JPH08251522A - Projection type display device - Google Patents

Abstract

PURPOSE: To display an image without distortion or tilt by detecting a tilt in forward/backward/left/right directions from a tilt detector and using a control section so as to control a drive section thereby expanding/contracting an expansion leg. CONSTITUTION: A tilt detector 1 detects a tilt in each of longitudinal and lateral directions and outputs a voltage in response to the tilt. A control section 2 controls a drive section 3 based on a detection voltage in the longitudinal and lateral directions from the tilt detector 1. Then the drive section 3 drives an expansion leg 4 under the control of the control section 2. The expansion leg 4 expands/contracts its leg based on a drive signal from the drive section 3. In the projector type display device formed as above, the tilt detector 1 detects a tilt in the forward/backward/left/right directions and outputs a detection signal in response to the tilt and the control section 2 controls the drive section 3 to expand/contract the expansion leg 4 based on the detection signal to keep the horizontality of the display device.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection type display device, and more particularly to a device for controlling a posture to maintain an appropriate positional relationship with a screen.

[0002]

2. Description of the Related Art In a projection display device such as a liquid crystal projector, as shown in FIG. 6, a screen surface, a lens surface, a liquid crystal surface and the like are kept in parallel so that a correct image without distortion is projected on the screen. I am trying. Therefore,
If the degree of parallelism with the screen surface is lost, there is a problem that the image is distorted or tilted as shown in FIG. 5 and a correct image cannot be obtained. Therefore, in the conventional projection display device, the operator corrects the distortion or the inclination by looking at the screen and correcting the posture of the device, or by visually looking at the leveler provided in the device. . However, in this method, it takes a lot of time to correctly correct the posture of the apparatus, so that it is necessary to provide a preparation time in advance.

[0003]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems and automatically corrects the posture of the apparatus,
An object of the present invention is to provide a projection display device capable of displaying an image without distortion or tilt.

[0004]

In order to solve the above-mentioned problems, the present invention is directed to a projection type display device in which a video circuit, a projection optical system for projecting video light, etc. are housed in a housing, and a signal proportional to the degree of inclination is provided. A tilt detector that outputs a signal, a controller that controls the drive unit based on the tilt detection signal, and a plurality of telescopic legs that are driven by the drive unit and that extend and contract in length are provided in the lower portion of the housing. , The attitude of the projection display device is controlled. In addition, the telescopic legs are equipped with a motor, and the rotational force of the motor is expanded and contracted through a gear box, or the pump is provided and the legs are expanded and contracted by hydraulic pressure. . Further, the inclination detector stores a sphere movably inside a rectangular box, and arranges a pressure sensor on the opposite surface of the rectangular box to detect the gravity component of the sphere. Or, divide the inner surface of the mortar,
A plurality of electrodes concentric with the mortar circle in each part, a reference electrode is formed in the lower part of the mortar-shaped body, a voltage is applied via a resistor between the reference electrode and the plurality of electrodes, and the mortar It is characterized in that a conductive liquid material is enclosed in the material.

[0005]

With the above construction, in the projection display device of the present invention, the tilt detector detects the tilts in the front-rear direction and the left-right direction and outputs a detection signal corresponding to the tilts. The control unit controls the drive unit to extend and retract the retractable legs to keep the posture of the apparatus horizontal.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The projection display device according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram of essential parts showing an embodiment of a projection display device according to the present invention. In the figure, reference numeral 1 denotes a tilt detector, which detects a tilt in each of the vertical and horizontal directions and outputs a voltage according to the tilt. A control unit 2 controls the driving unit 3 based on the vertical and horizontal detection voltages detected by the inclination detector 1. The drive unit 3 drives the telescopic leg 4 under the control of the control unit 2.
Reference numeral 4 is the extendable / contractible leg, which extends / contracts the leg portion 41 in response to a drive signal from the drive portion 3. A video input unit 5 inputs a video signal. Reference numeral 6 denotes a video circuit, which is the video input section 5
The processed video signal is input to the liquid crystal panel 7. Reference numeral 7 denotes the liquid crystal panel, which changes the light transmittance according to a signal from the video circuit 6 and sends the video light to the optical system 8. The optical system 8 refracts the image light from the liquid crystal panel 7 and projects it on the screen 10. Reference numeral 9 denotes a housing, which houses the above-mentioned parts, and which has a liquid crystal panel 7 and
The optical system 8 is arranged vertically. The screen 10 projects the image light from the optical system.

FIG. 2 is a perspective view showing an embodiment of the inclination detector 1, FIG. 2-a is a two-way detector, and FIG.
A direction detector is shown. In the figure, 11 is a rectangular box. 12 is a sphere, which is movably stored inside the box 11. Reference numeral 13 is a pressure sensor, and in the case of the two-way detector shown in FIG.
Further, in the case of the four-direction detector shown in FIG. 2B, the four-direction detectors are arranged on four opposite surfaces, and the pressure due to the gravity component of the sphere is converted into electric power and output.

FIG. 3 is a perspective view showing another embodiment of the inclination detector 1. In the figure, reference numeral 15 is a mortar-like body, the inner surface of which is divided into four in the east-west and north-south directions, and the mortar base is used as a reference. A plurality of electrodes 16b are formed concentrically around the electrode 16a, and a voltage is applied between the electrodes 16a and 16b via a resistor 18. 17 is a conductive liquid such as mercury,
When the mortar-shaped body 15 is kept horizontal, the conductive liquid material 17 does not short-circuit between the electrodes 16a and 16b, and no current flows between the electrodes 16a and 16b, but when the mortar-shaped body 15 tilts. The number of electrodes 16b short-circuited by the electrode 16a and the conductive liquid material 17 changes depending on the degree of inclination, and the output detection signal current changes.

FIG. 4 is a block diagram showing an embodiment of the retractable leg 4, FIG. 4-a shows an example using the rotational force of a motor, and FIG. 4-b shows an example using a hydraulic pump. .
In the figure, 41 is a leg, 42 is a motor, 43 is a gear box, 44 is a pump, and 45 is an oil tank. In FIG. 4-a, reference numeral 41 a denotes a motor driving leg portion, which is a columnar body having a plurality of grooves formed in the horizontal direction, and which slides on a cylindrical leg mounting portion provided at the bottom of the housing 9. ing.
Reference numeral 42 denotes the motor, which extends and contracts the leg portion 41a via a gear box 43. 43 is the gear box,
Worm gear 43a connected to the rotating shaft of the motor 42
Rotation of the wheel gear 43c is transmitted to the worm wheel 43b so as to be concentric with the worm wheel 43b.
Presses the groove cut in the leg portion 41a and slides the leg portion 41a to expand and contract. In FIG. 4-b, 4
Reference numeral 1b denotes a hydraulically driven leg, in which a T-shaped body 412 in cross section is slidably arranged inside a cylindrical body 411 having upper and lower openings, and a leg 413 is provided at a lower portion of the T-shaped body 412. Tena,
When the oil 46 is injected from the oil injection port 411a provided in the upper opening, the T-shaped body 412 is pushed down, and when the oil 46 is sucked out, the T-shaped body 412 rises to expand and contract the legs.
A motor 42b drives the pump 44. The pump 44 is driven by the motor 42b to move the oil 46 between the oil tank 45 and the leg portion 41b. The oil tank 45 stores the oil 46. Reference numeral 46 denotes the oil, which is moved between the oil tank and the legs by the pump.

The operation of the above arrangement will be described below. The video signal input to the input unit 5 is processed by the video circuit 6 and input to the liquid crystal panel 7 to change the light transmittance of the liquid crystal, and the image light transmitted through the liquid crystal panel 7 passes through the optical system to the screen 10. The image is projected and the image is displayed on the screen 10. On the other hand, the inclination detection unit 1 detects the vertical and horizontal inclinations of the housing 9 forming the projection display device, and outputs a voltage corresponding to the inclination degree in each direction. For example, if you lean to the left as shown in Figure 2-c,
The sphere inside the box moves to the left by its own weight, pushes the pressure sensitive device 13a provided on the left side, and the pressure sensitive device 13a outputs a voltage according to the pressure. Further, also in the case of the mortar-shaped body inclination detection unit 1 shown in FIG. 3, the detection current corresponding to the inclination is output as described above. A detection signal from the inclination detection unit 1 is input to the control unit 2, and the control unit 2 drives the extendable leg 41 arranged on the left side of the housing to extend and the extendable leg 41 arranged on the right side to contract. It is controlled via the section 3. In this manner, the lengths of the front and rear legs and the left and right legs are controlled so that the housing 9 is horizontal.

[0011]

As described above, according to the projection display device of the present invention, the tilt detector detects the tilts in the front and rear, and the left and right, and outputs a detection signal corresponding to the tilts. Based on this, the control unit controls the drive unit to extend and retract the retractable legs so that the posture of the device is kept horizontal. It is possible to provide a projection display device capable of displaying a non-existent image.

[Brief description of drawings]

FIG. 1 is a principal block diagram showing an embodiment of a projection display device according to the present invention.

FIG. 2 is a perspective view showing an embodiment of an inclination detection unit of the projection display device according to the present invention.

FIG. 3 is a perspective view showing another embodiment of the inclination detection unit of the projection display device according to the present invention.

FIG. 4 is a block diagram showing an embodiment of the extendable legs of the projection display device according to the present invention.

FIG. 5 is a diagram for explaining image distortion and inclination due to the attitude of a conventional projection display device.

FIG. 6 is a diagram illustrating a correct projection method of a conventional projection display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inclination detection part 2 Control part 3 Driving part 4 Telescopic leg 5 Image input part 6 Video circuit 7 Liquid crystal panel 8 Optical system 9 Housing 10 Screen 11 Box body 12 Sphere 13 Pressure sensor 15 Cones 16a Reference electrode 16b Multiple Electrode 18 Resistor 41 Leg 41a Leg 41b Leg 42 Motor 42a Motor 42b Motor 43 Gear Box 43a Worm Gear 43b Worm Wheel 43c Wheel Gear 44 Oil Pump 45 Oil Tank 411 Cylindrical 411a Oil Inlet 411b Tee 4 Opening Body 413 legs

Claims (12)

[Claims] 1. A projection type display device in which a video circuit, a projection optical system for projecting video light, and the like are housed in a housing, and a tilt detector for outputting a signal proportional to a tilt degree, and based on the tilt detection signal. A control unit that controls the drive unit and a plurality of telescopic legs that are driven by the drive unit and that extend and contract in length are provided in the lower portion of the housing to control the attitude of the projection display device. And a projection display device. 2. The projection display device according to claim 1, wherein the tilt detector comprises two bidirectional detectors arranged in two directions at right angles to the horizontal direction. 3. The projection display device according to claim 1, wherein the tilt detector comprises one four-direction detector arranged in a casing. 4. The projection display device according to claim 1, wherein three extendable legs are provided. 5. The projection display device according to claim 1, wherein four extendable legs are provided. 6. The projection display device according to claim 1, wherein the extendable leg includes a motor, and the rotational force of the motor is extended and retracted via a gear box. 7. The projection display device according to claim 1, wherein the retractable leg is provided with a pump, and the leg is extended and retracted by hydraulic pressure. 8. The tilt detector and the telescopic leg are arranged such that at least one longitudinal and lateral direction is aligned with a direction connecting two telescopic legs.
The projection display device according to claim 4 or 5. 9. The two-way detector stores a sphere movably inside a rectangular box, and arranges pressure sensors on both left and right sides of the rectangular box facing each other, and detects the gravity of the sphere. The projection display device according to claim 2, wherein the component force is detected. 10. The two-way detector divides the inner surface of the mortar-shaped body into two parts in the east-west direction, and a plurality of electrodes concentric with the mortar circle in each part and a reference electrode in the lower part of the mortar. The projection according to claim 2, wherein a voltage is applied between the reference electrode and the plurality of electrodes via a resistor to enclose a conductive liquid material in the mortar-shaped body. Type display device. 11. The four-direction detector has a spherical body movably arranged inside a rectangular box body, and pressure sensors are arranged on front, rear, left and right surfaces of the rectangular box body facing each other. The projection display device according to claim 3, wherein the component of gravity of the sphere is detected. 12. The four-way detector divides the inner surface of the mortar-shaped body into four parts in the east-west and north-south directions, and a plurality of electrodes concentric with the mortar circle are provided in each part, and in the lower part of the mortar. 4. A reference electrode is formed, a voltage is applied between the reference electrode and a plurality of electrodes via a resistor, and a conductive liquid material is sealed in the mortar-shaped body. Projection display device.