JP2008011063A - Intercom system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intercom system for enhancing the visibility of an image displayed on a monitor by ensuring excellent image quality without causing deformation in the image when correction of a detected code error is disabled in the case that the code error such as a noise takes place in a video signal coded and transmitted from a slave unit to a master unit via a transmission path. <P>SOLUTION: In the case that the code error such as noise is produced in the video signal coded and transmitted from the first slave unit (slave unit) 1a to the first master unit (master unit) 2a via the transmission path L, the display of the image outputted to the monitor 204 when the correction of the detected code error is disabled is switched to re-display of a video signal of a frame having been outputted to the monitor before the detection of the code error or display of a prescribed video image. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an interphone device, and in particular, has a function of controlling image output on a monitor when a code error such as noise occurs in a video signal encoded and transmitted from a slave unit to a master unit via a transmission path. The present invention relates to an intercom device provided.

Conventionally, for example, when a video signal such as a moving image captured by a camera on the transmission side is output on a monitor on the reception side, encoding is performed on the transmission side while decoding is performed on the reception side. It has been known. As a device having this technique, data encoded using transform coding is suitable for the properties of transform coefficients and can be considered in terms of temporal correlation, and is read when the encoded image data is decoded. A moving image transform coding error correction apparatus capable of correcting an error in image data is disclosed (see, for example, Patent Document 1).
JP-A-5-161128 (paragraph numbers “0020” to “0113”, FIGS. 1 to 19)

  According to the moving image transform coding error correction apparatus disclosed in Patent Document 1 described in the background art, screen collapse due to an error occurring on a transmission line connecting the encoder and the decoder is minimized. Correct error correction. However, when an error in the error code cannot be corrected in the decoder, if an error occurs at the head of the display frame, the video after the error position is displayed in a largely corrupted state, and there is a problem in that visibility is lowered. .

  The present invention has been made to solve this problem, and when a code error such as noise occurs in a video signal encoded and transmitted from a slave unit to a master unit via a transmission path, An object of the present invention is to provide an interphone device that ensures visibility by ensuring a good image quality without image distortion when correction is impossible or when a code error is detected.

  In order to achieve the above-described object, an interphone device according to a first aspect of the present invention includes a slave unit having a camera and an image captured by the slave unit camera connected to the slave unit via a transmission path. And a master unit having a monitor for outputting a signal. The slave unit is provided with an error correction encoding circuit that adds a code for detecting and correcting a code error such as noise mixed in the video signal transmitted to the master unit via the transmission path. . The master unit detects a code error such as noise mixed in the video signal transmitted from the slave unit via the transmission line. If the code error cannot be corrected, the master unit displays the error on the monitor before detection. An error correction decoding circuit for redisplaying the video signal of the frame that has been displayed is provided.

The intercom apparatus according to the second aspect of the present invention is connected to a slave unit having a camera and a slave unit via a transmission path, and outputs a video signal captured by the slave unit camera. And a master unit having a monitor. The slave unit is provided with an error correction encoding circuit that adds a code for detecting and correcting a code error such as noise mixed in the video signal transmitted to the master unit via the transmission path. . The master unit detects a code error such as noise mixed in the video signal transmitted from the slave unit via the transmission line, and when it is impossible to correct the code error, the master unit outputs a predetermined image to the monitor. This is provided with an error correction decoding circuit for switching to video display.
Is.

  The intercom device according to the third aspect of the present invention is connected to a slave unit having a camera and a slave unit via a transmission line, and outputs a video signal captured by the slave unit camera. And a master unit having a monitor. The slave unit includes an error detection encoding circuit for detecting a code error such as noise mixed in the video signal transmitted to the master unit via the transmission path. The master unit detects a code error such as noise mixed in the video signal transmitted from the slave unit via the transmission line, and when the code error is detected, the master unit displays the image on the monitor before the detection. An error detection decoding circuit for redisplaying the video signal of the frame is provided.

  The intercom apparatus according to the fourth aspect of the present invention is connected to a slave unit having a camera and a slave unit via a transmission path, and outputs a video signal captured by the slave unit camera. And a master unit having a monitor. The slave unit includes an error detection encoding circuit for detecting a code error such as noise mixed in the video signal transmitted to the master unit via the transmission path. The master unit detects a code error such as noise mixed in the video signal transmitted from the slave unit via the transmission path, and when a code error is detected, the master unit displays the image on the monitor. An error detection decoding circuit for switching to display is provided.

  According to the intercom apparatus of the present invention, when a code error such as noise occurs in a video signal encoded and transmitted from the slave unit to the master unit via the transmission path, the detected code error cannot be corrected. In such a case, the image output to the monitor when the code error is detected is switched to the redisplay of the video signal of the frame that has been output to the monitor before the detection of the code error, or to the display of a predetermined image. Further, it is possible to ensure visibility with good image quality without image collapse and to improve visibility.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments to which an interphone device of the invention is applied will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a specific configuration of the intercom apparatus according to the first embodiment of the present invention. In this intercom device, for example, a slave unit (hereinafter referred to as a first slave unit) 1a installed outside a dwelling unit, for example, a entrance to the unit, and a master unit (hereinafter referred to as a first master unit) installed in the dwelling unit. .) 2a is provided, and the first slave unit 1a and the first master unit 2a are connected via a transmission line L1.

  The first handset 1a includes a call button 100, a microphone (hereinafter referred to as a handset microphone) 101, a speaker (hereinafter referred to as a handset speaker) 102, and an audio codec (hereinafter referred to as a handset voice codec). ) 103, camera 104, video encoder 105, frame assembling / disassembling circuit (hereinafter referred to as slave unit frame assembling / disassembling circuit) 106, error correction encoding circuit 107, transmission / reception circuit (hereinafter referred to as slave unit transmitting / receiving circuit) 108 , And a CPU (hereinafter referred to as a slave CPU) 109.

  In the first handset 1a, the call button 100 is operated by a person at the entrance of the dwelling unit, for example, a visitor, to call a resident in the dwelling unit.

  The handset microphone 101 and handset speaker 102 are used to input / output call voice (sending voice) for a visitor who has performed a call operation to establish a call with a resident. Reference numeral 103 denotes an analog / digital conversion of a speech voice (speech voice) input to the handset microphone 101 and sends the analog voice signal to the handset frame assembling / disassembling circuit 106, and the handset frame assembling / disassembling circuit 106. Is used for digital / analog conversion of a digital voice signal of a call voice (received voice) output from the handset speaker 102 transmitted via. In addition, the cordless handset microphone 101 can collect not only the above-described call function but also ambient sound for monitoring the appearance outside the dwelling unit (dwelling unit entrance), for example.

  The camera 104 is for capturing a video of a visitor who has performed a call operation and a video (surveillance video) in the vicinity of the outside of the dwelling unit (the entrance to the dwelling unit). The video encoder 105 is captured by the camera 104. The analog video signal of the video is converted from analog to digital and sent to the slave unit frame assembly / disassembly circuit 106. As the camera 104, various image pickup devices such as a CCD and a CMOS are suitable.

  The handset frame assembling / disassembling circuit 106 includes a call signal generated by the handset CPU 109 that detected the operation of the call button 100, a digital audio signal analog / digital converted via the handset voice codec 103, and a video encoder. The digital video signals that have been converted from analog to digital via 105 are each configured to be a predetermined frame that is transmitted on the transmission line L1, and are sent to the error correction coding circuit 107 and transmitted to and received from the slave unit. A response signal, an end signal, and a digital audio signal, which will be described later, transmitted through the circuit 108 are separated from each other. The response signal and the end signal are transmitted to the slave unit CPU 109, and the digital audio signal is transmitted to the sub unit. This is for transmission to the machine audio codec 103.

  The error correction coding circuit 107 adds a code for detecting and correcting a code error such as noise mixed in the digital video signal transmitted to the first base unit 2a via the transmission line L1. The slave transmission / reception circuit 108 is for forming a signal transmission line from the error correction coding circuit 107 to the transmission line L1, and a signal transmission line from the transmission line L1 to the slave unit frame assembly / disassembly circuit 106, respectively. It is.

  The slave CPU 109 detects the operation of the call button 100 and controls the camera 104 and the video encoder 105 to be active (beginning of operation), respectively, and receives a response signal transmitted from the first master 2a. Receiving and controlling the handset audio codec 103 to be active (beginning of operation), and further receiving the end signal transmitted from the first base unit 2a, This is for controlling the camera 104 and the video encoder 105 to be inactive (operation stop).

  Further, the first parent device 2a includes a microphone (hereinafter referred to as a parent device microphone) 200, a speaker (hereinafter referred to as a parent device speaker) 201, a voice codec (hereinafter referred to as a parent device voice codec) 202, a telephone call. Button 203, monitor 204, memory 205, video decoder 206, frame assembling / disassembling circuit (hereinafter referred to as “base unit frame assembling / disassembling circuit”) 207, error correction decoding circuit 208, transmission / reception circuit (hereinafter referred to as “parent unit transmission / reception circuit”) ) 209 and a CPU (hereinafter referred to as a parent device CPU) 210.

  In the first base unit 2a, the base unit microphone 200 and the base unit speaker 201 provide call voice (transmission voice) for a resident who has made a response operation described later to establish a call with a visitor. The base unit voice codec 202 performs analog / digital conversion on the analog voice signal of the call voice (transmitted voice) input to the base unit microphone 200 and sends it to the base unit frame assembly / disassembly circuit 207. At the same time, the digital voice signal of the call voice (received voice) output from the master speaker 201 transmitted via the master frame assembling / disassembling circuit 207 is converted from digital to analog. The main unit speaker 201 emits not only the above-mentioned call function, but also, for example, a content indicating that a visitor has called from the first sub unit 1a, a ringing sound of a predetermined pattern, a voice message, etc. Call notification can be made.

  The call button 203 is for a resident to perform a response operation or a call end operation when a call using the parent device microphone 200 and the parent device speaker 201 is established or the established call is terminated.

  The monitor 204 is used to display an image captured by the camera 104 of the first slave unit 1a or display a predetermined image, and the memory 205 includes a master unit frame assembly / disassembly circuit 207. A digital video signal transmitted via the storage is stored, for example, compressed and stored, and a predetermined video to be displayed on the monitor 204 is stored in advance. Further, the video decoder 206 performs digital / analog conversion on the digital video signal or predetermined video read from the memory 205, and monitors the video captured by the camera 104 of the first slave unit 1a or the predetermined video. It is for making it output to 204. Note that various displays such as an LCD and an organic EL display are suitable as the monitor 204, and various storage elements (storage media) such as a RAM and an EEPROM are suitable as the memory 205, for example.

  The base unit frame assembling / disassembling circuit 207 is generated by the base unit CPU 210 that detects a digital voice signal analog / digital converted via the base unit voice codec 202 and a response operation or call end operation of the call button 203. Each of the response signal and the end-call signal is configured to be a predetermined frame that is transmitted on the transmission line L 1, and is transmitted to the parent device transmission / reception circuit 209 and transmitted via the parent device transmission / reception circuit 209. The call signal, digital video signal, and digital audio signal having a predetermined frame structure are separated, and the call signal is sent to the master CPU 210, the digital video signal is sent to the memory 205, and the digital voice signal is sent to the master audio codec 202. Is for.

  The error correction decoding circuit 208 detects a code error such as noise mixed in the digital video signal transmitted from the first slave unit 1a via the transmission line L1, and corrects the detected code error. If this is possible, the code error is corrected. If correction is impossible, a signal to that effect is generated and sent to the master CPU 210. The signal transmission line from the base frame assembly / disassembly circuit 207 to the transmission line L1 and the signal transmission line from the transmission line L1 to the error correction decoding circuit 208 are formed.

  The base unit CPU 210 receives the call signal from the first handset 1a, controls the monitor 204 and the video decoder 206 to be active (starts operation), and detects the response operation of the call button 203. Thus, the master audio codec 202 is controlled to be active (operation start), and the call end operation of the call button 203 is detected, so that the master audio codec 202, the monitor 204, and the video decoder 206 are inactive. It is for controlling to be active (operation stop). The master CPU 210 controls the memory 205 or the video decoder 206 to detect an output signal from the error correction decoding circuit 208 and switch the output on the monitor 204 to a predetermined image. It is.

  In the intercom apparatus according to the first embodiment of the present invention configured as described above, a specific operation will be described below.

  In FIG. 1, when a person at the entrance of the dwelling unit, for example, a visitor, calls the resident in the room in the dwelling unit and operates the call button 100 of the first handset 1a, the child who has detected this call operation is detected. The machine CPU 109 generates a calling signal S1, and controls the camera 104 and the video encoder 105 to be active. A visitor's image captured by the camera 104 and an image in the vicinity of the entrance of the dwelling unit (monitoring image) are analog / digital converted into a digital image signal S2 via the image encoder 105, and then the child device frame. It is sent to the assembly / disassembly circuit 106.

  The handset frame assembling / disassembling circuit 106 of the first handset 1a is a predetermined frame for transmitting the calling signal S1 from the handset CPU 109 and the digital video signal S2 from the video encoder 105 on the transmission line L1. To generate an upstream signal (hereinafter referred to as an upstream signal when calling) S3. This call-up uplink signal S3 is encoded into the call-up uplink encoded signal S4 via the error correction encoding circuit 107, and then the slave unit transmission / reception circuit 108, the transmission line L1, and the parent of the first master unit 2a. The data is transmitted to the error correction decoding circuit 208 via the machine transmission / reception circuit 209. Further, the error correction decoding circuit 208 decodes the received call-up uplink signal S4 into the call-up uplink signal S3, and then sends it to the master frame assembling / disassembly circuit 207.

  The base frame assembly / disassembly circuit 207 of the first base unit 2a uses the call up signal S3 assembled into a predetermined frame decoded via the error correction decoding circuit 208 as the call signal S1. Separated into the digital video signal S 2, the calling signal S 1 is sent to the master CPU 210, and the digital video signal S 2 is sent to the memory 205.

  In the above description, the call signal S1 generated by the slave CPU 109 of the first slave 1a and the digital video signal S2 analog / digital converted via the video encoder 105 are transmitted on the transmission path. In assembling a predetermined frame to be transmitted on the L1 line, the call upstream signal S3, which is the same upstream signal, is generated by the handset frame assembly / disassembly circuit 106. However, the present invention is not limited to this mode. For example, an upstream signal can be generated by assembling a predetermined frame for transmission on the transmission line L1 for each of the call signal S1 and the digital video signal S2.

  The master CPU 210 of the first master unit 2a receives a call from the first slave unit 1a by a visitor based on the call signal S1 separated via the master unit frame assembly / disassembly circuit 207. Is detected, and a ringing tone or voice message of a predetermined pattern is emitted from the main unit speaker 201 to notify the calling, and the monitor 204 and the video decoder 206 are controlled to be active (operation start), respectively. . The master CPU 210 can also display on the monitor 204 a text message or picture data indicating that there is a call from the first slave 1a by a visitor.

  The memory 205 of the first base unit 2a stores the digital video signal S2 separated via the base unit frame assembling / disassembling circuit 207, for example, by compressing and storing the digital video signal S2 as a video decoder. The analog video signal digital / analog converted via the video decoder 206, that is, the video of the visitor imaged by the camera 104 of the first slave unit 1a and the vicinity of the dwelling entrance Video (monitoring video) starts to be displayed on the monitor 204 for each frame.

  Next, there is a call from a visitor based on a video output on the monitor 204, such as a ringing sound of a predetermined pattern and a voice message emitted from the parent speaker 201 of the first parent device 2a. When the resident who has confirmed this in conjunction with the identification of the visitor operates the call button 203, a response signal S5 is generated in the master CPU 210 that detects this response operation, and the master audio codec 202 is activated. It is controlled so as to become (operation start).

  The base unit frame assembly / disassembly circuit 207 of the first base unit 2a assembles the response signal S5 generated by the base unit CPU 210 into a predetermined frame that is transmitted on the line of the transmission line L1, and transmits a downstream signal (hereinafter, referred to as a downstream signal). This is referred to as a response down signal.) S6 is generated. This response down signal S6 is transmitted from the master unit frame assembly / disassembly circuit 207 via the master unit transmission / reception circuit 209, the transmission line L1, and the slave unit transmission / reception circuit 108 of the first slave unit 1a. 106. The slave unit frame assembling / disassembling circuit 106 separates the response signal S5 from the received response down signal S6 (or its frame) and sends it to the slave unit CPU 109.

  The handset CPU 109 of the first handset 1a detects that a response operation has been performed by the resident based on the response signal S5 separated via the handset frame assembly / disassembly circuit 106, Control is performed so that the handset audio codec 103 becomes active (starts operation). By this control, the handset microphone 101 to the handset used by the visitor, the handset voice codec 103, the handset frame assembling / disassembling circuit 106, the error correction coding circuit 107, the handset transmitting / receiving circuit 108, the transmission path L1, the first parent A call line (hereinafter referred to as a parent line speaker 201) used by a resident via the parent machine transmission / reception circuit 209, error correction decoding circuit 208, parent machine frame assembly / disassembly circuit 207, and parent machine voice codec 202 of the machine 2a. An upstream call line) from the master microphone 200 used by the resident to the master voice codec 202, the master frame assembling / disassembling circuit 207, the master transceiver circuit 209, the transmission line L1, and the first slave 1a. Via handset transceiver circuit 108, handset frame assembling / disassembling circuit 106, handset voice codec 103 to handset speaker 102 used by the visitor Call lines (hereinafter, referred to downlink speech line.) Are formed, respectively.

  Next, in the case where the above-described uplink call line and downlink call line are respectively formed, the resident inputs to the master microphone 200 of the first master unit 2a when establishing a call with the visitor. The call voice (transmitted voice) is converted into a digital voice signal (hereinafter referred to as a downstream digital voice signal) S7 via the master voice codec 202, and then converted into a master frame assembling / disassembling circuit 207. Sent out.

  The base unit frame assembly / disassembly circuit 207 of the first base unit 2a assembles the downstream digital audio signal S7 from the base unit audio codec 202 into a predetermined frame for transmission on the line of the transmission line L1, and transmits the downstream signal (hereinafter referred to as the downstream signal). This is referred to as a down signal during a call.) S8 is generated. This call down signal S8 is transmitted to the handset frame assembly / disassembly circuit 106 of the first handset 1a through the same signal transmission line as the response down signal S6.

  The handset frame assembling / disassembling circuit 106 of the first handset 1a separates the downstream digital audio signal S7 from the received downlink signal S8 (frame thereof) and sends it to the handset audio codec 103. Further, the slave unit audio codec 103 performs a response operation by converting the downstream digital audio signal S7 separated via the slave unit frame assembling / disassembling circuit 106 from digital to analog and sending it to the slave unit speaker 102. In addition, the call voice (received voice) of the resident can be output from the handset speaker 102.

  On the other hand, when a visitor establishes a call with a resident, the call voice (transmitted voice) input to the handset microphone 101 of the first handset 1 a is digitally transmitted via the handset voice codec 103. An audio signal (hereinafter, referred to as an upstream digital audio signal) is analog / digital converted to S9 and then sent to the handset frame assembling / disassembling circuit 106.

  The handset frame assembling / disassembling circuit 106 of the first handset 1a is connected to the digital audio signal S9 from the handset audio codec 103 and the digital video from the video encoder 105 continuously transmitted from the time of the calling operation. The signal S2 is assembled into a predetermined frame to be transmitted on the transmission line L1, and an uplink signal (hereinafter referred to as an uplink signal during communication) S10 is generated. The call uplink signal S10 is encoded into the call uplink encoded signal S11 via the error correction coding circuit 107, and then transmitted through the same signal transmission line as the call uplink signal S4. To the error correction decoding circuit 208 of the first base unit 2a. Further, the error correction decoding circuit 208 decodes the received uplink encoded signal S11 during the call into the uplink signal S10 during the call, and then sends it to the base frame assembling / disassembling circuit 207 and also adds noise to the digital video signal S2. If the detected code error can be corrected, the code error is corrected. If the error cannot be corrected, the fact is corrected. A signal S12 is generated and sent to the master CPU 210.

  The master frame assembling / disassembling circuit 207 of the first master unit 2a converts the upstream signal S10 during a call, which is assembled into a predetermined frame decoded via the error correction decoding circuit 208, into an upstream digital audio signal. S9 and digital video signal S2 are separated, and upstream digital audio signal S9 is sent to base unit audio codec 202, and digital video signal S2 is sent to memory 205.

  The base unit audio codec 103 of the first base unit 2a converts the upstream digital audio signal S9 separated via the base unit frame assembling / disassembling circuit 207 from digital to analog and sends it to the base unit speaker 201. The call voice (received voice) of the visitor who has performed the calling operation can be output from the main unit speaker 201.

  Next, in the case where the above-described call is established, when the code error such as noise detected by the error correction decoding circuit 208 of the first master unit 2a can be corrected, the monitor 204 is The output operation and the output operation to the monitor 204 when the same correction is impossible will be described separately.

  When the code error detected by the error correction decoding circuit 208 of the first master unit 2a can be corrected, the memory 205 stores a digital video signal separated via the master frame assembly / disassembly circuit 207. S2 is stored, for example, compressed and stored, and this digital video signal S2 is sent to the video decoder 206, whereby an analog video signal digital / analog converted via the video decoder 206, that is, the first video signal Visitors' images captured by the camera 104 of the slave unit 1a and images around the entrance of the dwelling unit (monitoring images) are continuously displayed on the monitor 204 for each frame even during a call.

  On the other hand, when it is impossible to correct the code error detected by the error correction decoding circuit 208 of the first base unit 2a, the memory 205 is digital as in the case where the detected code error can be corrected. Although the video signal S2 is compressed and stored, the output to the monitor 204 is output before the detection of the code error under the control of the master CPU 210 that has detected the output signal S12 from the error correction decoding circuit 208. Redisplay the video signal of the frame, display a predetermined video stored in the memory 205 in advance, for example, a message image such as “Please wait for a while because the image is distorted”, or the video decoder 206 Since the display is switched to one of the predetermined images to be generated, for example, a single color display such as blue, good image quality without image distortion is ensured and visibility is high. It is.

  Next, in order for the resident to terminate the call established with the visitor, if the call button 203 of the second master unit 2a is operated (again), the master unit CPU 210 that has detected this end-call operation is notified. Thus, the end signal S13 is generated, and the master audio codec 202, the monitor 204, and the video decoder 206 are controlled to be inactive (stop operation).

  The base unit frame assembly / disassembly circuit 207 of the first base unit 2a assembles the end signal S13 generated by the base unit CPU 210 into a predetermined frame to be transmitted on the line of the transmission line L1, and transmits a downstream signal (hereinafter referred to as a downstream signal). This is referred to as a down signal at the end of call.) S14 is generated. This downstream signal S14 is transmitted to the handset frame assembling / disassembling circuit 106 of the first handset 1a through the same signal transmission line as the response down signal S6 and the talking down signal S8. The In addition, handset frame assembling / disassembling circuit 106 separates end-call signal S13 from the received end-call down signal S14 (frame thereof) and sends it to handset CPU 109.

  The handset CPU 109 of the first handset 1a detects that the resident has performed a call end operation based on the call end signal S13 separated via the handset frame assembly / disassembly circuit 106. Thus, the slave audio codec 103, the camera 104, and the video encoder 105 are controlled so as to be inactive (operation stopped). By the control up to this point, the first slave unit 1a and the first master unit 2a are respectively shifted (recovered) to the standby state.

  As is apparent from the above description, according to the intercom apparatus according to the first embodiment of the present invention, it is encoded and transmitted from the first slave unit 1a to the second master unit 2a via the transmission line L1. When a code error such as noise occurs in a video signal (digital video signal) to be detected, an image output to the monitor 204 when the detected code error cannot be corrected is displayed on the monitor 204 before the code error is detected. By switching to redisplay of the video signal of the frame that has been displayed or displaying a predetermined video, it is possible to ensure good image quality without image corruption and to improve visibility.

  According to the intercom apparatus of the first embodiment of the present invention, the video signal (digital video signal) encoded and transmitted from the first slave unit 1a to the first master unit 2a via the transmission line L1. When a code error such as noise occurs in the monitor 204, it is impossible to correct the detected code error in order to improve the visibility by ensuring the image output to the monitor 204 with good image quality without image corruption. The control of the master CPU 210 that has detected the output signal S12 from the error correction decoding circuit 208 that has detected is applied, but the present invention is not limited to this control means.

  For example, as shown in the block diagram of FIG. 2, the intercom apparatus according to the second embodiment of the present invention is encoded and transmitted from the second slave unit 1b to the second master unit 2b via the transmission line L1. The second slave unit is provided with an error detection encoding circuit 110 for providing a code for detecting a code error such as noise mixed in a video signal (digital video signal), and further via a transmission line L1. If a code error such as noise mixed in the video signal (digital video signal) encoded and transmitted from the second slave unit 1b is detected, and if a code error is detected, a signal S15 indicating that is sent. By providing the second master unit with an error detection decoding circuit 211 that generates and sends it to the master CPU 210, the output to the monitor 204 when a code error is detected is displayed in the first embodiment. As in By switching to display of a video signal of a frame that was previously displayed on the monitor 204 or displaying a predetermined video, it is possible to secure a good image quality without image distortion and improve visibility.

  Further, according to the intercom apparatus according to the first and second embodiments of the present invention, the connection between the first slave unit 1a and the first master unit 2a, the second slave unit 1b, and the second master unit 2b. However, the present invention is not limited to this mode and can be configured by wireless connection.

  The intercom apparatus of the present invention has been described with a specific embodiment, but the present invention is not limited to this form, and any interphone apparatus of any configuration known so far can be used as long as the effects of the present invention are achieved. It goes without saying that can also be adopted.

The block diagram which shows the specific structure of the intercom apparatus by 1st Example of this invention. The block diagram which shows the specific structure of the intercom apparatus by 2nd Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a ... 1st subunit | mobile_unit 104 ... Camera 107 ... Error correction encoding circuit 1b ... 2nd subunit | mobile_unit 104 ... Camera 110 ... Error detection encoding circuit 2a ... 1st main | base station 204 ... ... monitor 208 ... error correction decoding circuit 2b ... second master unit 204 ... monitor 211 ... error detection decoding circuit L1 ... transmission line

Claims (4)

A slave (1a) having a camera (104) and a monitor (204) connected to the slave via a transmission path (L1) and outputting a video signal captured by the camera of the slave ) And a master unit (2a) having
The slave unit includes an error correction encoding circuit (107) that provides a code for detecting and correcting a code error such as noise mixed in the video signal transmitted to the master unit via the transmission path. )
The master unit detects a code error such as noise mixed in the video signal transmitted from the slave unit via the transmission path, and the detection is performed when the code error cannot be corrected. An intercom apparatus comprising an error correction decoding circuit (208) for re-displaying a video signal of a frame previously displayed on the monitor. A slave (1a) having a camera (104) and a monitor (204) connected to the slave via a transmission path (L1) and outputting a video signal captured by the camera of the slave ) And a master unit (2a) having
The slave unit includes an error correction encoding circuit (107) that provides a code for detecting and correcting a code error such as noise mixed in the video signal transmitted to the master unit via the transmission path. )
The master unit detects a code error such as noise mixed in the video signal transmitted from the slave unit via the transmission path, and the monitor error is detected when the code error cannot be corrected. An intercom apparatus comprising an error correction decoding circuit (208) for switching an image output to a predetermined video display. A slave unit (1b) having a camera (104) and a monitor (204) connected to the slave unit via a transmission path (L1) and outputting a video signal imaged by the camera of the slave unit ) And a master unit (2b) having
The slave unit includes an error detection encoding circuit (110) for detecting a code error such as noise mixed in the video signal transmitted to the master unit via the transmission path,
The master unit detects a code error such as noise mixed in the video signal transmitted from the slave unit via the transmission line, and detects the code error before detecting the code error. An intercom apparatus comprising an error detection decoding circuit (211) for redisplaying a video signal of a frame that has been displayed on a monitor. A slave unit (1b) having a camera (104) and a monitor (204) connected to the slave unit via a transmission path (L1) and outputting a video signal imaged by the camera of the slave unit ) And a master unit (2b) having
The slave unit includes an error detection encoding circuit (110) for detecting a code error such as noise mixed in the video signal transmitted to the master unit via the transmission path,
The master unit detects a code error such as noise mixed in the video signal transmitted from the slave unit via the transmission path, and outputs the signal to the monitor when the code error is detected. An intercom apparatus comprising an error detection decoding circuit (211) for switching a picture to a predetermined video display.

Images