JPS5863279A - Color image pickup device - Google Patents

Abstract

PURPOSE:To improve the quality of a reproduced picture, by bending a flexible spacer to control the relative position between the light output face of a color separating prism and a solid-state image pickup element and maintaining the bending of the spacer with the hardening of an adhesive. CONSTITUTION:A flexible spacer 30 is provided between the light output face of a color separating prism and a solid-state image pickup element. The spacer 30 is made of a metallic thin plate or a plastic thin plate for example and has a frame-like form. Furthermore each side of the frame of the spacer 30 has a recessed section. The prism is fixed to a measuring instrument board, etc., and the image pickup device is held by a control tool. Then the spacer 30 is held between the prism and the image pickup device. The spacer 30 is then bent to perform the control of position for both the direction of an optical axis and the direction rectangular to the optical axis. Then the bending of the spacer 30 is fixed by an adhesive 35.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color imaging device using a color separation prism as a color separation optical system and a solid-state imaging probe as an imaging means.

Color imaging devices using image pickup tubes as imaging means have been put to practical use in a wide variety of formats, such as single-tube, two-tube, and three-tube types. However, recently C0D1BBD, MOB
2. Description of the Related Art So-called solid-state image sensing devices, in which a light sensor with a signal transfer function such as a mold is configured in the form of a face plate, are beginning to be used as an imaging means in place of conventional image pickup tubes. These solid-state imaging devices are superior to image pickup tubes in terms of power consumption, lifespan, weight, and earthquake resistance, and if you combine these solid-state imaging devices with a mosaic color filter, you can create a color separation optical system. Tsujigashi is compact and lightweight as a single-chip color imaging device for parts stores that does not require registration adjustment. Even with a color imaging device, the image quality of the reproduced image, such as sensitivity, resolution, and color reproducibility, is excellent.
A force 2-imaging device with more than one plate, preferably three or more plates will be used.

FIG. 1 is a diagram illustrating the principle configuration of an example of a three-plate color imaging device, in which a light beam from a photographing lens 1 is made incident on a color separation prism 2, and red and red are separated by the color separation prism 2.
The light is received by solid-state imaging devices 3R13G and 3B installed for each color channel of green and evening light.

By the way, the relative positional relationship between the light emitting surface of each color channel of the color separation prism 2 and the light receiving surface of the solid-state imaging probe must be determined by taking into account focus adjustment for each color channel and registration adjustment between each channel. It won't happen. In order to make such adjustments possible, various methods have been proposed, such as attaching each solid-state imaging probe to a single substrate to which the color separation prism is fixed, or to a mounting via an adjustable holding mechanism. However, this method has drawbacks such as the imaging device itself having a complicated holding mechanism built in, and the need for dust-proofing measures between the light exit surface of the color separation prism and the solid-state imaging probe. . On the other hand, a method in which the solid-state image sensor is fixed to the light exit surface of the color separation prism after performing focus adjustment and registration adjustment in advance, only requires fixing the color separation prism to the camera board, so the camera itself The structure is also simplified, and it is very advantageous in terms of compactness and light weight.
It is also easy to take dust-proof measures. The simplest method is to use a transparent adhesive to directly adhere solid-state imaging probes to each color light exit surface of a color separation prism. In this case, even if the position and tilt adjustment (registration adjustment) in a plane perpendicular to the optical axis of each color channel can be adjusted using an adjustment jig, one adjustment in the optical axis direction (registration adjustment li) may be possible.
Focus adjustment Ii) is not possible. However, this adjustment in the optical axis direction is absolutely necessary because there are limits to the manufacturing accuracy of the color separation prism and the accuracy of the solid-state imaging probe package (the optical path length sheath from the outer surface of the solid-state imaging probe to the light-receiving surface). Considering this point, for example, as shown in Fig. 2, the light exit surface 21 of the color separation prism and the solid-state camera
, and the first child 23 may be interposed with a spacer 22. In this case, for example, use an adjustment jig or the like to perform tilt adjustment 1i (registration adjustment) in the X-axis, Y-axis directions, and around the two axes in the figure, and then measure the amount of adjustment in the two-axis directions. After obtaining the quantitative value and determining the spacer thickness based on this, the adhesive fixing work is performed. However, such work requires two stages of adjustment, and in addition, the thickness of the spacer itself differs depending on the color separation prism in the direction of the optical axis.
The reality is that it is not very practical because it has many drawbacks such as the accuracy of the spacer thickness itself, and it is difficult to obtain an excellent performance as a color imaging device.

SUMMARY OF THE INVENTION In view of the prior art as described above, an object of the present invention is to provide a color imaging device having a structure that facilitates adjustment work (1) and provides sufficient adjustment accuracy. In the color imaging device of the invention, a flexible spacer is interposed between the light exit surface of the color separation prism and the solid-state imaging device fixed thereto.Focusing is performed by bending this spacer. , enables the position adjustment of the solid-state imaging probe such as registration, and furthermore, after adjustment, the adhesive to fix the relative position of the prism and the solid-state imaging device is supported by a spacer, and the flexible deformation state is controlled by the hardening of the adhesive. Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 3 is an example of a flexible spacer applied to the color imaging device of the present invention. This spacer is made of a flexible material such as a thin metal plate or a thin plastic plate, and has a frame shape as shown in the figure. This shape is intended to prevent the spacer from blocking the light flux emitted from the light exit surface of the color separation prism. Further, this spacer has a frame shape with each side having a concave cross section. To adjust and fix the solid-state image sensor to the light exit surface of the color separation prism using such a spacer, first fix the prism to a measuring instrument surface plate, etc., hold the solid-state image sensor in an adjustment jig, The spacer is inserted between these, and the position and rotation in the direction of the optical axis and in the direction perpendicular to the optical axis are adjusted while bending the spacer, and then they are bonded together with an adhesive. For this bonding, it is necessary to put an adhesive 30 into the recessed portion of the spacer 30, as shown in FIG. 4, and to fix and maintain the spacer's deflection by hardening the adhesive. Therefore, as the adhesive used for this, a silicone rubber adhesive (for example, known as RTU60 manufactured by G1 Company), etc., whose shrinkage during curing is negligible, is suitable. If a transparent adhesive is used, an appropriate opening may be provided in the spacer and the space 40 in FIG. 4 may be filled with the adhesive through the opening. However, in this case, care must be taken to prevent air bubbles from getting into the adhesive. When the bonding work is completed in this way, these are removed from the v4!1 jig, etc.

The light exit surface of the color separation prism or the surface of the solid-state image sensor is required to be clean because it is close to the image formation surface. Therefore, it is preferable to keep this part sealed to prevent dust.
As shown in the figure, the spacer is shaped like a frame and covers the entire outer edge of the light exit surface of the prism to prevent this.
This will also solve the problem.

FIG. 5 shows another embodiment of the present invention, in which a solid spacer 51 (for example, the spacer 22 in FIG. 2) is bonded to the light exit surface 54 of a color separation prism 50, and this solid spacer 51 and solid-state imaging A flexible spacer 52 having a concave portion in the opposite direction to that shown in FIG. 3 is sandwiched between the element 55 and the element 55.

In this way, if the solid spacer 51 is used in combination, even if the flexibility range of the flexible spacer 520 is exceeded, the same flexible spacer can be used. Note that 53 is an adhesive for maintaining the flexible position of the flexible spacer and for adhesively fixing them.

FIG. 6 shows still another embodiment of the present invention, in which 't=
This is an example in which a porous elastic material such as a porous material is used as the flexible spacer 61.

After setting the spacer, an adhesive is injected into the spacer and impregnated, and the adhesive is cured at that position to maintain the shape.

In this way, the color imaging device according to the present invention uses a flexible spacer as a spacer, which makes it easier to perform focus adjustment, which was difficult in the past, and the adjustment can also be changed continuously. As the color separation prism
The manufacturing precision of solid-state imaging device packages and the like is relatively more permissible, making manufacturing easier. Furthermore, if the accuracy of the color separation prism and solid-state image sensor is relatively good, and the adjustment range of focus and registration is within the flexible range of the flexible spacer, then attach it to the adjustment jig. These are glued together beforehand (in some cases, a solid spacer may also be used together).Then, the spacer is flexed using an adjustment jig to adjust focus and registration, resulting in a 70-degree flexible state. It is also possible to use a work process in which the adhesive is used to maintain the hardening. Note that the spacer used in the present invention basically has a spacer that is sandwiched between the light exit surface of the color separation prism and the surface of the solid-state image sensor and has a readability (may have elasticity),
This is said to be solidified by the adhesive in the deformed state after y4f, and its shape is not necessarily as in the example (although it may be good, if you take into account prevention 1 or adhesive protrusion, etc.) Preferably, as in the illustrated embodiment, the adhesive is supported by a spacer arranged under the external pressure of the effective light beam.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the basic configuration of a general three-plate color imaging device. FIG. 2 is a perspective view showing the structure of a conventional color imaging device in which a solid-state imaging cable is attached. FIG. 3 is a perspective view showing an example of a flexible spacer used in the present invention. FIG. 4 is a principle diagram showing the structure of the spacer shown in FIG. 3 and the attachment of the solid-state imaging cable used therein. 5 and 6 are principle diagrams showing other embodiments of the present invention, respectively. 21... Light exit surface, 22... Spacer, 23...
Allobody imaging cord, 3o...readable spacer, 35...
Adhesive, 51... Solid spacer, 52... Flexible spacer, 53... Adhesive, 61... Flexible spacer. Applicant Fuji Photo Hikane Co., Ltd. Figure 7 δJ Figure 4

Claims (3)

[Claims] (1) Force in which a spacer is sandwiched between the light exit surface of the color separation prism and the solid-state imaging element and these are adhesively fixed with an adhesive 2 - In the image sensor, the spacer has flexibility, and Use this spacer to adjust the relative position between the light exit surface of the prism and the solid-state image sensor!
! A color imaging device characterized in that the deflection of the spacer during the adjustment is maintained by curing of the adhesive. (2) The flexible spacer has a frame shape that does not block the effective light beam emitted from the separation prism, and the space surrounded by the light exit surface of the color separation prism, the solid-state image sensor, and the spacer is sealed. A color imaging device according to claim (1). (3) Claim #! characterized in that the adhesive for maintaining the spacer in the deflected position is a silicone rubber adhesive. (1) or (2)
'fA color imaging device.