초록 ▼

A focus indicating device in a camera employing a photoelectric transducer for scanning the image of an object to output a time series signal equivalent to the brightness distribution of the image. A contrast detection circuit extracts a power spectrum in a high spatial frequency range which becomes

A focus indicating device in a camera employing a photoelectric transducer for scanning the image of an object to output a time series signal equivalent to the brightness distribution of the image. A contrast detection circuit extracts a power spectrum in a high spatial frequency range which becomes a contrast signal of the image. An indication meter indicates the contrast signal directly in the view finder of the camera with the deflection angle indicating a maximum value when proper focus is obtained.

대표청구항 ▼

A focus determination device in a camera, comprising: photoelectric transducing means for scanning the image of an object and producing a time series signal equivalent to the brightness distribution of said image; a contrast detection circuit for extracting a power spectral signal and for producing

A focus determination device in a camera, comprising: photoelectric transducing means for scanning the image of an object and producing a time series signal equivalent to the brightness distribution of said image; a contrast detection circuit for extracting a power spectral signal and for producing a contrast signal of said image; and indication means for indicating said contrast signal directly in a view finder of said camera, said contrast detection circuit comprising means to convert said time series signal into an analog waveform, a differentiation circuit for time differentiating said analog waveform to provide a differentiation signal, and an absolute value circuit receiving said differentiation signal to cause the signal from said differentiation circuit to have one polarity, said indicating means being responsive to the output of said absolute value circuit.