# US 11,442,346 B2 · Illumination device, projection system and operation methods thereof

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- Number: US 11,442,346 B2
- Document ID: US11442346B2
- Status: Granted
- Kind: B2
- Application number: 17/105,525
- Filed: 2020-11-26
- Published: 2021-06-03
- Granted: 2022-09-13
- Earliest claimed: 2019-11-28
- Assignees: Coretronic Corporation
- Applicants: Coretronic Corporation
- Inventors: Yu-Sheng Tsao; Yi-Shun Chang; Chan-Chih Lin
- Web page: https://patentgrep.com/patent/US11442346B2

## CPC

- G03B 21/16: Cooling; Preventing overheating
- G03B 21/2013: {Plural light sources}
- G02B 26/008: {in the form of devices for effecting sequential colour changes, e.g. colour wheels}
- G03B 21/2033: {LED or laser light sources}
- G03B 21/204: {using secondary light emission, e.g. luminescence or fluorescence (using different colours G03B33/00; if related to video signals H04N9/3197)}
- G03B 21/2053: {Intensity control of illuminating light (controlled by video signal processing H04N5/74 or H04N9/31)}
- G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D)
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

An illumination device, a projection system and operation methods thereof are provided. The illumination device includes a controller, a light source device, a phosphor wheel, a cooling device, and a temperature sensor. The light source device is configured to generate an illumination beam according to a light source control signal. The phosphor wheel is configured to convert the illumination beam into a conversion beam, adjust a rotation speed of the phosphor wheel according to a phosphor wheel control signal, and generate a rotation speed status signal. The temperature sensor is configured to sense a temperature value of the phosphor wheel to generate a temperature status signal. The cooling device is configured to adjust a cooling capacity according to a cooling control signal. The controller generates the cooling control signal according to the temperature status signal, the rotation speed status signal, and the light source control signal.

## Claims

### Claim 1

An illumination device, comprising a controller, a light source device, a phosphor wheel, a cooling device, and a temperature sensor, wherein
the light source device is coupled to the controller and configured to generate an illumination beam according to a light source control signal,
the phosphor wheel is coupled to the controller and configured to convert the illumination beam into a conversion beam, and the phosphor wheel adjusts a rotation speed of the phosphor wheel according to a phosphor wheel control signal and generates a rotation speed status signal,
the temperature sensor is coupled to the controller and configured to sense a temperature value of the phosphor wheel to generate a temperature status signal,
the cooling device is coupled to the controller and configured to adjust a cooling capacity according to a cooling control signal, and
the controller is configured to generate the phosphor wheel control signal and the light source control signal according to an operation mode signal, and the controller generates the cooling control signal according to the temperature status signal, the rotation speed status signal, and the light source control signal,
wherein the light source control signal is associated with a light source current driving the light source device, the temperature status signal is associated with the temperature value of the phosphor wheel, and the rotation speed status signal is associated with the rotation speed of the phosphor wheel, the controller obtains a reference temperature value of the phosphor wheel according to the light source control signal and the rotation speed status signal, and compares the temperature value of the phosphor wheel with the reference temperature value to generate the cooling control signal.

### Claim 2 (depends on 1)

The illumination device according to claim 1, wherein the controller comprises a lookup table, wherein the lookup table is configured to record a relationship among the rotation speed of the phosphor wheel, a current value of the light source current and the reference temperature value, and the controller generates the cooling control signal through the lookup table according to the rotation speed status signal and the light source current.

### Claim 3 (depends on 1)

The illumination device according to claim 1, wherein the controller determines whether a temperature difference between the temperature value of the phosphor wheel and the reference temperature value is within a preset temperature range to generate the cooling control signal.

### Claim 4 (depends on 3)

The illumination device according to claim 3, wherein the preset temperature range is ±5% of the reference temperature value.

### Claim 5 (depends on 1)

The illumination device according to claim 1, wherein the light source device comprises a light source driving circuit and a light source, wherein
the light source driving circuit is coupled to the controller and configured to generate the light source current according to the light source control signal, and
the light source is coupled to the light source driving circuit and configured to generate the illumination beam according to the light source current.

### Claim 6 (depends on 1)

The illumination device according to claim 1, wherein the phosphor wheel comprises a color wheel driving device and a substrate, wherein
the color wheel driving device is coupled to the controller and configured to drive the substrate to rotate according to the phosphor wheel control signal, and
the substrate is disposed on the color wheel driving device and configured to convert the illumination beam into the conversion beam.

### Claim 7 (depends on 1)

The illumination device according to claim 1, wherein the phosphor wheel comprises a rotation speed sensor, the rotation speed sensor being coupled to the controller and configured to sense the rotation speed of the phosphor wheel to generate the rotation speed status signal.

### Claim 8 (depends on 1)

The illumination device according to claim 1, wherein the rotation speed of the phosphor wheel and the light source current of the light source device are associated with the operation mode signal.

### Claim 9

A projection system, comprising an illumination device, a light valve and a projection lens, wherein
the illumination device comprises a controller, a light source device, a phosphor wheel, a cooling device, and a temperature sensor, wherein the light source device is coupled to the controller and configured to generate an illumination beam according to a light source control signal, the phosphor wheel is coupled to the controller and configured to convert the illumination beam into a conversion beam, the phosphor wheel adjusts a rotation speed of the phosphor wheel according to a phosphor wheel control signal and generates a rotation speed status signal, the temperature sensor is coupled to the controller and configured to sense a temperature value of the phosphor wheel to generate a temperature status signal, and the cooling device is coupled to the controller and configured to adjust a cooling capacity according to a cooling control signal, wherein the controller is configured to generate the phosphor wheel control signal and the light source control signal according to an operation mode signal, and the controller generates the cooling control signal according to the temperature status signal, the rotation speed status signal, and the light source control signal, wherein the light source control signal is associated with a light source current driving the light source device, the temperature status signal is associated with the temperature value of the phosphor wheel, and the rotation speed status signal is associated with the rotation speed of the phosphor wheel, the controller obtains a reference temperature value of the phosphor wheel according to the light source control signal and the rotation speed status signal, and compares the temperature value of the phosphor wheel with the reference temperature value to generate the cooling control signal,
the light valve is disposed on a transmission path of the illumination beam and configured to convert the illumination beam into an image beam, and
the projection lens is disposed on a transmission path of the image beam and configured to project the image beam.

### Claim 10

An operation method of an illumination device, comprising:
generating, by a controller, a phosphor wheel control signal and a light source control signal according to an operation mode signal;
generating, by a light source device, an illumination beam according to the light source control signal;
converting, by a phosphor wheel, the illumination beam into a conversion beam, adjusting, by the phosphor wheel, a rotation speed of the phosphor wheel according to the phosphor wheel control signal, and generating a rotation speed status signal;
sensing, by a temperature sensor, a temperature value of the phosphor wheel to generate a temperature status signal;
generating, by the controller, a cooling control signal according to the temperature status signal, the rotation speed status signal, and the light source control signal;
obtaining, by the controller, a reference temperature value of the phosphor wheel according to the light source control signal and the rotation speed status signal, and comparing the temperature value of the phosphor wheel with the reference temperature value to generate the cooling control signal, wherein the light source control signal is associated with a light source current driving the light source device, the temperature status signal is associated with the temperature value of the phosphor wheel, and the rotation speed status signal is associated with the rotation speed of the phosphor wheel; and
adjusting, by a cooling device, a cooling capacity according to the cooling control signal.

### Claim 11 (depends on 10)

The operation method of the illumination device according to claim 10, wherein the step of obtaining, by the controller, the reference temperature value of the phosphor wheel according to the light source control signal and the rotation speed status signal and comparing the temperature value of the phosphor wheel with the reference temperature value to generate the cooling control signal comprises:
recording, by a lookup table, a relationship among the rotation speed of the phosphor wheel, a current value of the light source current and the reference temperature value; and
generating, by the controller, the cooling control signal through the lookup table according to the rotation speed status signal and the light source current.

### Claim 12 (depends on 10)

The operation method of the illumination device according to claim 10, wherein the step of obtaining, by the controller, the reference temperature value of the phosphor wheel according to the light source control signal and the rotation speed status signal and comparing the temperature value of the phosphor wheel with the reference temperature value to generate the cooling control signal comprises:
determining, by the controller, whether a temperature difference between the temperature value of the phosphor wheel and the reference temperature value is within a preset temperature range to generate the cooling control signal.

### Claim 13 (depends on 12)

The operation method of the illumination device according to claim 12, wherein the preset temperature range is ±5% of the reference temperature value.

### Claim 14 (depends on 12)

The operation method of the illumination device according to claim 12, wherein the step of determining, by the controller, whether the temperature difference between the temperature value of the phosphor wheel and the reference temperature value is within the preset temperature range to generate the cooling control signal comprises:
increasing, by the cooling device, the cooling capacity according to the cooling control signal if the temperature difference exceeds the preset temperature range and the temperature value of the phosphor wheel is greater than the reference temperature value; and
reducing, by the cooling device, the cooling capacity according to the cooling control signal f the temperature difference exceeds the preset temperature range and the temperature value of the phosphor wheel is not greater than the reference temperature value.

### Claim 15 (depends on 10)

The operation method of the illumination device according to claim 10, wherein the step of generating the rotation speed status signal comprises:
sensing, by a rotation speed sensor, the rotation speed of the phosphor wheel to generate the rotation speed status signal.

### Claim 16 (depends on 10)

The operation method of the illumination device according to claim 10, wherein the rotation speed of the phosphor wheel and the light source current of the light source device are associated with the operation mode signal.

### Claim 17

An operation method of a projection system, comprising:
generating, by a controller, a phosphor wheel control signal and a light source control signal according to an operation mode signal;
generating, by a light source device, an illumination beam according to the light source control signal;
converting, by a phosphor wheel, the illumination beam into a conversion beam, adjusting, by the phosphor wheel, a rotation speed of the phosphor wheel according to the phosphor wheel control signal, and generating a rotation speed status signal;
sensing, by a temperature sensor, a temperature value of the phosphor wheel to generate a temperature status signal;
generating, by the controller, a cooling control signal according to the temperature status signal, the rotation speed status signal, and the light source control signal;
obtaining, by the controller, a reference temperature value of the phosphor wheel according to the light source control signal and the rotation speed status signal, and comparing the temperature value of the phosphor wheel with the reference temperature value to generate the cooling control signal, wherein the light source control signal is associated with a light source current driving the light source device, the temperature status signal is associated with the temperature value of the phosphor wheel, and the rotation speed status signal is associated with the rotation speed of the phosphor wheel;
adjusting, by a cooling device, a cooling capacity according to the cooling control signal;
converting, by a light valve, the illumination beam into an image beam; and
projecting, by a projection lens, the image beam.