JPH0728385B2 - Electronics - Google Patents

Description

The present invention relates to an electronic device that can be optimally driven according to the state of a power supply.

[Prior art]

Because electronic devices such as electronic cameras use batteries as power sources,
If a large current is applied, the voltage may drop. This tendency is especially great at the end of battery discharge, at low temperatures, and the like.

Therefore, it is conceivable to drive some motors and the like in the electronic camera so that their power consumptions (or their peaks) do not overlap.

[Problems to be solved by the invention]

However, according to this driving method, since the operation is sequential, the image pickup and recording operations are delayed,
The release standby time, the release time lag, the return time of the tight turn mirror in the case of the single-lens reflex type, and the continuous shooting frames will be slow.

An object of the present invention is to solve these problems and to provide an electronic device that reduces malfunctions due to rapid battery drop while reducing time loss.

[Means for solving problems]

In order to solve such a problem, the present invention discriminates a first state in which the power supply capacity is lowered and a second state in which the power source is not lowered, and a power supply to a plurality of drive sources by the output of the discriminating means. The electronic device has a control means for switching whether to perform at substantially the same time or sequentially at predetermined intervals.

[Action]

The determination means determines whether or not the power supply capacity has deteriorated, and the control means controls the switching of whether to feed power to a plurality of motors at substantially the same time or sequentially at predetermined intervals. Therefore, when the power supply capacity is sufficient, the entire system can be operated at high speed. On the contrary, when the power capacity is reduced, the operation of the entire system is slowed to prevent the power supply from being suddenly shut down, so that the life of the power supply can be extended.

〔Example〕

FIG. 1 is a diagram showing a configuration example of an image pickup apparatus of the present invention. In the figure, 1 is a body, 2 is a lens barrel, 3 is a diaphragm, 4 is a quick return mirror, 5 is a shutter unit, 6 is an image sensor, and 7 is LCD for display, 8 for 2-stroke release switch, 9
Is a magnetic disk drive unit, 10 is a continuous shooting mode switching operation unit, 11 is a color temperature detecting sensor window, and 25 is a battery or an AC adapter pack. SW3
Is a switch for discriminating the two as described later.

The battery is a first power source that can discharge a relatively large current, and the AC adapter is a second power source that can discharge a relatively low current. FIG. 2 is a diagram showing an example of a circuit configuration of the image pickup apparatus of the present invention. Reference numeral 12 is a diaphragm driving apparatus which outputs a signal U upon completion of opening the diaphragm. A mirror driving device 13 outputs a signal V upon completion of mirror down. 14 is a shutter drive device, 15 is a signal processing circuit for processing the output of the image pickup device 6, 16 is a recording device, and the control device 17 outputs a head shift signal Hs to drive a step motor described later to shift the head. When the head shift is completed, the signal HC is output and input to the control device 17. Further, 116 is a color temperature sensor that detects the color temperature of light incident through the sensor window 11, and 19 is a part of the light that is guided to a finder optical system (not shown) through the quick return mirror 4. A photometric device for measuring subject brightness.

Reference numeral 17 is a control circuit, which has a built-in microcomputer. Reference numeral 18 is a disk motor control circuit for controlling the rotation of the magnetic disk in the recording apparatus. The recording medium may be a tape-shaped medium instead of a magnetic disk, and the head may be rotated at a high speed instead of fixing the head and rotating the disk at a high speed.

Further, the release switch 8 includes a switch SW1 which is turned on in the first stroke and a switch SW2 which is turned on in the second stroke.

Also, the continuous shooting mode switching operation unit 10 is a single shooting S, low speed (2 frames /
It has 3 modes: second) L and high speed (10 frames / second) H,
It is configured so that it can be selectively switched to one mode.

Further, 20 is a battery, 21 is an AC adapter, and there is a recess A in the AC adapter as shown in FIGS.
Since it is not in the battery, SW3 is turned off when the AC adapter is used.
Turns on when it is a battery. 209 is an electrode. Reference numeral 22 is a regulator that supplies power to a disk motor or the like, 23 is a DC / DC converter as a booster circuit that supplies power to an image sensor or the like, and Q ₁ and Q ₂ are switching transistors. Battery 20 and AC adapter 21 are selectively connected to terminals 24a and 24b. The transistor Q ₁ is turned on by turning on SW ₁ or Q _{2 which} is linked with the switch SW 1 described above, and the output of the battery or AC adapter is input to the regu- lator 22 and stabilized to stabilize each circuit (for example, the disc motor in the disc motor control circuit). ) Is supplied to. Further, when the SW1 is turned on, power is supplied to the DC / DC converter, the voltage is boosted by the converter 23, and it is used as a power source for driving the image pickup device 26, for example.

The battery may be rechargeable or non-rechargeable as long as the discharge current amount is large,
Also, the AC adapter may simply have a small discharge current.

R1 and R2 are voltage divider resistors that divide the level of the power supply supplied to the regulator, COMP is a comparator, Vref is a reference voltage, and comparator COMP outputs high if the power supply level is higher than Vref, and outputs low if it is lower. Output as signal BE.

Next, FIG. 3 is a diagram showing a configuration example of a main part of FIG.

First, in the signal processing circuit 15, 20a to 20c are controlled by the sample and hold circuits which are shifted by 120 ° from each other. R, G, and B stripe filters are attached to the front surface of the image sensor in the vertical scanning direction, and the width of each stripe filter corresponds to the width of each pixel. Therefore, since the horizontal line signal of the image pickup device 6 is composed of R, G, B dot-sequential signals, the R, G, B signals are separated by the sample hold circuits 20a to 20c.

21a to 21c are LPFs having a cut-off characteristic of 0.5MHz, 23 is 3
The luminance signal Y is formed by an LPF having a cutoff characteristic of MHz. 22a and 22b are gain control amplifiers provided in the R channel and B channel, and 27 is a matrix of Y, R, G, and
Form the Y, RY, and BY signals from B. 28 forms a color video signal that is multiplexed in the encoder, which signal is
Record 1 field by 1 track on the disk 30 via 29. 31 is a disk motor that rotates at 3600 rpm, and generates 15 periodic FG pulses at regular intervals per rotation.

A step motor 301 is a step motor for rotating the motor to carry out a head shift by a head carriage.
A head is provided on the head carriage.

Reference numeral 32 denotes a white diffusion plate fitted in a window provided in the camera body, which forms ambient light (light source light). Reference numerals 33 and 34 denote R filters and B filters, respectively, for making red light and blue light incident on the light receiving elements 35 and 36, respectively. 37 and 38 output I _R of the light receiving element 35, 36 by a logarithmic amplifier, logarithmically compressed with respectively amplify the I _B, log I _R, to form a log I _B.

39 is a subtractor, To form. I _R / I _B corresponds to the color temperature, 40 is this l
og the (I _R / I _B) in the A / D converter for converting A / D, the color temperature signal via the converter is input to the control circuit 17.
Further, the converter 40 samples the output of the subtractor 39 with the FG pulse and converts it into a digital signal.

The control circuit 17 controls the gains of the gain control amplifiers 22a and 22b based on this color temperature signal. That is, when I _R / I _B becomes large, the color temperature becomes low, so the gain of the gain control amplifier 22a is decreased, and conversely, the gain of the gain control amplifier 22b is increased.

Next, FIG. 4, FIG. 5, and FIG. 6 are flow charts showing a sequence example of control by the control circuit 17. FIG. 7 is a diagram showing an example of the white balance subroutine. FIG. 9 is a timing chart showing the power supply timing. First, wait until SW1 turns on at step S40, then turn it on.
Then, in step S41, the P line of the control unit is set to high and the transistor Q ₂ is turned on to keep the power supply to the regulator. Then, switch SW3 turns on at step S42.
See if or not. SW3 is turned on in the case of battery backup, so at this time the motor is started by the disk motor control circuit 18 in step S43. , The motor has a relatively large first
Current I ₂ (Fig. 9 (a)) is applied. (Note that I ₁ is the controller 17
Is the current flowing through. ) After that, the current I ₁ is reduced to I ₃ in S431 to perform servo control, and then in step S44, a constant T _{1 is} waited for, and then in step S4.
At 45, the q line of the controller is set to high to start the DC / DC converter. At this time, a maximum current of I ₁ + I ₃ + I ₄ flows.

After this, at step S46, a constant T _{2 is} waited for, and the routine proceeds to the next step S53 in FIG.

On the other hand, when the AC adapter is connected, NO is set at step S42, and the q line is made high at step S47 to start the DC / DC converter. At this time, the maximum current I ₁ + I ₄ flows.

After this, wait for T ₃ (constant) (step S48) to start the disk motor by the motor control circuit 18. At this time, the second current whose current supplied to the motor is smaller than the first current
I ₅ This is because when the AC adapter is connected, it is not necessary to start the disk motor so quickly because it is at home, and the current is kept low. A specific method for switching the first and second currents is, for example, that the first current directly leads the current from the power source to the motor, and the second current passes the current from the power source through the attenuator. Switch to switch to the motor. Next, in step S491, the current I ₅ is reduced to I ₃ to switch to servo control, and then in step S50, the process waits for a constant T ₄ and then proceeds to step S53.

As described above, according to the embodiment of the present invention, when the battery is used, the DC / DC converter is started after the disk motor is started up first. Therefore, the time required for imaging and recording is short, and conversely, the AC adapter is used. In the case of, since the DC / DC converter is started first and then the motor is slowly started up, it takes time to start up, but the maximum current is small and it can be a small, simple AC adapter.

After that, photometry (step S53) and white balance routine (step S54) are performed. That is, in the photometric step, the light entering through the diaphragm 3 and the mirror 4 is received by a light receiving element (not shown) and integrated, whereby the subject brightness level is increased.
While detecting Bv, the preset shutter time Tv is calculated and the aperture value is determined by the algorithm Av = Bv-Tv. In the white balance routine, as shown in FIG. 6, first, in step S541, the digital value of the color temperature information input to the control circuit 17 is integrated for 25 msec at each FG pulse timing. In step s542, the integrated value C _A
Is stored in a memory M _A (not shown) in the control circuit. In step S543, the data in the memory MA and the memory M _B
The data inside is added to form color temperature data C ₀ for 50 msec, and the gains of the amplifiers 22a and 22b are controlled based on this data C ₀ .

Then, in step S544, the sample value for 25 msec is integrated again, and this integrated value C _B is newly stored in the memory M _B. (Step S545) Next, the data in the memory M _A and the updated data in the memory M _B are added to add new color temperature data C ₀ for 50 msec which is shifted by about 25 msec from the data C ₀ in step S543. And the gains of the amplifiers 22a and 22b are controlled based on this data C ₀ . (Step S546) Now, the reason why the integrated value for 50 msec in total is used as the color temperature data C ₀ is to remove the flickers due to the fluorescent lamp.

In other words, the commercial power frequency is 50Hz or 60Hz in Japan, and the flickers of fluorescent lamps are
Double the frequency. Further, since the color temperature also changes at the above frequency according to the flickers, the color temperature fluctuates unless the color temperature data for at least one cycle of the flickers is integrated. Further, if the integration time is too long, the responsiveness of white balance is deteriorated.

Therefore, when integrating the light of the flicker light source of 100Hz and 120Hz, which is double 50Hz and 60Hz, when the commercial power supply frequency is 50Hz Is required, and when the commercial power frequency is 60Hz, Integral of is required. Therefore, the least common multiple of both is 50
msec is the shortest integration time that can eliminate the flickers of both commercial power sources.

Further, in this embodiment, if the gains of the amplifiers 22a and 22b are controlled every 50 msec, the response of the white balance is poor. Therefore, the gain control is performed while taking in new color temperature data every 25 msec.

Now release Sui Tutsi SW1 at step S55 the subroutine in S54 the white balance is completed detects whether turned ON, and the jump P line low to step S67 if the OFF to cut off the power supply Q ₂ is turned OFF As a result, the disk motor is stopped and the program ends.

If the release switch SW1 is turned on in step S55, whether the release switch SW2 is turned on in step S56,
That is, it is detected whether or not the imaging and recording are triggered.

If the switch SW2 is not turned on, the process returns to step S53 to repeat photometry and white balance adjustment. In this case, as described above, the color temperature detection is integrated by 50 msec through the loop of steps S53, S54, S55 and S56, and the gain control is performed by 25 msec.

When the release switch SW2 is turned on, the mirror drive device 13 retracts the mirror from the photographing optical path at step S57, and the aperture drive device 14 determines the aperture based on the photometric data obtained at step S53 from the open state and the predetermined shutter time. Narrow down to the aperture value Av.

Next, the shutter is opened by the shutter drive unit 14 (step S60), and after the lapse of the shutter time Tv, the shutter is closed at step S61. In step S62, the output of the image sensor is recorded on the disk.

After that, the process proceeds to step S651, and the output BE of the comparator COMP is output.
Read. Then, when the power supply is reduced and BE is not at the high level in step S652, the motor 301 in the recording device 16 is driven in step S653 to move the head carriage 300 and shift the head one track.

When the shift for one track is completed and the head shift completion signal HC is output from the motor 301 (step S65
4) At step S655, the mirror is returned to the original position, and when the return is completed, the mirror driving device 13 obtains the mirror down completion signal V (step S656). Then, at step S657, the diaphragm driving device 12 opens the diaphragm. Step S658
When the diaphragm opening completion signal U is obtained from the diaphragm driving device, the process proceeds to step S66.

In this way, when the power supply voltage drops, the head feeding, the mirror restoration, and the aperture opening are sequentially performed so that the current consumption does not overlap. Therefore, there is no drop in voltage due to sudden discharge of current, and malfunction can be prevented.

If the power supply voltage has not dropped in step S652 and the output of the comparator COMP is high level, steps S659 to
In S661, the three operations of mirror return, head feed, and aperture opening are started almost at the same time.

Thereafter, in steps S662 to S664, the mirror return completion signal V, the head feed completion signal HC, and the aperture opening completion signal U are respectively waited, and then the process proceeds to step S66. As described above, when the power supply voltage is sufficiently high, the three operations of the mirror-down operation, the head feeding operation, and the aperture opening operation are performed substantially at the same time, so that the preparation for the next photographing can be completed quickly.

Then it is determined whether or not switch SW1 Proceeding to step 66 is ON, the output P of the control circuit 17 if not ON at a low level, and turns OFF the transistor Q ₂ (step S6
7) Stop holding the power supply and terminate the program.

On the other hand, if SW1 is ON at step S66, it is considered that there is an intention to continue shooting, and the process returns to step S53.

In the above embodiment, the output of the color temperature sensor is sampled at the timing of the FG pulse for A / D conversion for white balance, so a special sampling pulse is created by the synchronization signal generator for sampling. No need to
In addition, there is an effect that the speed control of the motor by the control circuit and the white balance control described above can be easily synchronized on the program.

In this embodiment, three operation controls of mirror return after image pickup, head feed, and aperture opening are sequentially performed at different times, but similarly, step S57, immediately before image pickup is performed.
The operation timings of the control of the diaphragm, the mirror, etc. in S58 may be sequentially set when the power is turned off, and may be set almost at the same time when the power is not dropped.

Further, in this example, the power supply timings for the plurality of drive sources are changed according to the first and second states of the battery. However, the power supply timings for the plurality of drive sources may be changed according to the state of the battery in more detail. May be.

〔effect〕

According to the present invention, the discriminating means discriminates whether or not the power state of the power source has deteriorated, and in accordance with the discriminating output, the control means switches the electric power supply to the plurality of motors substantially simultaneously or sequentially at a predetermined interval. is doing. Therefore, when the power supply capacity is sufficient, the entire system can be operated at high speed. On the contrary, when the power capacity is reduced, the operation of the entire system is slowed to prevent the power supply from being suddenly shut down, so that the life of the power supply can be extended.

[Brief description of drawings]

FIG. 1 is a configuration example diagram of an image pickup apparatus according to the present invention, FIG. 2 is a diagram showing a circuit example of the first illustrated configuration, FIG. 3 is a diagram showing a main part configuration of the second illustrated circuit configuration, and FIG. 5 and 6 are flow charts showing an example of a program of the image pickup apparatus of the present invention, and FIG. 7 is a view showing details of essential parts of the flow chart shown in FIG.
FIG. 8 (a) is a diagram of the AC adapter, FIG. 8 (b) is a diagram of the battery, and FIGS. 9 (a) and 9 (b) are timing charts when the battery is used and when the AC adapter is used. 10 …… Continuous shooting mode switching operation part, 11 …… Color temperature detection window, 16
...... Color temperature sensor, 20 …… battery, 21 …… AC adapter, COMP …… comparator.

Claims (1)

[Claims] 1. A plurality of drive sources, and a first state in which the power source has a capability lower than a predetermined level or a second state higher than a predetermined level before power supply to the plurality of drive sources is started. Determining means for determining, when starting power supply to the plurality of drive sources, power supply to the plurality of drive sources is started at substantially the same time in the second state according to the output of the determine means, and in the first state, An electronic device, comprising: a control unit that controls switching so that power supply to a plurality of drive sources is sequentially started at a predetermined interval in a predetermined order.