JPS61256763A - electronic steel camera - Google Patents

Abstract

PURPOSE:To obtain an electronic still camera having excellent picture quality, by providing light shielding films so that vertical transfer electrodes can receive light at every other electrode in a CCD used, and shielding external light by a shutter in a light path in the camera. CONSTITUTION:Light is received even in a charge transfer part, and signal charge (g) is stored in (n), (n-2) ... at every other electrode. The signal of the seventh electrode F is transferred to a horizontal transfer part (a) without mixing by using the first - sixth electrodes, in which the signal is not inputted. The signal of the ninth electrode can be transferred without mixing with the signal of the seventh electrode when the signal of the seventh electrode is transferred to the fifth electrode or the horizontal transfer electrode closer to the fifth electrode. In accordance with this system, the signal on the first line (d) is transferred to the horizontal transfer part at t1. The signal on the second line (f) is transferred to the first line at t2. At the same time, the signal on the first line is read to a preamplifier (b). This procedure is repeated up to the nth line (m). This CCD can be formed by a conventional method. Though the degree of integration is not improved, resolution is improved by about twice, and the electronic still camera having excellent picture quality is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electronic camera using a solid-state imaging device (CCD), and particularly to an electronic still camera.

(Prior art and its problems) Such electronic cameras are well known. CC used here f
Currently, D of about 257i pixels is in practical use, but this number is insufficient for producing still images in which image defects are particularly noticeable. For the time being, approximately 400,000 pixels are required to obtain a satisfactory resolution.However, as the degree of integration of the CCD increases, the area of the scanning circuit for signal readout becomes larger. In other words, the area ratio of the photoelectric conversion part in the CCD decreases, resulting in a decrease in sensitivity.
is difficult to manufacture, and yields inevitably deteriorate.

(Problems to be Solved by the Invention) The present invention aims to solve the drawbacks of the prior art without imposing excessive demands on the manufacturing process 2 and without deteriorating the yield. The object of the present invention is to provide an electronic camera, especially an electronic still camera, which can obtain the necessary resolution without any problems.

(Means and effects for solving the problems) The basic idea of the present invention is not to increase the degree of integration of the CCD in order to improve the resolution, but instead to increase the resolution of the CCD by increasing the degree of integration of the CCD. The key point is that it has a photoelectric conversion function. In conventional CCDs, the charge transfer section is covered with a luminescent film in order to prevent the charges inside the transfer section from being affected by light incident during charge transfer. However, in the COD according to the present invention, a light film is not provided over the entire area of the charge transfer section adjacent to the photoelectric conversion section, but a light film is provided so that every other vertical transfer CCD electrode can receive light. There is. Therefore, vertical transfer CO that can receive light during charge transfer
External light exposure of the D electrode is performed by a shutter placed in the optical path of the camera. Therefore, the shutter in the present invention has an important role, that is, it has an important role beyond the role of a conventional shutter, such as adjusting the amount of light and preventing blurring of a moving image.

In the present invention, the transfer section also receives the image light, and as a result, the signal charge q is distributed at every other electrode (n +
n-2, n-4,...). If all the signals are transferred simultaneously by two-phase or three-phase drive as in the past, the signals will be mixed with each other.

To solve this problem, the present invention devises a reading method, and the basic idea thereof is as follows.

For example, the signal under the 7th electrode in Figure 5 is transferred to the horizontal transfer unit by 2-, 3-, or 4-phase drive using the 1st to 6th electrodes that do not contain signals. It can be transferred without mixing with the signal below. The signal under the 9th electrode is
If the signal under the 7th electrode is transferred under the 5th electrode or an electrode close to the transfer electrode, it will be mixed with the signal under the 7th electrode even if the transfer starts. Transfer without any hassle! Wear. Below, the 11th, 13th,...
. . . If the signals under the n-th electrode are also transferred in the same way, they can be sequentially transferred without being mixed with each other.

What is called a formula-T! be.

In Fig. 6, at tl, the signal on the first line is transferred to the horizontal transfer unit, and at t2, the signal on the second line is transferred to the first line, and at the same time, the signal on the first line in the horizontal transfer unit is transferred to the preamplifier. Read to.

This is repeated for the signals up to the nth row.

Regarding the accordion method, IEDM 1984 4th
0 pages, Ph1lips Re5search I, abo
, which is described in detail in the Netherlands,
This method is roughly as follows. That is, in the first step, the width of the cell in which the signal charge exists is expanded one by one starting from the exit end so that the width becomes double. When the width of all cells is doubled, half of the signal charges closest to the exit are pushed out from the exit.

At this time, the width of all cells is doubled, so the second
Half of the signal charge remaining in stage 1 will have four electrodes per one electrode, and can also be read out in the usual manner.

When using COD for color images, CCD
A microfilter is placed above to color code each pixel. In that case, if polysilicon is used for the transfer electrode, the photosensitivity of the transfer section will decrease with respect to B light. Therefore, it is advantageous to use the cell of the charge transfer section for R light and/or G light.

゛The CCD used in the electronic power supply according to the present invention does not have a particularly high degree of integration, so it can be manufactured using the conventional manufacturing process, and the yield will not deteriorate. Nevertheless, the resolution can theoretically be almost doubled.

Since the electronic camera according to the present invention has an extremely high resolution, it is particularly suitable for still cameras where defects in image quality are easily noticeable. However, the electronic camera according to the present invention has no technical problems when used as a cine camera. Therefore, sufficient characteristics can be obtained even when used as a cine camera.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

The electronic camera according to the invention consists of a dark box, imaging optics, a shutter and a COD. Since the individual configurations and interrelationships of these elements are well known, a description thereof will be omitted.

FIG. 1 shows an embodiment of a COD used in an electronic camera according to the present invention. 1 is a photoelectric conversion section, and 2 is a charge transfer section. In conventional CODs, the charge transfer section is entirely covered with a shimmering film, but in the present invention, since the charge transfer section also performs photoelectric conversion, the shimmering film 3 has only one vertical transfer COD electrode. It is set up so that it can be disturbed at any time. 4
represents a transfer gate, and according to the present invention, these transfer gates are used to transfer the charge of the photoelectric conversion section 1 to the charge transfer section 2 after sending all the charges of the charge transfer section to the horizontal transfer section 5. .

Light is applied onto this CCD through the imaging optical system of the camera. When exposed to light, each photoelectric conversion unit 1
Charges corresponding to the amount of light are accumulated in the charge transfer section 2. Next, this charge is read out in accordance with the scanning order, but during this readout, the amount of charge in each pixel must not change depending on the amount of light. 1. During the charge transfer period, the shutter is closed and the COD Avoid exposing it to light.

FIG. 2 is a cross-sectional view of the charge transfer section 2. As shown in FIG. COD board 6
The potential valleys are indicated by broken lines within the figure. Charges 9 excited by light are accumulated within this valley. These charges can be shifted towards the exit by applying a specific potential to 107 and 8, which is also well known.
Detailed explanation will be omitted.

In the CCD in the illustrated embodiment, two electrodes 7, 8 are provided for each pixel. Therefore, in conventional method 1, the charges of all pixels cannot be read out independently, and four transfer electrodes are required to transfer the signal valve of one pixel. Therefore, the signals of all pixel parts are divided into A field and B field.
Either the signals are transferred in fields and read out (frame accumulation mode), or the two-pixel signals are combined into one signal and then transferred and read out (field accumulation mode), but either way, the resolution is not as great as the accordion method. I can't do it.

If the COD according to the invention is used for color images, a microfilter can be placed on the CCD and each pixel can be used for a single color (R, CR, B). Examples of color-coding of each pixel in that case are shown in FIGS. 3 and 4. In FIGS. 3 and 4, the structure of the CCD itself is the same as that in FIG. 1. In the embodiment shown in FIG. 3, the pixels of the charge transfer section 2 are not used for B color. Generally, when polysilicon is used for the transfer electrode 7.8, the light sensitivity decreases in the 8-color spectral range! , in which case the embodiment of FIG. 6 is advantageous. Further, if there is no problem of such a decrease in photosensitivity, the embodiment shown in FIG. 4 can also be used.

In the COD "t' used in the present invention, the photoelectric conversion section can be configured as a photodiode or MO8 structure, and the charge transfer section can be configured as a CCD or BBD.

Further, it is useful for the area ratio of the vertical transfer CCD electrode that can receive light to the vertical transfer CCD electrode that cannot receive light to be approximately 1:1 to 5:1.

Shutter can be mechanical shutter, liquid crystal shutter or PL
It can be configured as a ZT chassis.

Generally, one frame of a TV screen is made up of A field signals made up of signals on odd rows and B field signals made up of signals on even rows. Therefore, in the readout method of the present invention, it is necessary to separate the A field signal and the B field signal. The following three methods can be cited as this separation method.

■ Two horizontal transfer sections are provided, and the odd-numbered row signals are transferred using the A horizontal transfer section, the even-numbered row signals are transferred using the iB horizontal transfer section, and the A field signal and the B field signal are transferred using the iB horizontal transfer section. These signals are simultaneously recorded on a floppy disk using an inline double-gap magnetic head as a two-file P signal.

(2) One horizontal transfer section is used, and after inputting its output to a preamplifier, the changeover is performed between an even field and an odd field using a changeover switch as shown in FIG.

- Using one horizontal transfer section, input all the signals once into the memory through the preamplifier, and then separate and extract the A field and B field signals from there.

The present invention may be implemented using any of the methods described above.

(Effects of the Invention) As described above, according to the electronic camera of the present invention, by providing the charge transfer section of the COD used therewith with a photoelectric conversion function, resolution power can be enhanced and good image quality can be obtained. Also, there is no way this COD has increased the degree of integration.
, which can be manufactured using conventional manufacturing processes, so there is no problem with yield deterioration.

[Brief explanation of the drawing]

FIG. 1 is a plan view schematically showing a part of the CCD used in the present invention, FIG. 2 is a sectional view schematically showing a part of the COD [load transfer section, and FIGS. 3 and 4 are , a diagram corresponding to FIG. 1 when the CCD is used for color images, FIG. 5 is a diagram explaining the signal readout method used in the present invention, and FIG. 6 is a diagram explaining one example of the signal readout method. , FIG. 7 is a diagram illustrating an example of a method for separating signals of even and odd fields constituting one frame screen. Reference numeral 1 in the figure: Photoelectric conversion section, 2: Charge transfer section, 3: Shimmering film, 4: Transmission gate, 5: Horizontal transfer section, 6
... Substrate, 7.8... Electrode, 9... Charge. Procedural amendment February 1985 / Deadline

Claims (3)

[Claims] (1) In an electronic still camera consisting of a dark box, an imaging optical system, a shutter, and a solid-state image sensor, the solid-state image sensor consists of a photoelectric conversion section, a charge transfer section, and a transfer control section,
Every other vertical transfer CCD electrode is enabled to receive light, and while the shutter is closed, the charges generated in the photoelectric conversion section and the vertical transfer CCD electrode are sequentially transferred from those closest to the horizontal charge transfer section of the vertical transfer CCD electrode. 1. An electronic still camera, comprising a transfer control section for reading data, and a shutter that opens during a light reception period and closes during a charge transfer period, and is disposed in an optical path of the camera. (2) The electronic still camera according to claim 1, wherein the electronic still camera is operated using an accordion method in which charges are read out. (3) The electronic still camera according to claim 1, wherein a part of the charge transfer section receives R and/or G light.