KR0137591B1 - Apparatus for automatically controlling intensity of radiation of projector - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic light intensity control apparatus of a projection image display device. In particular, an automatic light intensity of a projection image display device in which a strip optical sensor is installed on a stop disk and an optical sensor is also installed outside the projector. It relates to a control device.

It is an object of the present invention to provide an automatic light amount control apparatus of a projection image display device in which the amount of light to be projected is automatically adjusted according to the amount of external light.

The automatic light intensity control apparatus of the projection image display apparatus of the present invention is provided with a strip type optical sensor 16 on a predetermined front surface of a stop in the optical system of the projection image display apparatus, and is external to the projection image display apparatus. An optical sensor 20 is also installed, and a microcomputer for controlling the intensity of the projection light by comparing the amounts of light measured by the two optical sensors 16 and 20 is installed at a predetermined portion.

Description

Automatic Light Control of Projection Image Display

1 is a schematic diagram showing an optical system of a projection image display device according to the present invention;

2 is a schematic view showing a stop and strip type optical sensor according to the present invention;

3 is a schematic diagram showing the operation of the automatic light intensity control apparatus of the projection image display apparatus according to the present invention;

4 is a flowchart illustrating the operation of the automatic light amount control device of the projection image display device according to the present invention.

Explanation of symbols on main parts of drawing

10: screen, 12: projection lens,

14: stop, 16: strip type optical sensor,

18: light source, 20: reflective mirror,

22: field lens 29: optical path controller

30: projection light detection unit 32: external light detection unit

34: micom 36: projection light control unit

40: external light sensor 50: projection image display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic light intensity control apparatus of a projection image display device. In particular, a projection image display device in which a strip optical sensor is installed on a stop disk and an optical sensor is also installed outside the projection image display device. It relates to an automatic light control device of.

An image display apparatus is classified into a direct image display apparatus and a projection image display apparatus according to a display method.

The direct view type image display apparatus includes a CRT (Cathode Ray Tube). The CRT image display apparatus has a good image quality but has a problem such as an increase in weight and thickness as the screen is enlarged, and a high price. There is a limit.

Projection type image display devices include a large crystal display (hereinafter referred to as an LCD), and such a large screen LCD can be thinned to reduce the weight. However, the LCD has a high light loss due to the polarizing plate, and a thin film transistor for driving the LCD is formed for each pixel, so that there is a limit in increasing the aperture ratio (light transmission area).

Accordingly, a projection image display device using Actuated Mirror Arrays (hereinafter referred to as AMA) has been developed by Aura, USA.

The projection image display device is divided into one-dimensional AMA and two-dimensional AMA. The one-dimensional AMA has mirror surfaces arranged in an M × 1 array, and the two-dimensional AMA has mirror surfaces arranged in an M × N array. Therefore, a projection image display device using a 1D AMA pre-scans M x 1 rays using a scanning mirror, and a projection image display device using a 2D AMA projects M x N luminous fluxes to form an array of M x N pixels. Branches represent images.

In general, in a projection image display device, the amount of light emitted from a light source is constant. Therefore, there is a problem in that the amount of projection of the projection image display device cannot be adjusted as the amount of external light in a room or living room changes.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic light amount control apparatus for a projection image display device in which the amount of light projected is automatically adjusted according to the amount of external light.

In order to achieve the above object, the automatic light intensity control apparatus of the projection image display apparatus of the present invention installs a strip type optical sensor on a predetermined front surface of a stop in the optical system of the projection image display apparatus, An optical sensor is installed outside the image display device, and a microcomputer for comparing the amounts of light measured by the two sensors is installed at a predetermined portion.

1 is a schematic view showing an optical system inside the projection image display apparatus according to the present invention. As shown in this figure, the projection image display apparatus 50 includes a projection lens 12, a light source 18, a stop 14, It is composed of a reflecting mirror 20, a field lens 22, an optical path controller 29.

The light source 18 emits high brightness white light. Reflective mirror 20 is installed at an angle so as to have a predetermined direction, for example, 40 ° ~ 50 ° of the white light forming a predetermined shape through the light source 18, the primary light flux at a predetermined angle, the x-axis, For example, 80 ° to 100 ° is bent and reflected by the field lens 22.

The optical path controller 28 includes a mirror 26 which reflects incident light on the driving substrates 27 so as to adjust the path of the light corresponding to the pixels, and the actuator 25 which causes the mirror 26 to have an inclination is M. The actuator array panel 28 in which x N pieces are mounted is comprised. The driver substrate 27 includes M x N transistors (not shown), and the actuator 25 is mounted on the driver substrate 27 to be electrically connected to the transistors, and is driven by an electric field generated by an image signal. It is deformed to tilt the mirrors 26 mounted thereon. The actuator 25 is formed of a piezoelectric or electrodistoric ceramic of a thin film and is deformed by an electric field generated by an image signal applied from an external circuit (not shown) through transistors and pads. 26) and be inclined 85 to 88 ° with respect to the y-axis. In addition, the mirror 26 is mounted on the actuator 28 and inclined by the driving of the actuator 25. The actuator 25 and the mirror 26 correspond to the pixels, and the light incident from the field lens 22 corresponds to each pixel by the mirror 26 and adjusts and reflects the light path. When the actuator 25 is not driven in the above manner, one side edge of the light formed in the stop 14 does not pass through the light transmitting area while being coincided with the other edge of the light transmitting area. However, when driven, only the light of the corresponding color is allowed to pass through the light transmission area of the stop 14 in proportion to the inclination angle to adjust the density of the light. In order for the color light corresponding to any same pixel to be illuminated by the same image signal, the movement distance of the light between the reflection mirror 20 and the actuator 28 is the same. If the image signal is not applied to the optical path controller 29 and the actuator 28 is not driven, the axis of reflected light is reflected at an angle of 85 to 88 ° with respect to the mirror 26 and the y axis.

The field lens 22 may be positioned in front of the actuator array panel 28 to have a large reflection angle so that the light reflected from the mirror 26 is not lost and the light path is reduced. The projection lens 12 passes through the light transmission area of the stop 14 to project the light whose light amount is adjusted to the screen 10.

On the other hand, a strip type optical sensor 16 is provided at a predetermined front surface of the stop 14 so as to detect light that has not transmitted through the screen 20 as an electrical signal. In addition, an external light sensor 40 is provided on the side or the rear of the outside of the projection image display device 50 to detect external light as an electrical signal (see FIG. 3).

Electrical signals corresponding to the amounts of light measured by the sensors 16 and 40 are converted into digital signals by the projection light detector 30 and the external light detector 32, respectively, to micom (not shown). Are entered and compared.

4 is a flowchart illustrating the operation of the automatic light amount control device according to the present invention. As shown in the drawing, a predetermined electrical signal corresponding to the amount of light detected by the strip type sensor 16 is input to the projection light detecting unit 30. And converted into a predetermined digital signal and input to the microcomputer 34, and a predetermined electrical signal corresponding to the amount of light detected by the external light sensor 40 is input to the external light sensing unit 32 and converted into a predetermined digital signal. The conversion is also input to the microcomputer 30. The microcomputer 34 has a predetermined comparison data, and compares the signals input from the two sensors to output a comparison signal, and the comparison signal output from the microcomputer 34 is transmitted to the projection light control unit 36. A predetermined electrical signal is input and output to the light source 18 so that the projection light is automatically adjusted from the projection image display device 50.

In the operation of the automatic light amount control device of the projection image display device installed as described above, in order to automatically adjust the light quantity, first, the projection image display device 50 is set to the automatic adjustment mode, and the operation switch of the projection image display device 50 is used. When (not shown) is turned ON, the screen changes to the automatic adjustment mode (in this case, white is displayed on the screen). The light source 18 emits high-intensity white light, and the emitted light is reflected by the reflection mirror 20 at a predetermined angle and focused by the field lens 22 to focus on the actuator panel 28. The light path is adjusted and reflected by the panel 28. At this time, if the actuator 25 is not driven, the reflected light is reflected at the same angle as the incident angle. However, when the actuator 25 is driven due to an image signal being applied, the angle of the reflected light is increased. As a result, when the inclination angle of the mirror 26 on the upper portion of the actuator 25 becomes maximum, the reflected light becomes perpendicular to the actuator panel 28. Then, the light reflected from the actuator panel 28 is focused again by the field lens 22 and proceeds to the stop 14. When each actuator 28 is not driven, it is imaged on top of the stop 14, and when driven, it passes through the hole of the stop 14 in proportion to the inclination angle of the actuator 28.

On the other hand, in the strip type optical sensor 16 installed at a predetermined front surface of the stop 14, light that does not penetrate the light transmitting area of the stop 14 is detected, and an electrical signal corresponding thereto is detected. The external light sensor 40 installed on the external side or the rear of the image display device 50 outputs a predetermined electrical signal corresponding to the detected amount of external light. The strip-type light sensor 16 and the external light sensor are output. The electrical signal of 40 is input to the microcomputer 34 as a predetermined digital signal through the projection light sensing unit 30 and the external light sensing unit 32, respectively, and the two signals are compared in the microcomputer 34. The comparison signal is inputted to the projection light control unit 36, and a predetermined electrical signal from the projection light control unit 36 is to automatically adjust the intensity of the light source 18.

In the above description, the larger the amount of light detected by the strip type optical sensor 16, the smaller the amount of projection light.

As described above, the automatic light amount control apparatus of the projection image display apparatus of the present invention has an effect that the amount of light to be projected is automatically adjusted according to the amount of external light.

Claims (1)

A light source 18 emitting high brightness white light, a reflection mirror 20 that reflects the emitted white light at a predetermined angle, and an optical path controller reflecting the reflected light by adjusting the light paths for each unit pixel by reflecting the reflected light at a predetermined angle ( 27), a stop 14 for passing the color light in which the optical path is adjusted and the color light is proportional to the degree adjusted through the hole; and the stop 14 without losing the light reflected from the optical path controller 27. A projection image display device (50) having a field lens (22) for forming an image and a projection lens (12) for projecting color light passed through the hole onto a screen (10), wherein the front surface of the stop (12) is provided. A strip type optical sensor 16 provided at a predetermined portion and an external light sensor 40 provided at an outer side or rear side of the projection image display device 50 are provided. The strip type optical sensor 16 is provided. ) And a predetermined electrical signal output by the external light sensor 20 Converts the signal into a digital signal and inputs it to the microcomputer 34 to adjust the intensity of the light source 18 by receiving the signal compared with the projection light detector 30 and the external light detector 32 and the microcomputer 34. And a projection light control unit (36) for generating an electrical signal.