JPH0313071A - Zoom camera - Google Patents

Abstract

PURPOSE:To decrease the peak of power consumption by applying alternately the movement of a zoom lens and aperture. CONSTITUTION:A photometry circuit 21 measures an object 1 from an output of a photodetector 29, the result of photometry is outputted to a microcomputer 22 to decide a proper exposure. An aperture drive circuit 8 drives an aperture motor 7 corresponding to the calculated exposure. Then the microcomputer 22 starts a built-in timer to execute the zoom processing. After a prescribed time elapses, the drive of the zoom motor 5 is stopped and the processing for deciding exposure is repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a zoom camera having a zoom function.

[Conventional technology]

In electronic still cameras that have become popular in recent years, one frame (one field or two fields) of video is recorded on one track of a magnetic disk.

Therefore, the magnetic disk has a period of one field (NTSC
In the case of the 1;

Since the magnetic disk as a recording medium is rotated at such a high speed, a large number of frames (for example, 1, 2, or 5 frames) can be recorded in one second for a desired amount of time.

You can take pictures continuously (continuous shooting).

By combining this continuous shooting mode with zooming, images are gradually enlarged or reduced.

Capable of shooting continuously.

Furthermore, at this time, by setting a monitor mode in which the image read out from the image sensor is displayed on the monitor, changes in the image can be confirmed before actually photographing.

By the way, when zooming, the brightness changes as the angle of view changes, making it necessary to change the aperture.

[Problems to be Solved by the Invention] However, when performing zooming in conventional electronic still cameras, the aperture is controlled while moving the zoom lens, so the imaging circuit, recording circuit, The throttle motor, tracking motor, spindle motor, etc. are operated at the same time, which has the drawback of increasing the peak value of current consumption.

For this reason, the load on the power supply circuit increases, and its rated capacity must be increased, which not only increases its size but also
It had the disadvantage of high cost.

This invention was made in view of this situation,
This enables zooming without increasing the size and cost of the device.

[Means for Solving the Problems] A zoom camera of the present invention includes: a zoom switch means that is operated when driving a zoom lens; a zoom drive means that drives the zoom lens in response to the operation of the zoom switch means; When commands are given to drive the photometry means that measures the light of the subject, the aperture drive means that drives the aperture in response to the photometry results of the photometry means, and the zoom lens, part 1! ! The zoom lens is driven again after the aperture is driven according to the photometry result of the 1flll light means.

A control means for controlling the zoom drive means and the aperture drive means is provided.

[Effect]

In the zoom camera configured as described above, the zoom lens is moved in the telephoto direction or the wide direction by the zoom drive means such as a zoom motor in response to the operation of the zoom switch means such as a teleswitch or a wide switch. Ru.

For example, the zoom lens is moved for a certain period of time and then stopped. While the zoom lens is stopped, the diaphragm is driven by an aperture driving means, such as an aperture motor, in accordance with the photometry result of the photometry means. After driving the aperture is completed, the zoom lens is moved again for a certain period of time.

In this way, the zoom lens and aperture are driven alternately and not at the same time, making it possible to reduce the peak value of the drive current, making it possible to reduce the capacity and shape of the power supply circuit, thereby reducing costs. .

〔Example〕

FIG. 1 is a block diagram showing the configuration of an embodiment in which the zoom camera of the present invention is applied to an electronic still camera.

In the figure, 2 is a zoom lens, and the light from the subject 1 is passed through an aperture 3 to an image sensor 4 made of COD or the like.
Inject it into the

A zoom motor 5 drives the zoom lens 2, and is driven by a zoom drive circuit 6. Also.

Reference numeral 7 denotes an aperture motor that drives the aperture 3, and is driven by an aperture drive circuit 8.

Reference numeral 9 denotes an imaging circuit that reads out a signal captured by the imaging element 4 and outputs it to the signal processing circuit 10 .

11 is an encoder, which outputs the output of the signal processing circuit 10,
For example, it is encoded into an NTSC television signal and supplied to the monitor 12.

A recording circuit 13 records the signal output from the signal processing circuit 10 onto a magnetic disk 15 via a magnetic head 14.

A spindle motor drive circuit 16 drives a spindle motor 17 that rotates the magnetic disk 15. 1
8 is a tracking motor drive circuit, and magnetic head 1
4 is driven.

A track detection circuit 20 detects the level, DPSK signal, control code signal, etc. of the reproduced signal output from the magnetic head 14, and outputs the detected signals to a microcomputer 22 serving as a control means.

21 is a photometry circuit that measures the light of the subject 1 and outputs the result to the microcomputer 22;

Reference numerals 23 and 24 denote a tele switch (E SW) and a wide switch (WIDE SW), which are operated when moving the zoom lens 2 in the tele direction or the wide direction. 25 is a mode selection switch operated when setting various shooting modes, and 26 is a release switch, which performs a series of recording operations (photometering, exposure calculation, aperture drive, image sensor U exposure, readout, recording, track movement, etc.) It is operated when performing.

The release switch 26 includes, for example, a two-stage switch, and when the first stage switch is turned on.

After photometry, distance measurement, and exposure calculation are performed, when the second stage switch is turned on, subsequent image recording operations begin.

Reference numeral 27 denotes a power supply circuit having a battery inside, and supplies necessary power to each circuit, means, etc.

28 is an optical finder for checking the subject 1, and has a light receiving element 29 for photometry inside.

Next, referring to the flowcharts in FIGS. 2 and 3,
Let's explain its operation.

Light from subject 1 is transmitted through zoom lens 2. The light enters the image sensor 4 via the aperture 3. The signal photoelectrically converted by the image sensor 4 is read out to the image sensor 9 and sent to the signal processing circuit 1.
It is input to 0. The signal processing circuit 10 processes the input signal into a signal compatible with the format of the electronic still camera.

When the monitor mode is set by the mode changeover switch 25, the signal processed by the signal processing circuit 10 is input to the encoder 11, and the signal processed by the signal processing circuit 10 is inputted to the encoder 11.
The signal is converted into a signal in the format of the system and output to the monitor 12. In this way, the subject 1 can be monitored using the monitor 12.

In this way, when the monitor mode is set, the photometry circuit 21 measures the subject 1 from the output of the light receiving element 29,
The photometry results are output to the microcomputer 22. The microcomputer 22 calculates the signal input from the photometric circuit 21.

An appropriate exposure amount is determined (steps S1 and S2).

If this calculated exposure amount has already been set, the exposure amount is left as is; however, if the set exposure amount differs from the calculated value, the aperture drive circuit 8 adjusts the calculated exposure amount to Correspondingly, the throttle motor 7 is driven (S3, S4
), whereby the aperture 3 is moved to a position where a predetermined exposure can be obtained.

Therefore, images are always displayed on the monitor 12 with proper exposure.

Next, the microcomputer 22 starts a built-in timer and executes zoom processing (S5, S6).
.

That is, when the tele switch 23 is turned on, if the limit switch (not shown) in the tele direction is not turned on, the microcomputer 22 drives the zoom motor 5 via the zoom drive circuit 6, and the zoom lens 2 is moved in the telephoto direction (S21.S22.523).

If the tele switch 23 is turned off, the operation of the wide switch 24 is determined (S21.524); if the wide switch 24 is turned on and the limit switch in the wide direction (not shown) is not turned on, , the zoom lens 2 is moved in the wide direction (S25, 526)
.

No matter which direction the zoom motor 5 is moved, when the limit switch is turned on, the drive of the zoom motor 5 is stopped (S22.S25.527).

Such zoom processing is performed until the timer measures a predetermined time set in advance or the release switch 26 is turned on (S7 and S8).

When a predetermined time has elapsed, the drive of the zoom motor 5 is stopped, and the processes from step S1 onwards are repeated (S
10).

Before the timer's predetermined time elapses, release switch 2
6 is turned on, release processing is executed (SS,
S9).

That is, the signal output from the image sensor 4 at this time is input to the signal processing circuit 1o via the image sensor 9. The signal converted by the signal processing circuit 10 into a signal compatible with the format of the electronic still camera is input to the recording circuit 13 and subjected to FM modulation.

This signal is further supplied to the magnetic head 14.

At this time, the microcomputer 22 drives the spindle motor 17 via the spindle motor drive circuit 16 to rotate the magnetic disk 15 at a speed of 360 rpm. Therefore, one frame of image is recorded on a predetermined one (one field) or two (two fields) tracks of the magnetic head 14.

When this recording is completed, the microcomputer 22
The tracking motor 19 is driven via the tracking motor drive circuit 18 to move the magnetic head 14 onto the magnetic disk 1.
5 to the inner track. Then, the signal is reproduced from the moved track. This reproduction signal is input from the magnetic head 14 to the track detection circuit 20.

The track detection circuit/circuit 20 detects the level of the reproduced signal and outputs it to the microcomputer 22. The microcomputer 22 determines from the signal input from the track detection circuit 20 whether or not another image signal has already been recorded on the track.

If recording has already been done, the magnetic head 14 is moved to the next empty track. In this way, the magnetic head 14
It is confirmed that one image data can be recorded on the track where is located.

After the release process is executed in this way, the process returns to step S1.

Although the present invention has been described above with reference to an example in which it is applied to an electronic still camera, the present invention can also be applied to ordinary cameras that take pictures on film, video cameras, and the like.

〔Effect of the invention〕

As described above, according to the zoom camera of the present invention, since the zoom lens and the aperture are moved alternately, the peak of power consumption can be reduced. As a result, not only the capacity but also the shape of the power supply circuit can be reduced, and the device can be made smaller, which is advantageous for portability. Also, costs are reduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment in which the zoom camera of the present invention is applied to an electronic still camera; FIG. 2 is a flowchart illustrating the monitor mode processing operation of the embodiment of FIG. 1; FIG. 3 is a flowchart illustrating more detailed processing steps of the zoom processing operation in FIG. 2...Zoom lens 3...Aperture 4...Imaging element 6...Zoom drive circuit 8...Aperture drive circuit 9...Imaging circuit 10...Signal processing circuit 12...Monitor 14 ... Magnetic head 15 ... Magnetic disk 22 ... Fist microcomputer 23 ... Tele switch 24 ... Wide switch 25 ... Mode changeover switch 26 ... Release switch 27 ... Power supply circuit 2nd figure

Claims (1)

[Scope of Claims] A zoom switch means that is operated when driving a zoom lens; a zoom drive means that drives the zoom lens in response to the operation of the zoom switch means; and a photometer that measures the light of a subject; an aperture driving means for driving an aperture in response to a photometry result by the photometry means; and an aperture drive means for temporarily interrupting the driving of the zoom lens when a command is given to drive the zoom lens; A zoom camera comprising: a control means for controlling the zoom driving means and the aperture driving means so as to drive the zoom lens again after driving the zoom lens.