JPS61228320A - Apparatus for indicating measuring position of radiation thermometer - Google Patents

Abstract

PURPOSE:To eliminate the necessity for using a halogen lamp or an electronic flash apparatus having large quantity of light, by constituting the titled apparatus so that the brightness of the specific wavelength region around a measuring part is made high and the measuring part can be clearly indicated by the difference of contrast even if the circumference is light enough. CONSTITUTION:The light emitted from a light projecting element 16 passes through the aperture part 6a of a concave mirror 6 and is converged by a condenser lens 18 to be incident to a focus plate 8 and reflected by the reflective surface 8a of said focus plate 8 while the reflected light is again reflected by the reflective part 6b of the concave mirror 6 to form a ring shaped illumination spot around a measuring part. A finder 22 having wavelength selectivity is provided to a finder 20 and, for example, when a red LED with a specific wavelength is used as the light projecting element 16, a long wavelength transmission type filter for blocking or attenuating the specific wavelength light thereof is used as the finder 22 having wavelength selectivity. When an observing region is observed by said filter, the contrast of the region A corresponding to the observing region and the region B in the periphery of said region A with the illumination spot C becomes large and visibility becomes easy even if the circumference is light enough.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a radiation thermometer, and more particularly to a device for indicating the measurement position of the thermometer to a user.

2. Description of the Related Art Conventionally, an apparatus is known in which a spot is projected from the apparatus toward a measurement position, and the measurement position is indicated by the user viewing the spot.

However, such a device has a drawback that the spot becomes difficult to see if the area around the measurement position is bright. Therefore, in order to make the spot even brighter, some methods use a halogen lamp or a high-power electronic flash device as a light source, but the light source has a short lifespan, generates high heat, and consumes a large amount of power. A new drawback arises:

Therefore, there has been no device that can clearly indicate the measurement position even in bright surroundings without causing such drawbacks.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus that can clearly indicate a measurement position even if the surrounding area is bright, and that does not require the use of a halogen lamp or a high-power electronic flash device.

Means for Solving the Problems In order to achieve the above object, the present invention receives infrared light from a measuring section via a measuring optical system by a light receiving element, and adjusts the radiation of the measuring section according to its output. In a radiation thermometer that measures temperature, there is a finder for observing the measurement area including the measurement part, and a light projection means for projecting light around the measurement part via the measurement optical system to indicate the measurement part. and a wavelength selection means disposed within the finder optical path for reducing transmission of other wavelength components compared to the wavelength components contained in a large amount in the projected light.

Therefore, according to the present invention, in the finder display, the contrast between the measurement instruction section and other parts is increased and displayed.

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view showing a radiation thermometer according to an embodiment of the present invention, and in the figure, (2) is the radiation thermometer main body.

The incident light that enters the main body (2) from the measuring section is transmitted through the protective filter (4) and is reflected by the reflecting section (6b) of the concave mirror (6) having an opening (6a) formed on the optical axis (Xi). A focus plate (8) is located near the image forming surface of the concave mirror (6).
The focus plate (8) has a pinhole (
8a). Therefore, among the light reflected by the concave mirror (4), the pinhole (8a) of the focus plate (8)
Only the light that passes through the light is sent to the light receiving element (14) via the chopper (12) rotated by the motor (10).
is made to be incident on. Here, the chopper (12) is for converting the amount of light incident on the light receiving element (14) into an alternating current signal. The concave mirror (2) and the focus plate (8) constitute a measurement optical system, and the range measured by the measurement optical system is determined by the size of the pinhole (8a) of the focus plate (8). .

Note that the output of the light receiving element (14) is input to an arithmetic circuit (not shown) and used to measure the radiation temperature of the measuring section.

(16) is a light emitting element placed on the optical axis (optical axis), and the light emitted from the light emitting element (16) passes through the opening (6a) of the concave mirror (6) and passes through the condenser lens (18). ) i is thus focused and made incident on the reticle (8). The reticle (8) has a conical reflecting surface (1) around the pinhole (8a), the diameter of which gradually increases by 1 towards the concave mirror (6).
8b) is formed in one piece, and reflects the incident light from the light projecting element (6) towards the reflecting part (6t) of the concave mirror (6), and the focus plate (8). Reflective surface (8b)
Black plates are attached to other parts to prevent light from reflecting. Therefore, the light emitted from the light projecting element (16) passes through the opening (6a) of the concave mirror (6), is focused by the condenser lens (18), and is focused by the focusing plate (8).
), which is reflected by the reflecting surface (8b) and reflected again by the reflecting part (6b) of the concave mirror (6), and is projected onto the measuring area so as to surround the measuring part. That is, on the object to be measured, a ring-shaped illumination spot is formed around the measuring section by the light from the light projecting element (16). This is because the reflective surface (8b) of the focusing plate (8)
The optical path of the light that is reflected by the concave mirror (6) and projected onto the measurement area is reflected by the reflection part (6b) of the concave mirror (6), passes through the pinhole (8a) of the focus plate (8), and passes through the light receiving element (
This is because it is extremely close to the optical path of the measurement light incident on 14).

(20) is a finder rotatably supported in the center near the rear end of the earthen wall (2a) of the radiation thermometer body (2) as shown in the figure, and a filter having wavelength selectivity inside the finder. (22) is provided. This finder (20)
When not in use, the earth wall (2a,
) is stored in the recess. Here, the wavelength selectivity of the filter (22) is determined according to the emission wavelength of the light projecting element (16). For example, the center wavelength of the light projecting element (16) is 6.
When using 60nm red LED, filter (22)
As a filter, a long-wavelength transmitting glass or plastic filter that blocks or reduces short-wavelength light of 600 nm or less is used. Configure like this [
Therefore, when observing the measurement area using the finder (20), as shown by the two-dot chain line in FIG. Compared to the ring-shaped illumination spora) fc), there are many long wavelength components, so the contrast between fA) Pl and fc) is larger than it actually is, so the measuring part can be clearly seen regardless of the surrounding brightness. can.

Furthermore, when a red LED is used as the light emitting element (16) as in the above embodiment, the LED generates little heat, has a long life, consumes little power, and is inexpensive, so it is not suitable for halogen lamps or high-intensity lamps. The above-mentioned disadvantages of using an electronic flash device do not occur. Furthermore, since LEDs have good responsiveness,
The chopper (12) is synchronized with the rotation of the chopper (12).
It is also possible to turn on the light only when light is blocked by the light so as not to affect photometry, or it is also possible to turn on the light in pulses to make visual recognition easier.

Furthermore, in FIG. 1, (2b) is a grip fixed to the lower part of the main body (2), and the grip (2b) is provided with a pressable measurement button (24).

The measurement button (24) controls the power supply switch (26) and measurement switch (28) by pressing it, and the functions of each switch will be described below along with their operations. First, when the measurement button (24) is pressed to the first step, the contact piece (26a) of the power supply switch (26)
and (26b) are brought into conduction, power supply to the motor (10) is started, and the chopper (12) is rotated (7).At the same time, the contact piece (26a) and ( 26C), thereby supplying power to the light emitting element (I6) and forming an illumination spot around the measuring section.Therefore, in this state, look through the viewfinder and enter the desired object into the measuring section. You can adjust the direction of the radiation thermometer to aim it.

After aiming, push the measurement button (24) to the second step. Then, the contact piece (26C) of the power supply switch (26) is pushed and becomes disconnected from the contact piece (26a), and the light emitting element (16) is turned off or the contact piece (26a) and (26b) Since it remains conductive with the chopper (12
) continues to rotate. At about the same time, the measurement switch (
28) is closed, a photometric calculation circuit (not shown) is activated, and the radiation temperature is calculated from the photometric output of the light receiving element (14) and displayed on a display element (not shown).

In this embodiment, the finder (20) is located at the observation position shown by the solid line in order to prevent the light emitting element (16) from being lit when the finder (20) is in the storage position shown by the two-dot chain line. A separate switch is provided that closes when the
6b) in parallel, and the contact piece (26b) and (
26C) may be connected in series.

With this configuration, the light emitting element (16) is turned on only when the finder (20) is at the observation position, and turned off when performing photometry by pressing the measurement button (24) to the second step. This eliminates unnecessary lighting.

FIG. 3 is a sectional view of a main part showing a modification of the above embodiment. In the modification, the pinhole (8) of the focus plate (8)
As the reflecting surface in a), instead of the conical slope, a curved surface (8C) in which the slope is concave toward the concave mirror (6) is used. With this configuration, the light projecting element (16
) is focused by the condenser lens (18) and further focused by the reflective surface (8C) of the focus plate (8), so the illumination spot is as shown by the solid line in FIG. The illumination spot is formed in a narrower range than the illumination spot of the previous embodiment shown by the two-dot chain line, and is brighter than that of the previous embodiment. Therefore, the contrast with other parts becomes larger, and the measuring part can be more easily recognized. Furthermore, in the previous embodiment, it is impossible to accurately indicate the measurement unit unless the angle of the planar reflective surface (8b) is precisely formed, whereas in the modified example shown in FIG. Since a certain angle always occurs somewhere on a curved surface, the precision of the angle is not required for flat surfaces, which can reduce costs.

FIGS. 4, 5, and 6 are a side view and a sectional view showing essential parts of another embodiment of the present invention. This embodiment is characterized in that the wavelengths of the light projecting element and filter are changed between high temperature measurement and low temperature measurement. Note that the unillustrated portions of the radiation thermometer are the same as those in FIG. 1 and are therefore omitted.

In Fig. 4, (30) is the side wall (2C) of the main body (2).
The operating member is rotatably supported by a shaft (32) and has an index (30a). Now, when the index (30a) is set to the index "L-ON" as shown in FIG. 4, the red LED (34) that emits red light with a center wavelength of 660 nm can be lit. A red transmission filter (36a) that blocks light with a wavelength of 600 nm or less and transmits only red light is positioned at the observation position in the finder optical path.Here, the red L E D
(34) is arranged on the optical axis (X) of the concave mirror (6), as shown in the longitudinal sectional view of FIG. Furthermore, the red transmission filter (36a) is secured to one end of a first filter member (36) shown in the cross-sectional view of FIG. It is rotatably supported and has a pin (36b) at the other end.
has been planted.

(40) has a blue-green transmission filter (40a) that transmits blue and green light fixed to one end, and a pin (40b) to the other end.
) is implanted in the second filter member, which also has a shaft (38).
It is rotatably supported on the shaft. Then, the operation member (30
) When the indicator (30a) is aligned with the indicator "L-ON", it is in an unused position housed inside the main body (2) as shown in FIG. The first and second filter members (36) and (40) are rotated clockwise in FIG. 6, that is, the main body (
2) is biased in the direction of storage.

In FIG. 5, (42) is a mirror supported on a shaft (44) so as to be rotatable between the solid line position and the two-dot chain line position, and is retracted from the optical axis (X) shown in the solid line. is biased to the upper position. The shaft (44) is pivotally supported by the inner wall (2C) of the main body as shown in FIG.
Furthermore, pins (46048) are implanted in the inner wall (2C) for abutting the mirror (42) to restrict its upper position and the lower position shown by the two-dot chain line in FIG.

Further, a communication member (50) is fixed to the shaft (44), and the communication member (50) is connected to a lever ('52) rotatably supported on the shaft (44) and a spring ( 54) in only one direction (the direction in which the mirror (20) is moved to the lower position).

Further, in FIGS. 5 and 6, an L-shaped filter operating member (56) and a mirror operating member (58) are respectively fixed to the shaft (32) to which the operating member (30) is fixed. The filter operation member (56) has a pin (56a) on its arm that can come into contact with the pin (36b) of the first filter member (36), and a pin (40b) of the second filter member (40) on its narrow arm. It has a pin (56b) that can come into contact with. On the other hand, the mirror operation member (58) has a lever at one end.
It has a pin (58a) that can come into contact with (52).

In FIG. 5, (60) is a flash discharge tube that emits light containing a large amount of light in the short wavelength range such as blue and green, and when the mirror (42) is in the downward position, the mirror (42)
The optical axis (Xl) is bent by

With the above configuration, the index (30a
) is wintered by the index “L-ONII,”
The pin (36t) of the first filter member (36) is pressed by the pin (56a) of the filter operation member (56), and the first filter member (36) is moved to the observation position shown in the figure against the force. While being held, the mirror (42) is not pressed by the mirror operating member (58), so it is positioned at the upper position shown. When the indicator (30a) is aligned with the indicator “L-ONII”, the red L
The power switch (not shown) of the ED (34) is closed, and the red LED (34) is connected to the measurement button (24).
is made to emit light by suppressing it. On the other hand, at this time, the power switch (not shown) of the flash discharge tube (60) is open. Therefore, in this state, an illumination spot is formed around the measurement section by the red light, and this is observed through the finder through the red transmission filter (36a), so the area around the measurement section is emphasized, making it easier to visually recognize the measurement section. Become.

Next, the index (30a) of the operating member (30) is set to the index IO.
When set to "N", the power switch of the red LED (34) remains closed, but the filter operation member (56) and mirror operation member (58) in FIG. Therefore, the first filter member (36) is rotated clockwise by the biasing force, and the red transmission filter (36a) is retracted from the finder optical path and housed in the main body (2). This is used when the measuring section can be visually recognized without using the red transmission filter (36) because the surrounding area of the measuring section is not so bright.

Further, rotate the operating member (30) counterclockwise to set the indicator (30a).
) to the index "OFF", the main measurement switch (not shown) of the radiation thermometer is opened and the red LED
(34) and the power switch of the flash discharge tube (6o) are also opened. Further, the filter operation member (56) and the mirror operation member (58) are both located at the positions shown by the two-dot chain line in FIG. Do not come into contact with the

Further rotate the operating member (30) counterclockwise to set the indicator (30a).
) or index l'H-ON〃, this rotation causes the pin (56b) of the filter operation member (56) to push the pin (40b) of the second filter member (40) and rotate it counterclockwise. and move the blue-green transmission filter (40a) to the observation position against the urging force. At the same time, due to this rotation, the pin (58a) of the mirror operation member (58) presses the lever (52) downward, and together with the lever (52), the mirror (42) is also moved to the fifth position by the biasing force of the spring (54).
The mirror (42) is pressed counterclockwise in the figure and lowered, and the lowering is prevented by the mirror (42) coming into contact with the pin (46), so that the mirror (42) is positioned at the lower position. In this state, only the power switch for the flash discharge tube (60) is closed, and the power switch for the red LED (34) is open. Therefore, the measurement button (
When 24) is pressed, the flash discharge tube (60) emits light, and the light is reflected by the mirror (20) located at the lower position, similar to the case of the red LED (34). The light is projected onto the measuring section. Therefore, a blue-green illumination spot is formed around the measuring section, and this is observed with a finder through a blue-green transmission filter (40a).
The area around the measurement part is highlighted, making it easier to see the measurement part.

Here, when the measurement part is relatively high temperature, the emitted light has many long wavelength components including red, so the flash discharge tube (60) with many blue-green components is used to instruct the measurement part. On the other hand, when the measurement part is relatively low temperature, there are almost no long wavelength components including red in the emitted light, so a long-life, low-power red LED with a large red component and a long life (
It is efficient to use 34) to instruct the measurement unit. Therefore, when measuring high temperature, the indicator (30a) of the operating member (30)
) to the index "H-ON".
When measuring low temperatures, it is best to measure according to the index "L-ON" or "ONII. Therefore, in this example,
Clear instructions are always possible regardless of the temperature of the measuring part.

Effects of the Invention As described above, the present invention provides a radiation thermometer that receives infrared light from a measuring section by a light receiving element via a measurement optical system, and measures the radiation temperature of the measuring section according to the output thereof. , a finder for observing the measurement area including the measurement part;
A light projection means that projects light around the measurement section through a measurement optical system in order to direct the measurement section, and a light projection means that is placed in the finder optical path and is used to detect other wavelength components that are contained in a large amount in the projected light. This device is characterized by having a wavelength selection means for reducing the transmission of wavelength components of
The contrast difference makes it possible to clearly indicate the measuring section even if the surroundings are bright, and there is no need to use a halogen lamp or a high-power electronic flash device.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing a radiation thermometer according to an embodiment of the present invention;
Figure 2 is a schematic diagram showing the illumination spot on the measurement target.
Fig. 3 is an enlarged sectional view of the main part showing a modified example, Fig. 4 is a surface survey of the main part of another embodiment, Fig. 5 is a vertical sectional view of the main part, and Fig. 6 is a cross-sectional view of the main part. It is a diagram. (61 (81: measurement optical system, (14): light receiving element,
(16) (18X8b) (80); Light projecting means, (20
) : Finder, (22) ; Wavelength selection means, (34
) (60); Light projecting means, (36a) (40a) Wavelength selection means Applicant: Minolta Camera Co., Ltd. No. 5riA $b Figure

Claims (1)

[Scope of Claims] 1. In a radiation thermometer that receives infrared light from a measuring section by a light receiving element via a measurement optical system and measures the radiation temperature of the measuring section according to its output, the measuring section a finder for observing the measurement area including the measurement area; a light projection means for projecting light around the measurement area via the measurement optical system to direct the measurement area; 1. A measurement position indicating device for a radiation thermometer, comprising wavelength selection means for reducing transmission of other wavelength components with respect to wavelength components contained in a large amount in the light. 2. The measurement position indicating device for a radiation thermometer according to claim 1, wherein the light projecting means includes a light emitting element that emits light in the specific wavelength range. 3. The measurement position indicating device for a radiation thermometer as set forth in claim 1, wherein the wavelength selection means comprises a filter that blocks light in the other wavelength ranges. 4. The measuring optical system includes a concave mirror that reflects infrared light from the measuring section so as to focus it, and a focusing plate that is placed near the focal plane and has an opening on the optical axis. 2. The measurement position indicating device for a radiation thermometer according to claim 1, wherein the element is arranged to receive infrared light transmitted through the opening. 5. The light projecting means emits light in the specific wavelength range, and is formed around the light emitting element arranged on the optical axis and the opening of the focus plate, and reflects the light emitted from the light emitting element toward the concave mirror. 5. The measurement position indicating device for a radiation thermometer according to claim 4, further comprising a reflecting means for reflecting the radiation thermometer. 6. Claim 5, characterized in that the reflecting means consists of a symmetrical conical reflecting surface that rotates about the optical axis.
Measurement position indicating device for the radiation thermometer described in Section 3. 7. Measurement position indication of the radiation thermometer according to claim 1, wherein the wavelength selection means is comprised of two filters that transmit different wavelength ranges and are selectively positioned on the finder optical path. Device. 8. The measurement position indicating device for a radiation thermometer according to claim 7, wherein the light projecting means is comprised of two light projecting elements that have different emission wavelength ranges and are selectively emitted.