JPS58215875A - Image pickup device - Google Patents

Abstract

PURPOSE:To improve resolution, by deflecting an object image beam by passing it through an acoustooptic element, and by performing the deflection and the scanning of the picture element of an image pickup picture by synchronizing them. CONSTITUTION:An object image beam passed through a photographing lens system 1 is deflected by an acoustooptic element 3 and reaches an image pickup surface 2. The image pickup surface 2 contains many picture elements lined up longitudinally and latitudinally. For each picture element, an electric charge proportional to the brightness of an irradiated object image is induced. The amount of the electric charge is taken out by scanning the picture element in horizontal or vertical direction on the image pickup surface 2 to be made to be a picture image signal. In this case, the element 3 is driven in syncyronization with the picture element scanning. Namely, if the element 3 is driven, the object image beam to be originally irradiated in the gap between picture elements is irradiated on one of picture elements adjacent to the gap. Therefore, if scanning the picture element by synchronizing with the irradiation, a picture image signal having doubled number of picture elements in appearance can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image capturing device, and in particular, the present invention relates to an image capturing device, and in particular, to
The present invention relates to an imaging device for obtaining operating power.

For example, an imaging system using a solid-state imaging device such as a MOS sensor or a CCD'ff irradiates an object f4.1 onto a large number of aligned pixels of the imaging device, and scans the pixels with fi-
image signals are obtained. The resolution of such an imaging device is determined by the arrangement pitch of the pixels that emit independent image (element) signals, and currently, due to the limits of the pixel arrangement pitch in semiconductor manufacturing technology, it is difficult to obtain high-resolution images such as photographs. The reality is that we cannot hope for power. However, in order to raise the limit of the solving power based on the pixel arrangement pitch, f'!
Various proposals have been made. One method is to image pixels with an amplitude that is half the distance of their array pitch, and to scan the pixels in synchronization with the vibration period, which apparently doubles the pixel array pitch. However,
This device is impractical because it requires a special drive to vibrate the pixels.

There is also a known device that divides the subject's light beam using a beam splitter, half mirror, etc., and arranges pixels on each of the divided beams to substantially narrow the pixel arrangement pitch, but this is difficult to adjust. Another problem is that a plurality of image sensors are required.

The present invention was made in view of these problems, and
Focusing on the use of an acousto-optic element known as a light deflector, the subject image beam is passed through the acousto-optic element and deflected, and the deflection is synchronized with the scanning of the pixels of the captured image. It is characterized by an increase in the apparent number of pixels.

The invention will now be described with reference to the illustrated embodiments. In FIG. 1, 1 is a photographic lens system, 2 is an imaging surface, and an acousto-optic element 3, which is a feature of the present invention, is disposed between the photographic lens system 1 and the imaging surface 2.

The imaging surface 2 includes a large number of pixels 4 arranged vertically and horizontally, as schematically shown in FIG. P indicates the arrangement pitch of the pixels 4. For example, in the case of a CCD, a charge is generated in each pixel 4 according to the brightness of the irradiated subject image (one incident light amount), and this charge charges the pixel 4 in the horizontal or vertical direction of the imaging surface 2. It is extracted by scanning and becomes an image signal.

Therefore, in the present invention, the subject image light beam that has passed through the photographic lens system 1 is deflected by the letter light and the optical element 3, and for example, the pixel 4
The effect is equivalent to vibrating with an amplitude of 1/2 of the array pitch, that is, 1/2P, or by setting up two image sensors with mutually shifted pixels on the beam split by a beam splitter. It produces the same effect.

As is well known, the acousto-optic element 3 utilizes the photoelastic effect of the acousto-optic medium 5 shown in FIG. Due to the interaction of the light passing through the medium 5 and the medium 5, the light is split into 0th-order diffracted light and 1st-order diffracted light. If the ultrasonic frequency is changed here, the diffraction angle Δθ of the diffraction source is modulated, so it can be applied to light deflection.

The light rays shown by solid lines in FIGS. 1, 37, and 4 are /ζ 0th-order diffracted lights that have passed through the two acousto-optic elements 3, and similarly, the broken lines indicate deflected 1st-order diffracted lights. Then, the acousto-optic element 3 is driven so that the amount of deflection t of the light beam indicated by the broken line on the captured image 2 becomes 1/2 of the arrangement pitch P of the pixels 4.

Of course, this acousto-optic element 3 is driven in synchronization with the scanning of the pixels 4. That is, when the acousto-optic element 3 is driven,
The object image light beam that should originally be irradiated onto the gap between the pixels 4 is applied to at least one of the pixels 4 adjacent to the gap.
Since it is irradiated upward, synchronize with that irradiation, that pixel 4
By scanning, it is possible to obtain an image signal with apparently twice the number of pixels.

Figures 3 and 4 explain the simplest one-dimensional light deflection, but in order to apply it to a two-dimensional direction, that is, a normal screen, it is necessary to use two lines whose light deflection directions are perpendicular to each other. An acoustic optical element may be used.

FIGS. 5(B) and 5(C) are schematic diagrams when the simplest black-and-white object 1 dust shown in FIG. 5(5) is imaged and reproduced; What was used (B
) indicates not used. As described above, it will be understood that according to the present invention, an effect equivalent to doubling the number of pixels can be obtained. Of course, the present invention can also be applied to objects including intermediate tones and color virtual images using the same principle as described above.

Note that the acousto-optic element 3 is the photographic lens system 2 in the above embodiment.
However, the same effect can be obtained even if the lens system 2 is placed in front of the photographic lens system 2.

In summary, the present invention focuses on the light deflection effect of an acousto-optic element, and uses this element to deflect the subject image light beam and apply it to the pixels on the imaging surface, which increases the apparent number of pixels. This can improve resolution.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of an imaging device according to the present invention, Fig. 2 is a schematic diagram showing the arrangement of pixels included in the imaging surface, Fig. 3 is a conceptual diagram of an acousto-optic element, and Fig. 4 is a conceptual diagram of an acousto-optic element. Schematic diagram showing the state of optical deflection according to Fig. 5, (B), (C
) are schematic diagrams showing the subject and the second side of the reproduced image after imaging, respectively. 1... Photographing lens system, 2... Imaging direction, 3... Sound object optical element, 4... Pixel. Patent applicant: Asahi Optical Industry Co., Ltd. Agent: Kunio Miura

Claims (1)

[Claims] (1) In the imaging device 6, pixels that convert optical signals into electrical signals are arranged vertically and horizontally, a subject is irradiated onto the imaging surface, and the pixels are scanned to obtain an image of the subject. Photographing 1 characterized in that an acousto-optic element through which the object mound light passes is disposed in front of the imaging screen, and an image signal is obtained by synchronizing the optical deflection by the acousto-optic element with the scanning of the pixels. Home accessories. (2. Claim M1 provides an imaging device in which the amount of light applied to the imaging surface by the optical element is approximately 1/2 of the pixel arrangement pitch.