JPH04163584A - Projection type image display device - Google Patents

Abstract

PURPOSE:To minimize the reduction in the brightness of an image and the degradation of white balance even when a display device is used for a long time, so as to display appropriate image by transmitting information correspondent to the integrated result of the lighting hours through a control means, and by carrying out at least one operation of turning power source OFF. CONSTITUTION:When the output result of a lighting hours integrating counter 12 is not more than a first fixed integrated time T1, a switch 11 of a control circuit 13 is kept under an ON condition, and an image is displayed on a screen 9. When the output result of the integration of the lighting hours integrating counter 12 exceeds T1, and when it is not more than a second fixed integrated time T2, an on-screen circuit 14 is controlled by a control circuit 13, while it is displayed on the screen 9 by a MIX circuit 15 that a light source 5 is not used at an appropriate accuracy or at an appropriate white balance, so as to press a user to replace the light source 5. The reduction in the brightness of an image or the degradation of white balanace can thus be minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a projection type image display device that enlarges and projects an image formed in an image forming section onto a screen.

Conventional technology In recent years, projection-type image display devices have been able to produce large-screen images with compact and lightweight systems. projector
is becoming popular even in ordinary households.

An example of the conventional projection type image display device mentioned above will be described below with reference to the drawings.

FIG. 4 is a block diagram of a projection type image display device using a conventional liquid crystal as a display element.

In FIG. 4, 1 is a projection type image display device, 2 is an external power source, 3 is a drive circuit, 4 is a lighting circuit, 5 is a light source, 6 is a condensing optical device, 7 is a liquid crystal panel, 8 is a projection lens, 9 is a screen installed outside.

Regarding the projection type image display device configured as above,
The operation will be explained below.

The drive circuit 3 and lighting circuit 4 supplied with voltage by the external power supply 2 form an image on the liquid crystal panel 7 according to the input video signal voltage, and emit light by lighting the light tA5. The light emitted from the light source 5 is converted into parallel light by the condensing optical device 6 and is irradiated onto the liquid crystal baffle 7. The irradiation light passes through the image on the liquid crystal panel 7 to form an optical image, which is enlarged and projected onto the screen 9 by the projection lens 8 .

Problems to be Solved by the Invention However, when the above configuration is used for a long time, the brightness of the image may decrease due to a decrease in the amount of light emitted from the light source 5, and the amount of red light emitted from the light source 5 may decrease. Since the degree of reduction in the amount of green light and the amount of blue light differs, there is a problem in that the white balance of the image is disrupted, causing deterioration in image quality.

The present invention has been made in view of the above-mentioned problems, and provides a projection type image display device that displays an appropriate image while minimizing reduction in image brightness and disruption of white balance even when used for a long time.

Means for Solving the Problems In order to solve the above-mentioned problems, a projection type image display device of the present invention is provided with a lighting time integration means, a control means, an information transmission means, and a switch for controlling a power source. The means is characterized in that the means performs at least one of the following operations: controlling the information transmitting means to transmit information or controlling the switch to turn off the power supply according to the cumulative result of the lighting time cumulative means. That is.

Effect of the Invention The present invention has the above-described configuration, and is a projection type that not only informs the user of the usage time of the light source but also turns off the power when the light source is used for a long period of time, thereby minimizing reduction in image brightness and disruption of white balance. It becomes possible to provide an image display device.

EXAMPLE Hereinafter, a projection type image display device according to an example of the present invention will be described with reference to a concave surface.

FIG. 1 is a block diagram of a projection type image display device according to a first embodiment of the present invention. In FIG. 1, ■ is a projection type image display device, 2 is an external power supply, 3 is a drive circuit, 4 is a lighting circuit, 5 is a light source, 6 is a condensing optical device, 7 is a liquid crystal panel, 8 is a projection lens, 9 is a screen installed outside, 11 is a switch, 12 is a lighting time integration counter, 13 is a control circuit, 14 is an on-screen circuit, and 15 is a MIX circuit. Note that the MIχ circuit is a circuit that mixes the video signal voltage output from the drive circuit 3 and the information signal voltage output from the on-screen circuit 14, and displays information in a superimposed manner on the video on the screen 9.

Regarding the projection type image display device configured as above,
The operation will be explained below.

First, if the output result of the lighting time integration counter 12 is less than or equal to the first predetermined integration time (hereinafter referred to as T1),
The control circuit 13 keeps the switch 11 in the on state and does not drive the on-screen circuit 14, and an image is displayed on the screen 9 by the same operation as in the conventional example described above.

Next, if the output result of the lighting time integration counter 12 is an integration time exceeding T1 and a second predetermined integration time (hereinafter referred to as T
(denoted as 2, T2>T) or below, the control circuit 13 controls the on-screen circuit 14 based on the detection result of the lighting time integration counter 12, and outputs the light onto the screen 9 through the MIX circuit 15. It is displayed that the light a5 is not being used with proper brightness or proper white balance, and the user is prompted to replace the light source 5.

At this time, if the user replaces the light tA5, the projection type image display device 1 again displays an appropriate display, and the lighting time integration counter 12 starts counting the lighting time from O again. but,
If the user does not replace the light source 5, the lighting time accumulation counter 12
If the output result is used for an integrated time exceeding T2, the control circuit 13 turns off the switch 11 to extinguish the light tX5. By the above operation,
It is possible to provide a projection type image display device that minimizes reduction in image brightness and disruption of white balance even when the light fI5 is used for a long time.

A projection type image display device according to a second embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows the configuration of a projection type image display device according to a second embodiment of the present invention. In FIG. 2, 21 is an LED.

First, if the output result of the lighting time integration counter 12 is less than or equal to the first predetermined integration time T1 described above, the control circuit 13 keeps the switch 11 in the on state and does not drive the LED 21, as in the conventional example. Screen 9
The image is displayed above.

Next, if the output result of the lighting time integration counter 12 is an integration time exceeding T1 and the lighting time is used for less than the second predetermined integration time T2, the control circuit 13 controls the LED 21 to emit light, indicating that the projection type image display device 1 is not being used with proper brightness or proper white balance, and prompting the user to replace the light source 5. At this time, if the user replaces the light source 5, the projection type image display device 1 again performs proper display, and the lighting time integration counter 12 starts counting the lighting time from O again.

However, if the user does not replace the light fi 5 and the output result of the lighting time integration counter 12 exceeds T2, the control circuit 13 turns off the switch 11 to turn off the light source 5. Turn off the lights. By the above-described operation, it is possible to provide a projection type image display device that minimizes reduction in image brightness and disruption of white balance even when the light source 5 is used for a long time.

Note that in this example, the configuration using LEDs was explained, but
In addition to LEDs, other light emitting elements may be used.

Further, although a light emitting element is used in this embodiment, it may be displayed using characters or the like on the projection type image display device 1.

A projection type image display device according to a third embodiment of the present invention will be described below with reference to the drawings.

In FIG. 3, 31 is a speaker. First, if the output result of the lighting time integration counter 12 is less than or equal to the first predetermined integration time T1, the control circuit 13 controls the switch 11
An image is displayed on the screen 9 by the same operation as in the conventional example without driving the speaker 31 and keeping it in the on state.

Next, if the output result of the lighting time integration counter 12 is an integration time exceeding T and is used for less than the second predetermined integration time T2, control is performed based on the detection result of the lighting time integration counter 12. The circuit 13 controls the speaker 31 to indicate by sound or the like that the projection type image display device l is not being used with proper brightness or proper white balance, and prompts the user to replace the light source 5.

At this time, if the user replaces the light source 5, the projection type image display device 1 again performs proper display, and the lighting time integration counter 12 starts counting the lighting time from 0 again. but,
If the user does not replace the light source 5, the lighting time accumulation counter 12
If the output result is used for an integrated time exceeding T2, the control circuit 13 turns off the switch 11 to turn off the light source 5. By the above-described operation, it is possible to provide a projection type image display device that minimizes reduction in image brightness and disruption of white balance even when the light a5 is used for a long time.

It goes without saying that even greater effects can be obtained by combining the first, second, and third embodiments described above.

Also, in this example, the external power supply is turned off, but
Only the lighting circuit may be turned off, and the cumulative lighting time of the lamp 5 may be notified on the screen 9 or from the projection image display bag W1 at any time in response to a user's request.

Effects of the Invention As described above, the present invention makes it possible to provide a projection type image display device that minimizes reduction in image brightness and disruption of white balance due to the above-described configuration.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a projection type image display device according to a first embodiment of the present invention, FIG. 2 is a configuration diagram of a projection type image display device according to a second embodiment of the present invention, and FIG. 3 is a configuration diagram of a projection type image display device according to a second embodiment of the present invention. FIG. 4 is a block diagram of a projection type image display apparatus according to the third embodiment of the present invention, and FIG. 4 is a block diagram of a projection type image display apparatus using a conventional liquid crystal as a display element. 2... External power supply, 7... Liquid crystal panel,
11... Sui Nochi, 12... Lighting time integration counter, 14... On-screen circuit, 21... LED, 31... ·speaker. Name of agent: Patent attorney Haruaki Ogata and two others

Claims (3)

[Claims] (1) A projection type image display device, comprising a lighting time integrating means, a control means, an information transmitting means, and a switch for controlling a power supply, the controlling means controlling the lighting time integrating means. A projection type image display device, characterized in that it performs at least one of controlling the information transmitting means to transmit information and controlling the switch to turn off the power supply according to the integration result. (2) The projection type image display device according to claim (1), wherein the information transmitting means transmits the information by at least one of visual means and auditory means. (3) A claim characterized in that the visual means transmits information from a projection type image display device or a screen.
2) The projection type image display device described above.