Patent Description:
According to the increasing human life-span, it has been considered important to develop smart health-care sensors which may periodically and concisely check a variety of biometric signals or health information in daily life, without having to visit a medical center.

Recently, a function to sense and monitor biometric data has been added to accessories such as smart phones and/or smart bands, and ways to variously utilize the biometric data have been steadily researched. In some cases, conventional large-scale medical equipment for measuring and collecting concise biometric data may be down-sized, but performance of the medical equipment has to be maintained regardless of the downsizing.

A pulse oximeter may sense both a heart rate and oxygen saturation of blood at the same time in a non-invasive way, and has a merit of downsizing, so it has been employed for many products. If information (e.g., biometric data) of the heart rate and the oxygen saturation of blood is easily measured and accumulated, it may be usefully utilized for preventing a disease based on health data such as that of a circulatory system and pulmonary function. The conventional pulse oximeter generally includes two LEDs and one photodiode. The LED is selected to have a selective light emitting characteristic of a narrow width in each wavelength of a red region and a green region, each LED is caused to emit light in one cycle, and an optical signal obtained in a photodiode based on transmission of the emitted light through a blood vessel and to the photodiode is analyzed to determine heart rate and oxygen saturation.

Recently, various attempts to provide a flexible pulse oximeter have been performed for applying the same to a portable accessory. (<CIT> or <NPL>,.

However, a photodiode used for the pulse oximeter which has been developed so far depends upon wavelength separation of an LED light source.

Particularly, to compensate for the use of a photodiode having insufficient sensitivity and to obtain a concise optical signal from light transmitted through skin and passed through a blood vessel, the intensity of the light source should be sufficient. However, such a light source may cause burning of skin or damage to tissue of patients or subjects based on emitting light having sufficient intensity to enable the photodiode to obtain a concise optical signal based on the light being transmitted through skin and passed through a blood vessel and further to the photodiode.

In addition, the conventional medical sensors, as disclosed in <CIT>, use a lead wire which is not flexible, so a life-span of the sensor is determined by the same.

<CIT> discloses a wearable biometric device including a biometric system adapted to measure a physiological property of a user's body at two or more different locations at the body surface.

<CIT> discloses a spectrophotometric sensor for pulse oximetry having a broadband emitter and a sensor that includes infrared and red photodetectors.

<CIT> discloses a photoelectric converter including an organic photoelectric conversion section, an inorganic photoelectric conversion section, and an optical filter.

According to an aspect of the invention, there is provided a pulse oximeter according to claim <NUM>.

Pulse oximeters employing a photoelectric conversion device having wavelength selectivity are provided, so a low output LED may be employed for preventing skin damage and reducing power consumption of the pulse oximeters.

The pulse oximeters may be sufficiently down-sized to be applicable for a portable device. Put another way, embodiments may enable a reduction in size of a pulse oximeter so as enable use in/with a portable device.

The pulse oximeters may be formed with ("may at least partially comprise") an organic material, so they may be provided in a wearable manner.

Pulse oximeter-embedded near infrared organic image sensors which may be mounted in a variety of portable devices such as a smart phone are provided.

According to some example embodiments, by employing the photoelectric conversion device having wavelength selectivity, a low output LED may be employed for preventing skin damage and reducing power consumption.

It may be sufficiently downsized to be applicable for a portable device.

It is formed with an organic material, so may be provided in a wearable device.

The pulse oximeter may be embedded in an image sensor for a variety of portable devices such as a smart phone.

The light emitting device may be configured to emit white light having an intensity of about <NUM> to about <NUM> mW.

The red photoelectric conversion device may be an organic red photoelectric conversion device. The organic red photoelectric conversion device may be between a semiconductor substrate and the near infrared organic photoelectric conversion device.

The red photoelectric conversion device may be an inorganic red photoelectric conversion device embedded in a semiconductor substrate.

The inorganic red photoelectric conversion device may include an array of a plurality of inorganic red photoelectric conversion elements. Each inorganic red photoelectric conversion element of the plurality of inorganic red photoelectric conversion elements may define a separate unit pixel.

The pulse oximeter may further include a signal processor configured to calculate a heart rate and oxygen saturation based on a determination of an absorbance of near infrared light that is measured by the near infrared organic photoelectric conversion device based on at least a portion of the transmitted light in the particular near infrared wavelength spectrum being absorbed by the near infrared organic photoelectric conversion device, and an absorbance of red light that is measured by the red photoelectric conversion device based on at least a portion of the transmitted light in the particular red wavelength spectrum being absorbed by the red photoelectric conversion device.

Hereinafter, the present disclosure will be described more fully with reference to the accompanying drawings, in which some example embodiments of the disclosure are shown.

<FIG> is a schematic view showing a pulse oximeter according to some example embodiments of the present inventive concepts.

Referring to <FIG>, the pulse oximeter <NUM> includes a power source <NUM>, a light emitting device <NUM>, a sensor <NUM>, a signal processor <NUM>, and a communication interface device <NUM>.

The power source <NUM> supplies power to the light emitting device <NUM>, the sensor <NUM>, the signal processor <NUM>, and the communication interface device <NUM>, and it may be provided as an ultra-small battery or a flexible battery and the like in a case of a portable device.

The light emitting device <NUM> may be provided as one white light emitting diode (LED) only. As referred to herein, a white LED may be configured to emit "white light," where "white light" may be understood to be light that is a combination of light of different wavelengths in the visible wavelength spectrum (between about <NUM> and about <NUM>). For example, white light may include a combination of "red light," "green light," and "blue light," where red light includes light in a red wavelength spectrum of about <NUM> to about <NUM>, green light includes light in a green wavelength spectrum of about <NUM> to about <NUM>, and blue light includes light in a blue wavelength spectrum of about <NUM> to about <NUM>. The white LED may either be an inorganic LED or an organic LED, but the organic LED may be more appropriate to accomplish a flexible device. As the conventional pulse oximeter uses only a photodiode having no wavelength selectivity, the wavelength of emitted light may be divided in the light emitting device <NUM>. As a result, the light emitting device <NUM> includes an LED having a light emitting characteristic selective to a red region ("red wavelength spectrum") and an LED having a light emitting characteristic selective to a near infrared region ("near infrared wavelength spectrum") or a green region ("green wavelength spectrum"), and in order to compensate the sensitivity of the insufficiently sensitive photodiode, the light intensity of the light source may be increased up to around <NUM>-<NUM> mW to emit light, which may result in tissue damage (e.g., skin damage) based on the intensity of the emitted light passing through human tissue. However, in the pulse oximeter according to some example embodiments of the present disclosure, the sensor <NUM>, which is described later, has wavelength selectivity (e.g., is configured to sense light in one or more particular limited wavelength spectra), so it is sufficient for the light emitting device <NUM> to include only a white LED configured to emit white light, and it is also sufficient to emit the white light of the white LED light source of a low intensity of about <NUM>-<NUM> mW, which is sufficiently low intensity of emitted white light to at least partially mitigate the risk of tissue damage resulting from the emitted white light passing through human tissue and/or a blood vessel to reach the sensor <NUM>. Additionally, because the white LED may only emit white light at a lower intensity of about <NUM>-<NUM> mW, power consumption of the pulse oximeter <NUM> may be reduced without reducing capability of the device to implement pulse oximetry, thereby improving performance of the device.

When the terms "around," "about," or "substantially" are used in this specification in connection with a numerical value, it is intended that the associated numerical value include a tolerance of ±<NUM>% around the stated numerical value. When ranges are specified, the range includes all values therebetween such as increments of <NUM>%.

The sensor <NUM> includes a near infrared organic photoelectric conversion device <NUM> and a red photoelectric conversion device <NUM>. The sensor <NUM> is configured to detect transmitted light, of the white light that is emitted by the light emitting device <NUM>, subsequently to the transmitted light having irradiated a blood vessel. As shown in <FIG>, the near organic photoelectric conversion device <NUM> is configured to sense and/or absorb light in a particular, limited, near infrared wavelength spectrum <NUM> (e.g., "near infrared light"), and the red photoelectric conversion device <NUM> is configured to sense and/or absorb light in a particular, limited, red wavelength spectrum <NUM> (e.g., "red light"), such that the sensor <NUM> is configured to have wavelength selectivity so it is sufficient for the light emitting device <NUM> to include only a white LED configured to emit white light, and it is also sufficient to emit the white light of the white LED light source of a low intensity of about <NUM>-<NUM> mW. As shown in <FIG>, the near infrared organic photoelectric conversion device <NUM> may be proximate to an incident light side <NUM> of the sensor <NUM>, such that incident light that is incident on the sensor <NUM> via the incident light side <NUM> must pass through the near infrared organic photoelectric conversion device <NUM> to be incident on the red photoelectric conversion device <NUM>. The red photoelectric conversion device <NUM> may be between the near infrared organic photoelectric conversion device <NUM> and a substrate <NUM>. In some example embodiments, the near infrared organic photoelectric conversion device <NUM> may be between the red photoelectric conversion device <NUM> and the incident light side <NUM> of the sensor <NUM>. In some example embodiments, the red photoelectric conversion device <NUM> may be between the near infrared organic photoelectric conversion device <NUM> and the incident light side <NUM> of the sensor <NUM>.

Referring to <FIG>, the external quantum efficiency (EQE) of the near infrared organic photoelectric conversion device <NUM> is relatively high in the near infrared wavelength spectrum <NUM> of light that the near infrared organic photoelectric conversion device <NUM> is configured to sense and/or absorb, and the external quantum efficiency of the red photoelectric conversion device <NUM> is relatively high in the red wavelength spectrum <NUM> of light that the red photoelectric conversion device <NUM> is configured to sense (e.g., absorb). Meanwhile, looking at the molar extinction coefficient of oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb), the oxyhemoglobin (HbO2) has a relatively higher molecule extinction coefficient than the deoxyhemoglobin (Hb) in the near infrared ray region (e.g., near infrared wavelength spectrum <NUM>), and the deoxyhemoglobin (Hb) has a relatively higher extinction coefficient than the oxyhemoglobin (HbO2) in the red wavelength spectrum <NUM>.

Accordingly, referring to <FIG> again, the signal processor <NUM> may calculate a Hb/HbO2 concentration ratio based on an absorbance of near infrared light (e.g., light in the near infrared wavelength spectrum <NUM>) that is measured by the near infrared organic photoelectric conversion device <NUM> of the sensor <NUM> based on at least a portion of incident light (e.g., transmitted light that is emitted by the light emitting device <NUM> and irradiates a blood vessel and is subsequently received by the sensor <NUM>) in the particular near infrared wavelength spectrum (e.g., wavelength spectrum <NUM>) being absorbed by the near infrared organic photoelectric conversion device <NUM> and an absorbance of red light (e.g., light in the red wavelength spectrum <NUM>) that is measured by the red photoelectric conversion device <NUM> of the sensor <NUM> based on at least a portion of incident light (e.g., transmitted light that is emitted by the light emitting device <NUM> and irradiates a blood vessel and is subsequently received by the sensor <NUM>) in the particular red wavelength spectrum (e.g., wavelength spectrum <NUM>) being absorbed by the red photoelectric conversion device <NUM>, and may then calculate oxygen saturation using the same. In addition, the signal processor <NUM> may calculate a heart rate through a waveform shown in the measurement.

The signal digitalized in the signal processor <NUM> may transmit the measured oxygen saturation and pulse signals to an external remote processing device (ex. , a smart phone, a remote monitoring device, etc.) through the communication interface device <NUM>. The communication interface device <NUM> may communicate by wire, or may communicate by near field wireless communication such as Bluetooth, ZigBee, UWB (Ultra Wide Band), IEEE <NUM> based Wi-Fi, and the like.

As shown in <FIG>, the near infrared organic photoelectric conversion device <NUM> and the red photoelectric conversion device <NUM> for the sensor <NUM> may be laminated. In some example embodiments, the red photoelectric conversion device <NUM> may also be formed of ("may at least partially comprise") an organic material as is the near infrared organic photoelectric conversion device <NUM>. When the photoelectric conversion devices <NUM> and <NUM> are formed only of organic materials as above, it is easy for them to be fabricated with a flexible substrate. Accordingly, it may be applicable for a wearable pulse oximeter such as a disposable or patch-type pulse oximeter. In some example embodiments, a flexible display <NUM> may also be mounted in the pulse oximeter so that the results are directly shown without transmitting the same to an external display through the communication interface device <NUM>. Restated, the flexible display <NUM> may be configured to display a signal of the sensor <NUM>.

<FIG> is a schematic view showing a patch-type pulse oximeter <NUM> embodying a pulse oximeter <NUM> according to some example embodiments of the present inventive concepts. The pulse oximeter <NUM> shown in <FIG> may be the pulse oximeter <NUM> shown in <FIG>. The patch-type pulse oximeter <NUM> may be a wearable pulse oximeter that includes a wearable strap <NUM> that is configured to be attached to a portion of a human body, and wherein one or more portions of the pulse oximeter <NUM> are incorporated into the wearable strap <NUM>.

The pulse oximeter <NUM> may include a white LED <NUM> and a sensor <NUM> in which a near infrared organic photoelectric conversion device <NUM> and a red organic photoelectric conversion device <NUM> are stacked on a patch-type flexible substrate <NUM>. Accordingly, it will be understood that the sensor <NUM> may include a "stack" of a near infrared organic photoelectric conversion device <NUM> and a red organic photoelectric conversion device <NUM>. When the signal measured by the sensor <NUM> is transmitted via a wire <NUM> as shown in <FIG>, the signal processor <NUM> or the communication interface device <NUM> may be omitted from the pulse oximeter <NUM> shown in <FIG>.

As shown in <FIG>, the red organic photoelectric conversion device <NUM> may be between the near infrared organic photoelectric conversion device <NUM> and a semiconductor substrate <NUM>, such that the red organic photoelectric conversion device <NUM> is distal from a light incident side of the sensor <NUM> in relation to the near infrared organic photoelectric conversion device <NUM>, but example embodiments are not limited thereto. For example, in some example embodiments, the near infrared organic photoelectric conversion device <NUM> may be between the red organic photoelectric conversion device <NUM> and a substrate <NUM>, such that the near infrared organic photoelectric conversion device <NUM> is distal from a light incident side of the sensor <NUM> in relation to the red organic photoelectric conversion device <NUM>.

<FIG> shows a pulse oximeter according to some example embodiments of the present disclosure. Referring to <FIG>, unlike the sensor <NUM> of the pulse oximeter shown in <FIG>, the sensor <NUM> includes a near infrared organic photoelectric conversion device <NUM> and an inorganic red photoelectric conversion device <NUM> under the same (e.g., between the near infrared organic photoelectric conversion device <NUM> and a substrate). The lower inorganic red photoelectric conversion device <NUM> may be at least partially formed in (e.g., embedded in) a semiconductor substrate, for example, a silicon substrate, such that the lower inorganic red photoelectric conversion device <NUM> is at least partially located within a volume that is defined by outer surfaces of the semiconductor substrate. The inorganic red photoelectric conversion device <NUM> includes an array of a plurality of inorganic red photoelectric conversion devices, and each inorganic red photoelectric conversion device <NUM> may define a separate unit pixel PX. In some example embodiments, the near infrared organic photoelectric conversion device <NUM> may be between the inorganic red organic photoelectric conversion device <NUM> and a substrate, such that the near infrared organic photoelectric conversion device <NUM> is distal from a light incident side of the sensor <NUM> in relation to the inorganic red organic photoelectric conversion device <NUM>.

When the lower inorganic red photoelectric conversion device <NUM> is formed with an array of a plurality of red pixels, it may provide the heart rate and the oxygen saturation for the subject with pixelated information. Restated, the inorganic red photoelectric conversion device <NUM> may include an array of a plurality of inorganic red photoelectric conversion elements <NUM>-<NUM> to <NUM>-N (N being a positive integer), and each inorganic red photoelectric conversion element (also referred to herein as a inorganic red photoelectric conversion device) of the plurality of inorganic red photoelectric conversion elements <NUM>-<NUM> to <NUM>-N may define a separate unit pixel PX. In some example embodiments, it may be applicable for a pulse oximeter and a camera for a medical purpose such as a surgery, so as to provide information on blood flow trouble and a damage condition of a certain blood vessel in the surgical site through concise pulse mapping. In addition, it may help to prevent additional damage of a region that is not yet damaged through a high resolution image of a blood vessel. Furthermore, by using the high resolution high efficient stacked pulse oximeter, it may be applied for an angiography apparatus ("angiographic device") configured to diagnose and treat with a laser through precise blood vessel imaging even without surgery.

<FIG> is a schematic view showing a pulse oximeter-embodied image sensor <NUM> according to some example embodiments of the present disclosure, and <FIG> is a schematic view showing a pixel array of the pulse oximeter-embodied image sensor <NUM>.

Referring to <FIG> and <FIG>, the image sensor <NUM> includes an inorganic photoelectric conversion device <NUM> that includes an array of photoelectric conversion devices 550r, <NUM>, and 550b formed in ("embedded in") a semiconductor substrate <NUM>, such that the photoelectric conversion devices 550r, <NUM>, and 550b are located within a volume space that is defined by the semiconductor substrate <NUM>, as shown in at least <FIG>, and a near infrared organic photoelectric conversion device <NUM> formed thereon ("on the array of photoelectric conversion devices 550r, <NUM>, and 550b").

The plurality of inorganic photoelectric conversion devices are formed with particular (or, alternatively, predetermined) alignment in a particular (or, alternatively, predetermined) region of the semiconductor substrate <NUM>. The inorganic photoelectric conversion device <NUM> may include a red photoelectric conversion device 550r, a green photoelectric conversion device <NUM>, and a blue photoelectric conversion device 550b. It will be understood that, just as a red photoelectric conversion device 550r is configured to selectively absorb light having a red wavelength spectrum ("red light"), the green photoelectric conversion device <NUM>, and the blue photoelectric conversion device 550b are configured to selectively absorb light having a green wavelength spectrum ("green light") and light having a blue wavelength spectrum ("blue light"), respectively.

In some example embodiments, including the example embodiments shown in <FIG>, the red photoelectric conversion device 550r, the green photoelectric conversion device <NUM>, and the blue photoelectric conversion device 550b may be disposed as a Bayer array, but of course the alignment may be variously changed.

The near infrared organic photoelectric conversion device <NUM> is formed of a combination of a near infrared organic photoelectric conversion layer <NUM> on the semiconductor substrate <NUM> and a common electrode <NUM> disposed on the near infrared organic photoelectric conversion layer <NUM>, and a pixel electrode <NUM> formed for each separate pixel under the same such that each pixel electrode <NUM> is between the near infrared organic photoelectric conversion layer <NUM> and the semiconductor substrate <NUM> and, as shown in <FIG>, each separate unit pixel PX of the image sensor <NUM> includes a separate photoelectric conversion device 550r, <NUM>, 550r and a separate pixel electrode <NUM> overlapped with a separate portion of the near infrared organic photoelectric conversion layer <NUM> and the common electrode <NUM>. The near infrared organic photoelectric conversion layer <NUM> may be configured to absorb the particular near infrared wavelength spectrum <NUM>. Each pixel electrode <NUM> is connected with a charge accumulator <NUM> through a contact <NUM> filled in a via formed in an interlayer insulating layer <NUM>.

A flat layer <NUM> that is transparent to incident light is formed on the common electrode <NUM>. A microlens <NUM> is formed to focus the incident light onto each pixel in a site corresponding to each pixel. As shown in <FIG>, side 501A of the image sensor <NUM> may be a light incident side, such that the near infrared organic photoelectric conversion device <NUM> is proximate to the light incident side 501A in relation to the array of photoelectric conversion devices 550r, <NUM>, and 550b. But, in some example embodiments, side 501B of the image sensor <NUM> may be a light incident side, such that the near infrared organic photoelectric conversion device <NUM> is distal to the light incident side 501B in relation to the array of photoelectric conversion devices 550r, <NUM>, and 550b.

<FIG> is a schematic view showing a readout circuit of the pulse oximeter-embedded image sensor <NUM> according to some example embodiments.

A charge accumulated in the inorganic photoelectric conversion devices 550r, <NUM>, and 550b and a charge accumulated in the charge accumulator <NUM> are sensed using a readout circuit including a transistor having a <NUM>-transistor structure or a <NUM>-transistor structure, and the like. <FIG> shows an example of an inorganic red photoelectric conversion device 550r, but it is equivalently applicable to an inorganic green photoelectric conversion device <NUM> and an inorganic blue photoelectric conversion device 550b.

Referring to <FIG>, a charge accumulated in the inorganic red photoelectric conversion device 550r is read out by a reset transistor Tr1 having a drain connected to the inorganic red photoelectric conversion device 550r and a source connected to a power source Vn, an output transistor Tr2 having a gate connected to the drain of the reset transistor Tr1 and a source connected to the power source Vcc, and a row selective transistor Tr3 having a source connected to the drain of the output transistor Tr2 and a drain connected to the signal output line <NUM>.

The charge detected by the near infrared organic photoelectric conversion device <NUM> and accumulated in the charge accumulator <NUM> is read out by a reset transistor Tr1 having a drain connected to the charge accumulator <NUM> and a source connected to a power source Vcc, an output transistor Tr2 having a gate connected to the drain of the reset transistor Tr1 and a source connected to the power source Vcc, and a row selective transistor Tr3 having a source connected to the drain of the output transistor Tr2 and a drain connected to the signal output line <NUM>.

A charge generated and stored in the inorganic red photoelectric conversion device 550r is converted to a signal corresponded to an amount of charge through an output transistor Tr2. When the row selective transistor Tr3 is turned on, the signal is output to the signal output line <NUM>. After outputting the signal, the charge of the inorganic red photoelectric conversion device 550r is reset by the reset transistor Tr1. If required, it may further include a delivering transistor (not shown) between the inorganic red photoelectric conversion device 550r and the drain of the reset transistor Tr1.

When a bias voltage is applied between the pixel electrode <NUM> and the common electrode <NUM>, a charge is generated corresponding to light having entered the near infrared organic photoelectric conversion layer <NUM> and is transported to the charge accumulator <NUM> through a contact <NUM> connected with the pixel electrode <NUM>. The charge stored in the charge accumulator <NUM> is converted to a signal corresponding to an amount of charge through the output transistor Tr2. When the row selective transistor Tr3 is turned on, the signal is output to the signal output line <NUM>. After outputting the signal, the charge of the charge accumulator <NUM> is reset by the reset transistor Tr1. If required, it may further include a delivery transistor (not shown) between the charge accumulator <NUM> and the drain of the reset transistor Tr1.

The signal output through the two signal output lines <NUM> and <NUM> is transmitted to a signal processor <NUM>, and a heart rate and oxygen saturation are calculated based on the data transmitted from the signal processor <NUM>. The operation corresponds to a case of a pulse oximetry mode. In a case of a camera mode, all signals of the inorganic red photoelectric conversion device 550r, the inorganic blue photoelectric conversion device 550b, the inorganic green photoelectric conversion device <NUM>, and the signal of the near infrared organic photoelectric conversion device <NUM> are output, and an image signal may be finally output from the signal processor <NUM>. Needless to say, the two modes may be simultaneously performed, if required.

When using the pulse oximeter-embedded image sensor <NUM> shown in <FIG> and <FIG>, it has a merit of simultaneously or selectively performing a camera mode using a general image sensor and the pulse oximetry mode. In other words, as required, only the camera mode may be operated, only the pulse oximeter may be operated, or both the camera mode and the pulse oximetry mode may be simultaneously operated.

Thus as shown in <FIG>, the pulse oximeter <NUM> and a rear camera <NUM>, which used to be separately mounted in a mobile device 800A such as a smart phone, may be integrated into one camera <NUM>. It may further include a light emitting device <NUM> on one side of the camera <NUM> of a mobile device 800B such as a smart phone, so as to emit white light and to irradiate the same to a blood vessel.

Claim 1:
A pulse oximeter, comprising:
a light emitting device (<NUM>) configured to emit white light to irradiate a blood vessel; and
a sensor (<NUM>) comprising separate unit pixels (PX) and configured to detect transmitted light that is received from the light emitting device, subsequently to the transmitted light having irradiated the blood vessel, the sensor including
a near infrared organic photoelectric conversion device (<NUM>) configured to sense a particular near infrared wavelength spectrum of light, and
a red photoelectric conversion device (<NUM>) configured to sense a particular red wavelength spectrum of light,
characterized in that:
the near infrared organic photoelectric conversion device (<NUM>) is formed of a combination of a near infrared organic photoelectric conversion layer (<NUM>) on a semiconductor substrate (<NUM>) and a common electrode (<NUM>) disposed on the near infrared organic photoelectric conversion layer (<NUM>), and a pixel electrode (<NUM>) formed for each separate unit pixel is between the near infrared organic photoelectric conversion layer (<NUM>) and the semiconductor substrate (<NUM>) and in contact with the near infrared organic photoelectric conversion layer (<NUM>);
each separate unit pixel (PX) includes a separate photoelectric conversion device (550r, <NUM>, 550r) and a separate pixel electrode (<NUM>) overlapped with a separate portion of the near infrared organic photoelectric conversion layer (<NUM>) and the common electrode (<NUM>); and
each pixel electrode (<NUM>) is connected with a charge accumulator (<NUM>) through a contact (<NUM>) filled in a via formed in an interlayer insulating layer (<NUM>).