JPH11326985A - Camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately set the condition of a diaphragm mechanism and a shutter mechanism in accordance with the luminance of subject light from a photographing lens group without being influenced by external light from a finder ocular part by making a liquid crystal shutter in a non-transmissive state in the midst of photometric operation by a photometry means. SOLUTION: While visually viewing a subject through a finder 18, a liquid crystal element 19 is made in a transmissive state from an LCD driver 21. When the camera is made in a remote control reception waiting state and a release signal is generated by turning on a shutter release switch 23 or a remote control switch 25, a CPU 22 measures the luminance of the subject detected by an AE sensor 20, generates data on a diaphragm and shutter speed in accordance with the measured luminance, and then drives the diaphragm mechanism 12 and the shutter mechanism 14 so as to photograph the subject. At such a time, in order to prevent the incident external light from being made incident on the sensor 20, the CPU 22 generates and supplies control data so that the liquid crystal shutter 19 may be made in the non-transmissive state from the driver 21.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has an eyepiece shutter in the optical path of a viewfinder optical system such as a single-lens reflex camera or a digital still camera having a TTL photometric function and capable of self-timer photography and remote control photography. About the camera.

[0002]

2. Description of the Related Art In recent years, a self-timer photographing (hereinafter, referred to as self-photographing) and a remote control photographing (hereinafter, referred to as remote control photographing) functions and a T-meter for measuring the brightness of a subject
Cameras having a TL photometric function have been put to practical use. This type of camera determines the composition of a subject viewed by a photographer from a viewfinder, and uses the result of photometry of the brightness of a subject image that reaches the viewfinder by the TTL photometry function to determine an aperture value or an exposure value of the camera. After setting the shutter speed, the photographing using the shutter release switch and the photographing using the self-photographing and remote control photographing functions are performed.

[0003] At the time of setting the image quality of the subject image or photometry, since the photographer is looking into the viewfinder, the incidence of external light from the viewfinder eyepiece is negligible. However, at the time of the self-photographing or the remote control photographing, since the photographer moves away from the eyepiece of the viewfinder, external light enters and reaches the TTL photometric function, and the photometric result changes, resulting in an error in the photometric value of the subject to be captured. Occurs.

For this reason, there is a camera provided with an eyepiece shutter for shielding external light incident from the eyepiece of the finder during self-photographing or remote control photographing.

The specific structure and configuration of the eyepiece shutter are disclosed in Japanese Patent Application Laid-Open Nos.
-43884.

In the eyepiece shutters disclosed in the above publications, a light-blocking member provided on an eyepiece of a viewfinder is formed so as to be driven by a spring member or an arm member. In this case, the light shielding member covers the eyepiece of the finder and shields external light.

[0007]

In the conventional eyepiece shutters disclosed in the above publications, when the photographer forgets to operate the eyepiece shutter, the external light incident from the finder is also measured, and the exposure is measured. Error occurs. In addition, it is devised that the self-shot or remote control shooting cannot be performed unless the external light incident on the finder is shielded by operating the eyepiece shutter. In addition, shooting becomes impossible, and it is necessary to mistake the camera for a malfunction or to approach the camera again to operate the eyepiece shutter, which causes inconvenience. Furthermore, the conventional eyepiece shutter has a mechanical structure, and the light-shielding member is retracted and driven in conjunction with a manual operation.
There were problems such as an increase in the size of the viewfinder.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a camera having an eyepiece shutter that automatically drives an eyepiece shutter in response to a photographer's photographing operation and has a small finder.

[0009]

According to a first aspect of the present invention, there is provided a camera, comprising: a photometer for measuring the brightness of an object; and an external light, which is disposed in an optical path of a finder optical system and which enters from a finder eyepiece, is transmitted to the photometer. A liquid crystal shutter capable of changing a state between a non-transmissive state in which light is blocked so as to prevent the light from arriving and a transparent state in which a subject image can be viewed from an eyepiece, and the liquid crystal shutter during a photometric operation by the photometric means. And a control unit for setting a non-transmission state.

According to a second aspect of the present invention, there is provided a camera which is arranged in a light path of a finder optical system and measures external light entering from a finder eyepiece to reach the light measuring means. Non-transmissive state to shield,
A liquid crystal shutter capable of changing a state to a transmissive state in which a subject image can be viewed from an eyepiece, a determining unit for determining whether a photometric value of a photometric result by the photometric unit is smaller than a predetermined value, and the determining unit As a result, when it is determined that the photometric value is smaller than the predetermined value, the liquid crystal shutter is set to a non-transmissive state, and control means for performing photometry again by the photometric means is provided.

According to a third aspect of the present invention, there is provided a camera which is arranged in a light path of a finder optical system and measures external light entering from a finder eyepiece to reach the light measuring means. Non-transmissive state to shield,
A liquid crystal shutter capable of changing the state to a transparent state in which the subject image can be viewed from the eyepiece, a mode setting means for setting the self-photographing mode or the remote control photographing mode, and the self-photographing mode or the remote control photographing mode; In this case, there is provided a liquid crystal control unit for setting the liquid crystal shutter to a non-transmission state at least during a photometric operation by the photometric unit.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of an embodiment of a camera having an eyepiece shutter according to the present invention.

Reference numeral 11 in the drawing denotes a photographing lens group composed of various lenses for taking in subject light, and an aperture mechanism 12 is arranged in the photographing lens group 11. A reflecting mirror 13 is provided on the optical axis of the subject light captured by the photographing lens group 11, and guides the subject light to a film or a finder described later. The reflecting mirror 13 is arranged obliquely with respect to the optical axis of the subject light, and the upper end is fixed by a rotating shaft (not shown), and is rotated upward in the figure. Behind the reflecting mirror 13, a film 15 is disposed via a shutter mechanism 14. The shutter mechanism 14 blocks the subject light reaching the film 15 during a non-photographing operation in which the photographer does not perform a photographing operation, and slides during the photographing operation to cause the subject light to enter the film 15. It is. That is, by the photographing operation of the photographer, the reflecting mirror 13 rotates to the position shown by the dotted line in the figure, and the shutter mechanism 14 slides to make the subject light reach the film 15. On the other hand, during a non-photographing operation, the reflecting mirror 13 is arranged at a position shown by a solid line in the figure, and reflects the subject light taken in by the photographing lens group 11 upward in the figure. The subject light reflected by the reflecting mirror 13 enters a pentaprism 17 via a focusing plate 16 on which a subject image is once formed. The pentaprism 17 has a plurality of reflecting surfaces, changes the optical axis of the subject light, and emits the light to the finner 18 from the exit side. The finder 18 includes a lens for converging subject light from the pentaprism 17, an eyepiece 27, and the like. Inside the eyepiece 27 of the finder 18,
A liquid crystal shutter 19 is provided. An automatic exposure sensor (hereinafter, referred to as an AE sensor) 20 that emits light at an angle different from that of the subject light emitted to the finder 18 and measures the luminance of the subject light is disposed on the emission light side of the pentaprism 17. ing.

The liquid crystal shutter 19 is formed of a known TN (twisted nematic) liquid crystal plate, a GH (guest / host type) liquid crystal plate, a polymer liquid crystal plate, or the like. The TN type liquid crystal plate utilizes the optical rotatory power, and is arranged such that the polarization axes are perpendicular to each other.
A liquid crystal element is sandwiched between two polarizing plates, and light incident from one of the polarizing plates is emitted along the polarization axis of the polarizing plate to the liquid crystal element, and the liquid crystal element is in a non-voltage state. In some cases, the liquid crystal molecules are twisted and aligned by 90 degrees, and the light incident on the liquid crystal element rotates 90 degrees. The light rotated by the liquid crystal element coincides with the deflection axis of the other polarizing plate, and the light is transmitted. On the other hand, when a voltage is applied to the liquid crystal element, the liquid crystal molecules of the liquid crystal element change in a certain direction, and the light passes through the polarizing plate and the liquid crystal element. That is, the liquid crystal element can switch between a light transmitting state and a light non-transmitting state depending on whether or not voltage is supplied to the liquid crystal element, and is a so-called electric shutter.

The liquid crystal shutter 19 is connected to a liquid crystal driver circuit (hereinafter, referred to as an LCD driver) 21 for supplying a voltage for transmitting or not transmitting light. A microcomputer (hereinafter referred to as a CPU) 22 is connected to the LCD driver 21.
A shutter release switch 23, a self-timer switch 24, a remote control switch 25, and a liquid crystal switch 26 are connected to the switch 22. When each of the switches 23 to 26 is turned on, the CPU 22 performs an operation mode process in accordance with the turned on switch, and the LCD driver 21 sends the liquid crystal element 1
9 is controlled to be in a transmission state or a non-transmission state.

The AE sensor 20 detects the luminance of the subject light incident through the photographing lens group 11, the reflecting mirror 13, and the pentaprism 17, and takes in the detected luminance amount into the CPU 22 so as to be appropriate. In order to allow the object light to enter the film 15, a control signal for controlling the aperture ratio of the aperture function 12 and the aperture time of the shutter 14 is generated, and the aperture function 12 and the shutter 1 (not shown) are generated.
4 is performed.

In the camera having such a configuration, when the subject is photographed based on the subject light projected on the viewfinder 18, while the subject is being viewed with the viewfinder 18, the LCD driver 21 outputs the liquid crystal. The element 19 is controlled to be in a transmission state. Next, when the shutter release switch 23 is turned on or the remote control switch 25 is turned on, the camera enters a remote control reception waiting state, and a release signal is generated by the remote control (a remote control signal receiving circuit is not shown). The CPU 22
Measures the brightness of the subject detected by the AE sensor 20, generates aperture and shutter speed data corresponding to the brightness, and drives the aperture mechanism 12 and the shutter mechanism 14 to photograph the subject. At this time, the external light incident on the AE sensor 20 from the eyepiece side of the finder 18 is
In order to prevent the AE sensor 20 from being incident on the AE sensor 20 via the pentaprism 17, the CPU 22 generates and supplies control data from the LCD driver 21 so that the liquid crystal shutter 19 is in a non-transmission state.

That is, the liquid crystal shutter 19 is in a transmissive state in order to project an object incident from the photographing lens group 11 onto the finder 18 when not photographing, and from the eyepiece side of the finder 18 when photographing. By setting the AE sensor 20 in a non-transmission state in order to block incident external light, the brightness measured by the AE sensor 20 becomes only a correct value of the subject to be photographed, Shooting at the shutter speed becomes possible.

A liquid crystal shutter 19 is arranged only inside the eyepiece of the finder 18, and an LCD driver 21 and a CPU 22 for driving the liquid crystal shutter 19 can be arranged in the camera body. It is possible to provide an eyepiece shutter that has a simpler structure and a smaller size than the eyepiece shutter, and that does not require a complicated mechanical drive mechanism, and that does not cause deterioration or deviation of the drive mechanism due to long-term use. became.

The liquid crystal shutter switch 26 is
This is a manual changeover switch provided to enable the liquid crystal shutter 19 to be operated manually in a transparent state or a non-transparent state regardless of the operation of the release switch 23, the self switch 24, and the remote control switch 25. By turning on / off the liquid crystal shutter switch 26, the CPU 22 sends the LCD driver 21
The transmission or non-transmission of the liquid crystal shutter 19 is controlled.

Next, the processing operation of the CPU 22 will be described with reference to FIGS.

FIG. 2 shows a processing operation when the shutter release switch 23 is turned on.

The photographer turns on the shutter release switch 23 while checking the subject projected from the eyepiece of the finder 18 onto the finder. Step S1
It is determined whether or not the release switch 23 has been turned on. If it is confirmed that the release switch 23 has been turned on, the focus lens (not shown) of the photographing lens group 11 is moved along the optical axis in step S2. Automatic focus adjustment (hereinafter, A
F). When the AF in step S2 is completed, control data for making the liquid crystal shutter 19 non-transmissive is generated in step S3, and the liquid crystal shutter 19 is made non-transmissive via the LCD driver 21. Next, in step S4, the luminance of subject light from only the photographing lens group 11 incident on the AE sensor 20 is measured, and aperture and shutter speed data are generated. Based on the aperture and shutter speed data generated in step S4,
When the drive control conditions for the aperture mechanism 12 and the shutter mechanism 14 are set, the set conditions are maintained, and step S5 is performed.
To set the liquid crystal shutter 19 in the transmissive state, and step S6
Exposure is performed according to the aperture and shutter speed setting conditions set in step S4. When the exposure in step S6 is completed, in step S7, a film winding drive unit (not shown) for winding the film is drive-controlled.

It should be noted that, after the AE in step S4, the processing procedure of the liquid crystal shutter transmission in step S5 and the exposure procedure in step S6 are exchanged.
It is also possible to perform the exposure of step S6, and after the exposure of step S6 is completed, set the liquid crystal shutter of step S5 to the transmission state.

That is, at the time of the photographing operation in which the release switch 23 is turned on, at least during the measurement of the luminance of the subject light by the AE sensor 20, the liquid crystal shutter 19 is turned on.
Is blocked, external light incident from the eyepiece of the finder 18 is shielded, and the brightness of only the subject is measured by the AE sensor 20 and photographing can be performed under the set conditions.

When the release switch 23 is operated while the subject is being viewed from the eyepiece of the viewfinder 18, the period during the AE measurement in step S4 is as follows.
Although the subject cannot be seen, this AE measurement period is instantaneous and does not give the photographer any sense of discomfort. Further, even if the steps S5 and S6 are interchanged, the A
The addition period of the E measurement period and the shutter speed is a period in which the photographer cannot visually recognize the photographer with the finder 18, but the setting of the long shutter speed that gives the photographer a sense of discomfort is almost negligible and is negligible. If the brightness of the subject is extremely low, it is possible to eliminate the shooting mode in which the shutter speed is extremely long by adding an automatic flash function.

FIG. 3 shows another embodiment. When the brightness of a subject measured by the AE sensor 20 in a state where the liquid crystal shutter 19 is transmitted through the liquid crystal shutter 19 is equal to or less than a predetermined value, the finder 18 is closed. When external light is incident from the eye, it is determined that the influence on the measured luminance is large, and the liquid crystal shutter 1 is determined.
9 is set to a non-transmissive state to accurately measure the luminance of the subject. Steps S11 and S12 are the same as steps S1 and S2. In step S13, AE measurement of the subject is performed, and the measured value is compared with a predetermined luminance value in step S14. This step S1
As a result of the comparison in step 4, when the luminance value is larger than the predetermined luminance value,
In step S18, exposure is performed under conditions such as the aperture and shutter speed based on the luminance value measured in step S13. If the luminance value is equal to or smaller than the predetermined luminance value, the liquid crystal shutter 19 is not transmitted through step S15. The state is set, and the AE measurement is performed again in step S16. At the time of the AE re-measurement in step S16, since the liquid crystal shutter 19 is in the non-transmission state, only the brightness of the subject can be measured. Based on the result measured in step S16, the conditions of the aperture and the shutter speed are set. With the set conditions maintained, the liquid crystal shutter 19 is made transparent in step S17. S1
Exposure is performed under conditions such as the aperture and shutter speed set as a result of the AE measurement of No. 6. When the exposure in step S18 is completed, the film 15 is wound up in step S19.

It should be noted that step S17 and step S1
Needless to say, the processing procedure of 8 can also be exchanged.

That is, at the time of AE measurement in step S13,
The luminance value of the subject light and the external light from the eyepiece of the finder 18 are measured and compared with the predetermined luminance value.
As a result of comparison with the predetermined luminance value, when the luminance value measured by AE is larger than the predetermined luminance value, the luminance value of the subject light itself is large, and external light incident from the eyepiece of the finder can be ignored. Therefore, exposure can be performed in step S18. However, if the brightness value compared in step S14 is equal to or less than the predetermined brightness value, it means that the brightness value of the subject light itself is small, and the subject light having the small brightness value is incident from the eyepiece of the finder 18. In this case, when external light is added and measured, a correct luminance value of the subject light is not measured, and erroneous conditions such as an aperture and a shutter speed are set, so that satisfactory photographing cannot be performed. For this reason,
In step S15, the liquid crystal shutter 19 is controlled to the non-transmissive state. In step S16, the luminance value of only the subject is measured again. While maintaining the aperture and shutter speed based on the remeasurement result, the liquid crystal shutter 19 is controlled in step S17. Is set in a transmission state, and exposure is performed in step S18, and step S19 is performed.
To wind up the film.

FIG. 4 shows still another embodiment, and shows a processing procedure when either the self switch 24 or the remote control switch 25 is operated.

In step S21, when the release switch 23 is directly operated or the remote control switch 25 is operated, the camera enters a remote control reception waiting state, and when a remote control release signal is received, the AF is performed in step S22.
An operation is performed. Next, in step S23, it is determined whether the operation in step S21 is the operation of the self-switch 24 or the remote control switch 25. That is,
When the self switch 24 is operated, the CPU 2
2 maintains the self-photographing mode, and when the remote control switch 25 is operated, the CPU 22 maintains the remote-control photographing mode. For this purpose, it is determined in step S23 whether the mode is the self or remote control shooting mode. If the release switch 23 is operated in a mode that does not correspond to any of them, the AE measurement is performed in step S29, and the exposure is performed in step S27. Transition. If it is confirmed that the mode is the self or remote control photographing mode, the liquid crystal shutter 19 is set to the non-transmission state in step S24, the AE is measured in step S25, the liquid crystal shutter 19 is set to the transmission state in step S26, and the exposure is performed in step S27. In step S28, the film is wound up.

That is, the liquid crystal shutter 19 is set in the non-transmissive state only during the self-photographing and the remote control photographing, and the AE
This eliminates erroneous measurement of the luminance of the subject due to light incident from the eyepiece side of the finder 18 during measurement. It goes without saying that steps S26 and S27 can be interchanged.

As described above, according to the present invention, the liquid crystal element is used for the eyepiece shutter built in the viewfinder, and the liquid crystal element is automatically controlled to the transmission state or the non-transmission state according to the photographing mode, and the AE is controlled. Shields external light incident from the viewfinder eyepiece at the time of measurement so that only the brightness of the subject is A
E can be measured.

[Appendix] According to the above-described embodiment of the present invention, an invention having the following configuration can be obtained.
That is, (Supplementary Note 1) In a camera including a liquid crystal shutter arranged in the viewfinder optical system and a photometric sensor arranged in the viewfinder optical system, the liquid crystal shutter does not block a light beam incident on the photometric sensor. A camera, which is arranged in a camera.

(Supplementary Note 2) A liquid crystal shutter arranged in the finder optics, a photometric unit for measuring the luminance of the subject,
A control unit for setting the liquid crystal shutter to a non-transmission state during the photometry by the photometry unit.

(Supplementary Note 3) A liquid crystal shutter arranged in the finder optics, a photometric unit for measuring the luminance of the subject,
When the photometric value of the photometric unit is smaller than a predetermined value, a control unit that sets the liquid crystal shutter to a non-transmission state and performs photometry again.

(Supplementary Note 4) A liquid crystal shutter arranged in the viewfinder optics, a photometric unit for measuring the luminance of the subject,
When set to self mode or remote control mode, at least during the photometric operation by the photometric means,
A camera, wherein the liquid crystal shutter is set to a non-transmission state.

(Supplementary Note 5) In Supplementary notes 1, 2, 3, and 4,
The liquid crystal shutter is a polymer dispersed liquid crystal.

[0039]

According to the present invention, when the photographer operates the shutter release switch or receives a remote control release signal while the camera is in the remote control reception waiting state, or the brightness information of the subject, without confirming the operation state of the eyepiece shutter. According to the, by automatically controlling the liquid crystal shutter built in the finder to the transmission state or the non-transmission state, the external light incident from the eyepiece of the finder is shielded,
By performing photometry, it is possible to set appropriate conditions of an aperture mechanism and a shutter mechanism in accordance with the luminance of subject light from the photographing lens group according to luminance information, and a liquid crystal shutter is used as the eyepiece shutter. Accordingly, there is an effect that the finder can be formed in a small size.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a camera having an eyepiece shutter according to the present invention.

FIG. 2 is a flowchart illustrating the operation of the present invention.

FIG. 3 is a flowchart illustrating the operation of another embodiment of the present invention.

FIG. 4 is a flowchart illustrating the operation of another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 photographing lens group 12 diaphragm mechanism 13 reflecting mirror 14 shutter mechanism 15 film 16 focusing screen 17 pentaprism 18 finder 19 liquid crystal shutter 20 AE sensor 21 LCD driver 22 CPU 23 for shutter Release switch 24 ... Self-timer switch 25 ... Remote control switch 26 ... Liquid crystal shutter switch 27 ... Eyepiece

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[Procedure amendment]

[Submission date] May 15, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0003

[Correction method] Change

[Correction contents]

At the time of composition setting and photometry of the subject image, since the photographer is looking into the viewfinder, the incidence of external light from the viewfinder eyepiece is negligible. However, at the time of the self-photographing or the remote control photographing, since the photographer moves away from the eyepiece of the viewfinder, external light enters and reaches the TTL photometric function, and the photometric result changes, resulting in an error in the photometric value of the subject to be captured. Occurs.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction contents]

[0039]

According to the present invention, when the photographer operates the shutter release switch or receives a remote control release signal while the camera is in the remote control reception waiting state, or the brightness information of the subject, without confirming the operation state of the eyepiece shutter. According to the, by automatically controlling the liquid crystal shutter built in the finder to the transmission state or the non-transmission state, the external light incident from the eyepiece of the finder is shielded,
By performing photometry, external light from the viewfinder eyepiece
It is possible to appropriately set the conditions of the aperture mechanism and the shutter mechanism in accordance with the brightness of the subject light from the photographing lens group without being affected, and the use of a liquid crystal shutter as the eyepiece shutter makes the finder compact. This has the effect of being able to be formed in

Claims (3)

[Claims] 1. A light measuring means for measuring the brightness of a subject, and a non-transmissive state arranged in a light path of a finder optical system to block external light incident from a finder eyepiece from reaching the light measuring means. A liquid crystal shutter capable of changing a state to a transmission state in which a subject image can be viewed from an eyepiece, and a control unit for setting the liquid crystal shutter to a non-transmission state during a photometry operation by the photometry unit. A camera characterized in that: 2. A photometric means for measuring the brightness of a subject, and a non-transmissive state which is arranged in a finder optical system optical path and which shields external light entering from a finder eyepiece from reaching the photometric means. A liquid crystal shutter capable of changing a state to a transmission state in which a subject image can be viewed from an eyepiece; a determination unit configured to determine whether a photometry value of a photometry result by the photometry unit is smaller than a predetermined value; When the result of the determination means determines that the photometric value is smaller than the predetermined value, the control means controls the liquid crystal shutter to be in a non-transmissive state and performs photometry again by the photometric means. A camera characterized by the following. 3. A photometric means for measuring the brightness of a subject, and a non-transmissive state which is disposed in a finder optical system optical path and shields external light incident from a finder eyepiece to prevent the light from reaching the photometric means. A liquid crystal shutter capable of changing a state to a transparent state in which a subject image can be viewed from an eyepiece; a mode setting unit for setting a self-photographing mode or a remote-controlling photographing mode; And a liquid crystal control unit for setting the liquid crystal shutter to a non-transmission state at least during a photometric operation by the photometric unit.