JP2007279334A - Imaging apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an imaging apparatus in which a focus ring can be surely rotated in a focusing direction in a focus assist function for assisting manual focus operation for manually adjusting the focus ring. <P>SOLUTION: A front focus evaluation part 131 and a back focus evaluation part 132 respectively extract front focus information and back focus information from sub-imaging parts 111, 112 which are arranged so as to optically hold a main imaging part 110 between them in an optical axis direction. Focused state markers 161, 162 generated from a marker generation part 140 on the basis of these information are arranged in the relation of rotationally symmetrical positions to each other and focusing can be achieved by rotating the focus ring 101 in a direction where the focused state markers 161, 162 are aligned to a focusing reference line 163. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an imaging apparatus such as a television camera, and in particular, has a so-called focus assist function for assisting focus adjustment during manual focus (MF) in which focus adjustment is performed manually by manually rotating a focus ring. The present invention relates to an imaging apparatus.

  In recent years, with the progress of HD (high definition) in television broadcasting, there are increasing opportunities for shooting with HD-capable imaging devices. However, focusing on a small screen of the viewfinder (VF) (focusing operation) has become difficult as the captured image becomes higher in definition. For this reason, an imaging device having a so-called focus assist function that supports manual focusing using a VF screen has been proposed.

  For example, methods such as enlarging and displaying a part of the screen, increasing the level of the contour emphasis signal, and displaying the amount of high-frequency components in a graph have been proposed.

  A conventional imaging apparatus will be described below.

  2. Description of the Related Art Conventionally, for example, an imaging apparatus having a focus assist function is disclosed in Patent Document 1. The configuration of the imaging apparatus is shown in FIG.

  In FIG. 7, reference numeral 200 denotes a focus lens in the lens unit, which moves by turning a focus ring (not shown). Reference numeral 201 denotes a focus position detection unit. An imaging unit 210 converts an optical image incident on the imaging surface from the lens unit into an electrical video signal. The video signal output from the imaging unit 210 is subjected to various video signal processing necessary as a video camera by the camera processing unit 220 and is sent to the display unit 250. On the other hand, the contrast value calculation unit 230 calculates a contrast value indicating the focus level of the image captured by the imaging unit 210. The pattern generation unit 240 generates a pattern to be displayed on the display unit 250 based on the focus position and contrast value detected by the focus position detection unit 201.

A pattern for focus assist generated by the pattern generator 240 is, for example, as shown in FIG. If the focus ring is turned when the subject is not in focus as in the left screen example, the triangle pattern indicates the focus position change direction, which is determined from the focus position change direction and the focus level change direction, and the focus level increases. 261 is displayed. The focus ring is rotated according to the instruction of the triangular pattern 261, and the circle pattern 260 is displayed when it is determined that the focus level has reached the maximum value, that is, the focus position is the focus position.
Japanese Patent Laying-Open No. 2005-140943 (paragraph numbers 0032-0043, FIG. 5)

  However, in the conventional configuration described above, it is impossible to distinguish whether the change in focus level is caused by moving the focus position by rotating the focus ring, or because the picture being photographed itself is changed. There is a problem that it is difficult to surely adjust the focus position at which the focus level becomes the maximum value. In addition, since the relationship between the display pattern indicating the direction in which the focus position is changed for focusing and the rotation direction of the focus ring is not intuitive, the focus ring is erroneously turned in the opposite direction to the focus direction at the beginning of rotation. There was a case.

  The present invention solves the above-mentioned conventional problems, and an image pickup apparatus that can reliably rotate the focus ring in the in-focus direction without being affected by a change in the picture being photographed during manual focus. The purpose is to provide.

  The invention according to claim 1 of the present invention is an imaging device that includes a lens unit and a focus ring for moving a focus lens in the lens unit, and performs focus adjustment by manual operation. A focus evaluation unit that outputs the focus level of the rear pin state as an evaluation value, a marker generation unit that generates a focus state marker indicating the rotation direction of the focus ring from the output of the focus evaluation unit, and A display unit for displaying a focus state marker, wherein the focus state marker includes a plurality of markers arranged in a rotationally symmetrical positional relationship, and the pattern displayed by the marker display It has the effect that the direction of rotation of the focus ring in the in-focus direction can be grasped intuitively without being influenced by.

  The invention according to claim 2 is characterized in that a target index indicating the position of the in-focus state marker at the time of focusing is displayed on the display unit, and the determination of the in-focus point is surely and easily performed. Has the effect of being able to.

  In the invention according to claim 3, the marker generation unit further generates a focus determination area marker indicating an area where the focus determination of the captured image is performed, and the focus state marker and the focus determination area marker The display is displayed on the display unit in an integrated or adjacent manner, and has an effect that the focus assist information can be viewed while gazing at the photographing target.

  As described above, the present invention provides an excellent effect that the rotation direction of the focus ring in the in-focus direction can be reliably transmitted to the cameraman in the manual focus operation, and the determination of the in-focus point can be performed reliably and easily.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram of an image pickup apparatus according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a main image pickup unit and a sub image pickup unit, FIG. 3 is an explanatory view of a focus state, and FIG. FIG. 5 and FIG. 6 are diagrams showing examples of VF display of the image pickup apparatus.

  In FIG. 1, reference numeral 100 denotes a lens unit, and reference numeral 101 denotes a focus ring for moving a focus lens (not shown) in the lens unit 100.

  110 is a main imaging unit, 111 is a sub-imaging unit for front pin evaluation, and 112 is a sub-imaging unit for rear pin evaluation. An optical image incident on the imaging surface after entering from the lens unit 100 is electrically Convert to video signal. Reference numeral 120 denotes a camera processing unit for performing various video signal processing necessary as a video camera, and 131 and 132 denote a front pin evaluation unit and a rear pin evaluation unit, which respectively evaluate the focus levels of the front pin state and the rear pin state. Output as a value. Reference numeral 140 denotes a marker generating unit that generates a marker to be displayed on the display unit 150.

  The operation of the imaging apparatus of the present embodiment configured as described above will be described.

  The video signal output from the main imaging unit 110 is subjected to various signal processing necessary as a video camera by the camera processing unit 120 and sent to the display unit 150.

  On the other hand, the video signals output from the sub-imaging units 111 and 112 are converted into the front pin evaluation value and the rear pin evaluation value indicating the focus level by the front pin evaluation unit 131 and the rear pin evaluation unit 132, respectively. Then, a marker to be displayed on the display unit 150 is generated by the marker generation unit 140 based on the relationship between the front pin evaluation value and the rear pin evaluation value.

  Here, the positional relationship between the main imaging unit 110 and the sub-imaging units 111 and 112 shown in FIG. 1 schematically shows an optical positional relationship. In practice, for example, as shown in FIG. The optical paths are divided using the same, and the image pickup surfaces of the sub image pickup units 111 and 112 are equivalently arranged so as to sandwich the image pickup surface of the main image pickup unit 110 with a very small interval in the optical axis direction.

  Here, the front pin is a state in which the subject is in front of the subject to be photographed, and the rear pin is a state in which the subject is in focus far from the subject to be photographed.

  That is, when the main imaging unit 110, the front pin evaluation sub-imaging unit 111, and the rear pin evaluation sub-imaging unit 112 are arranged in the positional relationship as shown in FIG. 2, as shown in FIG. In this state, the subject is focused on the front imaging evaluation sub-imaging unit 111 rather than the main imaging unit 110.

  On the contrary, in the rear pin state shown in FIG. 3C, the subject is in focus toward the rear pin evaluation sub-imaging unit 112 rather than the main imaging unit 110.

  FIG. 4 schematically shows the front pin evaluation value and the rear pin evaluation value when the focus position is changed, and the main image pickup unit 110 is focused between the focus positions at which the peaks are obtained. There is a so-called just pin focus position shown in FIG.

  Here, by appropriately setting the optical distance between the sub-imaging units 111 and 112, the focus position where the front pin evaluation value and the rear pin evaluation value are equal to each other substantially coincides with the just pin position of the main imaging unit 110. Can do.

  Next, the focus state markers generated by the marker generation unit 140 based on the relationship between the front pin evaluation value and the rear pin evaluation value are, for example, 161 and 162 in the VF display example of FIG.

  In FIG. 5, reference numeral 160 denotes an in-focus determination area marker that indicates an image area for which in-focus determination is being performed, and reference numerals 161 and 162 denote in-focus state markers that indicate a focus state, which are arranged in a rotationally symmetrical positional relationship. Reference numeral 163 denotes an in-focus reference line at which the in-focus state markers 161 and 162 are positioned at the time of focusing, and the horizontal position is used as a reference. The rotation center points of the focus state markers 161 and 162 are on this line.

  When (front pin evaluation value−rear pin evaluation value) shown in FIG. 4B has a positive value, the focus state marker is offset upward on the left side and downward on the right side in the VF display screen of FIG. When 161 and 162 are displayed, in the state of the front pin not in focus, the focus state markers 161 and 162 are evaluated from the focus reference line 163 and the front pin evaluation value and the rear pin evaluation as shown in FIG. The offset is displayed according to the difference in value. In the case of a general detachable lens, the focus position changes in the closest direction when the focus ring 101 is turned clockwise toward the subject, and in the infinite direction when the focus ring 101 is turned counterclockwise, as shown in FIG. If the marker display is correct, if the focus ring 101 is rotated counterclockwise in order to align the focus state markers 161 and 162 with the in-focus reference line 163, the focus position moves to the back, as shown in FIG. It comes to focus on the position.

  When the rear pin is selected, the marker display is upside down from that of the front pin. Therefore, the focus position is brought close by turning the focus ring 101 clockwise to align the in-focus markers 161 and 162 with the reference line 163 at the time of focusing. Move to the side and come into focus.

  In-focus determination is performed on a part of the screen such as the center of the screen. That is, the front pin evaluation unit 131 and the rear pin evaluation unit 132 in FIG. 1 calculate the focus level for a partial region in the screen set in advance. Therefore, by displaying a focus determination area marker 160 indicating the video area for which focus determination is being performed and capturing the target subject there, the cameraman can selectively focus on the target subject. Can do.

  As described above, according to the present embodiment, when the focus is manually adjusted, the markers offset according to the shift of the focus position from the focus position are arranged and displayed in the rotationally symmetrical positional relationship, The direction in which the focus ring 101 is rotated in the in-focus direction can be intuitively notified to the photographer, and the focus ring 101 can be prevented from being rotated in the wrong direction.

  Further, depending on the pattern displayed on the VF, the target horizontal position may be difficult to understand. In such a case, the in-focus state markers 161 and 162 are aligned horizontally by displaying the in-focus reference line 163, which is a display serving as a horizontal reference, together with the in-focus state markers 161 and 162. That is, it is easy to recognize that the focus position is at the in-focus position, and the focus position can be accurately adjusted to the in-focus position.

  Note that the marker position at the time of focusing is not limited to the horizontal alignment as in the present embodiment, but it is not limited to the vertical alignment, or the four marker markers are arranged in a cross to align the horizontal and vertical. It is sufficient if the arrangement is easy to understand intuitively.

  In the above description, the in-focus reference line 163 in FIG. 5 is indicated by a continuous broken line. This is not necessarily the case.

  Also, if the focus status display is at a position far from the image area where focus is determined, such as the bottom edge of the screen, the cameraman's line of sight when focusing is off the subject in the center of the screen. Although not preferable, as in the present embodiment, the in-focus state markers 161 and 162 that indicate the focus state and the in-focus determination region marker 160 that indicates the image region in which the in-focus determination is performed are adjacent or integrated. By displaying in such a manner, it is possible to minimize the movement of the cameraman's line of sight during focusing. That is, it is possible to simultaneously see the in-focus state marker for focusing while gazing at the subject.

  Further, the display and movement of the in-focus state marker can be made to coincide with the feeling of turning the focus ring by adopting a form along a circle simulating the focus ring 101 as shown in FIG.

  Moreover, although the case where the focus determination area | region marker showing the image area | region which performs focus determination was enclosed by the rectangle with the straight line was shown, the shape of an area | region is not restricted to a rectangle, It is circular as shown in FIG. The method is not limited to this, for example, by expressing the brightness by changing the brightness inside or outside the area without being surrounded by a line.

  The image pickup apparatus according to the present invention is useful as an image pickup apparatus having a focus assist function that can reliably rotate the focus ring in the in-focus direction when focusing is performed manually.

1 is a block diagram of an imaging apparatus according to an embodiment of the present invention. 1 is a configuration diagram of a main imaging unit and a sub imaging unit of an imaging apparatus according to an embodiment of the present invention. Explanatory drawing of the focus state of the imaging device in one embodiment of the present invention The graph which shows the relationship between the focus position of the imaging device in one embodiment of this invention, and a focus level The figure which shows the example of VF display of the imaging device in one embodiment of this invention The figure which shows the example of VF display of the imaging device in one embodiment of this invention Block diagram of an image pickup apparatus having a conventional focus assist function The figure which shows the example of VF display of the imaging device provided with the conventional focus assist function

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Lens unit 101 Focus ring 110 Main imaging part 111 Front pin evaluation sub imaging part 112 Rear pin evaluation sub imaging part 131 Front pin evaluation part 132 Rear pin evaluation part 140 Marker generation part 150 Display part 160 Focus determination area marker 161 , 162 In-focus state marker 163 In-focus reference line 200 Focus lens 201 Focus position detection unit 210 Imaging unit 230 Contrast value calculation unit 240 Pattern generation unit 250 Display unit

Claims (3)

An imaging apparatus having a lens unit and a focus ring for moving a focus lens in the lens unit, and performing focus adjustment manually.
A focus evaluation unit that outputs the focus levels of the front pin and rear pin states as evaluation values,
A marker generating unit that generates a focus state marker indicating a rotation direction of the focus ring from an output of the focus evaluation unit;
A display unit for displaying the in-focus state marker;
The in-focus state marker includes a plurality of markers arranged in a rotationally symmetrical positional relationship with each other. The imaging apparatus according to claim 1, wherein a target index indicating a position of the in-focus state marker at the time of focusing is displayed on the display unit. The marker generation unit further generates a focus determination area marker indicating an area for performing focus determination of the captured image,
The imaging apparatus according to claim 1, wherein the display of the in-focus state marker and the in-focus determination area marker is displayed on the display unit in an integrated or adjacent manner.

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