JPS63284978A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To attain high resolution and miniaturization by providing a piezoelectric linear actuator using a sinusoidal wave signal to drive a transparent parallel plate provided between an object and a solid-state image pickup element so as to move the parallel plate horizontally and vertically for each peak of a half cycle by 45 deg.. CONSTITUTION:A radiated light from an object is collected 2 and projected to a two-dimension solid-state image pickup element 5 via a parallel plate 11. The parallel plate 11 is supported to a bimorph type piezoelectric actuator 12 via a rotary shaft 10. The parallel plate 11 while being controlled by a control section 13 is moved by 45 deg. in horizontal/vertical direction for each half cycle of a sinusoidal wave signal by the actuator 12 and the image pickup element 5 applies storage for the peak area period of the sinusoidal wave signal and readout in other period. This is equivalent to the state that photodetection sections 1-9 of each picture element of the image pickup element 5 are moved to dead bands 1'-9' in an oblique direction of 45 deg.. The value of the areas 1-9, 1'-9' detected by the image pickup element 5 is subject to picture processing 14 and displayed (4). Thus, high resolution is obtained without increasing number of picture elements to attain miniaturization.

Description

[Detailed Description of the Invention] [Summary] The present invention aims to improve the resolution of a solid-state imaging device using a two-dimensional solid-state imaging device, and to reduce the size and cost of the device. and a piezoelectric actuator that drives the parallel plate with a sine wave signal, displacing the parallel plate in a direction of 45° with respect to the horizontal and vertical directions at every half-cycle peak of the sine wave signal, and driving the parallel plate with a sine wave signal. The solid-state image sensor is configured to perform accumulation during the period of the peak region and readout during other periods, and uses a small and inexpensive sine wave drive actuator and increases the number of pixels by scanning in only one direction. , making it possible to obtain high-resolution images.

[Industrial application field]

The present invention relates to a solid-state imaging device using a two-dimensional solid-state imaging device, and more particularly to a solid-state imaging device that achieves higher resolution, smaller size, and lower cost of the device.

Conventionally, a pixel compensation method has been proposed that slightly displaces the observation field and obtains the same effect as equivalently increasing the number of pixels of an image sensor.

In such a pixel capture method, the field-of-field displacement structure for obtaining compensation pixels is complicated and expensive, so a solid-state imaging device that can increase the number of pixels and obtain high resolution with a simple and inexpensive field-of-field displacement structure is needed. It is requested.

[Conventional technology]

FIG. 5 is a schematic diagram of a conventional solid-state imaging device, and FIG. 6 is a diagram for explaining scanning of the scanning optical system of the conventional solid-state imaging device.
FIG. 7 (tag, bl) shows a drive voltage waveform diagram of a conventional piezoelectric actuator.

In FIG. 5, the optical axis 1 is scanned in the horizontal direction by the rotational vibration of the first filter 6 in the horizontal direction, and scanned in the vertical direction by the rotational vibration of the second filter 7 in the vertical direction. and enters the solid-state image sensor 5.

The method for scanning a solid-state image sensor using the above-described scanning optical system is described in the sixth section.
This will be explained with reference to FIG. 7 and FIG.

FIG. 7 shows a voltage waveform diagram for driving the first and second piezoelectric actuators 6 and 7, in which (a) shows that each filter is driven at the same frequency with a phase difference, (b) ) indicates the case where each filter is driven at a different frequency. The I (level) in the figure scans the field of view of the solid-state image sensor to the right in the horizontal direction and downward in the vertical direction, and the L level scans in the opposite direction to the above.

FIG. 6 is a diagram showing the pixel arrangement of the solid-state image sensor 5 having 5 (horizontal) x 5 (vertical) pixels, and each pixel 13-1 to 13-25 in the solid-state image sensor 5 has a pixel width and a pixel width. They are arranged in a grid pattern with an interval d between them.

In such a solid-state image sensor 5, now FIG. 7+8),
(At the timing A shown in bl, the field of view of the solid-state image sensor corresponds to ■ in Figure 6, at the timing B, the field of view ■ in Figure 6, at the timing C, the field of view ■ in Figure 6, and at the timing D This corresponds to field of view ■ in Figure 6.

By performing such scanning, the number of pixels is 10×10
= 100, the number of elements using the conventional scanning method is 5X
This results in a resolution four times higher than 5=25.

The pixels thus obtained by the solid-state image sensor 5 are sequentially subjected to image processing by the signal processing section 3, and the images are displayed on the display section 4.

[Problem that the invention seeks to solve]

In the method of scanning the field of view of the solid-state image sensor described above,
In order to fix the field of view during the accumulation operation of the image sensor, a rectangular wave or trapezoidal wave drive signal is used for displacement in the X and Y directions, and the response speed is compared with this rectangular wave or trapezoidal wave drive signal. A high-performance multilayer piezoelectric element is used.

This laminated piezoelectric actuator is very expensive and has a large size, which hinders miniaturization and cost reduction of the device.

Furthermore, the circuits that generate the rectangular waves and trapezoidal waves are also complicated, which is one of the factors that hinders price reduction.

The present invention was created in view of these points, and an object of the present invention is to provide a solid-state imaging device that increases the number of pixels with a simple field-of-view displacement structure, provides high resolution, and can be made smaller and lower in price. It is an object.

[Means for solving problems]

FIG. 1 shows a schematic diagram of the principle of the solid-state imaging device of the present invention, which includes a condensing lens 2 that condenses light emitted from a subject 1;
A parallel plate 11 that transmits light and a piezoelectric actuator 12 that drives the parallel plate 11 with a sine wave signal are provided between the solid-state image sensor 5 that images the subject and a piezoelectric actuator 12 that drives the parallel plate 11 with a sine wave signal. A control unit 1 displaces the flat plate 11 in a direction of 45 degrees with respect to the horizontal and vertical directions, and controls the solid-state image sensor 5 to perform storage during the period of the peak region of the sine wave signal and read out during other periods.
3.

[Effect]

FIGS. 2(a), (b), and (C) are diagrams for explaining the relationship between the scanning of the parallel plate of the present invention and the operation of the solid-state image sensor, and FIG. 3 is for explaining the scanning method of the present invention. This is a diagram for

The parallel plate 11 has its transmitting surface perpendicular to the optical axis, and is actuated by the piezoelectric actuator 12 as shown in FIG.
As shown in al, each half-cycle peak of the sine wave signal A is displaced from an inclination angle of 0° to an oblique direction of 45°, and from an oblique direction of 45° to an inclination angle of 0°.

As shown in FIG. 2(b), the control unit 13 controls the parallel plate 1
In synchronization with the displacement of 1, the accumulation signal B is output to the solid-state image sensor 5 during the period of the peak region of the sine wave, and the readout signal C is output during the other periods.

The solid-state image sensor 5 accumulates images with a displacement of 0° and a displacement of 45° at the timing shown in FIG. 2 (C1) in synchronization with the accumulation signal B and readout signal C shown in FIG. Continue posting images.

Further, as shown in FIG. 2(a), by displacing the parallel plate 11 in an oblique direction at 45 degrees with respect to the horizontal and vertical directions of the field of view, the solid-state image sensor 5 The light receiving part (1, 2, 3...9) of each pixel is diagonally 45
This is equivalent to moving to the insensitive parts (1', 2', 3', . . . 9) in the ° direction. In this way, 1, 2, 3, . 2', 3"...
Each pixel of 9' is sent to the image processing section 14.

The image forming unit 14 forms the remaining insensitive areas (a, b,
For example, in the case of a dead area e, calculate the average value of the pixels on its outer periphery as (2+2"+1"+5)/4 and use it as the pixel value of the dead area e. It is applied to the pixel to form one frame of image and display it on the display unit 4.

〔Example〕

FIG. 4 is a schematic diagram of a solid-state imaging device according to an embodiment of the present invention.

In FIG. 4, the solid-state imaging device of one embodiment includes a parallel plate 11 that transmits light between a condensing lens 2 that collects radiation from a subject 1 and a solid-state imaging device 5 that captures an image of the subject 1.
, a bimorph piezoelectric actuator 12 that drives the parallel plate 11 with a sine wave signal, and a bimorph piezoelectric actuator 12 that displaces the parallel plate 11 in a direction of 45 degrees with respect to the horizontal and vertical directions at every half-cycle peak of the sine wave signal, and drives the parallel plate 11 with a sine wave signal. The configuration includes a control section 13 that controls the storage in the solid-state image sensor 5 during the signal peak region period and the readout during other periods.

Further, the image processing unit 14 of one embodiment includes a first storage unit 15
, a calculation section 16 , and a second storage section 17 .

The scanning operation of this embodiment will be explained with reference to FIGS. 2 and 3.

The parallel plate 11 has its transmission surface perpendicular to the optical axis H (inclination angle of 0°).

In this way, the parallel plate 11 set at an inclination angle of O° is
The bimorph type piezoelectric actuator 12 allows the bimorph type piezoelectric actuator 12 to
As shown in al, each half-cycle peak of the sine wave signal A is displaced from an inclination angle of 0° to an oblique direction of 45°, and from an oblique direction of 45° to an inclination angle of 0°.

On the other hand, as shown in Figure 2), the control unit 13 synchronizes with the displacement of the parallel plate 11 and outputs the accumulation signal B during the period of the peak region of the sine wave and the readout signal C during the other periods. Output to element 5.

The solid-state image sensor 5 acquires M#1 of the images with a displacement of 0° and a displacement of 45° at the timing of FIG. 2(C) in synchronization with the accumulation signal B and the readout signal C of FIG. The image is then read out.

Further, as shown in FIG. 2(a), by displacing the parallel plate 11 in an oblique direction at 45 degrees with respect to the horizontal and vertical directions of the field of view, the solid-state image sensor 5 The light receiving part (1, 2, 3...9) of each pixel is diagonally 45
Dead area in the ° direction (1′, 2”).

This is equivalent to moving to 3'...9. 1, 2.3...9 and 1 detected by the solid-state image sensor 5 in this way.
', 2', 3', . . , 9' are sent to the image processing section 14.

In FIG. 4, 1, which is sent from the solid-state image sensor 5,
Each pixel of 2.3...9 and 1", 2'3'...9" is temporarily stored at a predetermined address in the first storage section 15,
After forming the pattern shown in FIG. 3, each dead area (a, b, c, . . .
pixel on the outer periphery of r), for example, 2.2" in the case of the dead area e.
, l”.

5 is read out and output to the calculation unit 16. The calculation unit 16 calculates the average pixel value by calculating (2+2'+1'+5)/4.

The second storage unit 17 stores the pixel pattern shown in FIG. 3 similarly to the first storage unit 15, and stores the average pixel value input from the calculation unit 16 in the corresponding dead area to eliminate the dead area. , the image is displayed on the display section 4.

As a result, four times as many pixels as the number of solid-state image sensors are obtained,
High resolution images can be obtained. Further, the bimorph piezoelectric actuator can easily perform minute displacements in a sinusoidal waveform, and is inexpensive and compact, resulting in higher resolution, smaller device size, and lower cost.

〔Effect of the invention〕

As explained above, according to the present invention, a bimorph piezoelectric actuator driven by a sine wave signal is used to obtain four times the number of pixels as the number of solid-state image sensors by scanning in only one direction, thereby achieving high resolution. This makes it possible to reduce the size and cost of the device.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the principle of the solid-state imaging device of the present invention, Fig. 2 is a diagram for explaining the scanning of the parallel plate of the invention and the operation of the solid-state imaging device, and Fig. 3 is an illustration of the scanning method of the invention. Fig. 4 is a schematic diagram of a solid-state imaging device according to an embodiment, Fig. 5 is a schematic diagram of a conventional solid-state imaging device, and Fig. 6 is a scanning diagram of a scanning optical system of a conventional solid-state imaging device. FIG. 7 is a drive voltage waveform diagram of the piezoelectric actuator. In the figure, l is the subject, 2 is the condensing lens, 3° is the signal processing unit, 4 is the display unit, 5 is the solid-state image sensor, 6 and 7 are the first and second filters, 8 and 9 are the first and 2nd piezoelectric actuator, 10 is a rotating shaft, 11 is a parallel plate, 12 is a piezoelectric actuator (bimorph type), 13
13-1 to 13-25 are pixels; 14 is an image processing unit; 15 and 17 are first and second storage units;
indicates a calculation section. Lee's decision was made in 1999, and the court ordered him to do so. Figure 1, Figure 2.
Fig. 4 Fig. 5 Fig. 6 (Q) An piezoelectric 77 controller, Chi'Yu's skin, Fig. 7

Claims (1)

[Claims] Condensing lens (2) that condenses the emitted light from the subject (1)
and a solid-state image sensor (5) that images the subject, and a parallel plate (11) that transmits light, and the parallel plate is rotated at an angle of 45 degrees with respect to the horizontal and vertical directions in half a cycle of a sine wave signal. Piezoelectric actuator (12) for displacing in the direction
and a control unit (13) for controlling the solid-state image sensor so as to perform accumulation during a period of a peak region of the sine wave signal and read out during other periods. Device.