JPH0125277B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compact and highly reliable imaging device for color television using a solid-state imaging device such as a CCD.

In recent years, imaging devices such as color television cameras that use solid-state imaging devices such as CCDs and BBDs have been attracting attention. This type of device uses a dichroic prism, for example, to convert an incident light image into a green component G, a red component R,
The light is separated into blue component B and the optical image of each color component is captured by a solid-state image sensor.

However, solid-state imaging devices such as CCDs generally have a structure in which the CCD body, that is, a semiconductor chip, is mounted in a package such as ceramics, bonded, and then encapsulated, so even if it is installed on the light exit surface of the dichroic prism. However, it was not possible to substantially enlarge the imaging surface. Moreover, in order to enlarge the imaging surface, it became necessary to considerably increase the size of the entire device. Furthermore, in the case of a solid-state image sensor having a socket structure, it is difficult to position the image sensors corresponding to each color component, so it is easy to cause so-called color shift, and to correct this, a fairly large-scale adjustment is required. It required a mechanism. Therefore, it has not been possible to reduce the size and weight of the imaging device, and it has also been impossible to improve safety and reliability due to positional displacement caused by mechanical shocks.

The present invention has been made in consideration of the above circumstances, and its purpose is to provide an imaging device with a compact and lightweight structure that is free from unstable factors such as color shift and can obtain highly reliable and stable color image signals. The purpose is not to provide equipment.

That is, the present invention integrates a color separation prism that separates an incident light image into light images of predetermined color components and a plurality of solid-state image sensors. It is used to fix a chip, which is a solid-state image sensor. This provides a structure in which the chip itself is mounted, further improving the accuracy of the mounting position.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a basic schematic diagram of an imaging device according to the present invention. A light image of a subject 1 is incident on a dichroic prism 3 as a color separation prism via an imaging lens 2. Incidentally, the incidence of the above-mentioned optical image may be performed through a filter 4 for color correction etc. attached to the front surface of the imaging lens 2. The dichroic prism 3 has three blocks 3a, 3b, 3c.
At the interface between the first block 3a and the second block 3b, a first multilayer interference film that reflects blue B rays and transmits other rays is formed by vapor deposition. Further, a second multilayer interference film is deposited on the interface between the second block 3b and the third block 3c, which reflects red and R rays and transmits other rays. Due to the action of these first and second multilayer interference films, the light image incident on the dichroic prism 3 is separated into its respective color components, and therefore, the blue component exits from the light exit surface of the first block 3a. A light image of the red component is output from the light exit surface of the second block 3b, and a light image of the remaining color component, that is, the green component, is output from the light exit surface of the third block 3c.

Each of the blocks 3a, 3b, and 3c has a solid-state image sensor 5 such as a CCD on each light exit surface.
a, 5b, and 5c are fixed with their imaging surfaces aligned with the light exit surface, respectively. The dichroic prism 3 is optically designed so that each color-separated optical image is formed on each imaging surface of the solid-state imaging elements 5a, 5b, and 5c. The photoelectric conversion signals of the optical images captured by the solid-state image sensors 5a, 5b, and 5c are transmitted to amplifiers 6a and 6.
After being amplified to a predetermined level through channels b and 6c, the signal is led to a color encoder circuit (not shown) and output as a predetermined color television signal.

By the way, the solid-state image sensors 5a, 5b, and 5c are composed of CCDs having the following structure. That is, stripe-shaped electrodes having a width of, for example, 8 μm are arranged in parallel at intervals of 2 μm on a P-type silicon semiconductor substrate via an insulating film such as SiO ₂ , and an output gate is formed at the end of the electrode. Further, a plurality of channel stops are formed under the electrodes of the semiconductor substrate in a direction perpendicular to the direction in which the electrodes are arranged, and the output gate constitutes a shift register in the direction spanning each channel. Pixels are formed corresponding to each area divided by channel stops and striped electrodes, and charges accumulated in the potential wells of each pixel are transferred by a transfer clock applied to the electrodes. It's becoming like that. The operation of this CCD is well known, and its explanation will be omitted.

According to the imaging device having such a structure, the light image of the subject 1 is separated into light images of B, R, and G color components by the dichroic prism 3, and the light images are separated into light images of each color component of the solid-state image sensors 5a, 5b, and 5c. Since each light image is formed on each imaging plane, each light image can be captured satisfactorily. Moreover, the solid-state image sensors 5a, 5b, 5c are
Since the main body itself is fixed to the light exit surface of the dichroic prism 3, the device shape becomes very compact. Further, in this case, the solid-state image sensor 5
In the region where the semiconductor substrates constituting elements a, 5b, and 5c are mechanically stably held by dichroic prisms, they are extremely stable against vibrations and the like. Furthermore, since the structure does not use a package or a socket as in the prior art, a sufficient imaging area can be ensured, and the positioning with respect to the prism 3 can be easily performed, so problems such as color shift can be solved.
At this time, there is no need for a large-scale device for positioning, and the solid-state image sensor 5 is placed on the prism 3 once.
If a, 5b, and 5c are firmly fixed, there is no possibility of displacement due to vibration or the like. Therefore, it is possible to obtain stable color image signals with high reliability.

Next, as solid-state image sensors 5a, 5b, 5c
A manufacturing process for integrally fixing and forming the CCD on the light exit surface of the prism 3 will be described.

First, as shown in FIG. 2a, a P-type semiconductor substrate 11 is
A CCD is formed by disposing a plurality of striped transparent electrodes 13 in parallel at predetermined intervals with an insulating film 12 such as SiO ₂ interposed therebetween. As described above, the electrodes 13 have a width of 8 μm and are set at intervals of 2 μm. For example, every third electrode 13 is commonly connected, and three adjacent electrodes constitute one cell (pixel). Note that the figure shows one channel.
The semiconductor substrate 11 is divided into a plurality of channels by a plurality of channel stops in its width direction. A signal output gate formed by, for example, a junction is formed at the end of the electrode (not shown). A CCD with such a structure has the above electrode 1
3 is used as an imaging surface, and a transparent substrate 15 made of glass or the like is bonded to the imaging surface with an adhesive 14 as shown in FIG. 2B. Instead of this transparent substrate 15, a filter substrate having a predetermined color transmission characteristic may be bonded and formed. Thereafter, as shown in FIG. 2c, a predetermined adhesive 16 is applied to the surface of the transparent substrate 15, and as shown in FIG. Glue each. Therefore CCD
are fixed to each light exit surface of the dichroic prism 3 via a transparent substrate 15, and the solid-state imaging devices (CCD) 5a, 5b, 5c and the prism 3 are integrated here.

Now, the alignment of the CCD is as shown in FIGS. 3a to 3c.
The alignment marks 17a, 17b, 18, and 19 provided on the light exit surface of the prism 3 may be followed. That is, since the accurate dimensions of the semiconductor substrate 11, the transparent substrate 15, and the prism 3 are determined independently, it is possible to mark the desired alignment marks 17a, 17b, 18, and 19 with high precision. . Therefore, mark 17
The transparent substrate 15 is superimposed on the semiconductor substrate 11 of the CCD according to the steps a and 18b, and these are further superimposed on the light exit surface of the prism 3 to form marks 17a and 1.
8 and marks 17b and 19 overlap each other, the positional relationship between them can be accurately defined. Block 3a, 3
If performed on each of the light exit surfaces b and 3c,
By simply predetermining the position of the mark 18 on each light exit surface, the solid-state image sensor (CCD) 5a, 5
The positional relationship between b and 5c is set with high precision. Therefore, color shift will not occur in the color signal obtained by combining the signals of each color component obtained by the solid-state image sensors 5a, 5b, and 5c. In this way, it is possible to obtain a highly reliable, stable and high quality color image signal. Further, the above alignment can be easily performed, and thereby there is no problem such as complication of the manufacturing process.

Note that the outputs of the solid-state image sensors 5a, 5b, 5c are connected to the output terminals of the solid-state image sensors 5a, 5b, 5c and the transparent substrate 15 using, for example, a paste bonding method.
By connecting the lead wiring formed on the
It can be taken out from this lead wiring.

Now, in the above embodiment, a three-chip imaging device using three solid-state imaging devices 5a, 5b, and 5c corresponding to red, blue, and green components, respectively, was described, but the present invention is also applicable to a two-chip imaging device. For example, as shown in FIG. 4, a dichroic prism 21 consisting of two blocks 21a and 21b is used, and the green component of incident light is reflected at the interface between the blocks 21a and 21b, and the red and blue components of incident light are transmitted. A multilayer interference film is formed by vapor deposition. And the first block 21
A solid-state imaging device 22a for imaging the incident light of the green component is fixed to the light exit surface of the second block 21b via a transparent substrate, and a solid-state imaging device for imaging the incident light of the red and blue components is fixed to the light exit surface of the second block 21b. The element 22b is fixed via the color stripe filter 23. As shown in FIG. 5, this color stripe filter 23 includes, for example, a red transparent filter 23a and a blue transparent filter 23b each having a width of 10 μm.
These are arranged alternately. In this way, the image signal of the green component imaged by the solid-state image sensor 22a is converted into a time series via the amplifier 24a and outputted, and the image signal imaged by the solid-state image sensor 22a is led to amplifiers 24b and 24c. The red and blue components are separated and extracted, and then output. A color television signal is generated using image signals of each color component outputted from these amplifiers 24a, 24b, and 24c, respectively.

Even in such a two-plate imaging device, the solid-state imaging device is directly fixed to each color-separated light exit surface of a dichroic prism (color separation prism), so the device is compact and Lighter weight can be achieved. Moreover, as in the previous embodiment, the solid-state image sensor can be easily aligned and fixed in the correct position, so it does not cause color shift and is stable and highly reliable even against vibrations, etc. High quality color image signals can be obtained. The same applies to the previous embodiments, but since there is no need to adjust the position while monitoring a color image as in the conventional case, manufacturing is very simple and manufacturing costs can be reduced.

As described above, according to the present invention, since the imaging surface of the solid-state imaging device is directly fixed to the light exit surface of the color separation prism, it is possible to significantly reduce the size and weight of the device. Furthermore, since the solid-state imaging device is not packaged as in the conventional case, alignment can be performed accurately and easily, and the imaging area (area) can be set sufficiently wide. Furthermore, since the solid-state imaging device is reinforced by the prism, it is mechanically stable, and handling restrictions are relaxed, allowing for stable use. Furthermore, it has excellent effects such as easy adjustment and other manufacturing, and is suitable for practical use.

Note that the present invention is not limited only to the above embodiments. For example, not only a CCD but also a BBD or MOS type image sensor can be used as the solid-state image sensor. Further, the electrode structure may be determined according to various types, such as a two-phase clock type or an overlap type. Furthermore, instead of the transparent substrate provided on the imaging surface of the solid-state imaging device, a color filter having desired spectral characteristics may be used to ensure color separation and further improve color quality. In short, the present invention can be implemented with various modifications without departing from the gist thereof.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention;
Figures 2 a to c are diagrams showing the manufacturing process, Figures 3 a to c
4 is a diagram for explaining alignment, FIG. 4 is a schematic diagram showing another embodiment, and FIG. 5 is a diagram showing the configuration of a color stripe filter. 3... Color separation prism (dichroic prism), 5a, 5b, 5c... Solid-state imaging device (CCD), 11... Semiconductor substrate, 12... Insulating film,
13... Electrode, 14, 16... Adhesive, 15...
Transparent substrate, 21... Color separation prism, 22a, 2
2b...solid-state image sensor, 23...color stripe filter.

Claims (1)

[Claims] 1 Equipped with a color separation prism that separates an incident light image into light images of predetermined color components and guides each to a light image exit surface, and a predetermined number of semiconductor chips of solid-state image sensors, without packaging the semiconductor chips. , an imaging device characterized in that its imaging surface is fixed to each of the light image exit surfaces.