Semiconductor device, electronic device, ambient illuminance measuring method, and recording medium

Abstract

For a semiconductor device, an electronic device, a surrounding light illuminance measurement method, and a computer-readable recording medium, there are provided: a light measurer configured to measure a surrounding light illuminance of a display panel on a side opposite to a display surface of the display panel including a self-emitting element; a storage configured to store a plurality of first measurement values measured by the light measurer in a plurality of first measurement periods shorter than a turn-on / off period of the self-emitting element in synchronization with a synchronization signal of the display panel; and a calculation unit configured to calculate a self-emitting illuminance of the self-emitting element based on the first measurement values stored in the storage, and calculate the surrounding light illuminance by subtracting a value based on the self-emitting illuminance from a second measurement value measured by the light measurer in a second measurement period longer than the first measurement period.

Description

TECHNICAL FIELD

[0001] The present application relates to a semiconductor device provided with a light measurer arranged on the back side of a display panel in order to measure ambient light illuminance, an electronic device, an ambient light illuminance measuring method, and a computer-readable recording medium. BACKGROUND

[0002] An illuminance sensor that measures ambient light illuminance is used in order to control the brightness of a display of a smartphone. In the past, the illuminance sensor was arranged on the upper portion of the display to measure ambient light illuminance, but with the large size and full screen of the display of a smartphone, the illuminance sensor is arranged on the back side (back, below the display) of the display of the smartphone.

[0003] In the case where the illuminance sensor is arranged on the back side of the display, light from the display also irradiates the illuminance sensor together with ambient light. Therefore, it is necessary to obtain ambient light by subtracting the light of the display from the output result of the illuminance sensor.

[0004] It is known that an electronic device provided with a display and a light sensor arranged on the back side of the display and receiving ambient light that has passed through the display (U.S. Patent Application Publication No. 2021 / 0056896 Specification). The electronic device calculates ambient light illuminance based on a count value of a first subframe in which incident light of the light sensor of a first subframe modulated by at least one modulation parameter and a second subframe modulated by at least one modulation parameter is integrated during a vertical synchronization signal of the display and a count value of the second subframe. SUMMARY

[0005] Technical problem to be solved by the present application

[0006] However, the above-described prior art does not take into account the timing of turning on and off of the light emission of the display.

[0007] Therefore, there is a problem that it is difficult to calculate accurate ambient light illuminance because the light of the display cannot be accurately subtracted.

[0008] An object of one embodiment of the present application is to provide a semiconductor device, an electronic device, an ambient light illuminance measuring method, and a computer-readable recording medium that can calculate more accurate ambient light illuminance.

[0009] To solve the above problems, one embodiment of a semiconductor device according to the present application includes: a light measurer configured on the side opposite to a display surface of a display panel including a self-luminous element, for measuring ambient light intensity of the display panel; a storage configured to store first measurement values measured by the light measurer in a plurality of first measurement periods shorter than a turn-on / off period of the self-luminous element, in synchronization with a synchronization signal of the display panel; and a calculation portion configured to calculate luminous intensity of the self-luminous element based on the first measurement values stored in the storage, and to calculate the ambient light intensity by subtracting a value based on the luminous intensity from a second measurement value measured by the light measurer in a second measurement period longer than the first measurement period.

[0010] To solve the above problems, another semiconductor device according to the present application includes: a light measurer configured on the side opposite to a display surface of a display panel including a self-luminous element, for measuring ambient light intensity of the display panel; a storage configured to store a plurality of first measurement values measured by the light measurer in a first measurement period shorter than a turn-on / off period of the self-luminous element, in synchronization with a synchronization signal of the display panel; and a communication interface configured to transmit the first measurement values and a second measurement value measured by the light measurer in a second measurement period longer than the first measurement period, for calculating luminous intensity of the self-luminous element based on the first measurement values, and calculating the ambient light intensity by subtracting a value based on the luminous intensity from the second measurement value.

[0011] To solve the above problems, an electronic device according to the present application includes: a display panel including a self-luminous element; and a semiconductor device configured on the side opposite to a display surface of the display panel, the semiconductor device including: a light measurer for measuring ambient light intensity of the display panel; a storage configured to store a plurality of first measurement values measured by the light measurer in a first measurement period shorter than a turn-on / off period of the self-luminous element, in synchronization with a synchronization signal of the display panel; and a calculation portion configured to calculate luminous intensity of the self-luminous element based on the first measurement values stored in the storage, and to calculate the ambient light intensity by subtracting a value based on the luminous intensity from a second measurement value measured by the light measurer in a second measurement period longer than the first measurement period.

[0012] To solve the above problems, a surrounding light illuminance measuring method according to an embodiment of the present application is a surrounding light illuminance measuring method for measuring surrounding light illuminance of a display panel provided with a self-emitting element, including: a storage step of storing, in synchronization with a synchronization signal of the display panel, a plurality of first measurement values measured by a light measurer disposed on a side opposite to a display surface of the display panel during a first measurement period shorter than a turn-on / off period of the self-emitting element in a storage device; and a calculation step of calculating an emission illuminance of the self-emitting element based on the first measurement values stored in the storage device, and calculating the surrounding light illuminance by subtracting a value based on the emission illuminance from a second measurement value measured by the light measurer during a second measurement period longer than the first measurement period.

[0013] To solve the above problems, a computer-readable recording medium according to an embodiment of the present application records a program based on the surrounding light illuminance measuring method according to an embodiment of the present application.

[0014] According to an embodiment of the present application, it is possible to provide a semiconductor device, an electronic device, a surrounding light illuminance measuring method, and a computer-readable recording medium that can calculate more accurate surrounding light illuminance. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a top view of an electronic device according to Embodiment 1.

[0016] Figure 2 is a cross-sectional view taken along line A-A' shown in Figure 1 .

[0017] Figure 3 is a block diagram of a semiconductor device provided in the electronic device.

[0018] Figure 4 is a block diagram of a modification of the semiconductor device.

[0019] Figure 5 is a cross-sectional view for explaining a relationship between surrounding light of a display panel provided in the electronic device and emission of a self-emitting element of the display panel.

[0020] Figure 6 is a coordinate graph for explaining a measurement period of a light measurer provided in the semiconductor device.

[0021] Figure 7 is a schematic view for explaining a manner of storing measurement data measured in the measurement period in a storage device provided in the semiconductor device.

[0022] Figure 8is a flowchart showing the operation of the electronic device.

[0023] Figure 9 is a block diagram of another modification example of the semiconductor device.

[0024] Figure 10 is a block diagram of still another modification example of the semiconductor device.

[0025] Figure 11 is a flowchart showing the operation of the electronic device according to Embodiment 2.

[0026] Figure 12 is a coordinate diagram for describing the operation of the electronic device according to Embodiment 3.

[0027] Figure 13 is a flowchart showing the operation of the electronic device. DETAILED DESCRIPTION

[0028] 〔Embodiment 1〕

[0029] Hereinafter, an embodiment of the present application will be described in detail.

[0030] Figure 1 is a plan view of the electronic device 1 according to Embodiment 1. Figure 2 is a cross-sectional view taken along the line A-A' shown in Figure 1 .

[0031] The electronic device 1 is provided with a display panel 2 and a semiconductor device 3 disposed on the side opposite to the display surface 18 of the display panel 2. The electronic device 1 can be, for example, a portable electronic device such as a smartphone, a game machine, a clock, a television, a personal computer, a monitor, or the like. The display panel 2 has a substrate 9, a TFT (Thin Film Transistor) layer 10 formed on the substrate 9, an organic EL (Electro-Luminescence) layer 11 formed on the TFT layer 10, and a cover glass 12 formed on the organic EL layer 11.

[0032] The organic EL layer 11 has a plurality of pixels 19 arranged in a matrix shape in the X direction and the Y direction. Each pixel 19 includes a red light-emitting element 17R (self-light-emitting element), a green light-emitting element 17G (self-light-emitting element), and a blue light-emitting element 17B (self-light-emitting element) arranged in the X direction.

[0033] The display panel 2 also has a gate driver 15 for controlling the timing of operation of each light emitting element 17R, 17G, 17B, a source driver 16 for supplying display data to each light emitting element 17R, 17G, 17B, and a display circuit 13 that supplies a vertical synchronization signal (VSYNC, Vertical Synchronizing signal) S1 (synchronization signal) for controlling the above-mentioned timing of operation, a signal indicating the light emission duty ratio of each light emitting element 17R, 17G, 17B, and the like to the gate driver 15 and the semiconductor device 3, and supplies a display signal for each light emitting element 17R, 17G, 17B to the source driver 16. Each light emitting element 17R, 17G, 17B can be, for example, an OLED (Organic Light Emitting Diode).

[0034] Figure 3 is a block diagram of the semiconductor device 3 provided in the electronic device 1.

[0035] The semiconductor device 3 has a light measurer 4 for measuring the ambient light illuminance of the display panel 2, a storage device 5 for storing the measurement value measured by the light measurer 4, an AD conversion circuit 20 that AD-converts the measurement value measured by the light measurer 4, a control section 21 that writes the measurement value AD-converted by the AD conversion circuit 20 into the storage device 5, and a communication interface 22 that reads out the measurement value stored in the storage device 5 and transmits it to the display circuit 13 that controls the display panel 2. The display circuit 13 transmits a control signal for controlling the brightness of each light emitting element 17R, 17G, 17B to the source driver 16. The communication interface 22, for example, conforms to I2C (Inter-Integrated Circuit), SPI (Serial Peripheral Interface).

[0036] Note that the case where the communication interface 22 reads out the measurement value stored in the storage device 5 is described, but the present application is not limited thereto. The control section 21 can also read out the above-mentioned measurement value. Figure 4 is a block diagram of the semiconductor device 3A related to a modification. The same reference numerals are attached to the same structural elements as those described above. The detailed description of these structural elements is not repeated.

[0037] The semiconductor device 3A has a control section 21A. In the case where the control section 21A reads out the measurement value stored in the storage device 5, as shown in Figure 4 the control section 21A can also perform the writing and reading of the measurement value to and from the storage device 5, and transmit the measurement value read out from the storage device 5 from the control section 21A to the communication interface 22.

[0038] The light measuring device 4 can be set separately for each of the multiple pixels 19, or it can be set separately for each of the multiple pixels 19.

[0039] Storage device 5 includes: a first storage unit 6, which synchronizes with the vertical synchronization signal S1 of display panel 2 for a first measurement period T1 shorter than the on / off period of each light-emitting element 17R, 17G, 17B. Figure 6 The first measurement value measured by the light measuring device 4 is stored; and the second storage unit 7 stores the second measurement value during a second measurement period T2 that is longer than the first measurement period T1. Figure 6 The second measurement value measured by the light measuring device 4 is stored. The first storage unit 6 includes a memory array.

[0040] The display panel 2 has a calculation unit 8, which calculates the luminous illuminance of each light-emitting element 17R, 17G, 17B based on a first measurement value, and calculates the ambient illuminance by subtracting the value based on the luminous illuminance from the second measurement value measured by the light meter 4 during the second measurement period T2.

[0041] In addition, the computing unit 8 can also be like Figure 9 as well as Figure 10 As described later, it is built into semiconductor device 3.

[0042] Figure 5 This is a cross-sectional view used to illustrate the relationship between the ambient light 23 and the reflected light 24 of the display panel 2 provided on the electronic device 1.

[0043] The photometer 4 of the semiconductor device 3 receives ambient light 23 that reaches the display panel 2 through the display panel 2 and reflected light 24 that is emitted from each of the light-emitting elements 17R, 17G, and 17B of the display panel 2 and reflected by the cover glass 12. Therefore, there is a problem that the ambient illuminance that is originally intended to be measured by the photometer 4 is superimposed with the illuminance of each of the light-emitting elements 17R, 17G, and 17B.

[0044] Figure 6 It is a coordinate diagram used to explain the first measurement period T1 and the second measurement period T2 of the photometer 4 installed in the semiconductor device 3. Figure 7 This is a schematic diagram illustrating the method by which measurement data measured during the first measurement period T1 is stored in the storage device 5 disposed on the semiconductor device 3. Figure 8 This is a flowchart illustrating the actions of electronic device 1.

[0045] The light measuring device 4 measures the first measurement value in a first measurement period T1 that is shorter than the on / off period T0 of each light-emitting element 17R, 17G, 17B, in sync with the vertical synchronization signal S1 (synchronization signal) of the display panel 2.

[0046] The on-off period TO includes an off period 25 in which the light emission of each light emitting element 17R, 17G, 17B is turned off and the above-mentioned on period 26 in which the light emission is turned on. In the off period 25, only the ambient light 23 from outside the display panel 2 is incident on the photometer 4. In the on period 26, the reflected light 24 based on the light emission from each light emitting element 17R, 17G, 17B is added to the ambient light 23 and is incident on the photometer 4. Figure 6 In the illustrated example, an example is shown in which the light emission of each light emitting element 17R, 17G, 17B is completely turned off in the off period 25.

[0047] Therefore, when the first measurement period Tl is included in the off period 25, only the ambient light 23 is incident on the photometer 4. When the first measurement period Tl is included in the on period 26, the reflected light 24 is added to the ambient light 23 and is incident on the photometer 4. Whether a plurality of first measurement periods Tl are included in the off period 25 or in the on period 26 can be determined based on the on-off period TO and the light emission duty ratio indicating the ratio between the off period 25 and the on period 26.

[0048] The luminance of the display panel 2 is controlled by the light emission duty ratio of each light emitting element 17R, 17G, 17B. Also, the control section 21 of the semiconductor device 3 can determine, based on a signal indicating the light emission duty ratio supplied from the display circuit 13, at which address of the first storage section 6 the first measurement value when each light emitting element 17R, 17G, 17B is turned on is stored and at which address of the first storage section 6 the first measurement value when each light emitting element 17R, 17G, 17B is turned off is stored.

[0049] In addition, Figure 6 The dotted line extending in the horizontal direction involved in the ambient light 23 indicates the level of a completely dark state in which the illuminance of the ambient light 23 is zero lux.

[0050] Also, the AD conversion circuit 20 AD-converts the first measurement value measured by the photometer 4 and supplies it to the control section 21. Next, the control section 21 stores the first measurement value supplied from the AD conversion circuit 20 in order from the beginning address of the first storage section 6 of the storage device 5.

[0051] The addresses of the first storage section 6 do not correspond to the pixels 19 of each light emitting element 17R, 17G, 17B, respectively. A larger photometer 4 is generally provided above the pixel 19 of each light emitting element 17R, 17G, 17B. The first storage section 6 stores the first measurement value corresponding to the amount of light incident on the photometer 4 regardless of the number of pixels 19.

[0052] In this way, the first storage unit 6, in sync with the vertical synchronization signal S1, sequentially writes the first measurement value from the beginning address T1 during the first measurement period. If the next vertical synchronization signal S1 is generated, the first measurement value is overwritten again from the beginning address.

[0053] For example, such as Figure 7 As shown, in the case where the first measurement period T1 synchronized with the vertical synchronization signal S1 is repeated 32 times from the 0th to the 31st, the first measurement period T1 from the 0th to the 2nd is the disconnection measurement period T4 for the light emission of each light-emitting element 17R, 17G, and 17B. Furthermore, the first measurement period T1 from the 5th to the 7th is the aforementioned light emission on-time measurement period T3. The first measurement period T1 from the 9th to the 11th is the aforementioned disconnection measurement period T4. The first measurement period T1 from the 13th to the 15th is the aforementioned on-time measurement period T3. The first measurement period T1 from the 17th to the 19th is the aforementioned disconnection measurement period T4. The first measurement period T1 from the 21st to the 23rd is the aforementioned on-time measurement period T3. The first measurement period T1 from the 25th to the 27th is the aforementioned disconnection measurement period T4. The first measurement period T1 from the 29th to the 31st is the above-mentioned light-emitting on-time measurement period T3.

[0054] Furthermore, the remaining first measurement periods T1 for the 3rd to 4th, 8th, 12th, 16th, 20th, 24th, and 28th measurements represent transition measurement periods T5 that may occur midway through the first measurement period T1, transitioning from on to off or from off to on. Therefore, the measurement values ​​of these transition periods cannot be used for calculations.

[0055] Furthermore, during a second measurement period T2, which is longer than the first measurement period T1, the photometer 4 measures a second measurement value. The AD conversion circuit 20 then performs an AD conversion on the second measurement value measured by the photometer 4 and supplies it to the control unit 21. Next, the control unit 21 stores the second measurement value supplied from the AD conversion circuit 20 in the second storage unit 7 of the storage device 5.

[0056] The second storage unit 7 stores the second measurement value measured during the second measurement period T2. Each time the measurement of the second measurement value ends, the second measurement value is overwritten in the same second storage unit 7.

[0057] Furthermore, the communication interface 22 sends the first measurement value stored in the first storage unit 6 and the second measurement value stored in the second storage unit 7 to the calculation unit 8.

[0058] Next, the calculation section 8 calculates the luminous intensity of each light emitting element 17R, 17G, 17B based on the first measurement value transmitted from the communication interface 22, and calculates the ambient light intensity by subtracting the value based on the above luminous intensity from the second measurement value transmitted from the communication interface 22.

[0059] The calculation section 8 calculates the luminous intensity of each light emitting element 17R, 17G, 17B by subtracting the first measurement value at the time when each light emitting element is off from the first measurement value at the time when each light emitting element is on based on the light emitting duty of each light emitting element 17R, 17G, 17B.

[0060] The first storage section 6 stores the measurement value obtained by adding the reflected light 24 and the ambient light 23 based on each light emitting element 17R, 17G, 17B in the first measurement period Tl. The second storage section 7 stores the measurement value obtained by adding the reflected light 24 and the ambient light 23 based on each light emitting element 17R, 17G, 17B in the second measurement period T2. Among them, the measurement value of the ambient light 23 is stored in the first measurement period Tl from the time point of the 0th to the 2nd, the 9th to the 11th, the 17th to the 19th, and the 25th to the 27th when each light emitting element 17R, 17G, 17B does not emit light.

[0061] The control section 21 decides the address information for reading out the first measurement information from the first storage section 6 in consideration of the on-off information based on the light emitting duty of each light emitting element 17R, 17G, 17B. For example, the address information that determines which address the first measurement value at the time when each light emitting element is off is stored, and which address the first measurement value at the time when each light emitting element is on is stored is decided by the control section 21.

[0062] The control section 21 reads out the first measurement value from the first storage section 6 using the above decided address information.

[0063] The control section 21 determines the address at the time when each light emitting element 17R, 17G, 17B is on by regarding the first measurement value at the time when each light emitting element is on (for example, the first measurement value of 6 addresses of the first storage section 6) as OLED_ON. Also, the control section 21 determines the address at the time when each light emitting element 17R, 17G, 17B is off by regarding the first measurement value at the time when each light emitting element is off (for example, the first measurement value of 1 address of the first storage section 6) as OLED_OFF.

[0064] The calculation section 8 preferably calculates the average value of the first measurement value read out from each address of OLED_ON of the first storage section 6. Also, the calculation section 8 preferably calculates the average value of the first measurement value read out from each address of OLED_OFF of the first storage section 6. Thereby, it is possible to obtain more stable values of OLED_ON and OLED_OFF.

[0065] The computing section 8 calculates the luminous intensity OLED_mag of each light emitting element by subtracting the first measurement value when each light emitting element 17R, 17G, 17B is off from the first measurement value when each light emitting element 17R, 17G, 17B is on, using the first measurement value when each light emitting element 17R, 17G, 17B is on and the first measurement value when each light emitting element 17R, 17G, 17B is off, through the following (Formula 1).

[0066] Further, the computing section 8 calculates the ambient illuminance through the following (Formula 2).

[0067] Ambient illuminance = second storage section measurement value - OLED_mag x (second measurement period T2 / (first measurement period T1 x 2))... (Formula 2)

[0068] Thus, the computing section 8 calculates the luminous intensity of each light emitting element 17R, 17G, 17B by subtracting the first measurement value when each light emitting element 17R, 17G, 17B is off from the first measurement value when each light emitting element 17R, 17G, 17B is on, based on the duty ratio of the light emission of each light emitting element 17R, 17G, 17B.

[0069] The on-off period TO includes the on period 26 in which each light emitting element 17R, 17G, 17B is in the on state and the off period 25 in which each light emitting element 17R, 17G, 17B is in the off state.

[0070] A part of the plurality of first measurement periods T1 is an on measurement period T3 measured in the on period 26. Another part of the plurality of first measurement periods is an off measurement period T4 measured in the off period 25. The remaining part of the plurality of first measurement periods T1 is a transition measurement period T5 in which there is a possibility of a transition from the on period 26 to the off period 25 or from the off period 25 to the on period 26.

[0071] The first storage section 6 stores the plurality of first measurement values in order from the beginning address.

[0072] Further, the computing section 8 calculates the luminous intensity of each light emitting element 17R, 17G, 17B by subtracting the first measurement value of the off measurement period T4 from the first measurement value of the on measurement period T3.

[0073] The computing section 8 calculates the ambient illuminance by subtracting a value based on the luminous intensity, the first measurement period T1, and the second measurement period T2 from the second measurement value.

[0074] Figure 8 is a flowchart showing the operation of the electronic device 1.

[0075] First, a first measurement value is measured by the light measurer 4 during a first measurement period Tl synchronized with the vertical synchronization signal S1 of the display panel 2. Also, the control section 21 sequentially stores the first measurement value from the beginning address of the first storage section 6.

[0076] Next, a second measurement value is measured by the light measurer 4 during a second measurement period T2 synchronized with the vertical synchronization signal S1. The control section 21 stores the second measurement value in the second storage section 7. The second measurement period T2 can also be a length within the interval of the vertical synchronization signal S1, or can be longer than the interval of the vertical synchronization signal S1. Generally, indoor light overlaps with fluctuations of a frequency of 100 Hz, 120 Hz, which is twice the industrial power frequency of 50 Hz, 60 Hz, and thus, if the second measurement period T2 is made 100 ms, the influence of fluctuations of this frequency can be removed.

[0077] Also, the control section 21 determines the address read from the first storage section 6 using the light emission duty of each light emitting element 17R, 17G, 17B (step Sll).

[0078] Thereafter, the control section 21 reads the first measurement value OLED_ON and the first measurement value OLED_OFF from the first storage section 6, and reads the second measurement value from the second storage section 7 (step S12).

[0079] Also, the communication interface 22 transmits the first measurement value OLED_ON, the first measurement value OLED_OFF, and the second measurement value read by the control section 21 to the calculation section 8.

[0080] Next, the calculation section 8 calculates the intensity OLED_mag of light emission of each light emitting element 17R, 17G, 17B based on the first measurement value OLED_ON and the first measurement value OLED_OFF transmitted from the communication interface 22 (step S13).

[0081] Thereafter, the calculation section 8 calculates the ambient illuminance based on the above (Equation 2) using the second measurement value transmitted from the communication interface 22 and the intensity OLED_mag of light emission of each light emitting element 17R, 17G, 17B (step S14).

[0082] Figure 9 is a block diagram of a semiconductor device 3B according to another modification. The same reference numerals are attached to the same structural elements as those described above. The detailed description of these structural elements is not repeated.

[0083] The semiconductor device 3B includes a calculation section 8. The calculation section 8 calculates the luminous intensity of each of the light emitting elements 17R, 17G, 17B based on the first measurement values stored in the first storage section 6, and calculates the ambient illuminance by subtracting a value based on the luminous intensity from the second measurement values stored in the second storage section 7. The communication interface 22 transmits the ambient illuminance calculated by the calculation section 8 to the display circuit 13 that controls the display panel 2.

[0084] In this way, the calculation section 8 can also be provided to the semiconductor device 3A instead of the display panel 2.

[0085] Figure 10 is a block diagram of a semiconductor device 3C according to still another modification. The same reference numerals are attached to the same structural elements as those described above. The detailed description of these structural elements is not repeated.

[0086] The semiconductor device 3C includes a control section 21C. The control section 21C performs the writing and reading of the measurement values to and from the storage device 5, and supplies the measurement values read from the storage device 5 to the calculation section 8. Further, the control section 21C supplies the ambient illuminance calculated by the calculation section 8 to the communication interface 22. Further, the communication interface 22 transmits the ambient illuminance calculated by the calculation section 8 to the display circuit 13 that controls the display panel 2.

[0087] [Embodiment 2]

[0088] Other embodiments of the present application are described below. Note that, for convenience of explanation, the same reference numerals are attached to structural elements having the same functions as those described in the above embodiments, and the description thereof is not repeated.

[0089] Figure 11 is a flowchart showing the operation of the electronic device according to Embodiment 2.

[0090] In Embodiment 2, the measurement values related to all the first measurement periods Tl during the period of the vertical synchronization signal S1 are read in without having the address information synchronized with the vertical synchronization signal S1, and the ambient illuminance is calculated.

[0091] First, the operation in the case where the electronic device according to Embodiment 2 includes the semiconductor device 3C in which Figure 10 the control section 21C reads in all the first measurement values from the 0th address to the 31st address in the period of the vertical synchronization signal S1 (Step S21). Further, the calculation section 8 selects the maximum value and the minimum value among all the first measurement values in the period of the vertical synchronization signal S1 (Step S22).

[0092] Next, the calculation section 8 sets the above maximum value as the first measurement value OLED_ON and sets the above minimum value as the first measurement value OLED_OFF, and based on the first measurement value OLED_ON and the first measurement value OLED_OFF, calculates the intensity OLED_mag of the light emission of each light emitting element 17R, 17G, 17B (step S23).

[0093] Thereafter, the calculation section 8 calculates the ambient illuminance based on the above (Formula 2) using the second measurement value and the intensity OLED_mag of the light emission of each light emitting element 17R, 17G, 17B (step S24).

[0094] Further, the communication interface 22 transmits the ambient illuminance calculated by the calculation section 8 to the display circuit 13 that controls the display panel 2.

[0095] In the case where the electronic device according to Embodiment 2 is provided with the semiconductor device 3B in which Figure 9 the calculation section 8 reads all the first measurement values stored in the first storage section 6. In the case where the electronic device is provided with the semiconductor device 3 in which Figure 3 the communication interface 22 reads all the first measurement values of the first storage section 6. In the case where the electronic device is provided with the semiconductor device 3A in which Figure 4 the control section 21A reads all the first measurement values of the first storage section 6.

[0096] Thus, the calculation section 8 selects the maximum value and the minimum value from among the first measurement values read from the first storage section 6, and calculates the illuminance of the light emission of each light emitting element 17R, 17G, 17B by subtracting the minimum value from the maximum value.

[0097] [Embodiment 3]

[0098] Figure 12 is a coordinate diagram for describing the operation of the electronic device according to Embodiment 3. Figure 13 is a flowchart showing the operation of the electronic device. The same reference numerals are attached to the same structural elements as those described above. The detailed description of these structural elements is not repeated.

[0099] In Embodiment 3, the method of calculating the ambient illuminance in the case where the light emission of each light emitting element 17R, 17G, 17B is not completely turned off is described.

[0100] Figure 12The illustrated example shows an example in which the light emission of each light emitting element 17R, 17G, 17B is not completely turned off during the off period 25. In this case, during the off period 25, reflected light 24 based on the light emission from each light emitting element 17R, 17G, 17B is also incident to the light measurer 4 in addition to the ambient light 23, and thus the ambient light illuminance is compensated for by a predetermined compensation coefficient based on the light that is always incident to the light measurer 4.

[0101] The electronic device according to Embodiment 3 is provided with Figure 10 The case where the semiconductor device 3C is provided with

[0102] First, a first measurement value is measured by the light measurer 4 during a first measurement period T1 synchronized with the vertical synchronization signal S1 of the display panel 2, and a second measurement value is measured by the light measurer 4 during a second measurement period T2 synchronized with the vertical synchronization signal S1. Also, the control section 21C sequentially stores the first measurement value from the beginning address of the first storage section 6, and the control section 21C stores the second measurement value in the second storage section 7. Also, the control section 21C determines the address read from the first storage section 6 using the light emission duty of each light emitting element 17R, 17G, 17B (step S31).

[0103] Thereafter, the control section 21C reads the first measurement value OLED_ON and the first measurement value OLED_OFF from the first storage section 6, and reads the second measurement value from the second storage section 7 (step S32).

[0104] Next, the calculation section 8 calculates the intensity OLED_mag of the light emission of each light emitting element 17R, 17G, 17B based on the first measurement value OLED_ON and the first measurement value OLED_OFF (step S33).

[0105] Thereafter, the calculation section 8 calculates the ambient light illuminance based on the following (Equation 3) using the second measurement value and the intensity OLED_mag of the light emission of each light emitting element 17R, 17G, 17B (step S34).

[0106] Ambient light illuminance = second storage section measurement value - OLED_mag x (second measurement period T2 / (first measurement period T1 x 2)) - compensation coefficient... (Equation 3) The above compensation coefficient is a coefficient corresponding to the light that is always incident to the light measurer 4 during both the off period 25 and the on period 26. The above compensation coefficient is a value that depends on the size of the light measurer 4 and the luminance of the display panel 2, and is a value that is determined in advance through actual measurement.

[0107] Thus, the calculation section 8 calculates the ambient illuminance based on a compensation coefficient for compensating for the influence of light that is always input to the light measurer 4 in a case where the light emission of each light emitting element 17R, 17G, 17B is not completely turned off.

[0108] [Software-based implementation example]

[0109] The functions of the calculation section 8 and the control section 21 (hereinafter referred to as "apparatus") of the electronic device 1 are programs for causing a computer to function as the apparatus, and can be implemented by programs for causing a computer to function as each control block of the apparatus.

[0110] In this case, the apparatus functions as hardware for executing the above-described programs, and includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory). By executing the above-described programs by the control device and the storage device, each function described in the above-described embodiments is implemented.

[0111] The above-described programs can also be temporary and recorded in one or a plurality of recording media that are readable by a computer. The apparatus can also include the recording media, or can not include the recording media. In the latter case, the above-described programs can also be supplied to the apparatus via any transmission medium, wired or wireless.

[0112] Furthermore, part or all of the functions of each control block can also be implemented by a logic circuit. For example, an integrated circuit formed with a logic circuit that functions as each control block is also included in the scope of the present application. Furthermore, for example, the functions of each control block can also be implemented by a quantum computer.

[0113] [Summary]

[0114] The semiconductor device 3A according to Mode 1 of the present application includes a light measurer 4 disposed on the side opposite the display surface 18 of the display panel 2 including self-light emitting elements (each light emitting element 17R, 17G, 17B) in order to measure the ambient illuminance of the display panel 2, a storage device 5 that stores a first measurement value measured by the light measurer 4 during a first measurement period T1 that is shorter than the on-off period TO of the self-light emitting elements (each light emitting element 17R, 17G, 17B) in synchronization with a synchronization signal (vertical synchronization signal S1) of the display panel 2, and a calculation section 8 that calculates the light emission illuminance of the self-light emitting elements (each light emitting element 17R, 17G, 17B) based on the first measurement value stored in the storage device 5, and calculates the ambient illuminance by subtracting a value based on the light emission illuminance from a second measurement value measured by the light measurer 4 during a second measurement period T2 that is longer than the first measurement period T1.

[0115] According to the above structure, the light measurer arranged on the side opposite to the display surface of the display panel having the self-light-emitting element measures the first measurement value in the first measurement period shorter than the on-off period of the self-light-emitting element in synchronization with the synchronization signal of the display panel. Further, the first measurement value measured by the light measurer is stored in the storage device. Next, the luminous intensity of the self-light-emitting element is calculated based on the first measurement value stored in the storage device. Thereafter, the ambient light intensity is calculated by subtracting the value based on the luminous intensity from the second measurement value measured by the light measurer in the second measurement period longer than the first measurement period.

[0116] Therefore, it is possible to accurately subtract the luminous intensity of the self-light-emitting element from the second measurement value measured by the light measurer in the second measurement period based on the synchronization signal of the display panel. As a result, it is possible to realize the semiconductor device capable of calculating more accurate ambient light intensity.

[0117] In the above-described Mode 1, the semiconductor device 3A according to Mode 2 of the present application preferably calculates the luminous intensity of the self-light-emitting element (each light-emitting element 17R, 17G, 17B) by subtracting the first measurement value at the time when the self-light-emitting element (each light-emitting element 17R, 17G, 17B) is turned off from the first measurement value at the time when the self-light-emitting element (each light-emitting element 17R, 17G, 17B) is turned on based on the light emission duty of the self-light-emitting element (each light-emitting element 17R, 17G, 17B).

[0118] According to the above structure, it is possible to accurately subtract the luminous intensity of the self-light-emitting element based on the light emission duty of the self-light-emitting element.

[0119] In the above-described Mode 1, the semiconductor device 3A according to Mode 3 of the present application preferably reads out the first measurement value stored in the storage device, selects the maximum value and the minimum value from the read-out first measurement values, subtracts the minimum value from the maximum value, and thereby calculates the luminous intensity of the self-light-emitting element.

[0120] According to the above structure, it is not necessary to have the address information of the first measurement value based on the synchronization signal of the display panel and the light emission duty of the self-light-emitting element, and therefore, it is possible to subtract the luminous intensity of the self-light-emitting element by a simple structure.

[0121] In any one of the above-described Modes 1 to 3, the semiconductor device 3A according to Mode 4 of the present application preferably calculates the ambient light intensity based on a compensation coefficient for compensating for the influence on the light always input to the light measurer 4 in the case where the light emission of the self-light-emitting element (each light-emitting element 17R, 17G, 17B) is not completely turned off.

[0122] According to the above structure, it is possible to calculate the ambient light intensity of a display panel having a self-light emitting element whose light intensity is not zero during the off period.

[0123] In the above-described mode 2, the semiconductor device 3A according to mode 5 of the present application preferably includes that the on-off period To includes the on period 26 in which the self-light emitting element (each light emitting element 17R, 17G, 17B) is in the on state and the off period 25 in which the self-light emitting element (each light emitting element 17R, 17G, 17B) is in the off state, a part of the plurality of first measurement periods Tl is the on measurement period T3 measured in the on period 26, another part of the plurality of first measurement periods Tl is the off measurement period T4 measured in the off period 25, the remaining part of the plurality of first measurement periods Tl is the transition measurement period T5 in which there is a possibility that the transition from the on period 26 to the off period 25 or from the off period 25 to the on period 26 occurs, the storage device 5 sequentially stores the plurality of first measurement values from the beginning address, and the calculation section 8 calculates the light emitting intensity of the self-light emitting element (each light emitting element 17R, 17G, 17B) by subtracting the first measurement value of the off measurement period T4 from the first measurement value of the on measurement period T3.

[0124] According to the above structure, it is possible to subtract the first measurement value when the self-light emitting element is off from the first measurement value when the self-light emitting element is on.

[0125] In the above-described mode 2, the semiconductor device 3A according to mode 6 of the present application preferably includes that the calculation section 8 calculates the ambient light intensity by subtracting a value based on the light emitting intensity, the first measurement period Tl, and the second measurement period T2 from the second measurement value.

[0126] According to the above structure, it is possible to calculate a more accurate ambient light intensity.

[0127] In any one of the above-described modes 1 to 6, the semiconductor device 3A according to mode 7 of the present application preferably includes that the storage device 5 includes the first storage section 6 that stores the first measurement value and the second storage section 7 that stores the second measurement value.

[0128] According to the above structure, it is possible to calculate the ambient light intensity based on the first measurement value stored in the first storage section and the second measurement value stored in the second storage section.

[0129] The other semiconductor device 3 according to Mode 8 of the present application includes: a light measurer 4 disposed on the side opposite the display surface 18 of the display panel 2 including self-emitting elements (the respective light emitting elements 17R, 17G, 17B) for measuring ambient illuminance of the display panel 2; a storage device 5 that stores a plurality of first measurement values measured by the light measurer 4 during a first measurement period T1 shorter than the on-off period TO of the self-emitting elements (the respective light emitting elements 17R, 17G, 17B) in synchronization with a synchronization signal (vertical synchronization signal S1) of the display panel 2; and a communication interface 22 that transmits the first measurement values and second measurement values measured by the light measurer 4 during a second measurement period T2 longer than the first measurement period T1, for calculating the luminous intensity of the self-emitting elements (the respective light emitting elements 17R, 17G, 17B) based on the first measurement values and calculating the ambient illuminance by subtracting a value based on the luminous intensity from the second measurement values.

[0130] The electronic device 1 according to Mode 9 of the present application includes: a display panel 2 including self-emitting elements (the respective light emitting elements 17R, 17G, 17B); and a semiconductor device 3 disposed on the side opposite the display surface 18 of the display panel 2, the semiconductor device 3 including: a light measurer 4 for measuring ambient illuminance of the display panel 2; a storage device 5 that stores a plurality of first measurement values measured by the light measurer 4 during a first measurement period T1 shorter than the on-off period TO of the self-emitting elements (the respective light emitting elements 17R, 17G, 17B) in synchronization with a synchronization signal (vertical synchronization signal S1) of the display panel 2; and a calculation section 8 that calculates the luminous intensity of the self-emitting elements (the respective light emitting elements 17R, 17G, 17B) based on the first measurement values stored in the storage device 5 and calculates the ambient illuminance by subtracting a value based on the luminous intensity from second measurement values measured by the light measurer 4 during a second measurement period T2 longer than the first measurement period T1.

[0131] The ambient light illuminance measuring method according to the mode 10 of the present application is an ambient light illuminance measuring method for measuring the ambient light illuminance of a display panel 2 provided with self-light emitting elements (each light emitting element 17R, 17G, 17B), including: a storing step in which a plurality of first measurement values measured by a light measurer 4 disposed on the side opposite to the display surface 18 of the display panel 2 during a first measurement period T1 shorter than the on-off period TO of the self-light emitting elements (each light emitting element 17R, 17G, 17B) in synchronization with a synchronization signal (vertical synchronization signal S1) of the display panel 2 are stored in a storage device 5; and a calculating step in which the light emitting illuminance of the self-light emitting elements (each light emitting element 17R, 17G, 17B) is calculated based on the first measurement values stored in the storage device 5, and the ambient light illuminance is calculated by subtracting a value based on the light emitting illuminance from a second measurement value measured by the light measurer 4 during a second measurement period T2 longer than the first measurement period T1.

[0132] The computer-readable recording medium according to the mode 11 of the present application records a program based on the ambient light illuminance measuring method according to the mode 10 of the present application.

[0133] The present application is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and embodiments obtained by appropriately combining the technical solutions respectively disclosed in the different embodiments are also included in the technical scope of the present application. Furthermore, by combining the technical solutions respectively disclosed in the embodiments, new technical features can be formed.

Claims

1. A semiconductor device, characterized by comprising: Possessing: a light measurer configured on the opposite side of the display surface of a display panel provided with a self-light-emitting element, for measuring ambient light intensity of the display panel; a storage device that stores a plurality of first measurement values measured by the light measurer in a plurality of first measurement periods shorter than the on-off period of the self-light-emitting element, in synchronization with a synchronization signal of the display panel; and a calculation section that calculates the light emission intensity of the self-light-emitting element based on the first measurement values stored in the storage device, and calculates the ambient light intensity by subtracting a value based on the light emission intensity from a second measurement value measured by the light measurer in a second measurement period longer than the first measurement period.

2. The semiconductor device according to claim 1, wherein the calculation section calculates the light emission intensity of the self-light-emitting element by subtracting the first measurement value when the self-light-emitting element is off from the first measurement value when the self-light-emitting element is on, based on the light emission duty ratio of the self-light-emitting element.

3. The semiconductor device according to claim 1, wherein the calculation section reads out the first measurement values stored in the storage device, selects the maximum value and the minimum value among the read-out first measurement values, and calculates the light emission intensity of the self-light-emitting element by subtracting the minimum value from the maximum value.

4. The semiconductor device according to claim 1, wherein in a case where the light emission of the self-light-emitting element is not completely off, the calculation section calculates the ambient light intensity based on a compensation coefficient for compensating for the influence of light always input to the light measurer.

5. The semiconductor device according to claim 2 or 4, wherein the on-off period includes an on period in which the self-light-emitting element is in an on state and an off period in which the self-light-emitting element is in an off state, a part of the plurality of first measurement periods is an on measurement period measured in the on period, another part of the plurality of first measurement periods is an off measurement period measured in the off period, and the remaining part of the plurality of first measurement periods is a transition measurement period in which there is a possibility of transition from the on period to the off period or from the off period to the on period, the storage device stores the plurality of first measurement values in order from a head address, and the calculation section calculates the light emission intensity of the self-light-emitting element by subtracting the first measurement value in the off measurement period from the first measurement value in the on measurement period.

6. The semiconductor device according to claim 2 or 4, wherein the calculation section calculates the ambient light intensity by subtracting a value based on the light emission intensity, the first measurement period, and the second measurement period from the second measurement value.

7. The semiconductor device according to any one of claims 1 to 4, wherein the storage device includes a first storage section that stores the first measurement values and a second storage section that stores the second measurement values. Possessing:

8. A semiconductor device, characterized by comprising: a light measurer configured on the opposite side of the display surface of a display panel provided with a self-light-emitting element, for measuring ambient light intensity of the display panel; ​ a storage device that stores a plurality of first measurement values measured by the light measurement device in a first measurement period shorter than the on-off period of the self-light-emitting element in synchronization with a synchronization signal of the display panel; and a communication interface that transmits the first measurement values and second measurement values, calculates an emission luminance of the self-light-emitting element based on the first measurement values, and calculates the ambient light illuminance by subtracting a value based on the emission luminance from second measurement values measured by the light measurement device in a second measurement period longer than the first measurement period.

9. An electronic device, comprising: including: a display panel including a self-light-emitting element; and a semiconductor device disposed on the side opposite to the display surface of the display panel, the semiconductor device including: a light measurement device for measuring an ambient light illuminance of the display panel; a storage device that stores a plurality of first measurement values measured by the light measurement device in a first measurement period shorter than the on-off period of the self-light-emitting element in synchronization with a synchronization signal of the display panel; and a calculation unit that calculates an emission luminance of the self-light-emitting element based on the first measurement values stored in the storage device, and calculates the ambient light illuminance by subtracting a value based on the emission luminance from second measurement values measured by the light measurement device in a second measurement period longer than the first measurement period.

10. An ambient light illuminance measurement method for measuring an ambient light illuminance of a display panel including a self-light-emitting element, the ambient light illuminance measurement method characterized by comprising: a storage process in which a plurality of first measurement values measured by a light measurement device disposed on the side opposite to the display surface of the display panel in a first measurement period shorter than the on-off period of the self-light-emitting element are stored in a storage device in synchronization with a synchronization signal of the display panel; and a calculation process in which an emission luminance of the self-light-emitting element is calculated based on the first measurement values stored in the storage device, and the ambient light illuminance is calculated by subtracting a value based on the emission luminance from second measurement values measured by the light measurement device in a second measurement period longer than the first measurement period.

11. A computer-readable recording medium characterized by having recorded a program based on the ambient light illuminance measurement method according to claim 10.

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