JPH0795822B2 - Imaging device - Google Patents

Description

The present invention relates to an image pickup apparatus capable of performing a quick still image pickup / recording operation without using interrupt processing.

[Prior art]

Conventionally, by a microprocessor (hereinafter abbreviated as CPU),
When controlling the sequence of the camera system, the interrupt function of the CPU was used. That is, when SW1 is turned on by half-pressing the shutter, the CPU performs disk drive, lens check, metering, automatic exposure calculation, display in the finder, etc. The results of photometry and automatic exposure calculation at this time are temporarily stored in a temporary storage area.
After disabling interrupts, move from the temporary storage area to the true storage area. After that, the interrupt is permitted again and the operation of confirming that SW1 is pressed is repeated. While in this loop, if SW2, which is the shutter release trigger, is pressed and an interrupt occurs, the CPU enters an interrupt routine, activates the release sequence, and shoots based on the information in the true storage area.

[Problems to be solved by the invention]

However, with this method, when the aperture value of the lens changes during a loop operation, for example, or when an interrupt occurs before the end of metering, the interrupt routine is jumped and shooting is performed, so correct exposure cannot be obtained. There were cases.

There is a problem that the above-mentioned temporary memory and true memory for performing the interrupt processing are required, and the memory capacity is doubled as compared with the case where the interrupt is not used, and there is a drawback that the program becomes complicated due to the interrupt processing. .

On the other hand, if you do not use the interrupt function, you cannot move to the shooting sequence without collecting various data such as photometric data and lens data.Therefore, even if you press the release switch to move to the shooting sequence, there is a time lag before it is actually executed. There was a drawback that there is.

[Means for solving problems]

The present invention relates to an image pickup means for picking up an optical image in an image pickup device,
Trigger means for starting the image pickup by the image pickup means, and a preparation step for preparing the image pickup prior to the start of the image pickup by the trigger means, and omitting the subsequent preparation steps in response to the trigger means during the preparation step. , A control means having a discrimination step for starting imaging.

[Action]

Since the control means has a preparation step for performing imaging preparation (for example, photometry, white balance adjustment, etc.) prior to the start of imaging by the trigger means, imaging can always be performed with correct exposure and setting conditions. Further, since the discrimination step is provided during the preparation step, when the trigger signal is generated by the trigger means, the subsequent preparation step is omitted and the imaging operation is started. Therefore, it is possible to quickly perform imaging without using interrupts.

〔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 pickup device, and 7 is an image pickup device. Is a display LCD, 8 is a 2-stroke release switch, and 9 is
Is a magnetic disk drive unit, 10 is a continuous shooting mode switching operation section, and 11 is a color temperature detecting sensor window.

FIG. 2 is a diagram showing an example of the circuit configuration of the image pickup apparatus of the present invention, in which 12 is a diaphragm drive apparatus, 13 is a mirror drive apparatus, 14 is a shutter drive apparatus, and 15 is a signal processing circuit for processing the output of the image pickup device 6. , 16 are recording devices. Also, 116 is the sensor window 1
A color temperature sensor for detecting the color temperature of the light incident via 1, and 19 for receiving the part of the light guided to the finder optical system (not shown) through the quick return mirror 4 to measure the subject brightness. Is a photometric device.

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.

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.

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 sample and hold circuits which are shifted by 120 ° from each other. RGB 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 RGB dot-sequential signals, R.R.
The GB signals are separated.

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 YRG matrix.
B to Y, RY, BY signals are formed. 28 forms a color video signal multiplexed by an encoder, and this signal records one field on the disk 30 via the head 29 one track at a time. 31 is a disk motor that rotates at 3600 rpm, and generates 15 periodic FG pulses at regular intervals per rotation.

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 are logarithmic amplifiers that amplify the outputs IR and IB of the light receiving elements 35 and 36, respectively, and compress them logarithmically.
Form logIR and logIB.

Reference numeral 39 is a subtractor, which forms logIR-logIB = logIR / IB. IR / IB corresponds to the color temperature, 40 is this log (IR / I
B) is an A / D converter that performs A / D conversion, and the color temperature signal via this 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, as IR / IB increases, the color temperature decreases, 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 is a flow chart showing an example of a control sequence by the control circuit 17. Further, FIGS. 5A to 5E are diagrams showing examples of each subroutine.

The program starts at step S50, and first, at step S501, information (for example, aperture value, zoom ratio, F number, etc.) on the lens 2 side is read. Next, in step S502, photometry is performed, and in step S503, white balance is 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 to detect the subject brightness level Bv and to calculate the preset shutter time Tv. The aperture value is determined by the algorithm Av = Bv-Tv. In the white balance routine, as shown in FIG. 5 (d), FG is first set in step S541.
The digital value of the color temperature information input to the control circuit 17 is integrated for 25 msec at each pulse timing. In step S542, the integrated value CA is transferred to the memory MA (not shown) in the control circuit.
Memorize inside. Further, by adding the data in the memory MB below the data in the memory MA at step S543 to form a color temperature data C ₀ of 50msec component, the amplifier based on the data C ₀
Controls the gain of 22a and 22b.

Then, in step S544, the sample value for 25 msec is integrated again, and the integrated value CB is newly stored in the memory MB (step S545). Next, the data in the memory MA and the updated data in the memory MB are added to add new color temperature data for 50 msec which is shifted by about 25 msec from the data C ₀ in step S543.
C ₀ is formed, 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 caused by 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, 1 / 100sec integration is required when the commercial power supply frequency is 50Hz, and 1 / 100sec when the commercial power supply frequency is 60Hz. 120sec integration is required. Therefore, 50 msec, which is the least common multiple of both, 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.

When the white balance routine S503 ends, the process waits until the release switch SW1 turns ON at step S51.
When turned on, the disk motor 31 is started in step S52, and it is determined in step S521 whether or not the rotation is stable, based on the known FG and PG signals from the motor control circuit. When it is stable, the flag F1 is set to 1 in step S522, and if it is not stable, the flag F1 is set to 0. After that, the AE and AWB routines are performed in step S524. This routine is a routine for automatic exposure control and automatic white balance, and an example thereof is shown in FIGS. 5 (a) to 5 (c).

That is, in the AE, AWB routine, in step S200, check whether release switch SW2 is ON and flag F1 = 1 (that is, whether imaging and recording are triggered and recording is possible). In step S201, the lens information is read. This is to perform exposure calculation and white balance with the latest data.

After that, the process proceeds to the photometry routine S202 and the auto white balance (AWB) routine S203, and the AE calculation step S204
Proceed to. In this AE calculation step S204, the AV value determined based on the photometric data is corrected with the latest lens data read in step S201. If YES in step S200, steps S201 to S204 are skipped.

Therefore, it is possible to shift to a photographing sequence described later in an extremely short time without waiting for the completion of all the sequences.

Further, the photometry routine S202 in FIG. 5 (a) is constructed as shown in FIG. 5 (b). In this routine S202 as well, there is the same step S205 as step S200, and if NO, photometry is performed. The metering is slowly performed at step S206, but YES
If so, do not perform photometry and proceed to S203 immediately.

The same applies to the automatic white balance routine S203 as shown in FIG. 5C, and when YES is determined by the determination of S207, which is the same as steps S200 and S205, the white balance (W
B) The routine proceeds to the display routine S525 without performing the routine S208.

Further, the white balance step S208 is assembled as shown in FIG. 5 (d) as described above.

Further, the display routine S525 is also step S2 as shown in FIG.
In 09, the same determination as in S200, S205, S207 is made, and if YES, the display step S210 is skipped and the process proceeds to step S55.

When the display routine S525 ends, step S55 detects whether or not the release switch SW1 is ON. If it is OFF, step S67 is skipped, the disk motor is stopped, and the program ends.

If the release switch SW1 is ON at step S55, the release switch SW2 is ON at step S56, and the flag F1
1 is detected, that is, whether or not imaging and recording are triggered and recording is possible is detected.

If it is ON, the process returns to step S524 again to repeat photometry, white balance adjustment, display and the like.

Release switch S with steps S56, S200, S205, S207, S209
When W2 is ON and F1 = 1, the imaging and recording sequence starts, and the mirror driving device 13 retracts the mirror from the photographing optical path in step S57, and the diaphragm driving device 14 obtains the aperture from the open state in step S502 or S206. Aperture value determined based on the measured photometric data and the predetermined shutter time
Narrow down to Av.

Then, in step S581, the white balance routine is executed again. This routine is the same as that shown in steps S541 to S546 in FIG. 5 (d).

Since the time from the start of execution of the mirror up operation and the narrowing operation to the mirror up operation and the narrowing operation in steps S57 and S58 is about 60 msec, the white balance operation can be sufficiently performed during this period.

Also, shortly after the white balance routine in step S581 is completed, when the sensor (not shown) detects completion of mirror up and completion of narrowing down, step S60
Proceed to.

At this step, the shutter is opened by the shutter drive device 14, and after the lapse of the shutter time Tv, the shutter is closed at step S61. Further, in step S62, the output of the image sensor is recorded on the disk, and in step S621, the head is recorded.
Shift 29 to the next empty truck on the disk.

After that, at step S63, the release switch SW2 turns on, and
If the flag F1 = 1 is checked again, and if YES, then in step S64 it is determined whether the high-speed continuous shooting mode is set or not.
Read from the S60 in the high-speed continuous shooting mode.
Then, the operation of opening and closing the next shutter, the head shift to the empty recording track, and the image recording and recording operations are repeated. At this time, not only the photometric value and aperture value (Av) but also the white balance state are fixed. Therefore, as described above, there is no deviation in the color balance condition when comparing continuously shot images without changing the color tone. Moreover, in the case where the photometric data has to be fixed by retracting the mirror, there is a problem that the differences between images are more noticeable when comparing continuously shot images when only the color balance changes while the brightness level condition is constant. According to the embodiment of the invention, there is no such problem.

By the way, if release SW2 is OFF at step S63,
Alternatively, if the high-speed continuous shooting mode is not set even if it is turned on, the process proceeds to step S65, the mirror is returned to the optical path, and the aperture is returned to the open state again.

Then, in step S66, it is detected from the state of the operation unit 10 whether or not the low speed continuous shooting is performed, and if the low speed continuous shooting is performed, the light metering and white balance are performed again from step S524.

If it is not the low-speed continuous shooting, the process proceeds to step S67 to stop the disk motor and terminate the program. In this way, in the case of low-speed continuous shooting, metering and white balance are repeated for each frame.In the low-speed continuous shooting mode, the optical finder is also functioning, which is more effective than shooting for continuous continuous shooting. This is because there are many purposes to prevent mistakes and to capture subtle changes in the subject, so it is desirable to have accurate exposure and white balance for each frame.

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 the embodiment, the light metering and white balance adjustment are performed from the beginning in steps S502 and S503 because if the release button is pressed all at once, the light metering and white balance adjustment are not performed.
This is to prevent this because the process goes to S58, and the white balance routine is step S5.
This is to prevent this because there is a possibility that a stable value may not be obtained because it is only once for 50 msec at 81.

As described above, according to the present embodiment, it is possible to immediately shift from the image pickup / recording trigger to the image pickup / recording operation without using the interrupt function, and it is possible to reduce the release time lag.

Further, according to the present embodiment, the state of the incident light incident on the image pickup element is set to the initial state (the state where the mirror enters the image pickup optical axis and the photographing light flux is guided to the optical finder and the photometric device 19 and the diaphragm is open, Also, if you have an AF mechanism, from the first lens focus position, etc., to a predetermined state (this is a mirror retracted state that is fixed in advance and the aperture value state calculated by calculation, if you have an AF mechanism the focus is The white balance adjustment is performed while controlling until it is in the correct state, etc., so high-accuracy white balance control can be performed in a short time without increasing the time lag from triggering the start of image recording to the end of actual recording. Also, it becomes possible to control incident light such as exposure and AF. The means for controlling the incident light may include a shutter, etc. in addition to the diaphragm, the mirror, and the AF.

Further, since the white balance control based on the latest color measurement information can be performed immediately before the exposure by the shutter, it is possible to sufficiently follow the change of the light source and perform the white balance control with high accuracy.

Also, even if the release button is pushed all at once, accurate white balance control can be performed, and there is no particular release time lag. Moreover, it can be easily realized by software. Further, the software itself has no time until the state of the incident light is changed from the initial state to the instructed state by the driving means, so that the software is not burdened at all.

Although the above description has been given with reference to the embodiment of the electronic camera, it goes without saying that it has a great effect when used in a camera using a silver salt film, for example.

〔effect〕

As described above, according to the present invention, the image pickup and the recording can be started without using the interrupt processing, so that the program is simplified,
The memory capacity is also small, and moreover, it is possible to move to image capturing and recording as smoothly as interrupt processing.

[Brief description of drawings]

FIG. 1 is a configuration example diagram of an image pickup device 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. Is a flow chart showing an example of a program of the image pickup apparatus of the present invention, and FIGS. 5 (a) to 5 (e) are diagrams showing details of a main part of the flow chart shown in FIG. 10 …… Continuous shooting mode switching operation part, 11 …… Color temperature detection window, 16
...... Color temperature sensor.

Claims (1)

[Claims] 1. A measuring means (19, 116) for measuring the brightness or color temperature state of a subject, a first trigger means (SW1), a second trigger means (SW2), and a subject image. An image pickup apparatus comprising: a recording means (16), wherein a first detection step (S51) of detecting an operation of the first trigger means, and a first detection step of the first trigger means by the first detection step. A measuring step (S206, S208) of measuring the brightness or color temperature state of the object by the measuring means after the operation is detected, and a second detecting step of detecting the operation of the second trigger means after the measuring step is completed. The method includes a step (S56) and a recording step (S62) of recording a subject image after the operation of the second trigger means is detected by the second detecting step, and the first detecting step causes the first image to be recorded. 1 Having a third detection step (S200, S205, S207) for detecting whether or not the second trigger means has been operated after the operation of the trigger means has been detected and before proceeding to the measuring step. ,
When the operation of the second trigger means is not detected in the third detection step, the process proceeds to the measurement step, and when the operation of the second trigger means is detected in the third detection step Is a control unit that shifts to the second detection step without passing through the measurement step.