JPH0686153A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To provide the solid-state image pickup device which precisely controls the exposure and has a simple constitution. CONSTITUTION:An aperture adjusting mechanism 2 having plural apertures F2.8, F5.6, and F11 whose sizes are limited and a solid-state image pickup element 6 having an electronic shutter function to adjust the quantity of stored electric charge constitute an exposure adjusting mechanism, and the classification of the aperture placed in the optical path, through which light from an object is supplied to the solid-state image pickup element 6, and the quantity of stored electric charge due to an electronic shutter are changed in accordance with light quantity information, thereby not only simplifying the constitution of the exposure adjusting mechanism but also precisely controlling the exposure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid-state image pickup device,
In particular, it is suitable for use in an exposure control system of an electronic still camera having an electronic shutter function.

[0002]

2. Description of the Related Art As is well known, there is known an electronic still camera which captures a still image and records it on a recording medium. The image photographed by the electronic still camera can be read out from the recording medium and displayed on a display device or printed out as necessary. A solid-state imaging device having an electronic shutter function has been conventionally used for an electronic still camera having such a function.

A conventional solid-state image pickup device is generally shown in FIG.
The block diagram of FIG. That is,
As shown in FIG. 4, a diaphragm device 20 and a shutter device 21 are provided in a light introducing path that gives light from a subject introduced through the lens 18 to the solid-state sensor 23. Then, the exposure amount of the subject is measured by the AE sensor 19,
The exposure information 19a is supplied to the microcomputer 22.

The microcomputer 22 calculates the aperture value and shutter speed based on the given exposure information 19a,
The operation of the aperture device 20 and the operation of the shutter device 21 are controlled so that an appropriate aperture value and shutter speed can be obtained. As a result, light from the subject is properly given to the solid-state sensor 23, and good image information can be obtained from the solid-state sensor 23.

The image information obtained from the solid-state sensor 23 is then given to a signal processing circuit 24 and subjected to predetermined signal processing to produce a recording signal. Then, this recording signal is given to the recording circuit 25, and is recorded on a recording medium (not shown) by the action of the recording circuit 25.

[0006]

In the case of the conventional solid-state image pickup device configured as described above, the structure of the exposure amount adjusting mechanism of the diaphragm device 20 and the shutter device 21 is complicated, so that it is expensive to manufacture them. However, there is a problem in that it requires a lot of time and labor for adjustment and the like.

Further, since the diaphragm device 20 and the shutter device 21 are complicated in structure, it is difficult to manufacture the solid-state image pickup device at low cost and to obtain stable operation. The present invention has been made in view of the above problems, and an object of the present invention is to provide a solid-state imaging device capable of accurately performing exposure amount control and having a simple configuration.

[0008]

SUMMARY OF THE INVENTION A solid-state image pickup device according to the present invention comprises an aperture adjusting mechanism having a plurality of apertures of a limited size, and an electronic device for adjusting the amount of accumulated charge. A solid-state image pickup device having a shutter function is provided, and the position of the aperture hole and the accumulated charge amount are controlled according to the light amount information to obtain an appropriate exposure amount.

[0009]

[Operation] By combining an aperture adjustment mechanism with limited types of aperture holes with an electronic shutter, the exposure adjustment mechanism can be easily constructed, and moreover, accurate exposure adjustment can be performed. Becomes

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the solid-state image pickup device of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of the solid-state imaging device of the present invention. As is apparent from FIG. 1, in the solid-state imaging device of the present embodiment, a turret diaphragm device 2 is provided between the lens 1 and the solid-state sensor 6.

As shown in the plan view of FIG. 2, the turret diaphragm device 2 has a plurality of diaphragm holes F2.8, F5.6, F.
It has a turret diaphragm 11 in which 11 is formed. Then, one of the aperture holes F2.8, F5.6, and F11 having a desired size is selected from among the aperture holes F2.8, F5.6, and F11, and the light from the subject introduced through the lens 1 is solidified. The sensor 6 is positioned in the light introduction path.

In this embodiment, the exposure amount of the subject is A
The exposure information 3a measured by the E sensor 3 is supplied to the microcomputer 4. The microcomputer 4 receives the given exposure information 3a
The turret diaphragm device 2 is controlled by calculating the aperture value and the shutter speed based on

Further, the calculated speed information is derived to the electronic shutter control circuit 5 to control the light receiving operation of the solid-state sensor 6. As a result, light from the subject is properly given to the solid-state sensor 6, and when the shutter button 10a of the shutter button device 10 is pressed, an image is taken and a good image in which the exposure amount is properly controlled is taken. Information is output from the solid-state sensor 6.

The image information obtained from the solid-state sensor 6 is then given to the signal processing circuit 7 and subjected to predetermined signal processing to produce a recording signal. Then, next, this recording signal is given to the recording circuit 8 and recorded on the recording medium 9 such as a floppy disk by the action of the recording circuit 8.

Next, the operation of the solid-state image pickup device of this embodiment having the above structure will be described. First, when the shutter button 10a is pressed, the photometric circuit is turned on at the first stroke position a, and the AE sensor 3 detects the brightness of the subject. Then, the exposure information 3 derived from the AE sensor 3
Upon receiving a, the microcomputer 4 calculates an appropriate exposure amount.

The calculation of the exposure amount is generally performed by an appropriate aperture value and shutter according to a program table provided in a ROM (not shown) built in the microcomputer 4 as shown in the characteristic diagram of FIG. Expressed in the form of speed value. Next, when the shutter button 10a is pressed to the second stroke position b, the turret diaphragm 11 shown in FIG. 2 is rotated about its center hole 11a with respect to the diaphragm value obtained by the calculation of the microcomputer 4, One of the narrowed holes F2.8, F5.6, and F11 is selected and positioned in the lens light introduction path.

Next, the actual exposure is started based on the shutter speed value given to the electronic shutter control circuit 5. At the same time, the signal processing circuit 7 performs white balance, aperture processing and the like to generate a recording signal. Then, the recording signal is given to the recording circuit 8 to be recorded on the recording medium 9. In this embodiment, since the subject image is photographed and recorded in this way, no mechanical shutter operation is required.

In the above embodiment, the AE sensor 3 is used to obtain the exposure information, but a method using a solid-state image sensor (so-called TTL photometry) may be used. Although the operation itself of the electronic shutter has not been described in detail, any type of electronic shutter may be used as long as the exposure amount can be changed. For example, a CCD element using a substrate sweeping method, an XY address type element such as a MOS type element using a preceding pixel reset pulse, or the like can be used.

[0019]

As described above, the present invention provides a diaphragm adjusting mechanism having a plurality of diaphragm holes of limited size, and a solid-state image pickup device having an electronic shutter function capable of adjusting the amount of accumulated charges. The exposure amount adjusting mechanism is configured with the type of aperture hole that is positioned in the optical path that supplies light from the subject to the image sensor, and the amount of accumulated charge is changed by the electronic shutter according to the light amount information to obtain an appropriate exposure amount. Therefore, the structure of the solid-state imaging device can be simplified and the exposure amount can be accurately controlled. As a result, it is possible to provide an electronic still camera in which the exposure amount can be accurately controlled and which has a simple structure.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a solid-state imaging device of the present invention.

FIG. 2 is a plan view showing an example of a turret diaphragm.

FIG. 3 is a characteristic diagram showing an example of exposure control showing a relationship between a shutter speed and an aperture value.

FIG. 4 is a block diagram showing an embodiment of a conventional solid-state imaging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 lens 2 turret diaphragm device 3 AE sensor 4 microcomputer 5 electronic shutter control circuit 6 solid state sensor 7 signal processing circuit 8 recording circuit 9 recording medium 10 shutter button device 10a shutter button 11 turret diaphragm a first stroke position b second stroke position

Claims (1)

[Claims] 1. A diaphragm adjusting mechanism having a plurality of diaphragm holes each having a limited size, and a solid-state image sensor having an electronic shutter function for adjusting an accumulated charge amount. A solid-state imaging device, wherein the position of the aperture hole and the amount of accumulated charge are controlled according to light amount information to obtain an appropriate exposure amount.