JPS636977A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To obtain a signal having a proper output level at the time of operating a shutter and to obtain an output signal of a proper level even at the time of an ordinary image pick up by providing a light quantity adjusting means capable of varying the transmission of light on the front surface of a solid-state image pickup element. CONSTITUTION:The solid-state image pickup element 2 perfoms an electronic shutter operation by a conventional driving method. The diaphragm of a lens 1 at this time is adjusted to a proper exposure at an exposure time during the shutter operation. In case of the ordinary image pickup, the light transmission of the light quantity adjusting means 9 is adjusted by the use of a pulse so as to obtain the signal of the proper level. Thereby, in case of both the ordinary image pickup and the shutter operating, a proper exposure condition can be obtained and the output signal of the proper level can be obtained in an ordinary television picture and a shutter picture.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solid-state imaging device having an electronic shutter function.

[Prior Art] Conventionally, this type of solid-state imaging device has been configured as shown in FIG.
2) and by using a solid-state imaging device equipped with a charge sweeping section (16) and changing the driving method of this device,
It has an electronic shutter function.

In FIG. 4, (1) is a lens, (2) is a solid-state image sensor, (3) is a drive circuit that drives the solid-state image sensor (2),
(4) is a synchronization signal generation circuit, (5) is a solid-state image sensor (2
), (8) is a field memory that stores video signals of arbitrary time, (8) is a video output terminal, and (7) is a shutter command input terminal.

In FIG. 2, (11) is an imaging section, (12) is an accumulation section that stores charges accumulated in the imaging section (11), and (12) is an accumulation section that stores charges accumulated in the imaging section (11).
13) transfers the charges accumulated in the imaging unit (11) to the storage unit (1
(14) is an accumulation section transfer register that transfers charges transferred and stored in the accumulation section (12) to the horizontal output register (!5);
5) is a horizontal output register that sequentially outputs the charges transferred by the storage section transfer register (14).

(16) is a cleaning drain serving as a charge sweeping section for discharging charges overflowing from the horizontal output register (15), and (17) is an output terminal of the solid-state image sensor (2).

Next, the operation will be explained.

In the configuration shown in FIG. 4, the solid-state image sensor (2) is driven by an electronic shutter by the drive circuit (3).

Figure 5 shows the operation timing of the above configuration, in which VD is a vertical synchronization pulse, SP is a shutter command pulse,
GP is a register control pulse that controls the imaging unit transfer register (13), storage unit transfer register (14) and horizontal output register (15), PI is an imaging unit transfer pulse,
PS is a storage section transfer pulse, T is a gate pulse, PH is a read pulse, and SL is a shutter open time.

When there is no shutter command, the vertical synchronizing pulse VD is fed back to the register control pulse GP at times t and -t2, and the imaging section transfer pulse PI and storage section transfer pulse PS are output as shown in the figure, and the imaging section ( 11) to the storage section (12). and time t2
The signal is taken into the horizontal output register (15) by the subsequent storage unit transfer pulse PS and gate pulse T, and is output from the horizontal output register (15) to the image sensor output terminal (17) by the read pulse PH. This is the operation during normal imaging.

When a shutter command pulse SP is input from the shutter command input terminal (7) at time t3, charge is transferred from the imaging section (11) to the storage section (12) between ts and t6 by the register control pulse GP at time t4. will be carried out.

Then, a register control pulse GP is generated at time t6 by the shutter command pulse SP.

Charges generated in the imaging unit (11) due to exposure between times t6 and t7 are transferred to an imaging unit transfer pulse PI output between times t7 and t8 by register control pulse GP at time t6;
Accumulation F! by accumulation section transfer pulse PS! Transferred to B(12). At that time, the charges transferred between ts and t6 are transferred to the cleaning drain (1
B), and the storage section (12) has a shutter time S.
Only the charges at intervals indicated by L are stored and sequentially read out by the storage unit transfer pulse PS, gate pulse T, and read pulse PH after t8. The read charges are converted into video signals by a signal processing circuit (5) and then stored in a field memory (8).

[Problems to be Solved by the Invention] Since the conventional solid-state imaging device with an electronic shutter function is configured as described above, in order to obtain an appropriate exposure state both during normal imaging and during shutter operation, a steep response is required. iris (aperture) is required. In reality, since it is difficult to use the iris as described above, images are taken with the iris fixed so that proper exposure is achieved during shutter operation. Therefore, during normal imaging, there is a problem in that overexposure occurs and a signal at an appropriate level cannot be obtained.

This invention was made to solve the above-mentioned problems, and it is possible to generate a signal with an appropriate output level during shutter operation, and also to output an output signal with an appropriate level during normal imaging. The objective is to obtain a solid-state imaging device that can be obtained.

[Means for solving problems]

The solid-state 15x imaging device according to the present invention is provided with a light amount adjusting means that can vary the transmittance of light to the solid-state image sensor in front of the solid-state image sensor.

[Function] In the present invention, the light amount adjustment means is attached to the front surface of the solid-state image sensor, and the ND (ne
utral density7) Acts as a filter and adjusts light transmittance. In other words, an appropriate amount of light is irradiated onto the solid-state image sensor while the lens aperture is fixed to provide appropriate exposure during shutter operation.

[Embodiments of the invention] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a solid-state imaging device according to the present invention, and parts that are the same as those of the conventional device are given the same reference numerals and explanations will be omitted.

In FIG. 1, (3) is a light amount adjusting means attached to the front surface of the solid-state image sensor (2), and a liquid crystal or the like is used. (10) is a control circuit that adjusts the light transmittance of the optical mTA adjustment means (9) based on the input from the shutter command input terminal (7).

The solid-state image sensor (2) has a configuration as shown in FIG. 2, and performs an electronic shutter operation using the conventional driving method shown in FIG. This will be explained with reference to FIGS. 1, 3, and 5.

The solid-state image sensor (2) performs an electronic shutter operation using the conventional driving method shown in FIG. The lens used at that time (1
) aperture during shutter operation is exposure time T (t6 to t
7)).0 During normal imaging, the shutter open time is the l field period (1760 seconds) indicated by times t1 to t4, so if the aperture is kept as above, the shutter opening time is 1/ The exposure becomes 80/T times and the signal becomes saturated, making it impossible to obtain a signal at an appropriate level.Therefore, the light transmittance of the light amount adjustment means (9) is adjusted using the pulse NV shown in Figure 3, and normal imaging is performed. At the same time, ensure that a signal at an appropriate level is obtained. In other words, when this pulse NV is at L level, the transmittance is 1, and when it is at 'H' level, it is T/1.
/8G, the light amount adjusting means (9) is controlled. If it is a liquid crystal, if you control * to be at L level at time t3, the shutter opening time T
By 6, you can fully respond. By the above method, usually T
An output signal of an appropriate level can also be obtained for the V-picture image and the Rashata image.

In the above embodiment, a relatively easy-to-control device such as a liquid crystal is used as the light amount adjusting means (9), but if the light transmittance can be changed, the same effect as in the above embodiment can be obtained. play.

[Effects of the Invention] As described above, according to the present invention, since the light amount adjustment means composed of, for example, a liquid crystal is provided in front of the solid-state image sensor, appropriate exposure conditions can be maintained both during normal imaging and during shutter operation. 1. Output signals of appropriate levels can be obtained for both normal television images and shutter images.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram showing a solid-state imaging device according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a solid-state imaging device used in this invention, and FIG. Operation timing chart, fJS Fig. 4 is a configuration diagram showing a conventional solid-state imaging device. Fig. 5 is an operation timing chart of the solid-state imaging device of Fig. 4. (2)...Solid-state image sensor, (3)...Drive circuit, (
8)...Light amount adjustment means, (11)...Imaging section 7, (
12)...Storage section, (1B)...Charge sweep section. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] (1) A solid-state imaging device having an imaging section, an accumulation section that stores charges accumulated in the imaging section, and a charge sweep-out section, a drive circuit that provides an electronic shutter function to the solid-state imaging device, and a front surface of the solid-state imaging device. What is claimed is: 1. A solid-state imaging device, comprising: a light amount adjusting means that is provided in the solid-state imaging device and changes the transmittance of light irradiated to the solid-state imaging device.