JP2005114858A - Range-finding camera device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic range-finding camera device disusing an infrared ray or ultrasonic wave receiving/transmitting device and capable of instantaneously outputting information on a distance to a subject without using the fine vibration mechanism of a focus lens group. <P>SOLUTION: The camera device is equipped with a high-band component extraction part to extract the high-band frequency component of a video signal obtained from an optionally set focusing detection area within the image plane of one frame photoelectrically converted in imaging devices attached so that two of them exist at a front focus position and a rear focus position when one of them exists at the focal position of an imaging lens equipped with a focus driving means and an output means for outputting the information on the distance to the subject, and a level difference processing part to calculate a level difference between the high-band frequency components obtained from the focusing detection areas of the two imaging devices and repeatedly perform the increase/decrease of the driving voltage of the focus driving means until the level difference becomes zero or a preset threshold based on the level difference on the emitting surface of a spectral optical system to branch an optical image picked up by the imaging lens to three directions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an automatic distance measuring device used for a robot or the like, and more particularly to a distance measuring camera device in which a distance to a subject is determined by a single camera device.

  Conventionally, automatic distance measuring devices used for robots and the like include triangulation type, ultrasonic or infrared type, etc., as well as simple, home-use small TV cameras currently on the market A method of obtaining the distance to the subject from the focal length of the focused lens using an autofocus (hereinafter referred to as AF) function which is mainly used for the above is also conceivable.

  In the triangulation method, the optical axes of the two lenses are overlapped so that two images obtained through the two lenses of the reference field lens and the reference field lens arranged at a constant interval (base line length) overlap each other. The distance to the subject from the angle between the optical axis of the reference field lens and the optical axis of the reference field lens when the direction changes and the optical axis of the reference field lens overlaps the base line (the line connecting the center points of the two lenses) Is what you want.

  In addition, the method using ultrasonic waves or infrared rays, the ultrasonic wave or infrared ray emitted from the ultrasonic wave or infrared transmitter toward the subject is reflected by the subject and returned by the receiver, and is emitted from the transmitter. Then, the distance to the subject is obtained by measuring the time until it returns to the receiver.

  The method using the AF function is to extract a high frequency component from a video signal obtained by photoelectric conversion with an image pickup device such as a CCD of a TV camera, and so that the high frequency component is maximized. The focus is adjusted by a so-called “mountain climbing servo system” which drives the focus lens group, and the distance from the focal length to the subject is obtained. This method utilizes the phenomenon that when the imaging lens is focused on the subject, the high frequency component of the optical image formed on the imaging surface is maximized and the contrast is also maximized accordingly. Therefore, it is also called “contrast method”.

FIG. 6 shows a block diagram of a conventional example of the distance measuring method of “mountain climbing servo method”.
As shown in FIG. 6, in the distance measuring method of this example, the motor of the driving device 110 is driven via the driving device controller 109 to move the focus lens group 102 of the imaging lens 101 back and forth along the optical axis. Focusing is done by doing.

  The optical image picked up by the image pickup lens 101 is formed on the photoelectric surface of the image pickup device 103, photoelectrically converted, and output as a video signal. This video signal is subjected to processing such as double correlation sampling / gamma correction in the camera circuit 104 and is output to the output terminal 105 as a standard television signal, and is added to the high-pass filter 106 so that only the high frequency component is present. After being extracted and detected by the detector 107, it is output as a focus control voltage (hereinafter referred to as focus voltage) corresponding to the high frequency component of the video signal. Since the focal voltage corresponds to the definition of the optical image captured by the imaging lens 101, the focal voltage is maximized when the imaging lens is focused on the subject, and the focal voltage decreases as the focal point deviates before and after the subject. A tendency as shown in FIG. That is, when the position of the focus lens group 102 is at the position where the imaging lens is focused on the subject, that is, at the point P in FIG. 7, the focus voltage becomes maximum, and decreases as the position of the focus lens group 102 deviates from the point P. It will be.

  The differential hold circuit 108 in FIG. 6 samples and holds the focus voltage output from the detector 107 shown in FIG. 6 at regular intervals, as shown in the curve of the differential hold circuit output voltage in FIG. Is a circuit that generates a positive voltage if the focus voltage is decreasing with time, and a negative voltage if the focus voltage is decreasing with time. The drive controller 109 outputs the output voltage of the difference hold circuit 108. Is positive, the motor of the driving device 110 is rotated forward, for example, to move the position of the focus lens group 102 forward, and if the output voltage is negative, the driving device 110 is rotated reversely, for example, to rotate the focus lens group 102. It is a device that controls to move the position backward.

  In the distance measuring device using the “mountain climbing servo method” AF function described above, when the distance between the distance measuring device and the subject changes due to the movement of the subject or the position of the distance measuring device, the focus lens group The drive device 110 is controlled by the drive device controller 109 so that the lens 102 vibrates finely back and forth, and the high frequency components of the video signal when the focus lens group 102 is positioned at the front and rear ends of the vibration are detected. The detector 107 detects the signal and outputs it as a focus voltage. The difference hold circuit 108 samples and holds the focus voltage when the front end and the rear end are reached, and the difference in level of the focus voltage between the front and rear ends becomes zero. The position of the focus lens group 102 is moved in the forward direction or the reverse direction by outputting a positive or negative output voltage. The position where the level difference of the focus voltage becomes zero is the focus position P (see FIG. 7).

  When the focus lens group 102 changes the position of the focus of the image pickup lens from the closest distance to the infinite (∞) direction, that is, when the focus voltage starts a hill-climbing operation, the focus lens group 102 follows. The trajectory climbs the mountain as it is, and once reaches the in-focus position P (see FIG. 7) and then passes the in-focus position P, the output voltage of the difference hold circuit 108 is inverted and the focus lens group 102 is moved in the reverse direction. It moves again, passes through the focal point P again, and moves in the opposite direction again. The focus lens group 102 is stopped at the in-focus position P by repeating this operation several times.

  As described above, the output voltage of the difference hold circuit 108 is shown for the case where the focus lens group 102 is moved from the close distance direction to the infinity (∞) direction, but the focus lens group 102 is moved from the infinity direction to the close distance direction. It is easily understood that the same applies to the case of moving. This is an example of an AF method for a television camera using a hill-climbing servo method.

  According to this hill-climbing servo system, an AF system that does not require infrared or ultrasonic wave receiving / transmitting devices or special optical members can be used, and focus detection is performed based on the sharpness of the subject image. It has the advantage of being able to focus almost accurately regardless of the distance or distance.

  However, in the AF method mainly using the focus lens group that is currently used, that is, in the AF method in which the focus lens group disposed near the subject is moved and focused, the focus is adjusted. When the focus lens group is vibrated by the driving mechanism, the focal length of the lens itself slightly changes together with the focal length of the lens.

  In other words, the hill-climbing servo system is a system that stops while vibrating at the top of the mountain (focusing point) by feeding back the increase or decrease of the focus voltage, so the focus lens group moves back and forth around the top of the mountain even during focusing. Therefore, the focal length of the imaging lens changes slightly for the above-mentioned reason. The vibration of the focal length of the lens means the change in the magnification of the picked-up image due to the change in the angle of image pickup of the lens, that is, the angle of view. Therefore, an image picked up by the hill-climbing servo AF method is always The size has also changed slightly.

  This subtle change in the size of the image is caused by a slight focus change in the case of imaging when the depth of field of the lens is shallow, such as when the aperture value is small and the zoom magnification is high (on the telephoto side). The voltage changes greatly, that is, the vibration amplitude of the focus lens group is small and often coincides with the in-focus point, but the lens aperture value is large and the zoom magnification is low (wide angle side). When the depth of field is deep, the focus voltage changes little, so the vibration amplitude of the focus lens group also increases, and the size of the captured image changes by several percent or more with the position vibration of the focus lens group. Since the depth of field is deep, the focus lens group recognizes an appropriate place as a focusing point, so it is difficult to obtain an image of a certain size.

  In addition to driving the lens focus with a hill-climbing servo system that finely vibrates the focus lens group as described above, the image pickup device is slightly vibrated with a piezo device, etc., one of the two wedge-shaped prisms is fixed, and the other Several methods have been proposed to drive the focus lens group of the lens by moving the glass to slightly vibrate the glass thickness in the optical axis direction. The time until is not instantaneous. Even though it vibrates at a higher speed, it may not operate correctly for a subject whose state changes at a high speed, such as a moving object or flicker, in order to compare different screens in time. On the other hand, when it is used as an image at the same time as ranging, it can be used for consumer VGA, NTSC, PAL broadcasting systems, etc., but HDTV (High Definition Television) where high image quality is required, and high-speed focusing time. It cannot be used for FA (factory automation) applications that require an accurate in-focus position and an image of a certain size.

Broadcast technology 2003 VOL. 56NO. 4 (Kenrokukan Publishing Co., Ltd.) Development of HD zoom lens "Precision Focus System" Masao Wada

  In view of the current situation described above, there is no need for an infrared / ultrasonic wave receiving / transmitting device or special optical member, and a mechanical mechanism that causes the focus lens group to vibrate (wobbling) like the hill climbing servo system described above. Provided is an automatic distance measuring camera apparatus that can instantaneously and accurately output distance value information and use a high-quality image without using a vibration mechanism.

As a result of intensive studies in view of the above, the present inventor has solved this problem by the following means. (1) An imaging lens including a focus driving unit that drives a focus lens group and a distance information output unit to a subject, a spectral optical system that branches an optical image captured by the imaging lens in at least three directions, and the spectral optics An imaging device mounted on each of the three optical image emitting surfaces of the system, and when one of them is at the focal position of the imaging lens, the other two are mounted so as to be in the front focus position and the rear focus position, respectively. A total of three imaging devices, three sets of camera circuits that form subject signals photoelectrically converted by the imaging devices into video signals, and arbitrary setting within one frame screen by the video signals output from the camera circuits A high-frequency component extracting unit that extracts a high-frequency component of the subject image obtained from the focused detection area, and the front focus position and the rear focus extracted by the high-frequency component extracting unit. And calculating a level difference between focus control voltages obtained by detecting high-frequency components of the video signals obtained from the focus detection areas of the two imaging devices mounted so as to be in a position, and based on the level difference A level difference processing unit that repeatedly increases and decreases the driving voltage for driving the focus driving means until the level difference becomes zero or less than a preset threshold value,
The distance information output means to the subject always outputs the distance information to the subject, and at the same time indicates that the level difference processing unit has focused when the level difference becomes zero or less than a preset threshold value. A ranging camera device characterized by outputting a focusing signal.

(2) The level difference processing unit calculates a level difference of a focus control voltage obtained by detecting a high frequency component of each video signal obtained from the focus detection area, and the focus driving unit is based on the level difference. (1), wherein the increase / decrease in the drive voltage for driving is repeatedly calculated until the level difference is zero or less than a preset threshold value and reaches a minimum value obtained within a preset time. The described ranging camera device.
(3) The ranging camera device according to (1) or (2) above, wherein the focus detection area is set near the center of the one-frame screen.

(4) In the ranging camera device, a plurality of motion detection areas having the same area as the focus detection area are set so as to surround the focus detection area in one frame screen, and the focus detection area And a motion vector detection means for calculating a level difference between the image data of the previous field and the current field of the pixel located at the center of each of the plurality of motion detection areas and detecting a motion vector of the imaging subject in the focus detection area. And a gate area control means for moving the focus detection area and the plurality of motion detection areas in accordance with a motion vector of the subject to be imaged detected by the motion vector detection means. The ranging camera apparatus according to any one of 1) to (3).

(5) The gate region control means generates a contour signal indicating the contour of the focus detection region, and the contour signal superimposing circuit provided at the output terminal of any one of the three sets of camera circuits. In the above item (4), the current position of the focus detection area can be displayed by superimposing a contour signal on the output video signal of the camera circuit and outputting the signal. Distance camera device.

(6) In the distance measuring camera apparatus, an imaging device moving unit that enables the two imaging devices mounted so as to be in the front focus position and the rear focus position to move back and forth along the optical axis, and the imaging lens An aperture drive means for driving the aperture mechanism, and aperture value information output means for outputting aperture value information of the aperture mechanism,
The aperture mechanism is driven manually or automatically via the aperture drive means, and the aperture value obtained from the aperture value information output means is between the maximum open value and an aperture value arbitrarily set near the aperture value, and The imaging device moving means is activated when the maximum aperture value is between the maximum aperture value and an aperture value arbitrarily set near the maximum aperture value, and the positions of the two imaging devices are controlled and moved. 6. The distance measuring camera device according to any one of (1) to (5), wherein:

(7) In the distance measuring camera device, the imaging lens includes a zoom mechanism, a zoom driving unit that drives the zoom mechanism, and a zoom value information output unit that outputs focal length value information of the zoom mechanism,
The zoom mechanism is driven via the zoom driving means, and the zoom value of the zoom mechanism obtained from the zoom value information output means is between the wide angle end and a zoom value arbitrarily set near the wide angle end, and telephoto The imaging device moving means is activated when the zoom lens is located between an end and a zoom value arbitrarily set in the vicinity thereof, and the positions of the two imaging devices are controlled and moved. The ranging camera device according to any one of (1) to (6) above.

(8) The imaging device moving unit is in a state of being operated by either the aperture value information of the aperture mechanism obtained from the aperture value information output unit or the zoom value information obtained from the zoom value information output unit. When the remaining information becomes a value for driving the imaging device moving means, the imaging device moving means operates corresponding to two pieces of information to control the positions of the two imaging devices. 8. The ranging camera device according to any one of (1) to (7), wherein the ranging camera device is moved.

(9) In the distance measuring camera apparatus, an imaging device moving unit that further allows two imaging devices mounted so as to be in the front focus position and the rear focus position to move back and forth along the optical axis; Calculate and detect depth-of-field information based on aperture value information obtained from the aperture value information output means, zoom value information obtained from the zoom value information output means, and distance information to the subject obtained from the distance information output means A depth-of-field detecting means for
The depth-of-field detection means calculates the depth-of-field information calculated from the aperture value information, the zoom value information, and the distance information to the subject. When the imaging device moving means is present between an arbitrarily set depth of field value and between the shallowest value and an arbitrarily set depth of field nearby, 6. The distance measuring camera device according to any one of (1) to (5), wherein the distance measuring camera device operates and controls / moves positions of the two imaging devices.

(10) In the distance measuring camera device, in place of the focus driving unit, an imaging device moving unit that allows an imaging device mounted so as to be a focal position of the imaging lens to move back and forth along the optical axis And distance information output means for outputting distance information to the subject based on the moving distance of the imaging device that moves back and forth by the imaging device moving means (1) to (9), The ranging camera device according to any one of the above.

(11) The ranging camera apparatus according to any one of (1) to (10), wherein the imaging devices are all monochrome imaging devices.

(12) The ranging camera device according to any one of (1) to (10), wherein the imaging devices are all color imaging devices.

(13) One of the imaging devices mounted so as to be a focal position of the imaging lens is a color imaging device, and two mounted so as to be the front focus position and the rear focus position are monochrome imaging. The range-finding camera device according to any one of (1) to (10), wherein the distance-measuring camera device is a device.

(14) The ranging camera apparatus according to any one of (1) to (13), wherein the imaging device is an area sensor.

(15) The ranging camera device according to any one of (1) to (13), wherein the imaging device is a linear sensor.

According to the present invention, the following effects are exhibited.
1. According to the invention of claim 1 of the present invention,
Distance information output system to subject by instantaneous high-speed calculation processing with a total of three imaging devices mounted so that one is at the focal position of the imaging lens and the other two are at the front focus position and the rear focus position, respectively. Since there is no mechanism for micro-vibration (wobbling) while mechanically moving the focus lens group or imaging device at all times, unlike the conventional hill-climbing servo system, the reciprocating motion until the focus lens group reaches the just focus is achieved. Therefore, it is possible to provide a distance measuring camera device suitable for a high-definition image system such as an HDTV without causing blurring and flicker due to a wobbling because of an accurate in-focus position at a high speed.

  Further, the level difference of the focus control voltage obtained by detecting the high frequency component of each video signal obtained from the focus detection area is calculated, and the drive voltage for driving the focus driving means is increased or decreased based on the level difference. Since the level difference processing unit is repeatedly executed until the level difference is zero or less than a preset threshold value, even if a noise signal is included in the high frequency component, it does not malfunction. In addition, it is possible to accurately detect the focus position, and output a focus signal indicating that the focus is achieved and distance information to the subject.

2. According to the invention of claim 2 of the present invention,
In addition to the effect of item 1, the level difference processing unit calculates a level difference of a focus control voltage obtained by detecting a high frequency component of each video signal obtained from the focus detection area, and based on the level difference The drive voltage for driving the focus drive means is repeatedly calculated until the level difference is zero or less than a preset threshold value and reaches a minimum value obtained within a preset time, and a preset threshold value is obtained. Even if the value is close to the noise level, the level difference value when the preset time is reached is determined as the in-focus position, so even if a noise signal is included in the high frequency component, malfunction occurs. In this way, it is possible to quickly and accurately achieve the in-focus position, and to output the in-focus signal and the distance information to the subject.

3. According to the invention of claim 3 of the present invention,
Since the focus detection area is set in the vicinity of the center of the one-frame screen, for example, if the distance measuring camera device of the present application is mounted as a robot eye, the robot is caused to follow so that the subject is always located at the center of the screen. The distance to the subject can be measured, and the distance to the subject can be output from the distance information output means as a distance information output signal.

4). According to the invention of claim 4 of the present invention,
In addition to the effects described above, a motion vector detection unit that detects a motion vector of the imaging target subject image, and the focus detection region and the plurality of focus detection regions according to the motion vector of the imaging target subject image detected by the motion vector detection unit And a gate area control means for moving the movement detection area, it is possible to accurately measure the distance while automatically following even if the subject moves.

5). According to the invention of claim 5 of the present invention,
The gate region control means generates a contour signal indicating the contour of the focus detection region, and inputs the contour signal to a contour signal superimposing circuit provided at one output terminal of the three sets of camera circuits; Since the contour signal can be superimposed and output on the output video signal of the camera circuit, the subject image for distance measurement can always be grasped on the screen.

6). According to the invention of claim 6 of the present invention,
Even in the state of a deep depth of field near the maximum aperture value or near the minimum aperture value of the imaging lens or a shallow depth of field, the imaging device moving means is driven based on the aperture value to connect the two imaging devices. The image position can be controlled and moved, and the slope of the peak due to the focus voltage approaches the slope suitable for measurement, facilitating instantaneous high-speed focusing calculation processing by the level difference processing unit, and as a result, the distance to the subject can be quickly It is possible to measure accurately and output as a distance information output signal from the distance information output means to the subject.

7). According to the invention of claim 7 of the present invention,
Even when the zoom value is a deep depth of field near the wide-angle end or near the telephoto end or a shallow depth of field, the imaging device moving means is driven based on the zoom value to form an image of the two imaging devices. The position can be controlled and moved, and the slope of the mountain due to the focal voltage approaches the slope suitable for measurement, so the instantaneous high-speed focusing calculation processing by the level difference processing unit is facilitated, and as a result, the distance to the subject can be quickly It is possible to measure accurately and output as a distance information output signal from the distance information output means to the subject.

8). According to the invention of claim 8 of the present invention,
The imaging device moving unit is in a state of being operated by either the aperture value information of the aperture mechanism obtained from the aperture value information output unit or the zoom value information obtained from the zoom value information output unit, When the remaining information becomes a value for driving the imaging device moving means, the imaging device moving means operates corresponding to two pieces of information, and the positions of the two imaging devices can be controlled / moved. Since the peak slope due to the focus voltage further approaches a slope suitable for measurement, the instantaneous high-speed focus calculation processing by the level difference processing unit is facilitated, resulting in extremely deep depth of field or extremely shallow depth of field. Even in the state of depth of field, the distance to the subject can be measured quickly and accurately, and can be output as a distance information output signal from the distance information output means to the subject.

9. According to the invention of claim 9 of the present invention,
Depth of field information calculated by adding not only the aperture value information output signal and the zoom position information output signal but also the distance information output signal to the subject, and the deepest value of the depth of field information and the vicinity thereof The imaging device moving means when it exists between the shallowest value and an arbitrarily set depth of field near the shallowest value. Since the imaging position of the two imaging devices can be controlled and moved by driving, the slope of the mountain due to the focus voltage can respond to changes in the depth of field due to the distance to the subject, and is also suitable for measurement As a result, the level difference processing unit facilitates instantaneous high-speed focusing calculation processing.As a result, the distance to the subject can be reduced even in an extremely deep depth of field or extremely shallow depth of field. Quick and Measured probability, from the distance information output means can output the distance information output signal to the subject.

10. According to the invention of claim 10 of the present invention,
Further, the imaging device moving means for enabling the imaging device mounted so as to be the focal position of the imaging lens to move back and forth along the optical axis, and the moving distance of the imaging device moved back and forth by the imaging device moving means Distance information output means for outputting distance information to the subject based on, when the imaging lens is a large lens, instead of a method of driving and focusing a large focus lens group to obtain distance information, By moving three imaging devices that are lightweight and easy to move, the AF signal and the focusing function are simultaneously performed at extremely high speeds, and the in-focus position is accurately detected and the focus signal and the subject indicating the in-focus state are detected. Distance information can be output.

11. According to the invention of claim 11 of the present invention,
When all the imaging devices are composed of monochrome imaging devices, an imaging device with an extremely high number of pixels can be used. Therefore, even in the case of a high-definition image method, a mechanical vibration mechanism is used for the AF method. Because there is no instantaneous high-speed calculation processing, distance information to the subject can be output instantaneously, and it is possible to control the just focus position with high-quality images, providing an automatic ranging camera device that outputs accurate position information it can.

12 According to the invention of claim 12 of the present invention,
If the imaging devices are all color imaging devices, a single-chip color imaging device with a high pixel count can be used, which can support high-definition image systems such as color HDTV broadcast systems, and can be used with AF mechanisms. Since no vibration mechanism is used, the distance information to the subject can be output instantaneously, and the image can be controlled to the just focus position with high-quality images. it can.

13. According to the invention of claim 13 of the present invention,
The imaging device is composed of a single pixel color imaging device with a high pixel number mounted at the just focus position, and a monochrome imaging device with a very high pixel number mounted at the front focus position and the rear focus position. Can be used for high-definition image systems such as color HDTV broadcast systems, and since no mechanical vibration mechanism is used in the AF mechanism, distance information to the subject can be output instantaneously and high-quality images can be output. Therefore, it is possible to provide a color type automatic ranging camera device that outputs accurate position information.

14 According to the invention of claim 14 of the present invention,
If an area sensor is used in the imaging device, it can easily cope with NTSC, PAL broadcasting systems, and HDTV and high-definition image systems that require high image quality by capturing and scanning the subject on the surface. It is possible to construct a system that is small in size including equipment and low in cost. Furthermore, as an application example, for FA (factory automation) applications that require high-speed focusing time, it can be provided as an optimum device that performs instantaneous high-speed focusing calculation processing without blurring and flicker due to wobbling.

15. According to the invention of claim 15 of the present invention,
If a linear sensor is used for the imaging device, sub-scanning means and a memory that are orthogonal to the scanning direction of the imaging device are required, but an image with a high number of pixels can be obtained in both the horizontal and vertical scanning directions. It is possible to provide an automatic ranging camera device that performs high-speed focusing calculation processing based on data and outputs extremely accurate distance information.

Embodiments of the present invention will be described in detail with reference to the drawings.
1 is a block diagram of a distance measuring camera device according to a first embodiment of the present invention, FIG. 2 is an explanatory diagram of an autofocus system according to the first embodiment, FIG. 3 is a block diagram of a distance measuring camera device according to the second embodiment, and FIG. FIG. 5 is an explanatory diagram of the rear and front depths of field of the second embodiment, and FIG. 5 is a block diagram of the distance measuring camera device of the third embodiment.
In the figure, 1 is a focus driving means, 2 and 22 are distance information output means, 3 is an imaging lens, 4 is a lens aperture mechanism, 5 is a zoom mechanism, 6 is a focus lens group, 7 is an aperture drive means, and 8 is an aperture value. Information output means, 9 is a zoom drive means, 10 is a zoom value information output means, 11 is a 3P prism, 12 is an imaging device moving means, 13 is a high-frequency component extraction section, 14 is a level difference processing section, and 5 is a motion vector detection Means, 16 is a gate area control means, 17 is a contour signal superimposing circuit, 18 is a main line output, 19 is a monitor output, 20 and 23 are output terminals, and 21: depth of field detection means.

  In this embodiment, as shown in FIG. 1, focus driving means 1 for driving the focus lens group 6, distance information output means 2 for the subject, aperture driving means 7, aperture value information output means 8, and zoom driving means. 9 and a zoom value information output means 10, and a 3P prism 11 composed of three prisms which are spectroscopic optical systems for branching an optical image captured by the imaging lens 3 in at least three directions; The imaging devices respectively mounted on the three optical image exit surfaces of the 3P prism 11, and when one of them is at the focal position of the imaging lens, the other two are at the front focus position and the rear focus position, respectively. A total of three image pickup devices A, B, and C mounted so as to become A / D (Analog / Digital) that forms subject signals photoelectrically converted by the image pickup devices A, B, and C into video signals ) Three sets of camera circuits including a conversion circuit, and a high pass for extracting a high frequency component of a subject image obtained from an arbitrarily set focus detection area in one frame screen by a video signal output from the camera circuit A high-frequency component extracting unit 13 comprising a filter HPF (hereinafter referred to as HPF), a gate (GATE) circuit for setting the focus detection region, and a detector for detecting the high-frequency component, and the high-frequency component Focus obtained by detecting high frequency components of each subject image obtained from the focus detection areas of the two imaging devices B and C mounted so as to be in the front focus position and the rear focus position extracted by the extraction unit 13 The level difference of the control voltage (hereinafter referred to as the focus voltage) is calculated, and the drive voltage for driving the focus driving means 1 is increased or decreased based on the level difference. , And a level difference processing unit 14 repeatedly executes until below a predetermined threshold value.

  The imaging lens 3 that captures an image of the subject always outputs information from ∞ to close range according to the movement of the focus driving unit 1 that drives the focus lens group 6 and the focus lens group 6, and at the same time, the level difference processing unit 14 outputs the level. Distance information output means 2 for outputting an in-focus signal (for example, a pulse signal) indicating that the lens is in focus when the difference becomes zero or less than a preset threshold value, and an aperture drive means for driving the lens aperture mechanism 4 7 and aperture value information output means 8 for outputting the aperture value information of the lens aperture mechanism 4, zoom drive means 9 for driving the zoom mechanism 5, and focal length position information from the telephoto end to the wide angle end of the zoom mechanism 5 are output. The zoom lens includes a zoom value information output unit 10. Here, each information output unit described above uses a voltage value (analog or digital signal) from a position detection sensor (for example, a potentiometer or an optical rotary encoder) as each information output.

  The optical image of the subject imaged by the imaging lens 3 passes through each of its exit surfaces via a spectroscopic optical system 3P prism 11 composed of three prisms generally used for broadcasting and industrial television cameras. Spectroscopic and image formation is performed on the three solid-state imaging devices A, B, and C that are mounted.

When the imaging device A mounted on the optical image exit surface of the 3P prism 11 is at the focal position of the imaging lens, the other two imaging devices B are in the front focus position, and the imaging device C is in the rear focus position. It is installed. The two imaging devices B and C drive an imaging device moving unit 12 that can move back and forth along the respective optical axes by output signals from an aperture value information output unit 8 and a zoom value information output unit 10 described later. Moving the imaging position.

  Video signals that have been photoelectrically converted by each solid-state imaging device and converted from analog signals to digital signals by A / D conversion circuits are subjected to image processing such as gamma correction, blanking processing, and addition of synchronization signals by camera circuits. It is output.

  1 and 2, only the high frequency component of the video signal output from the camera circuit is extracted by the HPF, and the high frequency component in the in-focus detection region set near the center of the screen by the gate circuit is detected by the detector. And a focus voltage obtained by detecting a high frequency component of the video signal is output from the detector. Since the focal voltage corresponds to the definition of the optical image captured by the imaging lens 3, the focal voltage value appearing in the detector output and the optical path length D to the subject of the imaging lens 3 are the focus lens of the imaging lens 3. In a state where the group 6 is in a position where the subject image is focused on the image pickup device A, the focus voltage of the image pickup device A is the maximum value Va, and the corresponding optical path length D is the A position and is mounted at the front focus position. The focus voltage of the image pickup device B is Vb, the corresponding optical path length D is the B position, the focus voltage of the image pickup device C mounted at the rear focus position is Vc, and the corresponding optical path length D is the C position.

  The level difference processing unit 14 in FIG. 1 samples and holds the focus voltage of the detector output at regular time intervals, and if the focus voltage is in an increasing direction with respect to time, a positive voltage is displayed. On the other hand, if it is a decreasing direction, it is a circuit that generates a negative voltage. The focus drive voltage output from the level difference processing unit 14 is converted from a digital signal to an analog signal by the D / A conversion circuit, and is sent to the focus drive means 1. Entered. If the focus drive voltage of the level difference processing unit 14 is positive, the focus drive means 1 moves the position of the focus lens group 6 forward (or backward), for example, by rotating the drive motor forward, and the focus drive voltage is If it is negative, for example, the drive motor is reversed to move the position of the focus lens group 6 backward (or forward).

In other words, the level difference of the focus voltage obtained by detecting the high frequency component extracted from the video signal by the imaging devices B and C attached to the front focus position and the rear focus position output from the high frequency component extraction unit 13 is calculated. Then, the focus position is determined by repeatedly executing the process of increasing or decreasing the focus drive voltage for controlling the focus drive unit 1 based on the level difference until the level difference becomes zero or less than a preset threshold value. .
Here, the high frequency component generally includes a noise signal, and it may be difficult to calculate until the level difference becomes zero due to a randomly generated noise signal. . In that case, when a predetermined threshold value slightly higher than the noise level is reached or when the level difference is equal to or lower than the threshold value set slightly higher than the noise level and within a preset time It is preferable to determine the in-focus position when the minimum value is reached.

  In FIG. 2, the AF method of the present invention compares the focus voltage Vb of the imaging device B at the front focus position and the focus voltage Vc of the imaging device C at the rear focus position, which are mounted on the exit surface of the 3P prism 11, The focus lens group 6 is controlled so that the focus voltage of the imaging device A is maximized, and a focus signal indicating that the focus is obtained from the distance information output means 2 (FIG. 1) to the subject at that time, and the subject. A distance information output signal is output from the output terminal 20 to the outside of the camera, and is used, for example, as a distance information signal between the distance measuring camera device of the present invention attached to the eyes of a robot and the subject.

Whether the focal voltage is maximum is determined by whether the focal voltage Va of the imaging device A is maximized by moving close to the optical path length D indicated by the horizontal axis in FIG. The voltage (Va, Vb, Vc) can be determined instantaneously by comparing with the level difference processing unit 14 (FIG. 1).
That is,
Focusing ... Va> Vb = Vc
When out of focus: Vb <Vc or Vb> Vc
Thus, Va> Vb = Vc is controlled while determining the moving direction of the focus lens group 6 based on the direction of the inequality sign. Thus, since the focus voltage is compared with a method in which the focus lens group 6 and the like are slightly vibrated (wobbling) as in the conventional example, the focus lens group 6 reaches the in-focus position without passing through the in-focus position. And can be stopped.

  In the above description, the focus detection area for extracting the high frequency component is the area near the center of the screen, but in order to track and measure a moving subject, if the area to be extracted is widened, the focus on the object to be imaged is increased. The detection range of the focus state is expanded, the detection accuracy cannot be ensured, and it becomes extremely difficult to obtain an appropriate focus state. For this reason, it is necessary to limit the arbitrary area to an extremely small area and to move in accordance with the movement of the subject.

  Therefore, as a motion vector detection method, the motion vector detection means 15 is provided so as to surround the focus detection area in the video signal output from the imaging device A via the camera circuit and the focus detection area. A screen (referred to as a block) is divided into nine areas with eight regions, and each representative point pixel in the previous field located at the center of each block and a field of image data of each representative point pixel in the block of the current field A known technique such as a block matching method that detects a motion vector of a subject image to be imaged in the focus detection area by calculating a level difference between them may be used.

  The area gate signal indicating the size of the focus detection area in the video signal divided by the motion vector detection means 15 is used to set the focus detection area according to the movement of the subject image in the focus detection area. The focus detection area gate signal input to the gate area control means 16 to be controlled and moved, and formed by the gate area control means 16 is applied to each of the gate circuits, and among the high frequency components output from each HPF. A focus obtained by detecting a high frequency component only in the focus detection area is input to the level difference processing unit 14.

  The gate region control means 16 generates a contour signal indicating the contour of the focus detection region, and inputs the contour signal to a contour signal superimposing circuit 17 provided at one output terminal of the three sets of camera circuits. Then, by superimposing a contour signal on the output video signal of the monitor output 19, the focus detection area is contour-displayed by the focus detection area gate signal. The movement of the subject image to be imaged in the focus detection area can be monitored.

The lens ideally forms a subject on a plane perpendicular to the optical axis on the image plane, but in reality, even if the subject is deep, the lens will focus when the depth of field is deep. A certain range before and after the combined position appears to be in focus. Depth of field includes
a) The deeper the aperture, the deeper the aperture.
b) The depth becomes deeper as the focal length of the zoom lens becomes shorter (wide-angle end).
c) The depth increases as the subject distance increases.
d) The depth behind is deeper than the depth ahead. It has the nature of

  Here, as described above, in the hill-climbing servo method (or contrast method) AF method, for example, when the lens has a small depth of field such as a small aperture value and a high zoom magnification (on the telephoto side), Since the slope of the mountain due to the focus voltage is steep, the level difference of the focus voltage obtained by detecting the high frequency component output from the high frequency component extraction unit 13 is calculated, and the focus driving means 1 is calculated based on the level difference. When the level difference reaches zero or below a threshold that is set slightly higher than the noise level, or the level difference is set slightly higher than the noise level in advance. The calculation of the level difference processing unit 14 that is repeatedly executed until reaching a minimum value that is not more than the threshold value and is obtained within a preset time period is that the noise signal is included in the high frequency component. It also, is easily and accurately performed.

  However, when the depth of field is deep, such as when the lens aperture value is large and the zoom magnification is low (on the wide-angle side), the slope of the mountain due to the focus voltage becomes very gentle. Therefore, the level difference calculation of the level difference processing unit 14 is unstable and is likely to be inaccurate. For this reason, the focus lens group 6 is likely to be stopped at an appropriate focusing point.

  Therefore, when the depth of field is deep, or in order to cope with a so-called blurry state in which the depth of field is shallow and an extreme blur image is generated, Imaging device moving means 12 for moving the imaging devices B and C back and forth along the optical axis, aperture driving means 7 for driving the aperture mechanism of the imaging lens 3, and aperture value information output for outputting aperture value information Means 8, zoom drive means 9 for driving the zoom mechanism 5 of the imaging lens 3, and zoom value information output means 10 for outputting the focal length value of the zoom mechanism 5, and the aperture value information output means 8 or The movement of the imaging device is detected by an aperture value information output signal or a zoom position information output signal output from the zoom value information output means 10 or both information output means. Wherein by driving the stage 12 two imaging devices B, and controls the imaging position of the C.

  In other words, in consideration of the depth of field, aperture value information during actual use or zoom position information during actual use is arbitrarily set to the maximum aperture value or the minimum aperture value and one to two nearby. Depth of field when it comes to between the aperture value information setting value or between the wide-angle end or telephoto end of the zoom focal length and the zoom position information setting value arbitrarily set slightly before that Is deeper, the imaging device B at the front focus position is controlled along the optical axis so that the imaging device B at the front focus position is further at the front focus position by each information output signal of the aperture value information output means 8 or the zoom value information output means 10 The imaging device C at the rear focus position moves and is controlled and moved along the optical axis so as to be at the rear focus position.

  In addition, when the depth of field is extremely shallow and in an out-of-focus state, the aperture value information during actual use or the zoom position information during actual use is arbitrarily set before the minimum aperture value and one or two of them. When the aperture value information setting value is present, or between the telephoto end of the zoom focal length and the zoom position information setting value arbitrarily set slightly before that, the imaging device at the front focus position The imaging devices C at B and the rear focus position are controlled and moved along the optical axis in the just focus direction, respectively.

  Further, the imaging device moving unit 12 presets either the aperture value information output signal output from the aperture value information output unit 8 or the zoom position information output signal output from the zoom value information output unit 10. When the other set of the information output signal reaches the preset set value when the preset value has been reached and activated, and the depth of field is deep, the imaging device B at the front focus position The image pickup device C at the rear focus position is further controlled and moved along the optical axis so as to be further at the rear focus position.

  As described above, in imaging when the depth of field of the lens is deep, the connection between the two imaging devices B and C is based on the aperture value information output signal during actual use and the zoom position information output signal during actual use. Since the image position is controlled, the depth of field becomes shallower each time, and the slope of the mountain due to the focus voltage approaches a slope suitable for measurement. A process of calculating the level difference of the focus voltage obtained by detecting the high frequency component and increasing or decreasing the driving voltage for controlling the focus driving unit 1 based on the level difference is performed when the level difference is zero or slightly higher than the noise level in advance. Repeat until the threshold value is reached below a preset threshold value, or until the level difference reaches a minimum value that is less than or equal to a preset threshold value slightly higher than the noise level and is obtained within a preset time. Calculation of the level difference processing unit 14 to be executed, even if the noise signal in the high frequency components, easier as a result, quick, and made accurately.

  Further, when the depth of field is extremely shallow, the imaging device moving unit 12 receives the aperture value information output signal output from the aperture value information output unit 8 and the zoom value information output unit 10. When any one of the output zoom position information output signals reaches the preset setting value and is in operation, and when the remaining one of the information output signals reaches the preset setting value, The imaging device B at the front focus position and the imaging device C at the rear focus position are further controlled and moved along the optical axis in the just focus direction.

  Further, as described above, in the out-of-focus imaging when the depth of field is extremely shallow, the two imaging devices B based on the aperture value information output signal during actual use and the zoom position information output signal during actual use. , C image formation positions are controlled, the depth of field becomes deeper each time, and the extreme mountain slope due to the focus voltage approaches a slope suitable for measurement. A process of calculating a focus level difference obtained by detecting the high frequency component output from the component extraction unit 13 and increasing or decreasing the driving voltage for controlling the focus driving unit 1 based on the level difference is zero or , When a threshold value set slightly higher than the noise level is reached or when the level difference is lower than a threshold value set slightly higher than the noise level and within a preset time Calculation of the level difference processing unit 14 that executes repeatedly until a small value is easier as a result, quick, and made accurately.

  In this embodiment, the aperture value information output signal and zoom position information output signal of Embodiment 1 and the distance information output signal from the imaging lens 3 to the subject are also added as one of the parameters, and are calculated from the three information output signals. A means for controlling and moving the imaging positions of the two imaging devices B and C by driving the imaging device moving means 12 based on the depth-of-field information will be described with reference to FIG.

  In the distance measuring camera apparatus of FIG. 3, an imaging device moving unit that enables the two imaging devices B and C mounted so as to be in the front focus position and the rear focus position to move back and forth along the optical axis. 12 and the aperture value information obtained from the aperture value information output means 8, the zoom value information obtained from the zoom value information output means 10, and the distance information to the subject obtained from the distance information output means 2. A depth-of-field detecting means 21 for calculating / detecting the depth-of-field information, wherein the depth-of-field detecting means calculates from the aperture value information, the zoom value information, and the distance information to the subject. The depth information is between the deepest value of the depth-of-field information and the depth-of-field value arbitrarily set near the depth information, and the depth-of-field value arbitrarily set near the shallowest value and the vicinity thereof. Until When adapted to standing, the imaging device moving device 12 is operated, the two imaging devices B, and then control and move the position of the C.

In FIG. 4, when focusing is generally performed on the distance l to the subject, the distance d ₁ that is in focus farther than the distance l is the rear depth of field, and the distance d ₂ that is in focus on the front side is the front depth of field. That's it. Here, the depth of field of the lens is a range d ₁ + d ₂ in which both are combined.

Assuming that the focal length of the lens is f, the F number (aperture value) is F _NO , and the allowable circle of confusion is δ, d ₁ and d ₂ can be expressed by the following equations.
Back depth of field d ₁ = δ · F _NO · l ² / (f ² −δ · F _NO · l)
Forward depth of field d ₂ = δ · F _NO · l ² / (f ² + δ · F _NO · l)

  In the embodiment of the present invention, the maximum depth of field or minimum aperture value, one or two previous aperture values from the above formula, the wide angle end or the telephoto end of the zoom focal length, and Depth of field information calculated from the zoom position slightly ahead, the ∞ distance end and the closest distance end from the imaging lens 3 to the subject, and the distance slightly ahead thereof is set in advance as the depth of field information setting value. In actual use, the depth-of-field information calculated from the aperture value information output signal, the zoom position information output signal, and the distance information output signal to the subject is the deepest value of the depth-of-field information. The imaging device is moved when it exists between a depth of field value arbitrarily set nearby and between a shallowest value and a depth of field value arbitrarily set nearby. Driving means 12 said One of the imaging device B, and then control and move the imaging position of the C.

  That is, when the depth of field is deep, the depth of field information calculated from the large aperture value information during actual use, the wide-angle side zoom position information during actual use, and the ∞ side distance information output signal to the subject. And the plurality of depth-of-field information setting values, and when the calculated depth-of-field information reaches between the depth-of-field information setting values, the imaging device B at the previous focus position further The image pickup device C at the rear focus position is controlled and moved along the optical axis so as to be at the rear focus position.

  Also, when the depth of field is shallow, the depth of field information calculated from the small aperture value information at the time of actual use, the telephoto side zoom position information at the time of actual use and the near side distance information output signal to the subject, and Comparing the plurality of depth-of-field information setting values, and when the calculated depth-of-field information reaches between the depth-of-field information setting values, the imaging device B at the front focus position and the rear focus position Each of the imaging devices C is controlled and moved along the optical axis in the just focus direction.

  Furthermore, in the case of a so-called out-of-focus state where the depth of field is extremely shallow, for example, either an open aperture value information output signal, a telephoto end zoom position information output signal, or a closest distance information output signal to the subject Or the depth-of-field information calculated based on the combination of the two signals reaches the preset depth-of-field information setting value and is already in operation, and another remaining information output signal When the depth-of-field information output signal calculated based on one of the above reaches the preset value, the imaging device B at the front focus position and the imaging device C at the rear focus position are updated respectively. To control and move along the optical axis in the just-focus direction.

The depth-of-field information setting value set in advance in the depth-of-field detection means 21 is to change the focal length by giving priority to the aperture, changing the aperture on the basis of the illumination conditions by giving priority to the focal length, It is preferable to set in consideration of illumination conditions, imaging area, and imaging distance, such as whether to change any of the distances.
The configuration and operation other than those described above are the same as those in the first embodiment.

  In the present embodiment, when the imaging lens 3 is a large lens, a method of moving three lightweight and easily movable imaging devices instead of a method of driving and focusing the large focus lens group 6 to obtain distance information. This is a distance measuring camera device that is capable of performing an extremely high-speed AF operation and a focusing operation at the same time and outputting a focusing signal indicating that the focusing is achieved and distance information to the subject. This embodiment will be described with reference to the drawings.

  5, in the third embodiment, in addition to the distance measuring camera device of the first embodiment, an imaging device mounted at the just focus position on the optical image exit surface of the 3P prism 11 instead of the focus driving means 1. A also includes an imaging device moving unit 12 that can move back and forth along the optical axis, and an in-focus signal that indicates in-focus and distance information to the subject based on the moving distance of the imaging device A that moves back and forth. Distance information output means 22 for outputting is provided.

  As in the first embodiment, each solid-state imaging device performs photoelectric conversion, the A / D conversion circuit converts the analog signal into a digital signal, and only the high frequency component of the video signal output from the camera circuit is extracted by the HPF. Then, the high frequency component in the focus detection area set near the center of the screen by the gate circuit is detected by the detector, and the focus voltage corresponding to the high frequency component of the video signal is output from the detector.

  Since the focal voltage corresponds to the definition of the optical image captured by the imaging lens 3, the focal voltage value appearing in the detector output is a state where the position of the imaging device A matches the distance to the subject. Then, as shown in FIG. 2, the focus voltage of the image pickup device A is at the A position indicating the maximum value Va, and the focus voltage of the image pickup device B mounted at the front focus position is the B position indicating Vb and is at the rear focus position The focal voltage of the mounted imaging device C is a C position indicating Vc.

  The level difference processing unit 14 samples and holds the focus voltage of the detector output at regular time intervals. If the focus voltage is increasing with respect to time, the positive voltage is decreased, and the focus voltage is decreased with time. The imaging device moving voltage output from the level difference processing unit 14 is converted from a digital signal to an analog signal by the D / A conversion circuit and input to the imaging device moving unit 12. Is done. If the imaging device moving voltage of the level difference processing unit 14 is positive, the imaging device moving unit 12 controls and moves the position of the imaging device A to the 3P prism side by the imaging device moving unit 12, for example. If the imaging device moving voltage is negative, the imaging device moving means 12 controls / moves the imaging device A position in the reverse direction.

In other words, the level difference of the focus voltage obtained by detecting the high frequency component extracted from the video signal by the imaging devices B and C attached to the front focus position and the rear focus position output from the high frequency component extraction unit 13 is calculated. Then, the process of increasing or decreasing the imaging device moving voltage for controlling the imaging device moving unit 12 based on the level difference is performed when the level difference reaches zero or below a preset threshold value, or when the level difference is zero. Alternatively, the in-focus position of the imaging device A is determined by repeatedly executing the process until it reaches a minimum value that is equal to or less than a preset threshold value and is obtained within a preset time. At the same time, the imaging devices B and C are controlled and moved in conjunction with the imaging device A while maintaining the relative positions of the front focus position and the rear focus position.
The in-focus position is determined as described above, and a voltage value (analog or digital signal) from a position detection sensor (for example, a potentiometer or an optical rotary encoder) of the image pickup device A is fed back to the distance information output means 22, and the distance information From the output means 22, it outputs from the output terminal 23 as distance information.
The configuration and operation other than those described above are the same as those in the first and second embodiments.

  As another application example, the distance information to the subject can be obtained continuously by tracking and detecting the high frequency component of the subject image moving in the perspective direction within the in-focus region in units of frames. Distance information that can determine whether the subject is approaching or moving away can be output.

  When the imaging devices A, B, and C are all configured with monochrome imaging devices, an imaging device with an extremely high number of pixels can be used. Therefore, even in the case of a high-definition image method, mechanical vibrations are applied to the AF method. Since it does not use a mechanism, it can perform instantaneous high-speed calculation processing, so it can provide an automatic ranging camera device that can output accurate distance information to the subject instantly and can control the just focus position with high-quality images. .

  When the imaging devices A, B, and C are all configured by a color imaging device, a color imaging device having a high pixel count can be used, and a high definition image system such as a color HDTV broadcasting system can be supported. Since no mechanical vibration mechanism is used in the AF method, instantaneous high-speed calculation processing is possible, so accurate distance information to the subject can be output instantaneously, and high-quality images can be controlled to the just focus position. A color type automatic ranging camera device can be provided.

  The imaging device is a color imaging device A with a high pixel number attached at the just focus position, and a monochrome imaging device B, C with an ultra-high pixel number attached at the front focus position and the rear focus position. If configured, it is compatible with high-definition image systems such as color HDTV broadcast systems, and since no mechanical vibration mechanism is used in the AF system, instantaneous high-speed calculation processing is possible, so the subject can be reached instantly. Thus, it is possible to provide an automatic ranging camera device that can output accurate distance information and can obtain a color image output that can be controlled to a just-focus position with a high-quality image.

  In the above description, the light is dispersed and imaged on the three imaging devices A, B, and C mounted on the respective emission surfaces via the 3P prism 11 spectroscopic optical system constituted by the three prisms. The spectral distribution amount may be equal or 70% for the imaging device A at the just-focus position, and 15% for each of the other two imaging devices B and C.

  In addition, if an imaging device having sensitivity in the infrared region or ultraviolet region is used, an automatic ranging camera device that outputs accurate distance information in each light beam region can be provided.

  If an area sensor is used in the imaging device, it can easily cope with NTSC, PAL broadcasting systems, and HDTV and high-definition image systems that require high image quality by capturing and scanning the subject on the surface. It is possible to construct a system that is small in size including equipment and low in cost. Furthermore, as an application example, it can be used as an optimum device for instantaneous high-speed focusing calculation processing without blurring and flicker due to wobbling for FA (factory automation) applications that require high-speed focusing time.

  If a linear sensor is used for the imaging device, sub-scanning means and a memory that are orthogonal to the scanning direction of the imaging device are required. However, since an image with a high number of pixels can be obtained in both the horizontal and vertical scanning directions, It can be used as an automatic ranging camera device that performs high-speed focusing calculation processing based on accurate image data and outputs extremely accurate distance information.

1 is a block diagram of a distance measuring camera device according to Embodiment 1 of the present invention. Explanatory drawing of the autofocus system of the same Example. The block diagram of the ranging camera apparatus of the Example 2. FIG. Explanatory drawing of the back and front depth of field of the Example 2. FIG. The block diagram of the ranging camera apparatus of the Example 3. FIG. The block diagram of the prior art of the ranging method of "mountain climbing servo system". FIG. 6 is a graph showing a focus voltage and a difference hold circuit output voltage curve of an autofocus method using a conventional hill-climbing servo method.

Explanation of symbols

1: Focus drive means 2, 22: Distance information output means 3: Imaging lens 4: Lens aperture mechanism 5: Zoom mechanism 6: Focus lens group 7: Aperture drive means 8: Aperture value information output means 9: Zoom drive means 10: Zoom value information output means 11: 3P prism 12: imaging device moving means 13: high-frequency component extracting section 14: level difference processing section 15: motion vector detecting means 16: gate area control means 17: contour signal superimposing circuit 18: main line output 19: Monitor output 20, 23: Output terminal 21: Depth of field detection means 101: Imaging lens 102: Focus lens group 103: Imaging device 104: Camera circuit 105: Output terminal 106: High-pass filter 107: Detector 108: Difference Hold circuit 109: Drive device controller 110: Drive device

Claims (15)

An imaging lens having a focus driving unit for driving the focus lens group and a distance information output unit to the subject, a spectroscopic optical system that branches an optical image captured by the imaging lens in at least three directions, and 3 of the spectroscopic optical system An imaging device mounted on each of the optical image emitting surfaces, and when one of the imaging devices is at the focal position of the imaging lens, the other two are mounted in total 3 so as to be in the front focus position and the rear focus position, respectively. An image pickup device, three sets of camera circuits for forming a subject signal photoelectrically converted by the image pickup device into a video signal, and a video signal output from the camera circuit and an arbitrarily set combination in one frame screen A high-frequency component extraction unit that extracts a high-frequency component of a subject image obtained from the focus detection region, and the front focus position and the rear focus position extracted by the high-frequency component extraction unit A focus control voltage level difference obtained by detecting a high frequency component of each video signal obtained from the focus detection area of the two imaging devices mounted so as to be, and based on the level difference, the focus A level difference processing unit that repeatedly executes increase / decrease of the drive voltage for driving the drive means until the level difference becomes zero or less than a preset threshold value,
The distance information output means to the subject always outputs the distance information to the subject, and at the same time indicates that the level difference processing unit has focused when the level difference becomes zero or less than a preset threshold value. A ranging camera device characterized by outputting a focusing signal.   The level difference processing unit calculates a level difference of a focus control voltage obtained by detecting a high frequency component of each video signal obtained from the focus detection area, and drives the focus driving unit based on the level difference. The distance measurement according to claim 1, wherein the increase / decrease of the drive voltage is repeatedly calculated until the level difference is zero or less than a preset threshold value and reaches a minimum value obtained within a preset time. Camera device.   The ranging camera device according to claim 1 or 2, wherein the focus detection area is set in the vicinity of the center of the one-frame screen.   In the ranging camera device, a plurality of motion detection areas having the same area as the focus detection area are set so as to surround the focus detection area in one frame screen, and the focus detection area and the plurality of focus detection areas A motion vector detecting means for calculating a level difference between image data of a previous field and a current field of a pixel located in the center of each motion detection area and detecting a motion vector of a subject to be imaged in the focus detection area; 4. A gate area control means for moving the focus detection area and the plurality of motion detection areas in accordance with a motion vector of the subject to be imaged detected by a vector detection means. The ranging camera device according to any one of the above.   The gate region control means generates a contour signal indicating the contour of the focus detection region, and inputs the contour signal to a contour signal superimposing circuit provided at one output terminal of the three sets of camera circuits. 5. The distance measuring camera device according to claim 4, wherein a current position of the focus detection area can be displayed by superimposing and outputting a contour signal on an output video signal of the camera circuit. . In the distance measuring camera device, an imaging device moving unit that enables the two imaging devices mounted so as to be in the front focus position and the rear focus position to move back and forth along the optical axis, and an aperture mechanism of the imaging lens Aperture drive means for driving the aperture value, and aperture value information output means for outputting aperture value information of the aperture mechanism,
The aperture mechanism is driven manually or automatically via the aperture drive means, and the aperture value obtained from the aperture value information output means is between the maximum open value and an aperture value arbitrarily set near the aperture value, and The imaging device moving means is activated when the maximum aperture value is between the maximum aperture value and an aperture value arbitrarily set near the maximum aperture value, and the positions of the two imaging devices are controlled and moved. The distance measuring camera device according to claim 1, wherein: In the distance measuring camera apparatus, the imaging lens includes a zoom mechanism, a zoom driving unit that drives the zoom mechanism, and a zoom value information output unit that outputs focal length value information of the zoom mechanism,
The zoom mechanism is driven via the zoom driving means, and the zoom value of the zoom mechanism obtained from the zoom value information output means is between the wide angle end and a zoom value arbitrarily set near the wide angle end, and telephoto The imaging device moving means is activated when the zoom lens is located between an end and a zoom value arbitrarily set in the vicinity thereof, and the positions of the two imaging devices are controlled and moved. The ranging camera apparatus according to claim 1.   The imaging device moving unit is in a state of being operated by either the aperture value information of the aperture mechanism obtained from the aperture value information output unit or the zoom value information obtained from the zoom value information output unit, When the remaining information becomes a value for driving the imaging device moving means, the imaging device moving means operates corresponding to two pieces of information, and controls and moves the positions of the two imaging devices. The ranging camera apparatus according to claim 1, wherein In the distance measuring camera apparatus, an imaging device moving unit that further moves the two imaging devices mounted so as to be in the front focus position and the rear focus position back and forth along the optical axis, and the aperture value information Object that calculates and detects depth-of-field information based on aperture value information obtained from the output means, zoom value information obtained from the zoom value information output means, and distance information to the subject obtained from the distance information output means With depth of field detection means,
The depth-of-field detection means calculates the depth-of-field information calculated from the aperture value information, the zoom value information, and the distance information to the subject. When the imaging device moving means is present between an arbitrarily set depth of field value and between the shallowest value and an arbitrarily set depth of field nearby, 6. The distance measuring camera device according to claim 1, wherein the distance measuring camera device operates and controls and moves the positions of the two imaging devices.   In the distance measuring camera apparatus, in place of the focus driving unit, an imaging device moving unit that allows an imaging device mounted so as to be a focal position of the imaging lens to move back and forth along the optical axis; The distance information output means which outputs the distance information to a to-be-photographed object based on the moving distance of the imaging device which moves back and forth by an imaging device moving means is provided. The described ranging camera device.   The ranging camera apparatus according to claim 1, wherein all of the imaging devices are monochrome imaging devices.   The ranging camera apparatus according to claim 1, wherein all of the imaging devices are color imaging devices.   One of the imaging devices mounted so as to be the focal position of the imaging lens is a color imaging device, and two mounted so as to be the front focus position and the rear focus position are monochrome imaging devices. The ranging camera apparatus according to claim 1, wherein   The ranging camera device according to claim 1, wherein the imaging device is an area sensor. The ranging camera apparatus according to claim 1, wherein the imaging device is a linear sensor.