In the present invention, a cathode assembly for an X-ray tube is provided including a cathode cup, a pair of emitters disposed within the cup and each configured to emit an electron beam therefrom and an electrode spaced from the pair of emitters and configured to affect the shape and/or intensity of the electron beams emitted by the pair of emitters. The electrode includes a rod extending across a central aperture defined within the electrode that enables the electrode to grid or focus the electron beam or beams emitted from the emitters using a bias voltage between +10 kV and −10 kV.

In the present invention, a cathode assembly for an X-ray tube is provided including a cathode cup, a pair of emitters disposed within the cup and each configured to emit an electron beam therefrom and an electrode spaced from the pair of emitters and configured to affect the shape and/or intensity of the electron beams emitted by the pair of emitters. The electrode includes a rod extending across a central aperture defined within the electrode that enables the electrode to grid or focus the electron beam or beams emitted from the emitters using a bias voltage between +10 kV and −10 kV.

The present invention addresses the problem of providing a device with which it is possible to adjust the focal point of an electron beam both toward a shorter focal point and toward a longer focal point after an electronic gun was fitted on a counterpart device. The aforementioned problem can be solved by an electron gun including a photocathode, and an anode, the electron gun furthermore comprising an intermediate electrode disposed between the photocathode and the anode, the intermediate electrode comprising an electron-beam passage hole through which an electron beam released from the photocathode passes, and the electron-beam passage hole having formed therein a drift space in which, when an electrical field is formed between the photocathode and the anode due to application of a voltage, the effect of the electrical field can be disregarded.

The present invention addresses the problem of providing a device with which it is possible to adjust the focal point of an electron beam both toward a shorter focal point and toward a longer focal point after an electronic gun was fitted on a counterpart device.

The aforementioned problem can be solved by an electron gun including a photocathode, and an anode, the electron gun furthermore comprising an intermediate electrode disposed between the photocathode and the anode, the intermediate electrode comprising an electron-beam passage hole through which an electron beam released from the photocathode passes, and the electron-beam passage hole having formed therein a drift space in which, when an electrical field is formed between the photocathode and the anode due to application of a voltage, the effect of the electrical field can be disregarded.

An electron gun includes a cathode including an electron emitting portion, an extraction electrode for extracting electrons emitted from the electron emitting portion, and a focusing electrode for focusing the electrons extracted by the extraction electrode. The focusing electrode includes an outside electrode having a tubular shape, and an inside electrode arranged inside the outside electrode. The inside electrode defines a first space having a columnar shape, and includes a first surface on a side of the cathode, and a second surface on an opposite side of the first surface. An inside surface of the outside electrode and the second surface of the inside electrode define a second space. The inside electrode includes an electron passage hole, and a communicating portion which makes the first space and the second space communicate with each other.

An electron gun includes a cathode including an electron emitting portion, an extraction electrode for extracting electrons emitted from the electron emitting portion, and a focusing electrode for focusing the electrons extracted by the extraction electrode. The focusing electrode includes an outside electrode having a tubular shape, and an inside electrode arranged inside the outside electrode. The inside electrode defines a first space having a columnar shape, and includes a first surface on a side of the cathode, and a second surface on an opposite side of the first surface. An inside surface of the outside electrode and the second surface of the inside electrode define a second space. The inside electrode includes an electron passage hole, and a communicating portion which makes the first space and the second space communicate with each other.

The invention relates to an electron gun for generating a flat electron beam, comprising a cathode with an emission surface which is curved about a central axis and which is designed to emit electrons. The electron gun further comprises an accelerating device for accelerating the electrons in a radial direction towards a target region on the central axis. Furthermore, the emission surface has a width in the azimuth direction and a height oriented perpendicularly to the width, said width being at least ten times greater than the height.

The invention relates to an electron gun for generating a flat electron beam, comprising a cathode with an emission surface which is curved about a central axis and which is designed to emit electrons. The electron gun further comprises an accelerating device for accelerating the electrons in a radial direction towards a target region on the central axis. Furthermore, the emission surface has a width in the azimuth direction and a height oriented perpendicularly to the width, said width being at least ten times greater than the height.

In the present invention, a cathode assembly for an X-ray tube is provided including a cathode cup, a pair of emitters disposed within the cup and each configured to emit an electron beam therefrom and an electrode spaced from the pair of emitters and configured to affect the shape and/or intensity of the electron beams emitted by the pair of emitters. The electrode includes a rod extending across a central aperture defined within the electrode that enables the electrode to grid or focus the electron beam or beams emitted from the emitters using a bias voltage between +10 kV and 10 kV.

In the present invention, a cathode assembly for an X-ray tube is provided including a cathode cup, a pair of emitters disposed within the cup and each configured to emit an electron beam therefrom and an electrode spaced from the pair of emitters and configured to affect the shape and/or intensity of the electron beams emitted by the pair of emitters. The electrode includes a rod extending across a central aperture defined within the electrode that enables the electrode to grid or focus the electron beam or beams emitted from the emitters using a bias voltage between +10 kV and 10 kV.