JPH0319480A - Image pickup device - Google Patents

Abstract

PURPOSE:To improve an S/N by providing a switch switching 1st and 2nd amplifiers alternately with a control pulse from a photoelectric conversion means driver so as to output two systems of signals outputted from the photoelectric conversion means with tilt grating arrangement as one system of signal by means of the switch while being subjected to 1/2 frequency division. CONSTITUTION:A tilt grating arrangement photoelectric conversion means 11 uses a pulse resulting from a control pulse outputted from a photoelectric conversion means driver 12 while being 1/2 frequency division by a 1/2 frequency division means. Lines 1, 2 read simultaneously are inputted to a switch 14 via a 1st amplifier 16 and a 2nd amplifier 17 and switched alternately to the 1st amplifier and the 2nd amplifier with a control pulse from the photoelectric conversion means driver 12 and outputted to an output terminal 15 as one system of signal. Thus, an excellent picture with high resolution, high S/N and without moire is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an imaging device such as a video camera having a light-to-electricity conversion means. BACKGROUND OF THE INVENTION In recent years, solid-state image sensors have been used in imaging devices such as video cameras. Small and lightweight, with uniform spatial resolution across the screen.
It has various advantages such as low afterimage. However, HDTV
, HDTV, etc., as further improvements in resolution are desired.
It is becoming difficult to increase the number of pixels in solid-state image sensors due to IC processing accuracy and yield issues. Therefore, in order to cope with the increase in the number of pixels, a diagonal grid arrangement photoelectric conversion means was devised. This will be explained below with reference to the drawings. FIG. 3 shows a conventional imaging device 30.
This is a block diagram showing the configuration of the . In FIG. 3, the incident light that has passed through the imaging lens 20 is input to the diagonal grid arrangement photoelectric conversion means 2l, undergoes optical-electrical conversion, and is converted into two systems of signals by simultaneous reading of two lines, each of which is sent to the first amplifier. 2
2. Input to the second amplifier 23. The two systems of signals are the outputs of the diagonal grid photoelectric conversion element 2l and are in an offset sampling relationship. Since reading is performed using the same clock, the data is output at the same time. Therefore, of the two systems, the timing of the l system is shifted by 1/2 pixel by the delay element 24, added by the adder 25, and outputted to the output terminal 26. As a result, the horizontal resolution is apparently doubled. Problem to be Solved by the Invention However, in the above structure, the delay time of the delay element 24 cannot be set exactly to 1/2 pixel.
As shown in FIG. 4(A), b is 9/2 and the moiré does not disappear, and as shown by X in FIG. 4(B),
Since noise factors between pixels are also added, there is a problem in that the SN (signal-to-noise) ratio of the signal obtained from the imaging device 30 decreases.

Means for Solving the Problems In order to solve the above problems, an imaging device according to the present invention includes an imaging lens, a diagonal lattice arrangement photoelectric conversion means in which optical sensors are arranged in a diagonal lattice shape, a sinch, a photoelectric conversion means drive device, It is composed of a 1/2 frequency dividing means, a first output amplifier, a second output amplifier, and an output end, and the incident light passing through the imaging lens is converted into the diagonal grating arrangement light! By means of conversion means, light and
After electrical conversion, during an odd field, the odd line signal is output to the first amplifier, the even line signal is output to the second amplifier, and during the even field, the even line signal is: The signals of odd lines output to the first amplifier are output to the second amplifier, and the signals passing through the first amplifier and the signals passing through the second amplifier are manually input to the switch, The switch alternately switches between the first amplifier side and the second amplifier side according to a control pulse output from the photoelectric conversion means drive device, and outputs a signal to an output terminal,
The control pulse output from the photoelectric conversion means drive device is frequency-divided by 1/2 by the 1/2 frequency dividing means,
Two systems of signals having an offset sampling relationship input to the diagonal lattice photoelectric conversion means and output from the diagonal lattice photoelectric conversion means are resampled by the switch and output as l-system signals. There is an iN commandment. Due to the above-mentioned structure, the imaging device of the present invention has a high degree of resolution, is free from moiré, and has a high signal-to-noise ratio compared to conventional devices. Embodiment Hereinafter, an embodiment of an imaging device according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the imaging device of the present invention. In FIG. 1, reference numeral 1 denotes an imaging lens, and a subject image formed by the imaging lens 1 undergoes optical-to-electrical conversion by a photoelectric conversion means 1l arranged in a diagonal grid. Here, in the diagonal lattice arrangement photoelectric conversion means 1l, optical sensors are arranged in a diagonal lattice shape as shown in FIG. Now, it is an odd field and line 1,
Assume that line 2 is being read simultaneously. The read clock uses a pulse obtained by dividing the control pulse output from the photoelectric conversion means drive device 12 into 1/2 by the 1/2 frequency dividing means. Simultaneously read line l line 2
are the first amplifier l6 and the second amplifier l7, respectively.
The signal is input to the switch 14 via the switch 14. The switch 14 is alternately switched to the first amplifier side and the second amplifier side by a control pulse output from the photoelectric conversion means drive device 12, and is outputted to an output 415 as an l-system signal. The control pulse that drives the switch 14 has twice the frequency of the control pulse that drives the diagonal lattice photoelectric conversion means 11, and in the diagonal lattice photoelectric conversion means 11, each pixel at the offset sampling position By configuring the image to be re-sampled, moire disappears, and since the image is re-sampled at the timing where the pixel exists, no unnecessary noise is introduced. Note that an analog-to-digital converter is provided between the first amplifier 16, the second amplifier 17, and the switch I4, and the entire system is a digital circuit.
You may give a precept. Further, the switch 14 itself may be an analog-to-digital converter having a sample and hold function. It is more desirable to double the number of pixels (scanning lines) in the vertical direction in order to improve the resolution in the horizontal direction. In this case, in the even field, even lines are output to the first amplifier 16, and odd lines are output to the second amplifier 17.
Field flicker is reduced due to the precept. Effects of the Invention As described above, according to the imaging device of the present invention, excellent images with high resolution, a high signal-to-noise ratio, and no moiré can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an imaging device lO in an embodiment of the present invention, and FIG. 2(A) is a diagonal grid arrangement photoelectric conversion means l1.
FIG. 2 (CB) is a schematic diagram showing the arrangement of optical sensors in the image pickup device 10; FIG. 3 is a block diagram of the conventional image pickup device; FIG. 4 (A)
is an explanatory diagram showing the effect of the delay element 24 in the conventional example, and FIG. 4(B) is an explanatory diagram showing the effect of the adder 25 in the conventional example.

Claims (1)

[Claims] an imaging lens, a diagonal grid photoelectric conversion means in which optical sensors are arranged in a diagonal grid pattern, a switch, a photoelectric conversion means drive device, a 1/2 frequency dividing means, a first output amplifier, a second output amplifier, and an output end; The incident light that has passed through the imaging lens is optically/electrically converted by the diagonal grid arranged photoelectric conversion means, and in the odd field, the odd line signal is output to the first amplifier, and the even line signal is output to the first amplifier. are output to the second amplifier, and in an even field, the signals on the even lines are output to the first amplifier, the signals on the odd lines are output to the second amplifier, and the signals on the odd lines are output to the second amplifier. The signal that has passed through the first amplifier and the signal that has passed through the second amplifier are input to the switch, and the switch is activated by the control pulse output from the photoelectric conversion means drive device to the first amplifier side. The control pulse is alternately switched to the second amplifier side and outputs a signal to the output terminal, and the control pulse output from the photoelectric conversion means drive device is frequency-divided by 1/2 by the 1/2 frequency dividing means, Two systems of signals having an offset sampling relationship, which are input to the diagonal grid photoelectric conversion means and output from the diagonal grid photoelectric conversion means, are resampled by the switch and output as one signal. An imaging device characterized by: