JPS62272770A - Image pickup device - Google Patents

Abstract

PURPOSE:To quickly pick up an image without using interruption processing by providing a discrimination step in the program of preparation steps, and shifting the operation to an image pickup action while abbreviating the following preparation steps, when a trigger pulse is generated by a triggering means. CONSTITUTION:In the AE, AWB routine to execute an automatic exposure control and auto white balance, whether a switch SW2 which is a shutter release trigger is turned on and a flag Fi equals '1' or not (i.e., image picking-up and recording are triggered and the recording is able or not) is checked by a step S200. If the step S200 shows YES, the steps S201, S204 are skipped. Therefore, without waiting for the end of the sequence, the operation can be shifted to an image pickup sequence in an extremely short time. Further, the operation can be immediately shifted to the image pickup action after the image pickup and the recording are triggered without using the interruption function. As a result, a release time lag can be decreased.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an imaging device that can quickly and silently perform image capturing and recording operations without using interrupt processing.

[Prior art]

Conventionally, when controlling the sequence of a camera system using a microprocessor (hereinafter abbreviated as CPU), the CPU
The interrupt function was utilized. That is, when SW1 is turned on by pressing the shutter halfway, the CPU performs checks of the disk drive and lens, photometry, automatic exposure calculations, display in the viewfinder, etc. Photometry at this time,
The results of automatic exposure calculations, etc. are stored in the memory area of the - placement board, and after prohibiting interruptions, they are transferred from the temporary memory area to the real memory area. Thereafter, the operation of enabling interrupts again and confirming that SWl is pressed is repeated.

While in this loop, when SW2, which is the shirt release trigger, is pressed and an interrupt occurs, the CPU enters the interrupt routine, starts the release sequence, and performs photographing based on the information in the true storage area.

[Problem that the invention seeks to solve]

However, with this method, if, for example, the aperture value of the lens changes due to zoom operation during the loop, or if an interrupt occurs before metering is complete, the camera jumps directly to the interrupt routine and takes a picture, making it impossible to obtain the correct exposure. There was a case.

There is a problem that the above-mentioned temporary memory and real memory are required for interrupt processing, and the memory capacity is twice as much as when not using interrupts.Additionally, there is a disadvantage that the program becomes more complicated due to interrupt processing. .

On the other hand, if you do not use the interrupt function, you will not be able to proceed to the shooting sequence until various data such as photometry data, lens data, etc. There was a drawback that there was.

[Means for solving problems]

The present invention provides an imaging means for capturing an optical image in an imaging device;
A trigger means for starting imaging by the imaging means, a preparation step for preparing for imaging prior to the start of imaging by the trigger means, and a preparation step after responding to the trigger means during this preparation step is omitted. , a control means having a determination step for starting imaging.

[Effect]

Since the control means has a preparation step for preparing for imaging (for example, photometry, white balance adjustment, etc.) prior to the start of imaging by the trigger means, imaging can always be performed under correct exposure and setting conditions. Further, since a determination step is provided in the preparation step, when a trigger signal is generated by the trigger means, the subsequent preparation step is omitted and the image pickup operation is started. Therefore, imaging can be quickly executed without using an interrupt.

〔Example〕

Figure 1 shows the configuration of the imaging device of the present invention, in which 1 is the body, 2 is the lens barrel, 3 is the diaphragm, 4 is the quick return mirror, 5 is the shutter unit, 6 is the image sensor, and 7 is the display. LCD, 8 is a 2-stroke release switch,
9 is a magnetic disk drive unit, 10 is a snapshot mode switching operation section, and 11 is a sensor window for detecting color temperature.

FIG. 2 is a diagram showing an example of the circuit configuration of the imaging device of the present invention, in which 12 is an aperture drive device, 13 is a mirror drive device, 14 is a shutter drive device, and 15 is a signal processing circuit for processing the output of the image sensor 6. , 16 is a recording device. Further, 116 is a color temperature sensor that detects the color temperature of the light incident through the sensor window 11, and 19 is a color temperature sensor that receives part of the light guided to the finder optical system (not shown) via the quick return mirror 4 to detect the subject. This is a photometric device for measuring brightness.

Reference numeral 17 is a control circuit which includes a microcomputer. 18 is a disk motor control circuit for controlling the rotation of the magnetic disk in the recording device.

Additionally, the release switch 8 includes a switch SWI that is turned on during the first stroke, and a switch S that is turned on during the second stroke.
Including W2.

The quick-shot mode switching operation unit 10 has three modes: single-shot S, low-speed (2 frames/second) L, and high-speed (10 frames/second) H, and can be selectively switched to one mode. It is configured.

Next, FIG. 3 shows a contingency of the main structure of FIG. 2.

First, in the signal processing circuit 15, 20a to 20c are sample and hold circuits that are controlled by sample and hold pulses that are shifted by 120 degrees from each other. Furthermore, on the front of the image sensor are R, G,
H stripe filters are pasted together in the vertical scanning direction, and the width of each stripe filter corresponds to the width of each pixel. Therefore, the horizontal line signal of the image sensor 6 is R,
Since it consists of G and B point sequential signals, the R, G and H signals are separated by the sample and hold circuits 20a to 20c, respectively.

The luminance signal Y is formed by LPFs 21a to 21c having a cutoff characteristic of 0.5MHz, and LPF 23 having a cutoff characteristic of 3MHz. 22a and 22b are gain control amplifiers provided for the R channel and B channel, and 27 is a matrix from Y, R, G, B to Y,
Forms R-Y and B-Y signals. Reference numeral 28 forms a multiplexed color video signal using an encoder, and this signal is recorded on a disk 30 via a head 29, one field per track. A disk motor 31 rotates at 3600 rpm and generates 15 periodic FG pulses at equal intervals per rotation.

Reference numeral 32 forms ambient light (light source light) with a white diffuser plate fitted into a window provided in the camera body. 33.34
are the R filter and B filter, respectively, and the photodetector is 35.36.
Red light and blue light are respectively incident on the rays. 37 and 38 are logarithmic amplifiers that amplify and logarithmically compress the outputs IR and IB of the light receiving elements 35 and 36, respectively, to form standing ogIR and viewing OgIB.

39 is a subtracter, which forms the sentence ogIR-the sentence ogR IB=the sentence ogD1. IR/IB corresponds to color temperature, and 40 converts this JLog (IR/IB) to A/
An A/D converter performs D conversion, and the color temperature signal passed through this converter is input to the control circuit 17. Further, the converter 40 samples the output of the subtracter 39 using 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 IR/IB increases, the color temperature decreases, so the gain of the gain control amplifier 22a is lowered, and conversely, the gain of the gain control amplifier 22b is increased.

Next, FIG. 4 is a flowchart showing an example of a control sequence by the control circuit 17. Further, FIGS. 5(a) to 5(e) are diagrams showing examples of each subroutine.

The program starts in step S50, and first in step S501 information on the lens 2 side (for example, aperture value,
Then, in step 35024' photometry is performed, and in step 5503, white balance is performed.

That is, in the photometry step, the light entering through the aperture 3 and the mirror 4 is received by a light receiving element (not shown) and integrated, thereby detecting the subject brightness level By, and calculating it with the preset shutter speed Tv. The aperture value is determined by the algorithm Av=By-Tv. In addition, in the white balance routine, first step 55 is performed as shown in FIG. 5(d).
41, the control circuit 17 is activated at each timing of the FG pulse.
The digital value of the color temperature information input to the
Integrate by c.

Further, in step 5542, this integral value CA is stored in a memory MA (not shown) in the control circuit.

Further, in step 5543, the data in the memory MA and the data in the memory MB, which will be described later, are added to form color temperature data CO for 50 m5ec, and the amplifier 22a is generated based on this data CO.

Controls the gain of 22b.

Next, in step 5544, the sample value for 25 m5ec is again integrated, and this integrated value CB is newly stored in the memory MB (step 3545).

Next, the data in the memory MA and the updated memory M
By adding the data of B, a new 50ms e c is obtained which is shifted by about 25m5ec from the data Co at step 5543.
form color temperature data Co, and control the gains of the amplifiers 22a and 22b based on this data Co (
step 3546).

Now, here the color temperature data CO is 50m in total.
The reason why the integral value of 5ec is used is because of flicker caused by fluorescent lights.
This is to remove.

In other words, the commercial power frequency in Japan is 50Hz or 60H.
z, and the flicker of a fluorescent lamp has twice this frequency in terms of energy.

Also, since the color temperature changes at the above frequency according to this flicker, the color temperature will fluctuate unless the color temperature data for at least one cycle of flicker is integrated, and the integration time will not be long. and white balance responsiveness deteriorates.

Therefore, 1OOHz and 12 which are twice 50Hz and 60Hz
To integrate the light from a 0Hz flicker light source, if the commercial power frequency is 50Hz, an integration of 1 second is required, and if the commercial power frequency is 60Hz, -1 sec of integration is required.
-s e c is required. Therefore, 50 m5ec, which is the least common multiple of both, becomes the shortest integration time that can eliminate the flicker of the image commercial power supply.

Furthermore, in this embodiment, the amplifiers 22a and 22 are connected every 50m5ec.
If the gain of b is controlled, the responsiveness of the white balance is poor, so the gain control is performed while taking in new color temperature data every 25 m5ec.

Now, when the white balance routine 5503 is finished, in step 351, the camera waits until the release switch SWI is turned on. When turned ON, the disk motor 31 is started in step S52, and in step 5521 it is determined whether the rotation has stabilized based on the known FG and PG multiplication signals from the motor control circuit. If it is stable, set flag F1 to 1 in step 5522, and if it is not stable, flag F1 is set.
as O. Thereafter, the AE and AWB routines are performed in step 5524. This routine uses automatic exposure control,
An example of a routine for automatic white balance is shown in FIGS. 5(a) to 5(c).

That is, step 5200 in the AE, AWB routine
In step 520, it is checked whether the release switch SW2 is ON and the flag F1 is 1 (that is, whether the trigger for imaging and recording has been made and recording is possible), and if not, step 520
Step 1 reads the lens information. This is to perform exposure calculations and white balance using the latest data.

Thereafter, the process proceeds to a photometry routine 5202, an auto white balance (AWB) routine 5203, and further proceeds to an AE calculation step 5204.

In this AE calculation step 5204, the AV value determined based on the photometric data is corrected with the latest data of the lens read in step 3201. If YES in step 5200,
In this case, steps 5201 to 5204 are skipped.

Therefore, it is possible to shift to the photographing sequence described later in an extremely short time without having to wait until all sequences are completed.

Also, in the photometry routine 3202 in FIG. 5(a), the fifth
This routine 5202 is configured as shown in Figure (b).
There is also step 3205, which is the same as step 5200, and N.

If so, the photometry is performed slowly in photometry step 5206, but if YES, the photometry is not performed and the process immediately proceeds to the next step 5206.
Proceed to 03.

The same applies to the auto white balance routine 5203 as shown in FIG. 5(C), and step 3200.
When the determination in step 5207, which is the same as in step 3205, is YES, the white balance (WB) routine 5208 is not executed and the process proceeds to the display routine 5525.

Further, the white balance step 3208 is arranged as shown in FIG. 5(d) as described above.

Also, in the display routine 5525, the same determination as 3200, 5205 and 5207 is made in step 5209 as shown in FIG.

Now, when the display routine 5525 ends, step S55
It is detected whether the release switch SW1 is on or not, and if it is off, the process jumps to step S67 to stop the disc motor and terminate the program.

Further, if the release switch SWl is turned on in step S55, the release switch SW2 is turned on in step 356.
It is detected whether or not L and the flag F1 is set to 1, that is, whether the trigger for imaging and recording has been made and whether or not recording is possible.

If it is ON, the process returns to step 5524 and repeats photometry, white balance adjustment, display, etc.

Step S56.5200.5205.5207.52
When the release switch SW2 is ON and F1 is 1 in Step 09, the imaging and recording sequence starts, and in Step S57, the mirror drive device 13 retracts the mirror from the photographing optical path, and the aperture drive device 14 opens the aperture to step 5502 or The aperture value is narrowed down to the aperture value Av determined based on the photometric data obtained in step 5206 and a predetermined shutter speed.

Then, in step 8581, the white balance routine is executed again. This routine is the same as that shown in steps 5541-3546 in FIG. 5(d) above.

Since the time from the start of execution of the mirror-up operation and the narrowing-down operation in steps S57 and 358 to the completion of the mirror-up operation and narrowing-down operation is about 60 m5ec, the white balance operation can be sufficiently performed during this time.

Further, shortly after the white balance routine in step 5581 is completed, when a sensor (not shown) detects completion of mirror up and completion of narrowing down, the process proceeds to step S60.

In this step, the shutter is opened by the shutter driving device 14, and after the shutter time Tv has elapsed, the shutter is closed in step S61. Further step 362
After recording the output of the image sensor on the disk, step 5
At 621, the head 29 is shifted to the next empty track on the disk.

After that, the release switch SW2 is turned on in step S63.
It is checked again whether or not L and flag F1=1, and if YES, then in step S64, it is read from the operation unit 10 whether or not it is high-speed continuous shooting mode, and if it is high-speed continuous shooting mode, the process goes to step S60. Then, the imaging and recording operations of opening and closing the next shutter and shifting to an empty recording track 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, the color balance conditions will not be distorted when comparing consecutively shot images without any change in hue. Moreover, in the case of a configuration in which the photometric data must be fixed by retracting the mirror, there is a problem that if only the color balance changes even though the moderation level condition is constant, the difference in the images taken consecutively - the image returned to Kyoto will be noticeable. According to embodiments of the invention, such problems do not exist.

Now, if the release SW2 is OFF in step S63, or if it is not in high-speed snapshot mode even if it is ON, the process advances to step S65, and the mirror is returned to the optical path.
Return the aperture to open.

To the north, in step S6B, the operation unit 10 determines whether or not low-speed photography is to be performed.
If the state is low-speed photography, step 55 is performed again.
From 24, perform photometry and white balance.

If it is not low-speed photography, the process advances to step S67 to stop the disk motor and end the program. The reason for repeating metering and white balance for each frame in slow-speed shooting is that the optical viewfinder also functions in slow-speed shooting mode, and the purpose of this is to avoid mistakes in shooting rather than taking continuous separated photos. This is because the purpose is often to capture a momentary moment of subtle change in the subject, so it is desirable that the exposure and white balance be accurate frame by frame.

In addition, in the embodiment 1-1 below, the output of the color temperature sensor is sampled at the timing of the FG pulse for white balance and A/D converted, so a special sampling pulse is sent to the synchronous signal generator for sampling. It is not necessary to create a program using a program, etc., and there is also an effect that it is easy to synchronize the speed control of the motor by the control circuit and the white balance control described above using a program.

In addition, in the embodiment, the reason why photometry and white balance adjustment are performed from the beginning in steps 5502 and 5503 is because if the release button is pressed all at once, the process will proceed to the stop-down in step 358 without performing photometry.
This is to prevent this, and since the white balance routine is performed only once (50m5 e c in step 3581), there is a possibility that a stable value cannot be obtained.

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

Furthermore, according to the present embodiment, the state of the incident light entering the image sensor is set to the initial state (the mirror enters the imaging optical axis, guides the imaging light flux to the optical viewfinder and the photometer 19, and the aperture is opened), In addition, if it has an AF mechanism, it will change from the initial lens focus position, etc.) to a predetermined state (this is a pre-fixed mirror retracted state and an aperture value state determined by calculation, and if it has an AF@ structure, - Since the white balance is adjusted during the control until the camera is in focus, etc., there is no increase in the time lag between triggering the start of image capturing and recording and actually finishing recording, and high-precision white is achieved in a short time. Balance control and incident light control such as exposure and AF become possible. Note that the means for controlling the incident light may include a shutter, etc. in addition to an aperture, a mirror, and AF.

Furthermore, since white balance control can be performed based on the latest colorimetric information immediately before exposure by the shutter, it is possible to sufficiently follow changes in the light source and to perform highly accurate white balance control.

Furthermore, even when the release button is pressed all at once, accurate white balance control is possible, and there is no particular release time lag. Moreover, it can be easily realized using software. Further, since the software itself is idle until the state of the incident light is changed from the initial state to the instructed state by the driving means, no burden is placed on the software.

It should be noted that although the above description has been made with reference to an example of an electronic camera, it goes without saying that great effects can also be obtained when used in a camera using a silver halide film, for example.

〔effect〕

As described above, according to the present invention, imaging and recording can be started without using interrupt processing, which simplifies programming.
It requires less memory capacity, and can transition to imaging and recording as smoothly as interrupt processing.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an imaging device according to the present invention, FIG. 2 is a diagram showing an example of the circuit of the configuration shown in the first diagram, FIG. 3 is a diagram showing the main part configuration of the circuit configuration shown in the second diagram, and FIG. 5 is a flowchart showing an example of a program for the imaging apparatus of the present invention, and FIGS. 5(a) to 5(e) are diagrams showing details of main parts of the flowchart shown in the fourth figure. i o------ Continuous shooting mode switching operation section, 11---
--One color temperature detection window, 16--color temperature sensor.

Claims (1)

[Scope of Claims] It comprises: an imaging means for taking an optical image; a trigger means for starting imaging by the imaging means; a preparation step for preparing for imaging prior to the start of imaging by the trigger means; and during this preparation step, the above-mentioned An imaging apparatus comprising: a control means having a determination step for starting imaging in response to a trigger means, omitting subsequent preparation steps.