JP2002010136A - Imaging device - Google Patents

Abstract

(57) [Problem] To provide an image pickup apparatus having an automatic exposure mode suitable for a case where a change in an exposure environment at the time of photographing changes. An image pickup device, an exposure changing means (for example, an electronic shutter function of a CCD, an aperture in an optical block, or an AGC) for changing an exposure level, and a control circuit for controlling the exposure changing means are provided. . The control circuit 9
It has an automatic control mode in which the exposure level is detected from, for example, the output of the DSP 6 and the exposure changing means is controlled in accordance with the detection result, and the detection and control are repeated at a predetermined cycle until the detection result enters an appropriate range. When entering the range for the first time, release the automatic control mode and stop the automatic control of the exposure level. Further, a switch SW1 for switching between the automatic control mode and the normal automatic control mode and a forcible release switch SW2 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video camera having a mode for automatically controlling the exposure level of an image sensor, for example, in which the exposure level fluctuates unstablely due to a large difference in the reflectance between the subject and the background. The present invention relates to an imaging apparatus having a function of canceling an automatic control mode when an exposure level falls within an appropriate range in order to prevent the occurrence of such a situation.

[0002]

2. Description of the Related Art In a video camera, when a subject is photographed, the exposure level of an image changes depending on the difference in reflectance between the subject and the background and the position and intensity of a light source. In order to obtain a clear and clear image, it is necessary to correct the exposure level of the image sensor according to these exposure environment conditions. Therefore, many video cameras have an automatic exposure mode for automatically correcting the exposure level of an image, and the exposure correction can be switched from manual to automatic by switching of a photographer.

In the automatic exposure mode, for example, an exposure level of a video signal is detected inside a video camera, and an exposure level of a CCD or an aperture is feedback-controlled in accordance with the detection result, and the detection and control are repeated at predetermined time intervals. It is carried out.

[0004]

However, in the conventional video camera, for example, when the subject is mounted on a microscope and the subject is photographed in the automatic exposure mode, the reflectance between the sample (preparation) as the subject and the background (object glass) is measured. , The exposure state of the captured image may constantly fluctuate while searching for the subject. Further, even after the object to be photographed is within the field of view of the camera and the movement of the sample with respect to the camera is stopped, for example, when the object moves like a microorganism, the exposure environment condition always changes.
For this reason, if the automatic exposure mode is maintained, the exposure state of the captured image fluctuates finely at all times, resulting in an unsettling image.

Therefore, in such a case, the photographer
After the subject to be shot was within the field of view of the camera, the exposure mode was switched from manual to automatic, and automatic exposure compensation was performed. After this compensation was completed, the exposure mode was switched from automatic to manual again. .

An object of the present invention is to newly provide an image pickup apparatus having an automatic exposure mode suitable for a case where a change in the exposure environment at the time of photographing changes.

[0007]

According to a first aspect of the present invention, there is provided an image pickup apparatus comprising: an image pickup device; an exposure change unit for changing an exposure level of the image pickup device; and a control circuit for controlling the exposure change unit. The control circuit detects the exposure level of the image sensor, controls the exposure changing means according to the detection result, and repeats the detection and control at a predetermined cycle until the detection result enters an appropriate range. The automatic control mode is released when the detection result first enters the appropriate range, and the automatic control of the exposure level is stopped. The imaging apparatus of the present invention preferably further includes a manual operation unit that is manually operated, and the control circuit is configured to output the manual operation unit after canceling the automatic control mode and to manually output the exposure change unit. An operation signal used for control is received.

Alternatively, the control circuit includes a first automatic control mode that is released when the detection result first enters the proper range, and a predetermined period for causing the detection result to enter the proper range. And a second automatic control mode in which the mode is not released until forced.
A mode switch for switching between the first and second automatic control modes when operated is further provided. In this case, it is preferable that the control circuit further includes a manual operation means that is manually operated, and a forcible release switch for forcibly releasing the first and second automatic control modes when operated. After the first and second automatic control modes are released, an operation signal output from the manual operation means and used for manual control of the exposure changing means is received.

The exposure changing means is a pulse generating circuit for generating a pulse for changing the maximum exposure amount of the image sensor and supplying the pulse to the image sensor, or a diaphragm for changing the amount of light incident on the image sensor.

An image pickup apparatus according to a second aspect of the present invention includes an image pickup element for picking up an image and outputting an image pickup signal, a first changing means for changing an exposure level of the image pickup element, and an image pickup signal from the image pickup element. A control circuit for controlling the first and second change means, the control circuit detecting an exposure level of the image pickup device, and detecting the exposure level of the image sensor according to a detection result; , An automatic control mode for controlling at least one of the second changing means and repeating the above detection and the above control until the detection result enters the proper range. Cancel the automatic control mode.

Preferably, an automatic gain control circuit is provided as the second changing means, and a signal processing circuit for performing predetermined signal processing on the signal after gain control is connected to an output of the automatic gain control circuit. The control circuit detects a signal from the signal processing circuit and determines a feedback control amount to the automatic gain control circuit.

According to the imaging apparatus of the present invention having the above-described configuration, when the forcible release switch is not operated, the exposure control mode of the control circuit is changed to the second mode in response to, for example, the operation of the mode changeover switch. One of the first automatic control mode and the second automatic control mode is selected. In these automatic control modes, the control circuit detects the exposure level of the image sensor by monitoring an image signal or the like, and controls the electronic shutter value of the image sensor and the image sensor so that the detected exposure level falls within an appropriate range. The input light amount or the gain of the captured image is controlled. When changing the electronic shutter value of the image pickup device, the control circuit controls the pulse generation circuit to change the pulse width or the like supplied to the image pickup device and changing the maximum exposure amount. When changing the amount of light incident on the image sensor, the control circuit controls the aperture. further,
When changing the gain of the captured image, the control circuit adjusts the feedback control amount of the automatic gain control circuit. And
In either case, until the detection result falls within the appropriate range,
This detection and control are repeated.

In the second automatic control mode, as in the case of the normal automatic exposure control, even if the detection result falls within the proper range, the detection and control are repeated as many times as the next cycle comes, unless forcedly terminated. On the other hand, in the first automatic control mode,
When the detection result first enters the appropriate range, the mode is released, and for example, the mode is forcibly shifted to the manual control mode. Further, in any of the first and second automatic control modes, when the forcible release switch is operated, the exposure control mode of the control circuit is forcibly shifted to the manual control mode.

[0014]

FIG. 1 is a block diagram showing a schematic configuration of a camera system including an imaging device according to the present invention. This camera system is roughly divided into an imaging device 1 such as a digital video camera and an image display processing device 40.
Consists of The imaging device 1 and the image display processing device 40
It has connectors 1a and 40a compliant with the serial interface standard of EEE1394, and is connected by a cable 50 compliant with the standard.

The image display processing device 40 has various forms according to the use of the camera system. For example,
An inspection device for inspecting an article, a monitoring device for monitoring, a drawing device, an assembling device, an image editing device, or the like, often includes a built-in monitor. Further, a monitor for simply displaying an image is provided by the image display processing device 40.
In such a case, display processing for displaying an image in various forms on a monitor is performed.

An image pickup apparatus (camera) 1 includes an optical block 2, an image pickup device such as a CCD (Charge Coupled Device) 3, an automatic gain control circuit (AGC) 4, an analog / digital converter (ADC) 5, a DSP (Digital Signal). Proc
essor) 6 and other signal processing circuits, EEPROM (Electrica
lly Erasable and Programmable Read Only Memory)
7. Timing generator (TG)
8, and a central processing unit (CPU; Central Processing Un
it) has 9.

The camera 1 has switches SW1 and SW2 that can be operated from the outside. The switch SW1 is a switch for switching the exposure control mode between a first automatic control mode and a second automatic control mode, and
The switch SW2 is a switch for forcibly canceling the automatic exposure control mode and shifting to the manual control mode.
The two automatic control modes will be described later. Note that these switches SW1 and SW2 do not necessarily need to be provided individually. For example, the switches SW1 and SW2 are configured by one push button type switch, and when pressed once, the first automatic control mode is performed. Alternatively, a configuration may be adopted in which the mode is switched to the manual control mode at the third time, and then returned to the first automatic control mode again when pressed.

The camera 1 is a 1394 Cam-Lin as a control integrated circuit conforming to the IEEE 1394 standard.
Link layer IC10, 1394PHY named k
, And a driving IC 30 called an RS232C driver that supports the RS232C general-purpose interface standard. Note that there is no limitation on the serial interface standard of the camera according to the present invention, and an IC
Either 10, 20 or the IC 30 may be provided. Instead of these ICs, other standards, such as USB (U
A driving IC conforming to the standard (niversal Serial Bus) may be provided. Further, there is no need to comply with the serial interface standard, and in that case, all of the ICs 10, 20, and 30 can be omitted.

The optical block 2 is composed of an optical component group including a zoom lens combining a plurality of lenses, an optical filter, and a stop. The optical block 2 condenses incident light from the subject after limiting the amount of light with a built-in aperture, and condenses the light.
An image is formed on the light receiving surface of No. 3.

The CCD 3 has a light receiving section in which several hundred thousand to several million pixel cells each including a photodiode are arranged in a matrix. The incident light that has reached the light receiving unit is photoelectrically converted by each photodiode to generate signal charges. After the signal charges are accumulated for a certain period of time, the signal charges are sent to the transfer unit and vertically and horizontally transferred, and the analog signal is output from the output unit. Is output as a shooting signal (RGB primary color signal).

The CCD 3 has an electronic shutter function for changing the maximum amount of charge stored in a pixel cell within a unit time. As a configuration for realizing an electronic shutter, for example, a horizontal or vertical O
It includes an FD (Over Flow Drain) and an input terminal for a clock signal for controlling the OFD. A function (or correction value) that can adjust the sensitivity by changing the maximum accumulated charge amount in a pixel cell and correct the exposure level of a captured image on the CCD side, such as an electronic shutter, is hereinafter referred to as a “CCD iris”. Say In the present embodiment, “lowering the CCD iris” means 1 / x (x = 60, 100, 1000,
..), And increasing the exposure time of the electronic shutter to increase the sensitivity of the pixels, and consequently increase the exposure level of the captured image. vice versa,
“Increasing the CCD iris” means increasing the shutter value x and shortening the exposure time of the electronic shutter to lower the sensitivity of the pixel, and as a result, lowering the exposure level of the captured image.

The AGC 4 receives an image pickup signal from the CCD 3, automatically adjusts the gain according to the signal level, and removes reset noise at the time of CCD output by a built-in correlated double sampling circuit. Send to A
The DC 5 converts the input analog signal after sampling into a digital signal and supplies the digital signal to the DSP 6.

The DSP 6 responds to the digital signal supplied from the ADC 5 by a luminance signal Y and a color difference signal Cr,
Cb is generated. Here, as an example,
For example, the luminance signal Y is an 8-bit digital signal,
Assuming that each of the color difference signals Cr and Cb is a 4-bit digital signal, a digital video signal of 16 bits in total is output from the DSP 6.

The TG 8 generates, for example, various timing pulses in order to control the operation timing of the entire image pickup apparatus, and transmits the various timing pulses to the serial bus 1.
c, the respective circuits, ie, CCD3, AGC
4, the ADC 5, the DSP 6, the CPU 9, and the like.
The EEPROM 7 is connected to the serial bus 1c, and evaluates an exposure level of an image captured by the camera, and
Ancillary information necessary for video recording and reproduction, for example, information such as the date, time, and imaging conditions when the video signal was recorded is stored.

The CPU 9 controls the DSP 6 to generate the luminance signal Y and the color difference signals Cr and Cb. At this time, the CPU 9 detects the exposure level of the image based on, for example, the luminance signal Y from the DSP 6. The TG 8 is controlled in accordance with the detection result of the exposure level, whereby the pulse width of the clock signal for controlling the electronic shutter of the CCD 3 is changed, the aperture amount is adjusted, or the feedback control amount to the AGC 4 is controlled. adjust.

More specifically, a serial input / output port SIO of the CPU 9 is connected to the serial bus 1c so that a digital video signal from the DSP 6 can be input. The TG 8 is controlled based on the digital video signal from the DSP 6, thereby changing the pulse width of the clock signal for controlling the electronic shutter of the CCD 3.
The digital video signal from the DSP 6 is sent to the CPU 9
Is returned to an analog signal by a digital / analog converter incorporated in the A / D converter, and is used for a control signal output from the analog output terminal D / A to the AGC 4. That is, in the course of the digital / analog conversion, the signal level of the digital video signal from the DSP 6 is detected in the CPU 9, and according to the detection result, the AGC 4 outputs the digital video signal having the optimum signal level from the DSP 6. Is performed.

The CPU 9 adjusts the aperture in the optical block 2 as needed. Further, the CPU 9 has a link layer IC 10 connected to the parallel input / output port PIO, and the link layer IC 10
Control.

By the way, in the data transfer of the IEEE1394 serial interface, a request signal (Request),
In addition to the asynchronous transfer mode for requesting and confirming the reception of a response signal (Acknowledge), an isochronous (Isochronous) mode in which data is always sent every 125 μs from one of the connected peripheral devices called nodes.
s) There is a transfer mode. In this transfer mode, data transfer is performed together with additional data in packet units determined by the standard. In such a circuit-switching mode data transfer, a small-scale data transfer is always completed at regular intervals, and a necessary transfer speed is guaranteed. Therefore, a large buffer memory for dealing with the delay is loaded in the peripheral device. There is an advantage that there is no need.

The above-mentioned physical layer IC 20 directly drives an IEEE 1394 serial interface bus laid in the cable 50, and sends out packets to this bus and receives various types of packets transmitted. Further, under the control of the CPU 9, the link layer IC 10 controls isochronous transfer of digital video signals from the DSP 6, control of asynchronous transfer,
In addition, it controls the physical layer IC 20. Further, since the link layer IC 10 is for image transfer, it incorporates a frame memory and controls the frame memory.

Next, the operation of the exposure level adjustment processing will be described. The camera 1 according to the present embodiment has a processing mode of exposure level adjustment (corresponding to the control mode of the CPU) shown in FIG.
In Manual Exposure (ME) mode, which can accept the operation of the manual exposure adjustment knob that has been omitted,
Normal automatic exposure (hereinafter, FT (Full Time)-AE (Auto
Exposure) mode, and performs an automatic exposure (AE) process only once to forcibly shift to the ME mode.
It has a mode of T (One Time) -AE processing.

FIG. 2 is a flow chart of mode selection which is the basic of the exposure level adjustment processing. FIG. 3 shows OT
4 is a flowchart of the AE process, FIG. 4 is a flowchart of the FT-AE process, and FIGS. 5 and 6 are flowcharts of the AE process. 5 and FIG. 6 constitute one process, and A, B, and C in the respective drawings indicate connection points in both the drawings. Also,
In these figures, all the judgments are made by the CPU 9 unless otherwise mentioned.

The CPU 9 constantly monitors the input of the mode switching signal from the switches SW1 and SW2. Specifically, in step ST0 of FIG. 2, it is determined whether or not there is a mode switching operation. If there is no mode switching operation, the apparatus is in a standby state until a mode switching operation is performed. If there is a mode switching operation, the type of mode is determined in the next step ST1. Specifically, it is determined from the signal from the switch SW1 in FIG. 1 whether the mode is the first automatic control mode (first AE mode) or the second automatic control mode (second AE mode). When the switch SW2 is operated,
Regardless of the state of the switch SW1, the manual control mode (ME
Mode). In the latter case, if the automatic control mode is set before the operation of the switch SW2, the mode is forcibly released by the operation of the switch SW2.

In the case of the first AE mode, the processing flow proceeds to step ST10, and the OT-AE processing is executed. In the case of the second AE mode, the processing flow proceeds to step ST20, and the FT-AE processing is executed. In the case of the ME mode, the processing flow proceeds to step ST3, where it is determined whether or not there is an ME operation. If there is an ME operation, the ME process is performed in the next step ST30. If there is no ME operation, the determination in step ST3 is repeated until this operation is performed, and the system enters a waiting state for accepting the ME operation.

At any stage in FIG. 2, acceptance of the mode switching operation has priority. That is, each processing step S
If there is a mode switching operation in the middle of T10, ST20, ST30 or in the waiting state for accepting the ME operation, the operation is preferentially accepted and the processing flow is forcibly shifted before step ST0. In addition, even when the power is turned off and the camera is turned off, the processing flow is forcibly shifted before step ST0 at a timing such as when the switch is turned on.

In the OT-AE processing shown in FIG. 3, first, in step ST11, it is determined whether the AE processing is the first time. For example, the CPU 9 holds the number of AE processes in an internal register, and stores the contents of this register in the AE register.
It is incremented for each process and reset for each mode switching operation. In step ST11, it is determined whether or not the AE processing is the first time by referring to the contents of the register. If the AE process is the first time, the gain, C
After setting the CD iris together, the next step ST1
At 00, the AE process is performed. If the AE process is not the first time, step ST12 is skipped and the next step ST10
Go to 0.

After the AE process, it is determined in step ST13 whether the adjustment is unnecessary or the adjustment is completed. If the determination result is "No", the AE process is repeated at a predetermined cycle. Specifically, for example, the AE process is repeated each time a detection value for detecting an exposure level is input to the CPU 9 from the DSP 6 to which a video signal sent from the CCD at a predetermined cycle is input.

On the other hand, if the decision result in the step ST13 is "Yes", the OT-AE mode is canceled and the ME
After the mode is forcibly set, the OT-AE process ends.

In the FT-AE process shown in FIG. 4, after the gain and the CCD iris are both automatically set in step ST21, the AE process is performed in the next step ST100. This A
The E process is repeated, for example, each time a detection value is input from the DSP 6 without determining that adjustment is unnecessary or that adjustment has been completed. This repetition loop processing exits, for example, when there is a mode switch, when the power is off, or when the camera switch is off. In these cases, the FT-AE processing ends, and the processing flow of FIG. It returns before step ST0.

OT-AE processing and FT described above
In the AE process, the content of the AE process in step 100 is common. Hereinafter, this AE processing will be described in detail. In FIG. 5, when the AE process is started, an exposure value of a captured image is detected in step ST101, and in step ST102, the detected exposure value is compared with a reference value. Specifically, a detection value (for example, a luminance signal level) for detecting an exposure level from the DSP 6 is determined by the CPU.
9 is input to the CPU 9, for example, an EEPROM.
7 is compared with the reference value of the exposure level read out.

As a result of the comparison, if it is determined that the exposure level of the photographed image is appropriate, it is determined in step ST103 that adjustment is unnecessary (adjustment is completed after the second AE process), and the AE process ends.

On the other hand, if it is determined in step ST102 that the exposure value of the captured image is larger than the reference value or sufficiently large and the image is determined to be "bright", the processing flow proceeds to step ST104. In step ST104, it is determined whether the gain can be automatically adjusted. If "Yes", it is determined in next step ST105 whether the current gain and the next target value for decreasing the gain are within the adjustment range.
If the answer is “yes” here, step ST
At 106, the gain is reduced by a predetermined step width or according to the result of comparison with the reference value. Specifically, the gain is adjusted by the CPU 9 performing feedback control of the AGC 4 via the analog terminal D / A.
Be executed. After the gain adjustment, the AE process ends.

If the gain cannot be automatically adjusted in step ST104, the exposure level adjustment by gain adjustment is abandoned, and the processing flow proceeds to step ST107. Step ST1
At 07, it is determined whether the CCD iris can be automatically adjusted.
If “yes”, in the next step ST108, the current C
It is determined whether the target value for raising the CD iris and then the CCD iris is within the adjustment range. If “yes” here as well, in step ST109, the CCD iris is raised by a predetermined step width or according to the result of comparison with the reference value. Specifically,
The adjustment of the CCD iris is executed by the CPU 9 controlling the TG 8. For example, when the pulse width of the shutter-on clock signal output from the TG 8 to the CCD 3 is reduced, the amount of charge that can be handled by each pixel cell of the CCD decreases, and as a result, the exposure level of a captured image decreases. After the gain adjustment, the AE process ends.

Outside the gain adjustment range (step ST105)
If “No” at step ST107, the automatic adjustment of the CCD iris is impossible (“No” at step ST107), and if it is out of the adjustment range of the CCD iris (“No” at step ST108), the process proceeds to step 110. The AE process ends as “adjustment impossible”.

On the other hand, in the previous step ST102,
As a result of the comparison between the exposure value and the reference value, when it is determined that the image is “dark”, the process flow proceeds to step ST111, and the automatic adjustment of the gain is enabled / disabled as in the previous steps ST104 and ST105. ST111) and whether or not it is within the adjustment range (step ST112). Only in the case of "yes" in all cases, in step ST113, a process of increasing the gain is performed, and then the AE process ends. If "No" in step ST111, the automatic adjustment of the CCD iris is enabled / disabled (step ST111) as in the previous steps ST107 and ST108.
114) and whether it is within the adjustment range (step ST115). Step S only if both are "Yes"
At T116, a process of lowering the CCD iris is performed, and then the AE process ends. If the gain is out of the adjustment range (“No” in step ST112), CC
When the automatic adjustment of the D iris is impossible (“No” in step ST114), and when the adjustment is out of the adjustment range of the CCD iris (“No” in step ST115), the AE process is terminated as “adjustment impossible”.

As described above, in the camera 1 according to the present embodiment, in addition to the normal automatic control mode (FT-AE mode), the camera 1 is forcibly switched to the manual control mode (ME mode) after performing AE processing only once. It has an OT-AE mode for transition. For this reason, for example, when the reflectance of the subject is significantly different from that of the background, such as when shooting a slide, by switching the switch SW1 to the OT-AE mode, a stable shot image can be obtained. In addition, in order to obtain a stable captured image, the photographer does not need to bother switching operation to return to the manual control mode.
Operability is improved. In particular, in the case of continuous shooting in which the subject is changed one after another in the OT-AE mode, the effect of the improvement in the operability is extremely large.

In the above, the case where the mode changeover switches SW1 and SW2 are provided in the camera itself has been described. However, the mode changeover may be executed by a command from the image display processing device 40 side. In this case, OT-AE
Since the switching operation for returning to the manual control mode in the mode is automatically performed, the control commands can be reduced accordingly.

Various other changes are possible in the present embodiment. For example, in FIG. 3 and FIG.
Steps ST12 and ST2 for setting D iris to automatic
5 and 6 in the flowcharts of FIGS.
Steps of T107, ST111, and ST114 can be omitted. Step ST10 for asking the gain adjustment range
5, ST112 can be omitted if the image quality does not deteriorate even if the gain is excessively increased or decreased. Steps ST108 and ST115 for asking the adjustment range of the CCD iris are provided because flickering or the like may occur and the image quality may deteriorate. However, by prohibiting the adjustment to such a range in advance, these steps are performed. Can also be omitted.

After adjusting the CCD iris first,
The gain may be adjusted, or the gain may be adjusted first only when the image is dark. Further, the aperture in the optical block 2 may be adjusted instead of the CCD iris or in combination with the CCD iris. In any case, the exposure level of the image can be adjusted by adjusting the gain, the CCD iris, and the aperture independently, as well as being able to be combined with the gain. 3 and 4, in step ST12 for automatically setting the gain and the CCD iris,
In ST21, the aperture may be automatically set. Further, only one of the gain and the CCD iris can be automatically set. Further, after the automatic setting step, these manual initial setting steps may be provided.

[0049]

According to the imaging apparatus of the present invention, the (first) automatic control mode is released when the detection result first enters the appropriate range. Once the subject is within the field of view of the image sensor,
After the exposure control, the automatic control is released, and for example, a manual control mode is set. Therefore, even when the reflectance of the subject and the background is significantly different, and the exposure mode of the entire screen changes every moment due to subtle changes in the subject or the background, the exposure value of the entire screen switches so as to flicker. There is no. Although the subject itself naturally becomes brighter or darker, an overall natural and fallen image is obtained.

Further, in order to obtain such a natural and calm image, there is no need for the operator to switch to the manual control mode, and the operability is improved. In particular, when continuous shooting is performed while changing the subject one after another, the trouble of switching to the manual control mode is not required, which greatly contributes to the generation of time margin for operation. If the subject is too bright or too dark after entering the manual control mode, it can be dealt with by slowly changing the overall exposure level.

Further, when the exposure mode is switched remotely, there is an advantage that the number of control commands can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of a camera system according to an embodiment.

FIG. 2 is a basic flowchart of an exposure level adjustment process including a mode selection in the operation of the camera according to the embodiment.

FIG. 3 illustrates an operation of the camera according to the embodiment.
It is a flowchart which shows AE processing.

FIG. 4 illustrates an operation of the camera according to the embodiment.
It is a flowchart which shows AE processing.

FIG. 5 is a first flowchart of an AE process in the operation of the camera according to the embodiment.

FIG. 6 is a second flowchart of the AE process in the operation of the camera according to the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Camera (imaging device), 1a ... Connector, 1c ... Serial bus, 2 ... Optical block, 3 ... CCD (imaging element), 4 ... Automatic gain control circuit, 5 ... Analog / digital converter (ADC), 6 ... DSP (signal processing circuit), 7
... EEPROM, 8 ... Timing generator (T
G), 9 central processing unit (CPU), 10 link layer IC, 20 physical layer IC, 40 processing device,
40a: Connector, 50: Cable, SW1: Mode switch, SW2: Forced release switch.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H002 AB02 CC21 DB02 FB02 FB22 FB28 FB81 FB84 GA35 HA11 JA12 5C022 AB03 AB12 AB20 AB33 AC01 AC32 AC42 AC75 5C024 AX01 BX04 CX54 CX66 GY01 HX18 HX50 HX60

Claims (13)

[Claims] 1. An image pickup device, comprising: an exposure change unit for changing an exposure level of the image pickup device; and a control circuit for controlling the exposure change unit, wherein the control circuit detects an exposure level of the image pickup device. ,
Controlling the exposure changing means in accordance with the detection result, having an automatic control mode in which the detection and control are repeated at a predetermined cycle until the detection result enters an appropriate range, and when the detection result first enters the appropriate range. An imaging device that releases the automatic control mode and stops automatic control of the exposure level. 2. The control circuit according to claim 1, wherein the first automatic control mode is canceled when the detection result first enters the proper range, and the detection and the control are performed at a predetermined cycle for bringing the detection result into the proper range. A second automatic control mode in which the mode is not released until the operation is forcibly performed, and further comprising a mode changeover switch for switching between the first and second automatic control modes when operated. An imaging device according to any one of the preceding claims. 3. The control circuit according to claim 1, further comprising: manual operation means which is manually operated; and a forcible release switch for forcibly releasing the first and second automatic control modes when operated. 3. The image pickup apparatus according to claim 2, wherein after the second automatic control mode is released, an operation signal output from the manual operation means and used for manual control of the exposure changing means is received. 4. The apparatus according to claim 1, further comprising: manual operation means which is manually operated, wherein said control circuit outputs an operation signal output from said manual operation means after said automatic control mode is released and used for manual control of said exposure changing means. The image pickup apparatus according to claim 1, wherein the image pickup apparatus receives the request. 5. A pulse generating circuit according to claim 1, wherein said exposure changing means generates a pulse for changing a maximum exposure amount of said image sensor and supplies the pulse to said image sensor.
An imaging device according to any one of the preceding claims. 6. An image pickup apparatus according to claim 1, wherein said exposure change means is a stop for changing the amount of light incident on said image pickup device. 7. An image pickup device for picking up an image and outputting an image pickup signal; a first change unit for changing an exposure level of the image pickup device; a second change unit for changing a gain of an image pickup signal from the image pickup device; A control circuit for controlling the first and second changing means, wherein the control circuit detects an exposure level of the image sensor,
An automatic control mode for controlling at least one of the first and second changing means in accordance with the detection result and repeating the detection and the control until the detection result falls within an appropriate range; An imaging device for canceling the above-mentioned automatic control mode when entering the first time. 8. The control circuit according to claim 1, wherein the first automatic control mode is canceled when the detection result first enters the proper range, and the detection and the control are performed at a predetermined cycle for bringing the detection result into the proper range. A second automatic control mode in which the mode is not released until the operation is forcibly performed, and further comprising a mode changeover switch for switching between the first and second automatic control modes when operated. An imaging device according to any one of the preceding claims. 9. The apparatus further comprises: manual operation means which is manually operated; and a forcible release switch for forcibly releasing the first and second automatic control modes when operated. 9. The image pickup apparatus according to claim 8, wherein after canceling the second automatic control mode, an operation signal output from the manual operation means and used for manual control of the exposure changing means is received. 10. An operation signal output from the manual operation unit after the automatic control mode is canceled, the operation signal being used for manual control of the exposure change unit, further comprising a manual operation unit operated manually. The image pickup apparatus according to claim 7, wherein the image pickup apparatus receives the request. 11. A pulse generating circuit for generating a pulse for changing a maximum exposure amount of the image sensor and supplying the pulse to the image sensor.
An imaging device according to any one of the preceding claims. 12. The image pickup apparatus according to claim 7, wherein said first changing means is a stop for changing the amount of light incident on said image pickup device. 13. An automatic gain control circuit as said second changing means, wherein a signal processing circuit for performing predetermined signal processing on a signal after gain control is connected to an output of said automatic gain control circuit, The imaging apparatus according to claim 7, wherein the circuit detects a signal from the signal processing circuit and determines a feedback control amount to the automatic gain control circuit.