JP7700909B2 - Projection device, projection control method, and projection control program - Google Patents

Description

The present invention relates to a projection device, a projection control method, and a projection control program, and more particularly to a small and lightweight projection device that can be driven by a battery power source, for example.

Projection devices have been developed for some time now (see, for example, Patent Document 1). In recent years, portable projection devices that can be carried around have also been considered.

JP 2012-198439 A

However, when carrying a portable projection device in a bag, there is a possibility that something may push the power button by mistake. If projection starts inside the bag, power will be consumed unnecessarily. Also, problems may occur due to heat accumulation from the light source and projection light.

The object of the present invention is to prevent the projection device from turning on due to an erroneous operation even if the power button is pressed when the projection device is carried.

The present invention has been made in consideration of the above background, and has an objective of providing a projection device, a control method for a projection device, and a program that can prevent the projection device from turning on due to an erroneous operation even if the power button is pressed when the projection device is carried.

In order to solve the above problems, the projection device of the present invention is configured to be connectable to a commercial power source as an AC power source and a battery power source as a DC power source as a power source for lighting a projection light source, and includes a connector for connecting a video output device, a first switch for supplying DC power from the battery power source to a projection unit, a control means for determining whether the battery power source or the commercial power source is connected, and a control means for detecting whether the voltage of a power pin of the connector is equal to or higher than a predetermined threshold value or a video signal is output from the connector when it is determined that the battery power source is connected and a user operation is received on an operation button for turning on the projection light source. and a determination means for determining whether or not a video signal is being input from the connector, wherein when the determination means determines that the voltage of the power pin of the connector is equal to or higher than a predetermined threshold value or that a video signal is being input from the connector, the control means shorts the first switch to start turning on the projection light source, and when it is determined that the commercial power source is connected and a user operation on the operation button is accepted, the control means supplies power from the commercial power source to the projection unit to turn on the projection light source without determining whether the voltage of the power pin of the connector is equal to or higher than a predetermined threshold value or that a video signal is being input from the connector.

According to the present invention, when carrying the projection device, the projection device will not turn on due to an erroneous operation even if the power button is pressed.

1 is a configuration diagram of a projection device according to a first embodiment of the present invention. FIG. 2 is a diagram showing a pin assignment of an HDMI connector. 5 is a flowchart for explaining a start-up operation of the projection device of the present invention. FIG. 11 is an explanatory diagram for explaining an HDMI negotiation flow. FIG. 11 is a configuration diagram of a projection device according to a second embodiment of the present invention. FIG. 2 is a diagram showing the pin assignment of a DP connector. FIG. 2 is a diagram showing a pin assignment of a VGA connector.

Below, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail with reference to the drawings. Note that each figure is merely a schematic illustration to allow a sufficient understanding of this embodiment. In addition, in each figure, common or similar components are given the same reference numerals, and duplicate explanations thereof will be omitted.

First Embodiment
FIG. 1 is a diagram showing the configuration of a projection device according to a first embodiment of the present invention.
The projection system S includes a projection device 100, a video output device 200 (external device), an HDMI (registered trademark) cable 150 that connects these devices, and a battery power source E that supplies DC power to the projection device 100.

The projection device 100 includes a standby power supply control unit 11, a main CPU 20, a projection unit 30, an HDMI receiver 40, a semiconductor switch 12, a mechanical switch 13, and a FAN 60. The semiconductor switch 12 is a high-performance semiconductor power switch that has built-in protection circuits against overcurrent and overheating, and a circuit that absorbs the energy of an inductive load, etc., and is not destroyed even in abnormal conditions such as a short circuit and can maintain its function as a switch. An IPD (Intelligent Power Device), IPS (Intelligent Power switch), Smart Switch, or Hi-side/Lo-side switch can be used as the semiconductor switch 12.

The battery power supply E is a secondary battery, but it may also be a primary battery. The negative terminal of the battery power supply E is connected to the standby power supply control unit 11, the main CPU 20, the projection unit 30, and the FAN 60. The positive terminal of the battery power supply E is connected to the standby power supply control unit 11 and one end of the semiconductor switch 12. The other end of the semiconductor switch 12 is connected to the main CPU 20, the projection unit 30, and the FAN 60. Both ends of the mechanical switch 13 are connected to the standby power supply control unit 11.

The projection device 100 is configured to be able to connect a commercial power source as an AC power source and a battery power source as a DC power source as a power source for lighting the projection light source. When a user operation on an operation button for lighting the projection light source is received, the standby power supply control unit 11 (control means, determination means) determines whether the voltage of the power supply pin of the connector is equal to or higher than a predetermined threshold value.

However, the main CPU 20 (control means) can determine in advance whether or not the device is battery-powered. The main CPU 20 (control means) can determine whether or not the device is battery-powered, for example, based on the voltage value input from the power source. Alternatively, when the device is battery-powered, a pulse signal is output from the battery, which is different from when the device is powered by an AC power source, so that it can determine whether or not the device is battery-powered.

In this way, by determining whether the device is battery-powered before determining whether the voltage of the power pin of the connector is equal to or higher than a predetermined threshold, if it is determined that the projection device 100 is connected to a commercial power source as an AC power source as the power source for lighting the projection light source, when a user operation is received on the operation button (power button) for turning on the projection light source, there is no need to determine whether the voltage of the power pin of the connector is equal to or higher than a predetermined threshold. When a commercial power source as an AC power source is connected as the power source for lighting the projection light source, there is no need to prohibit the projection light source from being turned on, so when the power button is pressed by the user, the light source turns on immediately. Therefore, the user can use the projection device 100 without any discomfort.

The standby power supply control unit 11 receives a power supply voltage of +5V (5V Power) from the video output device 200 via the HDMI cable 150 and the HDMI receiver 40. In addition, both ends of the mechanical switch 13 are connected to the standby power supply control unit 11. In this state, when the mechanical switch 13 transitions from the OFF state to the ON state, the standby power supply control unit 11 sets the semiconductor switch 12 to the ON state when it detects a power supply voltage of +5V from the video output device 200.

On the other hand, when the standby power supply control unit 11 cannot detect a power supply voltage of +5V from the video output device 200, it keeps the semiconductor switch 12 in the OFF state. In other words, when the standby power supply control unit 11 cannot detect a power supply voltage of +5V from the video output device 200, it prohibits the main CPU 20, the projection unit 30, and the FAN 60 from being driven.

After starting up, the main CPU 20 transmits a HPD (Hot Plug Detect) signal to the video output device 200 via the HDMI receiver 40 and the HDMI cable 150. This establishes a connection between the projection device 100 and the video output device 200. The main CPU 20 processes the video signal output by the HDMI receiver 40 and outputs the processed image to the projection unit 30. The main CPU 20 exchanges various types of information with the video output device 200 using a CEC (Consumer Electronics Control) signal.

The projection unit 30 projects the image processed by the main CPU 20 onto an external projection target (such as a screen). The projection unit 30 includes a light source (not shown) and is prone to heat generation. The FAN 60 cools the projection unit 30.

The HDMI receiver 40 receives a video signal from the video output device 200 and outputs the received video signal to the main CPU 20. The HDMI receiver 40 also transmits device information of the projection device 100 to the video output device 200 using a DDC (Display Data Channel) signal.

The video output device 200 is, for example, a PC (Personal Computer) or a BD (Blu-ray Disc) player, and includes a CPU 220, an image processing unit 230, an HDMI transmitter 240, and a connector 250. The CPU 220 controls the entire video output device 200. The image processing unit 230 includes a VRAM (not shown), and processes images stored in the VRAM under the control of the CPU 220. The HDMI transmitter 240 transmits a video signal to the HDMI receiver 40 of the projection device 100.

The HDMI cable 150 transmits video signals from the video output device 200 to the projection device 100. The HDMI cable 150 also transmits device information and authentication information between the video output device 200 and the projection device 100. The connectors 50 and 250 are 19-pin connectors, and the pin assignment is shown in FIG. 2. For example, pins 1 to 9 are TMDS_DATA, and pins 10 to 12 are TMDS_CLOCK. Also, pin 17 is ground, pin 18 is "5V" Power, and pin 19 is "HPD". In TMDS (Transition Minimized Differential Signaling), four channels are grouped together and used in a unit called a "link". Of the four channels, one channel each is assigned to RGB video signals, and one channel is assigned to a signal for synchronizing the clock frequency.

FIG. 3 is a flow chart for explaining the operation of the projection device of the present invention.
This flow starts when the battery power source E is attached, and is repeated until the battery power source E is depleted or removed.
The standby power supply control unit 11 (determination means) first performs a general initialization process (S1), and then determines whether the mechanical switch 13 is turned on (Power key IN) (S2). That is, the standby power supply control unit 11 determines whether the mechanical switch 13 transitions from an OFF state to an ON state. If the mechanical switch 13 does not transition from an OFF state to an ON state (No in S2), the standby power supply control unit 11 executes another polling process that periodically makes an inquiry (S3), and repeats the determination of whether the mechanical switch 13 is turned on (S2).

On the other hand, if the mechanical switch 13 transitions from the OFF state to the ON state (Yes in S2), the standby power supply control unit 11 (determination means) determines whether or not a 5V power supply voltage (5V Power) from the video output device 200 has been detected (S4). If the 5V power supply voltage is not detected (No in S4), the standby power supply control unit 11 executes another polling process (S3) and repeats the determination of whether the mechanical switch 13 is turned on (S2). On the other hand, if the 5V power supply voltage is detected (Yes in S4), the standby power supply control unit 11 sets the semiconductor switch 12 to the ON state (S5).

In S4, when the standby power supply control unit 11 (determination means) determines whether or not a 5V power supply voltage (5V Power) from the video output device 200 has been detected, since the projection device 100 and the video output device 200 are connected by the HDMI cable 150, the power supply voltage is not completely 0V even if no video source is being output from the video output device 200. Therefore, for example, it can be determined whether or not the voltage of the power supply pin of the connector 50 of the projection device 100 is equal to or higher than a predetermined threshold value.

This activates the main CPU 20, the projection unit 30, and the FAN 60, and the light source of the projection unit 30 turns on. In other words, when the standby power supply control unit 11 detects the transition of the mechanical switch 13 and the 5V power supply voltage, it activates the main CPU 20, the projection unit 30, and the FAN 60. After the process of S5, the standby power supply control unit 11 (determination means) executes another polling process (S3) and repeats the determination of whether the mechanical switch 13 is turned on (S2).

FIG. 4 is an explanatory diagram for explaining the HDMI negotiation flow.
Here, the description will be given assuming that an HDMI cable 150 is connected between the projection device 100 and the video output device 200 .
When the video output device 200 is powered on, the 5V power pin of the connector 250 goes to a HIGH level. This causes the 5V power pin of the connector 50 of the projection device 100 to also go to a HIGH level. In the projection device 100, the standby power supply control unit 11 detects the HIGH level state of the 5V power pin (S4), and the main CPU 20 transmits an HPD signal to the video output device 200 (S10).

The video output device 200 detects the HPD signal (S11) and instructs the projection device 100 to transmit EDID (Extended Display Identification Data) (S12). The projection device 100 returns the EDID to the video output device 200 (S13). The video output device 200 reads the EDID (S14). Here, the EDID is data stored in a sink device such as the projection device 100. This data includes the "resolution," "refresh rate," and "color depth" that the projection device 100 can display, as well as the corresponding "audio format."

After the process of S14, the video output device 200 judges the capabilities of the sink device (S15) and judges the capabilities of the AV format (S16). Furthermore, the video output device 200 and the projection device 100 perform HDCP (High-bandwidth Digital Content Protection) authentication (S17, S18). HDCP authentication is an encryption technology that prevents copyrighted video content from being illegally copied while being transmitted to a display device. In HDCP authentication, the video sender (HDCP transmitter) such as a computer and the receiver (HDCP receiver) such as a display each have their own built-in encryption key, which is used to authenticate that the device is a genuine HDCP-compatible device, exchange encryption keys, and encrypt and decrypt video data.

After completing HDCP authentication in S17 and S18, the video output device 200 transmits TMDS to the projection device 100 (S19). As a result, the projection device 100 receives the TMDS (S20).

As described above, according to the projection device 100 of this embodiment, when the video output device 200 is connected via the HDMI cable 150 and the video output device 200 is operating, the semiconductor switch 12 goes to the ON state when the standby power supply control unit 11 detects the transition of the mechanical switch 13 and the 5V power supply voltage from the video output device 200. This starts up the main CPU 20, the projection unit 30, and the FAN 60, and the light source of the projection unit 30 turns on.

Second Embodiment
Although the standby power supply control unit 11 in the first embodiment detects the 5V power supply voltage from the video output device 200, it may detect a video signal.

FIG. 5 is a diagram showing the configuration of a projection device according to a second embodiment of the present invention.
In the projection device 101 of this embodiment, compared to the projection device 100 of the first embodiment, a signal line of a +5V power supply is not connected between the HDMI receiver 40 and the standby power supply control unit 11. In other words, the +5V power supply connects between the HDMI receiver 40 and the HDMI transmitter 240. In addition, various signal lines are connected between the HDMI receiver 40 and the standby power supply control unit 11. When the video output device 200 transmits TMDS to the projection device 101, the projection device 101 receives the TMDS and detects the video signal. In this way, the detection of the video signal from the video output device 200 is performed by the TMDS channel between the HDMI transmitter 240 of the video output device 200 and the HDMI receiver 40 of the projection device 101.

The standby power supply control unit 11 also has the functional units of an EDID response unit 11a and an HDCP authentication unit 11b. As a result, the standby power supply control unit 11 of the projection device 101 not only performs the 5V HIGH detection (S4) of the HDMI negotiation flow (Figure 4), but also HPD transmission (S10), EDID response (S13), and HDCP authentication (S18).

When HDCP authentication (S18) is completed, the standby power supply control unit 11 sets the semiconductor switch 12 to the ON state. This starts up the main CPU 20, the projection unit 30, and the FAN 60, and the light source of the projection unit 30 turns on. The main CPU 20 then receives a video signal via the HDMI receiver 40. The main CPU 20 sends the received video signal to the projection unit 30, which projects the video signal onto a target object such as a screen.

As described above, according to the projection device 101, the standby power supply control unit 11 performs HDMI negotiation, and sets the semiconductor switch 12 to the ON state after the negotiation is completed. In other words, when a video signal cannot be input, the semiconductor switch 12 is in the OFF state, and when a video signal can be input, the semiconductor switch 12 is in the ON state. Therefore, when the portable projection device 101 is carried in a bag, even if the power button is pressed by mistake due to being pressed by something, DC power will not be output unless the connected video output device 200 is driven, so that lighting due to erroneous operation can be prevented.
The control means prohibits the projection light source from being turned on when a battery power source is connected as the power source for turning on the projection light source. Therefore, when the projection device 101 is connected to a commercial power source as an AC power source as the power source for turning on the projection light source, the light source is turned on immediately when the power button is pressed by the user. Therefore, the user can use the projection device 101 without feeling uncomfortable.

(Modification)
The present invention is not limited to the above-described embodiment, and various modifications are possible, for example, as follows.
(1) The projection device 100 of the above embodiment uses HDMI, but it is also possible to use DP (Display Port (registered trademark) ) or VGA (Video Graphics Array). FIG. 6 shows the pin assignment of a DP connector, and FIG. 7 shows the pin assignment of a VGA connector. However, VGA is compliant with the VESA (Video Electronics Standards Association) standard, and pin 9 is set to "DDC +5 volt load."

[Additional Notes]
<Claim 1>
A projection device configured to be connectable to a commercial power source as an AC power source and a battery power source as a DC power source as a power source for lighting a projection light source,
A connector for connecting an external device;
a determination means for determining whether or not a voltage of a power pin of the connector is equal to or higher than a predetermined threshold value, or whether or not a video signal is being input from the connector, when the battery power source is connected and a user operation on an operation button for turning on the projection light source is received;
a control means for starting lighting of the projection light source when the voltage determined by the determination means is equal to or greater than the predetermined threshold value or when the video signal is being input, and forbidding lighting of the projection light source when the voltage determined by the determination means is less than the predetermined threshold value or when the video signal is not being input;
A projection device comprising:
<Claim 2>
the external device is a video output device,
a first switch (semiconductor switch) that supplies DC power from the battery power source to a projection unit;
The projection device according to claim 1, characterized in that the control means is connected to the battery power source, shorts the first switch at a timing indicating a change in state of the second switch (mechanical switch), prohibits shorting of the first switch when no voltage is detected at the power pin of the connector, and allows shorting of the first switch when voltage is detected at the power pin of the connector.
<Claim 3>
The connector is an HDMI (registered trademark) connector or a DP connector,
A second control unit is further provided on the output side of the first switch,
3. The projection device according to claim 2, wherein the determining unit determines the connection with the video output device via the connector.
<Claim 4>
4. The projection device according to claim 1, wherein the control unit controls the projection light source after the determination unit determines that the connection with the external device has been completed.
<Claim 5>
the external device is a video output device,
a first switch that supplies DC power from the battery power source to a projection unit;
Equipped with
The projection device according to claim 2, characterized in that the control means is connected to the battery power source, shorts the first switch when the second switch is shorted, prohibits the shorting of the first switch when a video signal cannot be input from the connector, and allows the shorting of the first switch when a video signal is input from the connector.
<Claim 6>
A connector for connecting an external control device;
a first switch for supplying DC power from a battery power source to a drive circuit;
a control means connected to the battery power source and inhibiting the supply of DC power when a voltage at a power pin of the connector cannot be detected.
<Claim 7>
A power supply control method executed by a control unit connected to a battery power supply of a power supply device including a connector for connecting an external control device and a power supply circuit for supplying DC power to a drive circuit, the method comprising:
A power supply control method comprising the steps of: prohibiting the supply of DC power when a voltage at a power pin of the connector cannot be detected.
<Claim 8>
A power supply control program to be executed by a control unit connected to a battery power supply of a power supply device including a connector for connecting an external control device and a power supply circuit for supplying DC power to a drive circuit,
A power supply control program, comprising: a power supply control section for inhibiting the supply of DC power when a voltage of the power supply of the connector cannot be detected.

10 Power supply device 11 Standby power supply control unit (control means, determination means)
12 Semiconductor switch (first switch)
13 Mechanical switch (mechanical switch)
20 Main CPU (control means)
30 Projection unit 40 HDMI receiver 50 Connector 100, 101 Projection device 150 HDMI cable 200 Video output device (external device)

Claims (5)

A projection device configured to be connectable to a commercial power source as an AC power source and a battery power source as a DC power source as a power source for lighting a projection light source,
A connector for connecting a video output device;
a first switch that supplies DC power from the battery power source to a projection unit;
a control means for determining whether the battery power source or the commercial power source is connected;
a determination means for determining whether a voltage of a power supply pin of the connector is equal to or higher than a predetermined threshold value or whether a video signal is being input from the connector when it is determined that the battery power supply is connected and a user operation on an operation button for turning on the projection light source is received,
The control means, when the determination means determines that the voltage of the power pin of the connector is equal to or higher than a predetermined threshold value or that a video signal is being input from the connector, shorts the first switch to start turning on the projection light source, and when it is determined that the commercial power source is connected and a user operation on the operation button is accepted, supplies power from the commercial power source to the projection unit to turn on the projection light source without determining whether or not the voltage of the power pin of the connector is equal to or higher than a predetermined threshold value or that a video signal is being input from the connector . The projection device according to claim 1, characterized in that the control means does not short-circuit the first switch when the determination means determines that a voltage equal to or higher than the predetermined threshold cannot be detected at the power pin of the connector or that no video signal is being input from the connector. The connector is an HDMI (registered trademark) connector or a DP (registered trademark) connector,
3. The projection device according to claim 2, wherein the determining unit determines the connection with the video output device via the connector. A projection control method for a projection device that is configured to be connectable to a commercial power source as an AC power source and a battery power source as a DC power source as a power source for lighting a projection light source, comprising:
determining whether the battery power source or the commercial power source is connected;
when it is determined that the battery power source is connected and when a user operation is received on an operation button for turning on the projection light source, it is determined whether a voltage of a power pin of a connector for connecting a video output device is equal to or higher than a predetermined threshold value, or whether a video signal is being input from the connector;
when it is determined that the voltage of the power pin of the connector is equal to or higher than a predetermined threshold value, or when a video signal is input from the connector, a first switch that supplies DC power from the battery power source to a projection unit is short-circuited to start lighting the projection light source;
A projection control method characterized in that, when it is determined that the commercial power source is connected and a user operation on the operation button is received, power from the commercial power source is supplied to the projection unit to turn on the projection light source without determining whether the voltage of the power pin of the connector is above a predetermined threshold value or whether a video signal is input from the connector. A projection control program for a projection device configured to be connectable to a commercial power source as an AC power source and a battery power source as a DC power source as a power source for lighting a projection light source,
determining whether the battery power source or the commercial power source is connected;
when it is determined that the battery power source is connected and when a user operation is received on an operation button for turning on the projection light source, it is determined whether a voltage of a power pin of a connector for connecting a video output device is equal to or higher than a predetermined threshold value, or whether a video signal is being input from the connector;
when it is determined that the voltage of the power pin of the connector is equal to or higher than a predetermined threshold value, or when a video signal is input from the connector, a first switch that supplies DC power from the battery power source to a projection unit is short-circuited to start lighting the projection light source;
A projection control program characterized by: when it is determined that the commercial power source is connected and a user operation on the operation button is received, supplying power from the commercial power source to the projection unit and turning on the projection light source without determining whether the voltage of the power pin of the connector is above a predetermined threshold value or whether a video signal is input from the connector.