JPH07199264A - Electronic still camera and electronic still camera system - Google Patents

Abstract

PURPOSE:To reduce photographing errors by outputting a warning signal in the case of deciding that at least a part of a luminous flux is not made incident on an imaging device. CONSTITUTION:This camera is provided with a decision means 21a deciding that at least a part of the luminous flux transmitted through a mounted photographing lens is not made incident on the imaging device, and a display unit 22 and a buzzer 23 which output the warning signal in the case the decision means 21a decides that at least a part of the luminous flux is not made incident on the imaging device. That is, in the case of mounting the photographing lens by which a part of subject light made incident on the reduction optical system of the electronic still camera from the photographing lens is not projected to the imaging device, various kinds of information are transmitted to a camera CPU 21 from a lens ROM 20, and the decision means 21a decides the information and gives a warning by displaying that the lens can not be used on the display unit 22 or sounding the buzzer 23. Thus, four corners of a video are prevented from being omitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic still camera and an electronic still camera system in which a subject light flux passing through a photographing lens is reduced and guided to an image pickup device.

[0002]

2. Description of the Related Art 2 using a 35 mm wide silver salt film
Single-lens reflex cameras that record images in a size of 4 mm × 36 mm have been popular. On the other hand, an electronic still camera that records video information on a magnetic medium, a semiconductor memory or the like instead of the silver salt film has been developed in recent years. In this electronic still camera, a subject is photographed by an image pickup device such as a CCD, and an analog signal from the CCD is signal-processed and recorded in a memory card. Since many interchangeable lenses that can be used in the above single-lens reflex camera are on the market, it is preferable that the interchangeable lens can also be used in electronic still cameras.

However, as described above, since the size of the exposed area of the silver salt film is larger than the subject light receiving area of the CCD image pickup device, when the interchangeable lens of the conventional single-lens reflex camera is used in the electronic still camera, Even if a wide-angle lens with a fairly large angle of view is used, some of the ambient light in the field is lost. Therefore, in this type of electronic still camera, a reduction optical system is provided behind the taking lens so that the entire area of the object scene is projected onto the CCD.

FIG. 11 is a view showing a conventionally known electronic still camera equipped with such a reduction optical system, in which a taking lens 1 is replaceably attached to a camera body 2.
Reference numeral 3 denotes a quick return mirror. Above the quick return mirror 3, a focusing screen 4 and a pentaprism 5 are sequentially arranged, and to the right of the pentaprism 5, a finder optical system 6 and an eyepiece 7 are provided. ing. Behind the quick return mirror 3, a shutter 8, a field lens 9 and a mirror 10 are arranged,
A mirror 11 for reflecting the reflected light of the mirror 10 in the direction of the taking lens 1 is arranged in parallel with the optical axis of the taking lens 1 on the reflected light path of the mirror 10. A relay lens 12, an optical low-pass filter 13, and an image sensor 14 are sequentially arranged on the reflected light path of the mirror 11. The field lens 9 and the relay lens 12 form a reduction optical system.

The operation of such a conventional electronic still camera will be described. The diaphragm lever 1a built in the photographing lens 1 engages with the diaphragm control member 2a of the camera body 2 to narrow down the diaphragm 1b to the set diaphragm value. The light flux condensed by the taking lens 1 passes through the diaphragm 1b, and the quick return mirror 3
It is reflected by and is focused on the focusing screen 4. The image formed on the focusing screen 4 is observed by the photographer 15 through the pentaprism 5, the finder optical system 6 and the eyepiece lens 7.

On the other hand, a part of the light flux diffused by the focusing screen 4 is incident on a photometric device (not shown), and when the photographer half-presses a release button (not shown), photometry is performed. When the photographer further presses the release button, the quick return mirror 3 retracts from the optical path and the shutter 8 opens. The light beam condensed by the taking lens 1 forms an image on the primary image forming surface 16,
After that, the image is reduced and re-imaged on the image sensor 14 by the action of the relay lens 12 through the field lens 9 and the mirrors 10 and 11. The optical low-pass filter 13 arranged in front of the image sensor 14 removes a predetermined spatial frequency component.

The optical image formed on the image pickup device 14 is converted into a charge signal and accumulated, and the accumulated signal charge is output as an electric signal and converted into a digital amount, which is not shown. It is recorded in the image memory or the like as image data by the control circuit.

The luminous flux incident on the relay lesbian 12 is f
Approximately 5.6 (diameter of relay lens / distance from relay lens to primary image plane = 5.6), and taking lens 1 has f
1.4 to f4 (shooting lens diameter / focal length = 1.4 to
Therefore, not all the light flux that has passed through the taking lens is incident on the relay lens.

[0009]

However, the conventional electronic still camera as described above has the following problems because it is configured to control the exposure amount by the diaphragm 1b of the taking lens 1. FIG. 12 is a view showing the taking lens 1 in a simplified manner by linearly developing the optical system of the camera of FIG.
Of the subject light that has passed through the diaphragm 1b, the field lens 9
The light flux incident on the periphery of the image is projected from the relay lens 12 onto the image sensor 14. As can be seen from FIG. 12, in order for the subject light incident on the periphery of the field lens 9 to be entirely projected from the relay lens 12 onto the image sensor 14, the incident angle θ of the subject light incident on the periphery of the field lens 9 is predetermined. Must be in the range.

Therefore, as shown in FIG. 13, when the taking lens 1A having a focal point longer than that in FIG. 12 is mounted and used by narrowing down, the incident angle θ of the subject light becomes large,
Ambient light in the field cannot enter the relay lens 12, and ambient light in the field is not projected on the image sensor 14. On the contrary, as shown in FIG. 14, the taking lens 1B having a focal point shorter than that in FIG.
When the lens is mounted and used by narrowing down, the incident angle θ of the subject light becomes small, and similarly, ambient light of the field is not projected on the image sensor 14.

However, since the subject light which does not enter the relay lens 12 and the image pickup element 14 enters the focusing screen 4 which is at a position conjugate with the primary image plane, a correct image without missing the four corners can be observed in the viewfinder. To be done. Therefore, the photographer may not notice that the four corners are missing until the video is reproduced and recorded.

It is an object of the present invention to provide an electronic still camera and an electronic still camera system which warn when a part of the subject light that has passed through the interchangeable lens does not enter the reduction optical system and the image pickup device.

[0013]

The present invention will be described with reference to FIGS. 1 and 11. According to the present invention, an image is formed on a primary image forming surface 16 through a taking lens 1 which is detachable from a camera body 2. It is applied to an electronic still camera having reduction optical systems 9 and 12 for reducing the aerial image and projecting it on the image sensor 14. The above-mentioned purpose is to determine the determining means 21a for determining that at least a part of the light flux transmitted through the attached photographing lens 1 does not enter the image sensor 14, and the determining means 21a.
The warning means 22 and 2 for outputting a warning signal when it is determined that at least a part of the light flux does not enter the image sensor 14.
This is achieved by including 3 and 3. As shown in FIG. 4, an aperture 12a on the side of the still camera that regulates the light amount of the subject light flux that passes through the reduction optical systems 9 and 12, and the taking lens 1
The aperture control unit 21 for controlling the exposure amount by opening the aperture 1b and adjusting the aperture 12a on the still camera side may be provided. Further, as shown in FIG. 9, the present invention has a photographing lens 32 having a first diaphragm 32b built therein, and a silver salt camera 30 for forming a subject image on a silver salt film by the photographing lens 32, and The present invention is applied to an electronic still camera system including an electronic still adapter 50 which is attached to a silver halide camera 30 and which reduces an object image guided through a taking lens 32 by reduction optical systems 52 and 55 and projects the image on an image sensor 57. . The above-described object is to calculate the exposure amount according to the second diaphragm 55a provided in the electronic still adapter 50 and the brightness of the subject, and when the electronic still adapter 50 is attached to the silver halide camera 30, This is achieved by opening the first aperture 32b and providing the aperture control means 35 for controlling the second aperture 55a to the set aperture value based on the calculated exposure amount.

[0014]

When the taking lens 1 is mounted such that part of the subject light incident on the reduction optical system 9 of the electronic still camera from the taking lens 1 is not projected on the image pickup device 14, the judging means 2 is operated.
1a judges it and warns it by the warning means 22 and 23.
When the electronic still adapter 50 is attached, the taking lens 32
The diaphragm 32a is opened, and the exposure amount is adjusted by the second diaphragm 55a built in the adapter 50. Therefore, since the light flux around the taking lens 32 can be used, even if the long focus lens or the short focus lens is used, the subject light at the four corners is not lost, and there are few mistakes, compared to the case where the aperture control is performed on the taking lens side. It is possible to shoot.

Although the present invention has been described with reference to the drawings of the embodiments in the section of means and actions for solving the above problems,
Therefore, the present invention is not limited to the embodiments.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. The electronic still camera of this embodiment is composed of the camera body and photographing lens shown in FIG. FIG. 1 shows a configuration example of a control system of an electronic still camera to which the present invention is applied. Reference numeral 20 denotes a lens ROM, which is provided in a photographing lens (interchangeable lens) of a conventionally used single-lens reflex camera. The interchangeable lens identification number, focal length information, open f-number information, and the like are stored in advance. 21
Is a camera CPU built in the camera body 2, and when the interchangeable lens 1 is attached to the camera body 2, various information is transmitted from the lens ROM 20 to the camera CPU 21 via a contact (not shown). Reference numeral 22 is a display device, and 23 is a buzzer, which indicates that the unusable lens, which will be described later, is mounted, or when the mounted zoom lens is set to the unusable focal length, the display device 22 displays unusable. Or buzzer 23
Used to ring or warn.

FIG. 2 is a flowchart showing a processing procedure executed by the camera CPU 21 to warn that an improper lens is attached. This program is executed when the taking lens is attached, and step S1
Then, the lens ROM 20 and the camera CPU 21 communicate with each other to receive lens-specific information from the lens ROM 20. In step S2, based on the received lens information, a previously stored data table is referred to, and it is determined whether or not the mounted lens is usable.

The data table is a table of information on whether the lens has four corners of the field or not when the camera body 2 shown in FIG. 11 is mounted. Is used to determine whether it is usable or unusable. If it is determined that the lens is unusable in step S3, an unusable lens warning is given in step S6. For example, a warning is displayed on the display 22 or a buzzer 23 is sounded to give a warning.

If it is determined in step S3 that the lens is not an unusable lens, it is determined in step S4 whether or not the lens can be used conditionally. When step S4 is denied, this program ends. In this case, the lens can be used. When step S4 is affirmed, the process proceeds to step S5, and it is determined whether the taking lens is in the unusable state or the usable state. The determinations in steps S4 and S5 are used when the taking lens is a zoom lens. The current focal length is detected from the focal length information included in the lens information received from the lens ROM, and the four corners of the object field at the focal length of the attached photographing lens are detected from the above-mentioned lens identification number and focal length information. It is determined whether or not there is a chip. When the focal length is in a state where the four corners of the object scene are lacking, an unusable warning is given in step S6. If it is determined that the focal length has no missing corners, the program will end without warning.

Whether or not the lens cannot be used can be determined from the lens identification number and the lens focal length as described above, based on the information in the above-mentioned table. In this case, information on the usable focal length range is also stored in advance in the data referred to by the lens identification number of the zoom lens. 3A to 3C show an example of read data when the data table is referred to by the identification number. When it cannot be used, the 7th bit is 0 as shown in (a), and when it can be used unconditionally, the 7th and 6th bits are 1 as shown in (b). When conditionally usable, the 7th bit is 1 and the 6th bit is 0 as shown in (c).
And the usable range is described in the 5th bit to the 0th bit. For example, in the case of a zoom lens of 28 mm to 105 mm, information indicating that the zoom lens of 50 mm to 80 mm can be used is described.

As described above, in the electronic still camera in which the interchangeable lens of the conventional single-lens reflex camera can be attached, is the attached interchangeable lens suitable for the reduction optical system of the electronic still camera? Determine whether or not
Since a warning is issued when it is not suitable, it is possible to avoid shooting in which the four corners of the field are cut off on the image sensor even though the observation image of the viewfinder accurately captures the object.

FIG. 4 is a view showing another embodiment in which a diaphragm is also incorporated in the still camera body. The same parts as those of the electronic still camera shown in FIG. 11 are designated by the same reference numerals, and the differences will be mainly described. The relay lens 12 is of a Gauss type, and a diaphragm 12a is provided inside the relay lens 12, and the diaphragm 12a and the shutter 8 are drive-controlled by a signal from the control circuit 21. A photometric signal from a photometric element that receives a part of the light beam scattered by the focusing screen 4 is input to the control circuit 21, and the control circuit 21 calculates an aperture value and shutter speed for performing proper exposure. A display control circuit 24 displays the aperture value and shutter speed calculated by the control circuit 21 on the display 22.
a and 22b. The display 22a is provided in the finder, and the display 22b is provided on the rear surface of the camera.

Reference numeral 1c is a contact provided on the mount surface of the taking lens 1, and 2b is a contact on the camera body 1 side to which the contact 1c is connected. The contact 2b is connected to the control circuit 21, and the mounting of the taking lens 1 is identified by the signal level of the contact 2b. Reference numeral 2c is a spring that constantly urges the aperture lever 1a of the taking lens 1 in the opening direction, and the aperture 1a of the taking lens 1 is always opened when the electronic still camera is mounted.

In the electronic still camera having such a structure,
The diaphragm 1b of the photographing lens 1 is always open, and the diaphragm 12a of the camera body 2 is drive-controlled to perform photographing. Therefore, as shown in FIG. 11, the diaphragm 1b of the taking lens 1 is
It is possible to use a lens on the long focus side and a lens on the short focus side as compared with the case of controlling the drive to control the exposure amount.

That is, FIG. 5 shows a lens having the same focal length as the taking lens 1A shown in FIG.
At the side diaphragm 1b, ambient light of the field lens 9 is incident on the relay lens 12 and the image sensor 14, and the four corners of the screen are not chipped as in the case of FIG. This is because the light incident on the periphery of the field lens 9 in FIG. 13 is the light flux at the center of the taking lens 1 that is narrowed down by the diaphragm 1b, whereas in FIG. 5, the light flux around the taking lens 1 can be used. Is.

The short focus side can be similarly explained. That is, FIG. 6 shows a lens having the same focal length as the taking lens 1B shown in FIG.
Then, the ambient light of the field lens 9 does not enter the relay lens 12 and the image pickup element 14, and the four corners of the screen are not chipped as in the case of FIG. This is because the light incident on the periphery of the field lens 9 in FIG. 14 is the light flux at the center of the taking lens 1 that is narrowed down by the diaphragm 1a, whereas in FIG. 6 the light flux around the taking lens 1 can be used. Is.

Therefore, according to the system in which the diaphragm 1b of the taking lens 1 is opened and the diaphragm 12a of the camera body 2 is narrowed down to control the exposure amount, the lenses 1A having a long focus and a short focus, as compared with the configuration of FIG. There is an advantage that 1B can be used. However, as shown in FIG. 7 and FIG. 8, in the lenses 1C and 1D on the long focal side and the short focal side, the peripheral light of the field lens 9 still does not enter the relay lens 12 and the image sensor 14. Therefore,
A warning is given by performing the determination processing of the unusable lens shown in FIG. Since the details are the same, they are omitted.

FIGS. 9 and 10 are views showing an example of a case where an electronic still adapter is attached to a silver halide camera to be used as an electronic still camera. In FIG. 9, 30 is a well-known silver salt camera, and 50 is an electronic still adapter that is mounted on the silver salt camera 30 and used as an electronic still camera. The silver salt camera 30 has a camera body 31 and a taking lens 32 mounted on the camera body 31.
Reference numeral 33 is a setting member for selecting the aperture priority mode and inputting a desired aperture, and 34 is a display for displaying the aperture value that has been set, and is arranged on the upper surface of the camera body 31. 35 is a control circuit built in the camera body 31,
The CPU 32 is configured of a CPU or the like, and controls the diaphragm 32a of the taking lens 32 so that the diaphragm value is input from the setting member 33, and displays the control diaphragm value on the display 34. 36 is a quick return mirror, 37 is a shutter, 38 is a focusing screen,
39 is a penta prism, 40 is an eyepiece lens, 41 is a contact, and a contact 55b of the electronic still adapter 50, which will be described later.
Connected with. The silver halide camera 30 also has a photometric device (not shown), and measures the brightness of the subject.

The electronic still adapter 50 includes an adapter main body 51, a field lens 52 on which the subject light from the silver halide camera 30 is incident, and mirrors 53 and 54 which are sequentially arranged behind the field lens 52. Like the electronic still camera shown in FIG. 1, the Gauss type diaphragm 55a is formed.
It has a relay lens 55 incorporating therein, an optical filter 56, and an image sensor 57. Also, the silver salt camera 3
Eyepiece 58 arranged behind the 0 eyepiece 40
Have. Since these optical systems have the same configurations as those of FIGS. 4 and 11, detailed description thereof will be omitted. 59 is C
A control circuit including a PU or the like controls the aperture 55a by calculating the aperture value from the exposure value calculated according to the brightness of the subject. The calculated aperture value is transferred to the control circuit 35 of the silver halide camera 30 via the contact 55b and the contact 41 of the silver salt camera 30.
And is displayed on the display 34.

FIG. 10 is a view showing a state in which the electronic still adapter 50 is attached to the silver halide camera 30, and the operation of this embodiment will be described below. When the electronic still adapter 50 is mounted, the contacts 41 and 55b are connected. When the power of the electronic still camera system is turned on in this state, the control circuit 59 or 35 discriminates that the electronic still adapter 50 is attached to the silver salt camera 30, and the first circuit on the silver salt camera 30 side.
The diaphragm 32a is opened. When the release button is half-pressed, the control circuit 59 or 35 calculates the exposure value so that the exposure amount suitable for the image sensor 57 is obtained based on the photometry result of the photometry element, and calculates the aperture value and the shutter speed.
These values are displayed on the display 34 of the silver halide camera 30.

On the other hand, when the silver salt camera 30 is used alone without mounting the electronic still adapter 50, when the power switch on the silver salt camera side is turned on, the control circuit 35 causes the electronic still adapter 50 to switch to the camera body. Identify that it is not attached to. When the release button is pressed halfway down, the exposure value is calculated based on the photometric result of the photometric element, and the aperture value and shutter speed are calculated. These values are displayed on the display 34 of the silver halide camera 30. When the release button is fully pressed, the control circuit 35 controls the aperture 32a to the control aperture value, and the shutter 37 is driven at the calculated shutter speed.

Therefore, in such a hybrid camera, when the electronic still adapter 50 is mounted, the diaphragm on the side of the photographing lens is opened, and the diaphragm on the adapter side controls the exposure amount. , 6, it is possible to use a lens on the longer focal point side or a lens on the shorter focal point side as compared with the case where the diaphragm is controlled on the photographing lens side.

[0033]

As described above, according to the present invention, a warning signal is output when a photographing lens in which a light flux of a part of a subject cannot be incident on the image pickup device is output, so that photographing mistakes can be reduced. . Also, when using the shooting lens used in the conventional silver salt camera as the shooting lens of the electronic still camera, the diaphragm on the shooting lens side is opened and the diaphragm on the still camera body side is controlled. A lens on the long focus side or a lens on the short focus side can be used as compared with the case of narrowing down the lens side.
In addition, the aperture on the electronic still adapter side is used when the electronic still adapter is attached to the silver salt camera, and the aperture on the taking lens side is used when the silver salt camera is used alone without the electronic still adapter attached. As a result, the operability is improved, and the long focus lens or the short focus lens can be used when used as an electronic still camera.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a control circuit of an electronic still camera according to the present invention.

FIG. 2 is a flowchart showing a lens determination process.

[FIG. 3] Lens usable data, conditional usable data,
It is a figure which shows unusable data.

FIG. 4 is an overall configuration diagram of an embodiment of an electronic still camera according to the present invention.

5 is a diagram illustrating a taking lens that can be used in the electronic still camera of FIG.

FIG. 6 is a diagram illustrating a taking lens that can be used in the electronic still camera of FIG.

FIG. 7 is a diagram illustrating a photographing lens that cannot be used in the electronic still camera in FIG.

FIG. 8 is a diagram illustrating a photographing lens that cannot be used in the electronic still camera of FIG.

FIG. 9 is a diagram separately showing the overall configuration of an embodiment of a hybrid camera.

FIG. 10 is a diagram showing an overall configuration of an embodiment of a hybrid camera.

FIG. 11 is an overall configuration diagram of an embodiment of a conventional electronic still camera.

12 is a diagram illustrating a taking lens that can be used in the electronic still camera of FIG.

FIG. 13 is a diagram illustrating a photographing lens that cannot be used in the electronic still camera of FIG.

FIG. 14 is a diagram illustrating a photographing lens that cannot be used in the electronic still camera in FIG.

[Explanation of symbols]

 1 Photographing lens 1a Aperture lever 1b Aperture 1c Contact point 2 Camera body 2a Aperture drive member 2b Contact point 3 Quick return mirror 4 Focus plate 9 Field lens 10, 11 Half mirror 12 Relay lens 12a Aperture 14 Image sensor 20 Lens ROM 21 Camera CPU 22 Display Device 23 Buzzer 30 Silver halide camera 32 Photographic lens 32a Aperture 33 Setting member 34 Display 35 Control circuit 50 Electronic still adapter 52 Field lens 55 Relay lens 55a Aperture 57 Image sensor 59 Control circuit

Claims (7)

[Claims] 1. An electronic still camera having a reduction optical system for reducing an aerial image formed on a primary image forming surface through a taking lens detachably attached to a camera body and projecting the reduced image on an image pickup device. Determining means for determining that at least a part of the light flux transmitted through the taking lens does not enter the image sensor; and a warning signal when the determining means determines that at least a part of the light flux does not enter the image sensor. An electronic still camera, comprising: an output warning unit. 2. The electronic still camera according to claim 1, wherein a light amount of a subject light flux passing through the reduction optical system is regulated,
An electronic still camera, comprising: an aperture provided in a still camera body; and an aperture control unit that opens the aperture on the photographing lens side and adjusts the aperture on the still camera side to control an exposure amount. . 3. A silver salt camera having a photographing lens having a built-in first diaphragm, wherein the photographing lens forms an image of an object on a silver salt film, and the photographing lens mounted on the silver salt camera. In an electronic still camera system including an electronic still adapter that reduces an object image guided via a reduction optical system and projects the image on an image sensor, a second aperture provided in the electronic still adapter and a brightness of the object are provided. When the electronic still adapter is attached to the silver salt camera, the first diaphragm is opened and the second diaphragm is set to a set diaphragm value based on the calculated exposure amount. An electronic still camera system, comprising: an aperture control unit for controlling. 4. The electronic still camera system according to claim 3, wherein a determination unit determines that at least a part of the light flux transmitted through the attached photographing lens does not enter the image sensor, and at least one of the determination unit An electronic still camera system, comprising: a warning unit that outputs a warning signal when it is determined that the light flux of a part does not enter the image sensor. 5. A silver salt camera having a taking lens having a built-in first diaphragm, wherein the taking lens forms an image of a subject on a silver salt film, and the taking lens mounted on the silver salt camera. In an electronic still camera system including an electronic still adapter that reduces an object image guided via a reduction optical system and projects the image onto an image sensor, the image capturing is performed when the electronic still adapter is connected according to the brightness of the object. Exposure calculation means for calculating a first exposure value suitable for the element, and for calculating a second exposure value suitable for the silver salt film when the electronic still adapter is not connected. Electronic still camera system 6. The electronic still camera system according to claim 5, wherein the second aperture provided in the electronic still adapter, and the first exposure value when the electronic still adapter is not attached. An electronic still device comprising: an aperture control unit that controls the first aperture and controls the second aperture based on the second exposure value when the electronic still adapter is attached. Camera system. 7. The electronic still camera system according to claim 5, wherein the display provided on the silver halide camera and the first exposure value are used when the electronic still adapter is not attached. The aperture value of the first aperture controlled by the display is displayed on the display, and when the electronic still adapter is attached, the aperture value of the second aperture controlled based on the second exposure value. An electronic still camera system, comprising: display control means for displaying a value on the display.