JP2536688B2 - TV intercom - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a television interphone capable of capturing a visitor's face or the like with a television camera at a front entrance, a gate, or the like of a general household or the like and monitoring the interior of the house. It is about.

[Prior Art] This type of TV intercom can be
It consists of a slave unit with a built-in TV camera installed at the gate, etc. and a master unit installed in the house with a built-in monitor. A visitor standing in front of the entrance is imaged by the TV camera and the video signal is used as a master unit. The family members check the visitors by sending them and monitoring them.

In such a TV intercom, a mechanism-type viewing angle adjustment function is added in order to capture an image of a visitor standing in front of the front door on the monitor, but once the field of view is fixed, it remains constant. In order to capture the image in the field of view, when the position where the visitor stands and the height change, the image of the visitor cannot be captured accurately.

In order to improve the above-mentioned drawbacks, the direction of the television camera in the slave unit is mechanically changed under the control of the master unit to obtain a desired field of view. There is also a thing to set widely.

[Problems to be Solved by the Invention]

However, in the former one, it is necessary to mechanically change the angle of the TV camera in two horizontal and vertical directions,
There are disadvantages in that a complicated mechanism and a drive unit are required, which leads to an increase in cost, a possibility of failure, and a shortened life. In addition, the latter one has a drawback that the monitor screen of the parent device is small, so that a visitor is displayed in a small size in a part of the screen and is difficult to see.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a television intercom that can monitor a visitor with a simple configuration and reliably and easily.

[Means for solving the problem]

A television intercom according to the present invention includes an image pickup unit for picking up an image of a visitor or the like, a slave unit having a video output circuit for outputting a video signal from the image pickup unit to a transmission line, and a video signal transmitted via the transmission line. A / D conversion means for digitizing, A / D conversion control means for outputting sampling pulses to the A / D conversion means, and an image memory for storing image data output from the A / D conversion means according to the sampling pulses The read control means for outputting a control signal of the read timing of the image data stored in the image memory, and the image data read by the read control means are D / A.
A parent having a D / A converting means for converting, a monitor for displaying an analog image signal output from the D / A converting means on a screen, and a cursor display control means for controlling the position and size of a cursor displayed on the monitor. The cursor display control means to display a cursor of a predetermined size at a desired position on the monitor, and based on a control signal from the cursor display control means, sampling from the A / D conversion means. Of the area imaged by the imaging means by the pulse, only a predetermined area is written in the image memory, and the image signal stored in the image memory is read by the reading control means at a timing different from that at the time of writing, It is characterized in that only a predetermined area is enlarged and displayed on the monitor.

[Action]

In the television intercom of the present invention, a cursor of a predetermined size is displayed by the cursor display control means in the vicinity of the face of the visitor displayed on the screen, and based on the control signal from the cursor display control means, A / D By the sampling signal from the conversion control means, of the entire area to be imaged,
Only a predetermined area is written in the image memory, and the image signal stored in the image memory is read at a timing different from that at the time of writing by the read control signal from the read control means, and only the predetermined area is enlarged and displayed on the monitor. is there.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of the present invention. 1
Is a child device installed at the entrance, gate, etc. of a general household, which images a visitor and outputs a video signal thereof. The slave unit 1 includes an image pickup unit 11 for picking up an image of a visitor, and a video output circuit 12 for transmitting a video signal output from the image pickup unit 11 from the slave unit 1 to a master unit 2 described later. Video output circuit
Reference numeral 12 includes a balancing circuit when the video signal and the power supply are superimposed by using a simple pair line such as a transmission line as the transmission line. The image pickup means 11 is a CC from the viewpoint of cost and stability.
It is preferable to use the D image pickup device, and it is preferable to set the wide angle so that the visitor stands in front of the child device 1 and absorbs variations in height and the like.

Reference numeral 3 denotes a transmission line composed of a coaxial cable or a telephone line, and transmits a video signal output from the slave 1 to the master 2.

Reference numeral 2 denotes a master unit installed in the house, which captures a video signal input from the slave unit 1 via the transmission line 3 and monitors an image. The master device 2 is an A / D conversion means 2
1, an image memory 22, a D / A conversion means 23, a monitor 24, an A / D conversion control means 25, a read control means 26 and a cursor display control means 27. The video signal from slave unit 1 is A / D
It is input to the conversion means 21 and converted into, for example, 8-bit digital image data per pixel according to the sampling signal from the A / D conversion control means 25. This digital image data is once stored in the image memory 22. The memory size of the image memory 22 is, for example, 512 × 512 or 256 × 256. The digital image data stored in the image memory 22 is
It is read by a read signal from the read control means 26, converted into a video signal as an analog signal by the D / A conversion means 23, and displayed on the monitor 24.

The A / D conversion control means 25 generates a sampling pulse for digital conversion only during the period of the sampling region in the video signal. Here, the sampling area 5 is the second
As shown in FIG. 6A, it is a partial area in the image pickup area 4 which is held in the temporary image memory 22 for enlarged display, and has the same aspect as the image pickup area 4 displayed on the monitor 24. It is a region having a rectangular shape with a ratio. The sampling area 5 is set by the cursor display control means 27 by bringing a cursor of a predetermined size to a predetermined position. Sampling area 5
As shown in FIG. 3 (a), the writing of the image signal into the image memory 22 is based on a control signal from the cursor display control means 27, and the synchronizing signal of the video signal 6 is generated only for a predetermined period 8 in the vertical period. Sampling area 5 during horizontal period 7 between 10
Is performed by generating the sampling pulse 9 in the period 8 corresponding to. The sampling pulse generated from the A / D conversion control means 25 is used as a sampling signal in the A / D conversion means 21 and is used as a write signal in the image memory 22. Therefore, the number of sampling pulses and the size of the image memory 22 may be the same, for example, both may be 256 × 256. With such a configuration, the image memory 22 does not need to store the entire imaging field of view, and it is sufficient to prepare a memory for only the sampling region, so that the memory capacity can be saved.

The read control means 26 outputs a control signal for reading the digital image data of the sampling area 5 stored in the image memory 22 in the next frame. At this time, in order to perform enlarged display, reading is performed at a timing different from that at the time of writing. The image data corresponding to the period 8 corresponding to the sampling region 5 in the horizontal period 7 of the video signal 6 is read out as the data of the entire horizontal period 7 as shown in FIG. 3 (b). That is, in the horizontal direction, 256 read signals are evenly distributed over the entire horizontal period 7.

Normally, a general video signal has 525 scanning lines, the image memory 22 has a vertical size of 256 lines, and since it is only half of the scanning lines, one screen is formed by reading the same content twice. To do. That is, in the vertical direction, if the same content is displayed over two interlaced fields, the same data will be arranged in two lines.
As shown in FIG. 6B, the entire screen is enlarged and displayed.

Next, an actual operation procedure will be shown. When a visitor appears,
The monitor 24 displays the entire wide-angle field of view as shown in FIG. The householder displays a cursor K having an area of a predetermined size as shown in FIG. 4 (b) on the screen of the monitor 24 and moves the cursor K displayed by the key operation to obtain a desired area K '. To the position of. In this state, if an enlargement is instructed, the area K'is enlarged and displayed on the entire screen as shown in FIG. 4 (c).

In the above embodiment, the case where the number of the image memory 22 is one has been described. However, in this way, the frames input to the image memory 22 and the frames for displaying the contents are alternately displayed, and the screen is displayed. Although it flickers a little, there is no problem if it is used for a TV intercom. If you want to eliminate this phenomenon, prepare two image memories 22 and
It is possible to display a complete moving image by alternately switching and repeating input and enlarged display.

〔The invention's effect〕

As described above, according to the television interphone of the present invention, the cursor display control means causes the cursor of a predetermined size to be displayed near the face of the visitor displayed on the screen, and the control signal from the cursor display control means is displayed. Based on the sampling signal from the A / D conversion control means, only a predetermined area of the entire imaged area is written in the image memory, and the image signal stored in the image memory is read out by the read control means. Since a signal is read at a timing different from that at the time of writing and only a predetermined area is enlarged and displayed on the monitor, a television intercom that has a simple structure and can be surely seen by a visitor and can be easily viewed can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a schematic diagram showing a monitor according to the above, FIG. 3 is a waveform diagram for explaining the operation of the above, FIG. FIG. 3 is a schematic diagram showing a monitor for explaining the above operation. 1 ... Slave device, 2 ... Parent device 3 ... Transmission line, 4 ... Imaging area 5 ... Sampling area, 11 ... Imaging means 12 ... Video output circuit, 21 ... A / D conversion means 22 ... … Image memory, 23 …… D / A conversion means 24 …… Monitor 25 …… A / D conversion control means 26 …… Readout control means 27 …… Cursor display control means

Claims (1)

(57) [Claims] 1. An image pickup device for picking up an image of a visitor or the like, a slave unit having a video output circuit for outputting a video signal from the image pickup device to a transmission line, and a video signal transmitted through the transmission line is digitized. A / D conversion means and an A / D conversion control means for outputting a sampling pulse to the A / D conversion means, an image memory for storing image data output from the A / D conversion means according to the sampling pulse, and the image The read control means for outputting a control signal of the read timing of the image data stored in the memory, the D / A conversion means for D / A converting the image data read by the read control means, and the D / A converted It comprises a monitor for displaying an analog image signal on the screen and a master unit having cursor display control means for controlling the position and size of the cursor displayed on the monitor. Predetermined size of the cursor is displayed at a desired position of the monitor by means, on the basis of a control signal from the cursor display control means, said
By the sampling pulse from the A / D conversion control means, only a predetermined area of the area imaged by the imaging means is written in the image memory, and the image signal stored in the image memory is written by the read control means. A TV intercom that is characterized by reading out at a different timing than time and enlarging and displaying only a specified area on the monitor.