Method of controlling transmission light amount and television camera apparatus using the method

A television camera apparatus having a first image pick-up element and a second image pick-up element for converting an incident light entered from an object, comprising:

• first and second image pick-up units, each of which has a plurality of photoelectric converting elements, for generating said picture signal;
• a detection unit for detecting first and second luminance level ranges each higher than a predetermined level within said picture signal at first and second predetermined time instants, respectively, and detecting a change component between said first and second luminance level ranges;
• a transmission light amount control unit for controlling light amounts of said incident light with respect to the respective photoelectric converting elements of said second image pick-up unit;
• a predicting unit for predicting, at a preselected time instant before a third predetermined time instant, a third luminance level range at said third predetermined time instance higher than the predetermined level from said picture signal based on said change component from said detection unit;
• and
• a control unit coupled with said transmission light amount control unit, for controlling a light amount of said light entered into the light receiving plane of the photoelectric converting elements of said second image pick-up unit at a preselected time instant before at said third predetermined time instant, based upon an output of said predicting unit.

A transmission light amount control method used for a television camera apparatus having an image pick-up element and for acquiring a picture signal in such a manner that imaging light which is entered from an object is received by light receiving planes of a large number of photoelectric converting elements arrayed on said image pick-up element, and the imaging light received in the respective photoelectric converting elements is converted into said picture signal, comprising:

• a step (a) in which a picture signal range having a higher signal level than a predetermined level within a picture signal imaged at a first predetermined time instant is detected as a first high luminance level range, and a picture signal range having a higher signal level than said predetermined level is detected as a second high luminance level range within a picture signal imaged at a second predetermined time instant;
• a step (b) in which a change-component between said first high luminance level range and said second high luminance level range is detected;
• a step (c) in which a third luminance level range at a third predetermined time instant, having a higher signal level than a predetermined level from said picture signal is predicted at a preselected time instant before said third predetermined time instant based on said change component;
• and
• a step (d) in which the amount of said imaging light is controlled at said third predetermined time instant in response to a predicted third luminance level range.

A computer readable storage medium recording thereon program codes capable of being executed by a computer wherein:

• said program codes perform:
• a step in which imaging light entered from an object is received by light receiving planes of a large number of photoelectric converting elements arrayed on an image pick-up element, and the imaging light received by the respective photoelectric converting elements is photoelectrically converted so as to acquire picture signals;
• a step in which a picture signal range having a higher signal level than a predetermined level within a picture signal imaged at a first predetermined time instant is detected as a first high luminance level range among said acquired picture signals, and also a picture signal range having a higher signal level than said predetermined level is detected as a second high luminance level range within a picture signal imaged at a second predetermined time instant;
• a step in which a change-component between said first high luminance level range and said second high luminance level range is acquired;
• a step in which a third luminance level range at a third predetermined time instant, having a higher signal level than a predetermined level from said picture signal is predicted at a preselected time instant before said third predetermined time instant based on said change component;
• and
• a step in which said transmission light amount is controlled at said third predetermined time instant in response to a predicted third luminance level range.

A television camera apparatus for photoelectrically converting incident light originated from a photographing object to acquire a picture signal, comprising:

• an image pick-up unit containing a plurality of photoelectric converting elements;
• a detection unit for detecting a range of a picture signal having a signal level higher than a predetermined level within said picture signals acquired from said image pick-up unit as a high luminance level range;
• and
• a transmission light amount control unit for controlling incident light amounts of said imaging light from the photographing object with respect to the respective photoelectric converting elements every each of said photoelectric converting elements;
• wherein:
• said transmission amount control unit comprises:
• a change-component detecting unit for detecting a change component between a first high luminance level range which is detected by said detection unit at a first predetermined time instant, and a second high luminance level range which is detected by said detection unit at a second predetermined time instant after said first predetermined time instant;
• and
• a control unit of controlling the light amount of the incident light entered into said photoelectric converting elements based upon said first predetermined time instant, said second predetermined time instant, and said detected change-component, wherein
• said transmission light amount control unit predicts a fourth predetermined time instant based upon said first predetermined time instant, said second predetermined time instant, and said detected change component, within such a high luminance level range higher than said predetermined level, in which a dimension of said range is larger than, or equal to a predetermined dimension;
• and controls the light amounts of said incident light at said fourth predetermined time instant.

A transmission light amount control method used for a television camera apparatus having an image pick-up element and for acquiring a picture signal in such a manner that imaging light which is entered from an object is received by light receiving planes of a large number of photoelectric converting elements arrayed on said image pick-up element, and the imaging light received in the respective photoelectric converting elements is photoelectrically converted so as to produce said picture signal, comprising:

• a step (a) in which a picture signal range having a higher signal level than a predetermined level within a picture signal imaged at a first predetermined time instant is detected as a first high luminance level range, and a picture signal range having a higher signal level than said predetermined level is detected as a second high luminance level range within a picture signal imaged at a second predetermined time instant;
• a step (b) in which a change-component between said first high luminance level range and said second high luminance level range is detected;
• and
• a step (c) in which the amount of said imaging light is controlled in response to said first predetermined time instant, said second predetermined time instant, and said change-component;
• said step (c) further predicts a fourth predetermined time instant after said second predetermined time instant based upon said first predetermined time instant, said second predetermined time instant, and said detected change-component, at which the range of the picture signal having the signal level higher than said predetermined level is imaged, and a dimension of said range is larger than, or equal to a predetermined dimension;
• and predicts said range of the picture signal having the signal level higher than said predetermined level at said predicted fourth predetermined time instant;
• and controls the transmission light amount of said transmission light amount varying unit at said third predetermined time instant in response to said predicted picture signal range.