JPS60183880A - Solid-state image pickup element - Google Patents

Abstract

PURPOSE:To enable light measurement capable of holding gradation in the best condition by providing a photosensitive layer for measuring brightness of a picture in an area which will not affect picture information between respective photosensitive picture elements and by achieving an appropriate exposure level without fail. CONSTITUTION:Out of light beams incident on a solid-state image pickup element, light beams incident on a photoelectric picture element 2 are photoelectrically transferred and accumulated in each photoelectric picture element 2 in the same manner as a conventional solid-state image pickup element, and transferred as a signal charge. Picture information can be taken out. Since in terms of light beams incident on a lattice-shaped photosensitive layer 3 between respective photosensitive picture elements 2, the entire layer 3 is electrically connected, the light beam is converted into a light measuring signal corresponding to brightness of the overall picture and outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a solid-state image sensor, and particularly to a structure of a solid-state image sensor suitable for an electronic camera using the solid-state image sensor.

BACKGROUND TECHNOLOGY In conventional electronic cameras, for example, in which a solid-state image sensor such as a CCD is installed instead of a film using an optical system such as an eye-reflex camera, the solid-state image sensor currently used is based on a silver halide film. In comparison, the latitude that indicates the allowable amount of incident light is narrow, so the output voltage will be saturated for bright subjects, and there will be no output for dark subjects, making it difficult to accurately express gradations. It would become impossible to do so. Therefore, it is necessary to control the total amount of incident light, that is, the exposure level of the camera, with extremely high precision so that the brightness and dark levels of the object are well-balanced in the linear portion of the incident light amount-output voltage characteristic. However, such exposure control
If you use the viewfinder to measure the light as in a conventional single-lens reflex camera, it can be done with high precision; You can't measure without it/Kome Fif is multiple If! (If: fC. Furthermore, if the incident light is always divided between the shooting system and the photometry system using a half-mirror prism, etc., there will be a large amount of light loss due to the half-mirror prism, etc. You will be limited in terms of

Purpose: In view of the above points, the present invention instantaneously measures an appropriate exposure level during exposure and operates the shutter, thereby always achieving the appropriate exposure level to maintain the best gradation. The overall purpose of the present invention is to provide a solid-state image sensor that enables such photometry.

Overview This purpose is to transfer the image information between each photosensitive pixel in a solid-state imaging device that can extract image information by photoelectrically converting and transferring accumulated signal charges in a row of photosensitive pixels. The problem is solved by a solid-state image sensor, which is characterized by being provided with a photosensitive layer for measuring brightness.

EXAMPLE The present invention will be explained below with reference to an example shown in the drawings.First, FIGS. 1 and 2 show the basic structure of a general solid-state image sensor. are arranged in a matrix, and charges corresponding to the amount of incident light are temporarily accumulated in the photosensitive pixels 2. Then the third
3 and 4 show an embodiment of the present invention, and 3 (ma) is attached to the insulating film 1 similarly to the photosensitive pixels 2 between the photosensitive pixels 2 arranged in an IJ rack shape. The photosensitive pixel 2 is an electrically insulated lattice-shaped photosensitive layer, which in this case forms a photometric pattern extending over the entire VIf of the image, and measures the brightness of the entire image, that is, the exposure level. However, it may be provided only in a part of the screen, for example, in the center.

Since this embodiment is configured as described above, among the light incident on this solid-state image sensor, the light incident on the photosensitive pixel 2 is different from that of the conventional solid-state image sensor shown in FIGS. 1 and 2. In exactly the same way, each photosensitive pixel 2 undergoes photoelectric conversion, is stored, and is further transferred as a signal charge, so that image information can be extracted.On the other hand, light incident on the lattice-shaped photosensitive layer 3 between each of the nine photosensitive pixels 2 is Since the entire photosensitive layer 3 is electrically connected, it is converted into a photometric signal corresponding to the brightness of the entire image and output.

Figures 5 and 6 show the second fruit of the present invention 2G1! /I'
3' is a photosensitive layer in the form of a lattice attached to the surface of the photosensitive pixel 20, for example, on the window crow 4, at a portion corresponding to between the photosensitive pixels 2, as shown in FIGS. Similar to the embodiment shown in FIG. 4, an ill-light pattern is formed that spreads over the entire surface of the image, and the brightness of the entire image, that is, the exposure level e all, is determined. It may be provided only in a part of the area, for example, in the center.

This second embodiment operates in the same manner as the first embodiment, and further includes an M) direction IC on the surface of the solid-state image sensor to electrically insulate the photosensitive layer 3' from the photosensitive pixel 2. Since there is no need to form a gap, the photosensitive layer 3' can be formed complementary to the photosensitive pixels 2, so that the light incident between each photosensitive pixel 2 can be utilized as effectively as possible. A photosensitive layer 3' having a larger incident area can be obtained without reducing the number of photosensitive layers 3'.

FIG. 7 shows another embodiment of the present invention, in which the photosensitive layer 3 (or 3') forming a photometric pattern extending over the entire surface of the image is divided into a plurality of sections, for example, two sections in the drawing. That is, it is divided into a central section 3a and a peripheral section 3b, and it is possible to switch between center-weighted photometry, average photometry, etc. based on the photometric signals of the two sections 3a and 3b.

FIG. 8 shows a lens shutter type camera to which a solid-state image sensor according to the present invention is applied, and numeral 10 denotes a solid-state image sensor constructed according to the present invention, which is disposed on the imaging plane of a lens 11. 12 is a lens shutter, and 13 is an aperture. The operating principle of a camera with such a configuration will be explained with reference to the flowchart in FIG. The dimension 3' integrally counts the amount of incident light, and each photosensitive pixel 2 accumulates charges according to the amount of incident light. Here, when the integrated value of the amount of incident light detected by the photosensitive layer reaches a certain predetermined value, for example, the amount of light per unit area of the entire image increases to
When the standard saturation exposure amount of -20 is reached, the shutter 12
is closed, charge accumulation in each photosensitive pixel 2 is completed, and the charges accumulated in the latter photosensitive pixel are sequentially scanned and transferred, thus image information is extracted as a series of time-series electric signals.

Effects of the Invention As described above, according to the present invention, since a photosensitive layer for measuring the brightness of an image is provided in the area between each photosensitive pixel, there is no shadow (j(i) It is possible to measure the brightness, or exposure level, of an image without applying any radiation, and if the photosensitive layer is located close to the surface of the array of photosensitive pixels, the light incident on the area between each photosensitive pixel. In addition, by dividing the photometric pattern formed by the photosensitive layer into multiple sections and performing photometry independently in each section, it is possible to use center-weighted photometry for subjects such as center-weighted photometry. This provides an extremely effective solid-state image sensor structure that can be switched to an appropriate photometry method depending on the situation, and if this is incorporated into, for example, an automatic fogging lens-shutter camera and linked with the shutter, it will always provide the correct metering method. An image can be captured at a suitable exposure level, and image information with the best gradation representation can be retrieved.

[Brief explanation of the drawing]

Figure 1 is a plan view showing an example of a conventional solid-state image sensor;
The figure is an enlarged sectional view schematically showing the structure of the solid-state image sensor shown in FIG. 1, FIG. 3 is a plan view of an embodiment of the solid-state image sensor according to the present invention, and FIG. FIG. 5 is a plan view of a second embodiment of the present invention;
FIG. 6 is an enlarged cross-sectional view schematically showing the structure of the embodiment shown in FIG. A schematic diagram of the optical system of a lens-shutter camera incorporating
FIG. 9 is a flowchart showing the operation of the camera of FIG. 8. 1... Insulating film, 2... Photosensitive pixel, 3, 3'...
...Photosensitive layer, 4...Window glass, lO...
・Solid-state imaging - X element, l 1... Lens, 12...
...Shutter, 13...Aperture. Fig. 11 Fig. t2 Fig. 3 Fig. 4 Fig. 1-5 Fig. 〇 Fig. '7 Fig. S Fig. O 9

Claims (5)

[Claims] (1) In a solid-state image sensor that can extract 9 image information by photoelectric conversion and transfer of accumulated signal charge in a row of photosensitive pixels, image information is placed between each photosensitive pixel in an area that does not affect image information. A solid-state image sensor characterized by being provided with a photosensitive layer for measuring total brightness. (2) A patent claim characterized in that the photosensitive layer is divided into several layers in an insulating film that supports a row of photosensitive pixels, and forms a photometric pattern for measuring the brightness 'ff of the entire image. The solid-state imaging device according to range (1). (3) Claim (1) characterized in that the photosensitive layer is disposed close to the surface of the photosensitive pixel array and forms a photometric pattern for measuring the brightness of the entire image. ). (4) The photometric pattern is divided into multiple sections,
The solid-state image sensor according to claim (2)-1 or (3), wherein photometry is performed independently in each section. (5) The shutter is closed after an appropriate shutter opening time has elapsed based on the output signal from the photosensitive layer f: A solid-state imaging device according to any one of claims (1) to (4), characterized by: A lens-shutter camera that is biased towards the lens imaging plane.