JPH05113595A - Optical instrument - Google Patents

Abstract

PURPOSE:To prevent blurring from being partially left by setting the control range of a blurring correction means for executing a panning and a tilting actions to be smaller than the maximum movable range of the blurring correction means when the correction of the blurring and the panning and the tilting actions are simultaneously executed. CONSTITUTION:For example, a signal is outputted by a yaw direction panning and tilting operation switch 9' according to the content of the operation thereof. Besides, the blurring of a yaw direction is detected by a blurring detection sensor 46. In a microcomputer 45, two signals are added by an addition part 59. Then, difference between the outputs of appex angle sensor detection circuits 43 and 44 and the output of a target position being the output of the addition part 59 is obtained by a difference detection part 57. According to the obtained value, the quantity of feedback is decided. Then, the feedback is executed to an actuator 48. As for a pitch shaft, the similar constitution is applied. Then, the control range of the appex angle state of a variable appex angle prism 41 from the switches 9 and 9' is set to be smaller than the maximum appex angle of the prism 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device such as a still camera or a video camera provided with a blur correction means for reducing harmful blur of a screen caused by various causes.

[0002]

2. Description of the Related Art In recent years, automation of photographing devices such as still cameras and video cameras has progressed, and various functions such as automatic exposure adjusting means and automatic focus adjusting means have been put to practical use.

Particularly, in a photographing device such as a video camera, it is general to use a zoom lens as a photographing lens used, and the zoom ratio thereof tends to increase year by year.

On the other hand, the miniaturization of the photographing device is also remarkable, and due to the miniaturization of the imaging screen size, the development of high-density mounting technology, the development of a compact recorder mechanical chassis, etc., a small model capable of photographing with one hand appears. Is coming.

However, when a small video camera equipped with such a zoom lens is used, harmful shake of the screen is likely to occur due to camera shake of the photographer. Therefore,
In order to remove this shake and obtain a stable screen, various shake preventing devices have been proposed. If this kind of shake prevention device is used, not only the harmful shake of the screen due to such hand shake, but also in the situation where the harmful shake can not be eliminated even when using a tripod when shooting from a ship or car etc. However, it goes without saying that it has a great effect.

This shake prevention device is configured to include at least shake detection means for detecting shake and shake correction means for performing some correction so that shake does not occur as a screen in accordance with the detected shake information. ing.

As the shake detecting means, for example, an angular accelerometer, an angular velocity meter, an angular displacement meter, etc. are known. As the shake correction means, a variable apex angle prism (details will be described later) by the applicant of the present application, or a video camera configured to cut out an area to be actually used as a screen from the obtained imaging screen information A method of sequentially changing (tracking) the cutout position to a position where shake is corrected is known.

As the shake correction means, a method in which a shake is removed at the stage of an image formed on an image pickup device by using a variable apex angle prism or some other optical means as in the former case is an optical method. The correction method is called, and the latter method of electronically processing the image information including the shake to remove the shake is called the electronic correction means.

Generally, the optical correction means is capable of correcting a shake within an angle defined as a shake angle of a camera regardless of the focal length of the lens, and therefore, the tele side of the zoom lens. Even if the focal length is long, it is possible to have the shake removal performance with no practical problem. However, it has a drawback of increasing the size of the camera.

On the other hand, the electronic correction means has a constant correction rate for the vertical dimension of the screen, for example. Therefore, as the telephoto side focal length becomes longer, the shake removal performance deteriorates. In the case of the electronic type, it is often advantageous for miniaturization.

FIG. 13 is a diagram for explaining the relationship between the focal length and the camera shake angle in terms of the subject position on the screen.

In FIG. 13, the optical axis of the lens when the camera is at the position indicated by 12 is 13, which means that the face of the person 11 who is the subject is almost centered. From this state, it is assumed that the camera is rotated by a degree camera shake. At this time, the camera position is 14 and the optical axis is 15.

FIGS. 13B and 13C show the screen positions at the camera positions of 12 and 14, where FIG. 13B shows the zoom lens at the tele end and FIG. 13C shows the wide end. Indicates the state of. Reference numeral 16 denotes a subject within the screen, 17 and 19 denote screens when the camera position is 12, and 18 and 20 denote screens when the camera position is 14, respectively.

As is clear from FIG. 13, even if the camera shake is the same a degree, naturally, the longer the focal length of the lens, the more harmful the shake on the screen. Therefore, an optical means such as a variable apex angle prism is effective as a shake correction means particularly in combination with a lens having a long focal length at the telephoto end.

FIG. 14 shows the structure of the variable apex angle prism.

In FIG. 14, 21 and 23 are glass plates, and 27 is a bellows portion made of a material such as polyethylene. These glass plates 21 and 23 and the bellows 27
A transparent liquid made of, for example, silicon oil is sealed in the inside surrounded by.

In FIG. 14B, the two glass plates 21 and 23 are parallel to each other, and in this case, the incident angle and the outgoing angle of the light beam of the variable apex angle prism are equal. On the other hand, (A),
When the glass plates 21 and 23 are not parallel to each other as shown in (C), the rays are bent at a certain angle as indicated by rays 24 and 26, respectively.

Therefore, when the camera is tilted due to camera shake or the like, the shake is eliminated by controlling the angle of the variable apex angle prism provided in front of the lens so that the spectral line corresponding to that angle bends. It can be done.

FIG. 15 shows this state. Assuming that the variable apex angle prism is in a parallel state in FIG. 15A and the light beam is catching the head of the subject, the deflection is a degree as shown in FIG. On the other hand, by driving the variable apex angle prism to bend the light beam as shown in the figure, the photographic optical axis remains the same, and the subject's head is continuously captured.

FIG. 16 is a diagram showing an example of an actual configuration of a variable vertical angle prism unit including the variable vertical angle prism, an actuator section for driving the variable vertical angle prism, and a vertical angle sensor for detecting an angular state.

Since the actual shake appears in all directions, the front glass surface and the rear glass surface of the variable apex angle prism are configured to be rotatable about the rotation axes in directions shifted by 90 degrees. Here, the subscripts a and b are used to indicate the respective components in the two rotation directions, but those having the same number have exactly the same function.
Also, some of the parts on the b side are not shown.

Reference numeral 41 is a variable apex angle prism, which is a glass plate 2.
1, 23, the bellows portion 27, the liquid 3 and the like. The glass plates 21 and 23 are integrally attached to the holding frame 28 using an adhesive or the like. The holding frame 28 constitutes a rotary shaft 33 with a fixed component (not shown), and is rotatable around this shaft. The shaft 33a and the shaft 33b are different in the direction of 90 degrees. A coil 35 is integrally provided on the holding frame 28, while the magnet 3 is provided on a fixed portion (not shown).
6, and yokes 37 and 38 are provided. Therefore,
By passing a current through the coil 35, the variable apex angle prism 41 rotates about its axis 33. There is a slit 29 at the tip of the arm portion 30 integrally extending from the holding frame 28,
The light emitting element 31 such as iRED provided on the fixed portion and the PS
An apex angle sensor is configured with a light receiving element such as D.

FIG. 17 is a block diagram showing the combination of a lens and a shake prevention device provided with the variable apex angle prism 41 as shake correction means.

In FIG. 17, 41 is a variable apex angle prism, 43 and 44 are apex angle sensors, 53 and 54 are amplification circuits for amplifying the outputs of the apex angle sensors 43 and 44, 45 is a microcomputer, and 46 and 47 are angles. A shake detecting means composed of an accelerometer and the like, 48 and 49 are provided from the coil 35 to the yoke 38
And 52 are lenses.

In the microcomputer 45, the angular state detected by the apex angle sensors 43 and 44 and the shake detecting means 4
In order to control the variable apex angle prism 41 to an optimal angle state for removing shake according to the detection results of 6 and 47,
The current to be applied to the actuators 48 and 49 is determined.

The main element is made up of two blocks because it is assumed that control in two directions 90 degrees apart is performed independently.

The shake prevention device using the variable apex angle prism has been described above.

In recent years, the above-mentioned correction means for correcting the blurring can be used not only for preventing the blurring but also for moving the subject in the photographing screen in the lateral direction (panning) and the vertical direction (tilting). It has been proposed (JP-A-1-193721).

[0029]

However, when blurring occurs when the blurring correction means is used for panning or tilting, the original blurring prevention function cannot be fulfilled. Further, if it is attempted to simply perform the shake correction and the panning etc. by the correction means, a state in which both purposes cannot be achieved occurs particularly near the correction limit.

[0030]

[Means for Solving the Problems] In order to sequentially move a subject image in a photographic screen, an optical device having a structure for driving a blur correction unit is made to perform the above-mentioned operation and at the same time perform blur correction. It has become possible to move the subject within the shooting screen more smoothly. Further, the range in which the blur correction unit is driven is made smaller than the maximum correction range, whereby the movement of the subject image using the blur correction unit and the blur prevention can be compatible in all ranges.

[0031]

【Example】

(First Embodiment) An embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, when the inclination of the light beam bent by the variable apex angle prism is ± 2 degrees, the image pickup screen size is 1/2 inch, and the height of 170 cm standing at the object distance of 10 m at each focal length. The angle of view when the variable apex angle prism is driven in the pitch direction for a person is shown. In the figure, 1 is a person who is a subject. 3 is +2 degrees, 2 is -2
Indicates the angle of view in degrees. Here we assume 54, 72, 10
The focal lengths of 0, 138 mm are 6 times, 8 times and 10 times, respectively.
It is close to the value that is generally set as the focal length at the tele end of a lens having a zoom ratio of approx.

In particular, assuming a long focus such as 138 mm, even if the camera is fixed to a tripod, for example, if the apex angle is changed at a constant angular velocity, the apex angle is −2 degrees and +2 degrees. Smooth tilting can be performed to the extent that the three screens of 0 degree and 0 degree do not overlap at all.

This effect is obtained when the focal length is long and the tilt of the bent light beam is large.

Conventionally, in order to obtain smooth panning, it was necessary to use a tripod equipped with an electric pan head, but if this function is used, it can be attached to a camera on a general tripod. By operating the switch provided, smooth panning and tilting images can be easily obtained. Also,
Even if the camera is not attached to a tripod, the switch can be operated after the camera position is held constant, so that a better image can be recorded than when the camera is actually shaken for panning and tilting.

FIG. 2 shows an example of the switch configuration on the camera side. The slide switch 4 selects whether to use the variable apex angle prism as the correction means of the shake prevention device or the pan / tilt function according to the present invention. Only when the switch 4 is on the shake prevention device OFF side, the pan, Tilt switch 5
Is accepted. Switch 5 is 4 of 5a-5d
It consists of individual push switches, and tilting can be performed by operating 5a and 5b, and panning can be performed by operating 5c and 5d.

Since the variable apex prism has the rotating shafts arranged in two directions which are deviated by 90 degrees, for example, the switches 5a and 5c are used.
Press simultaneously to drive the actuators in both directions,
The screen can move to the lower right.

In addition to the above, as a switch configuration, when a pan or tilt function is operated without providing a selection switch, it is possible to conclude that the shake prevention device has a higher priority.

FIG. 3 shows an example of display in the electronic viewfinder. Reference numeral 6 denotes a view angle range, and 7 denotes a portion for displaying the state of the variable apex angle prism, which is indicated by arrows 8p and 8t. In the case of the figure, there is an apex angle state near 0 degrees in the tilting direction, and a slightly right side is seen in the panning direction.

FIG. 4 shows a block configuration.

Blocks having the same numbers as in FIG. 17 have the same functions. Reference numeral 9 is an operation switch for performing pan and tilt operations. Reference numeral 10 is an electronic viewfinder, to which information for displaying as shown in FIG. 3 is sent from the microcomputer 45. Reference numeral 56 denotes a selection switch which informs the microcomputer which one of the blur prevention, pan and tilt functions is selected, and which of the outputs of the blur detection means 46 and 47 and the operation state of the selection switch 56 to the microcomputer 45. introduce.

FIG. 5 is a flowchart. Step 1
Start at 01. In step 102, it is determined whether or not the blurring prevention function is selected. In the case of the blurring prevention device, in step 103, the flow for blurring prevention is performed. (Details are omitted.) In the case of the pan / tilt function, whether or not the switch is operated is determined in step 104, and when the switch is not operated, the vertical angle state is held in step 105. When the switch is operated, the operation content is read in step 106, and the actuator is driven in accordance with 107.

(Second Embodiment) When the pan and tilt functions can be moved, if the pan and tilt speeds can be freely switched, it will be a further advantage in drawing. Therefore, the speed can be varied by changing the speed according to the pressing of the switch as shown in FIG. 3 or by arranging another speed adjusting knob and switching the speed.

(Third Embodiment) In the first embodiment, it is premised that the shake prevention device and the pan and tilt functions are selected. However, during the pan operation, the shake prevention is continued only in the pitch direction, and conversely, the tilt is prevented. It is also possible to continue to prevent blurring only in the yaw direction during operation.

FIG. 6 shows a flow chart in this case.
Start at step 108. In step 109, it is determined whether or not the pan and tilt switches have been operated. When there is no operation, it is determined in step 110 whether the shake prevention device is on or off, and if it is off, step 1
At 12, the angular state of the variable apex angle prism at that time is maintained. When it is on, the shake prevention operation is naturally performed in both pitch and yaw directions (step 111).

When a pan or tilt operation is performed, it is determined in step 113 whether the operation is a pan or tilt operation alone. When operating in both directions, the actuator is driven for pan and tilt in both pitch and yaw directions. If the operation is only in the pan or tilt direction, the direction in which the operation is performed is read in step 115, and as a result, in steps 116 and 117, the blurring prevention device continues only in the direction in which the pan or tilt operation is not performed. Operate.

(Fourth Embodiment) In all of the above-mentioned first to third embodiments, the actuator for changing the apex angle of the variable apex angle prism is constructed so as to correspond to either the pan or the tilt function or the anti-shake device. Therefore, if the pan / tilt function is used while holding a certain direction in a handheld state or the like, the camera shake that occurs when holding the certain direction cannot be removed.

In the fourth embodiment, a configuration is presented in which the shake prevention device always operates even when the pan and tilt functions are used.

FIG. 7A shows how the vertical angle changes when the panning switch is operated in the first to third embodiments, with the time on the horizontal axis and the vertical angle on the vertical axis.

FIG. 7B shows the result of detection by the shake detection sensor of the shake that occurs in the yaw direction when the camera is held in the fixed direction for the same period of time. Therefore, in the fourth embodiment, as a result of adding FIG. 7A and FIG.
By driving the actuator in the relationship between time and apex angle as shown in (c), it is possible to perform panning while preventing blurring.

FIG. 8 shows a block diagram of a shake prevention device having a pan and tilt device suitable for the fourth embodiment.
In the figure, among the operation switches, those associated with the yaw side drive (FIGS. 2, 5a5b) are 9 ', and those associated with the pitch side operation (FIGS. 2, 5c5d) are 9. For example, when a pan / tilt operation in the yaw direction is performed by the switch 9 ', a signal as shown in FIG. 7A is issued from 9'according to the operation content. The output of the shake detecting means in the yaw direction is detected by the shake detecting sensor 46 as shown in FIG. 7 (B). In the microcomputer 45, these two signals are added by the addition unit 5
9, the output from the apex angle sensor detection circuit 53 and the target position output which is the output of the adder 59 are obtained by the difference detector 57, the feedback amount is determined according to this value, and the actuator 48 You will be back to feet. The pitch axis has the same configuration.

FIG. 9 shows an example of a flow chart of the microcomputer 45 when carrying out the fourth embodiment.

FIG. 9 is a main flow, in which the vertical angle target position signal from the shake detecting means 46 is B pan and the vertical angle target position from the tilt operation 9'is A.

In step 202, the target value B from the blur detecting means is read in step 203, and the target value A from the tilt device is read. In step 204, a signal C = A + B is calculated by adding them. At 205, the current vertical angle state C'of the variable vertical angle prism is detected, and at 206, the difference Δ between the current position C'and the target position C is obtained.

At 207, the gain K is multiplied according to this Δ to calculate the voltage deviation amount (feedback amount) to the actuator, and at step 208, the applied voltage is determined.

The above is the flow of the fourth embodiment.

The screen obtained in the fourth embodiment can be expected to be a stable screen without the above-mentioned drawbacks because the output of the blur detection sensor can be only the pure blur component not including the panning component. ..

In the above description of the embodiments, the variable apex angle prism is used as the correction means of the shake prevention device, but it goes without saying that the present invention can be implemented by other methods.

(Fifth Embodiment) In the present and fourth embodiments, the apex angle state of the variable apex angle prism is added to both the detection result of the blur detection sensor and the operation results of the pan and tilt operation switches 9 and 9 '. It was shown to control.

In the fourth embodiment, when the result of adding the two signals shows a value exceeding the maximum apex angle of the variable apex angle prism, blurring remains as a result. For example, in FIG. 7C, the result of adding the two signals is 61.
When the command is to control the apex angle state as in the above, at the time t which exceeds the maximum apex angle of 5 ° of the variable apex angle prism,
The blur remains.

In order to deal with such a problem, it is effective to set the control range of the vertical angle state from the pan / tilt operation switch to be smaller than the maximum vertical angle. For example, in a variable apex angle prism with a maximum apex angle of 5 °, if the control range from the pan / tilt operation method is set to 4 °, the residual blurring can be corrected at least 1 ° (5 ° -4 °) or less. Panning and tilting are performed without generating.

FIG. 10 shows an example of a flow chart of the microcomputer 45 when implementing the fifth embodiment.

The flow of FIG. 10 is the step 211 as shown between the steps 203 and 204 of the flow of the fourth embodiment.
1 to 216 are inserted, and the description of steps 201 to 203 and steps 204 to 208 will be omitted.
In the fifth embodiment, it is determined in step 211 whether or not blur correction is to be performed. When performing the shake correction, in step 212, | A _MAX | is set to 4 °. When the shake correction is not performed, | A _MAX | is set to 5 ° in step 213 and B is set to 0 in step 214. Next, in step 215, | A | and | A _MAX | are compared, and | A |
> | A _MAX |, in step 216 | A |
Replace with | = | A _MAX |, and then proceed to step 204. If not | A |> | A _MAX |
Go to 04. That is, when performing blur correction | A _MAX | = 4
That is, the range of the pan and tilt operations at that time is limited to between -4 ° and + 4 °.

(Sixth Embodiment) In the automatic pan / tilt device shown in the present embodiment, the greater the focal length is, the greater the effect is obtained as shown in FIG. The sixth embodiment of the present invention proposes to change the response operation of the angle change of the variable apex angle prism in accordance with the focal length in consideration of this point.

FIG. 11 shows a block diagram of the sixth embodiment. 11 having the same reference numerals as those in FIG. 4 have the same functions. In the figure, reference numeral 62 denotes an encoder for detecting the focal length, which is composed of, for example, a variable resistor for detecting the movement of the second group of the photographing lens.

The CPU 45 makes the following responses based on the focal length information. When the focal length is shorter than the specified focal length, it does not respond to the operation of the automatic pan / tilt device. The apex angle changing speed of the variable apex prism is controlled according to the focal length.

Since the above-described function has little effect when the focal length is short, it is operated only at the focal length where the effect can be obtained. For example, at a focal length where no effect is obtained, it may be possible to warn the viewfinder that the pan / tilt operation is inactive.

When the apex angle change speed of the variable apex prism is constant, the longer the focal length, the faster the movement of one point of the object in the viewfinder.

In consideration of this point, the longer the focal length is, the slower the apex angle changing speed is to achieve a natural pan and tilt.

FIG. 12 shows a flow for controlling the apex angle changing speed during the pan and tilt operations in the sixth embodiment.

When it is determined in step 302 that a pan or tilt operation has been performed, the focal length f is read in step 303, and the actuator moving speed v corresponding to f is determined in step 304.

In step 305, assuming that a method of shifting the apex angle displacement at predetermined time intervals is used for controlling the moving velocity of the actuator, for example, a cycle K for shifting the apex angle displacement is set according to the traveling velocity v. To decide.

In step 306, it is determined whether K = 0,
When K = 0 is not satisfied, the process proceeds to step 307 and K = K-1
And In this case, since the vertical angle displacement is not shifted, the vertical angle displacement A = A is set in step 308. K = 0
Is counted down in steps 306 to 308. Then, when K = 0 in step 306,
The process proceeds to step 307, and in this example, the vertical angle displacement A =
The vertical angle displacement is shifted to A + 1.

For example, when A is 1 = 0.1 °, K = 1se
If it is equivalent to c, the command by the pan / tilt operation has a moving speed of 0.1 ° / sec. If K is large, it will be slow, and if K is small, the apex angle will change quickly.
If the focal length is long, K is increased so that K is increased.
The arithmetic expression in is set.

[0075]

As described above, according to the present invention,
By using the correction means of various shake prevention devices, it is possible to perform shake correction and at the same time enable smooth panning shooting and tilting shooting with the camera position facing almost one direction,
This has a great effect on drawing.

Further, by reducing the range in which the correction means is driven to perform the panning and tilting operations, it is possible to achieve both good blur correction over the entire range.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a change in angle of view when a variable prism is driven.

FIG. 2 is an explanatory diagram showing a switch configuration.

FIG. 3 is an explanatory diagram showing a display in an electronic viewfinder.

FIG. 4 is a block diagram of the first embodiment.

FIG. 5 is a flowchart of the first embodiment.

FIG. 6 is a flowchart of the third embodiment.

FIG. 7 is an explanatory diagram showing changes in the apex angle state.

FIG. 8 is a block configuration diagram of a fourth embodiment.

FIG. 9 is a flowchart of a fourth embodiment.

FIG. 10 is a flowchart of the fifth embodiment.

FIG. 11 is a block diagram of a sixth embodiment.

FIG. 12 is a flowchart of the sixth embodiment.

FIG. 13 is an explanatory diagram showing a relationship between a focal length and a blur angle.

FIG. 14 is an explanatory diagram showing a configuration of a variable apex angle prism.

FIG. 15 is an explanatory view showing the operation of the variable apex angle prism.

FIG. 16 is a block diagram of a variable apex angle prism unit.

FIG. 17 is a block diagram of a shake prevention device having a variable apex angle prism.

Claims (5)

[Claims] 1. An optical device having a blur detecting means for detecting a blur and a blur correcting means for correcting an image blur in accordance with an output of the blur detecting means for sequentially moving a subject image in a photographing screen. An optical apparatus comprising: an operating means and a control means for controlling the driving of the blur correcting means in accordance with the operation content of the operating means and the output of the blur detecting means. 2. The optical apparatus according to claim 1, wherein the control unit controls the blur correction unit to be driven within a range smaller than the maximum correction range of the blur correction unit. 3. A focal length detecting means for detecting a focal length of a lens is provided, and the control means controls a driving speed of the blur correcting means in accordance with a detection result by the focal length detecting means. The optical device according to claim 1. 4. A focal length detecting means for detecting a focal length of a lens is provided, and when the focal length of the lens is shorter than a predetermined value, the control means prohibits driving of the blur correcting means. The optical device according to claim 1 or 2, which is characterized in that. 5. The optical apparatus according to claim 1, further comprising display means for displaying a correction range of the blur correction means in a viewfinder.