Hitachi, Ltd.

Hitachi Industry & Control Solutions, Ltd.

Tomoaki Nishiguchi

Hideharu Ono

Akira Ando

Toshiyuki Yokoyama

Iori Umezawa

Hideharu Oono

Masanori Miyoshi

Hiroyuki Miyahara

Makoto Asuka

Yukitoshi Shirota

Toshifumi Inokuchi

Li Yuan

Miya Morimoto

A change in a subject is quickly sensed and a focusing lens is driven with degradation in durability and out-of-focus states of output video images due to driving of the focusing lens more than necessary avoided. To achieve the object described above, the invention relates to an imaging apparatus that controls a focusing lens based on a contrast signal provided from a video signal and includes a controller that performs first evaluation based on comparison between the value of the contrast signal and the value of a main threshold, performs second evaluation after the first evaluation based on comparison between the value of the contrast signal and a sub-threshold that is greater or smaller than the main threshold and is set to decrease or increase with the lapse of time, and performs focus control on the focusing lens based on a result of the second evaluation.

Apparatus, imaging method, and focus control apparatus to control autofocus based on contrast signal

A focus control apparatus that achieves a focused state even when a subject is a point light source includes a contrast signal generator that divides a captured image screen into a plurality of areas, extracts a frequency component based on a video signal for each of the divided areas, and generates a first contrast signal based on the frequency component. A controller extracts a luminance intensity based on the video signal for each of the divided areas, determines, for each of the divided areas, a second contrast signal generated by increasing or decreasing the magnitude of the first contrast signal from the divided area based on the magnitude of the luminance intensity, determines a lens position evaluation value that is the sum of the second contrast signals, and performs the focus control based on the lens position evaluation value.

Focus control apparatus and method

A focus control apparatus reduces the degree of out-of-focus of an image of an intense point light source during zooming in contrast-based autofocus control. A zooming lens moves in an optical axis direction to perform magnification change and a focusing lens moves in the optical axis direction to perform focus adjustment and is driven in accordance with a trace curve corresponding to the distance to a subject. A controller evaluates, during the magnification change operation, based on the rate of change in the number of high-luminance pixels at which the number of high-luminance pixels in an output image from the imaging apparatus changes with the zoom magnification, whether or not the focusing lens is driven in accordance with a trace curve corresponding to the distance to the subject before the magnification change operation is performed or a trace curve corresponding to a distance to the subject of infinity.

Imaging apparatus, imaging method, and focus control apparatus

An imaging apparatus that performs focus control includes a signal conversion processing part that converts a subject image into a video signal, an image acquisition part that acquires the video signal output from the signal conversion processing part, a focusing area setting part that sets a focusing area as an evaluation value calculation area on an imaging screen acquired by the image acquisition part, an effective range selection part that obtains effective code density in an image of the focusing area with respect to each lens position while moving the lens and determines whether or not the lens position is in an effective range suitable for focusing based on the effective code density, and a focusing degree calculation part that obtains a focusing degree in the lens position when a determination that the lens position is located in the effective range is made in the effective range selection part.

Imaging apparatus, imaging method and imaging system

An imaging device performs optimum focus correction at low cost with an autofocus device that moves a lens for focusing an image. The imaging device includes a camera signal processing part having a contrast signal generation part that extracts a high frequency component from a video signal and generates a contrast signal of the video signal based on the extracted high frequency component. The imaging device also has a controller that performs focus control based on the contrast signal. The controller performs an ON/OFF control of an infrared rays cut filter and includes a recording part to hold a set value of an ON/OFF state of the infrared rays cut filter. The camera signal processing part includes a signal conversion processing part to change a ratio of RGB of the video signal to be sent to the contrast signal generation part based on the set value.

Imaging device with the autofocus

For improving picture quality in auto-focus control, image processing deviceadjusts output picture imaged by image pick-up elementand displayed by a display section, comprises storage sectionfor storing predetermined de-focus threshold value of variation amount of intensity value of output picture; first adder sectionfor calculating intensity value time difference variation amount between intensity value of output picture being input and intensity value of the predetermined-time previous output picture before the output picture is input; and variation amount comparison sectionfor comparing intensity value time difference variation amount and de-focus threshold value, wherein when variation amount comparison section determines that intensity value time difference variation amount is less than de-focus threshold value to be a comparison object, intensity value of output picture after being adjusted is calculated by subtracting intensity value time difference variation amount from intensity value of output picture being input.

Imaging sensing device, image sensing processing device, and image processing method

For preventing frequent use of auto-focus control and also for acquiring stable in-focus positions for target-objects, this invention comprises system control sectionhaving a second mode to drive magnification adjustment lensor focus adjustment lensupon a user command, and a third mode to transition to a first mode under pre-determined conditions in the second mode, and to set in-focus states of a lens group, wherein system control sectionstores a reference target-object distance in reference target-object distance storage sectionwhen focus adjustment lensis driven by user commands in the second mode, drives focus adjustment lensnot based on a current target-object distance but the lens in-focus trajectory data to retain the reference target-object distance when the magnification adjustment lensis driven by user commands, and re-transitions to the second mode without updating the reference target-object distance, after the third mode.

Image sensing device, image sensing device control method, and program for the control method

A focus control apparatus and method capable of shortening a focus adjustment time in focus control. The method includes extracting a first high frequency component depending upon a first cutoff frequency and a second high frequency component depending upon a second cutoff frequency higher than the first cutoff frequency from a video signal, generating first and second contrast signals of the video signal respectively based on the first and second high frequency components, using a quotient obtained by dividing a value of the first contrast signal by that of the second contrast signal as a parameter, exercising focus control based on the parameter, and setting the first and second cutoff frequencies so as to cause a value of the parameter to assume a peak when a focus lens in an image pickup apparatus is located in a position at a predetermined distance from an in-focus position.

Focus control apparatus useful for image pick up apparatuses equipped with an auto focus function and method therefor

In order to obtain stable lens positions to have an object imaged in focus when the temperature of lenses changes, an imaging device of the present invention comprises a system control sectionhaving a imaging mode and a correction mode, the imaging mode in which a group of lensesare controlled and moved to focusing positions for a predetermined distance at first and are further moved to correct the focusing positions for the predetermined distance to the object during imaging according to the temperature compensation data, the correction mode in which the group of lensesare controlled and moved to have the temperature compensation data corrected when the temperature change is larger than or equal to a predetermined temperature difference, a correction coefficient calculation sectionfor calculating the correction coefficient to correct the temperature compensation data based on first focusing positions of the group of lenses to which the group of lenses are moved according to the temperature compensation data before corrected and second focusing positions of the group of the lenses to which the group of the lenses are automatically moved from the first focusing positions to have the object the predetermined distance away imaged in focus based on the focus evaluation value under a condition under which a moving range of the group of lenses is restricted, when the system control section is on the correction mode, a temperature compensation data correction sectionfor correcting the temperature compensation data to be used for the imaging mode based on the correction coefficient calculated by the correction coefficient calculation section.

Imaging device

A zoom camera having enhanced focusing stability during high magnification zooming under environments of high temperatures or low temperatures. When the zoom camera performs zoom-in operations in an environment of high or low temperatures, aperture control is added as the zoom magnification becomes higher and the temperature becomes higher or lower whereby the depth of field is made deeper to assure the presence of a range with good focusability.

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Mito, Japan

Tomoaki Nishiguchi