JPH0445673A - solid-state imaging device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solid-state imaging device using time-division pixel shifting.

[Conventional technology]

In recent years, the development of solid-state image sensors has been remarkable.

On the other hand, there is also a strong demand for higher density of two-image information.

There are many demands that far exceed the capabilities of solid-state image sensors, and in order to meet these demands, we have developed a so-called spatial pixel shifting method that uses multiple solid-state image sensors and prisms, and uses microvibration of a single solid-state image sensor. It is well known to use a time-division pixel shifting method or the like.

The time-division pixel shifting method, which is performed by micro-vibrating a solid-state image sensor, can be implemented relatively easily as a means of obtaining monochrome information. However, as a means of obtaining color information, the micro-vibration mechanism has some drawbacks.

FIG. 4 is an example according to the prior art. According to FIG. 4, an image of a subject 1 is formed on a solid-state image sensor 3 through a lens 2. The video signal photoelectrically converted by the solid-state image sensor 3 is subjected to signal processing by the video amplifier 4, and then guided to the output terminal 5. The synchronizing signal generator 6 generates drive pulses for video signal processing as well as pulses for driving the X-axis vibration device 7 and the Y-axis vibration device 8. The solid-state image sensor 3 is vibrated in the horizontal and vertical directions by an X-axis vibrator 7 and a Y-axis vibrator [8.

FIG. 5 shows the movement of pixels of the solid-state image sensing device in the case of the conventional example shown in FIG. In FIG. 5, Px is a horizontal pixel pitch rPY is a vertical pixel pitch. First, in the first frame, the pixel 9 is at position a and captures image information, and in the second frame, the X-axis vibration device 7 shown in FIG. Incorporate. In the third frame, the horizontal movement is restored.

The Y-axis vibration device 8 shown in Fig. 4 moves vertically by Sy.
Pixel 9 captures image information at position C.

Similarly, in the fourth frame, the pixel 9 moves by Sx in the horizontal direction and Sy in the vertical direction, and the 9 pixels 9 capture image information at the position d.

Through the above operations, if the image information from the first frame to the fourth frame is combined, high-density image information with equivalently twice the number of elements of the original solid-state image sensor in both the horizontal and vertical directions can be obtained. is obtained.

[Problem to be solved by the invention]

However, the conventional technology relies on a method of mechanically directly vibrating the solid-state image pickup device horizontally or vertically, resulting in poor reliability and difficulty in applying it to a three-panel color camera using a prism or the like.

The present invention aims to eliminate these drawbacks and obtain high-quality image information without mechanically vibrating the solid-state image sensor.

[Means to solve the problem]

In order to achieve the above object, the present invention inserts a glass plate (for example, flat glass) between the lens and the solid-state image sensor so that its perpendicular line makes a predetermined angle with the lens optical axis, and the lens optical axis is aligned with the lens optical axis. By rotating about the rotation axis, the solid-state image sensor remains fixed and the imaging position is optically moved.

[Effect]

FIG. 1 shows the situation when light is incident on a flat glass plate 1o having a thickness t at an incident angle θ. When the incident angle θ is not 0°, the light passing through the glass is obtained as a parallel ray separated by S from the incident axis. This S is expressed by the following formula.

s=f (θ*t+n) However, n is the refractive index of the flat glass 10, so θ and t are set to certain values, and the flat glass 1 is set with the incident axis of light as the rotation axis.
When rotating 0, the passing light draws a circle with radius S.

Figure 2 shows θ and t so that the passing light draws a circle with radius Sr on a solid-state image sensor with horizontal pixel pitch Px and vertical pixel pitch py.
FIG. 3 is a diagram showing equivalent pixel positions when .

In the case of Px=Py and 5r=Px/27T, if the flat glass is rotated by 90 degrees for each frame, it becomes 4 frames, as if it were a solid-state image sensor with horizontal pixel pitch Px/2 + vertical pixel pitch Py/2.

High-density image information can be obtained.

Even in the case of Px#Py, 5r=(1/4~115)Pi
It is sufficiently effective if 5r=(1/4 to 115)Py.

〔Example〕

An embodiment according to the present invention will be described below with reference to FIG. An image of a subject 1 is passed through a lens 2 and passed through a flat glass 10 having a perpendicular angle to the optical axis to a solid-state image sensor 3.
image is formed. The video signal photoelectrically converted by the solid-state image sensor 3 is subjected to signal processing by the video amplifier 4, and then guided to the output terminal 5. The synchronizing signal generator 6 generates drive pulses for video signal processing as well as pulses for driving the rotating device 11 .

The rotating device W111 uses the optical axis of the flat glass 1o as the rotation axis.
It is driven so that each frame rotates 90 degrees, making one rotation every four frames. Every time the flat glass 10 rotates 90 @, the position of the pixel moves two equivalent times (as shown in Figure 2), so if the video signals from the first frame to the fourth frame are combined, both the horizontal and vertical In both directions, high-density image information can be obtained with equivalently twice the number of elements of the original solid-state image sensor.

Note that this embodiment deals with the case where the number of elements is equivalently doubled in both the horizontal and vertical directions, but when the number of elements is equivalently doubled only in the horizontal or vertical direction, the flat glass 10
It is sufficient to drive it so that it rotates once every two frames.

〔Effect of the invention〕

According to the present invention, since the vibration mechanism is eliminated as a one-time division pixel shifting mechanism and a two-rotation mechanism is used, reliability is high and noise is low. Furthermore, since there is no need to move the solid-state image sensor, it can be applied to a three-panel color camera using a prism or the like, which is highly effective.

[Brief explanation of the drawing]

, FIG. 1 is a diagram for explaining the present invention in detail, and FIG. 2 is a diagram showing equivalent pixel positions according to the present invention. FIG. 3 shows an embodiment according to the present invention, FIG. 4 shows an example according to a conventional example, and FIG. 5 shows equivalent pixel positions according to a conventional example. 2: Lens, 3: Solid-state image sensor, 4: Video amplifier, 6: Synchronization signal generation

Claims (1)

[Claims] 1. A flat transparent plate with a constant thickness is arranged between the lens and the solid-state image sensor so that its perpendicular line forms a predetermined angle with the optical axis of the lens, and the transparent plate is placed between the lens and the solid-state image sensor. It is equipped with a drive mechanism that rotates with the optical axis of the lens as a rotation axis, and the amount of parallel movement of the light flux generated when the light flux passes through the transparent plate is 1/4 to 1/2 of the pixel pitch of the solid-state image sensor. A solid-state imaging device characterized in that the thickness of the transparent plate and the angle between the transparent plate and the optical axis are set such that the driving mechanism rotates the transparent plate once at a predetermined frame period. 2. In the solid-state imaging device according to claim 1, between each of the color separation optical system and the plurality of solid-state imaging elements,
A solid-state imaging device comprising the transparent plate and the drive mechanism.