CN1856062B

CN1856062B - Projection image display device

Info

Publication number: CN1856062B
Application number: CN2006100781798A
Authority: CN
Inventors: 中村达朗; 高辻昌晃; 丸山敦
Original assignee: Hitachi Ltd
Current assignee: Maxell Ltd
Priority date: 2005-04-28
Filing date: 2006-04-28
Publication date: 2010-08-25
Anticipated expiration: 2026-04-28
Also published as: CN1856062A; JP4826130B2; JP2006308826A

Abstract

A theft preventing system easy to operate and capable of implementing countermeasures to theft of a projection type image display device is provided. The projection type image display device is equipped with a unit for detecting a used condition of the device and a unit for registering a used condition of the device. By further equipping the device with a unit for inhibiting normal operations of the device in its used condition other than the registered condition, a simple and easy-to-operate unauthorized use preventing system can be realized and thus protection of the device against theft can be attained.

Description

Projection type image display apparatus

Technical Field

The present invention relates to a projection type image display apparatus having a function of preventing unauthorized use.

Background

In recent years, projection type image display devices such as projectors have been rapidly spread in various scenes such as introduction in conferences, explanation in educational fields, home theater appreciation in homes, and the like, but have been increasingly fatally damaged by theft because of their high prices and their relatively simple holding and operation. As a countermeasure against theft and against unauthorized use, each manufacturer company is equipped with a screen lock function for invalidating a setting change by setting a password. As such a technique, for example, it is disclosed in japanese patent laid-open publication No. 2004-77967.

In the technique disclosed in japanese patent laid-open No. 2004-77967, a user is required to input a password when the device is started, and only when the password matches a password preset by a legitimate user, the operation is permitted, thereby preventing the improper use of the device. However, even when the owner is in a proper condition, the owner also needs to input a password input procedure for confirming the password of the owner one by one, which makes the operation very complicated.

Disclosure of Invention

The invention provides a projection type image display device having a function of preventing unauthorized use while suppressing a reduction in operability.

As an example of the present invention, in a projection type image display apparatus, first information indicating a use state thereof is stored in a memory, and when a second use state detected by a detector for detecting the use state of the projection type image display apparatus at a predetermined timing based on the first information in the memory is different from the use state indicated by the first information, use of the projection type image display apparatus is restricted.

Another example of the present invention is a projection type image display apparatus including a setting value of a specific function of the projection type image display apparatus is recorded in a memory at a first timing, and when a processor detects that a change of the setting value is performed, the projection type image display apparatus is restricted from using an improper use prevention system.

Drawings

Fig. 1 is a block diagram showing a projection type image display apparatus according to a first embodiment.

Fig. 2 is an operation sequence diagram showing a startup setting process of the unauthorized use prevention system.

Fig. 3 is a diagram showing an example of password registration.

Fig. 4 is an operation sequence diagram showing an operation process of the unauthorized use prevention system.

Fig. 5 is a diagram showing an example of password input.

Fig. 6 is a view showing an example of mounting the angle sensor.

Fig. 7 is a diagram showing a state of overhead suspension in the projection type image display apparatus.

Fig. 8 is a diagram showing an example of warning generated by a logo print.

Fig. 9 is a block diagram showing a projection type image display apparatus according to a second embodiment.

Fig. 10 is a block diagram showing a projection type image display apparatus according to a third embodiment.

Fig. 11 is a block diagram showing a projection type image display apparatus according to a fourth embodiment.

Fig. 12 is a diagram showing a fourth embodiment.

Fig. 13 is a block diagram showing a projection type image display apparatus according to a sixth embodiment.

Fig. 14 is a block diagram showing a projection type image display apparatus according to a seventh embodiment.

Fig. 15 is a diagram showing a fixed state of the projection type image display apparatus.

Fig. 16 is a block diagram showing a projection type image display apparatus according to an eighth embodiment.

Fig. 17 is a diagram showing the release of the unauthorized use prevention system by the remote controller as the tenth embodiment.

Fig. 18 is a diagram showing a vertical reverse processing screen according to the twelfth embodiment.

Fig. 19 is a diagram showing a scramble processed screen according to the twelfth embodiment.

Fig. 20 is a diagram showing a blank screen in the twelfth embodiment.

Fig. 21 is a block diagram showing a projection type image display apparatus of an embodiment for issuing an alarm according to the twelfth embodiment.

Fig. 22 is a diagram of raising an alarm of the twelfth embodiment.

Fig. 23 is a block diagram showing a projection type image display apparatus according to a thirteenth embodiment.

Fig. 24 is a diagram showing an example of warning generated by lighting of an LED in the thirteenth embodiment.

Fig. 25 is a diagram showing a correction value storage area of the nonvolatile memory 103 in the ninth embodiment.

Detailed Description

In the following, the best mode of the present invention will be described with reference to the accompanying drawings. In the drawings described below, elements having common functions are denoted by the same reference numerals, and the function that has been described once is not described repeatedly.

In the embodiments of the invention described below, a system for preventing unauthorized use after theft is realized by detecting a change in the installation state or the setting state of a projection type image display apparatus (hereinafter, the projection type image display apparatus may be simply omitted as "apparatus" unless it is understood that the change is not a case). The device installation state and the setting state include various states in which a state change can be detected. For example, as shown in table 1, the setting states include (1) a setting posture, (2) a setting direction, (3) a setting place, (4) an input state to an input terminal, and (5) a fixed state, and the setting states include (1) a focus/zoom setting state of a projection lens, (2) a projection image distortion correction value, and (3) a projection image inversion setting state, for example. As shown in table 1, the object of detecting the state change differs for each state. We will explain their details later. Hereinafter, these states are collectively referred to as "use states" of the projection type image display apparatus.

TABLE 1

In the present embodiment, theft is estimated by a change in the installation state (installation posture here) of the device, and authentication of the user (for example, determination by inputting a password) is performed only when there is a change, so that the troublesome operation (procedure) of the authentication check which always exists in the prior art is simplified, the frequency of occurrence of the opportunity of the authentication check is reduced, and the degree of complication of the operation is reduced.

Fig. 1 is a block diagram showing a projection type image display apparatus according to a first embodiment. In fig. 1, reference numeral 101 denotes a projection type image display apparatus, 111 denotes an input terminal to which an image signal (not shown in the drawing) is input, 110 denotes an input signal processing I/F that performs predetermined signal processing on the image signal input from the

input terminal

111, 104 denotes an image processing unit that performs image processing such as decoding and conversion on the image signal output from the input signal processing I/F110 and displays the image on a screen, 112 denotes a projection optical unit that enlarges and projects the image processed in the

image processing unit

104, and 113 denotes a screen that projects the projected image. Reference numeral 105 denotes an operation button composed of a plurality of buttons arranged in a housing of the apparatus not shown in the drawing, 106 denotes a remote controller (hereinafter, simply referred to as "remote controller") for remotely controlling the projection type image display apparatus by an Infrared (Infrared) remote control signal (hereinafter, simply referred to as "IR remote control signal"), 107 denotes an IR light receiving element for receiving the IR remote control signal from the

remote controller

106, 108 denotes an angle sensor as a means for detecting an installation angle of the apparatus with respect to gravity and reading a change in the installation posture of the apparatus from a change in the detected value, 109 denotes an I/O controller for controlling an input from the IR light receiving element 107 and the

angle sensor

108, 102 denotes a Central Processing Unit (hereinafter, simply referred to as "CPU") for performing calculation control of the entire projection type image display apparatus, 103 denotes a memory for storing various data such as a program for controlling the CPU102 and a password and a use state of the apparatus, an image signal (not shown) input from the input terminal 111 is subjected to predetermined processing in the input signal processing I/F110 and the image processing unit 104, and an optical image (image) corresponding to the image signal is projected onto, for example, a screen 113 by the projection optical unit 112. The on/off of the device and the operations of the functions, settings, and the like provided in the device are performed by the operation buttons 105 or the remote controller 106, and the CPU102 performs corresponding processes in accordance with IR remote control signals received via the operated buttons (not shown) of the operation buttons 105 or the IR light receiving element 107 and the I/O controller 109.

For example, in the case where the start (activation) of the improper use prevention system for preventing the improper use of the projection type image display apparatus is set by the operation of the operation button 5 in advance, when the apparatus is turned on to start (activate), the CPU102 acquires the set angle of the projection type image display apparatus detected by the angle sensor 108 through the I/O controller 109. The amount of change in the installation posture is calculated by comparing the acquired installation angle with the installation angle registered in the memory 103 by a legitimate user in advance. The CPU102 determines whether or not the theft is present based on the change amount, and determines whether or not the user authentication is performed. CPU102, when judging that the authentication is not required, permits the subsequent operations, and when not, authenticates the user, and permits the operation of the apparatus if a password registered in advance by a qualified user in memory 103 is inputted by, for example, an operation of operation button 105. We will describe the above-described processing of the CPU102 in detail later with an operation program diagram.

The angle sensor includes an angle detection axis having one, two, and three axes, but any of the angle sensors 108 may be used. Examples of the memory 103 for storing the detected installation angle data include an EEPROM and a FLASHROM. In the case where the CPU102 incorporates a function equivalent to that of the I/O controller 109, each device connected to the I/O controller may be directly connected to the CPU.

Next, the processing operation of the CPU102 relating to the abuse prevention system will be described with reference to the operation program of fig. 2 and 4. Fig. 2 is an operation sequence diagram showing a start (activation) setting process of the unauthorized use prevention system. When an instruction to activate the unauthorized use prevention system is issued via the operation button 105 or the remote controller 106 in fig. 1 after the power is turned on, the CPU102 starts the activation setting processing of the unauthorized use prevention system in step (hereinafter abbreviated as "S") 201, and detects the device use state at that time, the setting angle α in the setting posture shown in fig. 3 in the present embodiment, via the I/O controller 109 by the angle sensor 108 and registers the detected setting angle α in the memory 103 (S202). Next, as shown in fig. 3, the image processing section 104 displays a password registration request screen to urge the user to register a password for authentication. Further, when password registration is completed by the user by operating the button 105 or the remote controller 106, the CPU102 registers the password in the memory 103 (S203). Here, the password refers to a serial number that sequentially designates an arrangement of numerals and characters, a specific figure displayed, or a specific button/remote controller key pressed. Next, the projection type image display apparatus is registered in the memory 103 in a state where the unauthorized use prevention system is activated (S204), the unauthorized use prevention system activation setting process is ended (S205), and thereafter, the normal operation is started.

Fig. 4 is an operation sequence diagram showing an operation process of the abuse prevention system that operates immediately after the power is turned on. In fig. 4, when the projection type image display apparatus 101 is powered on, the CPU102 starts the operation of the unauthorized use prevention system (S401), and first checks whether or not the activation of the unauthorized use prevention system is set (turned on), and checks the state of the unauthorized use prevention system activation setting stored in the memory 103 (S402). If the start-up of the unauthorized use prevention system is not set in S402, the process proceeds to S410, and the apparatus is operated normally as it is. If the start-up of the improper use prevention system is set in S402, the angle sensor 108 detects the installation angle α indicating the use state, that is, the installation posture (S403), and compares the detected installation angle (hereinafter, referred to as "detected angle") with the installation angle α registered in the memory 103 (S404). In this case, in consideration of the accuracy of the angle sensor 108, it is also possible to allow a detection error of the angle sensor, for example, a difference (margin) of about ± 2 degrees, to exist in the comparison between the detected angle and the registered set angle. If the detected angle is compared with the registered installation angle and it is determined that the detected angle is equal to or within the error range, it is considered that there is no change in the use state (installation posture in this case) and theft has not occurred, the process proceeds to S410, normal operation is started as it is, and the operation process of the improper use prevention system is terminated (S411). If the detected angle is different from the registered set angle in S404, since the theft is estimated to have occurred, normal operations other than the power-off operation are prohibited in S405, the image processing section 104 displays a password input request screen 501 as shown in fig. 5, prompts the input of a password (S406), and determines in S407 whether or not the input password matches the registered password. Further, it goes without saying that normal operations other than the power-off operation are prohibited until the registered password is input by operating the button 105 or the remote controller 106. When it is determined in S407 that the input password matches the registered password, the input request password screen 501 is erased (S408), the prohibition of normal operation is released (S409), normal operation is started (S410), and the operation process of the illicit use prevention system is ended (S411). In this case, when an incorrect password is input a predetermined number of times (for example, 5 times), only the input of the password may be prohibited or may not be used at all.

As described above, according to the present embodiment, by detecting a change in the use state (change in the installation posture in the present embodiment), it is possible to estimate unauthorized use by theft and perform authentication check, and if no change is detected, it is determined that there is no unauthorized use by theft. That is, it is possible to realize a system for preventing unauthorized use of a projection type image display device while simplifying the complicated operation of the authentication check and suppressing the deterioration of operability.

In addition, in the projection type image display apparatus, an angle sensor is originally mounted in order to correct projection type image distortion (so-called keystone distortion) or the like caused by the installation angle, and in this case, the angle sensor is also used as a use state detector, and it is not necessary to add a new angle sensor, and thus the cost is not increased.

In addition, in the case where the angle sensor 108 includes a detection axis having two or three axes, the installation angle can be detected and the installation posture can be further limited by installing the angle sensor in parallel to a plane formed by two axes orthogonal to the detection axis and a plane formed by the gravity direction and the projection direction, by which the installation position (base surface installation) and the overhead suspension installation (overhead suspension installation) placed on the floor can be distinguished. For example, in the case where the angle sensor 108 having two-axis angle detection axes shown in fig. 6 is provided, the installation angle can be detected by the detection axis 601 and the detection axis 602 by installing the angle sensor so that the plane formed by the gravity direction 603 and the projection direction 604 of the projection type image display device is parallel to the plane, and the installation on the floor and the overhead suspension installation can be discriminated by the detection axis 602. Here, the above-mentioned installation on the floor is a state where the upper surface of the apparatus is installed upward. The overhead suspension installation is a state in which the apparatus is installed in a vertically inverted manner, and is an installation method that can be seen in a case where the apparatus 101 is mounted on a ceiling 702 by a fixture (overhead suspension installation fixture) 701, for example, as shown in fig. 7.

In addition to the unauthorized use prevention system described in the present embodiment, for example, as shown in fig. 8, if a mark 801 for warning that normal operation is prohibited when the installation state is improperly changed is attached to a portion that is easily visible on the housing of the projection type image display apparatus 101, it is possible to make surrounding people know that the unauthorized use prevention system is activated, and thus it is possible to more effectively suppress theft.

Fig. 9 is a block diagram showing a projection type image display apparatus according to a second embodiment. In the first embodiment, the theft is estimated by using the change in the installation posture, but in the second embodiment, as shown in fig. 9, the installation direction as one form of the usage state is detected by a geomagnetic sensor 901 instead of the angle sensor 108 (see table 1), and the theft is estimated by using the change in the installation direction. Other aspects of the present embodiment are the same as those of the first embodiment, and a description thereof will be omitted here.

Next, we describe the third embodiment. Fig. 10 is a block diagram showing a projection type image display apparatus according to a third embodiment. In the first embodiment, the theft is estimated by using the change in the installation posture, but in the third embodiment, as shown in fig. 10, the projection distance or the distance to the wall surface is detected by a distance measuring sensor 1001 instead of the angle sensor 108, and the change in the installation place (see table 1) which is one form of the usage state is read from the detected change in the distance, and the theft is estimated. Other aspects of the present embodiment are the same as those of the first embodiment, and a description thereof will be omitted here.

Next, we describe the fourth embodiment. Fig. 11 is a block diagram showing a projection type image display apparatus according to a fourth embodiment. In the first embodiment, the theft is estimated by using the change in the installation posture, but in the fourth embodiment, as shown in fig. 11, the CPU102 detects the scenery around the apparatus by the monitor camera 1101 without using the angle sensor 108, reads the change in the installation location from the detected change in the scenery around the apparatus, and predicts the theft. As an example of detecting a landscape around the apparatus, for example, as shown in fig. 12, there is a method in which a monitor camera 1101 is provided on the side of the projection lens, a landscape 1201 in the projection direction is detected and registered as a surrounding landscape, and when a landscape other than the registered landscape is detected, the normal operation of the apparatus is prohibited.

The theft is estimated from a change in the installation posture by the angle sensor 108 in the first embodiment, but the angle sensor 108 is not used in fig. 1 in the fifth embodiment. In the present embodiment, the CPU102 detects a change in a signal input from the input terminal 111 by the input signal processing I/F110, reads a change in the input state of the input terminal from the detected change in the signal, and estimates theft. Examples of the method of detecting a change in an input signal include a method of registering a state in which signals of XDA and 85Hz are input to RGB signal input terminals, and inhibiting normal operation of the apparatus when an input of a signal other than the registered signal is detected.

Next, we describe the sixth embodiment. Fig. 13 is a block diagram showing a projection type image display apparatus according to a sixth embodiment. In the first embodiment, the theft is estimated by using the change in the installation posture, but in the sixth embodiment, as shown in fig. 13, the insertion of the connector or plug 1301 into the input terminal 111 is detected without using the angle sensor 108, and the theft is estimated by reading the change in the input state of the input terminal from the presence or absence of the insertion of the connector or plug 1301. Examples of the method of detecting the presence or absence of the insertion of the connector or the plug into the input terminal include a method of detecting the presence or absence of the insertion of the RCA plug by using an RCA socket with a switch attached to the input terminal, registering a state with the insertion, and inhibiting normal operation of the apparatus when the absence of the insertion is detected.

Next, we describe a seventh embodiment. Fig. 14 is a block diagram showing a projection type image display apparatus according to a seventh embodiment. Fig. 15 is a diagram showing a fixed state of the projection type image display apparatus. In fig. 14, elements having the same functions as those in fig. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

This embodiment can be suitably applied to a case where the projection type image display apparatus 101 is fixed to, for example, a ceiling 702 or the like by a fixing metal tool (overhead hanging metal tool) 701 or the like as shown in fig. 7. In this embodiment, as shown in fig. 14 and 15, theft is estimated by reading (sensing) a change in the fixing state from the presence or absence of fixing of the device to a fixture (here, a ceiling) detected by a fixing screw 1401 and a switch 1402.

In the first to seventh embodiments, the theft is predicted by using the changes in the installation state shown in table 1, that is, (1) the installation posture, (2) the installation direction, (3) the installation location, (4) the input state to the input terminal, and (5) the change in the fixed state, but in the eighth embodiment, the theft is predicted by using the change in the installation state of the device. Fig. 16 is a block diagram showing a projection type image display apparatus according to an eighth embodiment. In fig. 16, elements having the same functions as those in fig. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

In the present embodiment, as shown in fig. 16, the position of the projection lens 1601 of the projection optical unit 112 is detected by a potentiometer 1602, and a change in the focus/zoom setting state is read from the detected change in the position of the projection lens, and an improper use due to theft or the like is estimated.

Next, we describe a ninth embodiment. In this embodiment, instead of estimating theft by using a change in zoom/focus setting state of the lens detected by the potentiometer of the eighth embodiment, a correction value for distortion (so-called keystone distortion) of a projected image is used. Distortion is generated in the projected image due to the setting posture of the apparatus and the distance to the screen. To correct the distortion, distortion correction processing is generally performed on the projected image data. In the present embodiment, the CPU102 that records the parameters of the distortion correction process in the memory and records them compares the projection image distortion (so-called keystone distortion) correction value that was last set by the apparatus user and recorded in the memory 103 with the projection image distortion correction value registered in advance by a legitimate user, reads the change in the projection image distortion correction value, and estimates improper use due to theft or the like. The hardware configuration in this case is a configuration excluding the angle sensor 108 in fig. 1. However, as shown in fig. 25, the nonvolatile memory 103 has a configuration in which a storage area for storing the correction value 1 generated by the authorized user registered in the system activation setting process of fig. 2 and a storage area for storing the correction value 2 changed in the other normal process are provided separately.

In the case of the present embodiment, since the correction value 2 corrected in the device activation is used to detect improper use, improper use up to one time may be permitted. For example, in the case of an unauthorized prevention system without a password and in the case of unauthorized release of a lock generated by a password, unauthorized use may occur. In the case of improper use, the distortion correction value of the projected image needs to be changed because the installation location and the installation position are different. In this case, the changed value is stored as the correction value 2 in the nonvolatile memory 103. That is, when there is a request to change the correction value, it is determined whether the correction data is in the system start-up setting process of fig. 2 or in the normal process, and the correction data is stored in correction value 1 in the system start-up setting process and the correction data is stored in correction value 2 in the normal process. When the next start-up is performed, the stored correction value 2 is compared with the correction value 1 from the authorized user, and whether or not the correction value is used improperly is determined based on whether or not the stored correction value is matched with the correction value 1.

The correction value may be compared at a predetermined timing not only when the apparatus is powered on. Alternatively, the following structure may be formed: when the device power supply is required to be cut off as a trigger, the power supply is cut off under the condition that a correct code is not input for a predetermined number of times and a correct code is different from a correct code 1 and a correct code 2, and then the next device is prohibited from starting. In this case, the nonvolatile memory 103 is configured to have a flag for prohibiting activation of the apparatus, and to perform a process of setting up the flag when the power is turned off. When the device is in the unauthorized use prevention system activation state, the activation processing of the device is performed after checking the device activation prohibition flag when the device is activated.

In the case of the above-described processing, when the system of fig. 2 is started up when the device is powered on, even if the setting is changed by an authorized user, the password must be requested in fig. 4 when the device is started up next time. It is therefore desirable to start up the system of figure 2 immediately before power shut down is required. Accordingly, when there is a request for turning off the power supply, a pop-up display (pop-up menu) for proposing the start of the system can be displayed on the screen. Alternatively, a configuration may be adopted in which a password is required to be input when the setting is changed.

Further, although fig. 25 is configured to store the first correction value input by the authorized user and the second correction value changed during the normal processing in the memory 103 and to detect the change in the correction value by comparing the first correction value and the second correction value, a configuration may be employed in which one storage area for the correction value is stored in the memory 103 and a flag indicating that there is a change is stored. At this time, the CPU102 detects the presence of a change by checking a flag at a predetermined timing such as when the apparatus is started or when the power is turned off, and restricts the use of the apparatus. Further, in the first embodiment, when theft is estimated from a change in the use state of the apparatus, normal operations other than power-off are prohibited, but in this embodiment, an operation of changing the projected image correction value may be prohibited.

In the tenth embodiment, the CPU102 compares the state of the projection image inversion setting (so-called mirror setting) last set by the apparatus user recorded in the memory 103 with the state of the projection image inversion setting registered in advance by a legitimate user, reads the change in the projection image inversion setting, and estimates an improper use due to theft or the like. The case of the present embodiment registers the setting state 1 registered by a regular user and the setting state 2 implemented in a normal state by a regular user or an irregular user according to the process of fig. 2 in different storage areas of the nonvolatile memory 103, respectively. Further, at least 1 improper use may be permitted, as in example 9. At this time, the set projection image inversion setting state 2 and the setting state 1 are compared, and the improper use is detected based on whether the setting contents match. The timing of comparison is not limited to the time of power-on, as in example 9. In the first embodiment, when the change in the use state of the reading apparatus is estimated to be stolen, the normal operation other than the power-off is prohibited, but in the present embodiment, the operation of changing the projected image inversion setting may be prohibited.

Although the first to tenth embodiments have been described above, the lens may be arbitrarily combined in the (1) focus/zoom adjustment state, (2) projection image distortion correction value, and (3) projection image inversion setting state, which are described as the setting states of the apparatus in the first to tenth embodiments, (1) setting posture, (2) setting direction, (3) setting position, (4-1) signal input to the input terminal, (4-2) presence/absence of insertion of a plug or a connector into the input terminal, (5) presence/absence of fixing of the apparatus to the holder, and in the eighth to tenth embodiments, which are described as the setting states of the apparatus. By arbitrarily combining these, the estimation accuracy of estimating unauthorized use due to theft or the like can be further improved.

In the following, we describe the eleventh embodiment. By providing the function of transmitting the unauthorized use prevention system release signal to the remote controller 106, the user authentication using the password in embodiment 1 can be performed using the remote controller release signal.

As shown in fig. 17, when the use state detected at the time of device startup differs from the registered use state, CPU102 displays screen 1701 for requesting pressing of the release button of the remote controller described above, and prohibits normal operations other than the power-off operation until receiving a system release signal from the remote controller. Upon receiving the system release signal, screen 1701 requesting release of the button is erased, and normal operation is enabled. The device and the remote controller are managed in different places by a legitimate user, the remote controller is prevented from being stolen together with the device, the release button of the remote controller can be provided with the same effect as the password, and the same effect as the first embodiment can be obtained even in this embodiment.

In the first embodiment, when the use state detected at the time of startup of the projection type image display apparatus is different from the registered use state, the normal operation of the apparatus is prohibited, but is not limited thereto. In this case, the device may be abnormally operated in order to prevent the device from operating normally. For example, as shown in fig. 18, a reversed screen 1801 subjected to vertical reversal processing may be displayed constantly, a scrambled screen 1901 subjected to scrambling processing as shown in fig. 19 may be displayed, or a blank screen 2001 as shown in fig. 20 may be displayed constantly. As shown in fig. 21 and 22, the projection type image display apparatus may be provided with an audio signal generating unit 2101, an amplifier 2102, and a built-in speaker 2103 to generate an alarm.

In the following, we describe the eleventh embodiment. In this embodiment, instead of the mark 801 of fig. 8 described at the end of the first embodiment, as shown in fig. 23, an LED2301 is provided, and as shown in fig. 24, the LED2301 is provided on a portion of the housing of the image display device 201 that is easy to see, and when the improper use prevention system is activated, the LED2301 is turned on or off, whereby surrounding persons can be made aware that the improper use prevention system is activated, and theft can be more effectively suppressed.

Claims

1. A projection type image display apparatus provided with an unauthorized use prevention system, characterized in that: it comprises the following steps:

a memory for storing first information indicating a normal use state of the projection type image display apparatus;

a detector for detecting a use state of the projection type image display apparatus at a predetermined timing; and

a processor for restricting the use of the projection type image display apparatus when the use state detected by the detector is different from the use state indicated by the first information,

the use state detected by the detector is an installation state or a setting state of the projection type image display apparatus, and the use state indicated by the first information is a normal installation state or a normal setting state of the projection type image display apparatus.

2. A projection type image display apparatus equipped with a misuse prevention system according to claim 1, wherein: it further comprises an input device for inputting a password; wherein,

the usage restriction is released when the processor enters a regular password.

3. A projection type image display apparatus equipped with a misuse prevention system according to claim 1, wherein: wherein,

the memory is a non-volatile memory;

the predetermined timing is a time when the projection type image display apparatus is powered on;

the processor inhibits activation of the projection type image display apparatus as a limitation of use.

4. A projection type image display apparatus equipped with a misuse prevention system according to claim 1, wherein: wherein,

the predetermined timing is a time when the projection type image display apparatus is required to be powered off;

the processor inhibits the next start-up of the projection type image display apparatus.

5. A projection type image display apparatus equipped with a misuse prevention system according to claim 4, wherein: wherein,

the memory is a nonvolatile memory having an area for storing control information indicating whether or not to prohibit power-on to the projection type image display apparatus;

the processor determines whether to perform a startup process based on the control information when a next request to turn on the power to the projection type image display apparatus is made.

6. A projection type image display apparatus equipped with a misuse prevention system as described in claim 1, further comprising:

and an alarm for displaying an alarm to restrict the use of the projection type image display apparatus when the use state detected by the detector is different from the use state indicated by the first information.

7. A projection type image display apparatus equipped with a misuse prevention system according to claim 1, wherein: wherein,

the processor stores the first information in the memory in a start process of the illicit use prevention system.

8. The projection type image display apparatus equipped with the abuse prevention system according to claim 7,

the processor stores second information indicating the use state detected by the detector in the memory during normal use of the illicit use prevention system.

9. A projection type image display apparatus provided with an unauthorized use prevention system, comprising:

a memory that stores a first setting value of a specific function of the projection type image display apparatus at a first timing and stores a second setting value of the specific function of the projection type image display apparatus at a timing different from the first timing; and

and a processor for restricting the use of the projection type image display apparatus when the first setting value and the second setting value are detected to be different.

10. A projection type image display apparatus equipped with a misuse prevention system according to claim 9, wherein: wherein

The first timing is a start timing of the illicit use prevention system.

11. A projection type image display apparatus equipped with a misuse prevention system according to claim 9, wherein: wherein,

the processor is used for requiring to input a password when the first set value and the second set value are detected to be different;

the use restriction is released when the inputted password is regular.

12. A projection type image display apparatus equipped with a misuse prevention system according to claim 9, wherein: wherein,

the specific function is a projection image distortion correction value.

13. A projection type image display apparatus equipped with a misuse prevention system according to claim 9, wherein: wherein,

the specific function is a projection image inversion setting state.

14. A projection type image display apparatus equipped with a misuse prevention system according to claim 9, wherein: wherein,

the memory is a non-volatile memory;

the processor detects that the first setting value is different from the second setting value by comparing the contents of the memory.

15. A projection type image display apparatus equipped with a misuse prevention system according to claim 9, wherein: wherein,

the memory has a first storage area for storing a first setting value of a specific function of the projection type image display device as a regular value and a second storage area for storing a second setting value when the projection type image display device is normally operated;

the processor compares a first set value in the first storage area with a second set value in the second storage area, and detects that the first set value is different from the second set value when the first set value and the second set value are not the same.

16. A projection type image display apparatus equipped with a misuse prevention system according to claim 15, wherein: wherein,

implementing the first storage area and the second storage area in a non-volatile memory;

the processor compares when the projection type image display apparatus is powered on.

17. A projection type image display apparatus equipped with a misuse prevention system according to claim 15, wherein: wherein,

the processor compares the first set value and the second set value when a request for turning off the power supply of the projection type image display apparatus is made, and detects the start-up processing for prohibiting the next power-on when the first set value and the second set value do not match.