TWI589154B - Surveillance camera and control circuit for controlling optical filter module of surveillance camera - Google Patents

Description

Surveillance camera and control circuit for controlling the filter module of the surveillance camera

The present invention relates to a control camera and a control circuit for controlling a filter module of a surveillance camera, and more particularly to a surveillance camera having an infrared filter and a control circuit for controlling a filter module of the surveillance camera.

In recent years, with the advancement of technology, surveillance cameras have been widely used for security surveillance. Surveillance cameras are an indispensable monitoring tool for personal safety and property protection in homes, businesses, government agencies, and even general public places.

The surveillance camera mainly produces a monitoring picture by the photosensitive element, but in the case of sufficient visible light (for example, daylight), the infrared light in the light causes the monitoring image generated by the photosensitive element to be reddish, and is actually seen by the human eye. The images are different, so most surveillance cameras will be equipped with infrared filters to filter out the infrared rays in the light, so as to avoid serious chromatic aberration in the monitoring.

In addition, in order to monitor around the clock, some manufacturers also provide surveillance cameras that can be taken at night. In night vision mode, in order to capture images that are invisible to the naked eye in a dark environment, the night vision camera generates a monitoring image by sensing infrared rays in the light, in order to avoid the above-mentioned infrared filter. The light film filters out the infrared rays to be sensed in the night vision state, and the monitoring image cannot be generated. The night vision camera will be further equipped with a driving module to set the infrared light between the lens and the photosensitive element in the night vision mode. The filter is temporarily removed from the photosensitive element to make it sensitive The component can smoothly sense the infrared rays and generate a nighttime monitoring picture; and when the night vision camera is in the non-night vision mode, the driving module drives the infrared filter again, so that the infrared filter is again disposed on the lens and the photosensitive element. between. The above-mentioned driving module generally includes an IR-Cut Filter Removable (ICR). However, in the prior art, when the operation of the infrared filter switch is to be controlled, two signals are required, one of which is used to activate the infrared filter switch, and the other is used to set the infrared filter. The switcher's switching direction, so the prior art still has some limitations in its use.

An embodiment of the present invention provides a surveillance camera. The surveillance camera includes a housing, an optical module, a photosensitive element, a filter module, and a control circuit. The optical module is used to guide light into the casing. The photosensitive element and the filter module are disposed in the casing. The photosensitive element is used to sense the light guided by the optical module to generate an image signal. The filter module includes a filter and a driving module. The filter is disposed between the optical module and the photosensitive element to attenuate light waves in a specific wavelength range of the light, and the driving module is used to drive the filter. The control circuit is used to control the driving module, and includes an input terminal, a delay circuit, and a logic circuit. The input terminal is used for inputting a direction control signal, wherein the direction control signal is used to set a driving direction of the driving module when driving the filter. The delay circuit is used to delay the direction control signal to generate and output a delay signal. The two input ends of the logic circuit are coupled to the input end and the delay circuit, and generate an enable signal by using the direction control signal and the delay signal. When the driving module is enabled due to the enabling signal, the driving module drives the filter to move in the driving direction according to the direction control signal, and when the driving module is not enabled by the enabling signal, the driving module stops. Drive the filter.

Another embodiment of the present invention provides a control circuit for controlling a filter module of a surveillance camera. The filter module of the surveillance camera includes a filter and a driving module, wherein the filter is used to attenuate light waves in a specific wavelength range of the light, and the driving module is used to drive the filter. control The circuit includes an input, a delay circuit, and a logic circuit. The input terminal is used for inputting a direction control signal, wherein the direction control signal is used to set a driving direction of the driving module when driving the filter. The delay circuit is used to delay the direction control signal to generate and output a delay signal. The two input ends of the logic circuit are coupled to the input end and the delay circuit, and generate an enable signal by using the direction control signal and the delay signal. When the driving module is enabled due to the enabling signal, the driving module drives the filter to move in the driving direction according to the direction control signal, and when the driving module is not enabled by the enabling signal, the driving module stops. Drive the filter.

In summary, the control circuit of the present invention can additionally generate an enable signal for activating and enabling the drive module of the filter module when only one direction control signal is received. Therefore, in the case that only one direction control signal is input, the driving module can not only determine the driving direction of the filter according to the direction control signal, but also control the driving module to be activated by the separately generated enabling signal. The length of time. Since only one direction control signal is input, the functions of "enable drive module" and "control filter switching direction" can be achieved, and the present invention has high flexibility in use.

100‧‧‧ surveillance camera

110‧‧‧Shell

120‧‧‧Optical module

130‧‧‧Photosensitive elements

140‧‧‧Filter Module

142‧‧‧Drive Module

144‧‧‧Filter

150‧‧‧Control circuit

151‧‧‧ input

152‧‧‧Delay circuit

154‧‧‧Logical Circuit

C‧‧‧ capacitor

D1, D2‧‧‧ direction

L _R ‧‧‧Light

R‧‧‧resistance

S _IMG ‧‧‧Image Signal

S _ICR ‧‧‧ Directional Control Signal

S _EN ‧‧‧Enable signal

S _D ‧‧‧delay signal

Fig. 1 is a schematic view showing the appearance of a surveillance camera according to an embodiment of the present invention.

Fig. 2 is a functional block diagram of the surveillance camera of Fig. 1.

Figure 3 is a functional block diagram of the control circuit and filter module of Figure 2.

Figure 4 is a timing diagram of the control circuit of Figure 3.

Fig. 5 is a circuit diagram showing a control circuit of a surveillance camera according to an embodiment of the present invention.

Please refer to Figures 1 to 3. 1 is a schematic diagram showing the appearance of a surveillance camera 100 according to an embodiment of the present invention. FIG. 2 is a functional block diagram of the surveillance camera 100 of FIG. 1, and FIG. 3 is a control circuit 150 and a filter module of FIG. A functional block diagram of group 140. The surveillance camera 100 includes a housing 110, an optical module 120, a photosensitive element 130, a filter module 140, and a control circuit 150. The optical module 120 is configured to guide the light L _R into the casing 110. The photosensitive element 130 and the filter module 140 are disposed in the casing 110. The photosensitive element 130 is configured to sense the light guided by the optical module 120 to generate the image signal S _IMG , and the generated image signal S _IMG can be transmitted to the related electronic device for related operations. The related electronic device may include, but is not limited to, a screen and a storage device, wherein the screen may display a monitoring screen according to the received image signal S _IMG , and the storage device is configured to store the monitoring screen.

As shown in FIG. 3 , the filter module 140 includes a filter 144 and a driving module 142 . The filter 144 is disposed between the optical module 120 and the photosensitive element 130 for attenuating light waves of a specific wavelength range in the light, and the driving module 142 is configured to drive the filter 144. In an embodiment of the invention, the filter 144 is an infrared filter for attenuating or blocking infrared rays in the light, but the filter in the present invention is not limited thereto. In other words, the filter 144 can vary differently depending on the purpose of the surveillance camera 100. For example, in other embodiments of the present invention, the filter 144 may be a visible light filter, an ultraviolet filter, etc., for attenuating or cutting off visible light, ultraviolet light having a specific wavelength range in the light... Wait.

The control circuit 150 is configured to control the driving module 142, and can enable the driving module 142 and control the operation of the driving module 142 when only one direction control signal S _ICR is received. The control circuit 150 includes an input terminal 151, a delay circuit 152, and a logic circuit 154. The input terminal 151 is used to input the direction control signal S _ICR , and the delay circuit 154 is used to delay the direction control signal S _ICR to generate and output the delay signal S _D . The direction control signal S _{ICR is} used to set the driving direction of the driving module 142 when driving the filter 144 to move the filter toward the direction D1 or D2. The two input ends of the logic circuit 142 are coupled to the input terminal 151 and the delay circuit 152 to generate the enable signal S _EN according to the direction control signal S _ICR and the delay signal S _D . In an embodiment of the invention, the driving module 142 is an electromagnetic driver for generating a magnetic force to drive the filter 144 when enabled by the enable signal S _EN . In addition, in other embodiments of the present invention, the driving module 142 may be another driver, such as a stepping motor or the like.

The driving module 142 determines the driving direction of the filter 144 according to the potential of the direction control signal S _ICR . Please refer to FIG. 3 and FIG. 4, and FIG. 4 is a timing chart of the control circuit 150 of FIG. When the direction control signal S _ICR is high, the driving module 142 drives the filter 144 to move toward the direction D1; and when the direction control signal S _ICR is low, the driving module 142 drives the filter 144 to move toward the direction D2. . It should be understood that the relationship between the driving direction and the potential of the direction control signal S _ICR can also be reversed, that is, in another embodiment of the present invention, when the direction control signal S _ICR is high, the driving module 142 is driven. The filter 144 is moved in the direction D2; and when the direction control signal S _ICR is at a low level, the driving module 142 drives the filter 144 to move in the direction D1. In addition, in the embodiment, when the enable signal S _EN is high, the driving module 142 is enabled; and when the enable signal S _EN is low, the driving module 142 is not enabled. When the driving module 142 is enabled, the driving module 142 drives the filter 144 to move in the driving direction according to the direction control signal S _ICR ; and when the driving module 142 is not enabled by the enabling signal S _EN , the driving module Group 142 then stops driving filter 144. Since the enable signal S _EN is not at a high potential for a long time, the drive module 142 can be prevented from being burnt due to prolonged activation.

Please refer to FIG. 5. FIG. 5 is a circuit diagram of the control circuit 150 of the surveillance camera according to an embodiment of the present invention. In the present embodiment, the delay circuit 152 of the control circuit 150 is a resistor-capacitor circuit including a resistor R and a capacitor C, and the logic circuit 154 of the control circuit 150 is a XOR gate. The two input ends of the logic circuit 154 are coupled to the input terminal 151 and the delay circuit 152 for performing a mutually exclusive or (XOR) logic operation on the direction control signal S _ICR and the delay signal S _D to output the enable signal S _EN . The truth table of the control circuit 150 of FIG. 5 is as shown in Table 1 below:

Here, H in Table 1 represents a high potential with a logical value of "1", and L represents a low potential with a logical value of "0".

In addition, it should be understood that the delay circuit 152 of the control circuit 150 can also be implemented by different circuits. For example, the delay circuit 152 may be a delay circuit including an oscillator and a flip-flop. The flip-flop may delay the direction control signal S _ICR according to the clock signal generated by the oscillator. To generate and delay the signal S _D .

In summary, the control circuit of the present invention can additionally generate an enable signal for activating and enabling the drive module of the filter module when only one direction control signal is received. Therefore, in the case that only one direction control signal is input, the driving module can not only determine the driving direction of the filter according to the direction control signal, but also control the driving module to be activated by the separately generated enabling signal. The length of time. Since only one direction control signal is input, the functions of "enable drive module" and "control filter switching direction" can be achieved, and the present invention has high flexibility in use.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

140‧‧‧Filter Module

142‧‧‧Drive Module

144‧‧‧Filter

150‧‧‧Control circuit

151‧‧‧ input

152‧‧‧Delay circuit

154‧‧‧Logical Circuit

D1, D2‧‧‧ direction

S _ICR ‧‧‧ Directional Control Signal

S _EN ‧‧‧Enable signal

S _D ‧‧‧delay signal

Claims (8)

A surveillance camera includes: a casing; an optical module for guiding light into the casing; and a photosensitive element disposed in the casing for sensing light guided by the optical module, A filter module is disposed in the casing, wherein the filter module includes a filter and a driving module, and the filter is disposed on the optical module and the photosensitive Between the components, and used to attenuate light waves of a specific wavelength range in the light, and the driving module is used to drive the filter; and a control circuit for controlling the driving module, the control circuit includes: an input The terminal is configured to input a direction control signal, wherein the direction control signal is used to set a driving direction of the driving module when driving the filter; and a delay circuit is configured to delay the direction control signal to generate and output a delay signal; and a logic circuit having two input terminals coupled to the input terminal and the delay circuit for generating a uniform signal according to the direction control signal and the delay signal; wherein the driving module is enabled by the enable signal and When enabled, the driving module drives the filter to move in the driving direction according to the direction control signal, and when the driving module is not enabled by the enabling signal, the driving module stops driving the filter. And the length of time during which the driving module is enabled due to the enabling signal is positively correlated with the length of time that the direction control signal is delayed by the delay circuit. The surveillance camera of claim 1, wherein the logic circuit is a XOR gate, and the two input terminals are coupled to the input terminal and the delay circuit for controlling the signal and the delay. The signal performs a mutual exclusion or (XOR) logic operation to output the enable signal. The surveillance camera of claim 1, wherein the delay circuit is a resistor-capacitor circuit. The surveillance camera of claim 1, wherein the drive module is an electromagnetic driver for generating a magnetic force to drive the filter when enabled by the enable signal. A control circuit for controlling a filter module of a surveillance camera, the filter module comprising a filter and a driving module for attenuating light waves of a specific wavelength range in the light. The driving module is configured to drive the filter. The control circuit includes: an input terminal for inputting a direction control signal, wherein the direction control signal is used to set the driving module to drive the filter. a driving direction; a delay circuit for delaying the direction control signal to generate and output a delay signal; and a logic circuit having two input terminals coupled to the input terminal and the delay circuit for controlling according to the direction The signal and the delay signal generate a consistent signal; wherein when the driving module is enabled due to the enabling signal, the driving module drives the filter to move in the driving direction according to the direction control signal, and when When the driving module is not enabled by the enabling signal, the driving module stops driving the filter; and the length of time and the direction in which the driving module is enabled due to the enabling signal This number is the length of time delay circuit delaying a positive correlation. The control circuit of claim 5, wherein the logic circuit is a XOR gate, and the two input terminals are coupled to the input terminal and the delay circuit for controlling the signal and the delay. The signal performs a mutual exclusion or (XOR) logic operation to output the enable signal. The control circuit of claim 5, wherein the delay circuit is a resistor-capacitor circuit. The control circuit of claim 5, wherein the driving module is an electromagnetic driver for When the enable signal is enabled, a magnetic force is generated to drive the filter.