JPS60119179A - Infrared-ray image pickup device - Google Patents

Abstract

PURPOSE:To display with high performance under a wide temperature condition by providing the titled device with a device storing and generating a signal corresponding to disturbance light due to a temperature in a specific device and a detector detecting the temperature in the device and subtracting a disturbance light component included in an output from an infrared-ray detector by using said devices. CONSTITUTION:When the temperature of a part generating disturbance light 7 is T1 deg., an output NT1 from a corrected storage generating circuit 10 for generating a signal NT1 corresponding to the disturbance light 7 is applied to a multiplier 13. The circuit 10 is constituted by a storage device, e.g. a programmable read-only memory (PROM), the stored contents are programed by measuring the characteristics of the device and the reading timing 15 is read out synchronously with the output of a signal processing circuit 4. A subtractor 14 subtracts the output of the multiplier 13 from the output of the circuit 4, so that a high performance infrared-ray image pickup device completely preventing a video output from influence due to the disturbance light 7 can be provided.

Description

[Detailed description of the invention] [Technical field of invention] This invention relates to improvements in infrared imaging devices.

[Prior art]

Figure 1 shows a conventional infrared imaging device. In Figure 2, the infrared rays emitted from the subject enter the imaging optical system (2) as incident light (1), and the output becomes signal light (5), which is infrared rays. The signal is detected by a detector (3) and converted by a signal processing circuit (4) into a video signal for display on a monitor television or the like. On the other hand, the infrared rays detected by this device are generally emitted from all kinds of objects.1 For example, as shown in the figure, the infrared rays emitted from the storage case (6) of the imaging optical system (2), etc. ), which has the disadvantage of deteriorating the performance of infrared imaging devices.

Incidentally, the above disturbance light (7) is infrared light that cannot be cut off into binary light even if nine various measures are taken and is incident on the infrared detector (3), and also due to the ambient temperature and Since it changes due to the heat generated by the imaging device itself, it is one of the causes of a significant deterioration in the performance of the device.

[Summary of the invention]

The present invention has been made with the aim of improving such drawbacks, and focuses on the fact that the amount of the ambient light (7) changes depending on the temperature inside the device. Equipped with a device that stores and generates the corresponding signal and a detector that detects the temperature inside the device.

By subtracting the disturbance light component contained in the output of the infrared detector based on these, an infrared imaging device that exhibits good performance under a wide range of temperature conditions is provided.

[Embodiments of the invention]

FIG. 2 shows an embodiment of the present invention.
7) is exactly the same as the conventional device shown in FIG. Here, to first explain the nature of the disturbance light (power), the output of the infrared detector (3) due to the disturbance light (power), NT, when the disturbance level is generally ゛T, is expressed by the following equation.

NT-σ・T- is 1・K2・K3... (1) where σ is Sten-Ann-Boltzmann constant 'Y: Absolute temperature at the position where the disturbance source is radiated 1: Infrared emissivity at the position where the disturbance light is radiated 2: Ratio of light received by the infrared detector (3) in (σ・T−1) Kl Detection efficiency of the infrared detector (3) In equation (1), the environment in which a certain imaging device is used, etc. The items that change are T and 6. Therefore, the above (1
Equation 1 can be simplified and expressed as the image of the following equation.

NT = KO-TN - (21 However, KO = σ・K1・K2... (3) TN:
T −K3 ... (4) Furthermore, TN is the temperature, and once T is known, it can be easily calculated by measuring the characteristics of the manufactured device. Therefore, in the present invention, disturbance light (7) f is generated. When the temperature of the part is 71 degrees (for example, 293 degrees or 20 degrees Celsius), the disturbance light (
7), the disturbance equivalent signal appearing in the output of the infrared detector (3): NTl Correction memory generation circuit O1 for generating all NTl
Set up that crab TN1'! Add to the i7 multiplier circuit. This correction signal storage generation circuit a1 has a storage device such as p
ROM (Programmable+) - consists of a 7-way memory, the stored contents are programmed by measuring the characteristics of the device, and the successive output timing α is determined by the signal processing circuit (4
) can be read out in synchronization with the output.

10,000Ql) is a temperature detector for detecting the temperature T2 of the part that generates disturbance light (force), and its output is also given to the correction constant generation circuit 3.However, this correction constant generation circuit a is TNl. : Value TN2° equivalent to equation (4) for Ti
It consists of a memory device that measures and programs the specific characteristics of the device so as to generate a constant 4, which is the value equivalent to equation (4) at T2, and 4 is a multiplier circuit for the output. given to.

Therefore, the output NTM of the multiplication circuit 03 is expressed by the following equation.

In other words, Equation 6) calculates the output of the infrared detector (3) due to the disturbance light (7) explained in Equation (1), and the subtraction circuit aa calculates 1 from the output of the signal processing circuit (4). By subtracting the output of the multiplier circuit Q3, a high-performance infrared imaging device can be provided in which the video output is completely unaffected by the disturbance light (7).

As mentioned above, since the contents of the correction signal generation circuit aI and the correction memory generation circuit yen are fluctuated according to the specific measurement results of the device, all the disturbance light generated internally in addition to the disturbance light caused by the temperature 2, for example, Narcissus. It is a matter of fact that the present invention can also eliminate such problems.

〔Effect of the invention〕

As explained above, according to the present invention, by providing the units 01 to a shown in FIG. f
This has the effect of being able to provide M imaging devices.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional infrared gland imaging device;
FIG. 2 is a block diagram showing one embodiment of the present invention. In the figure, (3) is an infrared detector, (4) is a signal processing circuit, (7) is disturbance light, Ql is a correction signal storage generation circuit,
(1υ is a temperature detector, 02 is a correction constant generation circuit, a rise is a multiplication circuit, (141 is a subtraction circuit. The same line number in Figure 1 indicates the same case or a corresponding part. Agent Masuo Oiwa

Claims (1)

[Claims] a correction signal storage generation circuit that stores an incorrect signal included in the output of the infrared detector in a certain specific state; a temperature detector that detects the temperature within the infrared imaging device; An infrared imaging device comprising a correction constant generation circuit that corrects the output of the correction signal storage generation circuit.