JP2020095090A - Lens device and imaging device - Google Patents

Abstract

To provide a lens device advantageous for replacement of a desiccant, with which it is possible to determine the hygroscopic ability of the desiccant in its entirety or appropriate replacement time of the desiccant without having to remove the desiccant from inside of the lens device.SOLUTION: The lens device comprises a barrel 3, a lens 4 held by the barrel, a holding unit 6 for holding a desiccant 5 in the barrel, and a measurement unit 7 for measuring the weight of the desiccant, the lens device processing a replacement time on the basis of the weight of the desiccant and displaying it on a display unit 8. The measurement unit includes a first measurement unit for measuring a temperature and humidity and arranged inside of the barrel and a second measurement unit for measuring a temperature and humidity and arranged outside of the barrel, and a processing unit is included that obtains a replacement time on the basis of the results of measurement by the first and second measurement units. The display unit includes an elastic member that shrinks and extends in accordance with the weight of the desiccant, and a target that is movable in accordance with the telescopic motion of the elastic member, and is arranged in an exterior unit 2 or remote control unit of a lens device 1.SELECTED DRAWING: Figure 1

Description

The present invention relates to a lens device and an imaging device.

Due to the diversification of shooting, the temperature and humidity of the lens device may change, such as moving from a cool indoor environment to a hot and humid outdoor environment, or from a heated indoor environment to a cold outdoor environment such as a ski resort. It is also frequently used under rapidly changing conditions.

When used in such a situation, a temperature difference occurs between the outside temperature and the temperature inside the lens device. Further, due to this temperature difference, a pressure difference is generated between the inside and outside of the lens device, and when the inside of the lens device becomes a negative pressure with respect to the outside, hot and humid outside air may flow into the inside of the lens device through the gap of the lens device. The glass constituting the lens device has a relatively low thermal conductivity and is unlikely to change in temperature. Therefore, the hot and humid outside air that has flowed into the lens device is cooled to cause vapor to condense and may become cloudy.

Fogging of the glass (lens) due to such dew condensation can be reduced by lowering the humidity inside the lens device. Patent Document 1 discloses a technique of filling a desiccant in the lens device to reduce the amount of water vapor in the lens device. Patent Document 2 discloses that a band-shaped desiccant is arranged along the inner wall surface of the lens barrel, and a part of the outer periphery of the lens barrel is formed of a transparent member so that the desiccant replacement time can be visually confirmed. Is disclosed.

Japanese Patent No. 3248295 Japanese Patent No. 3824191

However, in the lens device of Patent Document 1, it is impossible to determine an appropriate replacement time unless the desiccant is taken out from the lens device. Further, in the lens barrel of Patent Document 2, since only a part of the band-shaped desiccant is visible, it is not possible to determine the moisture absorption capacity of the desiccant as a whole or an appropriate replacement time. An object of the present invention is to provide, for example, a lens device which is advantageous for exchanging a desiccant.

In order to achieve the above object, the lens device of the present invention includes a lens barrel, a lens held by the lens barrel, a holding unit for holding a desiccant in the lens barrel, and a replacement timing of the desiccant. And a display unit for displaying.

According to the present invention, for example, it is possible to provide a lens device that is advantageous for exchanging a desiccant.

Schematic diagram showing the entire lens apparatus in the first embodiment. Detailed drawing of the essential parts of the lens apparatus of the first embodiment. The figure showing operation|movement of the lens apparatus in 1st Example. Detailed view of the main parts during operation of FIG. Schematic showing the entire lens apparatus in the second embodiment. The figure showing the display of the lens operation part 11 of a 2nd Example. Schematic showing the entire lens apparatus in the third embodiment. Flowchart of operation in the third embodiment

Hereinafter, preferred embodiments of the lens device of the present invention will be described in detail with reference to the attached FIGS.

A lens apparatus 1 according to a first embodiment of the present invention will be described below with reference to FIGS.

(Constitution)
The overall configuration of the lens apparatus according to the first example will be described with reference to FIG.
FIG. 1 is a schematic view showing the whole lens apparatus 1 of the first embodiment of the present invention. The lens device 1 of the present embodiment is a weight measurement as an exterior part 2, a lens barrel 3, a glass part (lens) 4, a desiccant 5, a desiccant storage part (holding part) 6, and a moisture absorption capacity judging means (judging part). It is configured by a unit (measurement unit) 7. The exterior part 2 is mounted along the direction parallel to the optical axis 0. Here, the optical axis 0 refers to the optical axis of the lens device 1 of the present invention. The exterior part 2 is covered so as to surround the entire lens barrel 3 around the optical axis 0. The glass portion 4 is held inside the lens barrel 3. The desiccant storage portion 6 is attached by providing an opening for ventilation between the desiccant storage portion 6 and the inside of the lens barrel 3. The desiccant 5 and the weight measuring unit 7 are installed inside the desiccant storage unit 6. The exterior part 2 and the desiccant storage part 6 are provided with a display window 8 as a moisture absorption capacity display part.

The detailed configuration of the weight measuring unit 7 will be described with reference to FIG.
FIG. 2 is a detailed view of the essential parts of this embodiment. The weight measuring unit 7 includes a mounting table 7A on which the desiccant 5 is set (mounted), an elastic member 7B, and a scale (target) 7C. The elastic member 7B is attached between the lens barrel 3 and the mounting table 7A so as to hold the mounting table 7A against the gravity direction, and expands and contracts according to the weight of the desiccant 5 mounted on the mounting table 7A. .. In this embodiment, the elastic member 7B is arranged so as to be compressed according to the weight of the desiccant 5, but the elastic member 7B may be arranged so as to be expanded according to the weight of the desiccant 5. Since the scale 7C is fixed to the mounting table 7A, it can move as the elastic member 7B expands and contracts. A part of the scale of the scale 7C can be seen from the outside of the lens device 1 through the display window 8.

(Operation and effect)
The operation of the weight measuring unit 7 and the display of the display window 8 will be described with reference to FIGS. 3 to 4. In this embodiment, the mass of the desiccant 5 in the initial state is M0, the weight of the absorbed water vapor is ΔM (0<ΔM<M1-M0), and the weight of the desiccant 5 at the time of replacement is M1. Further, the spring constant of the elastic member 7B is k.

FIG. 3 is a diagram showing the operation of the lens device 1 in this embodiment. (A) shows the operation of the weight measuring unit 7 and the display of the display window 8 immediately after the replacement of the desiccant 5, (b) during the absorption of the desiccant 5, and (c) at the time of the replacement of the desiccant 5. FIG. 4 is a diagram schematically showing the positional relationship among the elastic member 7B, the scale 7C, and the display window 8 in each state of FIG.

Immediately after the desiccant 5 is replaced (when the desiccant 5 is new), the weight measuring unit 7 is in the state shown in FIG. Since the weight of the desiccant 5 is M0, the elastic member 7B is reduced by M0/k, and the mounting table 7A and the scale 7C are displaced in the gravity direction. At this time, the display window 8 displays that the moisture absorption capacity of the desiccant 5 is 100%.

After the replacement of the desiccant 5 until the replacement time, the weight measuring unit 7 is in a state as shown in FIG. 4B, for example. The desiccant 5 absorbs the water vapor in the lens device 1, so that the weight of the desiccant 5 increases. The weight of the desiccant 5 after absorbing moisture can be expressed as M0+ΔM, where ΔM is the weight of absorbed water. The mounting table 7A and the scale 7C are displaced by (M0+ΔM)/k in the direction of gravity. The scale 7C is provided with a scale and is displaced according to an increase in the weight of the desiccant 5. The life of the desiccant 5 can be determined by the scale displayed on the display window 8.

When it is time to replace the desiccant 5, the state shown in FIG. The weight of the desiccant 5 becomes M1, the mounting table 7A and the scale 7C are displaced by M1/k, and it is displayed on the exterior part 2 that the desiccant 5 has a moisture absorption capacity of 0%, and the desiccant 5 is replaced based on the measurement result. You can judge when.

Since the present invention uses the weight of the water vapor absorbed by the desiccant 5 as a means for determining the proper exchange time of the desiccant 5, the proper exchange time is determined based on the measurement result regardless of the ambient temperature and humidity environment. be able to.

When the initial weight and the weight at the time of replacement differ depending on the type of the desiccant 5, the replacement time of the desiccant 5 can be changed by changing the elastic member 7B having a different spring constant or changing the length of the scale 7C. The weight value of can be changed.

As described above, in the lens device of the present invention, the moisture absorption capacity of the desiccant and the appropriate replacement time can be determined by using the weight of the entire desiccant as the determination means.
By including the processing unit that obtains the desiccant replacement time based on the measurement result by the weight measuring unit (measurement unit) 7, it is possible to provide a lens device that is advantageous for exchanging the desiccant.

A lens apparatus according to the second embodiment of the present invention will be described below with reference to FIG. It should be noted that, in comparison with the first embodiment, the present embodiment further includes a desiccant hygroscopic capacity determination means and a hygroscopic capacity display section.

(Constitution)
The configuration of the lens device 1 will be described with reference to FIG.
FIG. 5 is a schematic view showing the whole lens apparatus 1 according to the second embodiment of the present invention. This embodiment is different from the first embodiment only in the moisture absorbent capacity determination means (determination section) and the moisture absorbent capacity display section of the desiccant. The moisture absorption capacity determining means in this embodiment is composed of the weight sensor 9 and the attitude difference sensor 10. An attitude difference sensor (not shown) is configured in the lens device 1 and can detect the attitude difference of the lens device 1. The weight sensor 9 is installed inside the desiccant container 6 and measures the force (gravity) acting in the vertical direction when the lens device 1 is arranged in a predetermined posture (for example, when the optical axis direction is horizontal). To do. Assuming that the attitude difference of the lens device 1 with respect to the horizontal direction is θ (0≦θ≦45°) and the measured value by the weight sensor 9 is M, the weight of the desiccant 5 when the attitude difference is θ is M/cos θ. It can be expressed as.

The lens operating unit 11 is provided so as to be connected to the lens device 1. The lens operating unit 11 is provided with a display 11A, and the weight of the desiccant 5 calculated by the weight sensor 9 and the attitude difference sensor 10 is fed back to the lens device 1 to display the moisture absorption capacity of the desiccant 5 on the display 11A. ..

(motion)
FIG. 6 is a diagram showing a display of the lens operating unit (remote operating unit) 11 of this embodiment. FIG. 6A is a view of the display 11A immediately after the desiccant 5 is replaced. FIG. 6B is a diagram of the display 11A from immediately after the replacement of the desiccant 5 to the replacement time. FIG. 6C is a diagram of the display 11A at the time of exchanging the desiccant 5.

In FIG. 6A, it is displayed that the moisture absorption capacity is 100%. In FIG. 6B, the moisture absorption capacity of the desiccant 5 during moisture absorption is displayed. In FIG. 6C, it is displayed that the moisture absorption capacity is lost and that replacement is required.

By feeding back the signal of the weight sensor 9 to the lens device 1 as described above, the moisture absorption capacity of the desiccant 5 is displayed on the display 11A, and it is possible to determine an appropriate replacement time.

Hereinafter, a lens apparatus according to a third embodiment of the present invention will be described with reference to FIG. It should be noted that, as compared with the first embodiment, the present embodiment refers to the desiccant hygroscopic capacity determining means and the hygroscopic capacity display section.

(Constitution)
The configuration of the lens device 1 will be described with reference to FIG. 7.
FIG. 7 is a schematic view showing the whole lens apparatus 1 according to the third embodiment of the present invention. This embodiment is different from the first embodiment only in the moisture absorbent capacity determination means (determination section) and the moisture absorbent capacity display section of the desiccant. The moisture absorption capacity determining means in this embodiment is composed of a temperature/humidity sensor 12A and a temperature/humidity sensor 12B. The temperature/humidity sensor (first measuring unit) 12A is installed in the desiccant storage unit 6 and measures the temperature and humidity in the desiccant storage unit 6. The temperature/humidity sensor (second measuring unit) 12B is installed outside the lens apparatus 1 (outside the lens barrel) and measures (measures) the temperature and humidity around the lens apparatus 1. The display unit 13 as a moisture absorption capacity display unit is configured in the exterior unit 2. The user replaces the desiccant 5 without directly checking the desiccant 5 by determining the replacement time based on the results (measurement results) measured by the temperature/humidity sensor 12A and the temperature/humidity sensor 12B and turning on the display unit 13. You can judge when.

(motion)
The operation and effect of this embodiment will be described below with reference to the flowchart of FIG.
In step 101, the temperature and humidity inside the desiccant container 6 are detected by the temperature and humidity sensor 12A, and the temperature and humidity around the lens device 1 are detected by the temperature and humidity sensor 12B, and the process proceeds to step 102. In step 102, it is determined by the value of the relative humidity whether the air in the desiccant container 6 is dry. When the relative humidity is equal to or lower than the predetermined value, the processing is ended. If the relative humidity is equal to or higher than the predetermined value, the process proceeds to step 103.

In step 103, the absolute humidity inside the desiccant container 6 is calculated from the temperature and humidity measured by the temperature/humidity sensor 12A, and the absolute humidity around the lens apparatus 1 is calculated from the temperature and humidity measured by the temperature/humidity sensor 12B. Proceed to. In step 104, it is determined whether the difference between the absolute humidity inside the desiccant container 6 and the absolute humidity around the lens device 1 is smaller than a predetermined threshold value. If it is not smaller than the predetermined threshold value, the process ends. If it is smaller than the predetermined threshold value, it is determined that the desiccant 5 has lost its hygroscopic ability, and the process proceeds to step 105. In step 105, the display unit 13 is turned on to show the user when to replace the desiccant 5. The above processing and determination are repeatedly executed at regular intervals.

From the above, it is possible to determine an appropriate replacement time for the desiccant.
Further, by configuring the image pickup apparatus including the lens apparatus described in the embodiments and the image pickup element arranged on the image plane of the lens apparatus, it is possible to realize the image pickup apparatus having the effects of the present invention.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof.

1... Lens device 3... Lens barrel 4... Glass portion 6... Desiccant storage portion 8... Display window (display portion)

Claims (9)

A lens barrel,
A lens held by the lens barrel,
A holding portion for holding a desiccant in the barrel,
A display unit that displays the time to replace the desiccant,
A lens device comprising: The lens device according to claim 1, further comprising a measuring unit that measures the desiccant. The lens device according to claim 1, wherein the display unit displays the replacement time based on the weight of the desiccant. The measuring unit measures the weight of the desiccant,
A processing unit for obtaining the replacement time based on a measurement result by the measuring unit,
The lens device according to claim 2, wherein: The measuring unit is
A first measuring unit arranged inside the lens barrel to measure temperature and humidity;
A second measurement unit arranged outside the lens barrel for measuring temperature and humidity;
Including,
A processing unit that obtains the replacement time based on the measurement results of the first measurement unit and the second measurement unit;
The lens device according to claim 2, wherein: The display unit is
An elastic member that expands and contracts according to the weight of the desiccant,
A target that is movable according to expansion and contraction of the elastic member,
The lens device according to claim 3, further comprising: The lens device according to any one of claims 1 to 6, wherein the display unit is arranged on an exterior portion of the lens device. The lens device according to any one of claims 1 to 5, wherein the display unit is arranged in a remote operation unit for operating the lens. A lens device according to any one of claims 1 to 8;
An image sensor arranged on the image plane of the lens device;
An image pickup apparatus comprising:

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