JP2001242311A - Method of assembling prism and prism block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To significantly reduce the hardening time of an UV-curing adhesive in the method of assembling prism blocks which constitute a color separation prism by using an UV adhesive. SOLUTION: Color glass 3, 5, 7 adhered to specified optical faces of prisms 1, 2 is joined with semiconductor pickup devices 4, 6, 8 with a sheet glass 9 having high transmittance for UV rays by using a UV adhesive 10. When the prisms are irradiated with UV rays while the optical axis of each prism is adjusted in this temporarily adhered state, the UV rays transmit the sheet glass 9 and efficiently cures the UV adhesive 10 coated on the adhering faces. Thus, the assembling time can be significantly shorten.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for assembling a color separation prism provided behind a camera lens and a method for extracting an image pickup signal of a video camera as a color signal obtained by dividing the image into three primary colors. Regarding the assembled prism block.

[0002]

2. Description of the Related Art Generally, in order to disperse light received by a camera lens using a color separation prism, it is necessary to assemble a plurality of prisms and optical components as a prism block. In the case of a video camera that outputs a color video signal using a semiconductor imaging device, a color separation prism is configured by three prisms and three optical filters to form a block, and the separated light is applied to the semiconductor imaging device. Output a signal. Since the assembling accuracy of the prism block affects the quality of the color signal, high-precision processing and precise assembling and adjustment are required. In particular, the assembly of the prism and the optical component needs to be performed in a short time from the adjustment to the bonding, and the prism block is assembled using a UV adhesive that is cured by ultraviolet irradiation.

FIG. 7 shows a conventional prism block assembling method. K1 ・ K2 prism 1 and colored glass (R)
5 and the color glass (B) 7 are assembled as an optical block first because optical adjustment is not required until the block is completed. Then, on this block, a color glass (G) 3 adhered to a K3 prism 2 and a semiconductor image pickup device 4
The semiconductor imaging device 6 and the semiconductor imaging device 8 are assembled while adjusting the optical axis in a state of being temporarily fixed by the UV adhesive. The semiconductor imaging device 4 is provided with a concave portion 12 a of the holder 12.
And the other semiconductor imaging devices 6 and 8 have the same configuration.

FIG. 8 shows a method of bonding the K1 / K2 prism 1 and the K3 prism 2, and a bonding surface of both prisms
After applying the V adhesive 10 and aligning the optical axes, the UV adhesive 10 is irradiated with ultraviolet rays 11 for curing. U
The V adhesive 10 is generally called an ultra violet adhesive, and has a property of being cured in a short time when irradiated with ultraviolet rays.

[0005]

However, in the above-mentioned conventional method of assembling a prism block, even if the prism block is irradiated with ultraviolet rays to cure the UV adhesive, the transmittance in the prism passes through 1 cm. 97%
Is absorbed inside, and only a small amount of ultraviolet light reaches the UV adhesive, and there is a problem that the UV adhesive does not cure for a long time. In particular, in the case of the above-mentioned prism block, when the spot is irradiated with ultraviolet rays and cured while adjusting the G axis, the R axis, and the B axis, a curing time of one hour per axis is required, and the three axes are required. There was a problem that it took 3 hours to cure the resin after adjusting the temperature.

SUMMARY OF THE INVENTION The present invention solves such a conventional problem. A prism assembling method capable of assembling a prism block in a short time using a UV adhesive and a prism assembling by this prism assembling method. It provides blocks.

[0007]

According to the prism assembling method of the present invention, a plate glass having a high ultraviolet transmittance is applied to a predetermined optical surface of a color separation prism having at least one prism.
It is characterized by joining with a V adhesive.
According to this method, the irradiated ultraviolet light passes through the plate glass and reaches the bonding surface, so that the U
The V adhesive can be efficiently cured, and the assembling time can be significantly reduced.

Further, the prism assembling method of the present invention is characterized in that the optical axis is adjusted while another optical component is temporarily bonded to the color separation prism with a UV adhesive. According to this method, since the UV adhesive is not cured unless irradiated with ultraviolet light, the optical axis can be adjusted while the UV adhesive is applied and temporarily bonded.

Further, in the prism assembling method according to the present invention, after adjusting the optical axis, the ultraviolet rays are irradiated from the end face of the plate glass without moving the position of the color separation prism.
V adhesive is cured. According to this configuration, since the ultraviolet energy can be effectively irradiated to the bonding portion from the end surface of the plate glass, the UV adhesive can be cured in a short time with less power than in the related art.
Further, since the ultraviolet irradiation is performed without moving the prism block for which the optical axis adjustment has been completed, a high quality prism block can be manufactured without displacement of the optical axis.

Further, the prism block of the present invention is bonded to a color separation prism having at least one prism and a predetermined optical surface of the color separation prism by a UV adhesive with a plate glass having a high ultraviolet transmittance interposed therebetween. And other optical components. With this configuration, an inexpensive, highly productive, high-quality prism block can be realized.

Further, the prism block of the present invention has at least one prism, a color glass adhered to a predetermined optical surface of the prism, and a plate glass having a high ultraviolet transmittance between the color glass. And other optical components joined by a UV adhesive. With this configuration, an inexpensive, highly productive, high-quality prism block can be realized.

Further, in the prism block according to the present invention, the other optical component is a semiconductor image pickup device. With this configuration, a small and lightweight prism block for a portable camera can be realized.

Further, in the prism block according to the present invention, the semiconductor image pickup device is disposed in a concave portion of the holder, and the plate glass seals a front surface of the semiconductor image pickup device in the holder. . With this configuration, the characteristics of the semiconductor imaging device can be stably maintained.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a method of assembling a prism block according to an embodiment of the present invention. For convenience of explanation, reference numerals used in FIGS. 7 and 8 for the conventional example are used for similar members. The order of assembling the prism blocks is as follows. First, color glass (R) is added to the K1 / K2 prism 1.
5 and the colored glass (B) 7 are adhered to each other.
A color glass (G) 3 is adhered to the substrate 1, and a plate glass 9 is further adhered to the K 1 / K 2 prism 1.
The sheet glass 9 is also adhered to each (via the holder 12). The glass sheet 9 has a transmittance of about 90% or more of ultraviolet rays. Then, the K3 prism 2 is placed on the plate glass 9 of the K1 · K2 prism 1, the plate glass 9 of the semiconductor imaging device 4 is placed on the color glass (G) 3 of the K3 prism 2, and the plate glass 9 of the semiconductor imaging device 6 is placed on the color glass (R) 5. Are bonded to a color glass (B) 7 by a UV adhesive 10, respectively.

FIG. 2 shows the prism block assembled in this manner. Simply applying and bonding the UV adhesive 10 does not cure the UV adhesive 10 unless it is exposed to ultraviolet light, so that each bonding surface can move in a temporarily bonded state. Therefore, the prism block is temporarily fixed on the jig, and the G axis 4a of the semiconductor imaging device 4, the R axis 6a of the semiconductor imaging device 6, and the B axis 8a of the semiconductor imaging device 8 are adjusted, and in that state, ultraviolet irradiation is performed. To finally fix.

FIG. 3 is a diagram for explaining the operation of irradiating the prism block with ultraviolet rays, and is an enlarged view of a portion A in FIG. The ultraviolet light 11 is applied to the semiconductor imaging device holder 1
2, the plate glass 9, the colored glass (G) 3, and the K3 prism 2. Since the semiconductor imaging device holder 12 is a resin molded product that does not transmit light, all the ultraviolet rays 11
Bounce back. In addition, since the K3 prism 2 has a transmittance of the ultraviolet rays 3 of 3%, the irradiated ultraviolet rays 11 are internally absorbed and attenuated. Further, the ultraviolet rays 11 incident on the color glass (G) 3 are not transmitted at all because the transmittance of the color glass (G) 3 is 0%, and are absorbed and attenuated inside. The ultraviolet transmittance of the colored glass (R) 5 is also about 0%, and the colored glass (B)
The ultraviolet ray transmittance of No. 7 is about 30%, which is almost untransmitted by ultraviolet rays. On the other hand, the ultraviolet transmittance of the glass sheet 9 inserted between the colored glass (G) 3 and the semiconductor imaging element holder 12 is as high as about 90%. Since the light passes through the inside and irradiates the bonding surface coated with the UV adhesive 10, the UV adhesive 10 is rapidly cured. The curing time is about 90 seconds per one hour per axis in the conventional curing time, and when curing while adjusting the three axes, it conventionally took three hours,
In this embodiment, it is completed in just over four minutes.

FIG. 4 shows a state in which the UV light is applied to the prism block in a state where the UV adhesive 10 has been applied and all the optical axes have been adjusted. Spotlight-like ultraviolet illuminators 13a, 1a installed at the optical axis adjustment location
A power supply 14 is connected to 3b and 13c to irradiate the end face of each glass sheet 9. Conventionally, as soon as the adjustment of one optical axis is completed, ultraviolet irradiation is performed and it takes time to cure the UV adhesive, but in the present embodiment, the time can be greatly reduced. Further, a small spotlight-shaped ultraviolet illuminating device 13a, 13b is provided at a position where the optical axis is adjusted.
By setting 13c, it is not necessary to move the prism block whose optical axis has been adjusted, and it is possible to prevent displacement after optical axis adjustment.

FIG. 5A shows a conventional joint structure between the colored glass (G) 3 and the semiconductor imaging element holder 12, and the colored glass (G) 3 is held in the concave portion 12 a of the holder 12. Although it also has a role of protecting the image pickup surface 4b of the semiconductor image pickup device 4, the color glass (G) 3 does not transmit ultraviolet light at all when bonded with the UV adhesive 10, so there is no reliability of bonding. Although the state of the adhesive surface of the UV adhesive 10 may not be uniform, in the present embodiment shown in FIG. 5B, the plate glass 9 is placed between the colored glass (G) 3 and the semiconductor imaging element holder 12. By intervening,
The UV adhesive 10 applied between the sheet glass 9 and the semiconductor image pickup device holder 12 causes the irradiated ultraviolet light to be applied to the sheet glass 9.
, The UV adhesive 10 cures and adheres in a short time, no air enters between the UV adhesive 10 and the UV adhesive 1
Since the deviation of 0 is unlikely to occur, not only the time can be shortened, but also the characteristics of the semiconductor imaging element 4 can be stably maintained by securely sealing the semiconductor imaging element 4. The other semiconductor imaging devices 6 and 8 are also held by similar holders (not shown), so that when they are bonded to the prism block, they are rapidly bonded with the colored glasses 5 and 7 and the plate glass 9 interposed therebetween. Confidentiality.

FIG. 6 is a flowchart showing another assembling sequence of the prism assembling method according to the present embodiment. First, K1
The color glasses 5 and 7 are respectively adhered and fixed to the R axis and the B axis of the K2 prism 1 (S1). Next, K2 prism 2
The colored glass 3 is bonded and fixed (S2). Next, the plate glass 9 is bonded and fixed to the surface of the K2 prism 2 opposite to the color glass 3 (S3). Next, a glass plate 9 is bonded and fixed to the imaging surface side of each of the semiconductor imaging devices 4, 6, and 8 (S
4). Next, a UV adhesive is applied to the respective joining surfaces of the K1 / K2 prism 1, the K2 prism 2, and the semiconductor image pickup devices 4, 6, and 8;
5). Next, the optical axis of the G axis is adjusted (S6). Next, G
After adjusting the optical axis of the shaft, the UV adhesive is cured in a short time by curing in an ultraviolet irradiation furnace or by ultraviolet spot illumination (S7). Next, after adjusting the optical axes of the R axis and the B axis, the UV adhesive is cured by ultraviolet irradiation (S8). Then, the optical block is completed (S9).

As described above, according to the present embodiment, the bonding of the prism block that splits light into three colors around the prism by the UV adhesive 10 is performed on the bonding surface with a high ultraviolet transmittance of about 90% or more. By inserting and bonding the glass sheet 9, the UV adhesive 10 on each bonding surface is irradiated with the ultraviolet rays 11 through the inside of the glass sheet 9, and the UV adhesive 10 is hardened at a high speed of about 90 seconds to complete the fixing. I do. Also,
Spot-shaped ultraviolet irradiation is possible at the position where the optical axis is adjusted, and the adhesive surface is cured while temporarily fixed on the jig with the adjusted optical axis, so that a stable, high-quality prism block is manufactured. can do.

In the above description, the K1 · K2 prism 1 and the K3 prism 2 are respectively colored glass 5
7 and 3 were adhered, and then fixed integrally with the semiconductor imaging devices 4, 6, and 8 by irradiating with ultraviolet rays while adjusting the optical axis, but the K1 / K2 prism 1 and the K3 prism 2
Each of the color glasses 5, 7, 3 and the plate glass 9 are bonded and fixed in advance, and a UV adhesive 10 is applied to the plate glass 9 and irradiated with ultraviolet rays while adjusting the optical axis to assemble the prism block. It may be.

[0022]

As described above, according to the present invention, the assembly of a prism block for extracting light of each color by splitting light is performed by sandwiching a plate glass having a high transmittance of ultraviolet light on each adhesive surface to which a UV adhesive is applied. UV light is radiated from the end surface of the glass sheet to spread the ultraviolet light to the bonding surface through the glass sheet to cure, so that the curing time of the UV adhesive can be greatly reduced and a stable, high-quality prism Blocks can be manufactured.

[Brief description of the drawings]

FIG. 1 is a partially assembled view of a prism block according to an embodiment of the present invention.

FIG. 2 is an assembly view of a prism block according to the embodiment of the present invention.

FIG. 3 is a schematic view showing the operation of the sheet glass in the embodiment of the present invention.

FIG. 4 is a schematic diagram illustrating a relationship between a prism block and an ultraviolet illuminator according to the embodiment of the present invention.

FIG. 5 (a) is a schematic diagram showing a state of bonding between a conventional semiconductor image sensor and colored glass.

FIG. 6 is a flowchart showing another assembling method of the prism block according to the embodiment of the present invention.

FIG. 7 is a semi-assembled view of a conventional prism block.

FIG. 8 is a schematic diagram illustrating a problem when a UV adhesive is used in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 K1 K2 prism 2 K3 prism 3 Color glass (G) 4 Semiconductor image sensor 5 Color glass (R) 6 Semiconductor image sensor 7 Color glass (B) 8 Semiconductor image sensor 9 Plate glass 10 UV adhesive 11 Ultraviolet 12 Semiconductor image sensor Holder 13 UV irradiation device 14 Power supply

Claims (7)

[Claims] 1. A prism assembling method, comprising: bonding a plate glass having a high ultraviolet transmittance to a predetermined optical surface of a color separation prism having at least one prism with a UV adhesive. 2. The prism assembling method according to claim 1, wherein the optical axis is adjusted in a state where another optical component is temporarily bonded to the color separation prism with a UV adhesive. 3. The method according to claim 1, wherein after adjusting the optical axis, the UV adhesive is cured by irradiating ultraviolet rays from an end surface of the plate glass without moving the position of the color separation prism. The described prism assembling method. 4. A color separation prism having at least one prism, and a predetermined optical surface of the color separation prism,
A prism block including another optical component bonded by a UV adhesive with a plate glass having a high ultraviolet transmittance interposed therebetween. 5. A color glass bonded to at least one prism, a predetermined optical surface of the prism, and a glass adhesive having a high ultraviolet transmittance interposed between the color glasses and a UV adhesive. Prism block with other optical components. 6. The prism block according to claim 4, wherein the other optical component is a semiconductor image sensor. 7. The prism block according to claim 6, wherein the semiconductor imaging device is disposed in a concave portion of a holder, and the glass plate seals a front surface of the semiconductor imaging device in the holder.