Imaging apparatus having electron source array

• US 8,203,611 B2
• Filed: 05/20/2008
• Issued: 06/19/2012
• Est. Priority Date: 05/21/2007
• Status: Expired due to Fees

• Current Assignee: Futaba Corporation, Hamamatsu Photonics KK, Nippon Hoso Kyokai, Pioneer Corporation
• Original Assignee: Futaba Corporation, Hamamatsu Photonics KK, Nippon Hoso Kyokai, Pioneer Corporation
• Inventors: Honda, Yuki, Namba, Masakazu, Hirano, Yoshiyuki, Okazaki, Saburo, Egami, Norifumi, Watabe, Toshihisa, Takiguchi, Yoshiro, Kobayashi, Akira, Itoh, Shigeo, Taniguchi, Masateru, Nakamura, Kazuhito, Miya, Kenta, Okuda, Yoshiyuki, Sakemura, Kazuto
• Primary Examiner(s): BAROT, BHARAT
• Application Number:
  US12/123,707
• Publication Number:
  US 20080291307A1
• Time in Patent Office: 1,491 Days
• Field of Search: 348/162, 348/166, 348/302, 250/208.1, 250/214.1
• US Class Current: 348/162
• CPC Class Codes: H01J 31/26 Image pick-up tubes having an input of visible light and electric output tubes without defined electron beams and having a light ray scanning photo-emissive screen H01J40/20
• CPC Class Codes: H01J 31/40 having grid-like image screen through which the electron ray passes and by which the ray is influenced before striking the output electrode, i.e. having "triode action"
• CPC Class Codes: H04N 5/32 Transforming X-rays cameras or camera modules for generating image signals from X-rays H04N23/30; circuitry of SSIS for transforming X-rays into image signals H04N25/30

Abstract

An imaging apparatus includes an electron emission array having electron sources arranged in matrix form, a photoelectric conversion film opposed to the electron emission array, and a control and drive circuit configured to select one or more horizontal scan lines in a given video signal output period and to cause the electron sources included in the selected one or more horizontal scan lines to emit electrons toward the photoelectric conversion film, wherein the control and drive circuit is further configured to cause the electron sources included in the selected one or more horizontal scan lines to emit electrons toward the photoelectric conversion film in any one or more blanking periods excluding both a blanking period immediately following the given video signal output period and a blanking period immediately preceding a next video signal output period in which the one or more horizontal scan lines will be selected next time.

Claims

1. An imaging apparatus, comprising:

an electron emission array having electron sources arranged in matrix form and having a plurality of horizontal scan lines;

a photoelectric conversion film opposed to the electron emission array; and

a control and drive circuit configured to select one or more of the horizontal scan lines in a given video signal output period and to cause the electron sources included in the selected one or more horizontal scan lines to emit electrons toward the photoelectric conversion film to produce a video signal,

wherein the control and drive circuit is further configured to cause the electron sources included in the selected one or more horizontal scan lines to emit electrons toward the photoelectric conversion film in any one or more blanking periods excluding both a blanking period immediately following the given video signal output period and a blanking period immediately preceding a next video signal output period in which the one or more horizontal scan lines will be selected next time.

2. The imaging apparatus as claimed in claim 1, wherein said any one or more blanking periods include a plurality of blanking periods intervening between an end of the given video signal output period and a start of the next video signal output period.

3. The imaging apparatus as claimed in claim 2, wherein the plurality of blanking periods includes a given blanking period and a blanking period next following the given blanking period.

4. The imaging apparatus as claimed in claim 1, wherein a blanking period during which electrons are emitted from the electron sources included in the selected one or more horizontal scan lines selected in the given video signal output period differs from a blanking period during which electrons are emitted from the electron sources included in one or more horizontal scan lines selected in another video signal output period.

5. The imaging apparatus as claimed in claim 2, wherein at least one of the plurality of blanking periods during which electrons are emitted from the electron sources included in the selected one or more horizontal scan lines selected in the given video signal output period differs from any one or more blanking periods during which electrons are emitted from the electron sources included in one or more horizontal scan lines selected in another video signal output period.

6. The imaging apparatus as claimed in claim 1, wherein said any one or more blanking periods during which electrons are emitted from the electron sources included in one of the selected one or more horizontal scan lines differ from said any one or more blanking periods during which electrons are emitted from the electron sources included in another one of the selected one or more horizontal scan lines.

7. The imaging apparatus as claimed in claim 1, wherein the electron emission array includes a first electrode for emitting electrons and a second electrode for creating a potential gap with the first electrode, and a potential gap is created between the first electrode and the second electrode to draw out electrons from the first electrode.

8. The imaging apparatus as claimed in claim 7, wherein a potential gap created between the first electrode and the second electrode in said any one or more blanking periods is set larger than a potential gap created between the first electrode and the second electrode in the given video signal output period.

9. The imaging apparatus as claimed in claim 7, wherein at least one of the first electrode and the second electrode receives a voltage in said any one or more blanking periods, said voltage being identical to a voltage applied in the given video signal output period.

10. The imaging apparatus as claimed in claim 1, wherein the photoelectric conversion film is configured to generate electric charge therein in response to light arriving from an external source, and is configured to amplify the electric charge therein.

11. The imaging apparatus as claimed in claim 1, further comprising a signal level detecting unit configured to detect a signal level of the video signal output from the selected one or more horizontal scan lines in the given video signal output period, wherein a time length during which electrons are emitted from the electron sources included in the selected one or more horizontal scan lines toward the photoelectric conversion film in said any one or more blanking periods varies depending on the signal level of the video signal detected by the signal level detecting unit.

12. The imaging apparatus as claimed in claim 7, wherein further comprising a signal level detecting unit configured to detect a signal level of the video signal output from the selected one or more horizontal scan lines in the given video signal output period, wherein a potential gap created between the first electrode and the second electrode in the electron sources included in the selected one or more horizontal scan lines in said any one or more blanking periods varies depending on the signal level of the video signal detected by the signal level detecting unit.