JP2797406B2 - Projector device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projector device, and more particularly, to a projector device that projects an optical image on a projection surface such as a screen to form an image.

[Summary of the Invention]

The distance between the projector body and the screen is measured from two points on the front side of the projector body, and the correction of the twist angle of the screen of the projector body and the automatic focus adjustment of the projection lens are performed based on the measured distances. And related projector devices.

[Conventional technology]

As shown in FIG. 7, the projector device projects a light image onto a screen 3 from an optical system 2 provided at a front end side of a projector main body 1 and forms an image on the screen 3. is there. In such a projector device, in a separate type projector in which the projector body 1 and the screen 3 are separated and independent from each other, the projector body 1 and the screen 3
In order to move freely with each other, there is a possibility that projection is performed in a state where a twist angle θ is generated as shown in FIG.

As shown in FIG. 7, when the screen 3 is not perpendicular to the optical axis of the projector body 1, image distortion occurs, or the left and right portions on the screen image become out of focus. Therefore, conventionally, as shown in FIG. 8, both ends of the projector main body 1 and the screen 3 are tied with strings 4, and the relative positional relationship between the screen 3 and the projector main body 1 is set so that these strings are taut. Had to be set. By such a measure, both are in an ideal arrangement with each other.

[Problems to be solved by the invention]

However, according to such a conventional method, when the distance between the projector main body 1 and the screen 3 is long, it is difficult to determine the positional relationship between the two by the string 4. Further, as shown in FIG. 9, when the chair 4 of the seat is previously installed between the projector main body 1 and the screen 3, adjustment by the string 4 becomes difficult.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a projector device capable of automatically performing a twist correction on a projection surface of a projector main body.

[Means for solving the problem]

The present invention has a projector main body, two or more sensors, a determination unit, and a twist correction mechanism, and the sensor is disposed near a front surface of the projector main body,
The determining unit obtains information on a twist angle of the projector main body from a difference between output signals of the two or more sensors, and performs a twist correction of the projector main body based on the information.

[Action]

Therefore, the judging unit obtains information on the twist angle of the projector main body from the difference between the output signals of two or more sensors arranged in the vicinity of the front surface of the projector main body, and performs the twist correction of the projector main body based on this information. Will be.

〔Example〕

As shown in FIG. 2, the projector main body 10 has a rectangular parallelepiped cabinet, and a projection lens 11 forming an optical system is attached to the front side of the main body 10. The projection lens 11 can be moved in the optical axis direction by a drawing mechanism 12. The mechanism 12 is driven by a motor 13 shown in FIG. The main body 10 is supported by a base 15 via a rotation mechanism 14. The rotation mechanism 14 is a motor shown in FIG.
16 to be driven.

An ultrasonic transmitter 19 and a sensor 20 including an ultrasonic receiver are arranged on the front side of the projector main body 10 and on the left side thereof. An ultrasonic transmitter 21 and a sensor 22 constituting the ultrasonic receiver are also arranged on the right side. The transmitters 19 and 21 and the sensors 20 and 22 are connected to the projector body 10 and the screen 17.
To measure the distance between them. The ultrasonic transmitters 19 and 21 are connected to pulse transmission circuits 23 and 25, respectively. On the other hand, the sensors 20 and 22 include a pulse receiving circuit 24,
26 is to be connected. And four circuits 23
26 are connected to the control circuit 27. A counter circuit 28 is connected to the control circuit 27, and a reference pulse oscillation circuit is connected to the counter circuit 28.
29 is to be connected.

The counter circuit 28 is connected to a difference detection circuit 30, and the difference detection circuit 30 is connected to a torsion angle calculation circuit 31. And the torsion angle calculation circuit 31
Is connected to a motor drive circuit 32, and the motor 16 is driven by the drive circuit 32 to perform a twist correction operation. The counter circuit 28 is connected to a lens extension calculating circuit 33, and the calculating circuit 33 is connected to a motor driving circuit 34. The motor drive circuit 34 drives the motor 13 to perform an autofocus operation.

Next, the operation of the projector main body 10 according to the above configuration for correcting the torsion will be described. Now projector
It is assumed that the power is turned on at 10 and the mode is set to the torsion correction and focus adjustment mode. Then at time t ₀ shown in FIG. 3, the ultrasonic sensor switching signal, the ultrasonic transmitter 19
And the sensor 20 are activated. Then, a pulse is transmitted from the transmitter 19 to the screen 17. When this pulse is reflected by the screen 17, the time t ₁ after the reflection time T ₁ has passed.
Then, the pulse returns to the sensor 20.

Control circuit 27 detects the time difference T ₁ of the above t ₀ ~t _1. Further counter circuit 28 by counting crowded preparative reference pulse from the reference pulse oscillator 29 in the time the T _1, measures the reflection time T ₁ of the to the screen 17. Distance L ₁ between screen 17 and projector body 10
L ₁ = C · T _1/2 between and the reflection time T ₁ . Here, C is the speed of sound. Distance L ₁ from the front end of the left of the projector main body 10 to the screen 17 in this manner is measured.

Now it becomes time t _2, the ultrasonic transmitter 19 and the sensor 20 stops the operation. Instead, a mode is set in which the ultrasonic transmitter 21 and the sensor 22 work. The pulses from the ultrasonic transmitter 21 is sent towards the screen 17, and reflected by the screen 17, a pulse comes back to the receiving unit 20 at time t ₃ when passed through the reflection time T _2. Then the time T ₁ of the to time t ₂ ~t ₃ measured in the same manner as the T _1. If T ₂ is seen, L ₂ is calculated by the following equation.

L ₂ = the distance L _1, L ₂ of the C · T _2/2 In this way from the front end of the left and right of the projector main body 10 to the screen 17 will be seen, respectively. The ultrasonic sensor switching signal is applied to each of the sensors 20 and 22 so that the sensors 20 and 22 do not affect each other.
This is for separating the operation time of the operation.

From the measured L ₁ and L ₂ , the difference L ₁ −L ₂ is detected by the difference detection circuit 30 as shown in FIG. 4, and the torsion angle is calculated by the calculation circuit 31 according to the magnitude. I do. Then, the motor 16 is driven via the drive circuit 32 based on the calculation result of the circuit 31. Therefore, the projector body 10 is a rotating mechanism.
The projector 14 is driven to rotate with respect to the base 15, the rotation of the projector body 10 is adjusted, and the torsion correction is performed. That is, the state shown in FIG. 5A changes to the state shown in FIG. 5B, and the optical axis of the projector main body 10 is perpendicular to the screen 17 when viewed from above.

Knowing further the value of L ₁ or L _2, calculates the extension amount l of the lens 11 where the projector main body 10 and feeding the lens from the distance between the screen 17 amount calculating circuit 33 as shown in Figure 4 is shown in Figure 6 I do. The motor drive circuit 34 drives the motor 13 based on the calculation of the drawing amount 1 to move the optical lens 11 in the direction of the optical axis to perform the autofocus operation.

According to such a projector, the correction of the torsion relationship and the automatic focus adjustment of the lens 11 can be performed automatically, and a high-quality image free from defocus and image distortion can be obtained. In addition, it is not necessary to adjust the relative position between the projector body 10 and the screen 17 using a string as in the related art, and also, between the projector body 10 and the screen 17 in a place where the string cannot be used. The relative positional relationship can be easily determined. In addition, since the torsion correction and the focus adjustment are performed using ultrasonic waves, the installation adjustment can be performed without actually forming an image on the screen 17, and the setting in a bright place can be performed. Will be possible.

〔The invention's effect〕

As described above, according to the present invention, the determination unit obtains information on the twist angle of the projector main body from the difference between the output signals of the two or more sensors arranged near the front surface of the projector main body,
The torsion correction of the projector body is performed based on this information. Accordingly, the torsion correction is automatically performed, and a projector device that can form an image without distortion on the projection surface can be provided.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control circuit of a projector device according to an embodiment of the present invention, FIG. 2 is an external perspective view of a projector main body, FIG. 3 is a time chart showing a control operation, FIG.
FIG. 5 is a flowchart of a control operation, FIG. 5 is a plan view showing a twist correction operation, FIG. 6 is a side view showing an auto focus operation, FIG. 7 is a plan view showing an arrangement of a conventional projector device, The figure is a plan view showing the twist correction by a string, and FIG. 9 is a side view of the projector device in a state where a seat is installed. The names of the main parts in the drawings are as follows. 10 Projector body 14 Rotating mechanism 16 Motor 19, 21 Ultrasonic transmitter 20, 22 Sensor 27 Control circuit 30 Difference detection circuit 31 Torsion angle calculation circuit

Claims (1)

(57) [Claims] A projector body, at least two sensors, a determination unit, and a torsion correction mechanism, wherein the sensors are arranged near a front surface of the projector body;
The projector device, wherein the judging unit obtains information on a twist angle of the projector main body from a difference between output signals of the two or more sensors, and performs a twist correction of the projector main body based on the information. .