JPH1049068A - Liquid crystal projector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the reliability of a system by allowing connected liquid crystal display projectors to use a memory storing the display parameter of the liquid crystal projector in common, efficiently using the memory and grasping the mutual actuation states of the liquid crystal projectors. SOLUTION: A plurality of liquid crystal projectors are connected and provided with a means mutually transmitting and receiving data between them and a means executing the storing and reading-out action of the memories mutually possessed by them. Thus, when an inputted video signal is changed, not only the data stored in the memory of its own but also the data stored in the memory of the other liquid crystal projector is referred to. When an instruction is received from the outside or some change of the state is detected or at every previously decided term, the instruction is transmitted to the other liquid crystal projector so as to prevent a malfunction from being executed by controlling the other liquid crystal projector or confirming the actuation state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for transmitting and receiving data to and from each other via a communication port when using a plurality of liquid crystal projectors in combination. The present invention relates to a liquid crystal projector whose operation is controlled.

[0002]

2. Description of the Related Art Conventionally, liquid crystal projectors have been
In order to display many video signals with different frequencies and synchronization characteristics such as video signals of various personal computers and workstations in addition to video signals such as PAL and SECAM, liquid crystal panel drive timing signal circuits and liquid crystal projectors A plurality of types of setting data for hardware such as an internal signal processing circuit are stored in a memory, and optimal data is searched from data stored according to an input video signal and set in hardware. Has a function. In many cases, this function is usually automatically executed when a video input signal changes, and is called an auto scan function.

Usually, a liquid crystal projector is often operated independently, but a plurality of liquid crystal projectors are
There are also applications that work in conjunction with one another. In such a case, connect each projector to RS-232.
In most cases, it is connected to an external control device such as a personal computer by a C cable or the like, and is operated by a command from the control device.

FIG. 5 shows an example of a configuration for controlling a plurality of liquid crystal projectors by a conventional method. In this example, the liquid crystal projectors 4 and 5 are controlled by a personal computer 6. Reference numerals 401 and 501 denote microcomputers for controlling the operations of the liquid crystal projectors 4 and 5, and reference numerals 402 and 502 denote memories for storing display parameters. 403 and 503 are timing generation circuits for generating timing signals to be sent to a signal processing circuit and a liquid crystal driving circuit in accordance with the synchronization of the parameters read from the memories 402 and 502 and the set video signals. Reference numerals 404 and 504 denote signal processing circuits for performing signal processing such as gamma correction processing and multi-layer development processing on video signals in accordance with timing signals sent from the timing generation circuit. 405
And 505, a liquid crystal drive circuit for driving a liquid crystal panel by a timing signal sent from a timing generation circuit. 406 and 506 are liquid crystal panels for displaying images.
407 and 507 are lamps for projecting an image reflected on a liquid crystal panel. 408 and 508 are projection lenses. 4
09 and 509 are communication ports for communicating with a personal computer. 410 and 510 are communication cables for communicating with a personal computer. In the conventional method, FIG.
As shown in the example, a communication port for connecting an external control device such as a personal computer is prepared, and each liquid crystal projector is controlled through this communication port.

Further, as shown in FIG. 6, a memory built in each liquid crystal projector is capable of storing display parameters for several channels, and this data can be read and stored from a microcomputer. it can. Further, when the input video signal is switched, a liquid crystal projector having an auto scan function for automatically searching the memory for a display parameter suitable for a new video signal, as shown in FIG. By comparing frequencies and the like, a corresponding display parameter is searched.

The following published technical reports similar to the present invention in the technical field are available. In Japanese Patent Application Laid-Open No. 4-186287, as a means for reducing the size of the device by sharing the main memory and the display memory in the data processing device, the display data is stored in a part of the main memory. , FIF
A method of buffering an out-of-synchronization between access to a main memory and a read cycle of display data by an O memory is shown.

In Japanese Patent Application Laid-Open No. 61-235889,
As a means for displaying the same data from one shared bitmap memory to a plurality of display devices having different display control conditions without any trouble, a method of providing a buffer for holding addresses and data and sharing a memory access circuit is shown. ing. The sharing of the bitmap memory has the effect of reducing the time since only one drawing operation is required.

[0008]

By the way, in a display system using a plurality of liquid crystal projectors, when each of the liquid crystal projectors is controlled by an external control device such as a personal computer as in the prior art, each of the control devices and all the liquid crystals are controlled. It is necessary to connect the projector with a communication cable, so that the cable connection is complicated and the cable itself becomes a hindrance.

Further, since each liquid crystal projector can only refer to its internal memory, it is necessary to store the same signal in each liquid crystal projector even if the display parameters are the same. Therefore, if the memory capacity is for five channels, only five types of signal display parameters can be referred to.

Further, even when the same video signal is input to each liquid crystal projector, the synchronization signal fluctuates depending on the connection status from the signal source to the liquid crystal projector, and as a result, the signal determination result of the auto scan differs in a specific liquid crystal projector. That phenomenon was also happening.

Although the above-mentioned conventional example discloses the sharing of a memory, the former is a sharing of a display bitmap memory and a main memory, which is different from the present invention. In the latter, the display bitmap memory is shared by a plurality of display devices, and the memory for storing the display data itself is shared. Therefore, it is not possible to use such a method that the storage memory of the display parameter is read out from the liquid crystal projector other than itself and referred to.

An object of the present invention is to simplify connection of cables and control memory inside each liquid crystal projector in a display system using a plurality of liquid crystal projectors when controlling with an external control device such as a personal computer. An object of the present invention is to provide a liquid crystal projector that can be used effectively.

Another object of the present invention is to provide a method for avoiding a phenomenon in which, when the same video signal is input to each of the liquid crystal projectors, the result of the auto scan signal determination in a specific liquid crystal projector differs depending on the connection status. I do.

[0014]

According to the present invention, there is provided a communication port for transmitting and receiving data to and from a liquid crystal projector other than its own, and a video signal provided in the liquid crystal projector other than its own and inputted to itself. A first memory for storing parameters adjusted so that the image is projected in an optimal state, reading means for reading the parameters, and provided in its own liquid crystal projector. A second memory for storing display parameters used in the liquid crystal projector of
There is provided a liquid crystal projector comprising transmitting means for reading out display parameters stored in the second memory in accordance with an instruction from a liquid crystal projector other than itself and sending out the display parameters from the communication port.

Further, according to the present invention, detecting means for detecting a change in the type of the input video signal, and detecting the change in the type of the input video signal from the second memory when the change in the type of the input video signal is detected. Searching for display parameters for projecting a signal in an optimal state, and searching for an optimal parameter from the first memory if the optimal parameter cannot be found in the second memory. As a result, a liquid crystal projector is obtained.

Further, according to the present invention, when a command is received from the outside or when a change in an input video signal is detected at predetermined time intervals, the communication with the liquid crystal projector other than itself is performed. A liquid crystal projector is characterized by transmitting a command via a port to control a liquid crystal projector other than itself and, when receiving a command from a liquid crystal projector other than itself, performing an operation according to the command. can get.

[0017]

Therefore, according to the liquid crystal projector of the present invention, the liquid crystal projector has a communication port for transmitting and receiving data to and from the liquid crystal projector other than itself, and is input to the memory in the liquid crystal projector other than itself. Means for storing parameters adjusted to project the video signal in an optimal state, and means for reading out the parameters. By having a means for storing display parameters used in the liquid crystal projector and a means for reading out display parameters stored in the memory in accordance with an instruction from the liquid crystal projector other than itself and sending out the display parameters from the communication port, Shared memory, realizing effective use of memory Kill.

The apparatus further comprises means for detecting a change in the type of the input video signal, and when the change in the type of the input video signal is detected, the input video signal is stored in its own memory in an optimal state. Search for display parameters for projection, and if the optimal parameters cannot be found in the memory of the projector itself, search for the optimal parameters from the memories of the LCD projectors other than the projector to use them alone. It is possible to store and display more kinds of video signal display parameters in the memory than in the case where the video signal is displayed.

Also, every predetermined period, when an external command is received, or when a change in an input video signal is detected, a command is sent to a liquid crystal projector other than itself via a communication port. To control a liquid crystal projector other than itself, and conversely, when receiving a command from a liquid crystal projector other than itself, the operation according to the command is performed, so that an external control device can send a signal to the liquid crystal projector system. One control cable can be used. Further, the reliability of the system can be improved by referring to each other's auto scan determination results.

[0020]

Next, an embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 is a diagram showing an embodiment of the liquid crystal projector of the present invention. In this example, the liquid crystal projectors 1 and 2 are controlled by a personal computer 3. 101 and 201 are microcomputers controlling the operation of the liquid crystal projectors 1 and 2,
102 and 202 are memories for storing display parameters. 103 and 203 are memories 102 and 2
A timing generation circuit for generating a timing signal to be sent to a signal processing circuit or a liquid crystal drive circuit in accordance with the synchronization of the video signal with a parameter read out from O.02. 104 and 204 are signal processing circuits for performing signal processing such as gamma correction processing and multi-layer development processing on video signals in accordance with timing signals sent from the timing generation circuit. 105 and 205 are liquid crystal driving circuits for driving a liquid crystal panel by a timing signal sent from a timing generation circuit.
106 and 206 are liquid crystal panels for displaying images. 10
Reference numerals 7 and 207 denote lamps for projecting an image reflected on a liquid crystal panel. 108 and 208 are projection lenses. 10
Communication ports 9, 110 and 209, 210 are used for communication between the personal computer and another liquid crystal projector. 111
And 211 are communication cables for performing communication with a personal computer.

The microcomputer 101 of the liquid crystal projector 1
Upon receiving a command from the personal computer 3, it controls its own operation in accordance with the command and sends the command received from the personal computer 3 to the liquid crystal projector 2 from the communication port 110. The microcomputer 201 of the liquid crystal projector 2 is the microcomputer 1
When receiving the command from 01, the operation of the liquid crystal projector 2 is controlled according to the command. In the example of FIG. 1, the command is sent from the personal computer to the liquid crystal projector. However, the command may be sent using an operation key of the liquid crystal projector 1 or a remote controller connected to the liquid crystal projector 1.

In the present invention, when the display parameters are stored in the memory or read out from the memory,
In addition to accessing the memory of the liquid crystal projector itself as shown by the arrow 10 or 20 in FIG.
As shown by the arrows 1 or 21, the memories inside the other liquid crystal projectors can also be accessed via the communication ports 110 and 209. Further, the memory of the liquid crystal projector other than itself can be referred to by the auto scan function. For example, if the memory is searched in the order as indicated by an arrow 12 or 22 in FIG. You can choose one.

FIG. 3 shows an example of a command sequence used for communication between the liquid crystal projectors or between the personal computer and the liquid crystal projector in the present invention. Here, COM has an application range of the control command, that is, has a value of 1 when all connected liquid crystal projectors are targets, and has a value of 0 when only one device specified by an ID described later is a target. The ID is a code for designating a liquid crystal projector to be controlled. A unique number is set in advance for each liquid crystal projector, and when the ID matches the ID, the command is accepted. FNC is a code indicating the content of the command, PARA is a parameter accompanying the command,
CKS is a checksum for checking a command transmission error, and is, for example, the lower 1 byte of the sum of data from COM to immediately before CKS.

FIG. 4 is a flowchart showing a processing flow when the microcomputer of the liquid crystal projector receives a command sequence as shown in FIG. When a command string is received (step S101), it is checked whether COM is 1 or 0 (step S102). If COM = 1, all liquid crystal projectors are to be controlled.
The command designated by C is executed (Step S103).
If COM = 0, it is checked whether or not the ID matches the number assigned to itself (step S104). If they match, the command specified by the FNC is executed (step S103). If the IDs do not match, the command is not executed. Thereafter, the received command sequence is transmitted to another connected liquid crystal projector (step S10).
5). If such processing is performed by all the liquid crystal projectors, it is possible to control the same number of liquid crystal projectors as when two liquid crystal projectors are connected.

Further, one of a plurality of connected liquid crystal projectors sends a command to other liquid crystal projectors at regular intervals or when a certain state change occurs, and grasps the operation state of each liquid crystal projector. If, for example, the same video signal is input, but only one of them receives a different judgment result in the auto scan, the auto scan of another liquid crystal projector may be performed. Correct display parameters can be set with reference to the determination result, and the reliability of the system can be improved.

[0026]

As is apparent from the above description, according to the liquid crystal projector of the present invention, the liquid crystal projector has a communication port for transmitting and receiving data to and from a liquid crystal projector other than itself, and a memory in the liquid crystal projector other than itself. Has means for storing the parameters adjusted so that the video signal input thereto is projected in an optimal state, and means for reading out the parameters. Means for storing display parameters to be used by a liquid crystal projector other than its own in its own memory, and means for reading out display parameters stored in said memory in accordance with an instruction from a liquid crystal projector other than its own and transmitting it from said communication port. By sharing the memory inside the LCD projector other than itself with each other Becomes possible, it is possible to effectively utilize the memory.

The apparatus further comprises means for detecting a change in the type of the input video signal, and when the change in the type of the input video signal is detected, the input video signal is stored in its own memory in an optimal state. Search for display parameters for projection, and if the optimal parameters cannot be found in the memory of the projector itself, search for the optimal parameters from the memories of the LCD projectors other than the projector to use them alone. It is possible to store and display more kinds of video signal display parameters in the memory than in the case where the video signal is displayed.

Also, at predetermined time intervals, when a state change is detected, or when an external command is received, a command is transmitted to a liquid crystal projector other than itself via the communication port to transmit the command. When a command is received from a liquid crystal projector other than its own, the operation according to the command is performed to connect a control cable from the external control device to the liquid crystal projector system. Not only is there a merit that the number can be reduced, but also the reliability of the system can be improved by referring to each other's auto scan determination results.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a system configuration using a liquid crystal projector of the present invention.

FIG. 2 is an explanatory diagram showing a state of memory reference when the liquid crystal projector of the present invention is used.

FIG. 3 is an explanatory diagram showing an example of a control command sequence when the liquid crystal projector of the present invention is used.

FIG. 4 is an explanatory diagram showing an example of a processing flow when a control command sequence is received when the liquid crystal projector of the present invention is used.

FIG. 5 is an explanatory diagram showing an embodiment of a system configuration using a conventional liquid crystal projector.

FIG. 6 is an explanatory view showing a state of memory reference when a conventional liquid crystal projector is used.

[Explanation of symbols]

1, 2, 4, 5 Liquid crystal projector 3, 6 Personal computer 101, 201, 401, 501 Microcomputer 102, 202, 402, 502 Memory 103, 203, 403, 503 Timing generation circuit 104, 204, 404, 504 Signal processing circuit 105 , 205, 405, 505 Liquid crystal drive circuit 106, 206, 406, 506 Liquid crystal panel 107, 207, 407, 507 Lamp 108, 208, 408, 508 Projection lens 109, 110, 209, 210, 409, 509
Communication port 211, 410, 510 Communication cable

Claims (3)

[Claims] 1. A communication port for transmitting / receiving data to / from a liquid crystal projector other than itself, and an adjustment provided so as to be provided in the liquid crystal projector other than itself and projecting a video signal input to itself in an optimal state. A first memory for storing the set parameters, reading means for reading the parameters, and display parameters provided in the own liquid crystal projector and used by other liquid crystal projectors in accordance with an instruction from the other liquid crystal projector. A second memory, and transmission means for reading display parameters stored in the second memory in accordance with an instruction from a liquid crystal projector other than the second memory and transmitting the display parameters from the communication port. LCD projector. 2. A detecting means for detecting that the type of the input video signal has changed, and detecting an input video signal from the second memory in an optimal state when detecting a change in the type of the input video signal. 2. A display parameter for projection is searched, and when an optimum parameter is not found in the second memory, an optimum parameter is searched from the first memory. The liquid crystal projector as described. 3. When a command is received from the outside, or when a change in an input video signal is detected, a command is sent to a liquid crystal projector other than itself via the communication port at predetermined intervals. The liquid crystal projector according to claim 1, wherein the liquid crystal projector controls the liquid crystal projector other than the self, and when receiving a command from the liquid crystal projector other than the self, performs an operation according to the command. .