JPH0326503Y2 - - Google Patents

Description

[Detailed explanation of the idea] (Industrial application field) The present invention relates to the field of surveillance cameras.

(Prior art) Surveillance cameras are mainly installed at entrances and exits, customer service counters, safes, etc. of financial institutions such as banks, and take pictures of the situation in a predetermined range manually or automatically at fixed time intervals as needed. The purpose is to obtain identification photographs of criminals and photographic evidence when crimes occur.

Conventional surveillance cameras have been configured to have a lens protection member such as transparent glass or a filter fixed to the front surface of a photographic lens, and to photograph a subject through the protection member.

(Problems to be Solved by the Invention) Therefore, if paint is applied to the protective member using a paint sprayer or the like, there is a risk that it will become impossible to take pictures and the camera will lose its function as a surveillance camera.

(Means for Solving the Problems) In view of the above-mentioned circumstances, the present invention provides a surveillance camera with the protective member inserted and retractable, receives external light through the protective member, and adjusts the brightness of the protective member. A first light-receiving element that generates an output corresponding to the brightness of the external light, and a second light-receiving element that receives external light from the side without passing through the protection member and generates an output corresponding to the brightness of the external light, detects the ambient light of the surveillance camera. and further, when the output of the first light receiving element is in an output range corresponding to a predetermined brightness or less, and the output of the second light receiving element is in an output range corresponding to a predetermined brightness or more. a control circuit that outputs an exit signal for the protective member and a shutter release signal when a release signal is present;
A drive circuit for driving the protection member in response to the exit signal and a shutter circuit for driving the shutter to open in response to the shutter release signal are provided, and the output of the second light receiving element corresponds to a predetermined brightness or higher. If the amount of light transmitted through the protective member falls below the reference value due to sabotage such as paint spraying and the output of the first light receiving element falls within the output range corresponding to a predetermined brightness or less, the release operation The protective member is moved out from the front surface of the photographic lens immediately before photographing, and then photographing is performed.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. 1 and 2 show an embodiment of the present invention. FIG. 1 is an internal configuration diagram of the present invention, and FIG. 2 is an electrical wiring diagram of the present invention.

As shown in FIG. 1, the surveillance camera of the present invention has a box-shaped body 3 whose upper surface is open and whose interior is partitioned into upper and lower parts by a horizontal base plate 2. A film winding mechanism, an electric circuit, etc. (not shown) are housed between the body 3 and the bottom surface of the body 3.

On the other hand, the space above the main plate 2 constitutes a magazine mounting section 5 into which a magazine 4 loaded with films is mounted from an open upper surface of the body 3.

At the center of the front end of the top surface of the main plate 2, a frame 8 is provided which houses a first sprocket 6 for film feeding and a second sprocket 7 for checking film feeding. A screen window of a predetermined size and a guide rail are provided on the back surface of the frame 8, and between the guide rails, some of the teeth of the first and second sprockets 6 and 7 protrude to the outside.

A lens barrel 10 equipped with a photographic lens is provided on the front surface of the frame 8, and a first light receiving element 11 is provided on the outer periphery of the lens barrel 10.

A rotary solenoid 12 is provided at the tip of the curved portion 2a of the base plate 2, and a protection member 13 having a light transmitting property is fixed to the shaft of the solenoid.
The protective member 13 is normally located at the solid line position in FIG. 1, and external light passes through the protective member 13 to the first light receiving element 1
1 and the lens barrel 10, but when the rotary solenoid 12 is driven, the protective member 13 rotates clockwise and exits the photographing optical path of the lens barrel 10, and moves to the position of the imaginary line 14. conduct.

A take-up shaft 16 for winding up the film in the magazine 4 is provided within the opening 2b of the base plate 2.

An opening 3b is formed on the side surface of the body 3, and a second light receiving element 15 is provided for observing external light through the opening 3b.

In FIG. 2, the non-inverting input terminal + of the comparator 17 is connected to the sliding terminal T1 of the sliding resistor 18, and the inverting input terminal - is connected to the resistor 1 whose one end is connected to the positive bus bar.
9 and the first light receiving element 11 at a connection point T2. The non-inverting input terminal + of the comparator 20 is connected to the sliding terminal T3 of the sliding resistor 21, and the inverting input terminal - is the connection point between the resistor 22, whose one end is connected to the positive bus of the power supply, and the second light receiving element 15. Connected to T4. The output terminals of the comparators 17 and 20 are respectively connected to the input terminals of the exclusive OR circuit 23, and the output terminal of the exclusive OR circuit 23 is connected to the first input terminal T5 of the AND circuit 24. The other input terminal T6 is connected to a release mechanism (not shown) to which a release signal is input every time a photograph is taken. The output terminal of the AND circuit 24 is connected to a drive circuit 25, and the drive circuit 25 drives the rotary solenoid 12 for a certain period of time based on the H output of the AND circuit 24.

The movable section of the switch 26 is connected to the input end of a shutter circuit 27, which receives a release signal or an output signal from the AND circuit 24 and operates in synchronization with the drive of the rotary solenoid 12.

When the winding circuit 28 receives a shutter closing signal from the shutter circuit 27, it drives a motor (not shown), causes the first sprocket 6 to feed the film, and the second sprocket 7 to count the amount of film feed, and to deliver a predetermined amount of film. This circuit stops winding when the film is fed. During this time, the shutter is set by a mechanism not shown.

The movable section of the switch 29 is connected to the positive bus of the power source, and when connected to the b terminal, the AND circuit 24 receives the H signal regardless of the presence or absence of the release signal.

Next, the operation of the present invention having the above configuration will be explained.

As shown in Figure 2, connect the switches 26 and 29 to the a terminal, adjust the sliding resistances 18 and 21, and
When <V1 and V4<V3 are set, the outputs of the comparators 17 and 20 both become H, and the output of the exclusive OR circuit 23 becomes L. Therefore, no matter what kind of release signal is input to the input terminal T6 of the AND circuit 24, the output of the AND circuit is L, the drive circuit 25 does not operate, and the protective member 13 is photographed as shown in FIG. Keep it inserted in the optical path.

On the other hand, the protection member 13 is coated with paint spray.
When the light transmittance of the first light receiving element 11 decreases, the resistance value of the first light receiving element 11 increases, and when V2>V1, the output of the comparator 17 is inverted and becomes L, and the output of the exclusive OR circuit 23 is inverted and becomes H. becomes. Here, when the release signal is input as H, the output of the AND circuit 24 becomes H, the drive circuit 25 operates, the rotary solenoid 12 is driven, and the protection member 13 exits from the photographing optical path. In synchronization with this, shutter circuit 2
7 drives a shutter (not shown) to take pictures. When the shutter close signal comes in, the hoisting circuit 2
Reference numeral 8 drives a motor (not shown) to feed the film through the first sprocket 6. 2nd sprocket 7
When a predetermined amount of film has been transferred, the motor is stopped.

When switches 26 and 29 are connected to the b terminal,
The second input terminal T6 of the AND circuit 24 becomes H,
Drive circuit 25, shutter circuit 27 and hoisting circuit 2
8 is driven by the H output of the exclusive OR circuit 23. Now, by applying paint spray,
The light transmittance of the protective member 13 decreases, and the first light receiving element 1
When the resistance value of 1 increases and V2>V1, the outputs of comparator 17 and circuit 23 are inverted, and AND circuit 2
4 becomes H, the rotary solenoid 12 is driven by the drive circuit 25, the protection member 13 is moved out of the photographing optical path, the shutter is operated by the shutter circuit 27, and the winding circuit 28 is activated by the shutter close signal.
is driven. This series of operations will be performed continuously.

In addition, in this embodiment, when the surroundings of the set surveillance camera as well as the photographic field of the surveillance camera become dark, V2>V1 and V4>V3 will hold regardless of whether or not the protective member 13 is coated with paint spray. There is. In this case, the outputs of the comparators 17 and 20 are both L, the output of the exclusive OR circuit 23 remains in the L state, and even if the protective member 13 is coated with paint spray, the output of the comparator 17 remains unchanged. The protection member 13 is not withdrawn.

In this way, when the brightness around the surveillance camera changes, it may occur during daytime business hours at banks, etc. In this case, the amount of artificial lighting such as electric lights,
Indoor brightness is determined by the sum of the amount of outside light coming in through the window, so the total amount of light inside the room changes depending on the amount of change in indoor lighting and the amount of change in incident outside light.

Therefore, there is a possibility that the comparators 17 and 20 will be inverted at the darker limit value due to the amount of change.

However, there is little chance that paint sprays will be applied during business hours.

The intruder trying to apply the spray does not face the camera lens before applying the spray.
This is because a person who approaches the camera from outside the camera's field of view and engages in suspicious behavior is likely to be discovered in advance.

Therefore, since it is not possible to use a coating spray during the day, there is no problem even if both comparators 17 and 20 are inverted.

However, at night when no one is around, an intruder can easily enter from outside the camera's field of view, so if the protective material is applied, it is necessary to remove the protective material using the comparator 17 and take a picture. . At night, there is no incident external light and processing is performed using only indoor light, so there is no need to consider wide variations in illuminance.

Therefore, even in that indoor light, comparators 17 and 2
Of course, it is sufficient to set V2<V1 and V4<V3 so that 0 is not inverted.

(Effects) As explained above, the present invention provides a protective member having a light transmitting property so that it can be inserted and withdrawn from the front surface of the photographing lens, and a first lens that receives external light through the protective member.
Observing external light with a light receiving element and a second light receiving element that receives external light from the side without passing through the protective member,
When the output of the first light receiving element is in an output range corresponding to a predetermined brightness or less, and the output of the second light receiving element is in an output range corresponding to a predetermined brightness or more, and the release signal is When present, insertion and withdrawal of the protective member is controlled by a control circuit that outputs an exit signal and a shutter release signal for the protective member, so that the output of the second light receiving element is within an output range corresponding to a predetermined brightness or higher. If this is the case, even if the protective member is coated with paint spray, it is possible to photograph the protective member after leaving the protective member using a release signal, which has a very great practical effect.

[Brief explanation of drawings]

FIG. 1 is an internal configuration diagram of the present invention, and FIG. 2 is an electrical wiring diagram of the present invention. 2...Main plate, 3...Body, 4...Magazine,
5...Magazine attachment part, 6...First sprocket, 7...Second sprocket, 8...Frame body, 10
... Lens barrel, 11 ... First light receiving element, 12 ... Rotary solenoid, 13 ... Protective member, 15 ... Second light receiving element, 16 ... Winding shaft, 17, 20 ... Comparator, 23 ... ...exclusive OR circuit, 24...AND circuit, 25...drive circuit, 26...switch,
27...Shutter circuit, 28...Hoisting circuit, 29
...Switch.

Claims (1)

[Scope of Claim for Utility Model Registration] A light-transmitting protective member provided in the front surface of a photographic lens so as to be insertable and removable, and receiving external light through the protective member and generating an output corresponding to the brightness of the light. a first light-receiving element; a second light-receiving element that receives external light from the side without passing through the protective member and generates an output corresponding to the brightness thereof; outputs of the first light-receiving element and the second light-receiving element; When receiving a release signal, the output of the first light receiving element is in an output range corresponding to a predetermined brightness or less, and the output of the second light receiving element is in an output range corresponding to a predetermined brightness or more. a control circuit that outputs an exit signal and a shutter release signal for the protection member when a release signal is present; a drive circuit that receives the exit signal and drives the protection member; and a drive circuit that receives the shutter release signal and releases the shutter. A surveillance camera comprising a driving shutter circuit.