JP2011017860A - Video display device and method for switching displayed video - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify configuration for selecting and outputting a signal to be displayed among a plurality of input video signals.SOLUTION: A projector for displaying a video in a plurality of display areas includes: an input part 9 for inputting video signals via input ports, a receiver 10 for selecting and outputting video signals among the plurality of video signals input by the input unit 9, the selected video signals being as many as the number of displayed areas, and a video signal processing circuit 11 having a multiplexer for allocating the video signals output by the receiver 10 to the display areas. The receiver 10 includes switches 21 and 22, each of which selects and outputs one of the plurality of video signals based on a switching signal 201.

Description

  The present invention relates to a video display device that displays a plurality of videos and a display video switching method, and more particularly to a video display device that displays a plurality of videos simultaneously on the same screen and a display video switching method.

  In the case where a digital video signal to be transmitted is received, and the received video signal is processed and displayed, HDMI (High Definition Multimedia Interface) has recently been applied to the transmission path of the video signal. HDMI is characterized in that it mutually authenticates a communication partner and encrypts and transmits a high-quality video by a digital signal. Devices that supply signals according to HDMI (referred to as source devices) include DVD (Digital Versatile Disc) playback devices, Blue-Ray disc playback devices, and the like, which receive signals from source devices due to diversification of the types of source devices. The number of input ports in the main body of a device such as a video display device (referred to as a sink device) tends to increase. The sink device may have a port for inputting an analog video signal in addition to an input port for a digital video signal, and the number of input ports further increases.

  As a device including a plurality of input ports, there is a video display device such as a television receiver disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2009-21925). The apparatus includes a plurality of HDMI input ports for connecting a plurality of HDMI cables.

JP 2009-21925 A

  For example, a projector is assumed as the sink device. Assume that a projector having four HDMI input ports displays a video by a two-screen display function for simultaneously displaying two videos. Here, the two screens are screens for displaying one of the two videos, a relatively large screen (hereinafter referred to as a main screen), and a screen for displaying the other of the two videos. It is assumed that the screen is smaller than the main screen (hereinafter referred to as a sub screen).

  Here, when it is assumed that the projector switches the video to be displayed on each of the main screen and the sub screen according to the combination of the video signals of the four HDMI input ports, the HDMI for all the HDMI input ports. It is necessary to provide a receiver circuit, and a circuit constituting the projector becomes very expensive.

  FIG. 7 shows an example of a conventional configuration for solving the above-described cost problem. In FIG. 7, signals received at four HDMI input ports are given to receivers 103 and 104 via switch circuits 101 and 102. The receivers 103 and 104 receive and process received signals, and output the processed signals to the video signal processing circuit 105 for display. The switch 101 or 102 has a function of switching an input signal and a function of equalizing TMDS (Transition Minimized Differential Signaling). The receivers 103 and 104 have an HDCP (High-bandwidth Digital Content Protection System) key, an HDCP circuit having an authentication and decryption function, or a TMDS signal for driving a liquid crystal device. It has a circuit for converting to LVTTL (Low Voltage Transistor Transistor Logic) and outputting the converted signal. The video signal processing circuit 5 includes a circuit for generating two screens, and this circuit outputs two input video signals to a main window corresponding to the main screen and a sub window corresponding to the sub screen as shown in FIG. Each has a function of generating a video signal to be displayed.

  In the case of the circuit configuration of FIG. 7, the video signal input to the first to third ports among the four input ports of HDMI is given to the switch 101. The switch 101 selects one of the input video signals and outputs the selected video signal to the receiver 103. The video signal input to the fourth port of the HDMI input passes through the switch 102 and is output to the receiver 104. If the first to third ports of the HDMI input are assigned to the main window in FIG. 8 and the fourth port of the HDMI input is assigned to the sub-window, the main window is assigned to any one of the first to third ports of the HDMI input. The input video signal can be displayed, and the video signal input to the fourth port of the HDMI input can be displayed in the subwindow.

  At this time, when the video signal of the first port of HDMI input is displayed on the main window, the input video signal of the second port or the third port cannot be displayed on the sub window.

  When the signals input to the projector are a digital video signal and an analog video signal, the configuration of FIG. 7 is changed as shown in FIG. 9 includes an analog input (video or computer signal) port for inputting an analog video signal and an A / D (Analog / Digital) converter 106 in addition to the configuration of FIG. An input video signal from the analog input port is converted from an analog signal to a digital signal by the A / D converter 106 and then supplied to the video signal processing circuit 105.

  In operation, the video signal from the analog input port and the video signals output from the receivers 103 and 104 are supplied to the video signal processing circuit 105. The video signal processing circuit 105 internally switches input signals and outputs one of the input video signals. Therefore, the video signal to be displayed in the main window and the sub window can be exchanged between the analog signal and the digital signal.

  Next, in the configuration of FIG. 9, the input video signal of the analog input port is displayed in the main window, the input video signal is in the first port of the HDMI input, and the second port of the HDMI input is Assume that no video signal is input to the third port. The receivers 103 and 104 receive an encrypted video signal after performing authentication processing according to HDCP using a circuit for HDCP. The received video signal is decoded using a key according to the HDCP procedure, and the decoded video signal is output to the image signal processing circuit 105. At this time, the authentication process takes time (several seconds), and as a result, it takes time to display the video. The waiting time is troublesome for the user.

  This waiting time is due to the fact that the user cannot know the authenticated port. In other words, when the user switches the display of the video signal, while the video signal from the analog input port is displayed in one window, the video signal given to one of the HDMI input ports is displayed in the other window. Yes, but the user was not presented as to which port was authenticated. Therefore, there is a possibility of selecting an unauthenticated port. In this case, since it takes an authentication time, it takes time to display an image.

  Therefore, an object of the present invention relates to a video display device and a display video switching method in which a configuration for selecting and outputting a signal to be displayed among a plurality of input video signals is simplified.

  According to an aspect of the present invention, an image display device that displays an image in each of N (N is an integer of 2 or more) display areas includes M (M is an integer of 2 or more) input ports and is supplied from the outside. An input unit that inputs a video signal to be transmitted via each of the input ports, a receiving unit that selects and outputs N video signals from among the M video signals input by the input unit, and a receiving unit An allocation unit that allocates the display destination of each of the N video signals output by N to each of the N display areas. The receiving unit includes N selection units, and each of the selection units selects and outputs one video signal from among the M video signals based on a first signal given from the outside.

  Preferably, the allocating unit allocates the display destination of each of the N video signals to each of the N display areas based on the second signal given from the outside.

  Preferably, the M input ports include a first input port. The first input port starts an authentication process of the video display device in response to the authentication request, and displays the video when the authentication is successful. A signal supply device that starts supplying a video signal is connected to the device. The accepting unit includes an authentication unit that detects a result of the authentication process performed by the signal supply device connected to the first input port. The contents detected by the authentication unit are output.

Preferably, the detected content includes identification information of the first input port.
Preferably, the detection content is displayed simultaneously with the display of the video in the N display areas.

  Preferably, the authentication unit transmits an authentication request to the signal supply device via the first input port for authentication processing prior to reception of the video signal via the first input port. When the first signal or the second signal instructing to receive the video signal is given from the first input port to which the signal supply device that has succeeded in the authentication is connected, the authentication unit transmits an authentication request. Omitted.

  Preferably, the M input ports include an input port to which an analog video signal is supplied and an input port to which a digital video signal is supplied, and the first input port includes a port to which a digital video signal is input. Point to.

  According to another aspect of the present invention, a display image switching method in N (N is an integer of 2 or more) display areas where images are simultaneously displayed is externally connected to M (M is an integer of 2 or more) input ports. A step of inputting a video signal supplied from the step, a step of selecting and outputting N video signals from the input M video signals, and a step of selecting and outputting each of the N video signals selected and output Assigning a display destination to each of the N display areas.

  The step of selecting and outputting includes N selection steps. In each of the N selection steps, one video signal is selected from the M video signals based on the given first signal and output.

  According to the present invention, N video signals are selected from the input M video signals, and the display destinations of the selected N video signals are assigned to the N display areas, respectively. In this case, each of the N selection units (selection steps) selects and outputs one video signal from among the M video signals based on the first signal given from the outside.

  Thus, with a simple configuration in which N selection units (selection steps) are provided, the video signals that can be switched and displayed in each of the N display areas can be all of a plurality of input video signals.

  According to another aspect, since the identification information of the input port connected to the signal supply device that has been successfully authenticated is output, the user confirms the output content and the input that has been successfully authenticated. A first signal or a second signal instructing to selectively display a video signal from the port can be input. As a result, it is possible to quickly switch the video signal to be displayed without processing time for authentication.

It is a figure explaining the structure of the peripheral device at the time of projecting an image | video with the projector which concerns on this Embodiment. It is a figure which shows the structure of the projector which concerns on this Embodiment. It is a figure which shows the partial structure of FIG. 2 in detail. It is a block diagram of the video signal processing circuit which concerns on this Embodiment. It is a figure explaining an example of the image | video displayed (projection) which concerns on this Embodiment. It is a figure which shows an example of the process sequence which concerns on this Embodiment. It is the schematic which shows an example of a partial structure of the circuit of the conventional video display apparatus. It is a figure explaining allocation of the video which should be displayed on the conventional display screen. It is the schematic which shows the other example of a partial structure of the circuit of the conventional video display apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  With reference to FIG. 1, a configuration of a peripheral device when a video is projected by a projector 1 corresponding to the video display device according to the present embodiment will be described. A projector (hereinafter abbreviated as PJ) 1 is a liquid crystal projector that projects an image using a liquid crystal device, and projects (displays) an image by projecting light of the image displayed by the liquid crystal device onto a screen 6. ) The projection surface is not limited to the screen 6 and may be a wall surface. The PJ 1 includes a remote control receiving unit 20 that receives an infrared-modulated remote control signal transmitted from a remote control (abbreviated as a remote controller) 4 operated by a user, and an input unit 9. The remote control signal includes a command signal for the user to remotely control PJ1. The input unit 9 includes two or more input ports. Assuming that different types of video signals can be input from each port, the screen 6 has two or more windows for projecting (displaying) different images. Assume that there is a (region).

  A digital transmission path 3 and an analog transmission path 7 are connected to the input unit 9. The digital transmission path 3 includes a plurality of cables. Each cable transmits a signal conforming to HDMI between each of the external digital signal supply devices 2D and the PJ1. Each cable is connected to each input port of the input unit 9.

  The analog transmission path 7 includes a plurality of wired or wireless transmission paths. Each transmission path transmits a signal between each of the analog signal supply devices 2A and PJ1. An A / D converter 5 is connected on each transmission path. The A / D converter 5 converts the analog signal transmitted from the analog signal supply device 2 </ b> A into a digital signal, and outputs the converted signal to the input unit 9. Each transmission path of the analog transmission 7 is connected to each input port of the input unit 9.

  Here, it is assumed that the digital signal supply device 2D is a device that outputs a digital signal such as a DVD playback device or a Blue-Ray disc playback device, and the analog signal supply device 2A is a device that outputs an analog signal such as a computer. To do.

  In order to simplify the explanation, it is assumed that the analog signal transmitted from the analog signal supply device 2A is a video signal, and the digital signal transmitted from the digital signal supply device 2D includes authentication information about the video signal and HDCP. Suppose. Although an audio signal is transmitted together with the video signal, the description of the transmission of the audio signal and the audio signal processing in PJ1 is omitted for the sake of simplicity.

  Referring to FIG. 2, PJ 1 receives and outputs an analog video signal such as Video, S-Video, and component given from input unit 9 and outputs the video signal output from receiver unit 10. The video signal processing circuit 11 that processes and outputs the signal for the image, the image signal based on the information provided from the microcomputer 13 is superimposed on the video signal output from the video signal processing circuit 11, and is superimposed An OSD (On Screen Display) circuit 50 that outputs a subsequent video signal, a video signal output from the OSD circuit 50, an analog signal, a DAC (Digital Analog Converter) 12 that outputs the analog signal, and PJ1 are controlled. Microcomputer (microcomputer) 13, liquid crystal display drive unit 14, optical system 15, plugged into AC (Alternating Current) power source not shown Via lug 18 is supplied with the power source includes a lamp 16 removably attached to PJ1 via the power supply unit 17, and the connector 19 supplies the received power to each part of the PJ1.

  The microcomputer 13 generates and outputs switching signals 201 and 202 based on a command signal input from the remote controller 4 via the remote control receiver 20.

  The receiver unit 10 has an ADC (Analog Digital Converter) function for converting a received digital video signal into an analog signal, an authentication function according to HDCP, and a decryption function for encryption.

  Here, the HDCP authentication function applied to this embodiment will be described. HDCP is used to realize encryption of data transmitted in accordance with HDMI. Thereby, it is possible to prevent content such as a video signal transmitted on the digital transmission path 3 from being illegally copied. Here, the digital transmission path 3 is a path for transmitting data and signals according to HDMI, but may be a transmission path according to DVI (Digital Visual Interface).

  In the transmission data / signal protection by HDCP, first, the transmission side (digital signal supply device 2D) communicates with the reception side (PJ1) bidirectionally to exchange information for mutual authentication. Based on the information, the transmitting side authenticates the receiving side. As a result of the authentication, if the receiving side can be authenticated, the transmitting side encrypts the digital video signal using a key that is previously held, and then transmits the digital video signal to the receiving side via the digital transmission path 3. The receiving side decrypts the cipher using a previously shared key. If the transmission side cannot authenticate the reception side, the transmission side rejects transmission of the digital video signal to the reception side, so that the video signal is not transmitted to the reception side.

  In PJ 1, the liquid crystal display driving unit 14, the optical system 15, and the lamp 16 correspond to a projecting unit for projecting an image on the screen 6 under the control of the microcomputer 13 in accordance with the image signal output from the DAC 12.

  The operation of the projection unit will be described. The lamp 16 that is an illuminating device is composed of, for example, an ultrahigh pressure mercury lamp, a metal halide lamp, a xenon lamp, or the like. From the lamp 16, the light becomes substantially parallel light and is emitted to the liquid crystal display driving unit 14.

  The liquid crystal display driving unit 14 includes an optical system including a lens and a prism (not shown) and R, G, and B liquid crystal panels. In the liquid crystal display driving unit 14, the light from the lamp 16 that has passed through an internal lens system (not shown) is incident on each of the R, G, and B liquid crystal panels so that the light quantity distribution is uniform. Of the light incident through the lens system, light in the blue wavelength band (hereinafter referred to as “B light”), light in the red wavelength band (hereinafter referred to as “R light”), and light in the green wavelength band (hereinafter referred to as “R light”). ("G light") enters the R, G, and B liquid crystal panels as substantially parallel light. Each liquid crystal panel is driven in accordance with video signals corresponding to R, G, and B supplied from the DAC 12, and modulates light in accordance with the driving state. The R light, G light, and B light modulated by the liquid crystal panel are color-combined by the dichroic prism and then enlarged and projected on the screen 6 by the projection lens. The projection lens adjusts the zoom state and the focus state of the projection image by displacing a part of the lens group for forming the projection light on the screen 6 that is the projection surface and a part of the lens group in the optical axis direction. The actuator is provided.

  FIG. 3 is a diagram showing in detail a part of FIG. 2 (input unit 9, receiver unit 10, video signal processing circuit 11). In FIG. 3, the direction of the arrow indicating the data / signal transmission direction connecting the input unit 9 and the receiver unit 10 is originally bi-directional for the above-described authentication processing by the HDCP bi-directional communication. However, here, the illustration is omitted, and a one-way arrow indicating only the communication direction of the video signal is used.

  Referring to FIG. 3, input unit 9 includes input ports 9A1, 9A2, 9A3, 9D1, 9D2, 9D3 and 9D4. The analog signal supply device 2 </ b> A is connected to each of the input ports 9 </ b> A <b> 1 to 9 </ b> A <b> 3 through each transmission path of the analog transmission path 7. Further, the digital signal supply device 2D is connected to each of the input ports 9D1 to 9D4 by the cables of the digital transmission path 3. An analog or digital video signal is supplied from the connected analog or digital signal supply device 2A or 2D to each input port, and the supplied signal is input.

  Here, the input port 9A1 inputs a composite video signal, the input port 9A2 inputs a component signal, and the input port 9A3 inputs an S-VIDEO signal. Assume that the input port receives different types of video signals.

  Based on the switching signal 201, the receiver unit 10 selects only the number of ports of the display destination window from the digital video signal input ports 9D1 to 9D4, and selects the digital video signal supplied to the selected input port. , And operates so as to lead to the video signal processing circuit 11 on the output side. The receiver unit 10 includes switches 21 and 22 and receivers 23 and 24 connected to the output sides of the switches 21 and 22. Specifically, the switches 21 and 22 are connected to the input ports 9D1 to 9D4, respectively, and select one of the input ports according to the switching signal 201 given from the microcomputer 13 and select the selected input port. Is connected to the output side of the switch. Accordingly, each of the switches 21 and 22 operates so as to connect the selected input port and each of the receivers 23 and 24.

  Receivers 23 and 24 include authentication circuits 231 and 241, respectively. The authentication circuits 231 and 241 are both connected to the digital signal supply device 2D that supplies signals to the input ports connected via the switches 21 and 22, the switches 21 and 22, the input ports, and the digital transmission path 3. The authentication process is performed in accordance with the HDCP procedure using the authentication information while communicating in the direction.

  Each of the authentication circuits 231 and 241 switches the input port based on the switching signal 201 every time the switches 21 and 22 input the switching signal 201. It transmits to the connected digital signal supply apparatus 2D. The digital signal supply device 2D that has received the authentication request executes the above-described authentication processing, and transmits the authentication result to the authentication circuits 231 and 241 that are the request sources. The authentication circuits 231 and 241 receive the authentication result, generate an authentication detection signal 251 indicating the received authentication result (whether or not the authentication is successful), and output it to the microcomputer 13. Information that identifies the port that has received the signal by the input unit 9 is attached to the signal input from the input unit 9 by the receiver 10. Therefore, the authentication circuits 231 and 241 identify, based on the input signal, the identification information of the port to which the digital signal supply device 2D that has successfully authenticated PJ1 among the digital input ports 9D1 to 9D4 is connected to the authentication detection signal 251. (Port number, etc.) are included.

  After successful authentication, transmission of the encrypted digital video signal is started from the digital signal supply device 2D connected to the selected input port, so that the receivers 23 and 24 receive the video via the selected input port. The signal is input, decrypted using a key that is held in advance, and then output to the video signal processing circuit 11.

  In FIG. 3, it is assumed that the switches 21 and 22 satisfy the electrical characteristics defined by HDMI specification (specifications) such as input differential impedance.

  FIG. 4 shows details of the video signal processing circuit 11 of FIG. Based on the switching signal 202, the video signal processing circuit 11 performs an operation of assigning a window as a display destination to an input video signal. The input video signal includes a digital video signal input from the receiver unit 10 and an analog video signal input from the input unit 9.

  Referring to FIG. 4, the video signal processing circuit 11 includes a multiplexer 40 for the above-described allocation, a main memory 37 and a sub memory 38, which are buffer memories corresponding to the video signal image memory, and a combining unit 39. The main memory 37 stores the video to be displayed in the main window for each frame, and the sub memory 38 stores the video to be displayed in the sub window for each frame. The video signals read from the main memory 37 and the sub memory 38 are output to the DAC 12 after being combined by the combining unit 39.

  The multiplexer 40 includes a group of logic gates connected in multiple stages (not shown). The analog video signal input ports 9A1, 9A2 and 9A3 connected to the input stage of the logic gate group are connected, and the analog input unit 31 for inputting the analog video signal received at these ports and the output of the receiver 23 are output. A first digital input section 32 for inputting a digital video signal, a second digital input section 33 for inputting a digital video signal output from the receiver 24, a switching input section 34 for inputting a switching signal 202 given from the microcomputer 13, and a main memory 37 Main output terminal 35 to which the sub memory 38 is connected and a sub output terminal 36 to which the sub memory 38 is connected. Here, it is assumed that an analog video signal is supplied to only one of the input ports 9A1, 9A2, and 9A3.

  The main memory 37 stores only video signal data having a size corresponding to the main window among video signals for each frame output from the main output terminal 35. Similarly, the sub memory 38 stores only data of a video signal having a size corresponding to the sub window among video signals for each frame output from the sub output terminal 36. The video signal data for each frame may be stored after being reduced so as to match the size of the corresponding memory.

  Data read from the main memory 37 and the sub memory 38 is given to the synthesis unit 39. The synthesizer 39 synthesizes a digital video signal for one frame to be displayed on the screen 6 based on the given data. The video signal for one frame obtained by the synthesis is output to the DAC 12 via the OSD circuit 50.

  In operation, the multiplexer 40 switches the signals to be derived to the main and sub output terminals 35 and 36 among the signals input from the analog input unit 31 and the first and second digital input units 32 and 33, respectively. Determine based on signal 202. For example, when the switching signal 202 generated based on the command of the remote control signal received by the microcomputer 13 indicates (31, 36/32, 35), the multiplexer 40 receives the analog input from the analog input unit 31 based on the switching signal 202. The operation is performed so that the video signal is derived to the terminal 36 and the analog video signal input from the first digital input unit 32 is derived to the terminal 35. As a result, an image signal (gradation signal) based on the digital video signal constituting the main window is output to the liquid crystal display drive unit 14 via the DAC 12, and an image signal (gradation signal) based on the analog video signal constituting the sub window is generated. The signal is supplied to the liquid crystal display driving unit 14 through the DAC 12.

  The liquid crystal display driving unit 14 drives each liquid crystal panel based on a given video signal for one frame. Thereby, the area corresponding to the main window of each liquid crystal panel is driven based on the gradation signal of the digital video signal read from the main memory 37. Further, the area corresponding to the sub window of each liquid crystal panel is driven based on the gradation signal of the analog video signal read from the sub memory 38. As a result, as shown in FIG. 8, the video by the analog video signal and the digital video signal is simultaneously displayed on the screen 6 in a multi-window.

  According to FIG. 3, the switches 21 and 22 are all connected to the input ports 9D1 to 9D4 to which digital video signals are to be input, and any one of the connected input ports based on the switching signal 201. Are selectively connected to the output. Therefore, the video signal given to any of the input ports 9D1 to 9D4 can be displayed on the main window, and the video signal given to any of the input ports 9D1 to 9D4 can also be displayed on the sub-window. Thus, for example, when the digital video signal of the HDMI input port 9D1 is displayed in the main window, any one of the other HDMI input ports 9D1 to 9D4 can be displayed in the sub window. The restriction on the selection of the video signal to be displayed as shown in FIG.

  In addition, according to the configuration of FIG. 3, even when the video of the HDMI input port 9D1 is displayed in the sub-window, similarly, the signal based on the input video signal of any of the HDMI input ports 9D1 to 9D4 is simultaneously displayed on the main window. Can be displayed.

  Further, the video signal to be displayed can be switched for each window by the combination of the switching signals 201 and 202. For example, when the video of the HDMI input port 9D1 is displayed in the main window, the user operates the remote controller 4 to switch the video in the main window to the video of the analog input port 9A2. If the command is transmitted, the video of the main window can be switched from the digital video signal to the analog video signal by the switching signals 201 and 202 generated by the microcomputer 13 according to the command.

  Further, the following switching is possible by a combination of switching signals 201 and 202 generated based on a command given by the user. That is, when the video of the HDMI input port 9D1 is displayed in the main window and the video of the HDMI input port 9D2 is displayed in the subwindow, the video signal to be displayed is changed by outputting the new switching signal 202. Without switching the display window of the video signal. That is, the video of the input port 9D2 can be displayed by switching from the sub window to the main window, and the video signal of the input port 9D1 can be displayed by switching from the main window to the sub window.

(Selection of certified video signal)
A configuration for selecting and displaying an authenticated video signal according to HDCP will be described.

  For example, the video signal of the HDMI input port 9D1 is displayed on the main window using the switch 21 and the receiver 23, and the video signal of the analog input port 9A1 is displayed on the subwindow, and the HDMI input ports 9D2 to 9D4 are displayed. It is assumed that the digital signal supply device 2D is connected to any one or more of the above. In this case, based on the switching signal 201, the digital signal supply device 2D connected to one selected from the input ports 9D2 to 9D4 by the switch 22 performs an authentication process on the PJ1. The authentication circuit 241 receives the authentication result, generates an authentication detection signal 251 based on the received authentication result, and outputs it to the microcomputer 13. If the authentication is successful, the authentication detection signal 251 includes identification information of the input port selectively connected by the switch 22. The microcomputer 13 stores the identification information of the input port indicated by the authentication detection signal 251 in the internal memory.

  The microcomputer 13 generates an image signal to be superimposed on the video based on the identification information of the input port indicated by the input authentication detection signal 251 and outputs the signal to the OSD circuit 50. The OSD circuit 50 superimposes the image signal given from the microcomputer 13 on the video signal for one frame input from the video signal processing circuit 11 and outputs the superimposed video signal. As a result, the message 26 is displayed on the screen 6 together with the display of the video in the main window 27 and the sub-window 28 as shown in FIG. The message 26 is information displayed by being superimposed on the video by the OSD circuit 50. Based on the authentication detection signal 251 output from the authentication circuit 241, the message 26 is sent to the third input port 9D3 among the HDMI input ports 9D1 to 9D4. The connected digital signal supply device 2D has already authenticated PJ1 (successful authentication), and the user is notified that the video signal is started to be transmitted from the digital signal supply device 2D and received by the input port 9D3. Notification is made (see FIG. 5).

  If the authentication is not successful, a message “No authenticated port” is displayed as the message 26.

  The user who confirmed the display of FIG. 5 inputs a command indicating switching to the authenticated input port (in the case of FIG. 5, input port 9D3) indicated by the message 26 in order to switch the video to be displayed in the main window or the sub window. To do. The microcomputer 13 analyzes the received command, generates a switching signal 201 or 202 based on the analysis result, and outputs it. Further, the microcomputer 13 compares the identification information of the input port specified by the user obtained by the analysis with the identification information of the authenticated input port stored in the internal memory. If a match is determined based on the comparison result, an instruction for omitting the authentication process is output to the authentication circuit 241 that is the output source of the authentication detection signal 251 including the identification information of the input port. In response to an instruction to omit authentication, the authentication circuit 241 omits an authentication request transmission even if there is an instruction to switch the input port of the video signal.

  As a result, when an instruction to switch to receive a digital video signal to be displayed is received from the input port to which the authenticated digital signal supply device 2D is connected, the authentication process is omitted. The video signal to be displayed can be quickly switched without such a waiting time.

(Video signal switching procedure)
With reference to FIG. 6, the procedure of switching the input video signal by the circuit of FIG. 3 will be described. It is assumed that one or more analog signal supply devices 2A and one or more digital signal supply devices 2D are connected to the input port of the input unit 9.

  First, when receiving a command signal via the remote control receiver 20, the microcomputer 13 generates and outputs switching signals 201 and 202 based on the command signal (step S3). Next, the switches 21 and 22 select the designated input port based on the applied switching signal 201. As a result, the selected input port is connected to the receivers 23 and 24 on the output side (step S5). In the receivers 23 and 24, the above-described authentication processing is performed by the authentication circuits 231 and 241 (step S7). That is, the authentication circuits 231 and 241 transmit an authentication start request. In the connected digital signal supply device 2D, the authentication process of PJ1 is executed in response to the request. The authentication circuits 231 and 241 receive the authentication result and output an authentication detection signal 251 to the microcomputer 13.

  Subsequently, the multiplexer 40 receives the video signal to be displayed in the main window and the sub window based on the supplied switching signal 202 in the analog input unit 31 and the first and second digital input units 32 and 33. It selects from among and outputs (step S9). Thereby, the video signal to be displayed in each window specified by the switching signals 201 and 202 can be assigned by the synthesis unit 39, and a digital video signal for one frame is synthesized and output.

  An image is displayed (projected) on the screen 6 according to the synthesized image signal for one frame (step S11). In this display, the OSD circuit 50 simultaneously displays the identification information of the authenticated input port indicated by the authentication detection signal 251 (see FIG. 5).

(Other configurations)
In the present embodiment, PJ1 is remotely controlled by remote controller 4, but PJ1 is provided with an operation panel (such as an integrated display unit using liquid crystal), and the user operates the operation panel to input commands. You may do it. At the time of command input, a menu screen for command input may be displayed on the operation panel or the display unit of the remote controller 4 and may be selected and input. Alternatively, the menu screen may be displayed by the OSD 50 when displaying an image on the screen 6, and the user may select and input a command based on the displayed menu.

  In the present embodiment, the switch signal 201 selects a video signal of a different input port for the switches 21 and 22, but a video signal of the same input port may be selected. In this case, the same video can be displayed in the main window and the subwindow.

  The output mode for notifying the message 26 is not limited to the mode of displaying it superimposed on the image of the screen 6. For example, an LED (Light Emitting Diode) or LCD (Liquid Crystal Display) provided on the main body of the PJ 1 is used. May be displayed.

  Further, whether to display the message 26 superimposed on the video may be switched based on a command given from the user's remote control 4.

  Further, the arrangement of the windows for displaying different video signals is not limited to the aspect of being arranged side by side in FIG. 8, and may be an aspect of being arranged in parallel vertically, or may be an aspect in which subwindows are arranged in the main window. Also good. The window size may be different as in the present embodiment, but may be the same size. The video displayed in each window can be either a moving image or a still image.

  The receiver 10 may be composed of a one-chip IC (integrated circuit). Further, the present embodiment is not limited to the case where two different videos are displayed on the screen 6, and the present embodiment can be similarly applied to the case where three or more different video signals are displayed simultaneously.

  The multiplexer 40 switches inputs by a logic gate group, but the logic gate group may be replaced by a program for executing the configuration / operation.

  The video display device according to the present embodiment is not limited to a liquid crystal projector, but is also applicable to a projector using LCOS (Liquid crystal on silicon) or DLP (Digital Light Processing) (registered trademark), or a television system. Is possible.

(Effect of embodiment)
According to the present embodiment, when an image is projected (displayed) simultaneously on each of N (N is an integer of 2 or more) windows (corresponding to a projection area and a display area), it becomes a candidate to be projected for each window. The number of ports for inputting video signals is the same number of M (M is an integer of 2 or more), and there is no restriction on the number of input ports for each window. Further, the number of switches and receivers with respect to the number of input ports can be reduced as compared with the conventional case, and the cost of the PJ1 itself can be reduced.

  In addition, it is possible to promptly switch the displayable video signal by notifying the user of information specifying the HDCP authenticated input port.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 1 Projector (PJ), 2A Analog signal supply apparatus, 2D digital signal supply apparatus, 3 Digital transmission line, 4 Remote control, 9 Input part, 10 Receiver part, 11 Video signal processing circuit, 13 Microcomputer, 21,22 Switch, 23, 24 receiver, 26 message, 40 multiplexer, 50 OSD circuit, 201, 202 switching signal, 251 authentication detection signal.

Claims (8)

A video display device that displays video in each of N (N is an integer of 2 or more) display areas,
An input unit including M (M is an integer of 2 or more) input ports and inputting an externally supplied video signal via each of the input ports;
A receiving unit that selects and outputs N video signals from the M video signals input by the input unit;
An allocation unit that allocates display destinations of each of the N video signals output from the receiving unit to the N display areas,
The receiving unit
Including N selection parts,
Each of the selection units is a video display device that selects and outputs one video signal from among M video signals based on a first signal given from outside.   2. The video display device according to claim 1, wherein the allocation unit allocates a display destination of each of the N video signals to each of the N display areas based on the second signal given from the outside. The M input ports include a first input port,
The first input port is connected to a signal supply device that starts authentication processing of the video display device in response to an authentication request, and starts supplying a video signal to the video display device when authentication is successful,
The accepting unit includes an authentication unit that detects a result of the authentication processing by the signal supply device connected to the first input port,
The video display apparatus according to claim 2, wherein the content detected by the authentication unit is output.   The video display device according to claim 3, wherein the detected content includes identification information of the first input port.   The video display device according to claim 4, wherein the detection content is displayed simultaneously with the display of the video in the N display areas. The authentication unit
Prior to receiving a video signal via the first input port, the authentication request is transmitted to the signal supply device via the first input port for the authentication process,
When the first signal or the second signal instructing to receive a video signal is given from the first input port to which the signal supply device that has been successfully authenticated is connected, the authentication unit The video display device according to claim 5, wherein transmission of the authentication request is omitted. The M input ports include an input port to which an analog video signal is supplied and an input port to which a digital video signal is supplied,
The video display device according to claim 6, wherein the first input port indicates a port to which a digital video signal is input. A display image switching method in N (N is an integer of 2 or more) display areas in which images are displayed simultaneously,
Inputting video signals supplied from the outside to M (M is an integer of 2 or more) input ports;
Selecting and outputting N video signals from the input M video signals;
Assigning the display destination of each of the N video signals to be selected and output to each of the N display areas,
The step of selecting and outputting includes:
Including N selection steps,
In each of the N selection steps, a display video switching method of selecting and outputting one video signal from M video signals based on a given first signal.

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