JPH05207355A - Image pickup device - Google Patents

Abstract

PURPOSE:To attain a speedy focusing by indicating that a lens holder is positioned at a movement limitation edge. CONSTITUTION:At the time of operating a focusing or the like by a manual operation, a control means 16 is appropriately operated. When the manual signal is outputted to a control means 17, and a motor 10 is operated, a lens holder 9 is moved along an optical axis C in a lens barrel 2, and a display 20 indicating the manual operation mode is operated at a view finder 19. In the manual operation mode, information from edge part detecting means 14 and 15 is fetched in the control means 17, and when the lens holder 9 is positioned at the movement limitation edge of a near edge part or a distant edge part for the lens barrel 2, a signal from the edge part detecting means 14 and 15 is identified by the control means 17, and the display 21 indicating that the lens holder 9 can not be further moved is operated at the view finder 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, an image pickup apparatus having an inner focus type lens barrel, and particularly when performing manual focusing, a focus limit operation is performed by displaying a lens movement limit end on a viewfinder. The image pickup apparatus is capable of quickly performing.

[0002]

2. Description of the Related Art In a video camera, for example, an inner focus type zoom lens barrel for performing focusing, correction, and image formation by moving a master lens group for focusing and a variator lens group for zooming along an optical axis. In such a lens barrel, a so-called autofocus system is also adopted, which automatically adjusts focusing, correction, and image formation of a read image. As an image pickup apparatus of the autofocus system, for example, a point where the high frequency component level of the video signal in the image frame has a peak, that is, the point where the contrast is the strongest is determined as the optimum focusing point, and based on this data There is known a so-called peak hold detection method in which a focusing master lens group is moved by a stepping motor or the like.

Further, in the autofocus type image pickup apparatus, since the focusing master lens group is moved so as to focus a specific point in the image frame, a portion other than the point is read. When it is desired to focus an image, the automatic control can be released to manually focus on a desired position.

[0004]

However, in the conventional video camera, when the focus is manually adjusted, the operator cannot know the moving position of the focus master lens, and the lens is close to the near end portion. Or, even when moving to the far end, it was not uncommon to continue the operation. Therefore, the read image cannot be quickly focused, and the image is taken for a long time in a defocused state, so that a satisfactory image cannot be obtained.

The present invention has been made in view of the above problems of the prior art, and by urging the operator to know the position of the movable lens group, particularly the movement limit end, during manual operation, An object of the present invention is to provide an imaging device that can quickly focus.

[0006]

In order to achieve the above object, in an image pickup apparatus of the present invention, a lens holder holding a lens is provided inside a lens barrel along an optical axis, and the lens holder is moved by a lens moving means. In the moving imaging device,
An operating unit that outputs a manual signal to the lens moving unit, an end detecting unit that detects a movement limit end of the lens holder, and an operation of the lens moving unit based on a signal from the operating unit. , A control means for outputting a display command signal to a display means based on a signal from the edge detection means, and a signal from the control means,
And a display unit for displaying a display indicating that the lens holder is located at the movement limit end in the visual field of the operator.

[0007]

When the automatic control is released and the manual signal is output from the operating means, the lens moving means operates to move the lens along the optical axis in the lens barrel, thereby enabling manual adjustment of the focus and the like. When the lens holder is located at the movement limit end with respect to the lens barrel, this state is detected by the end detection means, and a signal of this state is output to the display means via the control means. Then, the operator is informed of this state by performing a display indicating that the lens holder is located at the movement limit end in the operator's visual field.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an image pickup apparatus which is an embodiment of the present invention, FIG. 2 is a perspective view showing an edge detecting means of the embodiment,
FIG. 3 is a front view showing the display means of the embodiment.
FIG. 3A is a front view showing the display means during manual operation.
FIG. 4B is a front view showing the display means at the movement limit end, and FIG. 4 is a flow chart showing the control procedure in the control means of the embodiment.

The inner focus type lens barrel 1 shown in FIG. 1 has a cylindrical lens barrel 2, and a focusing lens group 3 is fixed to the tip of the lens barrel 2.
Further, a pair of guide shafts 4a, 4a are provided near the focusing lens group 3, and a lens holder 6 holding a variator lens group 5 for zooming (magnification) moves along the optical axis C. It is provided freely. The zoom variator lens group 5 may be configured to be moved by a manual operation, or may be configured to be moved by a motor similarly to the focusing master lens group 8 described later.

A CC attached to the base end of the lens barrel 2
A pair of guide shafts 4b, 4b is provided in the vicinity of D (charge couple device) 7, and a cylindrical lens holder 9 holding a master lens group 8 for focusing is provided on the guide shafts 4b, 4b. It is provided so as to be movable along 4b. When the lens holder 9 moves along the guide shaft 4b, the optical axis of the master lens group 8 for focusing held by the lens holder 9 moves while being aligned with the optical axis C of the lens barrel 2. There is.

In order to move the lens holder 9 holding the master lens group 8 for focusing, the lens barrel 2
Is a motor 10 that can rotate in both directions (lens moving means)
Is fixed, and a female screw 23 that meshes with a male screw 22 fixed to the tip of the rotating shaft 10 a is attached to the lens holder 9 via a bracket 24. Therefore, when the rotation shaft 10a of the motor 10 rotates in either direction by the signal from the control means 17, the lens holder 9 is guided by the lens holder 9 via the male screw 22 and the female screw 23.
It moves forward or backward along with to adjust the focus according to the read image.

The image pickup apparatus of this embodiment is provided with edge detecting means 14 and 15 for detecting the movement limit edge of the focusing master lens group 8 described above. As shown in FIG. 2, the edge detecting means 14 and 15 are composed of a light shielding plate 11 provided on the lens holder side 9 and a photo interrupter 12 provided on the lens barrel side 2. That is, the photo interrupter 12 is arranged so as to oppose the light emitting element 1 with the movement path of the light shielding plate 11 interposed therebetween.
2a and the light receiving element 12b
A signal of logic "0" is output when b is in the light receiving state, and a signal of logic "1" is output when b is in the light shielding state, and the output signal from the light receiving element 12b is input to the control means 17. It is wired to be done.

In this embodiment, end detection means 14 and 15 for detecting the forward limit and the backward limit of the lens holder 9, that is, the proximity limit and the infinite limit of the lens group 8 are provided, respectively. As shown in FIG. 1, the lens holder 9 is provided with one light shielding plate 11, and the lens barrel side 2 is provided with two photo interrupters 12 and 13. When the lens holder 9 is located at the forward limit, the photo interrupter 13 is shielded from light by the light blocking plate 11, while when the lens holder 9 is located at the backward limit, the light blocking plate 11 is blocked.
The photo interrupter 12 is thus shielded from light. Output signals from the photo interrupters 12 and 13 are input to the control means 17 and then output to the display means 18 to perform a predetermined display.

The edge detecting means 14, 15 of the present invention
Is not limited to the above-mentioned embodiment, and may be any means that can detect the forward limit and the backward limit of the lens holder 9, respectively. For example, one photo interrupter may be attached to the lens holder side 9 and two light shielding plates may be attached to the lens barrel side 2 to configure the end detecting means. Further, instead of the light shielding plate, a magnet may be attached to the lens holder side or the lens barrel side, and a hall element may be attached to the lens barrel side or the lens holder side to configure the end portion detection means. Further, it is possible to use other proximity sensors, and in addition to such a non-contact sensor, a contact type sensor may be used.

The image pickup apparatus of this embodiment employs a so-called autofocus method, and the point where the high frequency component level of the video signal in the image frame is at the peak, that is, the contrast is strongest is optimum. The focusing point is determined and the focusing master lens group 8 is moved to an appropriate position based on this data. Further, in such an autofocus mode, since the focusing master lens group 8 is moved so as to focus a specific point within the image frame, the focus of the read image is focused on a portion other than that point. If you want to match, for example, image (imaging range)
The autofocus mode is inconvenient when it is desired to move only the focus point while maintaining the state as it is. Therefore, in such a case, the operator can perform focus adjustment by switching to manual operation.

When performing such focus adjustment by manual operation, operating means 16 for moving the master lens group 8 for focus is provided, for example, in the main body of the image pickup apparatus, and is a push button type or dial type. The operating means can be adopted. The push button type operation means 16 has a button to be input when advancing the focusing master lens group 8 and a button to be input when the focus master lens group 8 is to be moved backward. On the other hand, in the case of the dial type operation means, It is configured such that when it is rotated in either direction, it moves forward, and when it is rotated in the opposite direction, it moves backward.

The signal from the operating means 16 is the control means 1.
7 is input to the motor 10 which is the lens moving means.
The motor may be operated while the operation button is being pressed, or the motor may be operated by a predetermined pulse when the operation button is pressed once.

As described above, the control means 17 according to the present embodiment rotates the rotary shaft 10a of the motor 10 in either direction based on the manual signal from the operating means 16 so as to focus the master lens group 8 for focusing. Is moved forward or backward by a desired distance. Further, when the output signals from the two end detecting means 14 and 15 are in the light-shielded state when the autofocus mode is canceled and the manual operation mode is set, display is performed on the display means 18, which will be described later, that is, the viewfinder. Output a command signal. In addition, in the present embodiment, in addition to this, the automatic focus mode is canceled to indicate that the manual operation mode is set. For this display, for example, when a release button for the autofocus mode (not shown) is pressed, this signal is taken in by the control means 17 and output to the display means 18, for example a display 20 as shown in FIG. You can go inside 19.

The display means 18 according to the present embodiment is means for performing a predetermined display in order to inform the operator of the limit end of the lens holder 9 detected by the end detection means 14 and 15, for example, a viewfinder. The end portion is displayed at 19. The content of the display is not limited, but a display 21 as shown in FIG. 3 (B) is suitable. In addition, in the present embodiment, the same display 21 is displayed regardless of the end of the master lens group 8 for focusing without distinguishing between the forward limit and the backward limit. Different displays may be displayed. Further, the display position in the viewfinder 19 is not limited at all, and further, the display means 18 for displaying is sufficient as long as it can be displayed within the field of view of the operator when the operator is manually operating. The display means is not limited to the viewfinder 19 and may be provided in another part of the imaging device.

Next, the control procedure of this embodiment will be described with reference to the flow chart shown in FIG. First, when the operator selects the auto focus mode, the point where the high frequency component level of the video signal captured in the image frame is at the peak, that is, the point where the contrast is strongest is determined as the optimum focusing point. Then, based on this data, the focusing master lens group 8 is moved to an appropriate position (steps 1 and 7).

When the automatic focusing mode (automatic control) is released and the focusing is performed manually, the operating means 16 is appropriately operated. This manual signal is output to the control means 17, and the motor 10 operates to move the lens holder 9 in the lens barrel 2 along the optical axis C.
As shown in (A), the display 20 for notifying that it is in the manual operation mode is performed (steps 1 and 5).

In this manual operation mode, the information from the edge detecting means 14 and 15 is fetched into the control means 17 (step 2), but the lens holder 9 is near or far from the lens barrel 2. When it is located at any one of the movement limit ends, the signals from the end detecting means 14 and 15 are transmitted to the control means 1.
7 and from there, the viewfinder 19 is provided with a display 21 as shown in FIG. 3B for notifying that the lens holder 9 will not move any further (steps 3, 4, 6). In this way, the operator knows the current situation by making the display 21 indicating that the lens holder 9 is located at the movement limit end in the operator's visual field and notifying the operator of this state. You will be able to take the following appropriate measures.

In the above-described embodiment, a specific example in which the forward limit and the backward limit are displayed when the master lens group 8 for focusing is manually operated has been described, but the present invention is not limited to this example. For example, the zoom adjustment may be performed quickly by displaying the forward limit and the backward limit when manually operating the zoom variator lens group 5.

The autofocus system of the image pickup apparatus of the present invention is not limited to the peak hold detection system described above, but may be a detection system using an average value or a conventionally known system. Furthermore, the image pickup apparatus of the present invention does not have to have the autofocus mode, but at least has the manual operation mode.

[0025]

As described above, according to the present invention, the fact that the lens holder holding the lens is located at the movement limit end is displayed in the visual field of the operator, so that the manual operation is possible. In, the operator can know that the lens group is at the movement limit position, and by taking the following measures, the focusing operation can be performed quickly.

[Brief description of drawings]

FIG. 1 is a configuration diagram illustrating an image pickup apparatus that is an embodiment of the present invention.

FIG. 2 is a perspective view showing an edge detecting means of the embodiment.

FIG. 3 is a front view showing the display means of the embodiment,
(A) shows a display during manual operation, and (B) shows a display of the movement limit end.

FIG. 4 is a flowchart showing a control procedure in the control means of the embodiment.

[Explanation of symbols]

 2 ... Lens barrel 8 ... Focusing master lens group 9 ... Lens holder 10 ... Motor (lens moving means) 11 ... Light-shielding plate (end detection means) 12 ... Photo interrupter (end detection means) 14, 15 ... End detection Means 16 ... Operating means 17 ... Control means 18 ... Viewfinder (display means) 21 ... Display indicating that it is located at the movement limit end C ... Optical axis

Claims (1)

[Claims] 1. An image pickup device in which a lens holder holding a lens is provided in a lens barrel along an optical axis, and the lens holder is moved by a lens moving means, and an operating means for outputting a manual signal to the lens moving means. And an edge detecting means for detecting a movement limit edge of the lens holder, an operation of the lens moving means based on a signal from the operating means, and a display based on a signal from the edge detecting means. Control means for outputting a display command signal to the means, and display means for displaying, in the operator's visual field, a display indicating that the lens holder is located at the movement limit end based on the signal from the control means. An imaging device characterized by the above.