase potential difference of 10V from 10kV, and a charge pattern of -9V and -10V is formed with respect to the collector electrode 2.

Next, at the time of reading, the collector electrode 2 is set to, for example, +5V with respect to the cathode. As a result, the potential of the written portion becomes -4V with respect to the cathode, while the potential of the non-written portion becomes -5V (with respect to the cathode). Now, if raster scanning is performed with an unmodulated electron beam when the beam cutoff voltage at the target is -5V, the electron beam will reach the -4V written area, and the electrons will reach the -5V non-written area. The beam does not reach them, making it possible to distinguish between them and read them.

However, in the conventional method, it is necessary to write after obtaining the erase potential difference _VE through the prime operation and the erase operation, and it has been impossible to start writing quickly. In addition, since a voltage lower than the first crossing potential is applied to the collector electrode during reading, it is required to change the voltage significantly between writing and reading.
It was difficult to quickly switch the voltage. The above-mentioned problem similarly occurs in a target whose storage layer is an amorphous insulator such as glass or a polycrystalline insulator such as SiO ₂ .

OBJECTS OF THE INVENTION It is, therefore, an object of the present invention to provide a method of operating a scan conversion type storage tube that can shorten the write and read cycles.

Structure of the Invention To achieve the above object, the present invention provides a plurality of storage substrates made of an insulating material such as a single crystal, a polycrystal, or an amorphous material such as glass, preferably having a resistivity of 10 ¹² Ω·cm or more. When an electric signal is written by deflecting and projecting an electron beam onto a storage target having a structure in which the collector electrodes of the plurality of collector electrodes are arranged in parallel with each other in an electrically insulated state, and then read, the plurality of collector electrodes and the base body are 2 to at least two adjacent collector electrodes of the storage target that have substantially no potential difference between them and the storage surface.
Applying voltages that are higher than the first crossing voltage at which the second electron emission rate becomes 1 and different from each other, and maintaining the applied state of the different voltages, selectively bombard the storage target with an electron beam to generate an electric signal. writing, then applying substantially the same voltage higher than the first crossing potential to the plurality of collector electrodes, and scanning the storage target with an unmodulated electron beam while maintaining the same voltage application state to write. The present invention relates to a method of operating a scan conversion type storage tube characterized by reading signals.

Effects According to the above invention, since a plurality of collector electrodes are provided and different voltages are applied to generate a potential difference between the collector electrodes, writing is possible even when the erase potential difference is substantially zero. Furthermore, since a voltage higher than the first crossing potential is applied to the collector electrode during reading, the width of voltage change when switching the mode from writing to reading becomes small, allowing rapid switching. Further, since reading is performed at a voltage higher than the first crossing potential, destructive reading is performed, and when reading is completed, the collector electrode and the storage region are at substantially the same potential, and writing becomes possible immediately. Furthermore, even when erasing is performed before writing, it is not necessary to apply an erase potential difference, so only the prime mode is sufficient, and the erasing time can be significantly shortened.

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

First Embodiment (Figs. 3 to 6) The storage target 4 according to the first embodiment shown in principle in Figs. 3 to 4 is a sapphire single crystal substrate 5 which is an insulating single crystal. A first collector electrode 6 and a second collector electrode 7 electrically separated from each other are provided on one flat main surface. Since the sapphire single crystal substrate 5 is an electrical insulator, if the first and second collector electrodes 6 and 7 are placed separately, they are electrically insulated. 1st and 2nd
The collector electrodes 6 and 7 are made by depositing metal such as chromium (Cr) to a thickness of 0.05 μm to several μm, and are formed into a comb-shaped shape using photoresist technology.
It has linear portions 6a and 7a of about 0.5 μm to 50 μm, respectively. The linear portions 7a of the second collector electrode 7 are inserted between the linear portions 6a of the comb-shaped first collector electrode 6, and the linear portions 6a, 7a are arranged alternately in parallel. Therefore, the electrode pattern in the target effective area is striped. A part of the accumulation surface 8 of the filament, that is, the surface of the accumulation region 9 made of the single crystal substrate 5, is exposed between the filament portions 6a, 7a. The distance between the linear portions 6a and 7a, that is, the pitch, is set to several μm to several 100 μm, which is smaller than the diameter of the electron beam.

FIG. 5 shows a scan converting storage tube incorporating the storage target 4 shown in FIGS. 3 and 4. In FIG. This storage tube includes an electron gun 11 within a vacuum enclosure 10,
It is constructed by sequentially arranging a deflection system 12, a collimation system 13, and a storage target 4. The electron gun 11 has cathodes 1 arranged in sequence.
4, control electrode 15, acceleration electrode 16, focusing electrode 1
7 and an asteig electrode 18, which produce an electron beam directed toward the target 4. The deflection system 12 consists of a vertical deflection system 19 consisting of a pair of vertical deflection plates arranged along the beam path, and a horizontal deflection system 20 consisting of a pair of horizontal deflection plates, and is arranged in two orthogonal directions, the vertical direction and the horizontal direction. Deflect the electron beam to The collimation system 13 is composed of a wall electrode 21 and a field mesh electrode 22, and functions as a collimation lens (convex lens) for making a low-energy electron beam perpendicularly enter the target 4 during reading or the like. First and second lead members 23 and 24 are connected to the storage target 4 as means for applying different voltages to the first and second collector electrodes 6 and 7, respectively. It has been derived.

The first lead member 23 is connected to the prime (erase) power supply 2 via a resistor 25 and a switch circuit 26.
7, selectively connected to the first power source 28 for writing and the power source 29 for reading. Second lead member 2
4 is the second
It is connected to the power supply 31 for writing, and connected to the first lead member 23 during prime and read,
The same potential as that of the first lead member 23 is applied.
Note that an output line is connected to the first lead member 23 via a capacitor 32.

To operate the storage tube of FIG.
-1kV to the cathode 14, cathode 14 to the control electrode 15
Voltage of about 0 to -75V, accelerating electrode 1
6 to 0V (+1kV with respect to cathode 14), focusing electrode 17 and asteig electrode 18 with a voltage optimally adjusted according to the amount of electron beam, and wall electrode 21 with 0V (+1kV with respect to cathode 14). ), 1.5 kV is applied to the field mesh electrode 22 (2.5 kV to the cathode 14).

Operation According to the present invention, when the target 4 having a plurality of collector electrodes 6, 7 is used, writing is possible even when the erase potential difference is zero. If destructive reading is performed, the prime mode and erase mode are essentially unnecessary. However, steps corresponding to the conventional prime mode may be provided to ensure a secure erased state. When obtaining a prime state (erase state) prior to writing an electrical signal to the target 4, first the switch circuit 2
6 contact a is turned on and switch circuit 30 contact d is turned on.
By turning on, the first and second collector electrodes 6, 7 are connected to the prime power source 27,
The potentials of the collector electrodes 6 and 7 are each set to, for example, 1350 V (2350 V with respect to the cathode), which is higher than the first cross potential, and the entire effective scanning area of the target 4 is bombarded with an unmodulated electron beam. As a result, all the storage surfaces 8 have the same voltage of 1350V as the collector electrodes 6 and 7 (2350V with respect to the cathode). That is, secondary electrons and electron-hole pairs are generated by electron beam impact, but
In this embodiment, since the potential of the collector electrodes 6 and 7 is set to the highest in the storage tube, the potential of the storage surface 8 increases based on the operation in which the emitted secondary electrons are captured at the highest potential part. is prevented, and the accumulation surface 8
The potential of the collector electrodes 6 and 7 becomes the same as that of the collector electrodes 6 and 7. Further, the electron-hole pairs also depend on the potential arrangement between the storage surface 8 and the collector electrodes 6, 7, and work so that the storage surface 8 has the same potential as the collector electrodes 6, 7. Therefore, substantially no erase potential difference V _E is generated between the collector electrodes 6, 7 and the storage surface 8.

According to the present invention, writing is possible even when the erase potential difference V _E is zero, so the writing state is immediately entered. During writing, the vertical deflection system 1 is operated with the beam amount set appropriately using the control electrode 15.
9 and/or horizontal deflection system 20 . Further, different voltages are supplied to the first collector electrode 6 and the second collector electrode 7 so that a potential difference in the range of several volts to several hundred volts is generated. That is, contact b of the switch circuit 26 is turned on, and a voltage higher than the voltage of the field mesh electrode 22, for example, 9 kV (10 kV with respect to the cathode) is applied from the first write power source 28 to the first collector electrode 6, and The contact e of the switch circuit 30 is turned on, and a voltage of, for example, 10.1 kV for the 9.1 kV cathode is applied to the second collector electrode 7 from the second write power source 32.

FIG. 6 is a schematic band diagram for explaining the writing operation. If the storage surface 8 and the collector electrodes 6 and 7 are at the same potential due to erasing as shown in FIG. 6A, then the writing By applying different voltages to the collector electrodes 6 and 7, the state shown in FIG. 6B is achieved, and a drift electric field corresponding to the collector potential difference V _W =100V is generated in the accumulation region between the electrodes 6 and 7. It is assumed that the potential of the collector electrode 7 is higher than that of the collector electrode 6.

As shown in FIG. 6B, when writing is performed by electron beam impact with a potential difference between the collectors and a voltage higher than the first cross potential, secondary electrons are emitted and electron-hole pairs are generated in the solid. . The emitted secondary electrons and the electrons in the solid are captured by the collector electrode 7, but the holes are captured by the surface levels near the accumulation surface 8 and increase the potential of the accumulation surface 8, as shown in FIG. A band state as shown in D is formed.

That is, when an electron beam is projected onto the storage surface 8,
An adjacent portion of the collector electrode 7 having a high potential has the same potential as the collector electrode 7, but an adjacent portion of the collector electrode 6 having a low potential does not have the same potential as the collector electrode 7. Therefore, a potential difference V _W is obtained between the collector electrode 6 and the storage surface 8 . As shown in FIG. 6D, the state in which holes are captured in the solid and the band is bent corresponds to the state in which the equivalent pixel capacitance consisting of the collector electrodes 6 and 7 and the storage surface 8 is charged. . The charging level, that is, the writing level, of the storage surface 8 by electron beam projection is approximately proportional to the potential difference V _W (drift electric field) between the collector electrodes 6 and 7, assuming that the beam amount is constant.
The higher the value, the deeper the writing level can be obtained. Furthermore, the writing speed can be increased by the drift electric field. Even when the above-mentioned potential difference (drift electric field) is extremely low, a certain effect can be obtained. However, experimentally, it is desirable to set the voltage to 3 to 4 volts or more due to the SN ratio (signal-to-noise ratio). The higher the potential difference is, the faster the writing level and writing speed will be, but since dielectric breakdown will occur, it cannot be made higher than the dielectric breakdown level (approximately 300 V in the case of saphire).

Next, when the contact d of the switch circuit 30 and the contact c of the switching circuit 26 are turned on and the same voltage is applied from the reading power supply 29 to the first and second collector electrodes 6 and 7, the writing portion is In this case, the band bends as shown in FIG. 6E, and the center of the storage surface 8 has a higher potential than the collector electrodes 6 and 7. On the other hand, the portion to which no writing has been performed remains in the state shown in FIG. 6A. As a result, a charge pattern corresponding to writing is generated on the target 4.

The voltage of the collector electrodes 6, 7 in the read mode is equal to or higher than the first crossing potential, and preferably the difference from the voltage of the collector electrodes 6, 7 in the write mode is several times higher than the first crossing potential.
This value is in the range of 100 volts. When the entire surface of the target 4 is scanned with an unmodulated electron beam while applying the same voltage to the collector electrodes 6 and 7, the 6th
In the write portion shown in FIG. E, a part of the electrons generated by the electron beam impact is used to neutralize the holes, so that the amount of electrons flowing into the collector electrodes 6 and 7 is reduced. On the other hand, in the non-written portion as shown in FIG. 6A, neutralization of holes does not occur, so that a large amount of electrons flows into the collector electrodes 6 and 7. Therefore, depending on the magnitude of the current obtained from the collector electrodes 6 and 7, it is possible to distinguish and detect the written portion and the non-written portion. When reading as described above is performed, in an ideal case, the potential of the storage surface 8 becomes the same as the potential of the collector electrodes 6 and 7 after reading, resulting in an erased state. This reading operation can also be considered as a discharge of the equivalent pixel capacitance of the storage surface 8. That is, when an electron beam is projected onto the writing area (charged area), discharge occurs, and the state shown in FIG. 6E changes to that shown in FIG. 6A.
returns to the state (erased state). At the time of this reading, the potentials of the collector electrodes 6 and 7 are set to the same value equal to or higher than the first crossing potential, as in the case of erasing or priming, so that after the electron beam impact, the state is the same as that of erasing or priming. Note that in order to discharge the holes trapped in the deep trap level, it is desirable to set the collector potential to at least 500V or more. Incidentally, when a field mesh electrode 22 is provided as shown in FIG. 5, it is necessary to set the potential of the collector electrodes 6 and 7 higher than the potential of the field mesh electrode 22. This is to prevent secondary electrons generated by impact from the reading beam from being captured by the field mesh electrode 22 and then captured by the collector electrodes 6 and 7.

As is clear from the above, this embodiment has the following advantages.

(a) During one cycle consisting of erasing, writing and reading, or one cycle consisting of writing and reading, the voltage value of the collector electrodes 6 and 7 is kept at a high value higher than the first crossing potential, so when switching modes The width of the voltage change becomes smaller, and the mode switching time can be shortened. Therefore, it is possible to read data immediately after writing, and it is possible to provide an oscilloscope or an A-D converter that performs writing and reading almost in real time.

(b) Even when the erase potential difference V _E is zero, writing can be performed due to the effect of the collector-collector potential difference V _W , so the operation of applying the erase potential difference V _E becomes unnecessary, and writing can be started quickly.

(c) Since the data enters the erased state after reading, it is also possible to omit the erase operation (prime operation).

(d) Since the voltage fluctuation width of the collector electrodes 6 and 7 is small, the configuration of the switching circuit becomes easy.

(e) Since the potential of the collector electrodes 6 and 7 during reading is set to be the highest in the storage tube, secondary electrons generated based on the reading beam are not captured by the field mesh electrode 22, etc., making it possible to read accurately. become.

Second Embodiment (FIG. 7) A scan conversion type storage tube according to a second embodiment of the present invention shown in FIG. 7 is obtained by omitting the field mesh electrode 22 from the storage tube shown in FIG. 5. Therefore,
Components common to those in FIG. 5 are given the same reference numerals and their explanations will be omitted. In this way, even when the field mesh electrode is not provided, writing and reading can be performed in exactly the same manner as in the first embodiment, and the following effects can also be obtained.

If the field mesh electrode is not provided, the electron beam will not be captured by the field mesh electrode, resulting in improved beam efficiency and faster writing speed.

Writing by secondary electrons from the field mesh electrode is eliminated, and the resolution is increased.

Note that during reading and erasing by the storage tube shown in FIG. must be set.

Third embodiment (Figs. 8 and 9) The target 4a shown in Figs.
Similar to the target 4 in the figure, first and second collector electrodes 6 and 7 are provided in a comb-like shape on a sapphire single crystal substrate 5, and a third collector electrode 34 is provided in a meandering manner between the two. It is something that Note that the width of the linear portions 6a, 7a, and 34a of each electrode is 0.5 μm ~
50 μm, and the pitch of these is said to be several μm to several 100 μm. In this way, the three collector electrodes 6, 7,
Even if 34 is provided, the respective linear portions 6a, 7a, 34a are arranged parallel to each other in the target effective area, forming a stripe shape as a whole, so that it can be used in the same manner as the target 4 shown in FIG.

That is, this target 4a, like the target 4 in FIG. 3, is used by being incorporated into a storage tube as shown in FIG. 5 or 6. When incorporating into the storage tube, the lead members 23, 24, 35 of the three collector electrodes 6, 7, 34 are led out independently from the vacuum enclosure, and voltages are independently applied to the collector electrodes 6, 7, 34. The configuration is such that this is possible. Although various write and read operation methods are possible using this target 4a, a typical operation method will be described below.

First, when erasing, apply the same voltage to the three collector electrodes 6, 7, and 34, and
This is done in the same manner as in the embodiment. That is, if the same voltage is applied to each of the collector electrodes 6, 7, and 34, they can be regarded as a single electrode, so that they can be erased in exactly the same manner as in FIG. 3.

Next, when writing, the same voltage (for example, 9 kV) is applied to the first and second collector electrodes 6 and 7, and the third collector electrode 34 is Also high voltage (e.g.
9.1 kV) is applied to create a beam shock in the same manner as in the first embodiment. This allows writing exactly the same as in the first embodiment. That is, writing can be performed in a state where there is a potential difference V _W between the electrodes, and the same effects as in the first embodiment can be obtained.

At the time of reading, the same voltage is applied to the first, second, and third collector electrodes 6, 7, and 34, and the reading is performed in the same manner as in the first embodiment.

Another method for writing onto the target 4a in FIG. 8 is to apply a different voltage to each electrode 6, 7, 34 and project a writing beam. In this case, for example, 9 kV is applied to the first collector electrode 6, the next highest voltage, for example 9.1 kV, is applied to the third collector electrode 34, and the highest voltage, for example 9.2 kV, is applied to the second collector electrode 7. . This makes it possible to apply a potential difference V _W of 100 V between each electrode, making writing exactly the same as in the first embodiment possible.

Modifications Although the embodiments of the present invention have been described above, the present invention is not limited thereto, and includes modifications as follows, for example.

(A) As shown in Figure 10, the third
The collector electrodes 34a may be arranged in a grid pattern. That is, first, the third collector electrode 34 is provided in a grid pattern on the sapphire single crystal substrate 5, and
Third collector electrode 34 outside the target effective area
An insulating layer 36 may be provided thereon, and then the first and second collector electrodes 6 and 7 may be provided in a comb-like shape. Even when formed in this manner, the linear portions 6a, 7a, 34a of each electrode are arranged parallel to each other in the target effective area, so that the same effect as that of the target 4a in FIG. 8 can be obtained.

(B) A back electrode may be provided on the back surface of the substrate 5 and an appropriate voltage may be applied.

(C) _Two layers of polycrystalline SiO are provided on silicon,
This SiO ₂ layer may be used as an insulator storage layer.

(D) Instead of the sapphire single crystal substrate 5, MgO,
An insulating single crystal substrate such as CaF ₂ or MgF ₂ may also be used.

(E) The substrate 5 may be made of an amorphous insulator such as glass.

(F) Electrodes 6, 7, and 34 are made of Cr, Al, Ni, Mo, and Au.
It may be formed of a single layer or a composite layer. Also,
A transparent electrode such as SnO ₂ may also be used.

(G) In each embodiment, the direction in which the linear portions 6a, 7a, and 34a extend coincides with the horizontal scanning direction of the beam, but they may be arranged so as to be orthogonal to each other.

(H) In the storage tube shown in Fig. 5, the collimation system 1 is composed of the wall electrode 21 and the field mesh electrode 22.
Although the collimation system 13 is provided, a configuration may be adopted in which the collimation system 13 is omitted.

(I) It is of course applicable not only to writing waveforms but also to writing digital signals.

(J) A structure in which an insulator accumulation layer is provided on an alumina substrate or the like may be used.

(K) The circuit for applying voltage to the first and second collector electrodes 6 and 7 may be configured as shown in FIG. 11. That is, the power supplies 28 and 31 are set to 100V, for example.
Different voltage sources with a potential difference of Different voltages may be supplied to the two collector electrodes 6 and 7.

[Brief explanation of drawings]

Fig. 1 is a plan view showing the principle of a conventional target, Fig. 2 is a sectional view taken along the line - -, of the target of Fig. 1, and Fig. 3 is a plan view showing the principle of the target of the first embodiment of the present invention. Figure 4 is a cross-sectional view taken along the line -- of the target shown in Figure 3, Figure 5 is a cross-sectional view showing the principle of a storage tube incorporating the target shown in Figure 3, and Figure 6 is a cross-sectional view of the target shown in Figure 3. FIG. 7 is a cross-sectional view showing the principle of the storage tube of the second embodiment, and FIG. 8 is a diagram showing the target of the embodiment of FIG. 3. 9 is a plan view showing the principle of the target in FIG. 8, FIG. 10 is a plan view showing the principle of a modified target, and FIG. 11 is a collector electrode voltage application circuit of the modified example. FIG. 4... Storage target, 5... Substrate, 6... First collector electrode, 7... Second collector electrode,
8...Accumulation surface, 9...Accumulation area.

Claims (1)

[Claims] 1. An electric signal is written by deflecting and projecting an electron beam onto a storage target having a structure in which a plurality of collector electrodes are electrically insulated and arranged in parallel to each other on a storage substrate made of an insulating material. , during subsequent reading, secondary electrons are emitted to at least two adjacent collector electrodes of the storage target where there is substantially no potential difference between the plurality of collector electrodes and the storage surface of the base. applying voltages higher than and different from a first crossing voltage at which the ratio becomes 1; keeping the different voltages applied, selectively bombarding the storage target with an electron beam to write an electrical signal; Applying substantially the same voltage higher than the first crossing potential to the plurality of collector electrodes, and scanning the storage target with an unmodulated electron beam while maintaining the same voltage application state to read the write signal. A method of operating a scan conversion storage tube, characterized in that: 2. The method of operating a scan conversion type storage tube according to claim 1, wherein the voltage applied to the plurality of collector electrodes during the reading is the highest voltage among the storage tubes.