JPS59852Y2 - solid-state imaging device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a solid-state imaging device in which a semiconductor imaging element is arranged in an imaging section.

CCD (charge-coupled structure (photodiode and MOS switch) one-dimensional or two-dimensional semiconductor image pickup devices (hereinafter referred to as sensors) have attracted attention as an alternative to conventional image pickup tubes due to their various advantages, and are already being used in industrial applications. It is beginning to be applied to the measurement field, OCS, facsimile, barcode readers, etc.

However, optical input devices using solid-state image sensors (
When using a camera (hereinafter referred to as a camera), dark current must be considered as a very important issue.

This dark current increases in a certain relationship as the sensor temperature rises or as the charge accumulation time increases, and it causes various problems when using the camera, such as a decrease in the camera's dynamic range or variations in the output level. becomes.

Further, when the above-mentioned sensor is applied to a camera used in the industrial field, the camera must be constructed to be dust-proof, and the camera has a sealed structure, so the temperature inside the camera increases considerably due to the heat generated by the electronic circuit.

To explain this regarding the conventional camera shown in Figure 1,
A lens system 1 is attached to a case 2 of a camera body, and components constituting an electronic circuit for processing video signals are mounted on printed circuit boards 3 and 4.

A CCD array (the above-mentioned sensor) 5 is arranged on the substrate 3 on the lens system 1 side.

In order to prevent temperature rise in conventional cameras like this, we simplified the electronic circuit inside the camera and used fewer parts.
In addition, the elements used were chosen to have low power consumption as much as possible.

However, these treatments also have limitations, and a temperature rise of about 20 to 30° C. relative to the outside air cannot be avoided, which increases the dark current by nearly 10 times, making it extremely difficult to handle.

The causes of such a rise in sensor temperature include: (1) The space temperature inside the camera rises due to heat generated by peripheral electronic circuits, and this rise is transmitted to the sensor.

■Heat generated from peripheral electronic circuits is transmitted to the sensor via the printed circuit board 3 and sensor lead wires.

■Due to self-heating of the sensor. It is possible that

Furthermore, FIG. 2 shows the sensor of the camera according to the present invention and the camera according to the present invention, which is an improvement of the conventional camera described above, in which the electronic circuit is mounted on the surface of the printed circuit board opposite to the surface on which the CCD is arranged. This is a graphical representation of the experimental results showing the difference in temperature rise of .

A indicates the temperature inside the camera, and the mouth indicates the outside temperature.

C is a temperature waveform showing the temperature rise of sensor 5, but even with this, the temperature of the sensor becomes almost the same as the temperature inside the camera approximately 30 minutes after the power is turned on to the camera, and the outside temperature When is a little high, it becomes almost impractical.

On the other hand, 2 shows the temperature rise of the sensor 5 when the present invention described below is implemented.

Therefore, the present invention proposes a structure that minimizes the influence of temperature rises inside the camera on the sensor, thereby creating a solid-state imaging device that uses a semiconductor imaging device (
The purpose is to expand the uses of cameras.

Embodiments of the present invention will be described above with reference to the drawings.

Figure 3 shows the camera body, whose front view is shown in Figure 4.
A sectional view of D is shown.

The lens system 1 and printed circuit boards 3 and 4 are similar to the conventional camera shown in FIG. 1, but the positions of the circuit components 10 and 11 are different.

The sensor (CCD array) 5 is packaged in a DIP type, but it is not mounted directly on the printed circuit board 3. A DIP socket 12 is mounted on the printed circuit board, and the sensor 5 is connected to this via a heat sink 13. It will be installed.

This heat sink 13 has the shape shown in FIG. 5, and is made of a material with excellent heat transfer properties, such as an aluminum plate.

In the center thereof, a notch 14° 15 is provided in the shape of an elongated hole, and when the sensor connection pin is inserted into this part and the sensor 5 is arranged in the shape of a chain line, the back side thereof will be in contact with the remaining part 16. It has become.

The heat of the sensor 5 transferred to the remaining portion 16 is transmitted to the outside through the entire heat sink 13 and radiated to the outside.

The front cover 17 to which the heat dissipation plate 13 is attached is also made of aluminum casting in order to enhance the heat dissipation effect, and its outer peripheral portion is formed with concavities and convexities so as to function as fins.

(See the G-0 sectional view of FIG. 4 shown in FIG. 6) Next, the relationship between the heat sink 13, the printed circuit board 3, and the sensor 5 will be mentioned.

The hot plate 13 is provided with screw holes 18 (Fig. 5),
This hole 18, screw 19, nut 20 and bush 21
The heat sink 13 and the printed circuit board 3 are integrated using the
Furthermore, a sensor 5 is mounted, and the three components are integrated into a case consisting of a front cover 17 and a cylindrical body 22.

And in order to fix this integrated part to the case, a sixth
As shown in the figure, a support 24 (the tip of which is a screw) passing through the printed circuit board 3 is used to create a hole 2 in the heat sink 13.
This is done by implanting the screws of the support column 24 through the screws 3 (FIG. 5).

Then, the printed circuit board 4 is placed on the other end of the support column 24 using screws 25.

Note that between the back surface of the sensor 5 and the portion 16 of the heat sink 13,
A heat diffusion compound is applied to the portion of the heat sink 13 in contact with the front cover 17 to improve heat conduction.

Further, 25 is a ring for attaching the lens system 1, and this is positioned by a lock rod 26 and a hexagon socket set screw 27, as shown in FIG. 7 (HI-I sectional view in FIG. 4). .

28 is a rear cover on which a connector 29 is arranged.

Via this connector 29, power is supplied to the electronic circuit from the outside and video signals are sent to the outside.

Note that 30 is an O-ring. Such a camera body is fixed to a support base 32 using screw holes 31 (FIG. 4).

In this way, in the present invention, when mounting a semiconductor image sensor (sensor) on a printed circuit board, a thermally conductive plate-like member is interposed so that the back surface of the image sensor package comes into contact with the member, and the member is Since we have adopted a structure in which it is extended and connected to the exterior of the camera body, the temperature rise of the semiconductor image sensor itself due to outside air is considerably suppressed, making it suitable for industrial solid-state image sensors that have to adopt a sealed structure due to poor surrounding environments. The influence of dark current can be considerably removed, and since the charge accumulation time can be extended accordingly, it can be used even when the amount of light from the subject is small.

As described above, according to the present invention, it is possible to considerably overcome the poor temperature characteristics of conventional solid-state imaging devices, and to considerably improve the limitations of their applications. The operation will also be stable.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the structure of a conventional camera, Fig. 2 is a diagram showing the temperature characteristics of the camera, Figs. 3, 6, and 7 are cross-sectional views of the embodiment device, and Fig. 4 is the embodiment device. The front view of FIG. 5 is a drawing showing the shape of the heat sink.

Claims (3)

[Scope of utility model registration request] (1) In a solid-state imaging device in which an imaging section is formed by a semiconductor imaging device and an electronic circuit for processing a video signal from the imaging device is also built into the camera body, the package for the semiconductor imaging device has a back side of the package. It is characterized in that it is arranged on the printer 1 to the substrate through a thermally conductive plate-like member that comes into contact with it, and that this plate-like member is extended and fixed to the exterior part of the camera. Solid-state imaging device. (2) The plate-shaped member is a large plate-shaped member having two rows of notches corresponding to the pin portions of the package in the center thereof, and the semiconductor image sensor package is printed through this large plate-shaped member. The solid-state imaging device according to claim 1, which is a utility model registered, and is connected to a socket mounted on a substrate, and the entire peripheral portion of the large plate-like member is in contact with the exterior portion. Device. (3) A utility model registration request for a structure in which the printed circuit board on which the semiconductor image sensor package, the large plate-like member, and the socket are mounted are assembled together, and this integrated member is incorporated into the camera body. range 2nd
The solid-state imaging device described in .