JPH0568185U - TV intercom device - Google Patents

Abstract

(57) [Summary] [Structure] The intercom subunit 11 is provided with an image sensor 15 for capturing an image of a visitor illuminated by a fluorescent lamp. The image sensor 15 is controlled by an image sensor control circuit 16 that controls the electronic shutter function. The control speed of the image sensor control circuit 16 is changed from the first control speed to the second speed according to the light and shade of the visitor illuminated by the fluorescent lamp.
Switch to the control speed of. The second control speed is selected so as to be synchronized with the frequency of the power source in which the fluorescent lamp is used, and the video signal generated according to the control speed is modulated by the video signal modulation circuit 13 and sent to the intercom base unit 1. The intercom base unit 1 demodulates the received video signal with the video signal demodulation circuit 5 and monitors it with the television monitor 6. [Effect] It is possible to reduce the flickering of the screen due to the illumination of the fluorescent lamp and obtain a clear video signal.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a TV intercom device, and in particular, a control speed changeover switch is provided in a doorphone handset equipped with an image sensor control circuit in which the control speed of the image sensor is changed according to the brightness of a visitor illuminated by a fluorescent lamp. The present invention relates to a TV intercom device that can reduce flickering of a screen caused by illumination of a fluorescent lamp.

[0002]

[Problems to be Solved by Prior Art and Invention]

As shown in FIG. 3, a conventional TV intercom device includes a microphone 38b, a speaker 38a, a call button 39, an intercom subunit 36 provided with an imaging window 37, a handset 32, a television monitor 34, and a function button 33. The doorphone master unit 31 is connected to the doorphone slave unit 36 by the transmission line L ₂ .

Normally, the image pickup window 37 is shielded by a smoke-shaped screen so that the inside cannot be seen, and an image pickup element is provided inside. The visitor SUB is illuminated by, for example, a fluorescent lamp FL of 50 Hz, and the image pickup element is controlled by the electronic shutter function according to the brightness level of the visitor SUB such as very bright, normal, slightly dark, and dark. The image sensor control circuit changes the control speed to 1/10000, 1/1000 to 1/200, 1/100, 1/60 per second. When the television scan is 1/60 in the NTSC system, the screen of the TV monitor 34 cannot be synchronized with the fluorescent lamp FL of 50 Hz when the control speed becomes 1/60 per second when the brightness of the visitor SUB is dark. There are difficulties such as flicker.

[0004]

[The purpose of the device]

 The present invention has been made in view of the above-mentioned drawbacks, and by providing a control speed switching switch in the intercom slave unit, it is possible to reduce the flicker of the screen due to the illumination of the fluorescent lamp and to obtain a clear video signal. The purpose is to provide a device.

[0005]

A TV door intercom device according to the present invention includes an image sensor for capturing a visitor illuminated by a fluorescent lamp, an image sensor control circuit for controlling the image sensor with an electronic shutter function, and an image sensor. A control speed changeover switch for changing the control speed of the electronic shutter function of the slave control circuit from the first control speed to the second control speed according to the brightness of the visitor illuminated by the fluorescent lamp, and the control speed changeover switch generated according to the control speed. A doorphone slave unit having a video signal modulating circuit for modulating a video signal that modulates the video signal, and a doorphone master unit for receiving the video signal modulated by the video signal modulating circuit of the doorphone slave unit. A video signal demodulation circuit for demodulating the received video signal and a television monitor for monitoring the video signal demodulated by the video signal demodulation circuit are provided.

[0006]

[Action]

 The control speed change-over switch installed on the intercom slave sets the control speed of the image sensor control circuit that controls the electronic shutter function of the image sensor that captures the visitors illuminated by the fluorescent light. The control speed is switched from the first control speed to the second control speed. The second control speed is selected so as to be synchronized with the frequency of the power supply in which the fluorescent lamp is used, and the video signal generated according to the control speed is modulated by the video signal modulation circuit and sent to the intercom base unit. The video signal demodulation circuit of the intercom base unit demodulates the video signal, and the demodulated video signal is monitored by the NTSC TV monitor whose TV scan is 1/60.

[0007]

【Example】

An embodiment of the TV intercom apparatus according to the present invention will be described in detail below with reference to FIGS. As shown in FIG. 1, the TV intercom apparatus according to the present invention includes a microphone 19b, a speaker 19a, a call button 20a, an imaging window 18, an intercom subunit 11 provided with a flicker reduction control speed switching switch 17, and a handset. 4, a TV monitor 6, and a doorphone master unit 1 having a function button 8. The doorphone slave unit 36 and the doorphone master unit 3 1 are connected by a transmission line L ₁ .

As shown in FIG. 2, the intercom base unit 1 includes a communication circuit 3 to which a handset 4 is connected, an intercom slave interface 2, a video signal demodulation circuit 5 to which a television monitor 6 is connected, and a function button 8. The inside of the intercom slave unit interface 2, which is composed of the connected intercom master unit CPU 7 and whose output side is connected to the terminal T ₁ , is connected to the call circuit 3 and the video signal demodulation circuit 5, which are controlled by the intercom master unit CPU 7, respectively. To be done.

The intercom slave 11 is connected with a call circuit 19 to which a microphone 19b and a speaker 19a are connected, a flicker reduction control speed changeover switch 17, an image sensor control circuit 16 having an electronic shutter function, and a call button 20a. Door phone slave unit CPU 20, image sensor 15 to which a video signal from an image capturing window 18 blocked by a smoke-shaped screen so that the inside cannot be seen, and an image signal to which the output side of the image sensor 15 is connected knitting circuit 14 is constituted by the video signal modulation circuit 13 and the doorphone master station interface 12, the delivery side is connected doorphone inner base unit interface 1 2 to the terminal T ₂ are respectively connected to the video signal modulation circuit 13 and the telephone circuit 19 It The control sides of the imaging element control circuit 16, the video signal organization circuit 14, the video signal modulation circuit 13, and the call circuit 19 are connected to the intercom slave CPU 20. Further, the output side of the image pickup device 15 is fed back to the image pickup device control circuit 16 in order to detect the brightness of the visitor SUB.

Here, the flicker reduction control speed changeover switch 17 is not closed in an area where the frequency of the power source in which the fluorescent lamp FL is used is 60 Hz. If the flicker reduction control speed changeover switch 17 is not closed, the control speed is 1/10000 per second according to the brightness level of the visitor SUB such as very bright, normal, slightly dark, and dark. , 1/1000 to 1/200, 1/100, 1/60. When the video signal is monitored by the TV monitor 6 of the NTSC system whose TV scanning is 1/60, the control speed is 1/60 when the brightness of the visitor SUB is dark and the power frequency of 60 Hz at which the fluorescent lamp FL is used is 60 Hz. The screen is clear because it is synchronized.

The flicker reduction control speed changeover switch 17 is closed in a region where the frequency of the power source in which the fluorescent lamp FL is used is 50 Hz. When the control speed changeover switch 17 for flicker reduction is closed, the control speed is 1/10000 per second, depending on the brightness level of the visitor SUB such as very bright, normal, slightly dark, and dark. It is changed to 1/1000 to 1/200 and 1/100. When the brightness of the visitor SUB is 1/100, which is a little dark, the frequency of the power source used for the fluorescent lamp FL is twice the frequency of 50 Hz, so they are synchronized with each other, so flicker is reduced and the screen is clear.

If the television scanning system is the PAL system of 1/50 and the frequency of the power supply for the fluorescent lamp FL is 60 Hz, 1/100 may be changed to 1/120.

[0013]

[Effect of the device]

 Since the TV intercom device according to the present invention is provided with the control speed changeover switch for reducing flicker, it is possible to reduce the flicker on the screen due to the illumination of the fluorescent lamp and obtain a clear video signal.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a TV intercom device according to the present invention.

FIG. 2 is a block diagram showing an embodiment of a TV intercom device according to the present invention.

FIG. 3 is a block diagram of a conventional TV intercom device.

[Explanation of symbols]

1 ・ ・ Doorphone master unit 5 ・ ・ Video signal demodulation circuit 6 ・ ・ TV monitor 11 ・ ・ Doorphone slave unit 13 ・ ・ ・ ・ Video signal modulation Circuit 15 ··· Image sensor 16 ··· Image sensor control circuit 17 ··· Control speed changeover switch for flicker reduction (control speed changeover switch)

Claims (1)

[Scope of utility model registration request] 1. An image pickup device for picking up an image of a visitor illuminated by a fluorescent lamp, an image pickup device control circuit for controlling the image pickup device with an electronic shutter function, and a control speed of the electronic shutter function of the image pickup device control circuit. A control speed changeover switch for switching from a first control speed to a second control speed according to the light and shade of a visitor illuminated by a lamp, and a video signal modulation circuit for modulating a video signal generated according to the control speed. And a doorphone master unit that receives a video signal modulated by the video signal modulation circuit of the doorphone slave unit, and the doorphone master unit demodulates the received video signal. A television door intercom device comprising a circuit and a television monitor for monitoring the video signal demodulated by the video signal demodulation circuit.