JPH04256287A - Image pickup device - Google Patents

Abstract

PURPOSE:To inform the occurrence of a fault in a variable apex angle prism (VAP) to the user. CONSTITUTION:A camera blur detection circuit 24 outputs a signal representing a blur of a camera in response to an output of a blur sensor 22 to a control circuit 28 and a fault discrimination circuit 26. An apex angle detection circuit 18 outputs a signal representing an apex angle to the control circuit 28 and the fault discrimination circuit 26 in response to the output of an apex angle sensor 16 sensing the apex angle of a VAP 10. The control circuit 28 changes the apex angle of the VAP 10 with an actuator drive circuit 14 and an actuator 12 so that the VAP 10 deflects an optical axis in a direction to cancel the blur of the camera. The fault discrimination circuit 26 discriminates it that the VAP 10 is defective under a prescribed condition such that the apex angle of the VAP 10 is unchanged for a prescribed period and the control circuit 28 blinks a light emitting element 32 by a luminance control switch 30 accordingly.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is applicable to video cameras and TVs.
It relates to photographic devices such as cameras.

0002

2. Description of the Related Art Video cameras have become smaller and lighter due to the practical use of solid-state imaging devices, and are rapidly becoming popular due to their high magnification and multifunctionality. Recently, exposure control and focus control have been automated, and there are fewer failures in shooting due to these. However, video cameras are usually used in a handheld position, and as they become lighter and more compact, the possibility of camera shake increases. It is no exaggeration to say that the screen is always shaky when hand-held, and the deterioration of image quality due to such screen shakyness and unpleasant situations such as video sickness are becoming a problem.

As means for suppressing or eliminating such screen blur, a configuration using a gyro mechanism or a configuration using an optical eccentric device such as a variable apex angle prism is known. The former uses a gyro mechanism to stabilize the lens barrel system regardless of camera shake.
The latter uses a variable apex angle prism to decenter the optical axis of the photographing optical system in a direction that offsets the shake of the photographing device body. For example, the variable apex angle prism has two prisms separated in the optical axis direction.
The structure is such that the periphery of two transparent plates is closed with a bellows, and the inside is filled with a liquid of a predetermined refractive index. By tilting the lens, the photographing optical axis is decentered.

0004

A conventional example using a gyro mechanism has the disadvantage that the camera body becomes large and heavy. In the conventional example using a variable apex angle prism, there is no need to make the lens barrel itself a movable structure, so it is possible to minimize the increase in size and weight of the camera body. There is no means to detect abnormal operation, and the user cannot take any measures when the variable apex prism malfunctions.

[0005] It is an object of the present invention to provide a photographing device that eliminates such inconveniences.

[0006]

[Means for Solving the Problems] The photographing device according to the present invention includes a shake detection means for detecting shake, and an optical axis that is driven according to the detection output of the shake detection means and decenters the optical axis of the photographing optical system. An imaging device equipped with an eccentricity means, comprising an abnormality detection means for detecting an abnormality in the optical axis eccentricity means, and a warning means for warning of the occurrence of an abnormality according to the detection result of the abnormality detection means. It is characterized by

[0007]

[Operation] With the above means, the user can immediately know the occurrence of an abnormality in the optical axis decentering means, and can take appropriate and prompt action.

[0008]

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

FIG. 1 shows a schematic block diagram of an embodiment of the present invention. 10 is a variable apex angle prism (VAP), 12 is an actuator (for example, a coil that generates an electromagnetic driving force) that changes the apex angle of the variable apex angle prism 10;
14 is a drive circuit for the actuator 12. 16 is an apex angle sensor that measures the apex angle of the variable apex angle prism 10;
is an apex angle detection circuit that outputs a signal indicating the apex angle of the variable apex angle prism 10 from the output of the apex angle sensor 16.

Reference numeral 20 denotes an imaging device consisting of a photographing optical system and a solid-state imaging device. Reference numeral 22 denotes a shake sensor that detects camera shake in the horizontal and vertical directions, and is fixed to the lens barrel of the photographing optical system of the imaging device 20. 24 is a camera shake detection circuit that detects the amount of camera shake from the output of the shake sensor 22; 26 is an abnormality determination circuit that determines whether there is an abnormality in the variable apex angle prism 10; 28 is a control circuit that controls the whole; 30 is the variable apex angle prism This is a light emission control switch that blinks the light emitting element 32 in accordance with a control signal from the control circuit 28 in the event of an abnormality.

34 is a camera process circuit that performs well-known camera signal processing on the photoelectric conversion signal from the image sensor of the imaging device 20 and outputs a standard format video signal, and 36 is an output terminal for the video signal of the captured image. .

The basic operation shown in FIG. 1 for blur correction will be explained. The camera shake detection circuit 24 outputs a signal indicating the amount of camera shake in the horizontal and vertical directions from the output of the shake sensor 22 to the control circuit 28 . Further, the apex angle detection circuit 18 outputs a signal indicating the current apex angle of the variable apex angle prism 10 to the control circuit 28 from the output of the apex angle sensor 16 . Control circuit 2
8 calculates the amount of change in the apex angle of the variable apex angle prism 10 necessary for blur correction, that is, the eccentricity of the photographing optical axis, from the outputs of the circuits 18 and 24, and uses the actuator drive circuit 14 and the actuator 12 to change the apex angle of the variable apex angle prism 10. Change the vertical angle of 10. As a result, a blur-free image signal is output from the imaging device 20, processed by the camera processing circuit 34, and
It is output from the output terminal 36.

Next, abnormality determination of the variable apex angle prism 10 will be explained. Although the details will be described later, the abnormality determination circuit 26
When detecting an abnormality in the variable apex angle prism 10, the control circuit 28 causes the light emitting element 32 to blink using the light emission control switch 30, thereby notifying the user of the abnormality in the variable apex angle prism 10. Thereby, the user can know that the variable apex angle prism 10 is abnormal, and can take appropriate measures such as cutting off the power supply.

FIGS. 2, 3, and 4 show the abnormality determination circuit 26.
2 shows a flowchart of abnormality determination in .

In FIG. 2, if the output θ of the apex angle detection circuit 18 remains constant for a predetermined period of time, it is determined that there is an abnormality. The detected value θ of the apex angle is constant because the camera body is not shaken, the variable apex angle prism 10 is not being driven correctly, or the variable apex angle prism 10 is locked in a state where it cannot be driven. In the first case, there is no need for blur correction using the variable apex angle prism 10, so there is no problem even if the power supply for blur correction is cut off.The latter two cases are clearly abnormal, so Warn that.

First, a loop variable k is initialized (S1), the output θk of the apex angle detection circuit 18 is read (S4), and its time differential value Ak (=dθk/dt) is determined (S5). Check whether the differential value Ak is substantially zero (S6
), if it is not zero, it is determined that there is no abnormality. (S7), and if it is substantially zero, increment the variable k (S8)
, k exceeds the predetermined number N (S2), it is determined that there is an abnormality (S3). That is, if the output θ of the apex angle detection circuit 18 remains constant for a predetermined period, it is determined that there is an abnormality.

In FIG. 3, the difference between the output B of the camera shake detection circuit 24 and the output θ of the apex angle detection circuit 18 is accumulated, and when the cumulative value reaches a certain abnormality, it is determined to be abnormal. Note that, of course, it is assumed that θ and B have been scaled to a common scale in advance. This takes advantage of the fact that when blur correction is functioning effectively, the integral value of the difference between B and θ always tends to converge to zero.

First, a loop variable k and a variable Ck for accumulating differences are initialized (S11). The output θk of the apex angle detection circuit 18 and the output Bk of the camera shake detection circuit 24 are read (S14), and the difference Dk (=θk−Bk) is calculated (
S15), and the difference Dk is accumulated by Ck (S16). Check whether the cumulative value Ck is greater than or equal to a predetermined threshold C (S17);
If it is equal to or greater than C, it is determined that it is equal to or greater than C (S18). If it is less than C, k is incremented (S19), and if k becomes a predetermined value N or more, that is, if it is not determined to be abnormal within a predetermined period (S12), it is determined that there is no abnormality (S13).

In FIG. 4, the integral value of the current I reaches a predetermined value E while the polarity of the drive current I of the actuator 12 remains unchanged.
If the condition exceeds the above, it is determined that there is an abnormality. If the polarity of the current changes, it can be said that the variable apex angle prism 10 is operating, and if the current continues to flow without changing the polarity, it can be said that the variable apex angle prism 10 is in operation. This is because there is a high possibility that it is in a locked state. Note that the drive current of the actuator 12 does not need to be directly measured using the output of the drive circuit 14;
It can be known from the control signal to 4.

First, the loop variable k, polarity variable S0, and current variable I0 are initialized (S21). Actuator 1
2 drive current Ik is read (S24), and its polarity is set to S.
Substitute it into k (S25). At the first time (i.e., k=1), the current value Ik is accumulated (S26), and from the second time onwards (S26), it is checked whether there is a change in the polarity Sk (
S27), if there is a change, it is determined that there is no abnormality (S23),
If there is no change, the current value Ik is accumulated (S28). If the cumulative value of the current is greater than or equal to the predetermined value E (S29), it is determined to be abnormal (S30), and if it is less than the predetermined value E (S29), k
is incremented (S31). If k becomes equal to or greater than the predetermined value N (S22), it is determined that there is no abnormality (S23).

The abnormality determinations shown in FIGS. 2, 3, and 4 may be used alone or in combination. Constant C, N
, E may be any appropriate value depending on the device configuration.

FIG. 5 shows a block diagram of a modified embodiment of the invention. The same components as in FIG. 1 are given the same reference numerals.

Although the light emitting element 32 may be placed anywhere as long as the user can easily notice its blinking, it is preferable to place it within the viewfinder, for example, as shown in FIG. In FIG. 5, 40 is a field of view of a viewfinder, and 42 is a display screen. In FIG. 5, the light emitting element 32 is arranged within the field of view 40 of the viewfinder 40 and outside the display screen 42. Instead of the light emitting element 32, a predetermined figure may be displayed inside or outside the display screen 42. Furthermore, the abnormality of the variable apex angle prism 10 may be warned by sound instead of light.

[0024]

As can be easily understood from the above explanation, according to the present invention, it is possible to notify the user of an abnormality in the optical axis decentering means for blur correction, and therefore, the abnormality in the optical axis decentering means can be detected. The power consumption associated with this can be avoided, and the user can take appropriate and prompt action.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of an embodiment of the present invention.

FIG. 2 is a first flowchart of abnormality determination for the variable apex angle prism 10 of this embodiment.

FIG. 3 is a second flowchart of abnormality determination for the variable apex angle prism 10 of this embodiment.

FIG. 4 is a third flowchart of abnormality determination for the variable apex angle prism 10 of this embodiment.

FIG. 5 is a layout diagram of an abnormality warning light emitting element 32.

[Explanation of symbols]

Claims (1)

[Claims] 1. A photographing device comprising a shake detection means for detecting shake, and an optical axis decentering means driven according to a detection output of the shake detection means and decentering an optical axis of a photographing optical system, comprising: An imaging device comprising: an abnormality detecting means for detecting an abnormality in the optical axis decentering means; and a warning means for warning of the occurrence of an abnormality according to a detection result of the abnormality detecting means.