Canon Kabushiki Kaisha

Tamayo Hiroki

Ichiro Nomura

Takao Ogura

Kazuyuki Ueda

Yoshihiro Yanagisawa

Miki Tamura

Hidetoshi Nojiri

Hisanobu Azuma

Shigeki Matsutani

Toshihiko Takeda

Jun Iba

Hirotomo Taniguchi

Takanori Suwa

Provided is an X-ray generator including an electron passage in an electron-passage forming member; and a target on an insulative substrate. The transmission X-ray generator irradiates the target with electrons that have passed through the electron passage to generate X-rays. The target is provided at a central region of the substrate; the electron passage accommodates a secondary-X-ray generating section that generates X-rays by irradiation with electrons reflected from the target; the secondary-X-ray generating section and the target are disposed so that both of X-rays generated by direct irradiation of the target with the electrons and X-rays generated by irradiation of the secondary-X-ray generating section with the electrons reflected from the target are radiated to the outside; and at least part of the peripheral region of the substrate has higher transmittance for the X-rays generated at the secondary-X-ray generating section than the central region of the substrate.

X-ray generator and X-ray imaging apparatus

In an X-ray generation apparatus of transmission type including an electron emission source, and a target generating an X-ray with collision of electrons emitted from the electron emission source against the target, the X-ray generation apparatus further includes a secondary X-ray generation portion generating an X-ray with collision of electrons reflected by the target against the secondary X-ray generation portion, and the secondary X-ray generation portion and the target are arranged such that the X-ray generated with the direct collision of the electrons against the target and the X-ray generated with the collision of the electrons reflected by the target against the secondary X-ray generation portion are both radiated to an outside. X-ray generation efficiency is increased by effectively utilizing the electrons reflected by the target.

X-ray generation apparatus and X-ray radiographic apparatus

An electron beam apparatus is provided having an electron emitting device which has a simple configuration, exhibits high electron emission efficiency, operates stably, and in which emitted electrons are effectively converged. The electron beam apparatus includes: an insulator having a notch on its surface; a gate positioned on the surface of the insulator; at least one cathode having a protruding portion protruding from an edge of the notch toward the gate, and positioned on the surface of the insulator so that the protruding portion is opposed to the gate; and an anode arranged to be opposed to the protruding portion via the gate, wherein the gate is formed on the surface of the insulator so that at least a part of a region opposed to the cathode is projected outward and recessed portions are provided in which ends of the gate are recessed and interpose the projected region.

Electron emitting device and image displaying apparatus using the same

A convex portionhaving a specific sectional shape is formed on a substratebetween electrodesand, and a gapis formed on a conductive film, connecting the electrodesand, on the convex portion, whereby the distance from the center of the gapserving as a electron-emitting portion to the stagnation point is reduced so as to enhance an electron emission efficiency.

Electron-emitting device and image display apparatus using the same

An image forming apparatus in which a first substrate provided with an electron-emitting device and an image displaying member which electrons emitted from the electron-emitting device irradiate are arranged to be opposed is provided with a deflecting means deflecting the electrons emitted from the electron-emitting device and a trapping unit trapping an inert gas ionized by the electrons. Thereby, the damages of the electron-emitting device by the inert gas are prevented, and the life of an image display apparatus is aimed to be elongated.

Image forming apparatus with reduced loss of electron source caused by the inert gas

A method for manufacturing an electron source includes the steps of covering a substrate provided with a first electrode and a second electrode by a container, introducing a gas composed of a carbon compound into the container, and forming a carbon film by applying a voltage between the first electrode and the second electrode. The relationship 1/(4/C &minus;1/C )&gE;S &gE;4S &minus;C is satisfied, where C is the conductance from the gas inlet to the position of the substrate nearest to the gas inlet, C is the conductance from the position of the substrate nearest to the gas inlet to the position of the substrate nearest to the gas outlet, S is the effective exhaust rate, S is the consumption rate of the gas, and C is the conductance from the substrate to the gas outlet. An apparatus for manufacturing an electron source and a method for manufacturing an image-forming apparatus are also disclosed.

Apparatus for manufacturing electron source, method for manufacturing electron source, and method for manufacturing image-forming apparatus

An electron-emitting device is provided with stable electron emission characteristics and with uniformity of electron emission. The present invention thus provides a method for producing an electron-emitting device having a pair of device electrodes opposed to each other and a thin film including an electron-emitting region, formed on a substrate, wherein a voltage is applied so that a potential of a front surface of the substrate becomes higher than a potential of the back surface thereof. On that occasion, the strength of the electric field is not more than 20 kV/cm between the front surface and the back surface of the substrate. The substrate is heated during the application of the voltage.

Methods for producing electron-emitting device, electron source, and image-forming apparatus

A semiconductor laser of the present invention includes a semiconductor laser structure having a waveguide extending along a resonance direction, an active layer provided at least partly in the waveguide, and a control unit for controlling the excited state of the semiconductor laser structure to change the relationship between wavelengths or propagation constants and threshold gains for transverse electric (TE) mode and transverse magnetic (TM) mode of the laser structure. The waveguide is designed such that threshold gains for the TE mode and the TM mode can be alternately made minimum under the control of the control unit.

Semiconductor laser, modulation method therefor and optical

A semiconductor laser includes a distributed feedback semiconductor laser structure having a plurality of regions. The regions are electrically separated from each other. A phase shift section is provided in a grating in one of the regions. In the semiconductor laser, .alpha. parameters for transverse electric (TE) and transverse magnetic (TM) polarization modes, in the vicinity of threshold currents for the TE mode and the TM mode, are made different from each other. An .alpha. parameter is defined by 4.pi./.lambda..multidot.(dn/dN)/(dg/dN) where .lambda. is a Bragg wavelength, n is an effective refractive index, N is an injection carrier density and g is a gain for each of the TE mode and the TM mode.

Semiconductor laser modulation method therefor and optical communication

A light absorbing layer is formed in a photodetector that receives and detects light guided therein. Carriers are generated in the light absorbing layer in response to the guided light. Unwanted carriers likely to be generated in regions other than the light absorbing layer when light is guided into the photodetector are swept out by a carrier sweeping arrangement to improve the time response and light-current characteristics of the photodetector.

Photodetector capable of sweeping out unwanted carriers and an optical

A field effect type photo-detector comprises a semiconductor buffer layer arranged on a substrate. A semiconductor activation layer is arranged on that buffer layer, and a source electrode, a drain electrode and a gate electrode are arranged on the activation layer. A depletion layer for controlling a current flow between the source electrode and the drain electrode is created in the activation layer by applying a voltage to the gate electrode. When light irradiates the activation layer, the depletion layer changes. The buffer layer has a wider band gap than that of the activation layer and has an energy gap which serves as a barrier to carriers. The buffer layer has a sufficiently wide band gap to prevent the absorption of light having an equal wavelength to that of the light irradiated to the activation layer.

Growing community of inventors

Zama, Japan

Tamayo Hiroki