JPS6253578A - Solid-state image pickup device - Google Patents

Abstract

PURPOSE:To operate a device with low cost and low power consumption and without being equipped with a mechanical moving part and to reduce the effect of aberration remarkably by arranging a light deflector in the parallel light flux of an afocal image forming optical system between the focal plane of a photographing lens and a solid- state image pickup element. CONSTITUTION:An afocal image forming system is constituted between the image plane of the photographing lens and the solid-stage image pickup element and in its parallel optical path, the first optical member 1 consisting of a laminated structure in which a liquid crystal layer 11, a photoconductive film 16 and a dielectric mirror 14 are included is inserted. On the photoconductive film 16 of the first optical member 1, the distribution of the refractive index of the crystal layer 11 with in the first optical member 1 is constituted so that it can be changed linearly and spacially and also its inclination can be changed by the second optical member 2 which generates light intensity distribution having a linear inclination spacially and a means which can change the inclination of the light intensity distribution. The parallel light flux passing through the crystal layer, by the change of its advancing direction by the means and the change of its image forming position within an image forming plane, can generate the vibration of an image.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a solid-state imaging device used in a television camera or the like.

[Conventional technology]

Solid-state imaging devices have come to be used in a wide range of fields, including not only television cameras and VTR cameras, but also electronic still cameras, endoscopes, and various microscope monitors. Moreover, higher quality images are required in all fields, and higher density and larger number of solid-state image sensors are being pursued for this purpose.

However, at present, there is a limit to increasing the number of elements in solid-state imaging devices due to the sophistication of IC manufacturing technology and cost increases due to lower yields.

Therefore, as a conventional method for achieving high resolution using a solid-state image sensor with a limited number of elements, ('D) vibrate the lunar body of the solid-state image sensor with a pitch of I72 in the image plane. C,
By changing the inclination, the image is vibrated ■ A plane-parallel plate made of a material that has an electro-optic effect is placed tilted in the optical path, and the image is created by using the change in refractive index that occurs by changing the voltage applied to the material. Many proposals have been made, such as vibrating the

[Problem that the invention seeks to solve]

The conventional methods (1) and (2) require all mechanical movable parts, so they lack 4F;Ir1A properties, and (2) require all expensive crystal materials, and the operating voltage is generally high. There are drawbacks such as image quality deterioration due to various aberrations due to the insertion of a tilted medium into the optical path.

The present invention provides a solid-state imaging device that does not have any mechanically movable parts, operates at low cost and with low power consumption, and can achieve high resolution using a method with extremely little influence of aberrations.

[Means and effects for solving the problems] The present invention generally comprises an afocal imaging system between the image plane of an imaging lens and a solid-state imaging device, and in its parallel optical path, liquid crystal layer light, etc. ! The first layer consists of a multi/i5 structure including a film and a dielectric mirror.
Insert the optical member. Photoconductive film of the first optical member-EKs spatial KIili! a second optical member forming a light intensity distribution with a regular slope, and a means capable of changing the slope of the light intensity distribution; 7. It is constructed so that it is linear over time and its slope can be changed.

The parallel light beam that passes through the J period liquid crystal skin can be expressed as p by nq means.
By changing its traveling direction and changing its imaging position within the imaging plane, it is possible to cause image vibration.

〔Example〕

FIG. 1 is a diagram showing a first embodiment of the present invention. In FIG. 1, 1 is a first optical member containing liquid crystal, and a second optical member as a two-digit filter. 3 is an imaging lens, 4 is a planned focal plane of the same lens, 5 is an objective lens of an afocal imaging system, et'i polarizing plate, 2 is an imaging lens, and 8 is installed on the focal plane of the above lens. It is a solid-state image sensor.

FIG. 2 is a sectional view showing the M3 structure of the optical member 1 of the ff1l. In Figure 2, 1 is a liquid crystal, 12n is 12
hVi, internal dielectric layer arranged on both sides of the liquid crystal, I
,? a, 13h ij transparent electrode, 14 is a dielectric mirror, 15 is a light absorption layer, 16 is a light guide m film, 17m,
17b is a glass plate, 18 is a spacer, 19 is a transparent electrode r
sa, 13bK'fH connected AC power supply. In other words, the liquid crystal 11 is 12s, 13m gold laminated on the upper glass plate 1.
7m and a lower glass plate 17M in which 12b, 14, 15, 16.138'fc are laminated. One spacer 18 is entirely enclosed in a region.

Thus, when the control light 10 is not present, the light guide *BA16
Due to the diode effect and the capacitor effect of the dielectric mirror 14, the self-potential generated across the liquid crystal II is effectively zero regardless of the frequency and voltage of the AC power source. When the control light Iθ has a constant intensity, it becomes equivalent to a photoconductor with a low resistance of $ 1 i'i, so that a 1-noise difference occurs between both ends of the liquid crystal 11.

Assuming that the liquid crystal molecules are arranged parallel to the glass surface and the paper surface as shown in Figure 3 (al), when the external electric field E is 0, the controlled light that is polarized in the same direction as the alignment direction of the liquid crystal molecules. The refractive index of the liquid crystal 11 with respect to 20 is the refractive index r16 for extraordinary light.

When an external electric field E is generated, the external force polarizes the liquid crystal molecules and reaches saturation of about 1 Ft E, resulting in a state as shown in Figure 3 (C), and the refractive index of the liquid crystal becomes equal to the refractive index n0 for ordinary rays. . At an intermediate potential El, it is in the third iJ(b) state, and its refractive index nI is no < n 1 < n
It changes within the range of e.

W, Figure 4 (lIl (b) is a diagram showing the second optical member 2. The second optical member 2 is as shown in the prisoner (a) K, and the same tg (bl). As shown, this is a filter with an intensity transmittance distribution that changes linearly in the buying direction.

In the first embodiment configured in this way, when illumination light 9 of uniform brightness from a light source (not shown) passes through the filter 2, the nitrogen IV1 intensity distribution of the control light 10 is as shown in FIG.
a], and due to the conversion process of light intensity → external electric field → refractive index, the refractive index distribution of the liquid crystal 11 included in the first optical member l becomes as shown in FIG. It has a certain slope.For such a medium n(X), as shown in Figure 6 (
As shown in bl, when a parallel ray is incident, the optical path A -A'-Δ'' of the ray I in the medium and the optical path B n of the ray n
/-B11, an optical path difference approximately directly proportional to the distance ^-B occurs. Therefore, the outgoing rays are almost parallel and at a smaller angle θ than the incident ray.

It emits light.

When the intensity of the uniform illumination light 9 increases, the intensity distribution of the control light IO becomes as shown in FIG. Mochi, rays [and■
θ because the optical path difference in the liquid crystal increases. becomes even smaller.

As is clear from the above explanation, the imaging lens 3 in FIG.
It is possible to move the image 1←b on the image sensor surface 8 by uniformly changing the intensity of the illumination light 9! -Kill.

? - If it is assumed that the orientation direction of the polarized light of the polarizer 5 and the liquid crystal molecules in the absence of an electric field are both the X direction in FIG. 1, and that the rotation of the liquid crystal molecules due to the electric field occurs within the yz plane,
The refractive index distribution of the liquid crystal 11 for incident light does not depend on the incident angle.

Next, a second embodiment will be explained.

In the previous embodiments, the transmittance distribution of the second optical member was set in the X direction in Figure @1, so that the fixed position of the light spot was performed within the area of the same figure.

If the transmittance distribution of the second optical member 2 is linear with respect to y1 in the same figure, the scanning direction of the beam is perpendicular to the paper image (y100 ].

Therefore, in this embodiment, a second optical member as shown in FIG. 7 is used. That is, 21 and 22 are filters similar to those shown in FIG. 3, except that 2I has a transmittance distribution in the X direction in the figure, and 42 has a transmittance distribution in the X direction (perpendicular to the plane of the paper). Uniform illumination light 91.degree. 92 is incident on each filter independently by a light source and a frimeter lens (not shown). 9 and 92 are combined by the half mirror 23, and become the control light 10 having an arbitrary intensity gradient with respect to the X-y plane.
The light 4i of the optical member 1! The I film is irradiated.

Therefore, in this embodiment, by controlling the intensities of the uniform illumination lights 9 and 92, it is possible to scan the beam two-dimensionally on the plane 8.

Further, if 23 in FIG. 7 is a polarized beam splinter and 91 gold and 92 gold are linearly polarized lights that are orthogonal to each other, the utilization efficiency of illumination light can be improved.

In the above explanation, a device with laminated liquid crystal and a light guiding film was used as the first optical member, but materials such as B, 8.0, which have both photoconductive and electro-optic effects, are also used. Any device can be applied as long as it can simultaneously realize the functions.

〔Effect of the invention〕

According to the present invention, when trying to increase the resolution of an imaging device using a solid-state imaging device with a limited number of elements beyond the number of elements of an all-solid-state imaging device, it is possible to operate at low cost and with low power without worrying about all the town moving parts, and to avoid aberrations. It is possible to realize a system in which the influence of

Furthermore, the present invention is a method that can be expanded to two dimensions extremely easily.

[Brief explanation of drawings]

Are Figures W1 to 6 the first embodiment of the present invention? 1 is a diagram showing the overall configuration, FIG. 2 is an lfr side view showing the structure of the 2gl optical member, FIG. 3 (al to (C) is a diagram showing the function 2 of the same member, Figure 4 (at (b) i is a diagram showing the second optical member, WJs diagram and 'i'E6 diagram (,1
) (b) is an explanatory diagram of the operation, and FIG. 7 is a diagram showing other embodiments of the present invention. 1... First optical member, 2... Second optical member, 8
...Image sensor. Figure 1 20th Figure 2 Figure 7 □, 6Q, 10.1FJ7,. Commissioner of the Japan Patent Office Uga Michi nt j Yaku1, Indication of the case Patent application No. 60-194138 2, Name of the invention Solid-state imaging device 3, Person making the amendment Relationship to the case Patent applicant name (037) Olympus Optical 2 [Industry] Co., Ltd. r14
, agent

Claims (2)

[Claims] (1) A first optical member whose spatial distribution of refractive index for a component polarized in at least one specific direction of the controlled light changes according to the spatial intensity distribution of the control light, and the control over the first optical member. An optical deflector having a second optical member capable of making the spatial intensity distribution of light spatially linear, and a means capable of changing the slope of the spatially linearly distributed light intensity by the second optical member, A solid-state imaging device characterized in that it is disposed in a parallel light beam of an afocal imaging optical system configured between a focal plane of a photographing lens and a solid-state imaging device. (2) The second optical member is arranged to have a means for synthesizing the transmitted light beams of filters having inclinations perpendicular to each other, and to use the synthesized output light as control light for the first optical member. Claim 1 characterized in that
The solid-state imaging device described in .