JP2009027551A - Signal amplification module and camera system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a "signal amplification module and camera system" capable of immediately stabilizing the lightness of a screen or the like when introducing power supply to a camera or the like, while preventing the lightness of the screen or the like from being rapidly changed during traveling. <P>SOLUTION: Before the lapse of a prescribed time from the start of power supply, an amplification factor of an image signal is updated at time intervals shorter than time intervals after the lapse thereof, so that the lightness of a screen or the like can be immediately stabilized in a scene where an image from a camera is displayed for the first time by powering-on. After the lapse of the prescribed time, on the other hand, the amplification factor of the image signal is updated at time intervals longer than the time intervals before the lapse thereof, so that the lightness of the screen or the like is prevented from being rapidly changed during traveling. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a signal amplification module and a camera system, for example, a signal amplification module and a camera system suitable for use in equipment installed in a vehicle.

  Today, as part of increasing the added value of vehicles, camera systems are being installed in vehicles. In general, in the case of an in-vehicle camera system, time constants such as AGC (Automatic Gain Control) that automatically adjusts brightness and AWB (Auto White Balance) that automatically adjusts white balance are longer (for example, 1 second to 2 seconds). Second). Thereby, even if the brightness of the imaging target is suddenly switched by traveling of the vehicle, it is possible to prevent the brightness and color of the entire screen from changing suddenly, and to provide the passenger with an image with less discomfort.

  However, when the time constants such as AGC and AWB are long, the scene where the brightness and color of the screen should be stabilized immediately (for example, the scene where the image from the camera is first displayed when the power is turned on, the switching from the camera to another camera) There is a problem that it takes time until the brightness and color tone of the screen are stabilized in a scene where an image is first displayed. Although the problem can be solved if the camera system is always turned on, there is a disadvantage that the power consumption increases.

Note that an imaging apparatus that controls the time constant of AWB in accordance with the amount of change in the white balance target value is disclosed (for example, see Patent Document 1).
JP 2001-320726 A

  The present invention has been made to solve such problems. In other words, it was made to solve the problem that it takes time for the screen brightness and color to stabilize in a scene where the screen brightness and color should be stabilized immediately. The purpose is to immediately stabilize the brightness and hue of the screen in a scene where the brightness and hue of the screen should be immediately stabilized while preventing the brightness and hue of the screen from abruptly changing.

  In order to solve the above-described problem, in the first configuration of the present invention, before a predetermined time elapses from the start of power supply, a time interval after a predetermined time elapses from the start of power supply. The amplification factor is updated at short time intervals.

  In order to solve the above-described problem, in the second configuration of the present invention, a predetermined time from the start of image output to the display unit is passed before the predetermined time elapses from the start of image output to the display unit. The amplification factor is updated at a time interval shorter than the time interval after elapse of.

  According to the first configuration of the present invention configured as described above, before a predetermined time elapses from the start of power supply, the time interval after a predetermined time elapses from the start of power supply is shorter. The amplification factor is updated at time intervals. As a result, while the vehicle is running, the brightness and color tone of the entire screen are prevented from changing suddenly, and the screen brightness and color tone are immediately stabilized when the image from the camera is first displayed when the power is turned on. Can be made.

  According to the second configuration of the present invention configured as described above, before a predetermined time elapses from the start of image output to the display unit, the predetermined time elapses from the start of image output to the display unit. The amplification factor is updated at a time interval shorter than the time interval after elapses. As a result, while the vehicle is running, while the brightness and color of the entire screen are prevented from changing suddenly, the image from the camera is first displayed when the power is turned on, or from another camera by switching the camera. In the scene where the first image is displayed, the brightness and color of the screen can be immediately stabilized.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration example of a camera system 10 to which the signal amplification module 200 of the present embodiment is applied. As shown in FIG. 1, the camera system 10 includes a camera unit 100, an operation unit 410, a power supply unit 420, and a display unit 450.

  The operation unit 410 receives a power ON operation from a user of the camera system 10. The power supply unit 420 supplies power to the camera system 10 based on an operation from a user received via the operation unit 410. The display unit 450 acquires an image signal from the camera unit 100 and displays an image.

  The camera unit 100 includes an imaging module 300 and a signal amplification module 200. The imaging module 300 includes an optical lens 310 and a CCD 320 (corresponding to the imaging device of the present invention). The optical lens 310 forms an optical image of the subject on the photosensitive surface of the CCD 320. The CCD 320 periodically converts the formed optical image of the subject into an electrical signal (image signal) by photoelectric conversion. The CCD 320 sequentially outputs the converted image signal to the signal amplification module 200.

  The signal amplification module 200 includes an amplifier (AMP) 205 (corresponding to the first amplification unit of the present invention), an A / D conversion unit 210, a pixel value adjustment unit 215 (corresponding to the second amplification unit of the present invention), a camera. A signal processing unit 220, a color temperature detection unit 230, a comparison unit 240, a time determination unit 250, an integrator 260, a color temperature control unit 270, and a D / A conversion unit 280 are provided. Note that components other than the AMP 205, the A / D conversion unit 210, and the D / A conversion unit 280 may be configured by a DSP (Digital Signal Processor), for example.

  The AMP 205 of the signal amplification module 200 continuously obtains image signals (hereinafter referred to as analog image signals) from the CCD 320, and sequentially amplifies the continuously obtained analog image signals. More specifically, the AMP 205 periodically acquires an update value of an amplification factor (hereinafter referred to as analog gain) when the analog image signal is amplified from the integrator 260 via the D / A conversion unit 280. Then, the AMP 205 sequentially amplifies the analog image signal acquired continuously from the CCD 320 by using an analog gain update value acquired periodically. The AMP 205 continuously outputs the amplified analog signal (hereinafter referred to as the amplified analog signal) to the A / D conversion unit 210. The analog gain may be 1 or less.

  The A / D converter 210 of the signal amplifying module 200 continuously acquires the amplified analog signal from the AMP 205, and uses the acquired analog signal after the amplification as a pixel value in the RGB color space (hereinafter referred to as an R channel pixel). The analog / digital conversion is sequentially performed to R value, G channel pixel value as G value, and B channel pixel value as B value). The A / D converter 210 continuously outputs the R value, the G value, and the B value to the pixel value adjusting unit 215.

  The pixel value adjustment unit 215 of the signal amplification module 200 continuously acquires the R value, the G value, and the B value from the A / D conversion unit 210, and sequentially amplifies the acquired R value, G value, and B value. To do. More specifically, the pixel value adjustment unit 215 determines the update value of each amplification factor (hereinafter referred to as R value gain, G value gain, and B value gain) when amplifying the R value, G value, and B value, It is periodically acquired from the integrator 260 via the temperature controller 270. Then, the pixel value adjustment unit 215 periodically updates the R value, G value, and B value obtained from the A / D conversion unit 210, and the R value gain, G value gain, and B value gain update values are obtained periodically. Are sequentially amplified. The pixel value adjustment unit 215 continuously outputs the amplified R value, G value, and B value (hereinafter referred to as the amplified R value, the amplified G value, and the amplified B value) to the camera signal processing unit 220. The R value gain, the G value gain, and the B value gain may be 1 or less.

  The camera signal processing unit 220 of the signal amplification module 200 continuously obtains the amplified R value, the amplified G value, and the amplified B value from the pixel value adjusting unit 215, and continuously obtains the amplified R value and amplified. The post-G value and the post-amplification B value are sequentially converted into a luminance value Y of the luminance component, a color difference value Cb of the blue color difference component, and a color difference value Cr of the red color difference component. The camera signal processing unit 220 continuously outputs the luminance value Y, the color difference value Cb, and the color difference value Cr to the display unit 450.

  The time determination unit 250 of the signal amplification module 200 measures an elapsed time from the start of output when the camera signal processing unit 220 starts outputting the luminance value Y, the color difference value Cb, and the color difference value Cr to the display unit 450. When the time determination unit 250 determines that a predetermined time has elapsed from the start of output, the time determination unit 250 outputs a notification indicating that the predetermined time has elapsed from the start of output (hereinafter referred to as an output progress notification) to the integrator 260. To do.

  In addition, the time determination unit 250 measures an elapsed time from the start of power supply when the power supply unit 420 starts to supply power to the signal amplification module 100. When the time determination unit 250 determines that a predetermined time has elapsed since the start of power supply, the time determination unit 250 provides a notification indicating that the predetermined time has elapsed since the start of power supply (hereinafter referred to as a power supply progress notification). Output to the integrator 260.

  The comparison unit 240 of the signal amplification module 200 continuously acquires the luminance value Y from the camera signal processing unit 220, and compares the acquired luminance value Y with a reference value (corresponding to the predetermined luminance value of the present invention). The comparison unit 240 continuously outputs the comparison result to the integrator 260.

  The color temperature detection unit 230 of the signal amplification module 200 detects the color temperature by continuously acquiring the R value, the G value, and the B value output from the A / D conversion unit 210. The color temperature detection unit 230 continuously outputs the detected color temperature to the integrator 260.

  The integrator 260 of the signal amplification module 200 continuously obtains the comparison result from the comparison unit 240, and calculates the above-described analog gain update value according to the comparison result. The integrator 260 outputs the calculated analog gain update value to the D / A converter 280.

  Here, the integrator 260 outputs the updated value of the analog gain to the D / A converter 280 at the first time interval before a predetermined time has elapsed from the start of output, while the integrator 260 outputs the predetermined value from the start of output. After the time has elapsed, the analog gain update value is output to the D / A converter 280 at a second time interval longer than the first time interval.

  Specifically, the integrator 260 acquires within the first time interval described above before the output progress notification is output from the time determination unit 250, that is, before a predetermined time has elapsed from the start of output. An integrated value obtained by integrating (accumulating) the comparison results for X times is calculated, and an updated value of the analog gain is calculated based on a value obtained by dividing the calculated integrated value for the X times by X times. The integrator 260 outputs the calculated analog gain update value to the D / A converter 280 each time the analog gain update value is calculated.

  On the other hand, after the output progress notification is output from the time determination unit 250, that is, after a predetermined time has elapsed since the start of output, the integrator 260 starts from the X times acquired within the second time interval described above. Then, an integrated value obtained by integrating the comparison results for many Y times is calculated, and an updated value of the analog gain is calculated based on a value obtained by dividing the integrated value of the calculated comparison results for Y times by Y times. The integrator 260 outputs the calculated analog gain update value to the D / A converter 280 each time the analog gain update value is calculated.

  Further, the integrator 260 outputs the updated value of the analog gain to the D / A converter 280 at the first time interval before the predetermined time has elapsed from the start of power supply, in addition to the start of output. After a predetermined time has elapsed since the start of power supply, the analog gain update value is output to the D / A converter 280 at a second time interval longer than the first time interval.

  Specifically, the integrator 260 is acquired within the first time interval before the power supply progress notification is output from the time determination unit 250, that is, before a predetermined time has elapsed since the start of power supply. An integrated value obtained by integrating the comparison results for X times is calculated, and an updated value of the analog gain is calculated based on a value obtained by dividing the integrated value of the calculated comparison results for X times by X times. The integrator 260 outputs the calculated analog gain update value to the D / A converter 280 each time the analog gain update value is calculated.

  On the other hand, after the power supply progress notification is output from the time determination unit 250, that is, after a predetermined time has elapsed since the start of power supply, the integrator 260 acquires X times within the second time interval. An integrated value obtained by integrating more comparison results of Y times is calculated, and an updated value of the analog gain is calculated based on a value obtained by dividing the calculated integration value of Y times by Y times. The integrator 260 outputs the calculated analog gain update value to the D / A converter 280 each time the analog gain update value is calculated.

  Further, the integrator 260 continuously acquires the color temperature from the color temperature detection unit 230, and calculates the respective updated values of the R value gain, the G value gain, and the B value gain according to the color temperature. The integrator 260 outputs the calculated update values of the R value gain, the G value gain, and the B value gain to the color temperature control unit 270.

  Here, the integrator 260 outputs the updated values of the R value gain, the G value gain, and the B value gain to the color temperature control unit 270 at a first time interval before a predetermined time elapses from the output start time. On the other hand, after a predetermined time has elapsed from the start of output, the color temperature control unit 270 updates the R value gain, the G value gain, and the B value gain at a second time interval longer than the first time interval. Output to.

  Specifically, the integrator 260 acquires within the first time interval described above before the output progress notification is output from the time determination unit 250, that is, before a predetermined time has elapsed from the start of output. An integral value obtained by integrating the color temperature for X times is calculated, and each update value of the R value gain, the G value gain, and the B value gain is calculated based on a value obtained by dividing the calculated integration value of the X times by X times. calculate. Each time the integrator 260 calculates the updated values of the R value gain, the G value gain, and the B value gain, the integrator 260 supplies the calculated updated values of the R value gain, the G value gain, and the B value gain to the color temperature control unit 270. Output.

  On the other hand, after the output progress notification is output from the time determination unit 250, that is, after a predetermined time has elapsed since the start of output, the integrator 260 starts from the X times acquired within the second time interval described above. An integral value obtained by integrating the color temperature for Y times is calculated, and each of the R value gain, the G value gain, and the B value gain is updated based on a value obtained by dividing the calculated Y color temperature integral value by Y times. Calculate the value. Each time the integrator 260 calculates the updated values of the R value gain, the G value gain, and the B value gain, the integrator 260 supplies the calculated updated values of the R value gain, the G value gain, and the B value gain to the color temperature control unit 270. Output.

  Further, the integrator 260 colors each update value of the R value gain, the G value gain, and the B value gain at a first time interval before a predetermined time has elapsed since the start of power supply in addition to the output start time. While outputting to the temperature control unit 270, after a predetermined time has elapsed from the start of power supply, the analog gain update value is output to the color temperature control unit 270 at a second time interval longer than the first time interval. To do.

  Specifically, the integrator 260 is acquired within the first time interval before the power supply progress notification is output from the time determination unit 250, that is, before a predetermined time has elapsed since the start of power supply. An integrated value obtained by integrating the X color temperatures is calculated, and each of the updated values of the R value gain, the G value gain, and the B value gain is calculated based on a value obtained by dividing the calculated integrated value of the X color temperature by the X times. Is calculated. Each time the integrator 260 calculates the updated values of the R value gain, the G value gain, and the B value gain, the integrator 260 supplies the calculated updated values of the R value gain, the G value gain, and the B value gain to the color temperature control unit 270. Output.

  On the other hand, after the power supply progress notification is output from the time determination unit 250, that is, after a predetermined time has elapsed since the start of power supply, the integrator 260 acquires X times within the second time interval. An integral value obtained by integrating more than Y color temperatures is calculated, and each of R value gain, G value gain, and B value gain is calculated based on a value obtained by dividing the calculated Y color temperature integral value by Y times. Update value is calculated. Each time the integrator 260 calculates the updated values of the R value gain, the G value gain, and the B value gain, the integrator 260 supplies the calculated updated values of the R value gain, the G value gain, and the B value gain to the color temperature control unit 270. Output.

  The D / A conversion unit 280 of the signal amplification module 200 acquires the updated value of the analog gain from the integrator 260 and performs digital / analog conversion on the acquired updated value of the analog gain. The D / A conversion unit 280 outputs the analog gain update value converted into the analog value to the AMP 205.

  The color temperature control unit 270 of the signal amplification module 200 acquires the updated values of the R value gain, the G value gain, and the B value gain from the integrator 260, and acquires each of the acquired R value gain, G value gain, and B value gain. The update value is output to the pixel value adjustment unit 215.

  Hereinafter, the operation of the camera system 10 configured as described above will be described. FIG. 2 is a flowchart showing an example of the operation of the camera system 10 shown in FIG. This flowchart shows the first time interval (for example, 0.1 second) before a predetermined time (for example, 2 seconds) has elapsed from the start of power supply, and the second time after the predetermined time has elapsed. This is an example of the operation when the analog gain, the R value gain, the G value gain, and the B value gain are updated at intervals (for example, 1 second), and starts when the power supply unit 420 supplies power to the camera system 10 To do. It is assumed that the initial values of the analog gain, R value gain, G value gain, and B value gain are “1 (no amplification)”.

  The time determination unit 250 of the signal amplification module 200 starts measuring the elapsed time from the start of power supply (step S100). The time determination unit 250 outputs the above-described power supply progress notification to the integrator 260 when a predetermined time (2 seconds) has elapsed since the start of power supply.

  The AMP 205 acquires an analog image signal for one frame from the CCD 320, and updates the acquired analog image signal for one frame with an analog gain value (initial value or an updated value in step S350 described later). Value) (step S200). The AMP 205 supplies the amplified analog signal to the A / D conversion unit 210.

  The A / D converter 210 of the signal amplification module 200 acquires the amplified analog signal from the AMP 205, and performs analog / digital conversion of the acquired amplified analog signal into an R value, a G value, and a B value (step S210). The A / D conversion unit 210 outputs the R value, the G value, and the B value to the pixel value adjustment unit 215.

  The color temperature detection unit 230 of the signal amplification module 200 acquires the R value, G value, and B value output from the A / D conversion unit 210 and detects the color temperature. The color temperature detection unit 230 outputs the detected color temperature to the integrator 260. The integrator 260 acquires the color temperature from the color temperature detection unit 230 and integrates it (step S220).

  The pixel value adjustment unit 215 of the signal amplification module 200 acquires the R value, the G value, and the B value from the A / D conversion unit 210, and uses the acquired R value, G value, and B value as the R value gain, G value gain, and Each B value gain is amplified by each value (each initial value or each updated value when each updated value is acquired in step S350 described later) (step S230). The pixel value adjustment unit 215 outputs the amplified R value, the amplified G value, and the amplified B value to the camera signal processing unit 220.

  The camera signal processing unit 220 of the signal amplification module 200 acquires the post-amplification R value, the post-amplification G value, and the post-amplification B value from the pixel value adjustment unit 215, and the acquired post-amplification R value, post-amplification G value, and post-amplification The B value is converted into a luminance value Y, a color difference value Cb, and a color difference value Cr (step S240). The camera signal processing unit 220 outputs the luminance value Y, the color difference value Cb, and the color difference value Cr to the display unit 450.

  The comparison unit 240 of the signal amplification module 200 acquires the luminance value Y from the camera signal processing unit 220, and compares the acquired luminance value Y with a reference value. Comparison unit 240 outputs the comparison result to integrator 260. The integrator 260 acquires and integrates the comparison result from the comparison unit 240 (step S250). The display unit 450 acquires the luminance value Y, the color difference value Cb, and the color difference value Cr from the camera signal processing unit 220, and displays an image (step S400).

  The integrator 260 of the signal amplification module 200 determines whether or not a predetermined time (2 seconds) has elapsed since the start of power supply (step S500). When integrator 260 determines that a predetermined time has not elapsed since the start of power supply, that is, when integrator 260 determines that a power supply progress notification has not been supplied from time determination unit 250 (step S500: No), the integrator 260 determines whether or not the period time (0.1 second) of the first time interval has elapsed (step S510).

  On the other hand, when integrator 260 determines that a predetermined time has elapsed since the start of power supply, that is, when integrator 260 determines that a power supply progress notification has been supplied from time determination unit 250 (step S500: Yes), the integrator 260 determines whether or not the period time (1 second) of the second time interval has elapsed (step S520).

  When the integrator 260 determines that the period time (0.1 second) of the first time interval has elapsed (step S510: Yes), the integrator 260 is within the first time interval (0.1. Update value of analog gain is calculated based on the value obtained by dividing the integral value of the comparison result for X times acquired in seconds) by X times, and X times acquired in the first time interval (0.1 seconds) Each update value of the R value gain, G value gain, and B value gain is calculated based on a value obtained by dividing the integrated value of the color temperature by X times (step S530). The integrator 260 outputs the updated value of the analog gain to the AMP 205 via the D / A conversion unit 280, and the updated value of the R value gain, the G value gain, and the B value gain via the color temperature control unit 270. To the pixel value adjustment unit 215.

  When the integrator 260 determines that the period time (1 second) of the second time interval has elapsed (step S520: Yes), the integrator 260 acquires within the second time interval (1 second). The updated value of the analog gain is calculated based on the value obtained by dividing the integrated value of the Y comparison results by Y times, and the Y color temperature integrated value acquired within the second time interval (1 second). Each update value of the R value gain, G value gain, and B value gain is calculated based on the value obtained by dividing Y by Y times (step S530). The integrator 260 outputs the updated value of the analog gain to the AMP 205 via the D / A conversion unit 280, and the updated value of the R value gain, the G value gain, and the B value gain via the color temperature control unit 270. To the pixel value adjustment unit 215.

  Subsequent to step S530, the AMP 205 that acquired the updated value of the analog gain from the integrator 260 updates the analog gain value (initial value or updated value of the previously acquired analog gain) with the updated value acquired this time (step S530). S540). In addition, following step S530, the pixel value adjustment unit 215 that has acquired the updated values of the R value gain, the G value gain, and the B value gain from the integrator 260 includes the R value gain, the G value gain, and the B value gain. The value (each initial value or each update value acquired last time) is updated with each update value acquired this time (step S540).

  On the other hand, when the integrator 260 determines that the period time (0.1 second) of the first time interval has not elapsed (step S510: No), or the period time of the second time interval (1 second) ) Has not elapsed (step S520: No), step S530 and step S540 are skipped and the process proceeds to step S570.

  The operation unit 410 determines whether or not an input to end the operation of the camera system 10 has been received (step S570). If the operation unit 410 determines that an input to end the operation of the camera system 10 has been received (step S570: Yes), this flowchart ends.

  On the other hand, when the operation unit 410 determines that an input to end the operation of the camera system 10 has not been received (step S570: No), the process returns to step S200. When the process returns to step S200, the AMP 205 acquires an analog image signal for the next one frame from the CCD 320. In addition, it is preferable that the period which performs step S200 is the same as a frame rate.

  Next, other operations relating to the camera system 10 shown in FIG. 1 will be described. FIG. 3 is a flowchart showing an example of another operation related to the camera system 10 shown in FIG. This flowchart shows a first time interval (0.1 second) before a predetermined time (2 seconds) has elapsed from the start of output to the display unit 450, and a second time interval after the predetermined time has elapsed. This is an example of the operation when the analog gain, R value gain, G value gain, and B value gain are updated in (1 second), and the CCD 320 outputs an image signal for one frame to the signal amplification module 200. Start. It is assumed that the initial values of the analog gain, R value gain, G value gain, and B value gain are “1 (no amplification)”.

  The AMP 205 amplifies the analog image signal acquired from the CCD 320 as in step S200 of FIG. 2 (step S202). The AMP 205 supplies the amplified analog signal to the A / D conversion unit 210. As in step S210 of FIG. 2, the A / D conversion unit 210 converts the amplified analog signal acquired from the AMP 205 into an R value, a G value, and a B value, and outputs them to the pixel value adjustment unit 215 (step S212). ).

  The color temperature detection unit 230 acquires the R value, the G value, and the B value, detects the color temperature, and outputs it to the integrator 260, as in step S220 of FIG. The integrator 260 acquires the color temperature from the color temperature detection unit 230 and integrates it (step S222). The pixel value adjustment unit 215 amplifies the R value, the G value, and the B value acquired from the A / D conversion unit 210, similarly to step S230 in FIG. 2 (step S232). The pixel value adjustment unit 215 outputs the amplified R value, the amplified G value, and the amplified B value to the camera signal processing unit 220.

  The camera signal processing unit 220 uses the amplified R value, the amplified G value, and the amplified B value acquired from the pixel value adjusting unit 215 as the luminance value Y, the color difference value Cb, and the color difference value, as in step S240 of FIG. Conversion into Cr is performed (step S242). The camera signal processing unit 220 outputs the luminance value Y, the color difference value Cb, and the color difference value Cr to the display unit 450.

  The comparison unit 240 compares the luminance value Y acquired from the camera signal processing unit 220 with the reference value, and outputs the comparison result to the integrator 260, similarly to step S250 of FIG. The integrator 260 acquires the comparison result from the comparison unit 240 and integrates it (step S252).

  The time determination unit 250 starts measuring the elapsed time from the start of output when the camera signal processing unit 220 starts outputting the luminance value Y, the color difference value Cb, and the color difference value Cr to the display unit 450 (step S300). Note that the time determination unit 250 does not execute this process when the measurement of the elapsed time from the start of output has already started. The time determination unit 250 supplies the above-described output progress notification to the integrator 260 when a predetermined time (2 seconds) has elapsed since the start of output.

  The display unit 450 acquires the luminance value Y, the color difference value Cb, and the color difference value Cr from the camera signal processing unit 220, and displays an image (step S402). The integrator 260 determines whether or not a predetermined time (2 seconds) has elapsed since the start of output (step S502). When integrator 260 determines that a predetermined time has not elapsed since the start of output, that is, when integrator 260 determines that an output progress notification has not been supplied from time determination unit 250 (step S502: No) ), The integrator 260 determines whether or not the cycle time (0.1 second) of the first time interval has elapsed (step S512).

  On the other hand, when the integrator 260 determines that a predetermined time has elapsed since the start of output, that is, when the integrator 260 determines that an output progress notification is supplied from the time determination unit 250 (step S502: Yes), The integrator 260 determines whether or not the period time (1 second) of the second time interval has elapsed (step S522).

  When the integrator 260 determines that the period time (0.1 second) of the first time interval has elapsed (step S512: Yes), or the period time (1 second) of the second time interval has elapsed. When the integrator 260 determines (step S522: Yes), the operation (step S532 and step S542) is the same as step S530 and step S540 in FIG.

  The operation unit 410 determines whether or not an input to end the operation of the camera system 10 has been received (step S572), similarly to step S570 in FIG. When the operation unit 410 determines that an input to end the operation of the camera system 10 has been received (step S572: Yes), this flowchart ends.

  On the other hand, when the operation unit 410 determines that an input to end the operation of the camera system 10 has not been received (step S572: No), the process returns to step S202. When the process returns to step S202, the AMP 205 acquires an analog image signal for the next one frame from the CCD 320. In addition, it is preferable that the period which performs step S202 is the same as a frame rate.

  Hereinafter, another configuration example regarding the camera system to which the signal amplification module of the present embodiment is applied will be described. FIG. 4 is a diagram illustrating a configuration example of another camera system 12 to which the signal amplification module of the present embodiment is applied. FIG. 5 is a diagram illustrating a configuration example of the signal amplification module 600 illustrated in FIG.

  As shown in FIG. 4, the camera system 12 includes camera units 500 and 502, an operation unit 412, a power supply unit 422, a gear information acquisition unit 432, a selection unit 442, and a display unit 452.

  The operation unit 412 receives a power ON operation and a camera selection operation from a user of the camera system 12. The power supply unit 422 supplies power to the camera system 12 based on a power ON operation from the user received via the operation unit 412. In addition, the power supply unit 422 can be used when the engine is started when the key 424 is inserted into the keyhole 426 in place of or in addition to the operation of turning on the power from a user received via the operation unit 412. You may supply electric power to. The gear information acquisition unit 432 acquires the change information of the gear 434 of the vehicle and outputs it to the selection unit 442.

  The selection unit 442 selects one camera unit that displays a captured image on the display unit 452 from the camera unit 500 or the camera unit 502. Specifically, the selection unit 442 selects one camera unit based on the operation from the user received via the operation unit 412.

  The selection unit 442 selects one camera unit based on the change information of the gear 434 acquired from the gear information acquisition unit 432. For example, when acquiring the change information of the gear 434 from the gear information acquisition unit 432, the selection unit 442 identifies the gear identification information for identifying the changed gear indicated by the change information of the gear 434 and the camera units 500 and 502. One camera unit identified by the camera identification information associated with the gear identification information indicated by the acquired change information of the gear 434 is selected with reference to the correspondence table in which the camera identification information is associated.

  Further, the selection unit 442 outputs an image signal output from the selected camera unit 500 or camera unit 502 to the display unit 452. The display unit 452 acquires an image signal from the camera unit 500 or the camera unit 502 via the selection unit 442 and displays an image.

  The camera unit 500 includes an imaging module 700 and a signal amplification module 600. Since the imaging module 700 is the same as the imaging module 300 of the camera unit 100, description thereof is omitted. The camera unit 502 includes an imaging module 702 and a signal amplification module 602. Since the imaging module 702 is the same as the imaging module 300 of the camera unit 100, description thereof is omitted.

  As shown in FIG. 5, the signal amplification module 600 of the camera unit 500 includes an AMP 605, an A / D conversion unit 610, a pixel value adjustment unit 615, a camera signal processing unit 620, a color temperature detection unit 630, a comparison unit 640, and a time determination. Unit 650, integrator 660, color temperature control unit 670, and D / A conversion unit 680. Note that the AMP 605, the A / D conversion unit 610, the pixel value adjustment unit 615, the camera signal processing unit 620, the color temperature detection unit 630, the comparison unit 640, the color temperature control unit 670, and the D / A conversion unit 680 are illustrated in FIG. Since it is the same as each part of the signal amplifying module 200 shown, the description is omitted.

  The time determination unit 650 measures an elapsed time from the start of selection when the selection unit 442 starts selecting the camera unit 500. When the time determination unit 650 determines that a predetermined time has elapsed from the start of selection, the time determination unit 650 supplies a notification indicating that the predetermined time has elapsed from the start of selection (hereinafter referred to as a selection progress notification) to the integrator 660. To do.

  The integrator 660 outputs the updated value of the analog gain to the D / A converter 680 at the first time interval before the predetermined time has elapsed from the start of selection, while the predetermined time has elapsed from the start of selection. After that, the analog gain update value is output to the D / A converter 680 at a second time interval longer than the first time interval.

  Specifically, the integrator 660 acquires the information within the first time interval described above before the selection progress notification is supplied from the time determination unit 650, that is, before a predetermined time elapses from the selection start time. An integrated value obtained by integrating (accumulating) the comparison results for X times is calculated, and an updated value of the analog gain is calculated based on a value obtained by dividing the calculated integrated value for the X times by X times. The integrator 660 outputs the calculated analog gain update value to the D / A converter 680 each time the analog gain update value is calculated.

  On the other hand, after the selection progress notification is supplied from the time determination unit 650, that is, after a predetermined time has elapsed from the start of selection, the integrator 660 performs X times acquired within the second time interval described above. Then, an integrated value obtained by integrating the comparison results for many Y times is calculated, and an updated value of the analog gain is calculated based on a value obtained by dividing the integrated value of the calculated comparison results for Y times by Y times. The integrator 660 outputs the calculated analog gain update value to the D / A converter 680 each time the analog gain update value is calculated.

  Further, integrator 660 outputs the updated values of R value gain, G value gain, and B value gain to color temperature control unit 670 at a first time interval before a predetermined time has elapsed from the start of selection. On the other hand, after a predetermined time has elapsed from the start of selection, the updated values of R value gain, G value gain, and B value gain are sent to the color temperature control unit 670 at a second time interval longer than the first time interval. Output.

  Specifically, the integrator 660 acquires the information within the first time interval described above before the selection progress notification is supplied from the time determination unit 650, that is, before a predetermined time elapses from the selection start time. An integral value obtained by integrating the color temperature for X times is calculated, and each update value of the R value gain, the G value gain, and the B value gain is calculated based on a value obtained by dividing the calculated integration value of the X times by X times. calculate. Then, each time the integrator 660 calculates the updated values of the R value gain, the G value gain, and the B value gain, the integrator 660 sends the updated values of the calculated R value gain, G value gain, and B value gain to the color temperature control unit 670. Output.

  On the other hand, after the selection progress notification is supplied from the time determination unit 650, that is, after a predetermined time has elapsed from the start of selection, the integrator 660 performs X times acquired within the second time interval described above. An integral value obtained by integrating the color temperature for Y times is calculated, and each of the R value gain, the G value gain, and the B value gain is updated based on a value obtained by dividing the calculated Y color temperature integral value by Y times. Calculate the value. Then, each time the integrator 660 calculates the updated values of the R value gain, the G value gain, and the B value gain, the integrator 660 sends the updated values of the calculated R value gain, G value gain, and B value gain to the color temperature control unit 670. Output.

  Since the signal amplification module 602 of the camera unit 502 is the same as the signal amplification module 600 of the camera unit 500 described above, the description thereof is omitted.

  Hereinafter, the operation of the camera system 12 configured as described above will be described. FIG. 6 is a flowchart showing an example of the operation of the camera system 12 shown in FIG. This flowchart starts when the selection unit 442 switches the selection from one camera unit to another camera unit. Here, the selection unit 442 acquires change information indicating that the gear has been changed to the reverse gear from the gear information acquisition unit 432, and selects the camera unit 502 that images the front of the vehicle to the camera unit 500 that images the rear of the vehicle. An example of switching will be described. Further, various conditions such as a predetermined time and initial values such as analog gain are the same as those in the flowchart shown in FIG.

  The time determination unit 650 of the signal amplification module 600 included in the camera unit 500 starts measuring the elapsed time from the start of selection (step S104). Time determination unit 650 outputs the above selection progress notification to integrator 660 when a predetermined time has elapsed from the start of selection.

  The AMP 605 of the signal amplification module 600 amplifies the analog image signal acquired from the imaging module 700, similarly to step S200 of FIG. 2 (step S204). The AMP 605 supplies the amplified analog signal to the A / D conversion unit 610. The A / D conversion unit 610 converts the amplified analog signal acquired from the AMP 605 into an R value, a G value, and a B value, and outputs the R value, the G value, and the B value to the pixel value adjustment unit 215, similarly to step S210 in FIG. 2 (step S214). ).

  The color temperature detection unit 630 of the signal amplification module 600 acquires the R value, the G value, and the B value, detects the color temperature, and outputs it to the integrator 660 as in step S220 of FIG. The integrator 660 acquires the color temperature from the color temperature detection unit 630 and integrates it (step S224). The pixel value adjustment unit 615 amplifies the R value, the G value, and the B value acquired from the A / D conversion unit 610, similarly to step S230 of FIG. 2 (step S234). The pixel value adjustment unit 615 outputs the R value after amplification, the G value after amplification, and the B value after amplification to the camera signal processing unit 620.

  The camera signal processing unit 620 uses the amplified R value, the amplified G value, and the amplified B value acquired from the pixel value adjusting unit 615 as the luminance value Y, the color difference value Cb, and the color difference value, similarly to step S240 in FIG. Conversion into Cr is performed (step S244). The camera signal processing unit 620 outputs the luminance value Y, the color difference value Cb, and the color difference value Cr to the display unit 452 via the selection unit 442.

  The comparison unit 640 compares the luminance value Y acquired from the camera signal processing unit 620 with the reference value, and outputs the comparison result to the integrator 660, similarly to step S250 of FIG. The integrator 660 acquires the comparison result from the comparison unit 640 and integrates it (step S254).

  The display unit 452 acquires the luminance value Y, the color difference value Cb, and the color difference value Cr from the camera signal processing unit 220 via the selection unit 442, and displays an image (step S404). The integrator 660 determines whether or not a predetermined time has elapsed from the start of selection (step S504). When integrator 660 determines that a predetermined time has not elapsed since the start of selection, that is, when integrator 660 determines that the selection progress notification is not supplied from time determination unit 650 (step S504: No) ), Integrator 660 determines whether or not the period of the first time interval has elapsed (step S514).

  On the other hand, when the integrator 660 determines that a predetermined time has elapsed since the start of selection, that is, when the integrator 660 determines that a selection progress notification has been supplied from the time determination unit 650 (step S504: Yes), The integrator 660 determines whether or not the cycle time of the second time interval has elapsed (step S524).

  When integrator 660 determines that the period of the first time interval has elapsed (step S514: Yes), or when it is determined by integrator 660 that the period of the second time interval has elapsed ( The operation (step S524: Yes) (step S534 and step S544) is the same as step S530 and step S540 in FIG.

  The operation unit 412 determines whether or not an input to end the operation of the camera system 12 has been received (step S574), similarly to step S570 in FIG. When the operation unit 412 determines that an input to end the operation of the camera system 12 has been received (step S574: Yes), this flowchart ends.

  On the other hand, when the operation unit 412 determines that an input to end the operation of the camera system 12 has not been received (step S574: No), the process returns to step S204. It should be noted that the cycle for executing step S204 is preferably the same as the frame rate.

  FIG. 7 is a diagram illustrating a relationship between a predetermined elapsed time and the first and second time intervals. In the camera system 10 shown in the flowchart of FIG. 2, as shown in FIG. 7A, before a predetermined time t1 (= 2 seconds) elapses from the start of power supply, the first time interval T1 (= While updating the amplification factor (update values of analog gain, R value gain, G value gain, and B value gain) at intervals of 0.1 seconds, a predetermined time t1 (= 2) from the start of power supply After the second), the amplification factor is updated at the second time interval T2 (= 1 second interval).

  Therefore, for example, when the vehicle is running, the brightness and color of the entire screen are prevented from changing suddenly, while the image from the camera is first displayed when the power is turned on. It can be stabilized.

  Further, in the camera system 10 shown in the flowchart of FIG. 3, as shown in FIG. 7B, the first time t2 (= 2 seconds) elapses from the start of output to the display unit 450. While the amplification factor is updated at the time interval T1 (= 0.1 second interval), after a predetermined time t2 (= 2 seconds) has elapsed from the start of output to the display unit 450, the second time interval T2 ( = Amplification rate is updated every 1 second).

  Therefore, for example, when the vehicle is running, the brightness and color of the entire screen are prevented from changing suddenly, and in the scene where the image from the camera is first displayed, the brightness and color of the screen are immediately stabilized. Can do. The predetermined time t2 may be different from the predetermined time t1 in FIG.

  Further, in the camera system 12 shown in the flowchart of FIG. 6, as shown in FIG. 7C, before the predetermined time t3 (= 2 seconds) elapses from the start of selection of the camera units 500 and 502, the first While the amplification factor is updated at the time interval T1 (= 0.1 second interval), after the predetermined time t2 (= 2 seconds) has elapsed from the start of the selection of the camera units 500 and 502, the second time interval is updated. The amplification factor is updated at T2 (= 1 second interval).

  Therefore, for example, when the vehicle is running, the brightness and color of the entire screen are prevented from changing suddenly, and the camera is switched in the vehicle (for example, when the back shift lever is inserted). The brightness and color of the screen can be immediately stabilized in the camera. Note that the predetermined time t3 may be different from the predetermined time t1 in FIG. 7A and the predetermined time t2 in FIG. 7B.

  As described above, according to the present embodiment, while the vehicle is running, a scene where the image from the camera is first displayed by turning on the power while preventing the brightness and color of the entire screen from changing suddenly, or the camera In a scene where an image from another camera is first displayed by switching, the brightness and hue of the screen can be immediately stabilized.

  In the present embodiment, the pixel value adjustment units 215 and 615 amplify the R value, the G value, and the B value by the updated values of the R value gain, the G value gain, and the B value gain, respectively. The value adjusting units 215 and 615 may amplify the R value and the B value excluding the G value by the updated values of the R value gain and the B value gain, respectively.

  In addition, each of the above-described embodiments is merely an example of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. In other words, the present invention can be implemented in various forms without departing from the spirit or main features thereof.

It is a figure which shows the structural example of the camera system to which the signal amplification module of this embodiment is applied. 3 is a flowchart illustrating an example of an operation of the camera system illustrated in FIG. 1. 7 is a flowchart showing an example of another operation related to the camera system shown in FIG. 1. It is a figure which shows the structural example of the other camera system to which the signal amplification module of this embodiment is applied. It is a figure which shows the structural example of the signal amplification module shown in FIG. 5 is a flowchart showing an example of the operation of the camera system shown in FIG. It is a figure which shows the relationship between predetermined elapsed time and a 1st, 2nd time interval.

Explanation of symbols

10 camera system 100 camera unit 200 signal amplification module 205 AMP
210 A / D conversion unit 215 Pixel value adjustment unit 220 Camera signal processing unit 230 Color temperature detection unit 240 Comparison unit 250 Time determination unit 260 Integrator 270 Color temperature control unit 280 D / A conversion unit 300 Imaging module 410 Operation unit 420 Power supply Part 450 Display part

Claims (10)

A signal amplification module that periodically updates the amplification factor, sequentially amplifies the continuously input image signal with the updated amplification factor, and continuously outputs the amplified image signal,
The amplification factor is updated at a first time interval before a predetermined time elapses from the start of power supply to the signal amplification module, and after the predetermined time elapses at a second time interval. Update the amplification factor,
The signal amplification module according to claim 1, wherein the first time interval is shorter than the second time interval. A first amplifying unit that obtains an update value of the amplification factor, sequentially amplifies the continuously input image signal by the update value, and continuously outputs the amplified image signal;
Update that calculates the update value according to a comparison result between a luminance value based on the amplified image signal amplified by the first amplification unit and a predetermined luminance value, and supplies the updated value to the first amplification unit With a value calculator,
The update value calculation unit supplies the update value to the first amplification unit at the first time interval before a predetermined time elapses from the start of power supply to the signal amplification module. 2. The signal amplification module according to claim 1, wherein the updated value is supplied to the first amplifier at the second time interval after a predetermined time has elapsed. A second amplifying unit that obtains an update value of the amplification factor, sequentially amplifies the continuously input image signal by the update value, and continuously outputs the amplified image signal;
An update value calculation unit that calculates the update value according to a color temperature based on the image signal input to the second amplification unit and supplies the update value to the second amplification unit;
The update value calculation unit supplies the update value to the second amplification unit at the first time interval before a predetermined time elapses from the start of power supply to the signal amplification module. 2. The signal amplification module according to claim 1, wherein the updated value is supplied to the second amplification section at the second time interval after a predetermined time has elapsed. The amplification factor is periodically updated, and the image signal to be output to the display unit, which is continuously input, is sequentially amplified with the updated amplification factor, and the amplified image signal is continuously A signal amplifying module that outputs automatically,
The amplification factor is updated at a first time interval before a predetermined time elapses from the start of output of the image signal to the display unit, while at a second time interval after the predetermined time elapses. Update the above amplification factor,
The signal amplification module according to claim 1, wherein the first time interval is shorter than the second time interval. A first amplifying unit that obtains an update value of the amplification factor, sequentially amplifies the continuously input image signal by the update value, and continuously outputs the amplified image signal;
Update that calculates the update value according to a comparison result between a luminance value based on the amplified image signal amplified by the first amplification unit and a predetermined luminance value, and supplies the updated value to the first amplification unit With a value calculator,
The update value calculation unit supplies the update value to the first amplification unit at the first time interval before a predetermined time elapses from the start of output of the image signal to the display unit. 2. The signal amplification module according to claim 1, wherein the updated value is supplied to the first amplification unit at the second time interval after the predetermined time has elapsed. A second amplifying unit that obtains an update value of the amplification factor, sequentially amplifies the continuously input image signal by the update value, and continuously outputs the amplified image signal;
An update value calculation unit that calculates the update value according to a color temperature based on the image signal input to the second amplification unit and supplies the update value to the second amplification unit;
The update value calculation unit supplies the update value to the second amplification unit at the first time interval before a predetermined time elapses from the start of output of the image signal to the display unit. 2. The signal amplification module according to claim 1, wherein the updated value is supplied to the second amplifying unit at the second time interval after the predetermined time has elapsed. A camera system comprising a camera unit and a display unit that is connected to the camera unit and displays a captured image captured by the camera unit,
The camera unit includes an imaging module having an optical lens and an imaging device, periodically updates the amplification factor, sequentially amplifies continuously input image signals with the updated amplification factor, A signal amplification module that continuously outputs the image signal to the display unit;
The signal amplification module included in the camera unit updates the amplification factor at a first time interval before a predetermined time elapses from the start of power supply to the camera system, while the predetermined time elapses. After that, update the amplification factor at the second time interval,
The camera system according to claim 1, wherein the first time interval is shorter than the second time interval. A camera system comprising a camera unit and a display unit that is connected to the camera unit and displays a captured image captured by the camera unit,
The camera unit includes an imaging module having an optical lens and an imaging device, periodically updates the amplification factor, sequentially amplifies continuously input image signals with the updated amplification factor, A signal amplification module that continuously outputs the image signal to the display unit;
The signal amplification module included in the camera unit updates the amplification factor at a first time interval before a predetermined time elapses from the start of output of the image signal to the display unit. After the elapse of time, the amplification factor is updated at the second time interval,
The camera system according to claim 1, wherein the first time interval is shorter than the second time interval. A plurality of camera units; a display unit that is connected to the plurality of camera units and displays a captured image captured by the camera unit; and the display unit that displays the captured image from the plurality of camera units. A camera system including a selection unit that selects the camera unit,
Each of the camera units has an imaging module having an optical lens and an imaging device, periodically updates the amplification factor, and sequentially amplifies the image signal that is input continuously by the updated amplification factor. A signal amplifying module for continuously outputting the subsequent image signal to the display unit;
When the selection unit selects one camera unit, the signal amplification module included in the camera unit performs the amplification at a first time interval before a predetermined time elapses from when the camera unit is selected. While the rate is updated, after the predetermined time has elapsed, the gain is updated at a second time interval,
The camera system according to claim 1, wherein the first time interval is shorter than the second time interval. The plurality of camera units are installed in a vehicle,
A gear information acquisition unit connected to the selection unit for acquiring gear change information of the vehicle;
The selection unit selects one camera unit that captures an image of the rear of the vehicle from the plurality of camera units when the change information indicating the change to the reverse gear is acquired from the gear information acquisition unit. The camera system according to claim 9.