JPH01154684A - High sensitive camera device - Google Patents

Abstract

PURPOSE:To reduce fixed pattern noise by correcting the address of a memory in order to coincide the spatial position with the picture from a solid image pickup element and the picture of a memory space and adding addressed picture element information with the picture element information from the solid-state image pickup element with the same address as the picture element information. CONSTITUTION:When an imager 2 is shifted from the frame F(i) of i-th to the frame F(i+l) of (i+l)-th, shifting quantity is detected by a positioner position detecting circuit 6. The address of an FM 12 is corrected in order to coincide the spatial position with the picture from the imager 2 and the picture of the FM 12 space by an address correction circuit 7 based on the shifting quantity detected. On the other hand, the picture element information of the imager 2 is outputted to an adding circuit 11 through an amplifier 8, a signal process circuit 9 and an ADC 10. The picture element information from the FM 12 having the address after correction and the picture element information from the imager 2 having the same address as the said picture element information are added and written into the said address of the FM 12 through a read- write circuit 13.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a high-sensitivity camera device.

[Conventional technology]

Conventionally, as a method for reducing fixed pattern noise caused by dark current in a solid-state image pickup device, for example, an imager, a method of keeping the imager at a low temperature using an auxiliary device has been proposed.

(Problems to be Solved by the Invention) Conventional high-sensitivity camera devices have the following problems (1) to (3) because the imager is kept at a low temperature by an auxiliary device. That is, (1) It takes time for the imager to reach a predetermined temperature after turning on the power switch ONL.

■Large cooling heat treatment mechanism.

■Measures against condensation are required.

■Large amount of power is consumed for cooling.

This invention was made to solve the above-mentioned problems, and aims to further increase the ratio between a signal and fixed pattern noise caused by dark current.

(Means for solving the problem) The high-sensitivity camera device according to the present invention
Shifting means for relatively shifting the solid-state image sensor and the optical input image, and address correction for correcting the memory address so that the spatial position of the image shifted from the solid-state image sensor and the image in the memory space coincides with each other. means for adding the pixel information from the memory with the corrected address and the pixel information from the solid-state image sensor f having the same address as this pixel information; It is provided with a writing means for writing an old address into the address.

(Function) The high-sensitivity camera device according to the present invention captures a solid-state image sensor composed of a plurality of pixels and an optical input image frame by frame.
The address of the memory is relatively shifted by the shift means, and after the shift, the address of the memory is corrected by the address correction means so that the spatial position of the image obtained from the solid-state image sensor and the image of the memory space match, and the corrected address is The attached pixel information and the pixel information from the solid-state image sensor having the same address as this pixel information are added by the adding means, and the pixel information after the addition is written to the same address as above by the -F
Get into it.

[Embodiment] FIG. 1 shows an embodiment of the present invention. In the figure, reference numeral 1 denotes an imaging lens that forms an incident image onto an imager (solid-state imaging device) 2. The imager 2 converts optical signals into electrical signals, and its effective area is larger than the effective screen F ref shown in FIG.

3 is an imager driver which drives the imager 2. Reference numeral 4 denotes a positioner (shifting means), which is composed of an electrostrictive element, etc., and shifts the imager 2 frame by frame so that the effective screen Frer is within its effective area. A positioner driver 5 drives the positioner 4. Reference numeral 6 denotes a positioner position detection circuit for detecting the amount of shift of the positioner 4. Reference numeral 7 denotes an address correction circuit (address correction means) which corrects the address of the FM (frame memory) 12 so that the shifted image from the imager 2 matches the spatial position of the image in the memory space. be. Reference numeral 8 denotes an amplifier for amplifying the electric signal from the imager 2. Reference numeral 9 denotes a signal processing circuit that performs signal processing such as pedestal level clamping and γ correction, as in the conventional example. 10 is A
The DC converter converts the analog signal from the signal processing circuit 9 into a digital signal. Reference numeral 11 denotes an adding circuit (adding means) which adds pixel information from the FM 12 having the corrected address and pixel information from the solid-state image sensor having the same address as this pixel information. 1
3 is a read/write circuit (writing means), and the F
The image information is read from M12, and the pixel information after addition is written to the address before correction. A clock generator 14 outputs a clock signal to the imager driver 3, positioner driver 5, address correction circuit 7, and ADCIO.

Next, the operation will be explained.

Imager 2 is in the i-th frame F(i), and the leading 0 of the effective screen F rat is the coordinates of imager 2 (m+
, n+).

From this state, if imager 2 is shifted to (i+4th frame F(i+J) by positioner 4,
The first point (■) of the effective screen Frat is located at the position (ml, 1.nl, plate) in the coordinates of the imager 2.

However, n=o-8.

Imager 2 selects the i-th frame F (i) to (i+
j! )-th frame F(i+J2), this shift amount is detected by the positioner position detection circuit 6, and based on the detected shift amount, the address correction circuit 7 compares the image from the imager 2 with the FM12. The address of the FM 12 is corrected so that the spatial position matches the spatial image.

On the other hand, pixel information of the imager 2 is output to the adder circuit 11 via the amplifier 8, the signal processing circuit 9, and the ADCIO.

Then, this adder circuit 11 adds the pixel information from the FM 12 having the corrected address and the pixel information from the imager 2 having the same address as this pixel information, and the pixel information after the addition is read out and read out. It is written by circuit 13 to the same address as above in FM12.

Thereafter, the above-described operation is repeated for each shift.

In this embodiment, the imager 2 is set to 9 as shown in FIG.
Since the signal components are shifted by 9 times, they are added in the same phase and multiplied by 9 times, but the dark current is added by 9 pixels, and its dispersion is 1/r.
'g, ie, 1/3, and the ratio of the signal to dark current fixed pattern noise, ie, the S/N ratio, becomes 3 times.

From this, it can be seen that the S/N ratio is numerically improved by a factor of f1. in this case,! It is necessary that the states of all the states are different.

Therefore, the sensitivity of the camera is increased and a low speed shutter can be released.

Although this embodiment describes an example in which the imager 2 is shifted, the intended purpose can also be achieved by shifting the optical input image.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to obtain a high-sensitivity camera device that can further increase the ratio between a signal and fixed pattern noise caused by dark current.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the invention, FIG. 2 is a diagram explaining the principle of the invention, and FIG. 3 is a diagram showing an example of displacement of the imager. 2------Imager 4---Positioner 7---Address correction circuit 11---Addition circuit 13---Reading/writing circuit

Claims (1)

[Claims] A solid-state image sensor with multiple pixels and each frame
A shift means for relatively shifting the solid-state image sensor and the optical input image, and an address for correcting the memory address so that the image obtained after shifting from the solid-state image sensor and the image in the memory space match in spatial position. a correction means; an addition means for adding pixel information from the memory with the corrected address and pixel information from the solid-state image sensor having the same address as this pixel information; A high-sensitivity camera device comprising a writing means for writing to an address.