JPS62264022A - Image pickup device - Google Patents

Abstract

PURPOSE:To easily and surely perform a stable operation by providing actuators and providing a soft prism whose thickness is changed to have a gradient by the operation of these actuators. CONSTITUTION:Plural actuators 3-1-3-4 consisting of piezoelectric elements are arranged in the peripheral part to vary the vertical angel of a soft prism 1 by depression. The vertical angle of the soft prism 1 is varied to generate a gradient of refractive index, and light beams of picture elements 4-1-4-4 are minutely deflected and are inputted to an image pickup element 5, and the resolution of the image pickup element 5 is improved in image input by the picture element interpolating method. The angle of the soft prism 1 is successively changed in vertical and horizontal directions by actuators 3-1-3-4 to deflect light beams two-dimensionally. Plural picture elements 4-1-4-4 are successively taken in by the clock of the image pickup element 5 synchronized with the driving timing of actuators 3-1-3-4 and are inputted to a memory 7 to improve the resolution.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an imaging device, and particularly to an imaging device with increased resolution.

[Conventional technology]

Conventional methods for increasing resolution include a method that doubles the resolution by vibrating a solid-state image sensor by a half-pixel pitch using a piezo element, or a doubling method that utilizes birefringence to receive an image by overlapping two rows of pixels. There was a mechanism. However, in either case, the resolution in the - direction is only doubled. In addition, there are limitations to the piezo vibration cycle, and the method using a deflection plate has the disadvantage that the image receiving sensitivity of the W detector becomes poor. These conventional methods require many mechanical parts, are expensive, and require precision positioning and assembly. On the other hand, increasing the formation density of photoelectric conversion pixels in order to improve the resolution of the solid-state image sensor itself not only involves technical difficulties, but also involves deterioration of characteristics and a significant increase in cost.

[Problem that the invention seeks to solve]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an imaging device that solves the above-mentioned conventional drawbacks, has fewer components, can be operated reliably and stably using a simple method, and can easily achieve high resolution.

[Means for solving problems]

In order to achieve such an object, the imaging device of the present invention is characterized in that it is equipped with a soft prism in which a plurality of seven-piece units are disposed around the periphery and whose thickness changes to produce a gradient according to the operation of an actuator. .

[For production]

The present invention uses an actuator to change the apex angle of a soft prism at the input section of an image sensor with a finite aperture to create a refractive index gradient and minutely deflect the light beam of a pixel.
The 1-pixel interpolation method input to the M image element is used to increase the resolution of the image sensor during image input. For example, by arranging the actuator vertically and horizontally and changing the angle of the soft prism in the vertical and horizontal directions one by one.

Synchronized with the drive timing of this actuator, which performs two-dimensional light beam deflection! ! With the clock of the image element,
Capture all multiple pixels one by one and input them into memory.
Higher resolution is possible with the help of a bar.

〔Example〕

The present invention will be described in detail below with reference to the drawings.

[Example 1] In Figure 6 showing the first example of the present invention in Figure 1, l
2 is a soft prism made of a transparent elastic material such as silicone rubber or a transparent liquid such as silicone oil; 2 is a glass plate with a soft prism sandwiched between both sides;
3-1.3-2 and 3-3.3-4 press the apex angle of the soft prism with seven cutuators consisting of, for example, a piezoelectric element f to vary it. 4-1.4-2.4-3.4-4 is an optical pixel located in the form of a lattice point which is deflected by a soft prism and imaged on the image sensor T, and 5 is a pixel 4-1 to 4- 4 is a two-dimensional imaging device such as a CCD that forms an image, and a plurality of photoelectric conversion cells are arranged in rows and columns on this latent image device. 6 is an interface consisting of a shift register, etc., which allocates a plurality of interpolated pixel signals input to the image sensor 5 to corresponding addresses in the memory 7, and 7 is a large-capacity memory for storing the plurality of pixel signals, 8-1 to 8-1. 8
-4 is a driver that drives each of the actuators 3-1 to 3-4, and 9 is a driver that applies a driving voltage to the seven actuators 3-1 to 3-4 in the vertical and water directions in synchronization with the storage and readout timing of the image sensor. This is an oscillation circuit to be added.

FIG. 2 shows an example of a pixel input sample, where 5-1 is each photoelectric conversion cell of the image sensor 51, and 4-1 to 474 are 4 input samples that are sequentially input to each photoelectric conversion cell 5-1 of the image sensor 5 in this order. one optical pixel.

Figure 3 (A) is a top view showing the soft prism and 7 cutuators in Figure 1 at a distance of 231 m, and Figure 3 (B) is A-B of Figure 3 (A)! 0 which is a cross-sectional view along it
In the figure, IA is a holding member in the shape of a window frame, for example, which presses the piezoelectric elements 3-1 to 3-4 against the glass plate 2 and restricts their interlocking. Intersecting piezoelectric element soft prism l
The dimensional change in the thickness direction of the piezoelectric J: creates pressure on the soft prism l through the glass plate 2, causing a change in the thickness of the soft prism l. Specifically, it is preferable to have a structure that expands and contracts in the direction perpendicular to the plane of the paper in FIG. It suffices if it can be regulated to bring about change.

In the L configuration, the oscillator 9 generates, for example, the driver 8-1.
When a pulse is applied to drive the piezoelectric element 3-1, the glass plate 2 is pushed in the thickness direction, and the soft prism l has a prism shape with a thinner L portion and a uniform inclination in the Y-axis direction. As a result, a uniform refractive index is produced in the Y-axis direction.

The optical pixel 4-1 is then deflected and input to the photoelectric conversion cell 5-1 in the imaging groove f5. After accumulating the electrical signal corresponding to this pixel in the cell 5-1 for a predetermined time, the interface 6
At the timing of the 0th order stored in a predetermined location of the memory 7 via the 0th order, a pulse is applied to the driver 8-2, and the piezoelectric element 3-2 is driven. Then, the thickness of the soft prism 1 changes along the X-axis direction, and the pixel 4-2 is input to the photoelectric conversion cell 5-1 of the image sensor 5. Similarly, driver 8-
3°8-4 and sequential timing pulses are added, and the piezoelectric elements 3-3.3-4 are driven, resulting in one pixel 4-3.4
-4 is captured in synchronization with the clock timing of each l field consisting of storage and readout of the image sensor. In this way, four pixels are sequentially input to the image sensor one field at a time, photoelectrically converted, read out, and stored as pixel signals in the memory. The time required for deflection per pixel is approximately 20m5 due to the elasticity of the soft prism.
When 4 pixels are sequentially deflected using ec, the time required for deflection is about 80 m5 ec, and high speed and high resolution can be easily obtained.

[Embodiment 2] FIGS. 4 to 6 show the operation of another embodiment of the present invention. FIG. 4 is a timing chart of the capture clock of the image sensor, and pulse trains (A), (B), (( :).

(D) are piezoelectric elements 3-1.3-2.3-3.3 respectively
-4 drive pulse, pulse train (E) uses a variable pulse in two stages as a drive pulse for the piezoelectric element f, as shown in Figure 0, which shows a read clock pulse. A first-stage low voltage V1 is applied to the piezoelectric element 3-1 during time tl-t2, and the soft prism is slightly tilted as shown in FIG.
angle 0□), thereby creating a relatively small refractive index gradient and deflecting the pixel 4-1 shown in FIG.

Next, between t2 and t3, the pixel signals accumulated between t1 and t2 are read out and stored in the memory 7. This time t2
A second high voltage V is applied to the piezoelectric element 3-1 during ~t3.
2 (&2V+), the soft prism is tilted greatly as shown in the angle 02 shown in Fig. 5, a large refractive index gradient is generated, the pixels 4-5 are deflected, and the cell S of the image sensor is
-Input to t. The pixel signals accumulated between t2 and t3 are read out and input into the memory 7 between t3 and t4. In this way, the driving voltage of the 7 actuators at one location is switched to 2 stages, and this voltage is applied to the 7 actuators one after another, and in the next period, it is stored in the memory, so that the 4 actuators are used for 2 pixels at a time. A total of 8 pixels are input to one image sensor. As a result, eight pixels located in a lattice pattern as shown in FIG. 6 can be input to one image sensor and stored in the memory, so that eight-fold pixel interpolation can be achieved.

[Embodiment 3] FIG. 7 shows a third embodiment of the present invention. This embodiment has a sandwich structure in which a hexagonal soft prism is sandwiched between hexagonal glass plates from both sides.

By driving seven actuators such as piezoelectric elements located at 60° clockwise positions around the optical axis, pixel 1 in FIG.
3-1 to 13-6 are sequentially deflected onto each cell 13-7 of the image sensor. Then, a zero-order piezoelectric element 12-
A voltage is applied to the piezoelectric element 12-2 at a position rotated from 1 to 60 @ counterclockwise to input the pixel 13-3 to the image sensor. In this way, by sequentially applying voltage to the piezoelectric elements arranged at 60'' intervals according to the time chart shown in FIG.
1 pixel can be input, and 12-1 to 12-6 pixels can be input.
It is also possible to increase the resolution by seven times by cutting off the voltage to the cell 13-7 and inputting a non-deflected pixel to the cell 13-7 of the image sensor.

In the embodiments described above, the resolution is improved in both the vertical and horizontal directions, but it goes without saying that the resolution may be improved only in the -dimensional direction.

According to the present invention, the effect of masking in image processing, such as edge enhancement by differentiation, etc., can be achieved by pixel shifting. It can also be used as a two-dimensional beam shifter that provides maneuverability for 3rd and 5th order image processing operations such as masks and convolutions. Although piezoelectric JT- has been described as an example of the actuator, shape memory alloys, s1 strain elements, etc. can also be used. Furthermore, since the amount of light beam deflection can be variably controlled using a deflector made of a soft prism, it is also possible to make the resolution variable.

〔Effect of the invention〕

As explained above, according to the present invention, since a plurality of pixels are input to each image sensor I using a deflector consisting of four soft prisms, the resolution can be greatly improved.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating a first embodiment of the present invention. Figure 2 is a pixel arrangement diagram to explain 4x pixel interpolation, Figure 3 (A) is a plan view explaining the soft prism and 7 cutuators in detail, and Figure 3 (B) is a diagram showing the A-B line. 4 is a timing chart of actuator drive pulses and image sensor Glock pulses. FIG. 5 is a perspective view illustrating the inclination of the soft prism, and FIG. 6 is a pixel arrangement diagram illustrating 8x pixel interpolation. FIG. 7 is a diagram explaining another embodiment of the present invention, and FIG.
FIG. 3 is a pixel array diagram for explaining double pixel interpolation. FIG. 9 is a timing chart of drive pulses for the actuator and clock pulses for the image sensor. l...Soft prism 2...Glass plate. 3-1, 3-2, 3-3, 3-4...actuator, 4-1.4-2. ..., 4-8...
Pixel, 5...Image sensor, 6...Interface, 7...Memory. 8... Driver, 9... Oscillation circuit, 12-1, 12-2,..., 12-8... Actuator, 13-1.13-2. ...13-6・
...pixel. Figure 3 Figure 5 Figure 2, . 1. , . 8 Mu! xxxx x,, a32-4- w --=no ii 1
8° "'Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] An imaging device comprising a soft prism having a plurality of actuators disposed around its periphery and whose thickness changes to produce a gradient according to the operation of the actuators.