Image display device

Patent metadata

Field	Value
Publication number	US-10803801-B2
Application number	US-201916242594-A
Country	US
Kind code	B2
Filing date	Jan 8, 2019
Priority date	Jan 23, 2018
Publication date	Oct 13, 2020
Grant date	Oct 13, 2020

Abstract

An image display device includes: a light source emitting laser light; a screen on which an image is drawn by being two-dimensionally scanned by the laser light; a scanner causing the laser light to scan the screen; a light detector detecting a light amount of the laser light emitted from the light source; and a controller controlling the light source by changing a current value to drive the light source in response to a target light amount. The controller obtains a detection signal when driving the light source at a plurality of current setting values from the light detector, and corrects the current value with respect to the target light amount according to an arithmetic operation configured to suppress a difference between an output characteristic of the light source guessed by the obtained detection signal and a reference output characteristic.

First claim

What is claimed is:

1. An image display device comprising:
a light source emitting laser light;
a scanner causing the laser light to scan to draw an image;
a light detector detecting a light amount of the laser light emitted from the light source; and
a controller controlling the light source by changing a current value to drive the light source in response to a target light amount,
wherein the controller obtains a detection signal when driving the light source at a plurality of current setting values from the light detector, and corrects the current value with respect to the target light amount according to an arithmetic operation configured to suppress a difference between an output characteristic of the light source guessed by the obtained detection signal and a reference output characteristic, and
wherein the controller adds a value obtained by multiplying a value corresponding to the target light amount by a scale value to a current value of a light emitting threshold of the light source, to obtain the current value with respect to the target light amount, and obtains a corrected value of the current value of the light emitting threshold and a corrected value of the scale value according to the arithmetic operation configured to suppress the difference between the guessed output characteristic and the reference output characteristic.

2. The image display device according to claim 1 , wherein the controller sets two current setting values, and performs the arithmetic operation.

3. The image display device according to claim 1 , wherein the controller changes the current setting values in the arithmetic operation in response to a luminance setting value of the image to be displayed.

4. The image display device according to claim 1 , further comprising a temperature detector detecting an ambient temperature near the light source, wherein the controller changes the current setting values in the arithmetic operation in response to the ambient temperature detected by the temperature detector.

5. The image display device according to claim 1 , further comprising a temperature detector detecting an ambient temperature, wherein the controller changes a pulse width of a drive signal applied to the light source based on the ambient temperature detected by the temperature detector.

6. The image display device according to claim 1 , wherein the controller causes the light source to emit laser light for adjusting an output value of the light source at a predetermined position in a range of a display angle configured to display a display image of one frame, and adjusts an output of the light source based on the detection signal of the light detector with respect to the laser light for adjusting the output value.

7. An image display device comprising:
a light source emitting laser light;
a screen on which an image is drawn by being two-dimensionally scanned by the laser light;
a scanner causing the laser light to scan the screen;
a light detector detecting a light amount of the laser light emitted from the light source; and
a controller,
wherein the controller causes the light source to emit the laser light for adjusting an output value of the light source at a predetermined position in a range of a display angle configured to display a display image of one frame, and adjusts an output of the light source based on a detection signal of the light detector with respect to the laser light for adjusting the output value, and
wherein an emission position of the laser light for adjusting the output value is in a boundary between a drawing range of a first image and a drawing range of a second image in the range of the display angle.

8. The image display device according to claim 7 , further comprising a first screen and a second screen arranged in alignment with the first screen in a direction perpendicular to a traveling direction of the laser light,
wherein an emission position of the laser light for adjusting the output value is in a boundary between the first screen and the second screen.

9. The image display device according to claim 8 , further comprising a light shield provided in the boundary between the first screen and the second screen,
wherein the laser light for adjusting the output value is irradiated to the position of the light shield.

10. The image display device according to claim 9 , wherein the light shield includes a hollow formed at least at a position to which the laser light for adjusting the output value is irradiated.

11. The image display device according to claim 9 ,
wherein:
the first screen and the second screen are held by a common holder; and
the light shield is a wall part provided in the holder.

12. The image display device according to claim 11 , further comprising an actuator moving the holder in a direction parallel to the traveling direction of the laser light.

13. An image display device comprising:
a light source emitting laser light;
a screen on which an image is drawn by being two-dimensionally scanned by the laser light;
a scanner causing the laser light to scan the screen;
a light detector detecting a light amount of the laser light emitted from the light source; and
a controller,
wherein the controller causes the light source to emit the laser light for adjusting an output value of the light source at a predetermined position in a range of a display angle configured to display a display image of one frame, and adjusts an output of the light source based on a detection signal of the light detector with respect to the laser light for adjusting the output value,
wherein the screen comprises a first screen and a second screen arranged in alignment with the first screen in a direction perpendicular to a traveling direction of the laser light, and
wherein an emission position of the laser light for adjusting the output value is in a boundary between the first screen and the second screen.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Furuya Hiroyuki
• Uragami Susumu
• Yamamoto Yuta
• Kurozuka Akira
• Yamaguchi Mitsutaka

Classifications

• G09G3/025 Primary

  with scanning or deflecting the beams in two directions or dimensions · CPC title

• G09G2380/10

  Automotive applications · CPC title

• G02B26/12

  using multifaceted mirrors · CPC title

• G09G3/3233 Primary

  with pixel circuitry controlling the current through the light-emitting element · CPC title

• H04N9/3164

  using multiple light sources · CPC title