CN102193286A - Projection system and projection method thereof - Google Patents

Abstract

The invention discloses a projection system and a projection method thereof. The projection system comprises a light source unit, a light source driving circuit, a scanning unit driving circuit, a detection unit and a controller. The light source driving circuit has a power modulation unit, and the scanning unit has a scanning lens. The projection method of the projection system comprises the following steps: (1) starting a projection system, driving a light source unit to generate low-power laser by a light source driving circuit, and driving a scanning unit by a scanning unit driving circuit; (2) the detection unit detects the running state of the scanning lens and generates a feedback signal; (3) the controller receives the feedback signal to judge the running state of the scanning lens and sends the signal to the light source driving circuit and the power modulation unit; (4) the power modulation unit receives the signal and controls the light source unit. The projection method of the projection system controls the output power of the laser through the power modulation unit, and prevents the laser output by the projection system from damaging human eyes.

Description

Projection system and projection method thereof

technical field

The invention relates to a projection technology, in particular to a projection system and a projection method thereof.

Background technique

Projection systems have been widely used in electronic products such as mobile phones, personal digital assistants, and portable projectors. An existing projection system includes a controller, a light source driving circuit, a scanning unit driving circuit, a light source unit, a scanning unit and a detection unit. The scanning unit has a swingable scanning mirror, and the detection unit is used to detect the operating state of the scanning mirror of the scanning unit and generate a corresponding feedback signal, the output feedback signal is accepted by the controller, and the controller controls the light source driving circuit and the scanning unit drive circuit. The projection method of the existing projection system is that when the projection system is turned on, the scanning unit driving circuit drives the scanning mirror to swing back and forth, and the light source driving circuit used to control the output of the corresponding image signal will drive the light source unit to generate and output high-power Laser, the laser is emitted in a scanning manner through the swing of the scanning mirror, the detection unit detects the operating state of the scanning mirror and generates a corresponding feedback signal, the controller accepts and judges the feedback signal, and then controls the light source driving circuit and the scanning unit driving circuit to perform One-step related operations. The projection method of the projection system can effectively monitor the damage caused by the operation error of the scanning unit during the projection process of the projection system.

However, when the above-mentioned projection system is just started, because the laser power generated by the light source unit is relatively high, if the scanning mirror cannot swing normally, the laser cannot be emitted in a scanning manner through the swing of the scanning mirror, and the laser will converge into a beam. The laser light directly enters the human eyes, which may cause serious damage to the human eyes.

Contents of the invention

The object of the present invention is to provide a projection system and projection method that can avoid damage to human eyes.

To achieve the above object, the projection system provided by the present invention includes a light source unit, a light source driving circuit, a scanning unit, a scanning unit driving circuit, a detection unit and a controller, the light source driving circuit is used to drive the light source unit to generate laser light, The light source driving circuit has a power modulating unit for regulating the laser power generated by the light source unit, the scanning unit has a swingable scanning mirror for reflecting the laser light generated by the light source unit, and the scanning unit driving circuit is used for driving the scanning mirror to swing The detection unit is used to detect the operating state of the scanning lens of the scanning unit and generate a corresponding feedback signal. The controller controls the light source driving circuit and the scanning unit driving circuit and receives the above feedback signal for judgment, so as to output the operating state signal of the scanning unit to power modulation unit.

The projection method of the projection system of the present invention comprises the following steps:

(1) Start the projection system, the controller sends driving signals to the light source driving circuit and the scanning unit driving circuit respectively, the light source driving circuit drives the light source unit to generate low-power laser light, and the scanning unit driving circuit drives the scanning unit;

(2) The detection unit detects the operating state of the scanning mirror of the scanning unit and generates a corresponding feedback signal to the controller;

(3) The controller receives the above feedback signal to judge whether the scanning lens is in normal operation state, and sends a signal to the light source drive circuit and its power modulation unit;

(4) The power modulation unit receives the signal and controls the light source unit.

As mentioned above, the projection method of the projection system of the present invention adjusts the level of laser output power through the power modulation unit, so that the projection system can only output low-power laser light when it is just started. After the power modulation unit determines the operating state of the scanning unit Then, the light source unit is controlled to prevent the excessively high-power laser from directly entering human eyes and causing damage to human eyes when the scanning unit is not operating normally.

Description of drawings

Fig. 1 is the functional block diagram of projection system of the present invention;

Fig. 2 is the working diagram of the scanning lens of the projection system of the present invention;

Fig. 3 is a schematic diagram of the laser beam sent by the scanning unit irradiating the projection lens when the projection system of the present invention is in operation;

4 is a flowchart of a projection method of the projection system of the present invention;

Fig. 5 is a flowchart of step (4) shown in Fig. 4 .

The reference signs in the figure are explained as follows:

Projection system 100

Controller 10 Light source drive circuit 20

Power modulation unit 201 Scanning unit drive circuit 30

Light source unit 40 Scanning unit 50

Scanning lens 501 Detection unit 60

Sensor 601 Projection Lens 70

Projection imaging area 701 Irradiation area 80

Detailed ways

In order to describe the technical content, structural features, achieved goals and effects of the present invention in detail, the following will be described in detail in conjunction with the embodiments and accompanying drawings.

Please refer to FIG. 1 , the projection system 100 of the present invention includes a controller 10 , a light source driving circuit 20 , a scanning unit driving circuit 30 , a light source unit 40 , a scanning unit 50 , a detection unit 60 and a projection lens 70 .

Please refer to FIG. 1 , the controller 10 of the projection system 100 of the present invention is used to control the light source driving circuit 20 and the scanning unit driving circuit 30 . The light source driving circuit 20 is used to drive the light source unit 40 to generate laser light. The light source driving circuit 20 has a power modulation unit 201 for regulating the laser power generated by the light source unit 40. The scanning unit driving circuit 30 is used to drive the scanning unit 50. The detection unit 60 is used to detect the running state of the scanning unit 50 and generate a corresponding feedback signal, and the output feedback signal is accepted by the controller 10 .

Referring to Fig. 2, the scanning unit 50 has a two-dimensional scanning mirror 501 made of micro-electromechanical system (MicroElectro Mechanical System, MEMS) technology, and the scanning mirror 501 can be driven by the scanning unit drive circuit 30 to simultaneously rotate The axis perpendicular to the paper and the axis parallel to the paper swing, so that the laser light output by the light source unit 40 can scan the image in two dimensions after being reflected by the scanning mirror 501, so that a complete image can be projected. In addition, when the scanning mirror 501 of the scanning unit 50 swings back and forth on the axis perpendicular to the paper surface and the axis parallel to the paper surface, each has two extreme positions, so when the laser light sent by the scanning unit 50 reaches the projection lens 70 An irradiation area 80 is formed.

2 and 3, the projection lens 70 is roughly sheet-shaped and has a roughly rectangular projection imaging area 701, the detection unit 60 includes a sensor 601, the sensor 601 is arranged on the projection lens 70 and is located in the projection imaging region 701. Outside area 701. The length and width of the irradiation area 80 are slightly larger than the projection imaging area 701 of the projection lens 70 . When the scanning mirror 601 swings, the sensor 601 receives the laser light in the irradiated area 80 and generates a corresponding feedback signal. The output feedback signal is accepted by the controller 10, and the controller 10 judges and outputs a signal of the operating state of the scanning mirror 501 to the light source driving circuit 20. The power modulation unit 201 can thus enable the projection system 100 of the present invention to perform related operations in the next step.

Referring to Fig. 1, Fig. 2, Fig. 3 and Fig. 4, the projection method of the projection system 100 of the present invention includes the following steps:

(1) Start the projection system 100, the controller 10 sends driving signals to the light source driving circuit 20 and the scanning unit driving circuit 30 respectively, the light source driving circuit 20 drives the light source unit 40 to generate low-power laser light, and the scanning unit driving circuit 30 drives the scanning unit 50 ;

(2) The detection unit 60 detects the operating state of the scanning mirror 501 of the scanning unit 50 and generates a corresponding feedback signal to the controller 10;

(3) The controller 10 receives the above-mentioned feedback signal to judge whether the scanning mirror 501 is running normally, and sends a signal to the light source driving circuit 20 and its power modulation unit 201;

(4) The power modulation unit 201 receives the signal and controls the light source unit 40 .

Please refer to FIG. 4 and FIG. 5 , the projection method of the projection system 100 of the present invention specifically includes two cases, and the corresponding embodiments are given below.

Embodiment one, its steps are as follows:

(1) Start the projection system 100, the controller 10 sends driving signals to the light source driving circuit 20 and the scanning unit driving circuit 30 respectively, the light source driving circuit 20 drives the light source unit 40 to generate low-power laser light, and the scanning unit driving circuit 30 drives the scanning unit 50 ; At this time, the scanning mirror 501 of the scanning unit 50 swings back and forth normally, and the laser beam is sent out in a scanning manner in cooperation with the synchronous action of the scanning mirror 501;

(2) The sensor 601 receives the laser light in the irradiated area 80 and generates a corresponding feedback signal to the controller 10;

(3) The controller 10 receives the above-mentioned feedback signal and judges that the scanning mirror 501 is running normally, and sends a signal to the light source driving circuit 20 and its power modulation unit 201;

(4) The power modulation unit 201 receives the signal and controls the light source unit 40 to emit laser light with normal power.

Embodiment two, its steps are as follows:

(1) Start the projection system 100, the controller 10 sends driving signals to the light source driving circuit 20 and the scanning unit driving circuit 30 respectively, the light source driving circuit 20 drives the light source unit 40 to generate low-power laser light, and the scanning unit driving circuit 30 drives the scanning unit 50 At this time, the scanning mirror 501 is not swinging normally, and the laser cannot move synchronously with the scanning mirror 501. The laser beam will be emitted from the projection lens 70 and converged into a beam. Since the laser light generated by the light source unit 40 is of low power, the laser beam directly enters the human eye and Cannot cause damage to human eyes;

(2) The sensor 601 cannot receive normal laser light and generates a corresponding feedback signal to the controller 10;

(3) The controller 10 receives the above-mentioned feedback signal and judges that the scanning mirror 501 is in an abnormal operating state, and sends a signal to the light source driving circuit 20 and its power modulation unit 201;

(4) The power modulation unit 201 receives the signal and controls the light source unit 40 to continue reducing the laser power or turn off the light source unit 40 .

As mentioned above, the projection method of the projection system 100 of the present invention adjusts the level of laser output power through the power modulation unit 201, so that the projection system 100 can only output low-power laser light when it is just started. The light source unit is controlled after the unit 40 is running, which can prevent the excessively high-power laser from directly entering human eyes and causing damage to human eyes when the scanning unit 40 is not operating normally.

Claims (7)

1. A projection system, comprising a light source unit, a light source driving circuit, a scanning unit, a scanning unit driving circuit, a detection unit and a controller, the light source unit is used to generate laser light, and the light source driving circuit is used to drive the light source unit The scanning unit has a swingable scanning mirror for reflecting the laser light generated by the light source unit, the scanning unit drive circuit is used to drive the scanning mirror to swing, and the detection unit is used to detect the operating state of the scanning mirror of the scanning unit and generate corresponding The feedback signal, the controller controls the light source driving circuit and the scanning unit driving circuit. It is characterized in that: the light source driving circuit has a power modulation unit to regulate the laser power generated by the light source unit. The controller receives the above feedback signal to judge and output the scanning unit. The operating state signal of the unit is sent to the power modulation unit of the light source driving circuit. 2. The projection system according to claim 1, further comprising a projection lens, the projection lens has a projection imaging area, the detection unit includes a sensor, and the sensor is located outside the projection imaging area. 3 . The projection system according to claim 2 , wherein an irradiation area is formed when the laser light is scanned by the scanning unit and reaches the projection lens, and the sensor receives the laser light in the irradiation area and generates the feedback signal. 4 . 4. The projection method of the projection system according to any one of claims 1 to 3, characterized in that it comprises the following steps: (1) Start the projection system, the controller sends driving signals to the light source driving circuit and the scanning unit driving circuit respectively, the light source driving circuit drives the light source unit to generate low-power laser light, and the scanning unit driving circuit drives the scanning unit; (2) The detection unit detects the operating state of the scanning mirror of the scanning unit and generates a corresponding feedback signal to the controller; (3) The controller receives the above feedback signal to judge whether the scanning lens is in normal operation state, and sends a signal to the light source drive circuit and its power modulation unit; (4) The power modulation unit receives the signal and controls the light source unit. 5. The projection method of the projection system according to claim 4, characterized in that: in the step (4), when the scanning mirror is operating normally, the power modulation unit controls the light source unit to emit laser light with normal power. 6. The projection method of the projection system according to claim 4, characterized in that: in the step (4), when the scanning mirror is not operating normally, the power modulation unit controls the light source unit to continue reducing the laser output power. 7. The projection method of the projection system according to claim 4, characterized in that: in the step (4), when the scanning mirror is in an abnormal operating state, the power modulation unit controls the light source unit to continue reducing the laser output power.

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