The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
May. 27, 2008

Filed:

Dec. 14, 2004
Applicants:

Tsutomu Ichikawa, Sakai, JP;

Makoto Akesaka, Sakai, JP;

Inventors:

Tsutomu Ichikawa, Sakai, JP;

Makoto Akesaka, Sakai, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04N 5/222 (2006.01); G03B 15/03 (2006.01);
U.S. Cl.
CPC ...
Abstract

A photocurrent corresponding to the intensity of the light from the subject which photocurrent is successively generated at predetermined intervals is converted into a voltage by being logarithmically compressed by a logarithmic compression circuit in a divisional cell of a metering sensor during the preliminary light emission of the flash immediately before the actual shooting. Then, the voltage level is outputted to a controller as an analog metering signal. The controller A/D converts the successively inputted analog metering signal to generate digital data corresponding to the BV value representative of the brightness of the subject under flash light, and stores the digital data into a RAM. Then, the controller calculates a subject distance for determining the light emission amount of the flash in the actual shooting by performing a digital calculation including an integration calculation of the BV values obtained under ambient light and under flash light.


Find Patent Forward Citations

Loading…