JPH078024B2 - Electronic camera - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electronic camera having both a still image pickup function and a movie image pickup function.

[Prior art]

Generally, in an electronic camera having both a still image pickup function and a movie image pickup function, in the case of movie image pickup, for example, in the case of the NTSC system, it is 1/30 second or 1/30 second.
The image output is read from the image sensor every 60 seconds. Therefore, imaging is performed in a cycle corresponding to the cycle of the above-described read operation of the imaging output (1/30 seconds or 1/60 seconds described above). On the other hand, in the case of still image pickup, the shutter speed can be arbitrarily set so that a moving subject can be shot without blurring.

Regarding this type of electronic camera, it is conceivable that a general low-luminance side limit or high-luminance limit is displayed in the field of view of the field to give a warning to the photographer regarding the brightness of the outside world. High brightness warning, suitable for still imaging
It was confirmed that if the display was set to give a low-brightness warning, a correct warning could not be obtained when shooting a movie, resulting in overexposure or underexposure.

〔Purpose〕

The present invention has been made in view of the above problems, and an object thereof is to eliminate the drawbacks of the conventional example. In particular, it is an object of the present invention to provide an electronic camera capable of always performing proper exposure on an image sensor by controlling the range of the proper exposure level in each of still image pickup and movie image pickup.

〔Example〕

The present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram showing an embodiment of the present invention. 1 is a photometric circuit, 2,
Reference numeral 7 is a comparator, 3 and 23 are indicators such as LEDs, and 4 and 6 are switches that switch between S and M in accordance with the output of the still image capturing mode S and the movie image capturing mode M switching switch 22, respectively. It is controlled by the output of. Five,
8 is a transistor, 9 is a subject, 10 is a photographing lens, 11 is an aperture, an exposure control circuit (member) including a shutter, 12 is a CC
D image pickup tube, image pickup device such as MOS image sensor, 13 is a process circuit for adding various corrections to the image pickup device output,
14 is a recording circuit for converting the output of the process circuit 13 into a signal suitable for recording, 15 is a head, 16 is a recording medium, and 17 is a recording medium.
Is a motor for driving the rotation of this medium, 18 is a motor control circuit for controlling the rotation speed and rotation phase of the motor 17, and 19
Is a driver for supplying a pulse of a predetermined width and a predetermined level to the image pickup device 12, 20 is a clock generator for sending a timing signal to the driver 19, and 21 is a microcomputer for performing sequence control of the entire apparatus. A sequence control circuit (controller), 24 is a light receiving element such as SPC (silicon photocell), and 25 is an exposure time setting circuit.

The operation will be briefly described below.

First, the light from the subject 9 is imaged by the taking lens 10 and converted into an electric signal by the image pickup device 12. Here, in front of the image sensor 12, an exposure control circuit 11 including a diaphragm, a shutter, etc. is provided to control the amount of light incident on the image sensor 12 and the like. The output of the image sensor 12 is the process circuit.
After various corrections are applied by 13, the recording signal is converted into a recording signal of an appropriate form by the recording circuit 14 and recorded on the recording medium 16 via the head 15. The medium 16 is rotationally driven by a motor 17, and the motor 17 is subjected to servo control of rotation speed / phase by a motor control circuit 18.

The image pickup device 12 is driven by the pulse from the driver 19 in accordance with the standard television cycle. Driver 19 has
Various timing pulses are supplied from the clock generator 20, and the clock signal from the pulse generator 20 is also input to the sequence control circuit 21.
The entire apparatus is controlled by the sequence control circuit 21, and when the steal mode S is selected by the mode switching switch 22, each circuit records a steal image through the sequence control circuit 21, and the movie mode M is changed. If selected, record consecutive images.

Here, if the mode switching switch 22 is connected to the steel side S, the switches 4 and 6 are also connected to the steel side S, and if the switch 22 is switched to the movie side M, the switches 4 and 6 are also to the movie side. Switch to M.

Further, when the switch 22 is connected to the steel side S, the exposure time setting circuit 25 outputs the exposure time information previously set in the manual, and if it is set to "1/120", for example, this exposure time is set. The shutter in the exposure control circuit 11 is controlled so that 1/120 seconds can be obtained.

On the other hand, when the mode switching switch 22 is connected to the movie side M, the exposure time setting circuit 25 automatically controls the exposure control circuit 11 so that the exposure time becomes 1/60 seconds or 1/30 seconds.

In the PAL system or SECAM system, in this movie mode M, the exposure time is 1/50 seconds or 1/25 seconds.

On the other hand, the photometric circuit 1 forms the brightness information V _X of the subject 9 according to the output of the SPC 24. The brightness information V _X is input to the exposure control circuit 11 to control the exposure amount by the diaphragm and the shutter.

Here, the comparators 2 and 7 form a window comparator, and in the steal mode S,
If the brightness information V _X is between V _SL <V _X <V _SH (V _SL and V _HL are the low brightness and high brightness limit values in the steel mode, respectively), transistors 5 and 8 are turned off and LEDs 3 and 23 are turned on. Turn off.

When V _X <V _SL , the transistor 8 is turned on, the LED 23 is turned on, the transistor 5 is turned off, and the LED 3 is turned off to give a low brightness warning.

When V _X <V _SH , the transistor 8 is turned off, the transistor 5 is turned on, the LED 23 is turned off, and the LED 3 is turned on to give a high brightness warning.

In the present invention, the brightness information V _SL , V _{SH in} the steal mode is used.
On the other hand, V _SL <V _ML <V _MH <V _SH (V _ML and V _MH are the low and high brightness limit values in movie mode, respectively) are related to V _ML and V _SH. By switching, it is possible to display whether or not the optimum exposure is appropriate in the still mode and the movie mode.

FIG. 2 and FIG. 3 schematically show warning display examples for reference. FIG. 2 shows a display state of the low-brightness warning display device, and FIG. 3 shows a display state of the high-brightness warning display device. The lighting state of the display is shown according to the level of each output voltage V ₁ , V ₂ , V ₃ from the photometric circuit with respect to each reference voltage V _S , V _M. For example, in FIG. 2, the output voltage from the photometric circuit
When V _X is the voltage V ₂ between the standard voltages V _SL and V _ML ,
In the movie mode, the indicator lights up, and in the case of steel mold, the indicator does not light up.

In the embodiment, the warning is displayed outside the proper exposure range, but the warning may be displayed not only but the recording of the image pickup signal may be prohibited.

〔effect〕

As described above, according to the present invention, the control level of the proper exposure range is switched between the still image pickup and the movie image pickup, so that the exposure is blocked when the movie is shot with a relatively narrow dynamic range. There is no over or under exposure.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, and FIGS. 2 and 3 are schematic diagrams showing states of a low brightness warning display and a high brightness warning display, respectively. 1 …… Metering circuit 2,7 …… Comparator 3,23 …… LED (display) 4,6 …… Switching switch 5,8 …… Transistor 9 …… Subject 11 …… Exposure control circuit 16 …… Recording medium 21 ...... Sequence control circuit 22 …… Shooting mode switching switch

Claims (1)

[Claims] 1. A switching means (22) for switching between a still recording mode for capturing and recording a still image and a movie recording mode for capturing and recording a moving image, and a detecting means (1) for detecting the brightness of a subject. By comparing the output of the detecting means with an exposure amount control means (11) for controlling the exposure amount according to the output of the detecting means, the output of the detecting means is controlled by the exposure amount controlling means. Output means (2, 7) for outputting a signal indicating this when it is outside the proper exposure range between the high brightness limit value and the low brightness limit value, and the still recording mode and the movie recording mode by the switching means. The appropriate exposure range between the high brightness limit value and the low brightness limit value in the exposure amount control means in the movie recording mode is narrower than the optimum exposure range in the still recording mode. And a control means (4, 6, 23) that displays a warning or prohibits recording when it detects that the value is out of the proper range based on the output of the output means. Electronic camera.