JPH0354976A - Infrared ray image pickup device - Google Patents

Abstract

PURPOSE:To reduce the power consumption of a solid image pickup element and to compact its cooling means by impressing a driving pulse and a bias voltage to the solid image pickup element only for the effective scanning period of an optical scanning period and stopping the supply of the driving pulse and bias voltage during the residual scanning period to hold the element at a fixed voltage. CONSTITUTION:The solid image pickup element 13 having a self-scanning function in one direction is constituted of a charge transfer element 12 and plural infrared ray receiving elements 11. An optical scanning means 14 executes optical scanning in the direction rectangular to one direction to be the array direction of the elements 11 and makes light from an object whose image is to be picked up incident upon the elements 11 and a control means 15 supplies charge transferring driving pulse and a bias voltage to the elements 13 only for the effective scanning period out of the optical scanning period of the means 14 and stops the supply of the driving pulse and bias voltage during the blanking period to be the residual scanning period to hold the element 13 at the fixed voltage. Consequently, the power consumption of the solid image pickup element 13 can be reduced and the solid image pickup element cooling means is made compact.

Description

[Detailed description of the invention] (Ft required) Infrared va using a solid silver image element with self-scanning function
Regarding image devices, the power consumption of solid-state decoy image elements is reduced, making them solid-state! ! il
& With the aim of making the element cooling means smaller and cheaper, the {g charges obtained by nine-electron conversion using multiple infrared receiving elements f arranged in one direction, are transferred by charge transfer. Self-running in one direction with N product and transfer using elements! In an infrared PJ method in which an optical scanning means optically scans a solid body having an in-capacity in a direction orthogonal to the one direction to input light from an imaging target, the optical scanning means The initial pulse for charge transfer and bias voltage are applied to the solid-state decoy image element only during the effective scanning period of the optical scanning period, and the supply of the driving pulse and bias voltage is stopped during the blanking period which is the remaining scanning period. Be sure to include a control means to maintain a constant voltage.

[Industrial application field]

The present invention relates to an infrared imaging device, and more particularly to infrared 1a mold imaging using a solid-state Wi image element having a self-scanning function.

Prisoner imaging in which the charges obtained by photoelectrically converting the infrared light from the image carrying object using a plurality of infrared light-receiving elements arranged in one direction are injected into a charge-coupled device (COD) and then transferred and read out. @Element is one-dimensional IRCCD (l nfrared C
It is called a harge coupled device). Infrared $11i imaging using this one-dimensional IRCCD is being widely applied in the industrial field because it can accurately grasp the temperature distribution of the imaged object.

In the above-mentioned infrared imaging device, in order to accurately detect the temperature of the object to be imaged, a cooling means having a high cooling performance capable of cooling the IRCCD to a temperature of 80K is required. Therefore, in order to downsize the infrared imaging device, it is necessary to downsize the cooling means.

[Prior Art] FIG. 5 shows a configuration diagram of an example of a main part of a conventional infrared 164 imaging device n. In the figure, 51 is a detector container, inside of which are a bottom diode array (PV array) 52, a CCD 53.
A one-dimensional RCCD consisting of a MOS field effect transistor (FET) 54 as a source follower at the final stage is built-in. The PV array 52 has a configuration in which a plurality of photodiodes, which are infrared detection lines f, are arranged in one direction, and the output Jta of each photodiode is connected to the CCD 53.

Further, the source of the FET 54 is grounded via a load paper resistor 55 provided outside the detector 51, while the source of the amplifier 54 is grounded via a load paper resistance 55 provided outside the detector 51.
6 is connected to the human power terminal.

Reference numeral 57 denotes a refrigerator, which is provided to cool the {RCCD inside the detection organ 51. Note that the reason why the load resistor 55 is provided outside the detector container 51 is that if the load resistor 55 is provided inside the detector container 51, the heat generated by the negative r# resistor 55 is also cooled by the refrigerator 57. This is because the cooler 57 needs to have higher cooling performance, resulting in increased power consumption.

The imaging object is scanned in a direction perpendicular to the longitudinal direction of the PV array (photodiode arrangement direction) by an optical scanning means such as a mirror or a scanner, and the light from the scanned IT object is received by the PV array 52. Ru. The PV7 ray 52 charges and converts the incident infrared light, and transfers the obtained signal charge to the CCD 53.

COD53G. One input signal charge is sequentially transferred toward the FET 54 in synchronization with the input drive pulse, and at the final stage, the charge is converted into a voltage and applied to the gate of the FET 54. As a result, the voltage generated across the load resistor 55 is outputted to the signal processing circuit (f in the figure) through the amplifier 56.

Here, as shown in FIG. 6, the main power consumption generating parts inside the detector container 51 are the transfer section by the CCD 53 and the source follower FET 54.
．． A t4 phase clock (drive pulse) is applied separately to the corresponding transfer electrodes 58 to 584, respectively. Four transfer voltages Ni5 8 + to 584 are provided corresponding to one photodiode. That is, four transfer electrodes are provided corresponding to each photodiode of the Pv7 ray 52.

The four-phase clocks φ1 to φ4 are as shown in FIG. 7(C),
If the PV array 52 is made up of Mill photodiodes, the driving pulses have different partner phases by 909, and are outputted M times each to transfer the charge for one Norem (in other words, in the vertical direction). Transfer of signal charges of all M photodiodes arranged in a random manner is performed.

Set 1 corresponding to the final stage photodiode shown in Figure 6.
When the drive pulse φ4 to the transferred electrode 584 is reduced to the first potential, the signal charge 63 accumulated in the well of the conductive substrate directly below the transfer electrode 584' is reduced to the first potential. As φ4 changes to the second potential, the potential directly below the transfer electrode 584' changes to the broken line 64.
Since the voltage has been raised as shown in , it is input to the output gate (OG > 59 through directly below it) of a constant potential 65 (spreading diffusion m < floating diffusion) 60 , where it is converted into a voltage and then applied to the gate of the FET 54 . Ru.

At this time, the FET 61 is turned off.

The FE device 61 passes through the diffusion layer 60 directly under the output gate 59.
The pulse φR is applied before the next bit of charge is input to
It is turned on and the charge in the diffusion layer 60 is dumped into the semiconductor substrate via the FET 61, and then it is turned off again to prepare for inputting the next bit of signal@charge to the diffusion 1ff60.

Incidentally, FIG. 7(A) shows the characteristics of the scanning angle with respect to time of the above-mentioned optical scanning means, and the circumference is 1n. indicates that optical scanning is performed in the horizontal direction. Also, the same figure (B
) shows the relationship between the frame time of the CCD 53 and the optical scanning period 0, and each period T+ . Tz is blanking W that does not contribute to imaging
The remaining linear period ゜a is an effective scanning period for imaging, which is N frame time.The effective scanning rate η is expressed as Ta/Tb.

By the way, inside the detector container 51, as shown in FIG. 6, the CCD 53 consumes power P+ expressed by the following formula P1-K-f-C-V12 (1), and F E -r54
The power P2 represented by the following formula Pz-1z ・Vz (21 is consumed. Therefore, the power consumption Pot inside the detector container 51 is P(+-PI + P2 = K・'・C-V+2+L・It becomes V2G3.

[Problem to be solved by the invention]

However, in the infrared Ii imager, the above transfer electrode 1
Conventionally, power consumption is large because 1C is a person and the transfer frequency f has also tended to increase due to the increase in the number of pixels in recent years. Therefore, conventionally, the refrigerator 57 is required to cool down to about 80K, and the device size is large.
Another drawback is that it requires an expensive, high-performance refrigerator.

The present invention has been made in view of the above points, and an object of the present invention is to provide an infrared I1 imaging device that can reduce the power consumption of a solid-state electromechanical element, thereby making the solid state me element cooling means smaller and cheaper. The purpose is to

[Means to solve the problem]

FIG. 1 shows a basic configuration diagram of the present invention. In the figure, numeral 11 indicates infrared light receiving elements, and a plurality of them are arranged in one direction. Reference numeral 12 denotes a charge transfer element, which together with the infrared light receiving element 11 constitutes a stationary image element 13 having a self-scanning function in one direction.

14 is an optical scanning means, and the array 1 of the infrared light receiving elements 11 is
Optical scanning is performed in a direction perpendicular to one direction, and the light from the image carrier is made incident on the infrared receiving element r11. Reference numeral 15 denotes υtW means, which supplies charge transfer drive pulses and bias voltage to the solid-state llil image element 13 only during the right-handed scan I1 of the optical scanning period of the optical scanning means 14, and supplies the charge transfer drive pulse and bias voltage to the solid-state llil image element 13 during the blanking period which is the remaining scanning period. Then, the supply of the initial pulse and bias voltage is stopped, and the electric current is maintained at a constant level.

[Effect]

The optical scanning means 14 scans in a predetermined direction with an optical scanning circumference MTO as shown in FIG. 2(A). Conventionally, this optical scanning period ``O'' has not only the effective scanning 19'1 interval a, but also the blanking period T+ .T,! which is unrelated to image output.
As shown in FIG. 7(C), the transfer drive pulse φ1~
φ4 and bias voltage were applied to the blanking period and the element respectively, but the present invention focuses on this blanking period r1 and applies control II.
If stage 15 is used as shown in FIG. 2(B). As shown in (C),
During the planning period, the transfer drive pulses φ1 to φ4 and the bias voltage are held at constant voltages (for example, OV).

As a result, the power consumption of the solid state image element 13 is consumed only during the effective scanning period Ta, and during the blanking period ('
ro Ta), the transfer frequency f is 0 and the source voltage v2 is O, so from the above equation 0, the power consumption P of the present invention is expressed by the following equation.

That is, according to the present invention, the power consumption can be reduced compared to the conventional Ta/T.
This means that it can be reduced by o times.

〔Example〕

FIG. 3 shows a configuration diagram of an embodiment of the present invention. In the figure, the same components as in FIG. 1 are denoted by the same reference numerals, and their explanations will be omitted. In Fig. 3, the light from the image carrying object is transmitted through the lens 2.
1 and enters the mirror 22 , where the optical path is changed by total reflection, and then passes through the lens 23 and enters the movable mirror 24 .

The movable mirror 24 constitutes the optical scanning means 14 together with a timing generating circuit 25, a scab driver 26, and a scab 27, which will be described later. It rotates back and forth inside. As a result, optically scanned light is extracted from the movable mirror 24, passes through the lens 28, and enters the solid-state lliii imager 13 (IRCCD).

The solid carrier element F13 is placed in the container of the detector 29,
It is frozen by a refrigerator 30. This solid-state image sensor F1
The video signal taken out from the final stage source follower FET (corresponding to 54 in Figure 5) is input to the A/D converter 32 through amplifier 31 (corresponding to amplifier 56 in Figure 5), where it is converted into a digital signal. After being converted, it is supplied to the signal processing/display circuit 33.

The signal processing/display circuit 33 performs offset correction and sensitivity correction on the input digital video signal through digital signal processing, and then performs scan conversion and sends the corrected data to the D/A converter 34 in an order that can be displayed on a TV. Output. D/A converter 3
4 converts this data into an analog signal again, and inputs the analog signal to a display device 35 using a cathode ray tube (CRT), where an infrared image is displayed.

On the other hand, the timing signal generating circuit 25 drives the solid-state decoy image element 13 and the scanner 27. Generates timing pulses for correction and display. The scanner driver 26 receives this timing pulse and generates a voltage waveform for tricking the Fv block 27.

Further, the driver/bias power supply 36 includes the MmJ means 15, which generates a drive pulse for charge transfer and a bias voltage, respectively, based on the above-mentioned timing pulse, and supplies them to the solid-state image sensor 13.

The block configuration of the infrared carrier image device of this embodiment is basically the same as that of the conventional infrared image device, except that the driver and
Bias power supply 36 between effective scanning II and blanking I]
The timing generating circuit 25 is configured to have a function of varying the output between the two, and the timing generating circuit 25 can generate a control signal 4t to cause the driver bias power supply 36 to perform such a movement. is different from conventional infrared decoy imaging.

FIG. 4 shows a block diagram of one embodiment of the driver bias power supply 36 of FIG. The data selectors 41 and 42 each receive input signals from the timing pulse generation circuit 25.
- when the effective scanning bright interval is "a", the terminal (
A) selects and outputs the φ1 and φ4 data input to φ1 and the Vo generation data, respectively, and outputs the blank Englillr+. T
At the time of 2, the data input to the input f(B) is selectively output.

The output data of the data selector 41 is taken out through the driver 43, and is used as four-phase initial pulses φ1 to φ4 during the effective scanning period Ta, and during the blanking period T.
＋． During T2, it is input to the fixed-rest withdrawal a-element 13 as a fixed level bow.

On the other hand, the output data of the data selector 42 (is converted into digital and 7-log by the D/A converter 44, and is output as the drain voltage vO of the FET of the source follower at the final stage during the effective scanning period Ta; on the other hand, During the blanking periods T+ and Tz, it is output as Ov.

In this way, in this embodiment, the fixed-rest dynamic image element 13 is operated by the movable mirror 24 and the scanner 27 for effective scanning t! The same dance @ movement as before is performed only between 11 and a, and blanking J
flfFIIT+. That ili in T2! By stopping the operation, power consumption can be reduced to approximately 60 to 70%. Therefore, solid ffi image #F1
Since the heat loss of 3 is reduced in accordance with the reduction in power consumption, it is possible to use a small and inexpensive refrigeration EL30 that does not require as much refrigeration capacity as the conventional refrigeration EL30.

〔Effect of the invention〕

As described above, according to the present invention, the power consumption of the solid-state image sensor can be reduced, so the cooling means for the solid-state image sensor can be made smaller and cheaper, and the same cold FD means as the conventional one can be used. When used, the cold FA temperature of the solid-state decoy image element can be lowered, so it has the advantage of improving the performance of neck mounting.

[Brief explanation of drawings]

Fig. 1 is an original configuration diagram of the present invention, Fig. 2 is an explanatory diagram of the function and operation of the present invention, Fig. 3 is a configuration diagram of an embodiment of the present invention, and Fig. 4 is a diagram of an embodiment of the present invention. A block diagram of the main parts, Fig. 5 is a composition diagram of an example of the conventional main part, Fig. 6 is an explanatory diagram of the power consumption generating parts inside the detector, and Fig. 7 shows the optical scanning and frame time of the conventional device. It is a drive pulse explanatory diagram. In the figure, 11 is an infrared light receiving element, 12 is a charge transfer element, 13 is a solid-state image sensor, 14 is an optical scanning means, 15 is a control means, 25 is a timing generator circuit, and 36 is a driver bias power supply. .

Claims (1)

[Scope of Claims] A system that stores and transfers signal charges obtained by photoelectric conversion by a plurality of infrared light receiving elements (11) arranged in one direction using a charge transfer element (12). In an infrared imaging device in which a solid-state imaging device (13) having a self-scanning function in a direction is optically scanned in a direction perpendicular to the one direction by an optical scanning means (14) and light from an imaging target is incident on the solid-state imaging device (13). Charge transfer driving pulses and bias voltage are applied to the solid-state image sensor (13) only during the effective scanning period of the optical scanning period of the optical scanning means (14), and the driving pulses are applied during the blanking period, which is the remaining scanning period. and a control means (15) for stopping the supply of bias voltage and maintaining it at a constant voltage.