US 4,377,742 A · Image sharpness detecting system · patentgrep

Loading patent…

Abstract

Disclosed is an image sharpness detecting system in which an image formed by an image forming optical system is received by an array of a plurality of optical-electronic transducer elements, and an illumination difference in each individual minute compartment of the above-described image is detected on the basis of the concurrently obtained output signal from a corresponding one of the optical-electronic transducer elements, while all the illumination differences are summed up over the entire area of a sensing region of the above-described image, whereby is obtained a signal representing the degree of sharpness of the image on the above-described array of optical-electronic transducer elements. In this system, the signal representative of the illumination difference in each individual minute compartment of the above-described image is at least non-linearly transformed by utilizing the non-linear characteristics for output versus input of a semiconductor element such as a transistor, and the signal representative of the degree of sharpness of the above-described image is obtained on the basis of the non-linearly transformed signal.

Claims86

Dependent claims

A system for detecting the sharpness of an image formed by an image forming optical means, comprising:

(A) image sensing means for sensing the image formed by said optical means, said image sensing means having an array of a plurality of radiation sensitive elements, the individual elements producing electrical signals corresponding to the radiations incident thereon, and said image sensing means having as its output to provide the electrical signals of the respective elements in a time-seriated manner;
(B) illuminance difference detecting means for providing electrical signals representing illuminance difference in the individual minute compartments of said image based on the output of said image sensing means;
(C) signal transforming means for non-linear transformation and absolute-value transformation of the electrical signals provided by said illuminance difference detecting means, said signal transforming means having at least one semi-conductor element embodying signal non-linear transformation characteristics, whereby said electrical signals are at least non-linearly transformed by utilizing said semi-conductor;
and
(D) image sharpness output means for providing an output representing the sharpness of said image on said image sensing means based on the non-linearly transformed and absolute-value transformed electrical signals by said signal transforming means.

2 more elements

A system for detecting the sharpness of an image formed by an image forming optical means, comprising:

(A) image-sensing means for sensing the image formed by said optical means, said image-sensing means having an array of a plurality of radiation sensitive elements, the individual elements producing electrical signals corresponding to the radiations incident thereon, and said image-sensing means having as its output to provide the electrical signals of the respective elements in a time-seriated manner;
(B) illuminance difference detecting means for providing electrical signals representing illuminance differences in the individual minute compartments of said image based on the output of said image-sensing means;
(C) signal transforming means for non-linear transformation and absolute-value transformation of the electrical signals provided by said illuminance difference detecting means;
(D) transformation control means for controlling the signal transforming operation of said signal transforming means, said transformation control means controlling the signal non-linear transforming operation of said signal transforming means so as to differ non-linear transformation of those of the signals provided by said illuminance difference detecting means which correspond to a predetermined detection region previously set to said image with respect to the different positions of the individual minute image compartments within said predetermined detection region;
and
(E) image sharpness output means for providing an output representing the sharpness of said image on said image-sensing means based on the non-linearly transformed and absolute-value transformed electrical signals by said signal transforming means.

3 more elements

A system for detecting the sharpness of an image formed by an image forming optical means, comprising:

(A) image sensing-means for sensing the image formed by said optical means, said image-sensing means having an array of a plurality of radiation sensitive elements, the individual elements producing electrical signals corresponding to the radiations incident thereon, and said image-sensing means having as its output to provide the electrical signals of the respective elements in a time-seriated manner;
(B) differentiating circuit means for providing electrical signals representing illuminance difference in the individual minute compartments of said image based on the output of said image-sensing means;
(C) differentiating operation control means for controlling the signal differentiating operation of said differentiation circuit means, said differentiating operation conrol means rendering operative said differentiation circuit means in only a time when those of the outputs from said image-sensing means which correspond to a predetermined detection region previously set to said image are applied to said differentiation circuit means and rendering substantially inoperative said differentiation circuit means except in that time.
(D) signal transforming means for non-linear transformation and absolute-value transformation of the electrical signals provided by said differentiation circuit means;
and
(E) image sharpness output means for providing an output representing the sharpness of said image on said image-sensing means based on the non-linearly transformed and absolute-value transformed electrical signals by said signal transforming means.

3 more elements

A system for detecting the sharpness of an image formed by an image forming optical means, comprising:

(A) image sensing-means for sensing the image formed by said optical means, said image-sensing means having an array of a plurality of radiation sensitive elements, the individual elements producing electrical signals corresponding to the radiation incident thereon, and said image-sensing means having as its output to provide the electrical signals of the respective elements in a time-seriated manner;
(B) differentiating circuit means for providing electrical signals representing illuminance difference in the individual minute compartments of said image based on the output of said image-sensing means, said differentiation circuit means having its differentiation constant arbitrarily adjustable;
(C) differentiation constant adjusting means for adjusting the differentiation constant of said differentiation circuit means in accordance with the aperture ratio of said image forming optical means;
(D) signal transforming means for non-linear transformation and absolute-value transformation of the electrical signals provided by said differentiation circuit means;
and
(E) image sharpness output means for providing an output representing the sharpness of said image on said image-sensing means based on the non-linearly transformed and absolute-value transformed electrical signals by said signal transforming means.

3 more elements

A system for detecting the sharpness of an image formed by an image forming optical means, comprising:

(A) image sensing means for sensing the image formed by said optical means, said image-sensing means having an array of a plurality of radiation sensitive elements, the individual elements producing electrical signals corresponding to the radiation incident thereon, and said image-sensing means having as its output to provide the electrical signals of the respective elements in a time-seriated manner;
(B) illuminance difference detecting means for providing electrical signal representing illuminance difference in the individual minute compartments of said image based on the output of said image-sensing means;
(C) signal transforming means for non-linear transformation and absolute-value transformation of the electrical signals provided by said illuminance difference detecting means;
and
(D) image sharpness output means for providing an output representing the sharpness of said image on said image-sensing means based on the non-linearly transformed and absolute-value transformed electrical signals by said signal transforming means, said image sharpness output means comprising
signal integrating means for integrating those of the electrical signals non-linearly transformed and absolute-value transformed by said signal transforming means which correspond to a predetermined detection region previously set to said image;
and
integration control means for causing the integration signal of said signal integrating means to damp at a rate having a predetermined characteristic whereby said image sharpness output means provides said output representing the sharpness of said image on said image-sensing means on the basis of the time measured from the start of damping of the integration signal of said signal integrating means and necessary for said integration signal to attain a predetermined level.

5 more elements

A system for scanning an image formed by an image forming optical means, comprising:

(A) image scanning means for scanning the image formed by said optical means, said image scanning means having an array of a plurality of radiation sensitive elements, the individual elements producing electrical signals corresponding to the radiations incident thereon, and said image scanning means having as its output to provide the electrical signals of the respective elements in a time-seriated manner;
and
(B) image signal level adjusting means for adjusting the level of the image signal obtained by the output of said image scanning means, said image signal level adjusting means receptive of the output of said image scanning means for adding its electrical signals for every arbitrary number of consecutive elements in said array of the plurality of radiation sensitive elements in said image scanning means to produce output signals, whereby said added signals are produced as said image signal to adjust the level of said image signal given on the basis of the output of said image scanning means.

Dependencies are inferred from the claim text.