JPH0564067A - Camera - Google Patents

Abstract

PURPOSE:To obtain a video without black paint-out and white flying as the instantanity of recording (photographing) is kept by recording plural still pictures by successively varying a photometric system. CONSTITUTION:The output of an image pickup element becomes into a level directly proportional to a light quantity unless it is particularly added compensation or it is saturated. An amplifier 135 amplifies the value, a gate circuit 136 permits only a signal in an objective photometric range to pass and a peak hold circuit 137 detects the peak value of the passed signal to input it to a microcomputer 119. Then, some photometric system such as a center important point photometric system, a whole screen average photometric system and a background important point photometric system are selected to photograph the plural still picture with a diaphragm value proper to respective systems and to record them in a tape 134. A still picture can successively be photographed in a similar way changing any factor which can be changed with the photometric system such as the accumulating time, etc., of the image pickup element 106.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera capable of recording a plurality of still images by changing the photometric method.

[0002]

2. Description of the Related Art In recent years, in the field of magnetic recording, the demand for high-density recording has increased, and a video tape recorder (V
Also in (TR), the tape running speed has been reduced to achieve higher density magnetic recording.

When the running speed of the tape decreases, for example, when an audio signal is recorded by using a fixed head, the relative speed cannot be made large and the reproduced sound quality deteriorates. As one means for solving this, there is a method in which the length of the track operated by the rotary head is made longer than in the conventional case and the time-axis-compressed audio signal is sequentially recorded in the extended portion. Specifically, in the rotary 2-head helical scan type VTR, the magnetic tape was wound around the rotating cylinder by 180 degrees or more in the past, but in this method, the rotating tape is wound by (180 + θ) degrees or more, and extra winding is performed. This is a method of recording an audio signal which has been PCM-compressed and compressed on the time axis in the part of θ ″.

FIG. 6 is a diagram showing a tape traveling system of such a VTR, and FIG. 7 is a diagram showing recording tracks on a magnetic tape. In FIG. 6, 1 is a magnetic tape, 2 is a rotating cylinder,
Reference numerals 3 and 4 are heads attached to the cylinder 2, 5 is a video signal recording area portion of a track formed on the tape 1, and 6 is a PCM audio signal recording area portion. The video area 5 is traced by the heads 3 and 4 by 180 degrees of the rotary cylinder 2, and 6 is the rotary cylinder 2.
Is traced in θ minutes. 7 is the running direction of the tape 1, 8
Is the direction of rotation of the cylinder 2.

As described above, as an example of applying the method of recording a digital signal in another area while recording a video signal, it has been proposed to record a still image in the digital signal recording area as a digital signal. There is. If the image is a still image, it is possible to record all the information on the magnetic tape by scanning the PCM area a plurality of times. According to this method, not only can a still image be captured using the same recording medium as the same image capturing device as that for the moving image capture, but also the tape running in the conventional VTR is stopped and the video signal of the same track is reproduced. It is possible to obtain a high-quality still image from a still image.

[0006]

(1) In shooting a moving image, even if the result of photometry is unsuitable for a certain period during shooting and the function of adjusting the light amount such as the aperture and the exposure time is not desirable, It is possible to correct the state of the light amount adjusting function such as the diaphragm by changing the commonly used backlight compensation device and the angle of view, and even if such a compensation is applied, the viewer does not feel uncomfortable. Although it is small, once a still image is shot with an inappropriate light amount adjustment function, it is difficult to correct it during playback as well as during shooting.

(2) In the light quantity adjustment control used for a moving image, generally, the information of the output result is controlled by the diaphragm drive circuit so that the image signal level output from the image sensor and the signal processing circuit at the subsequent stage becomes appropriate. Since it is to be fed back to the shutter speed control circuit one after another, it may be backlit or overexposed depending on where on the screen the light is measured. Since only one set of the light amount adjustment function can be selected for each moment during shooting, if a still image is shot using only the light amount adjustment control, it may be difficult to obtain the exposure intended by the photographer. ..

Therefore, an object of the present invention is to provide a camera that solves the above problems.

[0009]

In order to achieve the above object, the present invention provides a photometric means for executing a plurality of photometric methods and a still image under each recording condition based on each photometric value of the photometric methods of the photometric means. And a means for recording.

[0010]

According to the present invention, still images are successively recorded under recording conditions based on each of a plurality of photometric methods.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram of a camera capable of recording moving images and still images according to a first embodiment of the present invention. Figure 1
, 101 is a first lens group for focus adjustment, and 102
Is a zoom lens, 103 is a correction lens, 104 is an aperture, and 1
Reference numeral 05 denotes a fixed fourth lens group, 106 denotes an image pickup element, 10
7, 108 and 109 are motors for focus adjustment, magnification adjustment and aperture adjustment, 110, 111 and 112 are drivers for driving the respective motors 107, 108 and 109, and 113, 114 and 115 are lens positions. And an encoder for detecting the diaphragm state, 116 is A
The GC circuit 117 is a high-pass filter. 11
Reference numeral 8 is a comparator for adjusting the aperture, which outputs a photometric value to a microcomputer (microcomputer) 119. 120,
121, 122, 123 are pull-up resistors, 124 is a zoom tele switch, 125 is a zoom wide switch, 1
Reference numeral 26 is a switch for switching between still (still image) and movie (moving image) shooting modes, and 127 is a still shooting release switch. Further, 129 is an image memory for capturing a still image, 130 is a control circuit for starting or clearing memory writing according to the timing of release or recording, and 131 is suitable for recording the output of the memory 129 on a tape. Circuit for converting to a different signal, 132 is an amplifier, 1
33 is a head and 134 is a recording tape.

Reference numeral 135 is an amplifier, 136 is a gate circuit for passing only a specified partial area in a captured image area, 137 is a peak hold circuit, and 138 is a reference voltage.

First, a procedure for photographing a still image will be briefly described.

FIG. 5 is a conceptual diagram thereof. A field or frame (image) memory 129 temporarily stores a still image, and when the release button is pressed, the image at that moment is captured in the memory 129. The captured video signal is recorded in the PCM area of the tape as described in the conventional example. At this time, the first still image is sequentially recorded in the areas 501, 502, and 503 on the tape. It is said that this recording usually requires a time of ten to several tens of vertical synchronization periods.

FIG. 2 is a drawing showing the structure of a camera including the camera section shown in FIG.
2 is a zoom switch having the same function as the switches 124 and 125, 203 is a release switch for shooting a still image, and 204 is a switch for selecting the bracket still image shooting mode or the normal still image shooting mode proposed in the present invention. ..

In bracket shooting, a method for shooting a still image in a state in which the photometric system becomes a preset system every time the release switch 203 is pressed will be described below.

FIG. 3 is a divided view of the photometric area necessary for performing this processing.

In FIG. 3, reference numeral 301 denotes the entire photometric area, that is, the entire area of the screen to be photographed.
Reference numerals 3, 304, 305, and 306 are partial photometric areas divided within 301 as shown in the figure. When 301 is selected as the photometric area, average photometry is performed over the entire area, and when 306 is selected, average photometry is performed only within the area 306. That is, the average photometry in the area other than 301 means so-called partial photometry in the area.

FIG. 4 is a flow chart of a photometric method, particularly a work for photographing a still image by changing the photometric area.

When the switch 204 is in the bracket photographing mode in FIG. 2, the work is started at 400 in FIG. First, in 401, it is judged whether it is Rec Pause, and Rec
If it is Pause, proceed to 403, and if not, proceed to 402. Four
In 02, it is determined whether or not the release button is pressed. If not, in 403, the entire photographing area, that is, the area 301 is averaged, and the measured value is stored. Further, in 404, the state of the diaphragm at this time is indicated by the encoder 11
It is fetched as the output value of No. 5, converted to the F value at 405, and stored as the value B in the corresponding memory address of the microcomputer 119. Next, in 406, average photometry (partial photometry) in the 306 area is performed, and in 407, this photometric value and the photometric value stored in 403 are compared. The value obtained as a result is converted to an aperture value at 408, and stored at 409 as the partial photometry result A of the 306 area in the corresponding memory address.

Next, at 410, 302, 303, 304,
Average photometry is performed in the combined area of 305, and at 411, comparison with the stored photometric value of 403 is performed. Furthermore, the value of the comparison result is converted into an aperture value (412), and this is stored in the corresponding memory address as the partial photometry result C of the combined area (4
13) and return to 401.

Now, a method of converting the photometric value into the F value will be described.

In FIG. 1, the output of the image sensor 106 is
Unless correction or saturation is applied, the level will be proportional to the amount of light. This value is amplified by the amplifier 135, and the gate circuit 136 allows only the signal in the target photometric region to pass. The peak value of the passed signal is detected by the peak hold circuit 137 and input to the microcomputer 119.

In general, the required Fno. Is given by equation (1).

(Proper Fno.) = (Current Fno.) × (Current video level / Proper video level) ^1/2 (1) Therefore, in the microcomputer 119, the result of 405 and the output of the peak hold circuit 137. If the value of the reference voltage 138 and the value of the reference voltage 138 can be grasped, an appropriate Fno. Can be obtained, and B and C can be determined by 409 and 410 as in the present embodiment.

As described above, when it is confirmed that the release switch has been pressed at 402 with A, B, and C determined, the Fno. Make sure all the shooting in is completed. At first, of course, it is not completed, so proceed to 415, and take the shooting Fn first.
o. Call A as. Then at 416, this Fno.
The diaphragm is moved until the output value of the encoder 115 indicates the value of. When the movement of the diaphragm is completed, a still image is photographed at 417 and the process returns to 414. If it is determined in 414 that the shooting has not been completed, a new aperture value B is called again in 415, and the same operation is repeated. As described above, the Fno. This work is completed when it is determined that all of the shooting in (1) have been completed.

By performing the above-described processing, center-weighted metering, full-screen averaged metering, background-weighted metering, and several metering methods are selected, and a plurality of still images are photographed at aperture values suitable for the respective methods. it can.

In the present embodiment, the method of changing the aperture value by changing the photometric method has been described, but by the same method, all the factors that can be changed depending on the photometric method, such as the storage time of the image sensor, can be changed. It is obvious that still images can be taken continuously. Further, in this embodiment, it is premised that a plurality of still images can be continuously recorded by one release operation. When the recording time and the still image capture timing must be taken into consideration, it is necessary to take appropriate measures such as adding an image memory or controlling the recording timing, but the description thereof is outside the scope of the present invention. I omitted it.

[0030]

As described above, according to the present invention,
It is possible to record multiple still images by sequentially changing the photometric method, which maintains the immediacy of recording (shooting).
For each subject, it becomes possible to obtain an image without blackouts and underexposures, and you can select an image that has been captured well later, or by combining images, you can broaden the dynamic range with respect to the amount of light. Things will be possible.

[Brief description of drawings]

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

FIG. 2 is an external view of the embodiment.

FIG. 3 is a diagram showing a photometric area.

FIG. 4 is a flowchart showing the operation of the embodiment.

FIG. 5 is a diagram showing a recording area of a memory and a tape.

FIG. 6 is a diagram showing a tape traveling system of a VTR.

FIG. 7 is a diagram showing a recording track on a tape.

[Explanation of symbols]

 106 Image sensor 119 Microcomputer 136 Gate circuit 137 Peak hold circuit 138 Reference voltage

Claims (1)

[Claims] 1. A photometric unit for executing a plurality of photometric methods,
A camera for recording still images under recording conditions based on photometric values of a plurality of photometric methods of the photometric means.