JPH08304866A - Bokeh warning camera - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to warn whether or not blurring is acceptable, regardless of the cause of the blurring and according to the size and format of the finished photo. [Configuration] Acceleration sensor 1 for detecting camera shake amount
2. Distance measuring unit 11 for detecting the defocus amount of the photographing lens
Based on the shake amount and / or the defocus amount, the blur amount on the film surface is obtained, the blur amount is compared with the blur allowable amount (S13), and a warning is given (S14). At this time, the blur allowable value can be set according to the photo size, whether panorama shooting or normal shooting, positive film or negative film, and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blur warning camera that warns that blur occurs on a film surface.

[0002]

2. Description of the Related Art Conventionally, as a camera of this type, for example,
It is known that a shake amount is detected, and when the shake amount becomes larger than a shake allowable amount set in advance based on a shutter speed and a focal length of a photographing lens, an alarm is issued by sound or display.

[0003]

However, the above-mentioned conventional camera tries to maintain the image quality more than necessary when the photo magnification is small, so that the operation of the camera becomes slow and unnecessary warnings are issued. There was a problem that it came out. In addition, even though I thought that the focus was a nice photo, in fact, there were times when it was blurred due to camera shake. This is not noticed in the service version, but it often appeared remarkably when it was expanded and printed in a cabinet or more.

A first object of the present invention is to provide a blur warning camera which warns whether or not a photograph produced is blurred regardless of the cause of the blur. A second object of the present invention is to provide a blur warning camera that warns whether or not blur is acceptable, depending on the size and format of the finished photo.

[0005]

In order to solve the above-mentioned problems, the invention of claim 1 provides a shake detecting section for detecting a shake amount of a camera, and a defocus amount detecting section for detecting a defocus amount of a photographing lens. In the shake warning camera provided with, based on the shake amount and / or the defocus amount, a blur amount calculation unit that obtains a blur amount on the film surface, and compares the blur amount with a blur allowable amount, The present invention is characterized by including a blur warning control unit that generates a blur warning signal and a warning unit that issues a warning based on the warning signal.

According to a second aspect of the present invention, in the blur alarm camera according to the first aspect, the blur allowable value is a photograph size,
The present invention is characterized in that a blur allowable amount setting unit that can be set according to at least one criterion of whether to perform panoramic shooting or normal shooting and whether to use positive film or negative film is provided.

[0007]

According to the present invention, the blur amount of a photograph in consideration of the shake amount and the defocus amount is calculated and compared with the blur allowable amount to issue an alarm. In addition, the allowable amount of blur can be set by the photo size (magnification) and the like.

[0008]

EXAMPLES Examples will be described below with reference to the drawings.
This will be described in more detail. FIG. 1 is a block diagram showing an embodiment of a camera capable of detecting shake according to the present invention, and FIG. 2 is an external perspective view showing the camera according to this embodiment. The camera of this embodiment has a camera body 1 as shown in FIG.
It is composed of a lens barrel 2 which can be attached to and detached from the camera body 1.

The control circuit 10 controls the photographing of the entire camera and, in accordance with the flow charts of FIGS.
This is a circuit for controlling the shake warning of the present embodiment, and CP
U, memory, etc. are included.

The distance measuring section 11 is a section for measuring the distance to the subject, and its output is connected to the control circuit 10. The distance measuring unit 11 employs a phase difference detection method, for example. The distance measuring unit 11 is also used as a shake detecting unit in addition to the distance measuring for AF.

FIG. 3 is a diagram for explaining the distance measuring unit (phase difference detection method) used in the camera of this embodiment. In the phase difference detection method, when the light flux from the taking lens 2a is divided into two with the optical axis L interposed, the light fluxes coincide with each other at the focus point, but the order of the light fluxes is changed before and after that. , An AF method that utilizes the occurrence of a shift. The detection element 11b detects the state of the two separated light fluxes near the focus. The dotted line shows the state in which the position (11a) equivalent to the film is in focus. Since the distance between the two images on the detection element 11b is constant (xo) when the subject is in focus, how long the image distance when the subject is out of focus is longer than that when the subject is in focus. The phase difference (dx) that is short is detected. The amount of focus shift from the position equivalent to the film at this time is called the defocus amount dz, and is calculated by the following equation. dz = C · F · dx (1) where C is a proportional constant and F is an F number. The detection element 11b is used by irradiating only the necessary luminous flux.

Returning to FIG. 1, the angular velocity sensor 12 is a sensor for detecting shake, and its output is connected to the control circuit 10. The shutter 13 is for controlling the exposure time on the film. Sequence motor 14
Is a motor for charging and driving the shutter 13, the mirror (not shown) and the like, and winding. The AF motor 15 is a motor that is arranged in the camera body 1 or the lens barrel 2 and drives the photographing lens 2a to move and focus.

The display section 16 is a section for displaying the exposure and the number of films, and the external display section 16 shown in FIG.
a and a display section (not shown) in the finder. In this embodiment, the external display unit 16a displays the size of a picture when the size of the picture is predetermined. The display in the viewfinder displays a shake warning.

The sound producing section 17 is a section for issuing a sound warning when the exposure is inappropriate or when the camera shake is large.

The main switch SW1 is a switch for turning on the main power source of the camera. Mode switch SW2
Is a switch for selecting a first mode in which a blur warning is given to the camera according to a predetermined initial value, and a second mode in which a blur warning is given according to a photograph size desired by the user. The main switch SW1 and the mode switch SW2 are operated by the slide switch 3 shown in FIG. The slide switch 3 is in a power-off state (main switch SW1
Is turned off) and the mark is turned on, the power is turned on.
State (main switch SW1 is ON). Also,
When the slide switch 3 is in the ON position, the mode switch SW2 is in the first mode, and when it is further slid to the right, the mode is switched to the second mode.

The release switch SW3 is a switch for starting the exposure sequence by fully pressing the release button 4 (see FIG. 2). The half-press switch SW4 is a switch that starts shooting preparation operations such as distance measurement and photometry by pressing the release button 4 halfway. Setting switch S
W5 is a switch for setting a photo size (or a corresponding magnification). The setting switch SW5 operates by pushing the push button switch 5 (see FIG. 2).

The lens control circuit 21 stores the focal length of the lens barrel 2, the diaphragm, the distance to the focal point, etc., and can communicate with the control circuit 10 on the camera body 1 side.

Next, the second mode for giving a warning of vibration according to the photograph size desired by the user will be described.
The second mode is based on a blur amount (hereinafter, referred to as a total blur amount VB) that is caused by both the focus blur amount due to the lack of focus and the blur amount due to camera shake.
Control the blur warning.

FIG. 4 is a diagram for explaining the out-of-focus amount. If the taking lens 2a has a focal length f and a lens aperture D, and the distance from the taking lens 2a to the subject is a and the distance to the in-focus position on the film surface side is b, the following equation is obtained. It holds. 1 / f = (1 / a) + (1 / b) (2) At this time, when the film is further away from b by Δz, the light that should originally be collected at one point is a circle of diameter δ. (This δ is referred to as the out-of-focus amount). δ = | (D / b) · Δz | (3) Further, the F number of the lens is as follows. f / D = F (4) Therefore, the equation (3) is as follows. δ = | [F / (f · b)] · Δz | = | (F / f) · [− (1 / a) + (1 / f)] · Δz | = | (F / f ² ) · [ − (F−a) / a] · Δz | (5) Therefore, if the above f, F, Δz, a (or b) is known,
The out-of-focus amount δ can be calculated.

5 and 6 are diagrams for explaining the blur amount. First, the image blur amount Δw on the film surface is
It is given by the following formula. Δw = (+ b + Δz) · θ (6) However, Δz is negative when the film surface is on the lens side with reference to b, and is positive when the film surface is opposite. Here, the blur angle θ is calculated by integrating the output value of the angular velocity sensor 12. The other reference numerals are the same as those in FIG. Substituting b = af / (af) obtained from the equation (2), Δw = [af / (af) + Δz] · θ (7) Therefore, the image blur amount Δw is a, f , Θ, Δz (or b,
θ, Δz). In addition, Δz << b, Δz << f,
Since Δz << a, Δz can be omitted.

When the angular velocity from the angular velocity sensor 12 is ω, the blur angle θ is given by the following equation. θ = ∫ωdt (8) Here, as shown in FIG. 6, the angular deviation of the camera is recorded with the passage of time from t = 0 (exposure start time) to t = Δt (exposure end time). To do. The maximum value and the minimum value θxmax of the angle deviation with respect to the x direction and the y direction,
θxmim, θymax, θymim are obtained. The image blur during exposure is VI = (b + Δz) [(θxmax−θxmim) ² + (θymax−θym im) ² ] ^1/2 (9)

Therefore, the total blur amount VB is calculated by the equation (5),
From (9), it can be obtained by VB = δ + VI (10).

Next, the operation of the camera according to this embodiment will be described. FIG. 7 is a flow chart for explaining the operation of the camera of this embodiment. The control circuit 10 determines whether or not the half-push switch SW4 is on (S1). When the half-push switch SW4 is on, the process proceeds to step 2, and when it is off, the process waits until there is an input. Next, the control circuit 10 performs photometry (S
2) The distance to the subject is measured, and the focus of the taking lens 2a is adjusted by the phase difference method (S3). Then, the display section (external display section and in-viewfinder display section) 16 displays the number of films, the exposure value, etc. (S4).

The control circuit 10 determines whether or not the mode switch SW2 is on (S5). If the mode switch SW2 is off, the process proceeds to step 6 (first mode), and if it is on, step 13 (first). 2 mode). In step 6,
It is determined whether VI is larger than VD, and if it is larger, the process proceeds to step 7. VI is the detected blur amount. Here, the blur amount is detected by the distance measuring unit 11 and the angular velocity sensor 12. VD is a threshold value for generating a blur warning. In step 7, a warning is issued. The warning is given by the display unit (external display unit and / or in-viewfinder display unit) 16. The warning may be given by the sounding unit 17 in addition to the display unit 16.

The control circuit 10 has a release switch SW3.
Is turned on (S8), and when it is turned on, the shutter is opened and closed to perform a series of shooting operations such as an exposure sequence (S9) for exposing the film and a winding charge (S10). Again, in step 11, it is judged whether or not the VI detected during the release is larger than VD, and if it is larger, the process proceeds to step 12 and a warning is given.

For example, in step 13, it is judged whether or not the allowable blur amount (VS) is larger than VB, and if it is larger, the process proceeds to step 14. Allowable blur amount (VS) obtained from the size (magnification) of the user's selected photograph,
The defocus amount detected by the distance measuring unit 11 is compared with the blur amount VB caused by both the shake amount detected by the acceleration sensor 12. The VB will be described later.

In step 14, when the blur amount VB is large, a shake warning is issued (same as S7 and S9).
S15 to S17 are the same as S8 to S10.

In step 18, the allowable blur amount VS obtained from the size at which the photograph selected by the camera user is viewed.
Is compared with the blur amount VB generated by the defocus amount and the shake amount during the release. The shake amount during release is the shake amount detected by the acceleration sensor 12 and the distance measuring unit 11
Calculated by the distance to the object detected by the camera and the focal length information of the photographing lens [Equation (7)] (S
Same as 11.). S19 is the same as S12.

FIG. 8 is a flow chart showing the photo size selection process. When the setting switch SW5 is further turned on while the mode switch SW2 is on, an interrupt is activated to switch the photographing state to a state in which the photograph size (or magnification) can be selected. In S21, what the selected photo size is is displayed. In S22,
It is determined whether the setting switch SW5 is on. If it is off, the process proceeds to S23, the interrupt is released, and if it is on, the process proceeds to S24. At S24, the half-press switch S
It is determined whether or not W4 is turned on, and each time it is turned on, the process proceeds to S25 and the size is switched. For size switching, i = 1 (service version or less), i = 2 (cabinet), and i = 3 (4 or more cuts) are cyclically switched. When the size is switched, the blurring allowable amount (VS) corresponding to the photo size is switched.

FIG. 9 is a diagram showing the allowable blur amount of the camera of this embodiment. When the photo size is small, the blurring allowance VS is large, and when the photo size is large,
The blurring allowable amount VS becomes smaller. When the detected blur amount exceeds a permissible value corresponding to each photo size (magnification), a warning is issued.

(Other Embodiments) FIGS. 10 and 11 are views for explaining another embodiment of the blur warning camera according to the present invention. In the embodiment of FIG. 10, the blurring allowable value is set depending on whether it is a positive film or a negative film. In the case of a positive film, the allowable blur amount VS is small, and in the case of a negative film, the allowable blur amount VS is large.

In the embodiment shown in FIG. 11, the blur allowable value is set depending on whether the panoramic shooting or the normal shooting is performed. In the case of panoramic photography, the blurring tolerance VS is small because the image is stretched greatly, and in the case of normal photography, the blurring tolerance VS is large.

The present invention is not limited to the embodiments described above, and various modifications and changes are possible, which are also included in the present invention. For example, in step 6 of FIG. 7, the output of the distance measuring unit 11 is not used for detecting the shake amount, and the acceleration sensor 1
When 2 is used, VI and VD can be set based on the focal length of the taking lens 2a and the distance information to the subject. Further, the shake amount by the distance measuring unit 11 and the shake amount by the acceleration sensor 12 may be constantly compared and calibrated with each other. In this case, the focal length of the taking lens 2a and distance measurement information to the subject are not particularly required.

For example, in step 14 of FIG. 7, the release cannot be performed when the blur amount is large.
If the release priority is taken into consideration, it is possible to proceed from S14 to S15 as if proceeding from S7 to S8. Further, depending on whether the user is prioritized release, it may be set either beforehand.

[0035]

As described in detail above, according to the present invention, the blur amount of a photograph is calculated in consideration of the shake amount and the defocus amount, and the alarm is made by comparing with the blur allowable amount. Good pictures can be obtained regardless of the cause of blur.
In addition, since the allowable amount of blur can be set according to the photo size (magnification) and the like, it is possible to give a necessary and sufficient warning, and unnecessary warning causes distraction or slows the camera operation. It's gone.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a camera capable of detecting shake according to the present invention.

FIG. 2 is an external perspective view showing a camera according to the present embodiment.

FIG. 3 is a diagram illustrating a distance measuring unit (phase difference detection method) used in the camera according to the present embodiment.

FIG. 4 is a diagram for explaining an out-of-focus amount.

FIG. 5 is a diagram for explaining a blur amount.

FIG. 6 is a diagram for explaining a blur amount.

FIG. 7 is a flow chart for explaining the operation of the camera of the present embodiment.

FIG. 8 is a flowchart showing a photo size selection process.

FIG. 9 is a diagram showing an allowable blur amount of the camera of the present embodiment.

FIG. 10 is a diagram for explaining another embodiment of the blur warning camera according to the present invention.

FIG. 11 is a diagram for explaining another embodiment of the blur warning camera according to the present invention.

[Explanation of symbols]

 1 Camera body 2 Lens barrel 2a Shooting lens 3 Slide switch 4 Release button 5 Push button switch 6 Dial switch 10 Control circuit 11 Distance measuring unit 12 Accelerometer 13 Shutter 14 Sequence motor 15 AF motor 16 Display unit 17 Sounding unit 21 Lens control Circuit SW1 Main switch SW2 Mode switch SW3 Release switch SW4 Half-press switch SW5 Setting switch

Claims (2)

[Claims] 1. A shake warning camera including a shake detecting unit for detecting a shake amount of a camera and a defocus amount detecting unit for detecting a defocus amount of a photographing lens, wherein the shake amount and / or the defocus amount Based on quantity
A blur amount calculating unit that obtains a blur amount on the film surface, a blur warning control unit that compares the blur amount with a blur allowable amount, and generates a blur warning signal, and a warning unit that issues a warning based on the warning signal. An out-of-focus warning camera characterized by having and. 2. The blur warning camera according to claim 1, wherein the blur allowable value can be set according to at least one criterion of a photo size, whether panorama shooting or normal shooting, and positive film or negative film. A blur warning camera, which is equipped with a simple blur tolerance setting unit.