MULTIPLE ELECTRON MIRROR APPARATUS AND METHOD

• US 3,789,370 A
• Filed: 07/18/1972
• Issued: 01/29/1974
• Est. Priority Date: 07/18/1972
• Status: Expired due to Term

• Current Assignee: Jaime A. Bari, Jerry A. Sievers, Kent N. Maffitt
• Original Assignee: Jaime A. Bari, Jerry A. Sievers, Kent N. Maffitt
• Inventors: Bari, Jaime A., Maffitt, Kent N., Sievers, Jerry A.
• Primary Examiner(s): Fears, Terrell W.
• Application Number:
  US05/272,779
• Time in Patent Office: 560 Days
• Field of Search: 250/311,307 340/173CR 178/6.6A
• US Class Current: 365/128
• CPC Class Codes: G11C 11/23 using electrostatic storage on a common layer, e.g. Forrester-Haeff tubes or William tubesG11C11/22 takes precedence
• CPC Class Codes: H01J 29/60 Mirrors
• CPC Class Codes: H01J 31/58 Tubes for storage of image or information pattern or for conversion of definition of television or like images, i.e. having electrical input and electrical output electrostatic memories using electron beam tubes G11C11/23

Abstract

An information storage and retrieval system with a large storage capacity and having a write and a read mode of operation is provided by using a plurality of electron mirrors. Preferably three electron mirrors are used of which one is a modulating electron mirror and the other two are storage electron mirrors with each storage mirror having a plurality of storage areas. The electron beam is directed by a magnetic prism and appropriate biasing of the electron mirrors. During the write mode, the electron beam is mirrored by the modulating mirror and a page (a plurality of bits) of input information presented as a pattern of charge at the modulating mirror modulates the beam. The mirrored electron beam is directed to an addressed storage area of a selected storage mirror where the entire page of information contained in the modulated beam is stored as a pattern of charge. The same page can also be stored at the second storage mirror to improve the reliability of the apparatus during the read mode. During the read mode the electron beam is mirrored without modulation except at a storage mirror to be read where it is directed to a storage area for modulation and is then presented to a readout array where all bits of information represented by the modulation are read simultaneously.

Claims

1. An electron beam information storage and retrieval apparatus with a read mode and write mode of operation comprising:

an electrically biased modulating electron mirror biased during the read mode to passively mirror an electron beam and biased during the write mode to modulate and mirror an electron beam presented to any pattern of charge on the mirror;

an electrically biased storage electron mirror biased during the read mode to modulate and mirror an electron beam presented to any pattern of charge stored on the storage mirror and biased during the write mode to cause an electron beam to impinge to store a pattern of charge thereon;

means for applying information to the surface of said modulating mirror as a pattern of charge, readout means;

means for providing an electron beam; and

means for sequentially presenting the electron beam to the modulating mirror, the storage mirror and the readout means during the read mode and to the modulating mirror and the storage mirror during the write mode.

2. An electron beam information storage and retrieval apparatus in accordance with claim 1 wherein said means for applying information to the surface of the modulating mirror includes a photodiode array and a plurality of light sources providing a light image in accordance with the information to be stored, said photodiode array positioned for responding to the light image received from said plurality of light sources to provide a pattern of charge at the surface of the modulating mirror.

3. An electron beam information storage and retrieval apparatus in accordance with claim 2 wherein said light sources are light emitting diodes.

4. An electron beam information storage and retrieval apparatus in accordance with claim 2 wherein said light sources are provided by a plasma display panel.

5. An electron beam information storage and retrieval apparatus in accordance with claim 1 wherein the pattern of charge at the surface of the modulating mirror represents a plurality of bits of information and the means presenting the electron beam to the modulating mirror includes an electron focusing lens for increasing the cross-section of the electron beam so the beam encompasses the pattern of charge.

6. An electron beam information storage and retrieval apparatus in accordance with claim 5 wherein the storage mirror has a plurality of storage areas and the means presenting the electron beam to the storage mirror includes an electron focusing lens for reducing the cross-section of the beam so the beam encompasses only a single one of the storage areas and deflection means for directing the electron beam to any one of the plurality of storage areas whereby random access to the storage areas is provided.

7. An electron beam information storage and retrieval apparatus in accordance with claim 6 wherein the deflection means includes two deflection units, each unit having a plurality of deflection plates.

8. An electron beam information storage and retrieval apparatus in accordance with claim 7 wherein each deflection unit has eight deflection plates.

9. An electron beam information storage and retrieval apparatus in accordance with claim 5 wherein the readout means includes a plurality of diodes, at least one diode for each bit of said plurality of bits of information.

10. An electron beam information storage and retrieval apparatus in accordance with claim 9 wherein the means for presenting the electron beam to the readout means includes an electron focusing lens for increasing the cross-section of the electron beam so the beam encompasses the plurality of diodes.

11. An electron beam information storage and retrieval apparatus in accordance with claim 6 wherein the means presenting the electron beam includes a multi-aperture immersion type objEctive lens positioned adjacent the storage electron mirror with an opening provided in the objective lens for each of the plurality of storage areas.

12. An electron beam information storage and retrieval apparatus in accordance with claim 11 wherein the objective lens includes three multi-apertured spaced plates, the apertures of which are coaxially aligned.

13. An electron beam information storage and retrieval apparatus in accordance with claim 12 wherein a plate similar to said three multi-apertured spaced plates is positioned between the deflection means and the three multi-apertured spaced plates to mechanically remove any electrons in a beam presented to it which may be outside the aperture to which the beam is directed.

14. An electron beam information storage and retrieval apparatus in accordance with claim 1 wherein the means presenting the beam includes a plurality of electron focusing lenses, each lens having a plurality of lens forming elements, each of the elements having an opening through which the electron beam passes with each element in one of the lenses physically and electrically connected to a corresponding element in each of the other lenses.

15. An electron beam information storage and retrieval apparatus in accordance with claim 14 wherein three concentric rings provide said lens forming elements for each of said plurality of focusing lenses.

16. An electron beam information storage and retrieval apparatus in accordance with claim 1 wherein the means sequentially presenting the electron beam includes a magnetic prism about which the means providing an electron beam, the modulating mirror, the storage mirror and read-out means are positioned.

17. An electron beam information storage and retrieval apparatus in accordance with claim 1 wherein the means sequentially presenting the beam includes a magnetic prism located centrally of the means providing an electron beam, the modulating mirror, the storage mirror and the readout array.

18. An electron beam information storage and retrieval apparatus with a read mode and write mode of operation comprising:

an electrically biased modulating electron mirror biased during the read mode to passively mirror an electron beam and biased during the write mode to modulate and mirror an electron beam presented by any pattern of charge stored on the mirror;

a plurality of electrically biased storage electron mirrors with any one storage mirror biased during the read mode to modulate and mirror an electron beam and any one storage mirror biased during the write mode to cause an electron beam to impinge and store a pattern of charge thereon, the remaining storage mirrors during the read and write mode biased to passively mirror an electron beam;

means for applying information to the surface of said modulating mirror as a pattern of charge, a readout means;

means providing an electron beam; and

means for sequentially presenting the electron beam to the modulating mirror, the storage mirrors and the readout means during a read mode and to the modulating mirror and at least one of the storage mirrors during the write mode.

19. A method for storing information bits on an electron mirror comprising the steps of forming a pattern of charge on a first electron mirror representative of a plurality of bits of information;

electrically biasing the first electron mirror so an electron beam presented to it is mirrored and modulated by the pattern of charge on the first electron mirror;

presenting an electron beam to the first electron mirror to encompass the pattern of charge on the first electron mirror;

electrically biasing a second electron mirror to permit an electron beam presented to it to impinge thereon; and

presenting the electron beam after it is mirrored and modulated by the electron mirror to the second electron mirror for impingement thereon to store a pattern of charge representative of the modulated electron beam.

20. A method as set foRth in claim 19 wherein said step of presenting the electron beam to the second electron mirror includes the steps of reducing the cross-section of the electron beam and directing the electron beam to one of a plurality of storage areas on the second electron beam.

21. A method for storing information bits on a plurality of electron mirrors comprising the steps of forming a pattern of charge on a first electron mirror representative of a plurality of bits of information;

electrically biasing the first electron mirror so an electron beam presented to it is mirrored and modulated by the pattern of charge on the first electron mirror;

presenting an electron beam to the first electron mirror to encompass the pattern of charge on the first electron mirror;

electrically biasing all but one of the remaining ones of the plurality of electron mirrors to mirror an electron beam presented to it;

electrically biasing said one electron mirror to permit an electron beam presented to it to impinge thereon; and

sequentially presenting an electron beam to the first electron mirror for modulation of the electron beam by the pattern of charge at the first electron mirror and then to said remaining electron mirrors until said one electron mirror is reached where the modulated electron beam impinges on said one electron mirror to store a pattern of charge representative of the modulated electron beam.

22. A method as set forth in claim 21 wherein the step of sequentially presenting an electron beam to said one electron mirror includes the steps of reducing the cross-section of the beam prior to impingement of the beam on said one electron mirror and presenting the electron beam to one of a plurality of storage areas on said one electron mirror for impingement thereon.

23. A method for storing information bits on an electron mirror and retrieving the stored information there-from comprising the steps of forming a pattern of charge on a first electron mirror representative of a plurality of bits of information;

electrically biasing the first electron mirror so an electron beam presented to it is mirrored and modulated by said pattern of charge;

presenting an electron beam to the first electron mirror to encompass said pattern of charge;

electrically biasing a second electron mirror to permit an electron beam presented to it to impinge thereon;

presenting the electron beam after it is mirrored and modulated by the electron mirror to the second electron mirror for impingement thereon to store a pattern of charge representative of the modulated electron beam;

electrically biasing the first electron mirror so an electron beam presented to it is passively mirrored;

electrically biasing the second electron mirror so an electron beam presented to it is mirrored and modulated by the pattern of charge stored thereon;

presenting the electron beam to the first electron mirror and upon being passively mirrored thereby;

presenting the electron beam to the second electron mirror for mirroring and modulation by the pattern of charge stored thereon; and

presenting the electron beam upon being mirrored by the second electron mirror to a readout array for detection of the modulations contained in the beam which are representative of the information bits stored.

24. A method as set forth in claim 23 wherein each of said steps presenting the electron beam to the second electron mirror includes the steps of reducing the cross-section of the electron beam and directing the electron beam to one of a plurality of storage areas on the second electron beam.

25. A method for storing information bits on a plurality of electron mirrors and retrieving the stored information therefrom;

comprising the steps of forming a pattern of charge on a first electron mirror representative of a plurality of bits of information;

electrically biasing the first electron mirror so an electron beam presented to it is mirrored and modulated by saiD pattern of charge;

electrically biasing all but one of the remaining ones of the plurality of electron mirrors to mirror an electron beam presented to it;

electrically biasing said one electron mirror to permit an electron beam presented to it to impinge thereon;

presenting an electron beam to the first electron mirror to encompass said pattern of charge;

sequentially presenting the electron beam to the first electron mirror for modulation of the electron beam by the pattern of charge at the first electron mirror and then to said remaining electron mirrors until said one electron mirror is reached where the modulated electron beam impinges on said one electron mirror to store a pattern of charge representative of the modulated electron beam;

electrically biasing the first electron mirror so an electron beam presented to it is passively mirrored;

electrically biasing said one electron mirror so an electron beam presented to it is mirrored and modulated by the pattern of charge stored thereon;

sequentially presenting the electron beam to the first electron mirror, then to said remaining electron mirrors including said one electron mirror where the electron beam is mirrored and modulation by the pattern of charge stored thereon; and

presenting the electron beam upon being mirrored by the last of said remaining electron mirrors to a readout array for detection of the modulation contained in the electron beam which are representative of the information bits stored.

26. A method as set forth in claim 25 wherein each of said steps of sequentially presenting an electron beam to said one electron mirror includes the steps of reducing the cross-section of the beam prior to impingement of the beam on said one electron mirror and presenting the electron beam to one of a plurality of storage areas on said one electron mirror for impingement thereon.