JPH0387620A - Infrared ray image pickup device - Google Patents

Abstract

PURPOSE:To facilitate the adjustment of an offset level by adding offset level display data to image data so that the offset level is displayed simultaneously with an infrared image on a screen. CONSTITUTION:Incident infrared rays are converted to an electric signal within a prescribed range by a converting means M1, and converted to two-dimensional image data by an image data generating means M2. Subsequently, an offset level (a level of an electric signal) at the time of converting in the converting means M1, and at that time, a data adding means M4 adds data for displaying an offset level to the image data. Therefore, when this image data is sent to a display device, the offset level comes to be displayed simultaneously with an infrared image on a screen, and the offset adjustment can be executed easily.

Description

[Detailed Description of the Invention] The present invention provides an infrared ray that can display the two-dimensional temperature distribution of an object to be measured on a screen or record it as image data by photographing the object to be measured. It relates to an imaging device.

All objects emit infrared radiation according to their temperature, unless the temperature is absolute zero. Focusing on this, technology has been known for a long time to measure the temperature of an object by measuring the amount of infrared radiation emitted by the object. Furthermore, infrared imaging devices that two-dimensionally photograph this and capture it as an image are already widely used.

This infrared image represents a certain temperature range on the screen, but at that time, it is important to know which temperature range to display (usually the lowest temperature level) and the width of that temperature range (from what temperature to what temperature). ) must be specified. Hereinafter, the former will be referred to as an offset level, and the latter will be referred to as a window.

Conventionally, the offset level was adjusted to obtain an appropriate temperature distribution image while looking at the infrared image appearing on the screen, but the infrared image itself It is difficult to adjust the infrared image to a constant level because the low temperature and low temperature areas are intermingled.Especially when trying to make the gradation of the infrared image the same between the previous observation and the current i-measurement, or When it is desired to display the object to be measured on the same scale, it is difficult to adjust the offset level to a constant level just by looking at the infrared image.

Another inconvenience when adjusting the offset level is that if the gain used to convert the infrared intensity to image shading changes, the offset level may move too quickly or move too slowly when adjusting the offset level. This means that it takes time.

An object of the present invention is to solve such problems and provide an infrared imaging device whose offset level can be easily adjusted.

In order to achieve the above-mentioned objective, the infrared imaging device of the present invention scans the object to be measured two-dimensionally to receive infrared rays, and displays the intensity of the infrared rays as gradations on the screen. In an infrared imaging device that converts infrared image data into image data, the offset level is defined as an infrared intensity to be converted to a predetermined reference density when converting infrared rays into image data; The present invention is characterized by comprising means for adding offset level display data to the image data so that it is displayed simultaneously with the image.

At this time, the apparatus may further include means for changing the gain during conversion from infrared rays to image data, and means for changing the speed of changing the offset level in accordance with the gain.

Alternatively, the device may include a key switch that outputs a signal corresponding to the amount of depression, and means for changing the speed at which the offset level is changed in accordance with the output signal from the key switch.

In the Chi-Satomoto infrared imaging device, as shown in FIGS. 1(a) to 1(c), incident infrared rays are converted into electrical signals within a predetermined range between conversion means, and image data are converted into electrical signals within a predetermined range. is converted into two-dimensional image data. In the first aspect of the present invention, as shown in FIG. 1(a), between the offset level changing means, the offset level (
At that time, the data adding means adds data indicating the offset level to the image data. Therefore, when this image data is sent to a display device (not shown), the offset level will be displayed on the screen at the same time as the infrared image. Adjustments can be made easily.

In the second aspect, as shown in FIG. 1(b), a means M5 for changing the gain during conversion from infrared rays to an electric signal is provided, and between the changing speed changing means, the magnitude of this gain is Accordingly, the offset changing speed of the offset level changing means M3 is changed.

In the third aspect, the offset changing speed changing means is changed not according to the gain, but by the key switch M7 by the operator.
The offset changing speed of the offset level changing means h3 is changed according to the amount of depression of the offset level changing means h3.

In these cases, the speed of change in offset level is
Since it changes smoothly or arbitrarily depending on the sense of the viewer, offset adjustment becomes easy.

Sharp treatment group Embodiments of the present invention will be described below with reference to the drawings.

<Appearance> As shown in FIG. 2, this embodiment is a portable infrared imaging device 10, and as shown in FIG. 5, it can be carried on the shoulder and operated by holding the grip 12 with both hands. It is possible to observe an infrared image of an object. Main body 1 of device 10
4 has a movable grip 12 that protrudes on both sides at the lower front.
In addition, there is a battery back 16 as a power source and a CRT Pure 18 that allows you to observe infrared images etc. on the spot.
is installed. Plan view of Figure 3 (a), (b)
As shown in the front view, the grip 12 has a shape that is easy to grasp with the left and right hands, and various switches are arranged within the reach of the fingers of each hand holding the grip 12.

Details of these switches will be described later. Further, a side panel as shown in FIG. 4 is provided on the side surface (the opposite side in FIG. 2) of the main body 14, and various switches in addition to the power switch 20 of the device 10 are arranged thereon. As will be described later, only the switches that are operated first after the power is turned on are arranged on this side panel, and during normal observation, only the switches provided on the grip 12 are operated. It is designed so that you can Therefore, the operator can perform focusing, offset of the infrared image screen, and window adjustment, which will be described later, while holding the grip 12 and looking into the pure 18.

Imaging Principle> The imaging principle of the present device 10 will be explained using FIG. 6. Infrared light 4!22 emitted from the object is reflected by one surface of the polygon mirror 24, passes through the condenser lens 26, and is then detected by the infrared detector 28. At this time, by rotating the polygon mirror 24, the surface to be photographed 30 can be horizontally scanned. Furthermore, a plurality of infrared detection elements are arranged in the detector 28, and when one surface (first surface, second surface, ...) of the polygon mirror 24 is rotated by a predetermined angle, a range having a certain width ( band) is scanned - degrees. Then, the mirrors around the polygon mirror 24 are tilted at a constant angle with respect to the rotation axis 2, and the scanning bands of each surface (band l, band 2, . . . , band n0, here n=6) By arranging it so that it covers the top without any gaps, one rotation of the polygon mirror 24
Screen images can be taken.

The infrared detector 28 generates an electrical signal according to the intensity of the detected infrared rays, and this electrical signal is processed by the control circuit shown in FIG.
In Figure (a), it is displayed as a gray scale image on a display device 49) or output as a video signal.

<Image Data Generation> The signal output from the detector 28 in FIG. As described later, the offset injection circuit 33 arbitrarily changes the reference level (offset level) of the signal from the low-pass filter 32 by injecting the signal from the D/A converter 34 into the signal from the low-pass filter 32. It is something that makes you

The output signal from the offset injection circuit 33 is input to a multiplexer 35, where a number of signals corresponding to the number of detection elements of the multi-element infrared detector 28 are multiplexed. The multiplexed signal is amplified by an amplifier 36, digitized by an A/D converter 37, and guided to an image memory (RAM) 38.

On the other hand, the polygon mirror 24 is rotated by a motor 25, and its rotation is monitored by a photosensor 40, and a timing generation circuit 41 generates a timing pulse based on the detection signal. This timing pulse is counted by a manual address counter 42 and outputted to the image memory 38 as an address signal corresponding to the rotation angle of the polygon mirror 24.

The image memory 38 stores the infrared intensity value from the A/D converter 37 at the address indicated by the input address counter 42. In this way, image data for one screen corresponding to one rotation of the polygon mirror 24 is stored in the image memory for three days.

Image Data Reading> The image data stored in the image memory 38 is displayed on a Pure 18 CRT using a normal TV. Therefore, first, the television synchronization signal generator 44 generates a synchronization signal, and the output address counter 45 generates address data for the image memory 38 based on the synchronization signal. Data within the address specified by this address data (infrared intensity data) is input to the γ-PROM 46. γ-FRO
M46 is for converting the detected infrared intensity value to the brightness value on the CRT screen. Compensates for nonlinearities such as the relationship between the amount of light that enters the human eye and the intensity of light that humans perceive (
γ correction) to provide linearity between the temperature of the object to be measured and human sensation.

The output of the r-FROM 46 which has been γ-corrected in this way is D/
The A converter 47 converts the signal into an analog quantity, and outputs the signal to the pure 18 display device (CRT) 49 via the synthesis circuit 48 or to the outside from the terminal 50.

Since the output of this synthesis circuit 48 is in a composite video signal format, it can be used with various external devices. You can also record on a VTR. Note that the synthesis circuit 48 also inputs various character information (described later) generated by the character generation circuit 51.
Incorporate them into the video signal so that they can be displayed on the screen.

<Switches> The infrared image is displayed on a CRT etc. as described above, but
All operations of this device 10, including such processing, are performed by the CPU.
52. Before explaining this control, the functions of the various switches (see FIGS. 4 and 3) of the device 10 will be briefly explained below.

-Mode (MOCE) key 53: Switches the screen display between the initial screen (described later) and the infrared image adjustment screen.

- Function selection (SELECT) key 54: Selects which set value is to be made changeable.

-Up/down key 552 Changes the selected setting value.

・VTR key 56: When using a VTR, (-(7) VTR (
7) Start and stop.

・O/W key 57 Cyclically switches between the three secondary modes.

(a) Auto offset adjustment (b) Manual offset adjustment (C) Manual offset - window adjustment +/-
The keys 58 are in the shape of a zigzag saw, and by pressing the + side or - side, the offset is raised or lowered or the window is changed. When you release your finger, it returns to the neutral position.

-F/M key 59: Cyclically switches between the following three modes.

(a) Real-time temperature measurement (b) Infrared image screen freeze (c) Storing temperature value in memory and unfreezing ・W/B key 60: Select whether to make the high temperature area white or black on the screen do.

- Focus (F/N) key 61: Performs focusing.

In the device W10 of this embodiment, the key switches are connected as shown in FIG. 8, and the operation of any of the key switches is detected by the CPU 52. In addition, in FIG. 7(a), various key switches connected to the CPU 52 are collectively represented as 62.

<Summary of various functions of the device> Next, various functions of the infrared imaging device 10 related to the observation of the above-mentioned infrared image will be described.

- When the focus key 61 on the right side of the focusing grip 12 is pressed on the F (far) or N (a) side, the CPU 52 detects this and sends a forward or reverse motor drive command signal to the focus lens drive circuit 63. Output. Thereby, the lens drive circuit 63 rotates the lens drive motor 64 forward or backward, and moves the infrared condensing lens 26.

・Offset Adjustment Offset adjustment is used to raise or lower the level of the entire temperature range displayed on the screen. By pressing the O/W key 57, the CPU 52 alternately switches between an auto offset adjustment mode and a manual offset adjustment mode (including a mode in which the window can be further adjusted).

Figure 7 (b) shows a circuit related to offset adjustment.
) and FIG. 7(c) showing an example of a specific configuration of the offset injection circuit 33, the offset adjustment of this embodiment will be explained.

The polygon mirror 24 is equipped with a chopper (not shown), and during the period when the polygon m24 is not scanning the object to be measured, the detection! S28 is covered to prevent infrared rays from an object from entering the detector 28. Then, when entering this period, the timing generation circuit 41 outputs a pulse signal (referred to as a clamp pulse, sl on the lower side of FIG. 14). The output signal s2 from the low-pass filter 32 is as shown in the upper part of FIG.
A signal s corresponding to the energy radiated from the chopper itself
3 (However, as shown at 34 in FIG. 14, if the temperature of the object to be measured is lower than the chopper temperature, there may be an output lower than the signal s3.#). Therefore, by clamping this signal s3 with an arbitrary offset voltage at the time of the clamp pulse, as shown in FIG. It can be changed to . In FIG. 15, V A/Dmax
and VA/Dmin indicate the maximum level and minimum level that the A/D converter 37 can convert from analog to digital, respectively, and finally the signals within this range are displayed in black and white on the screen. Represented by shading. Therefore, if it is desired to observe the part s5 where the infrared intensity is stronger (the part where the temperature is higher), the offset level may be set lower as shown on the left side of FIG. 15. Also, if the offset voltage is set too high as shown on the right side of Figure 15, V A/Dma
The portion beyond this will turn white (or black, depending on the setting of the W/B key 60).

(auto offset), iJl adjustment mode, CPU5
2 sends an auto selection signal to the auto/manual switching circuit 66. Thereby, the signal output from the comparison circuit 67 can pass through the auto/manual switching circuit 66,
It is input to the counter 68. The comparison circuit 67 is connected to the amplifier 3
When the average level of the signal output from 6 is higher than a predetermined value Va, a down command signal is issued, and a predetermined value V lower than that is issued.
When the voltage is lower than Vb (ie, Vb<Va), an up command signal is output. On the other hand, clock pulses from the CPU 52 are input to the counter 68, and the counter 68 determines the number of clock pulses from the comparison circuit 67.
The count value is increased or decreased in accordance with an up or down signal command from the D/A converter 34. This results in
The amount of offset injection in the offset injection circuit 33 increases or decreases, and the output level of the amplifier 36 returns to between Va and vb.

Such feedback control automatically adjusts the offset. Note that the offset injection circuit 33 may be configured, for example, as a circuit as shown in FIG. 7(c) for each detection element of the infrared detector 28. Furthermore, the magnitudes of the reference voltages Va and vb of the comparison circuit 67 are determined by circuit constants.

In the case of manual offset circumference adjustment, the CPU 52 sends a manual selection signal to the auto/manual switching circuit 66 and invalidates the signal from the comparison circuit 67.

After doing so, the CPU 52 controls the clock pulse sent to the counter 68 by itself in accordance with the operation of the +/- key 58, and increases/decreases the output of the D/A converter 34 to change the offset.

Note that the speed of change of this offset can be made variable depending on the gain of the amplifier 36, but this will be described in detail later.

Here, FIG. 7(d) shows an embodiment of the comparison circuit 67, auto/manual switching circuit 66, and counter 68. Analog switch SWI is timing generation circuit 41
The polygon mirror 24 is controlled to be ON only during the period when the effective field of view is being scanned by the field of view signal output from the polygon mirror 24. The output signal of the amplifier 36 is input to the comparator circuit 67 while the analog switch SWI is ON, and is averaged by the resistor R and capacitor C. This average voltage is the comparator CPI
It is input to the non-inverting input terminal of CP2 and the inverting input terminal - of comparator CP2. On the other hand, the reference voltage Va is input to the inverting input terminal - of the comparator CPI, and the reference voltage vb is input to the non-inverting input terminal of the comparator CP2. With this configuration, the average voltage is reduced to Va
When the average voltage is larger than vb, a signal of "1" is output from the comparator CPl, and when the average voltage is smaller than vb,
A signal of "1" is output from the comparator CP2. These signals are then sent to the auto/manual switching circuit 6.
6 is input.

In addition to the auto/manual switching circuit 66, CP
Punishment/MANUAL signal output from U52 and UP
/DOW)J signal is input. In auto offset adjustment mode, this AUTO/MANUAL signal is
0'' (auto selection), the analog switch SW2 is turned on, and the analog switch SW3 is turned off.

Therefore, the signal output from the comparator CP2 is input to the UP/DOWN terminal of the counter 68.

When the average voltage is larger than Va or smaller than vb, the output of the OR circuit ORI becomes "l", and this signal is input to the enable (ENAOLE) terminal of the counter 68. Then, the counter 68 counts clock pulses from the CPU 52. At this time, when the output of the comparator CP2 is "1", that is, when the average voltage is smaller than vb, the count-up mode is entered, and by counting the clock pulses from the CPU 52, the output of the D/A converter 34 is growing. Then,
The offset voltage increases, and the output of the amplifier 36 increases. When the output of the amplifier 36 becomes a value between Va and vb, the input signal of the enable terminal of the counter 68 becomes "0".
, the count stops, and the offset voltage stops changing. Further, when the output of the comparator CP2 is "O", that is, the output of the comparator CPI is "1", and the average voltage is larger than Va. At this time, the counter 68 enters the countdown mode, and the output of the D/A converter 34 decreases due to the clock pulse from the CPU 52, and stops when the average voltage falls between Va and vb, as described above. In this way, the amount of offset is automatically adjusted, and the average voltage of the output of the amplifier 36 is
The value is kept between 0 and 0.

Next, in manual offset adjustment mode, draw/
The MANtlAL signal is “1J (manual selection signal)
Therefore, the output signal of the OR circuit ORI becomes "1", and this signal is input to the enable terminal of the counter 68. In other words, in the manual offset adjustment mode, a signal of "1" is always input to the enable terminal. Also, at this time, analog switch SW2 is OFF.
Therefore, analog switch song 3 is turned ON. Therefore,
UP/DOWN of counter 68 5i child Niha CPU52
A (7) UP/DOWN signal is input, and the counter 68 counts up or down based on this signal. Then, an offset amount is injected according to the count value. Note that the UP/DO signal and clock pulse are output in response to the operation of the +/- key 58, and are counted only while the +/- key 58 is operated. There is.

・Window adjustment Window adjustment changes the width of the temperature range displayed on the screen. This window adjustment can be done by changing the gain of the circuit or by changing the range filter 70 in front of the detector 28 to change the transmittance of infrared rays. To change the circuit gain, the CPU 52 uses the amplifier 36.
This is done by changing the gain of Furthermore, switching of the range filter 70 is performed by the CPU 52 rotating the motor 72 using the filter drive circuit 71.

- The signal from the temperature calculation detector 28 is inputted to the sample hold circuit 75 at the stage when it is output from the preamplifier 31, and then sent to the CPU.
It is sampled by a sampling signal from 52. The sampled and held signal is sent to multiplexer 76.
The signal is multiplexed by the A/D converter 77, digitized by the A/D converter 77, and input to the CPU 52.

At this time, a signal from the detector 28 regarding its sensitivity (this changes depending on the temperature of the white of the detector 28) and a signal from the temperature sensing element 78 provided inside the device 10 are also input to the multiplexer 76. , multiplexer 76
multiplexes these three signals and outputs it to the CPU 52. The latter two signals are for correcting the former signal.

The CPU 52 calculates the temperature of the object to be measured based on these three data. To calculate the above temperature, use F/M key 59.
Executes when is pressed.

In addition to the functions described above, by sending a character signal to the character generation circuit 51, it also has a function of displaying character information such as the above-mentioned calculated temperature value of the object to be measured and the current time on the CRT screen. The current time is obtained by accessing the clock IC 80.

In addition to the programs that execute the functions explained above, C
All operating programs for the PU52 are stored in the ROMB2. Further connected to the CPU 52 are a RAM 82 that temporarily stores data and an EtPROM 83 that can store data even when the power is turned off. E”P
l? 0M83 stores calibration information and the like used when the CPU 52 calculates the temperature.

<Operation of CPU> Next, the operation of the CPU 52 will be explained with reference to the flowcharts of FIGS. 9(a) to 9(i).

First, when the power of this device 0 is turned on, step 11
Then, initialize the internal registers of the CPU 52 and the RAM 82,
Calibration information stored in E”FROM83 is transferred to RAM8.
Perform initialization processing such as importing into 2. Next, in step 12, an initial screen as shown in FIG. 11 is displayed.

Here, the contents of the initial screen will be explained with reference to FIG. 11(a). In the upper area, information regarding the additional lens to be attached to the device IO is displayed. The next stage area■
displays the unit of temperature that will be displayed from then on. The current date and time are displayed in the bottom area (■).

On this initial screen, you can set the date and time and select the temperature unit. In step I3, by flashing specific characters on the initial screen,
It shows which items (setting values) can be changed by the up/down keys 55.

For example, in FIG. 11(a), the item value (rrN
TERNALONLYJ (that is, internal lens only) is blinking, but by pressing the up/down key 55, the item value changes to "rWIDE" (wide-angle lens, etc.).

In step I4, it is checked whether the mode key 53 has been pressed. If not pressed, the function selection key 54 or up/down key 55 is pressed in step 119.
Checks whether or not is pressed.

If these keys are not pressed either, the process returns to step 2. If it is determined in step l19 that either the function selection key 54 or the up/down key 55 has been pressed, the setting of the initial display screen is changed in accordance with the pressed key in step 110, and step W], 1
Change the displayed characters and return to step #2. For example, if you press the function selection key 54 while the item value of the lens used item (rLENsIN USEJ) is blinking, the next item, temperature unit ('tlNIT ”) item value “C
' will start flashing. Furthermore, by pressing the function selection key 54 several times, the "seconds" part of the current time display will start blinking. In this state, by pressing the up/down key 55, the seconds display will change from "30" to "31'' (Fig. 11(C)).

If the mode key 53 is pressed in step I4, the screen is switched to a screen for adjusting the infrared image in step II5. In other words, the screen shown in FIG. 11 is switched to the screen shown in FIG. 12.

Here, we will explain the infrared image adjustment screen. In the center of the screen, there is a large area @ for displaying the infrared image, and on the left and right and below, additional information such as setting conditions regarding the infrared image is provided. is displayed. The display areas of each additional information will be explained below.

Information regarding the focus is displayed in the top area (■) of the right column. Specifically, focus key 6
When the F or N side of 1 is pressed, "F↑" or "F↓" is displayed.

Information regarding the window is displayed in the next row, area ■. Specifically, as the range filter 70 changes, either "H"/"M"/"L" is displayed, and as the circuit gain changes, the displayed value changes between "(" and "7"). It changes with

Offset information is displayed in area ■. When in auto offset adjustment mode, rOFA is displayed, and when in manual offset adjustment mode, "OFM" is displayed.

Furthermore, in manual offset adjustment mode, press +/- key 5.
When the offset is changed by 8, roF
"M↑" or "○FM↓" is displayed.

The current setting value of emissivity is displayed in area ■.

rLIsT is displayed in area ■, and by pressing the function selection key 54, select ``rLIsT'' and pressing the up/down key 55, the data is stored in the memory as shown in FIG. 12(b). Data such as temperature values are displayed on the screen. To briefly explain the list in Figure 12(b), the numbers in the leftmost column (1 to 10) indicate the record numbers in memory, with 1 being the newest and 10 being the oldest in the 0th column. The letters represent the temperature measurement mode, r3. is the instantaneous value,
rAV IJ, "AV2" indicates the average value, and rPKJ indicates the peak value.

The next "EJ" column is the emissivity, and the "TJ" column is the temperature measurement value.

Returning to FIG. 12(a), the above-mentioned temperature measurement mode and temperature calculation value are displayed in area (3).

On the left side of the area [phase] below the infrared image display area (■), an indication "vl" indicating that recording is in progress is displayed, and on the right side, the date and time are displayed as in the initial screen.

A gray scale is displayed in MAo at the left end.

The thin column (■) on the right side is an offset indicator that displays the offset level.

The display of this offset indicator will now be described in detail. In addition to a data area for displaying an infrared image, the image memory 38 is provided with screen data areas for displaying this offset indicator, the number of which is equal to the number of scanning lines on the TV screen.

During the period corresponding to the display of this area (tl in FIG. 13(a)), the output address counter 45 sends the address of the screen data area corresponding to this display area @ to the image memory 38, and displays the infrared image display area @ The period corresponding to (Figure 13 (
At t2) in a), the address of the area where the infrared intensity has been written as described above is sent to the image memory 38.

As mentioned above, when the offset injection amount changes due to automatic or manual offset adjustment, the CPU 52
is the output count value of the counter 68, and its offset level can be known. If the D/A converter 34 is for 10 bits, the count value of the counter 68 is 0.
-1023. On the other hand, in the case of the NTSC system, the number of effective scanning lines on the TV screen is 484 in -S;
It is assumed that the offset indicator is represented by 400 lines in consideration of overscan. As shown in FIG. 13(a), if the offset indicator ■ is represented by lines 40 to 439, the relationship between the output count value DOF of the counter 68 and the corresponding TV line number LN is LN--399X (DOF -1023) /1023
+40...(1). This TV line number L
The current offset value is displayed on the offset indicator in an easy-to-understand manner by calculating the address of the above memory area of the image memory according to N and writing data that becomes a mark in the area to be set at the offset level. For example, as shown in FIG. 13(b), the image memo IJ3
'l is in the memory area corresponding to DOF=O~^D1 of 8.
100OOB J (B represents a binary number), AD1
+l~AD2 has rolooooB'', AD2+1~
If data such as "r 110000B" is written in 1023, the offset indicator (■) on the screen will display gray-0-gray in order from the bottom.

Returning to the flowchart of FIG. 9(a), step l15
After switching to the infrared image adjustment screen, in step #6, the display of the item value of one item on the screen blinks to indicate that the setting of that item can be changed. For example, in FIG. 12(c), the roFMJ display is blinking, indicating that the offset level can now be changed manually. In Fig. 12(d), “H
6" is flashing, indicating that the window (range filter or gain) is currently adjustable. Next, scan all the key switches in step #7,
Check if any key is pressed.

If no key is pressed, the process returns to step #5. If any key is pressed, the type of key switch is determined in step #8, and only if it is the mode key 53, the process returns to step #2 to change the display to the initial screen, and if it is any other key switch. If so, processing corresponding to each key switch is performed in step #12. Below, the processing when each key switch is pressed will be explained with reference to FIGS. 9(b) to 9(i).

- F/M key When the pressed key is the 17M key 59, the routine shown in FIG. 9(b) is executed. In this routine, in steps 120 and #22, the flag F in the RAM 82 is
Check whether the value of IIZ is 0 or 2 (if neither, FRZ=1). This flag F
RZ stores the current temperature measurement mode state, and its value corresponds to each of the following modes.

FRZ・0: Screen freeze release mode. Storage of temperature values in memory also takes place.

FRZ・1: Screen freeze mode, fixes the infrared image at a certain moment.

FRZ・2: Real-time temperature measurement mode. A moment-by-moment infrared image is displayed on the screen.

When it is determined in step 1120 that the FRZ is 0,
Only by changing the flag FRZO value to 2 in step 121, the process returns to step I5 in FIG. 9(a).

When it is FRZ.2, the value is changed to 1 in step 123, and the screen display at that moment is fixed in step 124.

This is the image memory 3 of the output data of the infrared detector 28.
This is done by prohibiting writing to the image memory 38 and permitting only reading from the image memory 38.

In step 122, FRZ is not 2 (i.e., FRZ
- 1) If so, FRZ is set to 0 in step 125, and in step 1126, writing to the image memory 38 is permitted and the screen is released from the frozen state. Then, in step 127, it is checked whether the 17M key 59 has been pressed for more than a predetermined time (for example, 2 seconds), and if it has been pressed for more than a predetermined time, then in step #28, the temperature value etc. calculated by the interrupt routine, which will be described later, etc. is stored in the RAM 82. The data stored here is shown in Figure 12 (a) as explained earlier.
) and (b). Next, in step 129, the temperature display value calculated in the interrupt processing routine and displayed on the screen is cleared (erased). If it is determined in step s27 that the 17M key 59 has not been pressed for a predetermined period of time or more, the temperature display value is cleared in step #29, and the process returns to step I5.

- W/B key When the pressed key is the W/B key 60, the most significant bit of the address data input to the r-PROM 46 is inverted in step 130 of FIG. 9(c). TPR
The OM46 stores two types of conversion tables: one in which high temperature is white and low temperature is black, and the other in which high temperature is black and low temperature is white.The value (0 or l) of the topmost via) can be changed. By doing this, you can switch the table to be used.

After that, return to step #5.

-Focus Key If the pressed key is the focus (F/N) key 61, the routine shown in FIG. 9(d) is executed. Here, in step 1131, a focus signal corresponding to the F side or N side is sent from the CPU US2 to the focus lens drive circuit 63, and the condenser lens 26 is moved by the motor 64.

In step #32, a signal is sent to the character generation circuit 51 to indicate that this key switch is pressed.
Display the characters "F↑" or "F↓" in area ■ on the screen. Then, in step 1133, a check is made to see if this key continues to be pressed, and if it is, the process returns to step 131 to continue sending the focus signal. When the focus key 61 is no longer pressed, step 13
Proceed to Step 4 to stop outputting the focus signal, clear the character display in area (■), and return to Step 15.

- VTR key If the pressed key is the VTR key 56, the routine proceeds to the routine shown in FIG. 9(e), and in step #35 a VTR start or stop signal is output to the connector terminal 79 connected to the VTR machine. do. Then, in step 136, if recording is in progress, a display "Vl" to that effect is displayed in the lower area [phase] of the screen, and the process returns to step #5.

・○/W key If the pressed key is the O/W key 57, the routine proceeds to step 1137 in FIG. Check to see if it continues. If it is pressed for more than the specified time,
In step #38, a switching signal is sent to the auto/manual switching circuit 66 to switch the mode between the auto offset adjustment mode and the manual offset adjustment mode. Then, in step 139, the flag 0 in the RAM 82
Rewrite H-FLAG. This flag 0W-FLAG
is a flag indicating which state is currently in among the three states: auto offset adjustment mode, manual offset adjustment mode, and manual offset-window adjustment mode. Then step 11
40, text information indicating the current state is displayed on the screen based on the value of this flag (V-FLAG), and step #
Return to 5. Note that in step 116, this flag is set to 0H.
- Area on the screen based on the value of FLAG (Fig. 12)
The item value (see a) is made to blink to notify the operator that offset adjustment or window adjustment is currently possible with the +/- keys 58.

If the ○/W key 57 is pressed but not kept pressed for a predetermined period of time, the flag is set to 0 in step #41.
The value of W-FLAG is used to check whether the current state is the auto offset adjustment mode. If it is the automatic offset adjustment mode, the process returns to step #5 without performing any processing, but if it is not, the process proceeds to step #39, where the transition between the manual offset adjustment mode and the manual offset-window adjustment mode is performed. The flag 0W-FLAG is rewritten so that the mode is switched.

・+/- key If the pressed key is the +/- key 58, the process advances to step I42 of the routine in FIG. 9(g), and the flag 0H is set.
By checking the value of -FLAG, it is determined whether the current mode is to adjust the offset or adjust the window. (Manual) If in offset i adjustment mode, step #4
At step 3, the offset is changed upward or downward by outputting a clock pulse to the counter 68, and at step 144, the character generator circuit 51 is used to change the offset on the screen to indicate that the offset is currently being changed. A character display rOFMtj or "○FM↓" to that effect is displayed in the area ■. and,
In step 1145, it is checked whether the +/- key 58 is still being pressed, and if so, the process returns to step #43 to continue offset circumference adjustment. When this key 58 is no longer operated, the stainless steel 714
Proceeding to step 6, the output of the clock pulse is stopped to finish changing the offset, the character display on the screen is also cleared, and the process returns to step 15.

If it is determined in step 142 that the current mode is window adjustment mode, in step 147 the gain of the amplifier 36 is changed or the range filter 70 is switched;
In step 148, characters to that effect are displayed in area (3) on the screen. In step #49, as before, this +/-
It is checked whether the key 58 continues to be pressed, and if so, steps #47 to #149 are repeated; if not, the window change is stopped in step 150 and the process returns to step 115.

1 function selection key If the pressed key is the function selection key 54, the process proceeds to step 51 in FIG. 9(h), and the RAM 8
Change the value of flag DSP-L in 2. This flag D
SP-L represents the selected function item, and the current emissivity can be changed with this value (DSP-L・
0), the temperature value stored in the RAM 82 can be displayed (DSP-L=1), and the temperature measurement mode can be changed (DSP-L=2). Show what you can do. The value of this flag DSP-L is used in the blinking display on the screen in step +16, and determines which item will be changed when the up/down key 55 is operated.

・Up/down key If the pressed key is the up/down key 55, the process advances to step #52 in FIG. 9(i) and the flag D is set.
It is checked whether the value of SP-L is O.

If DSP-L.0, the emissivity is increased or decreased in step 153, and in step +154, the changed emissivity value is displayed in area (3) on the screen, and the process returns to step #5.

When DSP-L is not O, in step 155 DSP-L is not set to O.
Check whether DSP-L is 1, and if DSP-L is 1, the temperature value etc. stored in the RAM 82 is displayed on the screen in step #56 (see FIG. 12(b)). Then, in step 1159, a check is made to see if the up/down key 55 has been pressed again, and the process waits in step 1155 until it has been pressed. When pressed again, the process returns to step R5.

If DSP-L is not 1, then DSP-L is 2, so the temperature measurement mode is changed in step #58.

Temperature measurement modes include an instantaneous value measurement mode that calculates the value at a certain moment, an average value measurement mode that calculates the average temperature within a predetermined time (for example, 0.5 seconds, 2 seconds, etc.), and a There are three modes: a peak value measurement mode that takes the peak value. In step #5, the three modes are sequentially switched. And step 115
Press 9 to display the characters of the switched mode in the area on the screen■
Then, return to step i5.

The above is an explanation of the processing executed by the CPU 52 after the power is turned on to the present device 10. In addition, the CPU 52
The routine shown in FIG. 10 is processed every time the polygon mirror 24 rotates once (this can be detected by the output of the photosensor 40). When entering this routine, first in step 170, the current
Check whether offset changes have been made.

In the automatic offset adjustment mode, it is possible to determine whether the offset has been changed by checking whether the value of the count value DOF changes from the previous value during the execution of the routine shown in Figure 9, and in manual offset adjustment. If it is the mode, it can be determined by checking whether the +/- key 58 is pressed. If the offset has not been changed, in step 1171, the value of the flag FRZ is 2 (real-time temperature measurement mode).
It is checked whether or not it is 2, and if it is not 2, this routine is ended. Proceed to step 172 only when FRZ=2,
In order to sample the signal output from the preamplifier 36, a sampling pulse is output to the sample hold circuit 75.

Then, in step 1173, the sampled signal is converted into a digital signal by the A/D converter 77, and as described above, the sensitivity signal of the detector 28 and the temperature sensing element 7 are
The signal from 8 is also A/D converted and multiplexed to the CP
Take it into U52. In step +174, the temperature of the object to be measured is calculated based on these three values, with correction made using the temperature signal from the temperature sensing element 78, and in step 76, the temperature value is displayed on the screen using the character generation circuit 51. Display in text.

If it is determined in step #70 that the offset is being changed, the process proceeds to step 1177, where the offset value DOF is fetched and the corresponding TV
Calculate line number LN. Then, in step #78, the address of the image memory 38 corresponding to the line number LN is calculated, and in step #79, mark data (rotoooooBJ in the above example) is written to the address, and this routine ends.

In this way, the current offset level is displayed on the screen at the same time as the infrared image in an easy-to-understand manner.Next, as another embodiment, an example in which the speed of offset change is changed depending on the gain will be described.

The reason for doing this is as follows. When the gain of the amplifier 36 is small, as shown in FIG. 16(a), A
The amplitude of the signal input to the /D converter 37 is generally small, and the temperature distribution of the object to be measured (temperature difference at each part) is shown on the screen.
cannot be read in detail. Therefore, if you want to display finer temperature differences on the screen (increase resolution), the first
6. Increase the gain of the amplifier 36 as shown in FIG. 6(b). By the way, as mentioned above, the offset adjustment is performed by sending a clock pulse to the counter 68 and checking the count value D.
This is done by changing the OF. This count value D
Changes in OF (that is, changes in offset level) are also amplified by the amplifier 36, so if the frequency of the clock pulse is constant regardless of the gain, when the gain is small (Fig. 16 (a)) When the gain is large within the same time as the time when it changes from to B (Fig. 16 (b)
)) changes greatly from A' to B'. Therefore, when the gain is large, the level of the infrared image may rapidly shift from black to white (or from white to black) in a short period of time, and the screen may jump to white (or black).

In addition, in the auto offset adjustment mode, it takes Vf for the output of the amplifier 36 to be taken out as its average voltage, so the change in the offset amount is stopped after determining that this average voltage has reached a predetermined value. However, in reality, it does not stop at the predetermined value, but exceeds the predetermined value. For example, in the case where the average voltage is adjusted to be between the reference voltages Va and vb, the average voltage is smaller than vb,
When increasing the offset amount, the actual average voltage of the output of the amplifier 36 when the average voltage reaches vb is vb + α
becomes. This α is determined by the rate of change of the output of the amplifier 36 and the delay time described above. Therefore, the faster the rate of change of the output of the amplifier 36, that is, the larger the gain of the amplifier 36, the larger α becomes, and depending on the gain of the amplifier, vb+α may exceed Va. Then, the offset level causes oscillation, and the output of the amplifier 36 no longer falls between Va and vbO.

Therefore, in this embodiment, when the gain is large, the CPU
52 is designed to reduce the frequency of the clock pulses supplied to counter 68. By doing this, the larger the gain, the slower the offset level will automatically change, which will slow down the change in the output of the amplifier 36, so the above-mentioned oscillation will not occur in the auto offset adjustment mode. , offset adjustment becomes easier even in manual offset adjustment mode.

Furthermore, such adjustment of the offset change speed is +/-
By adopting the structure shown in FIG. 17 for the key 58, it is also possible to perform the operation manually (at the discretion of the operator). Although only the mechanism for tilting the key switch 90 in the 10th direction is shown here, a comb-shaped moving piece 91 with three different heights is provided below the key switch 90, and the moving piece 91 Each tooth is brought into contact with the fixed contact 92 in sequence.

The pulse generation circuit 93 sends to the CPU 52 a pulse with a frequency that changes according to the resistance value that changes depending on the number of contacts. In the CPU 52, depending on the frequency of this pulse,
The frequency of the pulse signal sent to the counter 68 is changed.

The flowchart in FIG. 18 shows the routine executed by the CPU 52 when the +/- key 58 is used, and steps #42 and #1 in the flowchart in FIG. 9(g).
Steps 142-1 to 142-3 are added between step 143. When it is determined in step #42 that the mode is offset adjustment mode, in step 142-1, the pulse generated by pressing down the key switch 90 is inputted from the generation circuit 93, and in step 1142-2, its frequency f1 is calculated. . Then, in step 142-3, the frequency f2 of the output pulse signal to the counter 68 is calculated from the input frequency fl using a predetermined conversion formula (or conversion table), and in step #43, the frequency f2 of the output pulse signal to the counter 68 is calculated.
2 to send out a pulse signal. As a result, the offset level is changed at a speed corresponding to the amount by which the key switch 90 is pressed. That is, if the operator wants to change the offset slowly, he can press the +/- key switch 90 lightly, and if he wants to change it quickly, he can press it deeply.

As explained above, according to the present invention, the offset level is displayed on the screen at the same time as the infrared image, making it very easy to adjust the offset level, and even if the infrared image changes, the offset level can be adjusted. It becomes possible to adjust to a constant value. In addition, the speed at which the offset level is changed is variable depending on the gain and the amount the switch is pressed.
It becomes easy to operate over a wide range of offset levels or to make small changes.

[Brief explanation of drawings]

Figures 1 (a) to (c) are claim correspondence diagrams of the present application, and Figure 2
The figure is an external view of a portable infrared imaging device that is an embodiment of the present invention, FIGS. 3(a) and 3(b) are a plan view and a front view of its grip section, and FIG. Fig. 5 is a diagram showing the operation pattern of this device, Fig. 6 is a diagram showing the principle of infrared photography of this device, and Fig. 7 (a)
) to (d) are electric circuit diagrams of this device, FIG. 8 is a connection diagram of various switches, FIGS. 9 (a) to (i) are flowcharts of routines regularly executed by the CPU of this device, and FIG. The figure is a flowchart of a routine executed by an interrupt every time the polygon mirror rotates, and Figures 11 (a) to (c) are pure CR.
A diagram showing an example of the initial screen that appears on T, Figure 12 (
a) to (d) are diagrams showing examples of infrared image adjustment screens, 13th
Figures (a) and (b) are diagrams explaining the correspondence between the offset indicator on the screen and the data in the image memory,
Fig. 14 is a timing chart showing the relationship between the signal from the infrared detector and the clamp pulse for offset clamping, Fig. 15 is an explanatory diagram showing the relationship between the A/D convertible range and the offset level, and Fig. 16 ( a), (b)
is an explanatory diagram showing the relationship between the magnitude of the gain and the offset level change speed, Figure 17 is a structural diagram of a switch that generates a pulse signal according to the amount of push, and Figure 18 is a diagram of the CPU when the switch is operated. It is a flowchart of operation. io... Infrared imaging device 12... Grip 4... Main body 16... Panteri back 1 day... CRT Pure 24... Polygon mirror 26... Infrared condensing lens 28... Multi Element infrared detector 53...Mode key 54...Functions selection key 55...Up/down key 56...VTR key 57...O/W key 58...+/- key 59... ...F/M key 60...W/B key 6E...Focus key

Claims (3)

[Claims] (1) In an infrared imaging device that scans the object to be measured two-dimensionally, receives infrared rays, and converts the intensity of the infrared rays into image data that should be gradated on the screen, when converting infrared rays to image data, means for changing an offset level defined as an infrared intensity to be converted to a predetermined reference density; and adding offset level display data to the image data so that the offset level is displayed on the screen simultaneously with the infrared image. An infrared imaging device comprising: means. (2) In addition to the above, the infrared imaging device according to claim 1, further comprising: means for changing a gain during conversion from infrared rays to image data; and means for changing a speed of changing the offset level in accordance with the gain. (3) In addition to the above, claim 1 further comprises: a key switch that outputs a signal according to the amount of depression; and means for changing the speed of change of the offset level according to the output signal from the key switch.
The infrared imaging device described.