KR101090968B1 - Photographing apparatus having image sensor - Google Patents

Abstract

The present invention relates to a photographing apparatus including an image sensor, and discloses a technology for simplifying and miniaturizing a system by incorporating a light emitting diode (LED) control function in an image sensor. The present invention includes an illumination sensor for sensing brightness information, an image sensor for capturing an image and outputting an image signal, and a light emitting unit operating under control of the image sensor and operating in response to the level of the brightness information. The image sensor includes signal processing means for signal processing brightness information applied from the illuminance sensor. Accordingly, the present invention simplifies the system by incorporating a processing circuit capable of processing brightness information sensed from the illuminance sensor in the image sensor and a control function of a light emitting diode (LED) according to the signal level of the illuminance sensor. Miniaturization and system cost can be reduced.

Image, Sensor, LED, IR, ADC

Description

Shooting apparatus including an image sensor {PHOTOGRAPHING APPARATUS HAVING IMAGE SENSOR}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing apparatus including an image sensor, and more particularly to an image sensor for converting an external optical image signal into an electrical image signal.

In general, an image sensor is a device that converts an external optical image signal into an electrical image signal. In particular, CMOS image sensors are image sensors fabricated using CMOS fabrication techniques. In the CMOS image sensor, each pixel stores the light signal radiated from the corresponding part of the object after converting it into electrons using a photodiode, and converts the amount of charge appearing in proportion to the accumulated number of electrons into a voltage signal and outputs the voltage signal. Use

Image sensors are largely divided into CMOS image sensors using complementary-MOS (CMOS) technology and CCD image sensors using Charge Coupled Device (CCD) technology, all of which are manufactured using semiconductor technology.

Such a CMOS image sensor is a device widely used in various electronic products, for example, a mobile phone, a camera for a personal computer (PC), a video camera, and a digital camera.

The CMOS image sensor is simpler to drive than the CCD used as an image sensor, and it is possible to integrate a signal processing circuit into one chip so that a system on chip (SoC) can be used to make the module smaller. Let's do it. In addition, since the conventional set-up (CMOS) technology can be used interchangeably, there are many advantages such as lowering the manufacturing cost, so the demand is increasing rapidly.

In general, a photographing apparatus including an image sensor such as a digital camera, a camcorder, and a portable terminal in which a camera function is implemented, acquires an image signal by capturing an image input through a lens with an image sensor. The video signal is converted into digital video data and displayed on a liquid crystal screen as a preview screen. When the user presses the shutter key while the preview image is displayed, the image data is compressed and stored as photo data.

1 is a block diagram of a photographing apparatus including a conventional image sensor.

The conventional photographing apparatus includes an illuminance sensor 1, a micro controller unit (MCU) 10, a light emitting element 20, and an image sensor 30. Here, the microcontroller unit 10 includes an analog digital converter (ADC) 11. In addition, the light emitting device 20 may include a light emitting diode (LED) or an infrared (IR) light emitting diode (LED).

First, the illuminance sensor 1 detects ambient brightness information, and the brightness information detected by the illuminance sensor 1 is input to the microcontroller unit 10. The analog-to-digital converter 11 provided in the microcontroller unit 10 converts an analog signal for brightness information applied from the illuminance sensor 1 into a digital signal.

The micro controller unit 10 controls the brightness information applied from the illuminance sensor 1 to control the turn on or turn off operation of the light emitting device 20. In addition, the microcontroller unit 10 is connected to the image sensor 30 through a specific communication bus, for example, an I 2 C (Inter Integrated Circuit). The image sensor 30 outputs an analog or digital video signal by photographing a subject under the control of the microcontroller unit 10.

Recently, in the terminal market, LEDs or IR LEDs are used as essential elements to improve low light sensitivity of cameras used in surveillance or door locks. That is, the illumination sensor 1 is used to control the light emitting device 20 according to the illumination of the surrounding environment.

However, the conventional photographing apparatus includes a microcontroller 10 having an analog-digital converter 11 embedded therein separately from the image sensor 30 to perform signal processing by receiving the sensing result of the illuminance sensor 1. . Accordingly, not only the cost of implementing the photographing system including the image sensor increases, but also the volume of the system becomes large.

In order to solve the above-mentioned problems, the present invention provides a processing circuit capable of processing brightness information detected from an illuminance sensor in an image sensor, and a light emitting diode (LED) control function according to a signal level of the illuminance sensor. The purpose is to simplify the system, reduce the cost, and reduce the cost of the system.

The imaging apparatus including the image sensor of the present invention for achieving the above object, the illumination sensor for sensing the brightness information; An image sensor which takes an image and outputs an image signal; A light emitting unit operating under the control of the image sensor and operating in correspondence with the level of brightness information; And an encoder for encoding a video signal applied from an image sensor and outputting a video signal, wherein the image sensor includes signal processing means for signal processing brightness information applied from the illuminance sensor, and includes an initialization setting information stored in a register. According to the present invention.

The present invention simplifies the system by incorporating a light emitting diode (LED) control function in the image sensor.

In addition, the present invention provides an effect of minimizing the system and reducing the unit price by performing the initialization setting of the encoder chip and the LED control function using only the image sensor without using a separate microcontroller unit.

In addition, the preferred embodiment of the present invention is for the purpose of illustration, those skilled in the art will be able to various modifications, changes, substitutions and additions through the spirit and scope of the appended claims, such modifications and modifications are the following patents It should be regarded as belonging to the claims.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a photographing apparatus including an image sensor according to the present invention.

The present invention includes an illuminance sensor 100, a register 200, an image sensor 300, a light emitting unit 400, and an encoder 500. The image sensor 300 includes an analog digital converter 310, which is a signal processing means, an internal logic controller 320, a light emission controller 330, and a lens 340. The light emitting unit 400 may include a light emitting device such as a light emitting diode (LED) or an infrared light emitting diode (IR).

First, the illuminance sensor 100 detects surrounding brightness information and outputs the brightness information to the image sensor 300. In addition, the brightness information detected by the illuminance sensor 100 is input to the analog-digital converter 310 provided in the image sensor 300. Then, the analog-to-digital converter 310 provided inside the image sensor 300 converts an analog signal for brightness information applied from the illumination sensor 100 into a digital signal.

The internal logic controller 320 controls an image signal of a subject photographed from the lens 340 according to a digital signal or an internal control signal applied from the analog-digital converter 310 and outputs the digital signal D_OUT. The internal logic controller 320 outputs the digital signal applied from the analog to digital converter 310 to the light emission controller 330.

In addition, the internal logic controller 320 controls the initialization setting operation of the encoder 500 according to the initialization setting value read from the register 200.

The light emission controller 330 controls the brightness information applied from the illumination sensor 100 through the analog-to-digital converter 310 and the internal logic controller 320 to emit light provided in the light emission unit 400 according to the illumination level. Selectively control the turn on or turn off operation of the device.

In addition, the image sensor 300 is connected to an external register 200 through a specific communication bus B1 and is connected to an external encoder 500 through a specific communication bus B2. Here, it is preferable that the specific communication buses B1 and B2 consist of an Inter Integrated Circuit (I2C) bus. In addition, in the present invention, the specific communication buses B1 and B2 are configured as I2C buses, but the present invention is not limited thereto, and the specific communication buses may be configured as SPI (Serial Peripheral Interface) buses.

The register 200 stores operation information for controlling the turn on or turn off operation of the light emitting unit 400. Accordingly, the internal logic controller 320 of the image sensor 300 outputs an operation control signal for controlling the operation of the light emitter 400 to the light emission controller 330 based on the operation information read from the register 200. . Here, the register 200 is preferably made of a nonvolatile memory such as an electrically erasable programmable read-only memory (EEPROM).

In addition, the encoder 500 encodes the digital signal D_OUT applied from the image sensor 300 to output the analog video signal OUT.

3 is a detailed circuit diagram of the illuminance sensor 100 of FIG. 2.

The illuminance sensor 100 includes resistors R1 and R2, a capacitor C1, and a sensing unit 101. Here, the resistors R1 and R2 and the sensing unit 101 are connected in series between the supply terminal VCC and the ground terminal. The capacitor C1 is connected in parallel with the resistor R2.

The illumination sensor 100 having such a configuration is connected to the analog-digital converter 310 and the input pin 301 provided in the image sensor 300. Here, the input pin 301 is provided in the input pad area of the image sensor 300 to transmit a signal for the brightness information applied from the illumination sensor 100 to the analog-to-digital converter 310.

4 is a detailed circuit diagram illustrating the light emitting unit 400 of FIG. 2.

The light emitting unit 400 includes resistors R3 and R4, a transistor T1, and a plurality of light emitting devices 410 and 420. Here, the resistor R4, the plurality of light emitting devices 410 and 420, and the transistor T1 are connected in series between a power supply voltage VCC applying terminal and a ground terminal.

The transistor T1 is controlled to be turned on or turned off according to a control signal applied from the light emission controller 330 of the image sensor 330 through the resistor R3. Here, the transistor T1 is preferably made of a bipolar junction transistor.

The light emitting unit 400 having such a configuration is connected to the light emitting controller 330 and the output pin 331 provided in the image sensor 300. Here, the output pin 331 is provided in the output pad region of the image sensor 300 to transmit an operation control signal applied from the light emission controller 330 to the light emitting unit 400.

Then, the light emitter 400 selectively turns on or off the transistor T1 according to an operation control signal applied from the light emission controller 330 to operate the light emitting devices 410 and 420 in response to the input level of the illuminance sensor 100. To control.

In this case, when an infrared (IR) light emitting diode (LED) is used as the light emitting devices 410 and 420, a dual band pass filter is included in the image sensor 300 to receive an infrared light source. Done. The dual band pass filter (not shown) may be included in the internal logic controller 320 to perform a filtering operation in the infrared light source applied from the lens 340.

5 is a view for explaining an operation of the light emission controller 330 of FIG. 4.

The light emission controller 330 emits light when the level of the illuminance sensor 100 applied through the internal logic controller 320 and the analog-digital converter 310 is low, that is, when the sensed illuminance is a T1 value of a dark level. Will be output On. Accordingly, when the sensed brightness information is at a dark level, the transistor T1 is turned on so that the light emitting devices 410 and 420 are turned on.

On the other hand, the light emission control unit 330 has a high level of the illumination sensor 100 applied through the internal logic control unit 320 and the analog-digital converter 310, that is, when the sensed illuminance is a bright level T2 value. The emission control signal is output off. Accordingly, when the sensed brightness information is at a bright level, the transistor T1 is turned off so that the light emitting devices 410 and 420 do not operate.

Here, T1 and T2 values representing threshold points for turning on or off the light emitting devices 410 and 420 corresponding to the level of the illumination sensor 100 are stored in the register 200. Accordingly, the image sensor 300 collects illuminance information around the current sensor through the illuminance sensor 100 and operates the light emitting elements 410 and 420 at the time points T1 and T2 using information previously stored in the register 200. To control.

In this case, when the light emitting devices 410 and 420 are formed of infrared (IR) light emitting diodes (LEDs), the internal logic controller 320 converts the image to a black and white mode while the infrared light emitting diodes are turned on. That is, when the image sensor 300 is a color sensor, the color resolution may deteriorate when the infrared light emitting diodes are used as the light emitting elements 410 and 420. When the infrared light emitting diode is turned on, the image is switched to the black and white mode.

1 is a block diagram of a photographing apparatus including a conventional image sensor.

2 is a block diagram of a photographing apparatus including an image sensor according to the present invention;

3 is a detailed circuit diagram of an illuminance sensor of FIG.

4 is a detailed circuit diagram of a light emitting part of FIG. 2.

FIG. 5 is a view for explaining the light emission controller of FIG. 2; FIG.

Claims (14)

An illumination sensor for sensing brightness information; An image sensor which takes an image and outputs an image signal; A light emitting part operating under the control of the image sensor and corresponding to the level of the brightness information; And An encoder for encoding the video signal applied from the image sensor and outputting a video signal; And the image sensor includes signal processing means for signal processing the brightness information applied from the illuminance sensor, and initializes the encoder according to initialization setting information stored in a register. The photographing apparatus of claim 1, wherein the signal processing means comprises an analog-to-digital converter for converting an analog signal for the brightness information into a digital signal. The image sensor of claim 1, wherein the image sensor An internal logic controller which controls the digital signal applied from the signal processing means to output the video signal; And And an image sensor for controlling an operation of the light emitting unit according to the output of the internal logic controller. The photographing apparatus of claim 3, wherein the internal logic controller is configured to switch to the black and white mode when the light emitter includes an infrared light emitting diode. The display apparatus of claim 3, wherein the light emission controller outputs a control signal for turning on the light emission unit when the brightness information corresponds to a first level having a dark level, and wherein the brightness information is a bright level and is higher than the first level. In case of the second level, a control signal for turning off the light emitting part is output, and values of the first level and the second level indicating a threshold time point for turning on or off the light emitting part are stored in the register. Imaging device comprising an image sensor, characterized in that. The image sensor of claim 1, further comprising a register configured to store information for controlling an operation time of the light emitter in response to the level of the brightness information. Shooting device. 7. The photographing apparatus of claim 6, wherein the register comprises an EEPROM. The photographing apparatus of claim 6, wherein the register is connected to one of the image sensor and an inter integrated circuit (I2C) bus or a serial peripheral interface (SPI) bus. delete The photographing apparatus of claim 1, wherein the encoder is connected to one of the image sensor and an inter integrated circuit (I2C) bus or a serial peripheral interface (SPI) bus. delete The photographing apparatus of claim 1, wherein the light emitting unit comprises one of a light emitting diode and an infrared light emitting diode. The photographing apparatus of claim 1, wherein the image sensor further comprises an input pin through which the brightness information is input from the illuminance sensor. The photographing apparatus of claim 1, wherein the image sensor further comprises an output pin configured to output an operation control signal to the light emitting unit.

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